JP5040907B2 - Refrigeration equipment - Google Patents

Description

  The present invention relates to a refrigeration apparatus for a two-stage compression refrigeration cycle, and more particularly to a technique for adjusting a ratio of suction volume in a compressor in which a plurality of compression mechanisms are mechanically connected by a single drive shaft.

Conventionally, a refrigeration apparatus that performs a two-stage compression refrigeration cycle is known. In this refrigeration apparatus, for example, a compression mechanism in which two compression mechanisms are mechanically coupled to one drive shaft is used (see, for example, Patent Document 1). In the compressor of the refrigeration apparatus, one compression mechanism is a low-stage compression mechanism, and the other compression mechanism is a high-stage compression mechanism.
JP 2007-23993 A

  Here, for example, in a refrigeration cycle using carbon dioxide as a refrigerant, there is a problem that heat dissipation loss is large and it is difficult to obtain a high COP. Therefore, COP can be increased by performing multistage compression as described above. At this time, the intermediate pressure changes depending on the volume ratio of the low-stage compression mechanism and the high-stage compression mechanism. However, since the COP changes when the intermediate pressure changes, it is desirable to optimally control the intermediate pressure.

  When there are two compressors, a low-stage compressor and a high-stage compressor, the COP is changed by changing the refrigerant intake ratio (volume ratio) by changing the rotation speed of each compressor. Can be controlled. However, in a compressor in which two compression mechanisms are connected to one drive shaft as described in Patent Document 1, since the rotational speeds of the low-stage compression mechanism and the high-stage compression mechanism are equal, The suction volume ratio between the side compression mechanism and the high stage compression mechanism becomes constant, and the intermediate pressure cannot be controlled. This is not limited to the case where the refrigerant is carbon dioxide, and the same applies when another refrigerant is used.

  The present invention has been devised by paying attention to such problems, and an object of the present invention is to provide a refrigeration apparatus that performs a two-stage compression refrigeration cycle in which a plurality of compression mechanisms are mechanically operated by a single drive shaft. It is possible to adjust the ratio of the suction volume in the connected compressors and thus to enable the operation of the optimum COP.

  The first invention is a compressor (1) (100) in which a plurality of compression mechanisms (20, 30) (110, 120, 130, 140) are mechanically connected by a single drive shaft (53) (173). ) Is connected to the refrigerant circuit (60) (180) connected to the refrigeration apparatus for performing the two-stage compression refrigeration cycle.

In this refrigeration apparatus, the compression mechanism (20, 30) (110, 120, 130, 140) includes four cylinder chambers (C1, C2, C3, C4), and the suction volume of the low-stage compression mechanism is Volume ratio changing means (7, 8) (107, 108) for changing the ratio of the suction volume of the high-stage compression mechanism is provided .

In this configuration , in the refrigeration apparatus in which the compression mechanism (20, 30) (110, 120, 130, 140) includes four cylinder chambers (C1, C2, C3, C4), the volume ratio changing means (7, 8 ) (107, 108), the operation is performed by changing the ratio of the suction volume of the low-stage compression mechanism to the suction volume of the high-stage compression mechanism.

In the first invention, the volume ratio changing means (7, 8) (107, 108) changes the connection relationship of the four cylinder chambers (C1, C2, C3, C4), thereby reducing the low-stage compression. The ratio of the suction volume of the mechanism and the high-stage compression mechanism (hereinafter, referred to as the suction volume ratio or simply the volume ratio) is changed .

In this configuration , for example, the operation can be performed by changing the connection relationship between the cylinder chamber used for the low-stage compression mechanism and the cylinder chamber used for the high-stage compression mechanism. That is, when two cylinder chambers are used for each of the low-stage side and the high-stage side, the cylinder volume of each compression chamber can be changed by changing the combination of the low-stage side cylinder chamber and the high-stage side cylinder chamber. Are different, the volume ratio can be adjusted according to the operating condition, three cylinder chambers are used on the lower stage side, one cylinder chamber is used on the higher stage side, and one cylinder chamber is installed on the lower stage side. The volume ratio can be adjusted according to the operating state by using three cylinder chambers on the higher stage.

In the first invention, the plurality of compression mechanisms (20, 30) include a first compression mechanism (20) and a second compression mechanism each having two cylinder chambers (C1, C2) (C3, C4). (30), and each compression mechanism (20, 30) includes a cylinder (21, 31) having an annular cylinder space, and an annular eccentric piston (22, 32) that performs eccentric rotational movement in the cylinder space. The inner cylinder chambers (C2, C4) are formed on the inner peripheral side of the annular eccentric piston (22, 32) in the cylinder space, and the outer cylinder chambers (C1, C3) are formed on the outer peripheral side .

In this configuration , the two compression mechanisms (20, 30) of the compressor (1) have two cylinder chambers (C1, C2) (C3) on the outer peripheral side and inner peripheral side of the annular piston (22, 32), respectively. , C4). A compression mechanism (20, 30) having an inner cylinder chamber (C2, C4) on the inner peripheral side of the annular piston (22, 32) and an outer cylinder chamber (C1, C3) on the outer peripheral side. The machine (1) can be operated by changing the ratio of the suction volume of the low-stage compression mechanism and the high-stage compression mechanism.

In the first invention, the volume ratio changing means (7) uses the second compression mechanism (30) by using both cylinder chambers (C1, C2) of the first compression mechanism (20) as a low-stage compression mechanism. ) Both cylinder chambers (C3, C4) used for the high-stage compression mechanism, and both cylinder chambers (C1, C2) of the first compression mechanism (20) and one cylinder chamber of the second compression mechanism (30). (C4) is used as a low-stage compression mechanism, and the second compression mechanism (30) is configured by a switching mechanism capable of switching between a state where the other cylinder chamber (C3) is used as a high-stage compression mechanism.

In this configuration, both cylinder chambers (C1, C2) of the first compression mechanism (20) are used as a low-stage compression mechanism, and both cylinder chambers (C3, C4) of the second compression mechanism (30) are subjected to high-stage compression. Second compression using the state used for the mechanism, and both cylinder chambers (C1, C2) of the first compression mechanism (20) and one cylinder chamber (C4) of the second compression mechanism (30) as the low-stage compression mechanism By switching the state where the other cylinder chamber (C3) of the mechanism (30) is used for the high-stage compression mechanism, the volume ratio can be adjusted in two operating states.

The second invention is different from the first invention in the specific configuration of the volume ratio changing means. Specifically, the volume ratio changing means (8) includes the first compression mechanism (20). A state in which both cylinder chambers (C1, C2) are used for the low-stage side compression mechanism and both cylinder chambers (C3, C4) of the second compression mechanism (30) are used for the high-stage side compression mechanism, and the first compression mechanism (20 ) And the other cylinder chamber (C2) of the first compression mechanism (20) using one cylinder chamber (C3) of the second compression mechanism (30) as the low-stage compression mechanism. The second compression mechanism (30) is configured by a switching mechanism capable of switching between a state in which the other cylinder chamber (C4) is used for the high-stage compression mechanism.

In the second invention, both cylinder chambers (C1, C2) of the first compression mechanism (20) are used as a low-stage compression mechanism, and both cylinder chambers (C3, C4) of the second compression mechanism (30) are made high. The first compression mechanism (20) uses one cylinder chamber (C1) and the second compression mechanism (30) one cylinder chamber (C3) as the low-stage compression mechanism. By switching between the state in which the other cylinder chamber (C2) of the first compression mechanism (20) and the other cylinder chamber (C4) of the second compression mechanism (30) are used for the high-stage compression mechanism, The volume ratio can be adjusted.

The third invention is characterized in that, in the first or second invention, the four cylinder chambers (C1, C2, C3, C4) are set to at least two types of suction volumes.

In this third invention , a compressor using a compression mechanism in which the inner cylinder chambers (C2, C4) on the inner peripheral side of the annular piston (22, 32) and the outer cylinder chambers (C1, C3) on the outer peripheral side are different in volume. , The inner cylinder chambers (C2, C4) of the two compression mechanisms (20, 30) are made the same size and the outer cylinder chambers (C1, C3) are made the same size, so that at least two types of suction A compression mechanism (20, 30) having four cylinder chambers (C1, C2, C3, C4) set to volume can be easily realized.

The fourth invention is characterized in that, in the first or second invention, the suction volumes of the four cylinder chambers (C1, C2, C3, C4) are all different.

In this fourth invention , the four cylinder chambers (C1, C2, C3, C4) all have different volumes, so the combination pattern of the cylinder chambers (C1, C2, C3, C4) for changing the volume ratio is changed. Can be maximized. And it becomes possible to respond to various operating conditions.

According to a fifth invention , in any one of the first invention to the fourth invention , the volume ratio changing means (7, 8) has a low-pressure refrigerant and an intermediate between the compression mechanisms (20, 30). It is characterized by comprising a switching valve for switching the flow path between the pressure refrigerant and the high pressure refrigerant.

In the fifth aspect of the invention , the volume ratio of the compressor (1) is adjusted according to different operating conditions by switching the flow paths of the low-pressure refrigerant, the intermediate-pressure refrigerant, and the high-pressure refrigerant by the switching valve (7, 8). Can do.

According to a sixth invention , in any one of the first to fifth inventions , the volume ratio changing means (7, 8) is configured so that the suction volume of the low-stage compression mechanism is The high-stage compression mechanism is configured to change the ratio of the suction volume.

In the sixth aspect of the invention , the ratio between the suction volume of the low-stage compression mechanism and the suction volume of the high-stage compression mechanism is adjusted with changes in the operating conditions.

The seventh invention provides a compressor (1) (100) in which a plurality of compression mechanisms (20, 30) (110, 120, 130, 140) are mechanically connected by a single drive shaft (53) (173). ) Is connected to the refrigerant circuit (60) (180) connected to the refrigeration apparatus for performing the two-stage compression refrigeration cycle.

In this refrigeration apparatus, the compression mechanism (20, 30) (110, 120, 130, 140) includes four cylinder chambers (C1, C2, C3, C4), and the suction volume of the low-stage compression mechanism is Volume ratio changing means (7, 8) (107, 108) for changing the ratio of the suction volume of the high-stage compression mechanism is provided.

In this configuration, in the refrigeration apparatus in which the compression mechanism (20, 30) (110, 120, 130, 140) includes four cylinder chambers (C1, C2, C3, C4), the volume ratio changing means (7, 8 ) (107, 108), the operation is performed by changing the ratio of the suction volume of the low-stage compression mechanism to the suction volume of the high-stage compression mechanism.

Further, according to the seventh aspect of the invention, the volume ratio changing means (7, 8) (107, 108) changes the connection relationship of the four cylinder chambers (C1, C2, C3, C4), thereby reducing the low-stage compression. The ratio between the suction volume of the mechanism and the high-stage compression mechanism is changed.

In this configuration, for example, the operation can be performed by changing the connection relationship between the cylinder chamber used for the low-stage compression mechanism and the cylinder chamber used for the high-stage compression mechanism. That is, when two cylinder chambers are used for each of the low-stage side and the high-stage side, the cylinder volume of each compression chamber can be changed by changing the combination of the low-stage side cylinder chamber and the high-stage side cylinder chamber. Are different, the volume ratio can be adjusted according to the operating condition, three cylinder chambers are used on the lower stage side, one cylinder chamber is used on the higher stage side, and one cylinder chamber is installed on the lower stage side. The volume ratio can be adjusted according to the operating state by using three cylinder chambers on the higher stage.

In the seventh invention, the plurality of compression mechanisms (110, 120, 130, 140) each include a first compression mechanism (110), a second compression mechanism (120), and a third compression mechanism each having one cylinder chamber. A compression mechanism (130) and a fourth compression mechanism (140), wherein each compression mechanism (110, 120, 130, 140) includes a cylinder (111, 121, 131, 141) having a cylindrical cylinder space; Eccentric pistons (112, 122, 132, 142) that perform eccentric rotational movement in the cylinder space are provided.

In this configuration, the four compression mechanisms (110, 120, 130, 140) included in the compressor (1) are respectively provided with a cylinder (111, 121, 131, 141) having a cylindrical cylinder space and the cylinder space. And eccentric pistons (112, 122, 132, 142) that perform eccentric rotational motion. In the compressor provided with the compression mechanism (110, 120, 130, 140) in which the eccentric piston (112, 122, 132, 142) rotates eccentrically in the cylinder space, the low-stage compression mechanism and the high-stage compression mechanism are provided. The operation can be performed by changing the ratio of the suction volume of the side compression mechanism.

Further, according to a seventh aspect of the present invention, the volume ratio changing means (107) uses the first compression mechanism (110) and the second compression mechanism (120) as the low-stage compression mechanism, and the third compression mechanism (130). Using the fourth compression mechanism (140) for the high-stage compression mechanism, and using the first compression mechanism (110), the second compression mechanism (120), and the third compression mechanism (130) for the low-stage compression mechanism. The fourth compression mechanism (140) is configured by a switching mechanism that can be switched to a state in which the fourth compression mechanism (140) is used for the high-stage compression mechanism.

In this configuration, the first compression mechanism (110) and the second compression mechanism (120) are used as the low-stage compression mechanism, and the third compression mechanism (130) and the fourth compression mechanism (140) are used as the high-stage compression mechanism. The first compression mechanism (110), the second compression mechanism (120), and the third compression mechanism (130) are used as a low-stage compression mechanism, and the fourth compression mechanism (140) is a high-stage compression mechanism. By switching the state to be used, the volume ratio can be adjusted in two operating states.

The eighth invention differs from the seventh invention in the specific configuration of the volume ratio changing means. Specifically, the volume ratio changing means (107) is different from the first compression mechanism (110) and the first ratio. A state in which the second compression mechanism (120) and the fourth compression mechanism (140) are used in the high-stage compression mechanism using the three-compression mechanism (130) as the low-stage compression mechanism, and the first compression mechanism (110) in the low-stage side It is constituted by a switching mechanism that can be switched to a state in which the second compression mechanism (120), the third compression mechanism (130), and the fourth compression mechanism (140) are used for the high-stage compression mechanism. Yes.

In the eighth invention , the first compression mechanism (110) and the third compression mechanism (130) are used as the low-stage compression mechanism, and the second compression mechanism (120) and the fourth compression mechanism (140) are arranged on the high-stage side. Using the first compression mechanism (110) as the low-stage compression mechanism, the second compression mechanism (120), the third compression mechanism (130), and the fourth compression mechanism (140) as the high-stage side By switching to the state used for the compression mechanism, the volume ratio can be adjusted in two operating states.

The ninth invention is different from the seventh and eighth inventions in the specific configuration of the volume ratio changing means. Specifically, the cylinder volume of at least one compression mechanism is the cylinder volume of another compression mechanism. Unlike the above, the volume ratio changing means (108) uses the first compression mechanism (110) and the second compression mechanism (120) as the low-stage compression mechanism, and the third compression mechanism (130) and the fourth compression mechanism ( 140) is used for the high-stage compression mechanism, and the second compression mechanism (120) and the fourth compression mechanism (120) are used by using the first compression mechanism (110) and the third compression mechanism (130) for the low-stage compression mechanism. 140) is configured by a switching mechanism that can be switched to a state to be used for the high- stage compression mechanism .

In the ninth aspect of the invention , the first compression mechanism (110) and the second compression mechanism (120) are replaced with the low-stage compression mechanism in a configuration in which the cylinder volume of at least one compression mechanism is different from the cylinder volume of the other compression mechanisms. The third compression mechanism (130) and the fourth compression mechanism (140) are used for the high-stage compression mechanism, and the first compression mechanism (110) and the third compression mechanism (130) are the low-stage compression mechanism. The volume ratio can be adjusted in two operating states by using the second compression mechanism (120) and the fourth compression mechanism (140) to switch to a state where they are used for the high-stage compression mechanism.

In a tenth aspect based on any one of the seventh aspect to the ninth aspect, the volume ratio changing means (107, 108) is configured so that the compression mechanisms (110, 120, 130, 140) It is characterized by comprising a switching valve that switches the flow path of the low-pressure refrigerant, intermediate-pressure refrigerant, and high-pressure refrigerant.

In the tenth aspect of the invention , the volume ratio of the compressor (1) is adjusted according to different operating conditions by switching the flow paths of the low-pressure refrigerant, the intermediate-pressure refrigerant, and the high-pressure refrigerant by the switching valves (107, 108). Can do.

In an eleventh aspect based on any one of the seventh aspect to the ninth aspect, the volume ratio changing means (107) is configured such that the suction volume and the high stage of the low-stage side compression mechanism are changed in accordance with a change in operating conditions. It is characterized by changing the ratio of the suction volume of the side compression mechanism.

In the eleventh aspect of the invention , the ratio between the suction volume of the low-stage compression mechanism and the suction volume of the high-stage compression mechanism is adjusted with changes in operating conditions.

In a twelfth aspect according to any one of the first to eleventh aspects, the refrigerant is carbon dioxide.

In the twelfth aspect of the present invention , the volume ratio can be adjusted in the compressor using carbon dioxide as the refrigerant.

  According to the present invention, in a refrigeration apparatus provided with a compressor (1) in which a plurality of compression mechanisms (20, 30) are mechanically connected by a single drive shaft (53) to compress refrigerant in two stages, The ratio of the suction volume of the stage side compression mechanism and the suction volume of the high stage side compression mechanism can be adjusted. Therefore, the operation with the optimum COP can be made possible. Further, if the volume ratio is changed, the compression torque is also changed, so that the fluctuation of the compression torque can be adjusted.

Further , according to the present invention , for example, the operation can be performed by changing the connection relationship between the cylinder chamber used for the low-stage side compression mechanism and the cylinder chamber used for the high-stage side compression mechanism. The operation at the optimum COP can be performed by adjusting the ratio between the volume and the suction volume of the high-stage compression mechanism.

Further , according to the present invention , the two compression mechanisms (20, 30) of the compressor (1) have two cylinder chambers (C1, C) on the outer peripheral side and inner peripheral side of the annular piston (22, 32), respectively. C2) In the configuration having (C3, C4), the operation at the optimum COP can be performed by adjusting the ratio between the suction volume of the low-stage compression mechanism and the suction volume of the high-stage compression mechanism.

  In addition, for example, in the two-stage compression mechanism, it is conceivable to adjust the suction volume ratio by unloading on the low stage side or the high stage side, but the present invention is different from such a structure and compresses the refrigerant from the middle. Therefore, smooth operation can be performed.

Further, according to the present invention, both cylinder chambers (C3, C4) of the second compression mechanism (30) are used by using both cylinder chambers (C1, C2) of the first compression mechanism (20) as the low-stage compression mechanism. The state used for the high-stage compression mechanism, and both cylinder chambers (C1, C2) of the first compression mechanism (20) and one cylinder chamber (C4) of the second compression mechanism (30) are used for the low-stage compression mechanism. The volume ratio can be adjusted in two operating states by switching the state where the other cylinder chamber (C3) of the second compression mechanism (30) is used for the high-stage compression mechanism. Correspondingly, the optimum COP can be operated.

According to the second invention, both cylinder chambers (C1, C2) of the first compression mechanism (20) are used as the low-stage compression mechanism, and both cylinder chambers (C3, C4) of the second compression mechanism (30) are used. Is used for the high-stage compression mechanism, and one cylinder chamber (C1) of the first compression mechanism (20) and one cylinder chamber (C3) of the second compression mechanism (30) are used for the low-stage compression mechanism. By switching between using the other cylinder chamber (C2) of the first compression mechanism (20) and the other cylinder chamber (C4) of the second compression mechanism (30) as the high-stage compression mechanism, two operations are performed. Since the volume ratio can be adjusted in the state, it is possible to perform the optimum COP operation corresponding to different operation conditions.

According to the third invention , the inner cylinder chambers (C2, C4) on the inner peripheral side of the annular piston (22, 32) and the outer cylinder chambers (C1, C3) on the outer peripheral side are different from each other. By setting the inner cylinder chambers (C2, C4) of the mechanism (20, 30) to the same size and the outer cylinder chambers (C1, C3) to the same size, at least two types of suction volumes were set. A compression mechanism (20, 30) having four cylinder chambers (C1, C2, C3, C4) can be easily realized.

According to the fourth aspect of the invention , if the axial lengths of the cylinder chambers (C1, C2, C3, C4) are adjusted, the suction volumes of the four cylinder chambers (C1, C2, C3, C4) are all made different. Is easy. And since all four cylinder chambers (C1, C2, C3, C4) have different volumes, the combination pattern of cylinder chambers (C1, C2, C3, C4) for changing the volume ratio is maximized, It is possible to perform optimum COP operation corresponding to various operation conditions .

According to the fifth aspect, the volume ratio of the compressor (1) can be adjusted according to different operating conditions by switching the flow paths of the low-pressure refrigerant, the intermediate-pressure refrigerant, and the high-pressure refrigerant by the switching valve. Therefore, the volume ratio of the compressor (1) can be adjusted with a simple configuration.

According to the sixth aspect of the invention , the ratio between the suction volume of the low-stage compression mechanism and the suction volume of the high-stage compression mechanism is adjusted as the operating condition changes. Therefore, it is possible to perform the optimum COP operation according to changes in the outside air temperature.

According to the seventh aspect of the invention , the four compression mechanisms (110, 120, 130, 140) of the compressor (1) include cylinders (111, 121, 131, 141) each having a cylindrical cylinder space. In a configuration having an eccentric piston (112, 122, 132, 142) that rotates eccentrically in the cylinder space, the ratio of the suction volume of the low-stage compression mechanism to the suction volume of the high-stage compression mechanism is adjusted. Thus, the operation with the optimum COP can be performed. In addition, it is conceivable to adjust the suction volume ratio by unloading on the low-stage side or the high-stage side in the two-stage compression mechanism. Because it does not become, you can perform a smooth operation.

According to the seventh invention , the first compression mechanism (110) and the second compression mechanism (120) are used as the low-stage compression mechanism, and the third compression mechanism (130) and the fourth compression mechanism (140) are used. The state used for the high-stage compression mechanism, and the fourth compression mechanism (140) using the first compression mechanism (110), the second compression mechanism (120), and the third compression mechanism (130) as the low-stage compression mechanism. By switching between the state used for the high-stage compression mechanism, the volume ratio can be adjusted in two operating states, so that the optimum COP operation can be performed corresponding to different operating conditions.

According to the eighth invention , the first compression mechanism (110) and the third compression mechanism (130) are used as the low-stage compression mechanism, and the second compression mechanism (120) and the fourth compression mechanism (140) are the high-stage. The first compression mechanism (110) as the low-stage compression mechanism, and the second compression mechanism (120), the third compression mechanism (130), and the fourth compression mechanism (140) as the high-stage. By switching to the state used for the side compression mechanism, the volume ratio can be adjusted in two operating states, so that the optimum COP operation can be performed corresponding to different operating conditions.

According to the ninth aspect, in the configuration in which the cylinder volume of at least one compression mechanism is different from the cylinder volume of the other compression mechanism, the first compression mechanism (110) and the second compression mechanism (120) are replaced with the low-stage compression mechanism. The third compression mechanism (130) and the fourth compression mechanism (140) are used for the high-stage compression mechanism, and the first compression mechanism (110) and the third compression mechanism (130) are the low-stage compression mechanism. By switching between the second compression mechanism (120) and the fourth compression mechanism (140) used for the high-stage compression mechanism, the volume ratio can be adjusted in the two operation states. It is possible to operate the optimum COP corresponding to the conditions .

According to the tenth aspect, the volume ratio of the compressor (1) can be adjusted according to different operating conditions by switching the flow path of the low-pressure refrigerant, the intermediate-pressure refrigerant, and the high-pressure refrigerant by the switching valve. Therefore, the volume ratio of the compressor (1) can be adjusted with a simple configuration.

According to the eleventh aspect of the invention , the ratio between the suction volume of the low-stage compression mechanism and the suction volume of the high-stage compression mechanism is adjusted with changes in operating conditions. Therefore, it is possible to perform the optimum COP operation according to changes in the outside air temperature.

According to the twelfth aspect of the invention , since the refrigerant is carbon dioxide, the effect of the two-stage compression is significant compared to other refrigerants, and the COP improvement effect is also increased.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

《 Technical prerequisite for invention》
The prerequisite technology of the present invention will be described.

FIG. 1 is a longitudinal sectional view of a compressor (1) used in a refrigeration apparatus (air conditioning apparatus) according to this prerequisite technology , FIG. 2 is a transverse sectional view of a compression mechanism (first compression mechanism), and FIG. 3 is a compression mechanism. It is an operation state figure of the (first compression mechanism). FIG. 4 is a refrigerant circuit diagram showing a first operation state of the air conditioner, and FIG. 5 is a refrigerant circuit diagram showing a second operation state. The compressor (1) is used for compressing the refrigerant sucked from the evaporator and discharging it to the condenser in the refrigerant circuit of the air conditioner.

<Compressor configuration>
First, the configuration of the compressor (1) will be described. The compressor (1) is a rotary compressor, and includes a first compression mechanism (20) and a second compression mechanism (30) mechanically connected by a single drive shaft (53), and a refrigerant (operation The carbon dioxide, which is a fluid, is compressed in two stages. That is, the first compression mechanism (20) and the second compression mechanism (30) constitute a two-stage compression mechanism. In addition, since the cross-sectional view and the operation state diagram of the second compression mechanism (30) are substantially the same as the first compression mechanism (20), the reference numerals of the second compression mechanism (30) are entered in FIG. Details are omitted. Further, the first compression mechanism (20) and the second compression mechanism (30) are arranged so that the phases are different by 180 °.

As shown in FIG. 1, in the compressor (1), a first compression mechanism (20), a second compression mechanism (30), and an electric motor (drive mechanism) (50) are accommodated in a casing (10). It is a thing and is comprised by the completely sealed type. In this base technology , the first compression mechanism (20) is a low-stage compression mechanism, and the second compression mechanism (30) is a high-stage compression mechanism.

  The casing (10) includes a cylindrical body (11), an upper end panel (12) fixed to the upper end of the body (11), and a lower end panel fixed to the lower end of the body (11). (13). The first suction port (14-1) and the first discharge port (15-1) are located below the body (11) at the first outer cylinder chamber and the first inner cylinder of the first compression mechanism (20). It is provided as a suction port and a discharge port for the chamber (which will be described later). The body (11) is provided with a second suction port (14-2) as a suction port of the second compression mechanism (30) at a position slightly above the first suction port (14-1). ing. The second suction port (14-2) is composed of a second a suction port (14-2a) for a second outer cylinder chamber and a second b suction port (14-2b) for a second inner cylinder chamber, which will be described later. It is configured. Two second discharge ports (15-2) are provided one by one on the body (11) and the upper end plate (12). A second a discharge port (15-2a) for the outer cylinder chamber is provided at a position below the center of the body (11), and a second b discharge for the inner cylinder chamber is provided at a position above the body (11). Port (15-2b) is provided.

  The configurations of the suction port (14a, 14b) and the discharge port (15a, 15b) can be summarized as follows. That is, the first suction port (14-1) is constituted by one suction port for sucking the refrigerant into both the first outer cylinder chamber (C1) and the first inner cylinder chamber (C2). The first discharge port (15-1) is composed of one discharge port for discharging refrigerant from both the first outer cylinder chamber (C1) and the first inner cylinder chamber (C2). The second suction port (14-2) sucks the refrigerant into the second outer cylinder chamber (C3), the second a suction port (14-2a) for sucking the refrigerant into the second outer cylinder chamber (C3), and the second inner cylinder chamber (C4). It is comprised by the 2b suction port (14-2b) for this. The second discharge port (15-2) includes a second a discharge port (15-2a) for discharging refrigerant from the second outer cylinder chamber (C3), and a casing ( 10) It is comprised from the 2b discharge port (15-2b) for discharging a refrigerant | coolant through the space in.

  The first compression mechanism (20) and the second compression mechanism (30) are stacked in two upper and lower stages, and are configured between a front head (16) and a rear head (17) fixed to the casing (10). Yes. The second compression mechanism (30) is disposed on the electric motor side (upper side in FIG. 1), and the first compression mechanism (20) is disposed on the bottom side (lower side in FIG. 1) of the casing (10). A middle plate (19) is provided between the front head (16) and the rear head (17).

  As shown in FIG. 2, the first compression mechanism (20) includes a first cylinder (21) having an annular first cylinder chamber (C1, C2), and the first cylinder chamber (C1, C2). The first annular piston (22) arranged and the first cylinder chamber (C1, C2) as shown in FIG. 2 and FIG. 3 are a high pressure chamber (compression chamber) (C1-Hp, C2-Hp) as the first chamber. ) And a first blade (23) partitioned into a low pressure chamber (suction chamber) (C1-Lp, C2-Lp) which is a second chamber.

  On the other hand, the second compression mechanism (30) is turned upside down with respect to the first compression mechanism (20). The second compression mechanism (30) includes a second cylinder (31) having an annular second cylinder chamber (C3, C4), and a second annular piston disposed in the second cylinder chamber (C3, C4). (32) and a second blade (33) that partitions the second cylinder chamber (C3, C4) into a high pressure chamber (not shown) as a first chamber and a low pressure chamber (not shown) as a second chamber And have.

In this base technology , the front head (16) constitutes the second cylinder (31), and the rear head (17) constitutes the first cylinder (21). In the base technology , the first cylinder (21) having the first cylinder chambers (C1, C2) and the second cylinder (31) having the second cylinder chambers (C3, C4) are fixed on the first annular side. The piston (22) and the second annular piston (32) are movable sides. The first annular piston (22) is eccentrically rotated with respect to the first cylinder (21), and the second annular piston (32) is eccentrically rotated with respect to the second cylinder (31). Has been.

The electric motor (50) includes a stator (51) and a rotor (52). The stator (51) is disposed above the second compression mechanism (30), and is fixed to the body (11) of the casing (10). A drive shaft (crank shaft) (53) is connected to the rotor (52), and the drive shaft (53) is configured to rotate together with the rotor (52). The drive shaft (53) passes through the first cylinder chamber (C1, C2) and the second cylinder chamber (C3, C4) in the vertical direction. The compressor (1) generally employs an oil supply structure that uses an oil supply passage extending in the axial direction inside the drive shaft (53), but the oil supply structure is omitted in this presupposed technology .

  The drive shaft (53) has a first eccentric portion (53a) formed in a portion located in the first cylinder chamber (C1, C2), and a portion located in the second cylinder chamber (C3, C4). The second eccentric portion (53b) is formed in the upper portion. The first eccentric portion (53a) is formed with a larger diameter than the upper and lower main shaft portions of the first eccentric portion (53a), and is eccentric by a predetermined amount from the axis of the drive shaft (53). The second eccentric portion (53b) is formed to have the same diameter as the first eccentric portion (53a), and is eccentric from the axis of the drive shaft (53) by the same amount as the first eccentric portion (53a). The first eccentric portion (53a) and the second eccentric portion (53b) are 180 ° out of phase with each other about the axis of the drive shaft (53).

  The first annular piston (22) is an integrally formed member, and a first bearing portion (22a) slidably fitted to a first eccentric portion (53a) of the drive shaft (53). A first annular piston body (22b) positioned concentrically with the first bearing part (22a) on the outer peripheral side of the first bearing part (22a), a first bearing part (22a) and a first annular piston body A first piston-side end plate (22c) connecting the portion (22b), and the first annular piston main body portion (22b) is formed in a C-shape with a part of the annular ring divided (FIG. 2). reference).

  Similarly to the first annular piston (22), the second annular piston (32) is an integrally formed member, and is slidable on the second eccentric portion (53b) of the drive shaft (53). A second bearing portion (32a) fitted to the second bearing portion (32a), a second annular piston main body portion (32b) positioned concentrically with the second bearing portion (32a) on the outer peripheral side of the second bearing portion (32a), 2 A second piston-side end plate (32c) that connects the bearing portion (32a) and the second annular piston main body portion (32b) is provided, and the second annular piston main body portion (32b) is partly cut off from the ring. It is formed in a C-shape (see FIG. 2).

  The first cylinder (21) includes a first inner cylinder part (21b) positioned concentrically with the drive shaft (53) between the first bearing part (22a) and the first annular piston body part (22b). A first outer cylinder portion (21a) concentric with the first inner cylinder portion (21b) on the outer peripheral side of the first annular piston main body portion (22b), a first inner cylinder portion (21b) and a first outer side A first cylinder side end plate (21c) connecting the cylinder part (21a) is provided.

  The second cylinder (31) includes a second inner cylinder part (31b) positioned concentrically with the drive shaft (53) between the second bearing part (32a) and the second annular piston body part (32b). A second outer cylinder portion (31a) concentrically with the second inner cylinder portion (31b) on the outer peripheral side of the second annular piston body portion (32b), a second inner cylinder portion (31b), and a second outer side. A second cylinder-side end plate (31c) that connects the cylinder portion (31a) is provided.

The front head (16) and the rear head (17) are formed with bearing portions (16a, 17a) for supporting the drive shaft (53), respectively. In the compressor (1) of the base technology, the drive shaft (53) penetrates the first cylinder chamber (C1, C2) and the second cylinder chamber (C3, C4) in the vertical direction, and the first eccentric portion (53a) and the second eccentric portion (53b) have a through-shaft structure in which both axial portions of the second eccentric portion (53b) are held by the casing (10) via the bearing portions (16a, 17a).

  Next, the internal structure of the first and second compression mechanisms (20, 30) will be described. The first and second compression mechanisms (20, 30) have an annular piston (22, 32) for changing the cylinder volume. The first compression mechanism (20) will be described as a representative example since the configuration is substantially the same except for the axial length of the cylinder and the corresponding axial length of the cylinder (21, 31). .

  As shown in FIG. 2, the first compression mechanism (20) is capable of swinging the first annular piston (22) with respect to the first blade (23) at the dividing position of the first annular piston (22). A first swing bush (27) is provided as a connecting member to be connected to. The first blade (23) is arranged on the inner circumferential wall surface of the first cylinder chamber (C1, C2) (the outer periphery of the first inner cylinder portion (21b)) on the radial line of the first cylinder chamber (C1, C2). Surface) to the outer peripheral wall surface (inner peripheral surface of the first outer cylinder portion (21a)), and is configured to extend through the dividing portion of the first annular piston (22). (21a) and the first inner cylinder part (21b). The first blade (23) may be formed integrally with the first outer cylinder part (21a) and the first inner cylinder part (21b), or separate members may be provided on both cylinder parts (21a, 21b). It may be attached. The example shown in FIG. 2 is an example in which another member is fixed to both cylinder parts (21a, 21b).

  The inner peripheral surface of the first outer cylinder portion (21a) and the outer peripheral surface of the first inner cylinder portion (21b) are cylindrical surfaces arranged on the same center, and the first cylinder chambers (C1, C2) between them. ) Is formed. The first annular piston (22) has an outer peripheral surface having a smaller diameter than an inner peripheral surface of the first outer cylinder portion (21a) and an inner peripheral surface having a larger diameter than an outer peripheral surface of the first inner cylinder portion (21b). Is formed. Thus, a first outer cylinder chamber (C1) is formed between the outer peripheral surface of the first annular piston (22) and the inner peripheral surface of the first outer cylinder portion (21a), and the first annular piston (22) A first inner cylinder chamber (C2) is formed between the inner peripheral surface of the first inner cylinder portion and the outer peripheral surface of the first inner cylinder portion (21b). That is, the compressor (1) includes a first compression mechanism (20) and a second compression mechanism (30) each having two compression chambers (C1, C2) (C3, C4). 20, 30) includes a cylinder (21, 31) having an annular cylinder space and an annular piston (22, 32) that performs eccentric rotational movement in the cylinder space, and the annular piston ( 22 and 32), inner cylinder chambers (C2, C4) are formed on the inner peripheral side, and outer cylinder chambers (C1, C3) are formed on the outer peripheral side.

  Specifically, the first outer cylinder chamber is located between the first cylinder side end plate (21c), the first piston side end plate (22c), the first outer cylinder portion (21a), and the first annular piston body portion (22b). (C1) is formed, the first inner side between the first cylinder side end plate (21c), the first piston side end plate (22c), the first inner cylinder part (21b) and the first annular piston body part (22b). A cylinder chamber (C2) is formed. Further, between the first cylinder side end plate (21c), the first piston side end plate (22c), the first bearing portion (22a) of the first annular piston (22), and the first inner cylinder portion (21b), An operation space (25) for allowing the eccentric rotation operation of the first bearing portion (22a) is formed on the inner peripheral side of the first inner cylinder portion (21b) (see FIG. 2).

  In the first annular piston (22) and the first cylinder (21), the outer peripheral surface of the first annular piston (22) and the inner peripheral surface of the first outer cylinder part (21a) are substantially in contact at one point ( Strictly speaking, there is a gap on the order of microns, but leakage of refrigerant in the gap does not cause a problem), and at a position that is 180 ° out of phase with the contact point, the inner circumferential surface of the first annular piston (22) One outer cylinder surface (21b) is substantially in contact with the outer peripheral surface at one point.

  The first swing bush (27) includes a discharge side bush (27A) located on the high pressure chamber (intermediate pressure chamber) (C1-Hp, C2-Hp) side with respect to the first blade (23), and a first It consists of a suction side bush (27B) located on the low pressure chamber (C1-Lp, C2-Lp) side with respect to the blade (23). The discharge-side bush (27A) and the suction-side bush (27B) are both substantially semicircular in cross section and formed in the same shape, and are arranged so that the flat surfaces face each other. And the space between the opposing surfaces of both bushes (27A, 27B) constitutes a blade groove (28).

  The first blade (23) is inserted into the blade groove (28), and the flat surface of the first swing bush (27A, 27B) substantially comes into surface contact with the first blade (23). The arc-shaped outer peripheral surface of (27A, 27B) is substantially in surface contact with the first annular piston (22). The first swing bushes (27A, 27B) are configured to advance and retreat in the surface direction of the first blade (23) with the first blade (23) sandwiched between the blade grooves (28). The first swing bush (27A, 27B) is configured such that the first annular piston (22) swings with respect to the first blade (23). Therefore, in the first swing bush (27), the first annular piston (22) swings with respect to the first blade (23) with the center point of the first swing bush (27) as the swing center. The first annular piston (22) is configured to be able to advance and retract in the surface direction of the first blade (23) with respect to the first blade (23).

In this base technology , an example in which both bushes (27A, 27B) are separated from each other has been described. However, both bushes (27A, 27B) may be integrated with each other by being partially connected.

  In the above configuration, when the drive shaft (53) rotates, the first annular piston (22) moves the first swing bush while the first swing bush (27) advances and retreats along the first blade (23). Swing around the center point of (27). When the drive shaft (53) rotates, the second annular piston (32) also swings about the center point of the second swing bush (37) as in the first annular piston (22). To do.

  By this swinging operation, the first contact point between the first annular piston (22) and the first cylinder (21) is moved in order from FIG. 3 (A) to FIG. 3 (H). On the other hand, the second contact point between the second annular piston (32) and the second cylinder (31) is shifted by 180 ° around the axis of the drive shaft (53) with respect to the first contact point. That is, when the operating state of the first compression mechanism (20) is FIG. 3 (A) when viewed from above the drive shaft (53), the operating state of the second compression mechanism (30) is FIG. 3 (E). .

  FIG. 3 is a diagram showing the operating state of the first compression mechanism (20), and the first annular piston (22) is rotated clockwise at 45 ° intervals from FIG. 3 (A) to FIG. 3 (H). It shows a state of moving to. At this time, the first annular piston (22) revolves around the drive shaft (53) but does not rotate.

  The first compression mechanism (20) has the first suction port (14-1) for sucking low-pressure refrigerant and the first discharge port (15-1) for discharging intermediate-pressure refrigerant. The rear head (17) is formed with a first suction port (41a) to which the first suction port (14-1) is connected. The first suction port (41a) of the rear head (17) communicates with the low pressure chambers of the first outer cylinder chamber (C1) and the first inner cylinder chamber (C2) via the first introduction passage (42a). Yes. The first suction port (14-1) is fixed to the rear head (17) and communicates with the cylinder chambers (C1, C2) of the first compression mechanism (20).

  The rear head (17) has an intermediate discharge space (17b) communicating with the cylinder chambers (C1, C2) of the first compression mechanism (20). The intermediate pressure refrigerant compressed by the first compression mechanism (20) includes an outer discharge port (45a) and an inner discharge port (46a) shown in FIG. 2, and a discharge valve (not shown; discharge valve presser) that opens and closes them. (47) is discharged to the intermediate discharge space (17b) through the drawing. The first discharge port (15-1) passing through the body (11) of the casing (10) is fixed to the rear head (17), and the first discharge port (15-1) is connected to the inner end. The opening opens to the intermediate discharge space (17b) of the rear head (17), and the outer end is connected to an intermediate pressure refrigerant pipe (not shown in FIG. 1) of the refrigerant circuit.

  The second compression mechanism (30) has the second suction port (14-2) for sucking the intermediate pressure refrigerant. The second suction port (14-2) includes a second a suction port (14-2a) for the outer cylinder chamber (C3) and a second b suction port (14-2b) for the inner cylinder chamber (C4). ing. The front head (16) is formed so that a 2a suction port (41b-1) to which the 2a suction port (14-2a) is connected communicates with the low pressure chamber of the second outer cylinder chamber (C3). The second b suction port (41b-2) to which the second b suction port (14-2b) is connected is formed to communicate with the low pressure chamber of the second inner cylinder chamber (C4). The second suction port (14-2) is fixed to the front head (16) and communicates with the cylinder chambers (C3, C4) of the second compression mechanism (30).

  The high-pressure refrigerant compressed in the cylinder chambers (C3, C4) of the second compression mechanism (30) is discharged from the discharge ports (45b, 46b) of the second outer cylinder chamber (C3) and the second inner cylinder chamber (C4), and It discharges to discharge space (49a, 49b) via a discharge valve (not shown; discharge valve retainer (48) is shown). The second discharge port (15-2a) for the outer cylinder chamber (C3) is connected to the outer discharge space (49a). The inner discharge space (49b) communicates with the space in the casing (10). And the discharge gas in a casing (10) is discharged to the high pressure gas pipe of a refrigerant circuit from the 2b discharge port (15-2b) provided in the upper part of the casing (10).

In this base technology , a first compression mechanism (20) and a second compression mechanism (30) constitute a two-stage compression mechanism, and the cylinder volume of the second compression mechanism (30), which is the higher stage side, is lower. It is smaller than the cylinder volume of a certain first compression mechanism (20). Therefore, the axial length of the second annular piston body (32b) is smaller than the axial length of the first annular piston body (22b). With the above configuration, the volumes of the four cylinder chambers are all different in this prerequisite technology .

<Configuration of refrigerant circuit>
The refrigerant circuit (60) of this air conditioner performs a refrigeration cycle by compressing carbon dioxide, which is a refrigerant, to a supercritical pressure with the compressor (1). As shown in FIG. Machine (1), gas cooler (2), evaporator (3), gas-liquid separator (4), first expansion valve (5), and second expansion valve (6) . The refrigerant circuit is provided with two three-way valves (switching valves) (7).

  The first suction port (14-1) of the compressor (1) is connected to the gas side end of the evaporator (3) via the first suction pipe (61). The first discharge port (15-1) of the compressor (1) is connected to the refrigerant gas outlet (4a) of the gas-liquid separator (4) via the first discharge pipe (63). The outlet (4c) of the gas-liquid separator (4) is connected to the liquid side end of the evaporator (3) via a liquid pipe (66) provided with a second expansion valve (6) in the middle. Yes.

  A second b discharge pipe (64b) is connected to the second b discharge port (15-2b) of the compressor (1). The second b discharge pipe (64b) is connected to the inlet (4b) of the gas-liquid separator (4) via the gas cooler (2) and the first expansion valve (5).

  The 2a discharge port (15-2a) of the compressor is connected to the 1st port (P1) of the 1st three way valve (7a) via 2a discharge pipe (64a). A connecting pipe (67a) is connected to the second port (P2) of the first three-way valve (7a), and this connecting pipe (67a) joins the upstream side of the gas cooler (2) in the second b discharge pipe (64b). ing. The third port (P3) of the first three-way valve (7a) is connected to the second port (P2) of the second three-way valve (7b) via an intermediate suction pipe (65) having a muffler (9). .

  The first discharge pipe (63) is branched into the branch pipe (68) on the way. The branch pipe (68) is connected to the second a suction port (14-2a) of the second compression mechanism (30) via a second a suction pipe (62a) having a muffler (9). 1) also has an injection tube function for injecting intermediate pressure refrigerant. The third port (P3) of the second three-way valve (7b) is connected to the downstream side of the muffler (9) in the 2a suction pipe (62a). The first port (P1) of the second three-way valve (7b) is connected to the second b suction port (14-2b) of the second compression mechanism (30) via the second b suction pipe (62b).

  Each of the three-way valves (7) has a first position where the first port (P1) and the second port (P2) communicate with each other, and a second position where the first port (P1) and the third port (P3) communicate with each other. It can be switched.

  The three-way valve (7) is a switching mechanism (volume ratio changing means) that switches the flow path of the low-pressure refrigerant, the intermediate-pressure refrigerant, and the high-pressure refrigerant with respect to the compression mechanisms (20, 30). By changing the connection relationship in the refrigerant circuit (60) of (C1, C2, C3, C4), the suction volume of the low-stage compression mechanism (20) and the suction volume of the high-stage compression mechanism (30) It is configured to change the ratio. That is, the switching mechanism (7) includes the cylinder chamber used for the low-stage compression mechanism (20) and the cylinder used for the high-stage compression mechanism (30) among the four cylinder chambers (C1, C2, C3, C4). It is configured to switch chambers.

  The switching mechanism (7) has an inner cylinder of the second compression mechanism (30) with respect to the first compression mechanism (20) on the lower stage side and the second compression mechanism (30) on the higher stage side. The chamber (C4) and the outer cylinder chamber (C3) are configured to be switchable between a state of being connected in parallel and a state of being connected in series.

  The switching mechanism (volume ratio changing means) (7) is configured to change the ratio of the suction volume of the low-stage compression mechanism and the suction volume of the high-stage compression mechanism in accordance with a change in operating conditions. Yes.

-Driving action-
<Operation of compressor>
Next, the operation of the compressor (1) will be described. Here, the operations of the first and second compression mechanisms (20, 30) are performed in a state where the phases are different from each other by 180 °.

  When the electric motor (50) is activated, the rotation of the rotor (52) is transmitted to the first annular piston (22) via the drive shaft (53) in the first compression mechanism (20) that is the low-stage compression mechanism. . Then, the first swing bush (27A, 27B) reciprocates (advances and retracts) along the first blade (23), and the first annular piston (22) and the first swing bush (27A, 27B). ) Integrally move to swing the first blade (23). At that time, the first swing bushes (27A, 27B) substantially make surface contact with the first annular piston (22) and the first blade (23). Then, the first annular piston (22) revolves while swinging relative to the first outer cylinder part (21a) and the first inner cylinder part (21b), and the first compression mechanism (20) performs a predetermined compression operation. Do.

  Specifically, in the first outer cylinder chamber (C1), the volume of the low pressure chamber (C1-Lp) is almost the minimum in the state of FIG. 3B, and from here the drive shaft (53) rotates clockwise in the figure. When the volume of the low-pressure chamber (C1-Lp) increases as it rotates and changes to the state of FIG. 3 (C) to FIG. 3 (A), the refrigerant flows into the first suction port (14-1 ) Through the low pressure chamber (C1-Lp).

  When the drive shaft (53) makes one revolution and returns to the state of FIG. 3 (B), the suction of the refrigerant into the low pressure chamber (C1-Lp) is completed. This low-pressure chamber (C1-Lp) is now a high-pressure chamber (intermediate pressure chamber) (C1-Hp) in which refrigerant is compressed, and a new low-pressure chamber (C1-Lp) is separated from the first blade (23). Is formed. When the drive shaft (53) further rotates, the suction of the refrigerant is repeated in the low pressure chamber (C1-Lp), while the volume of the high pressure chamber (intermediate pressure chamber) (C1-Hp) decreases, and the high pressure chamber (intermediate pressure chamber (C1-Lp)) The refrigerant is compressed in the pressure chamber (C1-Hp). When the pressure in the high pressure chamber (intermediate pressure chamber) (C1-Hp) reaches a preset value and the differential pressure from the intermediate discharge space (17b) reaches the set value, the high pressure chamber (intermediate pressure chamber) (C1-Hp) The intermediate pressure refrigerant opens the discharge valve, and the intermediate pressure refrigerant flows out of the casing (10) from the intermediate discharge space (17b) through the first discharge port (15-1).

  In the first inner cylinder chamber (C2), the volume of the low-pressure chamber (C2-Lp) is almost the minimum in the state of FIG. 3 (F), and the drive shaft (53) rotates clockwise from here. When the volume of the low-pressure chamber (C2-Lp) increases as the state changes from 3 (G) to FIG. 3 (E), the refrigerant flows into the first suction port (14-1) and the first The air is sucked into the low pressure chamber (C2-Lp) of the first inner cylinder chamber (C2) through the introduction passage (42a).

  When the drive shaft (53) makes one revolution and again enters the state of FIG. 3 (F), the suction of the refrigerant into the low pressure chamber (C2-Lp) is completed. This low-pressure chamber (C2-Lp) is now a high-pressure chamber (intermediate pressure chamber) (C1-Hp) where the refrigerant is compressed, and a new low-pressure chamber (C2-Lp) across the first blade (23). Is formed. When the drive shaft (53) further rotates, the suction of the refrigerant is repeated in the low pressure chamber (C2-Lp), while the volume of the high pressure chamber (intermediate pressure chamber) (C2-Hp) decreases, and the high pressure chamber (intermediate pressure chamber (C2-Lp)) The refrigerant is compressed in the pressure chamber (C2-Hp). When the pressure in the high pressure chamber (intermediate pressure chamber) (C2-Hp) reaches a set value and the differential pressure from the intermediate discharge space (17b) reaches the set value, the high pressure chamber (intermediate pressure chamber) (C2-Hp) The intermediate pressure refrigerant opens the discharge valve, and the intermediate pressure refrigerant flows out of the casing (10) from the intermediate discharge space (17b) through the first discharge port (15-1).

  In the first outer cylinder chamber (C1), refrigerant discharge is started approximately at the timing shown in FIG. 3E, and in the first inner cylinder chamber (C2), discharge is started approximately at the timing shown in FIG. That is, the discharge timing differs by approximately 180 ° between the first outer cylinder chamber (C1) and the first inner cylinder chamber (C2).

  In the second compression mechanism (30), the rotation of the rotor (52) is transmitted to the second annular piston (32) via the drive shaft (53). Then, the second swinging bush (37) reciprocates (advances and retracts) along the second blade (33), and the second annular piston (32) and the second swinging bush (37) are integrated. Then, the second blade (33) is swung. At that time, the second rocking bush (37) substantially makes surface contact with the second annular piston (32) and the second blade (33). The second annular piston (32) revolves while swinging relative to the second outer cylinder part (31a) and the second inner cylinder part (31b), and the second compression mechanism (30) performs a predetermined compression operation. Do.

  The compression operation is substantially the same as the compression operation of the first compression mechanism (20) except that the pressure is different, and the refrigerant is compressed in the cylinder chambers (C3, C4). In the second inner cylinder chamber (C4) and the second outer cylinder chamber (C3), when the pressure in the high pressure chamber (C3-Hp, C4-Hp) reaches a predetermined value, the discharge valve opens due to the refrigerant pressure, and the refrigerant It flows out of the compression chamber through the discharge port (45b, 46b) and the discharge valve of the head (16). The refrigerant in the outer second cylinder chamber (C3) flows out of the casing (10) through the second a discharge port (15-2a), and the refrigerant in the inner second cylinder chamber (C4) is filled in the casing (10). Later, it flows out of the casing through the second b discharge port (15-2b).

<Operation of air conditioner>
In this air conditioner, the first operating state shown in FIG. 4 and the second operating state shown in FIG. 5 can be switched in accordance with changes in operating conditions. In the following description, it is assumed that the operation is a cooling operation.

  In the first operating state shown in FIG. 4, the first three-way valve (7a) is set to the first position, and the second three-way valve (7b) is set to the second position. When the compressor is started in this state, the low-pressure gas refrigerant evaporated by exchanging heat with air in the evaporator (3) is sucked into the first compression mechanism (20) from the first suction port (14-1) of the compressor. The intermediate pressure refrigerant is compressed in the outer first cylinder chamber (C1) and the inner first cylinder chamber (C2). The intermediate pressure refrigerant merges with the refrigerant from the gas-liquid separator (4) and flows into the branch pipe (68).

  The intermediate pressure refrigerant flowing through the branch pipe (68) is divided into the 2a suction pipe (62a) and the 2b suction pipe (62b), and the second outer cylinder chamber (C3) and the second 2nd suction mechanism (30). Inhaled into the inner cylinder chamber (C4). The intermediate pressure refrigerant sucked into the second compression mechanism (30) is compressed into the high pressure refrigerant in the second outer cylinder chamber (C3) and the second inner cylinder chamber (C4). Of the high-pressure refrigerant, the refrigerant that has flowed out of the second outer cylinder chamber (C3) is discharged from the second-a discharge port (15-2a). The refrigerant flowing out from the second inner cylinder chamber (C4) is discharged from the second b discharge port (15-2b) after filling the casing (10). The refrigerant discharged from the second a discharge port (15-2a) and the refrigerant discharged from the second b discharge port (15-2b) merge and flow into the gas cooler (2). The refrigerant dissipates heat to the outdoor air by the gas cooler (2), is reduced to an intermediate pressure by the first expansion valve (5), and flows into the gas-liquid separator (4). The liquid refrigerant separated by the gas-liquid separator (4) flows out of the gas-liquid separator (4), is reduced to a low pressure by the second expansion valve (6), is evaporated by the evaporator (3), Inhaled into one compression mechanism (20).

  In the second operating state shown in FIG. 5, the first three-way valve (7a) is set to the second position, and the second three-way valve (7b) is set to the first position. When the compressor is started in this state, the low-pressure gas refrigerant evaporated by heat exchange with the air in the evaporator (3) is sucked into the first compression mechanism (20) from the first suction port (14-1), The refrigerant is compressed in the one cylinder chamber (C1) and the inner first cylinder chamber (C2) to become an intermediate pressure refrigerant (this pressure is referred to as a first intermediate pressure). The first intermediate pressure refrigerant merges with the refrigerant from the gas-liquid separator (4) and flows into the branch pipe (68).

  The first intermediate pressure refrigerant flowing through the branch pipe (68) is sucked into the second outer cylinder chamber (C3) of the second compression mechanism (30) from the second a suction pipe (62a). The first intermediate pressure refrigerant sucked into the second outer cylinder chamber (C3) of the second compression mechanism (30) is pressurized in the second outer cylinder chamber (C3) (this pressure is referred to as a second intermediate pressure). . The refrigerant whose pressure has been increased to the second intermediate pressure is discharged from the second-a discharge port (15-2a). The refrigerant flowing out from the second a discharge port (15-2a) passes through the first three-way valve (7a) and the second three-way valve (7b), and then from the second b suction port (14-2b) to the second compression mechanism ( 30) into the second inner cylinder chamber (C4). In the second inner cylinder chamber (C4), the refrigerant is further compressed to a high pressure and discharged into the high pressure space in the casing (10). The high-pressure refrigerant filled in the casing (10) is discharged from the second b discharge port (15-2b) and flows into the gas cooler (2). The refrigerant radiates heat to the outdoor air by the gas cooler (2), is then reduced to the first intermediate pressure by the first expansion valve (5), and flows into the gas-liquid separator (4). The liquid refrigerant separated by the gas-liquid separator (4) flows out of the gas-liquid separator (4), is reduced to a low pressure by the second expansion valve (6), is evaporated by the evaporator (3), Inhaled into one compression mechanism (20).

−Effects of prerequisite technologies−
According to this base technology , the suction volume to the first compression mechanism (20) is the same in the first operating state and the second operating state, but in the first operating state, the second outer cylinder chamber (C3 ) And the second inner cylinder chamber (C4), the intermediate pressure refrigerant is sucked into only the second outer cylinder chamber (C3) in the second operating state. That is, the first operating state and the second operating state have the same low suction volume, while the high operating suction volume is smaller in the second operating state than in the first operating state. .

As described above, in the base technology , the first operating state using the two cylinder chambers (C3, C4) of the second compression mechanism (30) in parallel and the second operating state used in series are switched. Therefore, in the compressor (1) in which the two compression mechanisms (20, 30) are mechanically connected to one shaft (53), the low-stage compression mechanism in the first operation state and the second operation state. The ratio of the suction volume of (20) and the suction volume of the higher stage compression mechanism (30) can be adjusted. Thus, by adjusting the ratio of the suction volume of the low-stage compression mechanism (20) and the suction volume of the high-stage compression mechanism (30) in the compressor (1) according to the operating conditions, the COP (coefficient of performance) ) Is possible. In addition, torque fluctuations associated with refrigerant compression can be adjusted.

Incidentally, for example, compression it is conceivable to adjust a suction volume ratio by unloading the low-stage or high-stage, in the base technology, the refrigerant unlike such a way in the two-stage compression mechanism Since it is not configured to perform, smooth operation can be performed.

-Modifications of the underlying technology-
6 to 10, the four cylinder chambers (C1, C2, C3, C4) of the first compression mechanism (20) and the second compression mechanism (30) are switched (recombined) in series and in parallel. The switching pattern in the case is illustrated. Each figure is a cross-sectional view of the main part.

  In these examples, the first suction port (14-1) includes a first a suction port (14-1a) for sucking refrigerant into the first outer cylinder chamber (C1), and a first inner cylinder chamber (C2). It is constituted by a 1b suction port (14-1b) for sucking refrigerant into the tank. The first discharge port (15-1) discharges refrigerant from the first a discharge port (15-1a) for discharging refrigerant from the first outer cylinder chamber (C1) and from the first inner cylinder chamber (C2). 1b discharge port (15-1b) for this purpose. The second suction port (14-2) sucks the refrigerant into the second outer cylinder chamber (C3), the second a suction port (14-2a) for sucking the refrigerant into the second outer cylinder chamber (C3), and the second inner cylinder chamber (C4). And a second b suction port (14-2b). The second discharge port (15-2) has a second a discharge port (15-2a) for discharging refrigerant from the second outer cylinder chamber (C3) and a refrigerant from the second inner cylinder chamber (C4). It is comprised from the 2b discharge port (15-2b) for discharging.

  In the example of FIG. 6, the low-pressure refrigerant is drawn into the first outer cylinder chamber (C1) from the 1a suction port (14-1a), and the first intermediate pressure refrigerant is discharged from the 1a discharge port (15-1a). The The refrigerant having the first intermediate pressure is sucked into the second outer cylinder chamber (C3) and the second inner cylinder chamber (C4) from the second a suction port (14-2a) and the second b suction port (14-2b). Compressed to 2 intermediate pressure and discharged from the 2a discharge port (15-2a) and 2b discharge port (15-2b). The second intermediate pressure refrigerant is sucked into the first inner cylinder chamber (C2) from the first b suction port (14-1b), is compressed and becomes high-pressure refrigerant, and is discharged from the first b discharge port (15-1b). The

  In the example of FIG. 7, the low-pressure refrigerant is sucked into the first inner cylinder chamber (C2) from the first b suction port (14-1b) and from the second a suction port (14-2a) to the second outer cylinder chamber (C3). ) Is inhaled. In the first inner cylinder chamber (C2) and the second outer cylinder chamber (C3), the refrigerant is boosted to the first intermediate pressure, and the first through the first b discharge port (15-1b) and the second a discharge port (15-2a). Intermediate pressure refrigerant is discharged. The first intermediate pressure refrigerant is sucked into the first outer cylinder chamber (C1) from the first a suction port (14-1a), boosted to the second intermediate pressure, and discharged from the first a discharge port (15-1a). The second intermediate pressure refrigerant is sucked into the second inner cylinder chamber (C4) from the second b suction port (14-2b), is compressed and becomes high pressure refrigerant, and is discharged from the second b discharge port (15-2b). .

  In the example of FIG. 8, the low-pressure refrigerant is sucked into the first outer cylinder chamber (C1) from the first-a suction port (14-1a), is increased to the first intermediate pressure, and is discharged from the first-a discharge port (15-1a). Is done. The first intermediate pressure refrigerant is sucked into the second outer cylinder chamber (C3) from the second a suction port (14-2a), boosted to the second intermediate pressure, and discharged from the second a discharge port (15-2a). . The refrigerant having the second intermediate pressure is sucked into the first inner cylinder chamber (C2) from the second b suction port (14-2b), is boosted to the third intermediate pressure, and is discharged from the second b discharge port (15-1b). . The refrigerant having the third intermediate pressure is sucked into the second inner cylinder chamber (C4) from the second b suction port (14-2b), is compressed and becomes a high pressure refrigerant, and is discharged from the second b discharge port (15-2b). .

  In the example of FIG. 9, the low-pressure refrigerant is sucked into the first outer cylinder chamber (C1) from the first a suction port (14-1a) and from the second b suction port (14-2b) to the second inner cylinder chamber (C4). ) Is inhaled. The refrigerant is boosted to the first intermediate pressure in the first outer cylinder chamber (C1) and the second inner cylinder chamber (C4), and the first through the first a discharge port (15-1a) and the second b discharge port (15-2b). Intermediate pressure refrigerant is discharged. The first intermediate pressure refrigerant is sucked into the second outer cylinder chamber (C3) from the second a suction port (14-2a), is boosted to the second intermediate pressure, and is discharged from the second a discharge port (15-2a). The second intermediate pressure refrigerant is sucked into the first inner cylinder chamber (C2) from the first b suction port (14-1b), is compressed and becomes high-pressure refrigerant, and is discharged from the first b discharge port (15-1b). .

  In the example of FIG. 10, the low-pressure refrigerant is sucked into the first outer cylinder chamber (C1) from the first-a suction port (14-1a), and from the second-a suction port (14-2a) to the second outer cylinder chamber (C3). ) Is inhaled. The refrigerant is boosted to the first intermediate pressure in the first outer cylinder chamber (C1) and the second outer cylinder chamber (C3), and the first through the first a discharge port (15-1a) and the second a discharge port (15-2a). Intermediate pressure refrigerant is discharged. The first intermediate pressure refrigerant is sucked into the first inner cylinder chamber (C2) from the first b suction port (14-1b), boosted to the second intermediate pressure, and discharged from the first a discharge port (15-1a). The second intermediate pressure refrigerant is sucked into the second inner cylinder chamber (C4) from the second b suction port (14-2b), is compressed and becomes high pressure refrigerant, and is discharged from the second b discharge port (15-2b). .

  Even if the refrigerant circuit is configured so as to appropriately switch the operation pattern of FIG. 10 from the example of FIG. 6 above, the state where the four cylinder chambers (C1, C2, C3, C4) are used in series and the state where they are used in parallel are switched. Thus, the volume ratio of the cylinder chamber can be adjusted. Therefore, it is possible to perform an operation in which an optimum COP can be obtained according to the operation conditions.

  In addition, the combination of the low stage side and the high stage side may be arbitrarily changed. For example, it is not necessary to limit the low stage side to the lower cylinder.

Embodiment 1 of the Invention
A first embodiment of the present invention shown in FIGS. 11 and 12 will be described.

In the compressor of the first embodiment , the first suction port (14-1) has one suction for sucking the refrigerant into both the first outer cylinder chamber (C1) and the first inner cylinder chamber (C2). Consists of ports. The first discharge port (15-1) is composed of one discharge port for discharging refrigerant from both the first outer cylinder chamber (C1) and the first inner cylinder chamber (C2). The second suction port (14-2) sucks the refrigerant into the second outer cylinder chamber (C3), the second a suction port (14-2a) for sucking the refrigerant into the second outer cylinder chamber (C3), and the second inner cylinder chamber (C4). And a second b suction port (14-2b). The second discharge port (15-2) includes a second a discharge port (15-2a) for discharging refrigerant from the second outer cylinder chamber (C3) through the space in the casing (10), 2 It is comprised from the 2b discharge port (15-2b) for discharging a refrigerant | coolant from an inner cylinder chamber (C4).

The other configurations related to the compressor (1) are basically the same as those of the base technology .

Next, the refrigerant circuit (60) will be described. The components of the refrigerant circuit (60) are the same as in the base technology .

  The first suction port (14-1) of the compressor (1) is connected to the gas side end of the evaporator (3) via the first suction pipe (61). The first discharge port (15-1) of the compressor (1) is connected to the refrigerant gas outlet (4a) of the gas-liquid separator (4) via the first discharge pipe (63). The outlet (4c) of the gas-liquid separator (4) is connected to the liquid side end of the evaporator (3) via a liquid pipe (66) provided with a second expansion valve (6) in the middle. Yes.

  The first discharge pipe (63) branches in the middle to the first branch pipe (68a), and further branches to the second branch pipe (68b). The first branch pipe (68a) is connected to the second a suction port (14-2a) of the second compression mechanism (30) via a second a suction pipe (62a) having a muffler (9). The second branch pipe (68b) is connected to the second port (P2) of the second three-way valve (switching valve) (7b), and the first port (P1) of the second three-way valve (7b) is connected to the muffler (9). It is connected to the second b suction port (14-2b) of the second compression mechanism (30) via the second b suction pipe (62b). The third port (P3) of the second three-way valve (7b) is connected to the gas side end of the evaporator (3) in the first suction pipe (61) and the first suction port (14-1) by the connecting pipe (67b). ) Is connected between.

  The second a discharge port (15-2a) of the second compression mechanism (30) is connected to one end of the second a discharge pipe (64a), and the other end of the second a discharge pipe (64a) is a gas-liquid separator (4). Connected to the inlet (4b). In the middle of the 2a discharge pipe (64a), a gas cooler (2) and a first expansion valve (5) are provided in order from the 2a discharge port (15-2a) side.

  The second b discharge port (15-2b) of the second compression mechanism (30) is connected to the first port (P1) of the first three-way valve (switching valve) (7a) via the second b discharge pipe (64b). ing. The second port (P2) of the first three-way valve (7a) is connected to a high-pressure introduction pipe (18) provided through the body of the casing (10) through a connection pipe (67c). The third port (P3) of the first three-way valve (7a) is connected between the first discharge port (15-1) and the first branch pipe (68a) in the first discharge pipe (63) by the connecting pipe (67d). It is connected to the.

  Each of the three-way valves (7) has a first position where the first port (P1) and the second port (P2) communicate with each other, and a second position where the first port (P1) and the third port (P3) communicate with each other. It can be switched.

  The three-way valve (7) is a switching mechanism (volume ratio changing means) that switches the flow path of the low-pressure refrigerant, the intermediate-pressure refrigerant, and the high-pressure refrigerant with respect to the compression mechanisms (20, 30). The ratio of the suction volume of the low-stage compression mechanism and the suction volume of the high-stage compression mechanism is changed by changing the connection relationship in the refrigerant circuit (60) of (C1, C2, C3, C4). It is configured.

  The switching mechanism (7) uses both cylinder chambers (C1, C2) of the first compression mechanism (20) as a low-stage compression mechanism and uses both cylinder chambers (C3, C2) of the second compression mechanism (30). C4) is used for the high-stage compression mechanism, and both cylinder chambers (C1, C2) of the first compression mechanism (20) and one cylinder chamber (C3) of the second compression mechanism (30) are compressed on the low-stage side. The mechanism is configured to be switchable between a state where the other cylinder chamber (C4) of the second compression mechanism (30) is used for the high-stage compression mechanism.

  The switching mechanism (volume ratio changing means) (7) is configured to change the ratio of the suction volume of the low-stage compression mechanism and the suction volume of the high-stage compression mechanism in accordance with a change in operating conditions. Yes.

-Driving action-
In this refrigeration apparatus, the first operating state shown in FIG. 11 and the second operating state shown in FIG. 12 can be switched in accordance with changes in operating conditions.

  In the first operating state shown in FIG. 11, both the first three-way valve (7a) and the second three-way valve (7b) are set to the first position. When the compressor is started in this state, the low-pressure gas refrigerant evaporated by exchanging heat with air in the evaporator (3) flows from the first suction port (14-1) of the compressor (1) to the first compression mechanism (20). And is compressed in the outer first cylinder chamber (C1) and the inner first cylinder chamber (C2) to become an intermediate pressure refrigerant. The intermediate pressure refrigerant merges with the refrigerant from the gas-liquid separator (4) and flows into the first branch pipe (68a) and the second branch pipe (68b).

  The intermediate pressure refrigerant flowing through the first branch pipe (68a) is sucked into the second outer cylinder chamber (C3) of the second compression mechanism (30) from the second a suction pipe (62a) and flows through the second branch pipe (68b). The intermediate pressure refrigerant is sucked into the second inner cylinder chamber (C4) of the second compression mechanism (30) from the second b suction pipe (62b). The intermediate pressure refrigerant sucked into the second compression mechanism (30) is compressed into the high pressure refrigerant in the second outer cylinder chamber (C3) and the second inner cylinder chamber (C4). Among the high-pressure refrigerant, in the second inner cylinder chamber (C4), the refrigerant flows out from the second b discharge port (15-2b) and flows into the casing (10) through the connection pipe (67c). Further, the refrigerant that has flowed out of the second outer cylinder chamber (C3) is also discharged into the casing (10). That is, the high pressure refrigerant is filled in the casing (10).

  The high-pressure refrigerant filled in the casing (10) is discharged from the 2a discharge port (15-2a). The refrigerant discharged from the 2a discharge port (15-2a) flows into the gas cooler (2). The refrigerant dissipates heat to the outdoor air by the gas cooler (2), is reduced to an intermediate pressure by the first expansion valve (5), and flows into the gas-liquid separator (4). The liquid refrigerant separated by the gas-liquid separator (4) flows out of the gas-liquid separator (4), is reduced to a low pressure by the second expansion valve (6), is evaporated by the evaporator (3), Inhaled into one compression mechanism (20).

  In the second operating state shown in FIG. 12, the first three-way valve (7a) is set to the second position, and the second three-way valve (7b) is set to the second position. When the compressor (1) is started in this state, a part of the low-pressure gas refrigerant evaporated by exchanging heat with air in the evaporator (3) is discharged from the first suction port (14-1) of the compressor (1). 1 is sucked into the compression mechanism (20) and is compressed in the outer first cylinder chamber (C1) and the inner first cylinder chamber (C2) to be an intermediate pressure refrigerant. The other part of the low-pressure gas refrigerant is sucked from the second three-way valve (7b) through the second b suction port (14-2b) into the second inner cylinder chamber (C4) of the second compression mechanism (30), It becomes an intermediate pressure refrigerant in the second inner cylinder chamber (C4).

  The intermediate pressure refrigerant discharged from the first compression mechanism (20) and the intermediate pressure refrigerant discharged from the second inner cylinder chamber (C4) of the second compression mechanism (30) flow together, and further, a gas-liquid separator. It merges with the refrigerant from (4) and flows into the first branch pipe (68a).

  The intermediate pressure refrigerant flowing through the first branch pipe (68a) is sucked into the second outer cylinder chamber (C3) from the second a suction port (14-2a) of the second compression mechanism (30). The refrigerant sucked into the second outer cylinder chamber (C3) of the second compression mechanism (30) is compressed in the second outer cylinder chamber (C3) to become a high-pressure refrigerant. The high-pressure refrigerant flows out from the second outer cylinder chamber (C3) into the space in the casing (10) and fills the space. The high-pressure refrigerant is discharged from the 2a discharge port (15-2a) and flows into the gas cooler (2). The refrigerant dissipates heat to the outdoor air by the gas cooler (2), is reduced to an intermediate pressure by the first expansion valve (5), and flows into the gas-liquid separator (4). The liquid refrigerant separated by the gas-liquid separator (4) flows out of the gas-liquid separator (4), is reduced to a low pressure by the second expansion valve (6), is evaporated by the evaporator (3), Inhaled into one compression mechanism (20).

-Effect of Embodiment 1-
According to the first embodiment , the suction volume of the low-pressure refrigerant in the second operation state is larger than the suction volume of the low-pressure refrigerant in the first operation state. Further, the suction volume of the intermediate pressure refrigerant in the second operation state is smaller than the suction volume of the intermediate pressure refrigerant in the first operation state.

  That is, in the first operation state and the second operation state, the low stage intake amount is larger in the second operation state than in the first operation state, while the high stage intake amount is in the first operation state. The second operating state is smaller than that.

  As described above, in this embodiment, the cylinder chamber of the second compression mechanism (30) is used by recombination between the first operation state and the second operation state. In the compressor (1) in which two compression mechanisms (20, 30) are mechanically connected, the suction volume of the low-stage compression mechanism and the suction of the high-stage compression mechanism in the first operation state and the second operation state The volume ratio can be adjusted. Therefore, by adjusting the suction volume ratio of the compressor in accordance with the operating conditions, it is possible to perform an operation with a high COP (coefficient of performance). In addition, torque fluctuations associated with refrigerant compression can be adjusted.

-Modification of Embodiment 1-
FIGS. 13 to 21 illustrate switching patterns when the four cylinder chambers of the first compression mechanism (20) and the second compression mechanism (30) are used in combination. Each figure is a cross-sectional view of the main part.

  In these examples, the first suction port (14-1) includes a first a suction port (14-1a) for sucking refrigerant into the first outer cylinder chamber (C1), and a first inner cylinder chamber (C2). It is constituted by a 1b suction port (14-1b) for sucking refrigerant into the tank. The first discharge port (15-1) discharges refrigerant from the first a discharge port (15-1a) for discharging refrigerant from the first outer cylinder chamber (C1) and from the first inner cylinder chamber (C2). 1b discharge port (15-1b) for this purpose. The second suction port (14-2) sucks the refrigerant into the second outer cylinder chamber (C3), the second a suction port (14-2a) for sucking the refrigerant into the second outer cylinder chamber (C3), and the second inner cylinder chamber (C4). And a second b suction port (14-2b). The second discharge port (15-2) has a second a discharge port (15-2a) for discharging refrigerant from the second outer cylinder chamber (C3) and a refrigerant from the second inner cylinder chamber (C4). It is comprised from the 2b discharge port (15-2b) for discharging.

  In the example of FIG. 13, the low-pressure refrigerant is sucked into the first outer cylinder chamber (C1) and the first inner cylinder chamber (C2) from the 1a suction port (14-1a) and the 1b suction port (14-1b). At the same time, the air is drawn into the second outer cylinder chamber (C3) from the second a suction port (14-2a), compressed, and pressurized to the intermediate pressure refrigerant. The intermediate pressure refrigerant is discharged from the first-a discharge port (15-1a), the first-b discharge port (15-1b), and the second-a discharge port (15-2a), and from the second-b suction port (14-2b) to the second inner side. Inhaled into the cylinder chamber (C4). The intermediate pressure refrigerant is compressed in the second inner cylinder chamber (C4) to become a high pressure refrigerant, and is discharged from the second b discharge port (15-2b).

  In the example of FIG. 14, the low-pressure refrigerant is sucked into the first outer cylinder chamber (C1) from the 1a suction port (14-1a), compressed, and boosted to the first intermediate pressure. The refrigerant of the first intermediate pressure is sucked into the second outer cylinder chamber (C3) and the second inner cylinder chamber (C4) from the second a suction port (14-2a) and the second b suction port (14-2b) and compressed. Thus, the pressure is raised to the second intermediate pressure. The second intermediate pressure refrigerant is sucked into the first inner cylinder chamber (C2) from the first b suction port (14-1b), compressed to become a high pressure refrigerant, and discharged from the first b discharge port (15-1b). The

  In the example of FIG. 15, the low-pressure refrigerant is sucked into the first inner cylinder chamber (C2) from the first b suction port (14-1b) and from the second a suction port (14-2a) to the second outer cylinder chamber (C3). ), And compressed to an intermediate pressure. The intermediate pressure refrigerant is discharged from the 1b discharge port (15-1b) and the 2a discharge port (15-2a). The intermediate pressure refrigerant is sucked into the first outer cylinder chamber (C1) from the first a suction port (14-1a) and is sucked into the second outer cylinder chamber (C3) from the second b suction port (14-2b). The In the first outer cylinder chamber (C1) and the second inner cylinder chamber (C4), the intermediate pressure refrigerant is compressed into high pressure refrigerant. The high-pressure refrigerant is discharged from the first-a discharge port (15-1a) and the second-b discharge port (15-2b).

  In the example of FIG. 16, the low-pressure refrigerant is sucked into the first outer cylinder chamber (C1) and the first inner cylinder chamber (C2) from the 1a suction port (14-1a) and the 1b suction port (14-1b). At the same time, the air is sucked into the second inner cylinder chamber (C4) from the second b suction port (14-2b), compressed, and pressurized to the intermediate pressure refrigerant. The intermediate pressure refrigerant is discharged from the first-a discharge port (15-1a), the first-b discharge port (15-1b), and the second-b discharge port (15-2b), and from the second-a suction port (14-2a) to the second outer side. Inhaled into the cylinder chamber (C3). The intermediate pressure refrigerant is compressed in the second outer cylinder chamber (C3) to become a high pressure refrigerant, and is discharged from the second a discharge port (15-2a).

  In the example of FIG. 17, the low-pressure refrigerant is sucked into the first outer cylinder chamber (C1) from the 1a suction port (14-1a), compressed, and pressurized to an intermediate pressure. The intermediate-pressure refrigerant is discharged from the 1a discharge port (15-1a), from the 1b intake port (14-1b) to the first inner cylinder chamber (C2), and from the 2a intake port (14-2a) to the second. The air is sucked into the outer cylinder chamber (C3) from the second b suction port (14-2b) into the second inner cylinder chamber (C4). The intermediate pressure refrigerant is compressed in the first inner cylinder chamber (C2), the second outer cylinder chamber (C3), and the second inner cylinder chamber (C4) to become a high pressure refrigerant. The high-pressure refrigerant is discharged from the first b discharge port (15-1b), the second a discharge port (15-2a), and the second b discharge port (15-2b).

  In the example of FIG. 18, the low-pressure refrigerant is sucked into the first outer cylinder chamber (C1) from the first a suction port (12-1a) and from the second b suction port (14-2b) to the second inner cylinder chamber ( C4) is sucked in, compressed, and pressurized to an intermediate pressure refrigerant. The intermediate pressure refrigerant is discharged from the first-a discharge port (15-1a) and the second-b discharge port (15-2b), and is sucked from the first-b suction port (14-1b) into the first inner cylinder chamber (C2). The air is sucked into the second outer cylinder chamber (C3) from the port (14-2a). In the first inner cylinder chamber (C2) and the second outer cylinder chamber (C3), the intermediate pressure refrigerant is compressed into high pressure refrigerant. The high-pressure refrigerant is discharged from the first b discharge port (15-1b) and the second a discharge port (15-2a).

  In the example of FIG. 19, the low-pressure refrigerant is sucked into the first inner cylinder chamber (C2) from the 1b suction port (14-1b), and the 2a suction port (14-2a) and the 2b suction port (14). -2b) is sucked into the second outer cylinder chamber (C3) and the second inner cylinder chamber (C4), compressed, and pressurized to the intermediate pressure refrigerant. The intermediate pressure refrigerant is discharged from the 1b discharge port (15-1b), the 2a discharge port (15-2a), and the 2b discharge port (15-2b), and is discharged from the 1a intake port (14-1a) to the first. Inhaled into the outer cylinder chamber (C1). The intermediate pressure refrigerant is compressed in the first outer cylinder chamber (C1) to become a high pressure refrigerant, and is discharged from the first a discharge port (15-1a).

  In the example of FIG. 20, the low-pressure refrigerant is sucked into the first outer cylinder chamber (C1) from the first a suction port (14-1a) and from the first b suction port (14-1b) to the first inner cylinder chamber ( C2) is sucked in, compressed and boosted to an intermediate pressure. The intermediate pressure refrigerant is discharged from the first-a discharge port (15-1a) and the first-b discharge port (15-1b). The intermediate pressure refrigerant is sucked into the second outer cylinder chamber (C3) from the second a suction port (14-2a) and sucked into the second inner cylinder chamber (C4) from the second b suction port (14-2b). Is done. The intermediate pressure refrigerant is compressed in the second outer cylinder chamber (C3) and the second inner cylinder chamber (C4) to become a high-pressure refrigerant, and the second a discharge port (15-2a) and the second b discharge port (15-2b). It is discharged from.

  In the example of FIG. 21, the low-pressure refrigerant is sucked into the first outer cylinder chamber (C1) from the 1a suction port (14-1a) and from the 2a suction port (14-2a) to the second outer cylinder chamber ( C3) is sucked in, compressed and boosted to an intermediate pressure. The intermediate pressure refrigerant is discharged from the first-a discharge port (15-1a) and the second-a discharge port (15-2a). The intermediate pressure refrigerant is sucked into the first inner cylinder chamber (C2) from the first b suction port (14-1b) and sucked into the second inner cylinder chamber (C4) from the second b suction port (14-2b). Is done. The intermediate pressure refrigerant is compressed in the first inner cylinder chamber (C2) and the second inner cylinder chamber (C4) to become high-pressure refrigerant, and the first b discharge port (15-1b) and the second b discharge port (15-2b). It is discharged from.

  Even if the refrigerant circuit is configured such that the examples in FIG. 13 to the examples in FIG. 21 are appropriately combined and switched to each other, the suction volume of the low-stage compression mechanism can be changed by changing the connection relationship of the four cylinder chambers. And the ratio of the suction volume of the high-stage compression mechanism can be changed. Therefore, it is possible to perform an operation in which an optimum COP can be obtained according to the operation conditions.

<< Embodiment 2 of the Invention >>
A second embodiment of the present invention shown in FIGS. 22 and 23 will be described.

In the compressor (1) of the second embodiment , the first suction port (14-1) includes a first a suction port (14-1a) for sucking refrigerant into the first outer cylinder chamber (C1), 1 It is comprised from the 1b suction port (14-1b) for suck | inhaling a refrigerant | coolant to an inner cylinder chamber (C2). The first discharge port (15-1) discharges refrigerant from the first a discharge port (15-1a) for discharging refrigerant from the first outer cylinder chamber (C1) and from the first inner cylinder chamber (C2). 1b discharge port (15-1b). The second suction port (14-2) sucks the refrigerant into the second outer cylinder chamber (C3), the second a suction port (14-2a) for sucking the refrigerant into the second outer cylinder chamber (C3), and the second inner cylinder chamber (C4). And a second b suction port (14-2b). The second discharge port (15-2) includes a second a discharge port (15-2a) for discharging refrigerant from the second outer cylinder chamber (C3), and a casing ( 10) It is comprised from the 2b discharge port (15-2b) for discharging a refrigerant | coolant through the space in.

The rest of the configuration related to the compressor (1) is basically the same as the base technology .

Next, the refrigerant circuit (60) will be described. The components of the refrigerant circuit (60) are the same as in the base technology .

  The 1a suction port (14-1a) of the compressor (1) is connected to the gas side end of the evaporator (3) via the 1a suction pipe (61a). The 1a discharge port (15-1a) of the compressor (1) is connected to the refrigerant gas outlet (4a) of the gas-liquid separator (4) via the 1a discharge pipe (63a). The outlet (4c) of the gas-liquid separator (4) is connected to the liquid side end of the evaporator (3) via a liquid pipe (66) provided with a second expansion valve (6) in the middle. Yes.

  The 1a discharge pipe (63a) branches into the 1st branch pipe (68a) and the 2nd branch pipe (68b). The second branch pipe (68b) has a muffler (9) and is connected to the second b suction port (14-2b) of the second compression mechanism (30) via the second b suction pipe (62b). The first branch pipe (68a) is connected to the first port (P1) of the second four-way switching valve (switching valve) (8b). The second port (P2) of the second four-way switching valve (8b) is connected to one end of a 2a suction pipe (62a) having a muffler (9), and the other end of the second a suction pipe (62a) is second compressed. It is connected to the 2a suction port (14-2a) of the mechanism (30). The third port (P3) of the second four-way selector valve (8b) is connected between the gas side end of the evaporator (3) and the muffler (9) in the 1a suction pipe (61a). The fourth port (P4) of the second four-way selector valve (8b) is connected to one end of a 1b suction pipe (61b) having a muffler (9), and the other end of the first b suction pipe (61b) is connected to the first b. It is connected to the suction port (14-1b).

  One end of the 1b discharge pipe (63b) is connected to the 1b discharge port (15-1b), and the other end of the 1b discharge pipe (63b) is the first four-way switching valve (switching valve) (8a). Connected to 1 port (P1). One end of the connection pipe (67e) is connected to the second port (P2) of the second four-way selector valve (8b), and the other end of the connection pipe (67e) is the first in the first-a discharge pipe (63a). It is connected between the discharge port (15-1) and the first branch pipe (68a).

  The 2a discharge port (15-2a) is connected to the 3rd port (P3) of the 1st four way switching valve (8a) by the 2a discharge pipe (64a). One end of the second b discharge pipe (64b) is connected to the second b discharge port (15-2b), and the other end of the second b discharge pipe (64b) is connected to the inlet (4b) of the gas-liquid separator (4). It is connected. In the middle of the second b discharge pipe (64b), a gas cooler (2) and a first expansion valve (5) are provided in this order from the second b discharge port (15-2b) side. The fourth port (P4) of the first four-way selector valve (8a) is connected to the second b discharge port (15-2b) in the second b discharge pipe (64b) and the gas cooler (2) via the connecting pipe (67f). Connected between.

  Each of the four-way switching valves (8a, 8b) has a first position (P1) and a second port (P2) communicating with each other and a third port (P3) and a fourth port (P4) communicating with each other. 22) and the second position (see FIG. 23) where the first port (P1) and the fourth port (P4) communicate with each other and the second port (P2) and the third port (P3) communicate with each other. It is configured to be able to.

  The four-way switching valve (8a, 8b) is a switching mechanism (volume ratio changing means) that switches the flow path of the low-pressure refrigerant, the intermediate-pressure refrigerant, and the high-pressure refrigerant to the compression mechanisms (20, 30). By changing the connection relationship in the refrigerant circuit (60) of the four cylinder chambers (C1, C2, C3, C4), the ratio of the suction volume of the low-stage compression mechanism to the suction volume of the high-stage compression mechanism can be changed. Is configured to change.

  The switching mechanism (8a, 8b) uses both cylinder chambers (C1, C2) of the first compression mechanism (20) as a low-stage compression mechanism and both cylinder chambers ( C3 and C4) are used for the high-stage compression mechanism, and one cylinder chamber (C2) of the first compression mechanism (20) and one cylinder chamber (C4) of the second compression mechanism (30) are connected to the low-stage side. Can be switched between the state in which the other cylinder chamber (C1) of the first compression mechanism (20) and the other cylinder chamber (C3) of the second compression mechanism (30) are used for the high-stage compression mechanism. It is configured.

  In addition, the switching mechanism (volume ratio changing means) (8a, 8b) is configured to change the ratio of the suction volume of the low-stage compression mechanism and the suction volume of the high-stage compression mechanism in accordance with changes in operating conditions. Has been.

-Driving action-
In this refrigeration apparatus, the first operating state shown in FIG. 22 and the second operating state shown in FIG. 23 can be switched in accordance with changes in operating conditions.

  In the first operating state shown in FIG. 22, both the first four-way switching valve (8a) and the second four-way switching valve (8b) are set to the first position. When the compressor (1) is started in this state, the low-pressure gas refrigerant evaporated by exchanging heat with air in the evaporator (3) becomes the 1a suction port (14-1a) and 1b suction port of the compressor (1). (14-1b) is sucked into the first compression mechanism (20) and is compressed in the outer first cylinder chamber (C1) and the inner first cylinder chamber (C2) to become an intermediate pressure refrigerant. The intermediate-pressure refrigerant flows through the first four-way switching valve (8a) and flows, and further merges with the refrigerant from the gas-liquid separator (4) to form the first branch pipe (68a) and the second branch pipe ( 68b).

  The intermediate pressure refrigerant flowing through the first branch pipe (68a) passes through the second four-way selector valve (8b) from the second a suction pipe (62a) to the second outer cylinder chamber (C3) of the second compression mechanism (30). The intermediate pressure refrigerant that is sucked and flows through the second branch pipe (68b) is sucked into the second inner cylinder chamber (C4) of the second compression mechanism (30) from the second b suction pipe (62b). The intermediate pressure refrigerant sucked into the second compression mechanism (30) is compressed into the high pressure refrigerant in the second outer cylinder chamber (C3) and the second inner cylinder chamber (C4). Among the high-pressure refrigerant, in the second outer cylinder chamber (C3), the refrigerant flows out from the 2a discharge port (15-2a) and flows through the connection pipe (67f) through the first four-way switching valve (8a). . On the other hand, the high-pressure refrigerant flowing out from the second inner cylinder chamber (C4) is discharged into the casing (10) and filled in the casing (10), and then discharged from the second b discharge port (15-2b). The high-pressure refrigerant from the 2a discharge port (15-2a) and the high-pressure refrigerant from the 2b discharge port (15-2b) merge and flow into the gas cooler (2). The refrigerant dissipates heat to the outdoor air by the gas cooler (2), is reduced to an intermediate pressure by the first expansion valve (5), and flows into the gas-liquid separator (4). The liquid refrigerant separated by the gas-liquid separator (4) flows out of the gas-liquid separator (4), is reduced to a low pressure by the second expansion valve (6), is evaporated by the evaporator (3), Inhaled into one compression mechanism (20).

  In the second operating state shown in FIG. 23, both the first four-way switching valve (8a) and the second four-way switching valve (8b) are set to the second position. When the compressor (1) is started in this state, a part of the low-pressure gas refrigerant evaporated by exchanging heat with air in the evaporator (3) passes through the first a suction port (14-1a) of the compressor (1). While being sucked into the first compression mechanism (20) and sucked into the second compression mechanism (30) from the second a suction port (14-2a), the first outer cylinder chamber (C1) and the second outer cylinder chamber (C3 ) To be an intermediate pressure refrigerant.

  The intermediate pressure refrigerant discharged from the outer first cylinder chamber (C1) of the first compression mechanism (20) and the intermediate pressure refrigerant discharged from the second outer cylinder chamber (C3) of the second compression mechanism (30) are 1 flows through the four-way switching valve (8a) and further flows into the first branch pipe (68a) and the second branch pipe (68b) after joining with the refrigerant from the gas-liquid separator (4).

  The intermediate pressure refrigerant flowing through the second branch pipe (68b) is sucked into the second inner cylinder chamber (C4) from the second b suction port (14-2b) of the second compression mechanism (30). The refrigerant sucked into the second inner cylinder chamber (C4) of the second compression mechanism (30) is compressed in the second inner cylinder chamber (C4) to become a high-pressure refrigerant. The high-pressure refrigerant flows out from the second inner cylinder chamber (C4) into the space in the casing (10) and fills the space, and is then discharged from the second b discharge port (15-2b).

  On the other hand, the intermediate pressure refrigerant flowing through the first branch pipe (68a) passes through the second four-way switching valve (8b) from the first b suction pipe (14-1b) to the first inner cylinder of the first compression mechanism (20). Inhaled into chamber (C2). In the first inner cylinder chamber (C2), the refrigerant is compressed into a high-pressure refrigerant. The high-pressure refrigerant flows out of the casing (10) from the first inner cylinder chamber (C2) through the first b discharge port (15-1b). The high-pressure refrigerant discharged from the first b discharge port (15-1b) merges with the high-pressure refrigerant discharged from the second b discharge port (15-2b) and flows into the gas cooler (2). The refrigerant dissipates heat to the outdoor air by the gas cooler (2), is reduced to an intermediate pressure by the first expansion valve (5), and flows into the gas-liquid separator (4). The liquid refrigerant separated by the gas-liquid separator (4) flows out of the gas-liquid separator (4), is reduced to a low pressure by the second expansion valve (6), and then is evaporated by the evaporator (3). Inhaled into one compression mechanism (20).

-Effect of Embodiment 2-
According to the second embodiment , since the outer cylinder chambers (C1, C3) are larger than the inner cylinder chambers (C2, C4), the low pressure refrigerant in the second operation state is larger than the suction volume of the low pressure refrigerant in the first operation state. The suction volume increases. Further, the suction volume of the intermediate pressure refrigerant in the second operation state is smaller than the suction volume of the intermediate pressure refrigerant in the second operation state.

  That is, in the first operating state and the second operating state, the low stage suction volume is larger in the second operating state than in the first operating state, while the high stage suction volume is in the first operating state. The second operating state is smaller than that.

  Thus, in this embodiment, the cylinder chambers (C1, C2, C3, C4) of the first compression mechanism (20) and the second compression mechanism (30) are rearranged between the first operation state and the second operation state. In the compressor (1) in which the two compression mechanisms (20, 30) are mechanically coupled to one shaft (53), the first operating state and the second operating state are used. The ratio of the suction volume of the low-stage compression mechanism to the suction volume of the high-stage compression mechanism can be adjusted. Therefore, by adjusting the suction volume ratio of the compression ratio according to the operating conditions, it becomes possible to perform an operation with a high COP (coefficient of performance).

<< Reference Technology 1 of Invention >>
Reference technology 1 of the present invention shown in FIGS. 24 and 25 will be described.

In the compressor (1) of the reference technique 1 , the first suction port (14-1) is a 1 for sucking refrigerant into both the first outer cylinder chamber (C1) and the first inner cylinder chamber (C2). It is composed of a book intake port. The first discharge port (15-1) is composed of one discharge port for discharging refrigerant from both the first outer cylinder chamber (C1) and the first inner cylinder chamber (C2). The second suction port (14-2) is constituted by a single suction port for sucking refrigerant into both the second outer cylinder chamber (C3) and the second inner cylinder chamber (C4). The second discharge port (15-2) includes a second a discharge port (15-2a) for discharging refrigerant from the second outer cylinder chamber (C3) through the space in the casing (10), 2 It is comprised from the 2b discharge port (15-2b) for discharging a refrigerant | coolant from an inner cylinder chamber (C4).

The other configurations related to the compressor (1) are basically the same as those of the base technology .

Next, the refrigerant circuit (60) will be described. The components of the refrigerant circuit (60) are the same as in the base technology .

  The first suction port (14-1) of the compressor (1) is connected to the gas side end of the evaporator (3) via the first suction pipe (61). The first discharge port (15-1) of the compressor (1) is connected to the refrigerant gas outlet (4a) of the gas-liquid separator (4) via the first discharge pipe (63). The outlet (4c) of the gas-liquid separator (4) is connected to the liquid side end of the evaporator (3) via a liquid pipe (66) provided with a second expansion valve (6) in the middle. Yes.

  The first discharge pipe (63) is branched into the branch pipe (68) on the way. The branch pipe (68) is connected to the second suction port (14-2) of the second compression mechanism (30) by the second suction pipe (62).

  The second a discharge port (15-2a) of the second compression mechanism (30) is connected to one end of the second a discharge pipe (64a), and the other end of the second a discharge pipe (64a) is a gas-liquid separator (4). Connected to the inlet (4b). In the middle of the 2a discharge pipe (64a), a gas cooler (2) and a first expansion valve (5) are provided in order from the 2a discharge port (15-2a) side.

  The second b discharge port (15-2b) of the second compression mechanism (30) is connected to the first port (P1) of the three-way valve (7) via the second b discharge pipe (64b). The second port (P2) of the three-way valve (7) is connected to a high-pressure introduction pipe (18) provided through the body of the casing (10) through a connection pipe (67c). The third port (P3) of the three-way valve (7) is connected between the first discharge port (15-1) and the first branch pipe (68a) in the first discharge pipe (63) by the connecting pipe (67d). Has been.

  The three-way valve (7) switches between a first position where the first port (P1) and the second port (P2) communicate with each other and a second position where the first port (P1) and the third port (P3) communicate with each other. It is configured to be able to.

  The three-way valve (7) is a switching mechanism (volume ratio changing means) that switches the flow path of the low-pressure refrigerant, the intermediate-pressure refrigerant, and the high-pressure refrigerant with respect to the compression mechanisms (20, 30). The ratio of the suction volume of the low-stage compression mechanism and the suction volume of the high-stage compression mechanism is changed by changing the connection relationship in the refrigerant circuit (60) of (C1, C2, C3, C4). It is configured.

  The switching mechanism (7) has both cylinder chambers of the second compression mechanism (30) when the first compression mechanism (20) is on the low stage side and the second compression mechanism (30) is on the high stage side. (C3, C4) compresses the refrigerant in a state where a pressure difference occurs between the suction side and the discharge side, and compresses the refrigerant in one cylinder chamber (outer cylinder chamber) (C3) of the second compression mechanism (30). While there is a pressure difference between the suction side and the discharge side, the other cylinder chamber (inner cylinder chamber) (C4) can be switched between a state where the suction side and the discharge side are substantially at the same pressure and the refrigerant passes uncompressed. It is configured. That is, the refrigerant can pass through the inner cylinder chamber (C4).

  In addition, the switching mechanism (volume ratio changing means) (7) changes the ratio of the suction volume of the low-stage compression mechanism (20) and the suction volume of the high-stage compression mechanism (30) in accordance with changes in operating conditions. Is configured to do.

-Driving action-
In this air conditioner, the first operating state shown in FIG. 24 and the second operating state shown in FIG. 25 can be switched in accordance with a change in operating conditions.

  In the first operating state shown in FIG. 24, the three-way valve (7) is set to the first position. When the compressor (1) is started in this state, the low-pressure gas refrigerant evaporated by exchanging heat with the air in the evaporator (3) passes through the first suction pipe (61) to the first compressor (1). The refrigerant is sucked into the first compression mechanism (20) from the suction port (14-1), and is compressed in the outer first cylinder chamber (C1) and the inner first cylinder chamber (C2) to be an intermediate pressure refrigerant. The intermediate pressure refrigerant merges with the refrigerant from the gas-liquid separator (4) and flows into the branch pipe (68).

  The intermediate pressure refrigerant flowing through the branch pipe (68) flows from the second suction pipe (62) and the second suction port (14-2) to the second outer cylinder chamber (C3) and the second inner cylinder of the second compression mechanism (30). Inhaled into chamber (C4). The intermediate pressure refrigerant sucked into the second compression mechanism (30) is compressed into the high pressure refrigerant in the second outer cylinder chamber (C3) and the second inner cylinder chamber (C4). Among the high-pressure refrigerant, on the second inner cylinder chamber (C4) side, the refrigerant flows out from the second b discharge port (15-2b) and flows into the casing (10) from the connection pipe (67c). Further, the refrigerant that has flowed out of the second outer cylinder chamber (C3) is also discharged into the casing (10). That is, the high pressure refrigerant is filled in the casing (10).

  The high-pressure refrigerant filled in the casing (10) is discharged from the 2a discharge port (15-2a). The refrigerant discharged from the 2a discharge port (15-2a) flows into the gas cooler (2). The refrigerant dissipates heat to the outdoor air by the gas cooler (2), is reduced to an intermediate pressure by the first expansion valve (5), and flows into the gas-liquid separator (4). The liquid refrigerant separated by the gas-liquid separator (4) flows out of the gas-liquid separator (4), is reduced to a low pressure by the second expansion valve (6), is evaporated by the evaporator (3), Inhaled into one compression mechanism (20).

  In the second operating state shown in FIG. 25, the three-way valve (7) is set to the second position. When the compressor (1) is started in this state, the low-pressure gas refrigerant evaporated by exchanging heat with air in the evaporator (3) is transferred to the first suction pipe (61) and the first suction port (14) of the compressor (1). -1) is sucked into the first compression mechanism (20) and is compressed in the outer first cylinder chamber (C1) and the inner first cylinder chamber (C2) to become an intermediate pressure refrigerant. The intermediate pressure refrigerant discharged from the first compression mechanism (20) merges with the refrigerant from the gas-liquid separator (4) and flows into the branch pipe (68).

  The intermediate pressure refrigerant flowing through the branch pipe (68) is sucked into the second outer cylinder chamber (C3) and the second inner cylinder chamber (C4) from the second suction port (14-2) of the second compression mechanism (30). The The refrigerant sucked into the second outer cylinder chamber (C3) of the second compression mechanism (30) is compressed in the second outer cylinder chamber (C3) to become a high-pressure refrigerant. The high-pressure refrigerant flows out from the second outer cylinder chamber (C3) into the space in the casing (10) and fills the space. The high-pressure refrigerant is discharged from the 2a discharge port (15-2a) and flows into the gas cooler (2). The refrigerant dissipates heat to the outdoor air by the gas cooler (2), is reduced to an intermediate pressure by the first expansion valve (5), and flows into the gas-liquid separator (4). The liquid refrigerant separated by the gas-liquid separator (4) flows out of the gas-liquid separator (4), is reduced to a low pressure by the second expansion valve (6), is evaporated by the evaporator (3), Inhaled into one compression mechanism (20).

  On the other hand, the refrigerant sucked into the second inner cylinder chamber (C4) of the second compression mechanism (30) has the second b discharge port (15-2b) set to the first by switching the three-way valve (7) to the second position. It communicates with the discharge pipe (63). That is, the second b discharge port (15-2b) is at an intermediate pressure. Therefore, the intermediate pressure refrigerant sucked into the second inner cylinder chamber (C4) flows out (through) from the second b discharge port (15-2b) with the intermediate pressure without being substantially compressed. By doing so, the cylinder volume (discharge volume) of the second compression mechanism (30) is smaller in the second operating state than in the first operating state.

-Effects of Reference Technology 1-
According to this reference technique 1 , the suction volume of the low-pressure refrigerant in the first operation state is the same as the suction volume of the low-pressure refrigerant in the second operation state. On the other hand, the suction volume of the intermediate pressure refrigerant in the second operation state is smaller than the suction discharge volume of the intermediate pressure refrigerant in the first operation state.

  That is, in the first operation state and the second operation state, the low stage intake volume is the same in the first operation state and the second operation state, while the high stage intake volume is higher than that in the first operation state. However, the second operating state becomes smaller.

In the present reference technology , the inner cylinder chamber of the second compression mechanism (30) is configured to pass through the refrigerant in the second operation state, so that the two compression mechanisms (20 , 30) in the mechanically connected compressor (1), the ratio of the suction volume of the low-stage compression mechanism and the suction volume of the high-stage compression mechanism in the first operation state and the second operation state is adjusted. can do. Therefore, by adjusting the suction volume ratio of the compression ratio according to the operating conditions, it becomes possible to perform an operation with a high COP (coefficient of performance).

<< Reference Technology 2 of Invention >>
Reference technique 2 of the present invention shown in FIGS. 26 and 27 will be described.

In the compressor (1) of the reference technique 2 , the first suction port (14-1) is a 1 for sucking refrigerant into both the first outer cylinder chamber (C1) and the first inner cylinder chamber (C2). It is composed of a book intake port. The first discharge port (15-1) is composed of one discharge port for discharging refrigerant from both the first outer cylinder chamber (C1) and the first inner cylinder chamber (C2). The second suction port (14-2) is constituted by a single suction port for sucking refrigerant into both the second outer cylinder chamber (C3) and the second inner cylinder chamber (C4). The second discharge port (15-2) includes a second a discharge port (15-2a) for discharging refrigerant from the second outer cylinder chamber (C3), and a casing ( 10) It is comprised from the 2b discharge port (15-2b) for discharging a refrigerant | coolant through the space in.

The other configurations related to the compressor (1) are basically the same as those of the base technology .

Next, the refrigerant circuit (60) will be described. The components of the refrigerant circuit (60) are the same as in the base technology .

  The first suction port (14-1) of the compressor (1) is connected to the gas side end of the evaporator (3) via the first suction pipe (61). The first discharge port (15-1) of the compressor (1) is connected to the refrigerant gas outlet (4a) of the gas-liquid separator (4) via the first discharge pipe (63). The outlet (4c) of the gas-liquid separator (4) is connected to the liquid side end of the evaporator (3) via a liquid pipe (66) provided with a second expansion valve (6) in the middle. Yes.

  The first discharge pipe (63) is branched into the branch pipe (68) on the way. The branch pipe (68) is connected to the second suction port (14-2) of the second compression mechanism (30) by the second suction pipe (62).

  The second b discharge port (15-2b) of the second compression mechanism (30) is connected to one end of the second b discharge pipe (64b), and the other end of the second b discharge pipe (64b) is the gas-liquid separator (4). Connected to the inlet (4b). In the middle of the second b discharge pipe (64b), a gas cooler (2) and a first expansion valve (5) are provided in this order from the second b discharge port (15-2b) side.

  The second a discharge port (15-2a) of the second compression mechanism (30) is connected to the first port (P1) of the three-way valve (7) via the second a discharge pipe (64a). A second connection pipe (67i) is connected to the second port (P2) of the three-way valve (7), and the second connection pipe (67i) is connected to the second b discharge port (15b in the second b discharge pipe (64b)). -2b) and gas cooler (2). The first connection pipe (67j) is connected to the third port (P3) of the three-way valve (7), and the first connection pipe (67j) joins the first discharge pipe (63).

  The three-way valve (7) switches between a first position where the first port (P1) and the second port (P2) communicate with each other and a second position where the first port (P1) and the third port (P3) communicate with each other. It is configured to be able to.

  The three-way valve (7) is a switching mechanism (volume ratio changing means) that switches the flow path of the low-pressure refrigerant, the intermediate-pressure refrigerant, and the high-pressure refrigerant with respect to the compression mechanisms (20, 30). The ratio of the suction volume of the low-stage compression mechanism and the suction volume of the high-stage compression mechanism is changed by changing the connection relationship in the refrigerant circuit (60) of (C1, C2, C3, C4). It is configured.

  The switching mechanism (7) has both cylinder chambers of the second compression mechanism (30) when the first compression mechanism (20) is on the low stage side and the second compression mechanism (30) is on the high stage side. (C3, C4) compresses the refrigerant in a state where a pressure difference occurs between the suction side and the discharge side, and compresses the refrigerant in one cylinder chamber (inner cylinder chamber) (C4) of the second compression mechanism (30). While there is a pressure difference between the suction side and the discharge side, the other cylinder chamber (outer cylinder chamber) (C3) can be switched between a state where the suction side and the discharge side are at substantially the same pressure and the refrigerant passes uncompressed. It is configured. In other words, the refrigerant can pass through the outer cylinder chamber (C3).

  The switching mechanism (volume ratio changing means) is configured to change the ratio of the suction volume of the low-stage compression mechanism and the suction volume of the high-stage compression mechanism in accordance with a change in operating conditions.

-Driving action-
In this air conditioner, the first operating state shown in FIG. 26 and the second operating state shown in FIG. 27 can be switched in accordance with a change in operating conditions.

  In the first operating state shown in FIG. 26, the three-way valve (7) is set to the first position. When the compressor (1) is started in this state, the low-pressure gas refrigerant evaporated by exchanging heat with the air in the evaporator (3) passes through the first suction pipe (61) to the first compressor (1). The refrigerant is sucked into the first compression mechanism (20) from the suction port (14-1), and is compressed in the outer first cylinder chamber (C1) and the inner first cylinder chamber (C2) to be an intermediate pressure refrigerant. The intermediate pressure refrigerant merges with the refrigerant from the gas-liquid separator (4) and flows into the branch pipe (68).

  The intermediate pressure refrigerant flowing through the branch pipe (68) flows from the second suction pipe (62) and the second suction port (14-2) to the second outer cylinder chamber (C3) and the second inner cylinder of the second compression mechanism (30). Inhaled into chamber (C4). The intermediate pressure refrigerant sucked into the second compression mechanism (30) is compressed into the high pressure refrigerant in the second outer cylinder chamber (C3) and the second inner cylinder chamber (C4). Among these high-pressure refrigerants, on the second outer cylinder chamber (C3) side, the refrigerant flows out from the 2a discharge port (15-2a) and passes through the second connection pipe (67i) from the three-way valve (7) to the second b. Join the discharge pipe (64b). On the second inner cylinder chamber (C4) side, the refrigerant is discharged from the second b discharge port (15-2b) through the casing (10).

  The refrigerant discharged from the second b discharge port (15-2b) merges with the refrigerant from the second a discharge port (15-2a) and flows into the gas cooler (2). The refrigerant dissipates heat to the outdoor air by the gas cooler (2), is reduced to an intermediate pressure by the first expansion valve (5), and flows into the gas-liquid separator (4). The liquid refrigerant separated by the gas-liquid separator (4) flows out of the gas-liquid separator (4), is reduced to a low pressure by the second expansion valve (6), is evaporated by the evaporator (3), Inhaled into one compression mechanism (20).

  In the second operating state shown in FIG. 27, the three-way valve (7) is set to the second position. When the compressor (1) is started in this state, the low-pressure gas refrigerant evaporated by exchanging heat with air in the evaporator (3) is transferred to the first suction pipe (61) and the first suction port (14) of the compressor (1). -1) is sucked into the first compression mechanism (20) and is compressed in the outer first cylinder chamber (C1) and the inner first cylinder chamber (C2) to become an intermediate pressure refrigerant. The intermediate pressure refrigerant discharged from the first compression mechanism (20) merges with the refrigerant from the gas-liquid separator (4) and flows into the branch pipe (68).

  The intermediate pressure refrigerant flowing through the branch pipe (68) is sucked into the second outer cylinder chamber (C3) and the second inner cylinder chamber (C4) from the second suction port (14-2) of the second compression mechanism (30). The The refrigerant sucked into the second inner cylinder chamber (C4) of the second compression mechanism (30) is compressed in the second inner cylinder chamber (C4) to become a high-pressure refrigerant. The high-pressure refrigerant flows out from the second inner cylinder chamber (C4) into the space in the casing (10) and fills the space. The high-pressure refrigerant is discharged from the second b discharge port (15-2b) and flows into the gas cooler (2). The refrigerant dissipates heat to the outdoor air by the gas cooler (2), is reduced to an intermediate pressure by the first expansion valve (5), and flows into the gas-liquid separator (4). The liquid refrigerant separated by the gas-liquid separator (4) flows out of the gas-liquid separator (4), is reduced to a low pressure by the second expansion valve (6), is evaporated by the evaporator (3), Inhaled into one compression mechanism (20).

  On the other hand, the refrigerant sucked into the second outer cylinder chamber (C3) of the second compression mechanism (30) has the second a discharge port (15-2a) set to the first by switching the three-way valve (7) to the second position. It is not compressed because it communicates with the discharge pipe (63). In other words, since the second a discharge port (15-2a) is at an intermediate pressure, the intermediate pressure refrigerant sucked into the second outer cylinder chamber (C3) is not substantially compressed, and the second a discharge port (15- Outflow (through) with intermediate pressure from 2a). By doing so, the cylinder volume (discharge volume) of the second compression mechanism (30) is smaller in the second operating state than in the first operating state.

-Effect of Reference Technology 2-
According to this reference technique 2 , the suction volume of the low-pressure refrigerant in the first operation state is the same as the suction volume of the low-pressure refrigerant in the second operation state. On the other hand, the suction volume of the intermediate pressure refrigerant in the second operation state is smaller than the suction volume of the intermediate pressure refrigerant in the first operation state.

  That is, in the first operation state and the second operation state, the low stage intake volume is the same in the first operation state and the second operation state, while the high stage intake volume is higher than that in the first operation state. However, the second operating state becomes smaller.

In this reference technique , the outer cylinder chamber (C4) of the second compression mechanism (30) is configured to allow the refrigerant to pass through in the second operating state, so two compressions are applied to one shaft (53). In the compressor (1) in which the mechanisms (20, 30) are mechanically connected, the suction volume of the low-stage compression mechanism and the suction volume of the high-stage compression mechanism in the first operation state and the second operation state are determined. The ratio can be adjusted. Therefore, by switching the volume ratio of the compression ratio in accordance with the operating conditions, it is possible to perform an operation with a high COP (coefficient of performance).

Also in this reference technique 2 , by adopting a configuration in which the refrigerant is passed through in the outer cylinder chamber of the first compression mechanism, the suction volume of the low-stage compression mechanism in the first operation state and the second operation state can be reduced. You may make it adjust the ratio of the suction | inhalation volume of a high stage side compression mechanism.

<< Reference Technology 3 of Invention >>
Reference technique 3 of the present invention shown in FIGS. 28 and 29 will be described.

In the compressor (1) of the reference technique 3 , the first suction port (14-1) includes a first a suction port (14-1a) for sucking refrigerant into the first outer cylinder chamber (C1), 1 It is comprised from the 1b suction port (14-1b) for suck | inhaling a refrigerant | coolant to an inner cylinder chamber (C2). The first discharge port (15-1) is composed of one discharge port for discharging refrigerant from both the first outer cylinder chamber (C1) and the first inner cylinder chamber (C2). The second suction port (14-2) is constituted by a single suction port for sucking refrigerant into both the second outer cylinder chamber (C3) and the second inner cylinder chamber (C4). The second discharge port (15-2) is a 1 for discharging refrigerant from both the second outer cylinder chamber (C3) and the second inner cylinder chamber (C4) through the space in the casing (10). It is comprised by the discharge port of a book.

The other configurations related to the compressor (1) are basically the same as those of the base technology .

Next, the refrigerant circuit (60) will be described. The components of the refrigerant circuit (60) are the same as in the base technology .

  The 1a suction port (14-1a) of the compressor (1) is connected to the gas side end of the evaporator (3) via a 1a suction pipe (61a) having a muffler (9). One end of the 1b suction pipe (61b) is connected to the 1b suction port (14-1b) of the compressor (1), and the other end of the 1b suction pipe (61b) is the first port of the three-way valve (7). Connected to (P1). The second port (P2) of the three-way valve (7) is connected between the 1a suction port (14-1a) and the muffler (9) in the 1a suction pipe (61a) via the connection pipe (67g). .

  The first discharge port (15-1) of the compressor (1) is connected to the refrigerant gas outlet (4a) of the gas-liquid separator (4) via the first discharge pipe (63). The outlet (4c) of the gas-liquid separator (4) is connected to the liquid side end of the evaporator (3) via a liquid pipe (66) provided with a second expansion valve (6) in the middle. Yes.

  The first discharge pipe (63) is branched into the branch pipe (68) on the way. The branch pipe (68) is connected to the second suction port (14-2) of the second compression mechanism (30) via the second suction pipe (62). The branch pipe (68) branches into a connection pipe (67h) having a muffler (9), and this connection pipe (67h) is connected to the third port (P3) of the three-way valve (7). Yes.

  The second discharge port (15-2) of the second compression mechanism (30) is connected to one end of the second discharge pipe (64), and the other end of the second discharge pipe (64) is a gas-liquid separator (4). Connected to the inlet (4b). In the middle of the second discharge pipe (64), a gas cooler (2) and a first expansion valve (5) are provided in order from the second discharge port (15-2) side.

  The three-way valve (7) switches between a first position where the first port (P1) and the second port (P2) communicate with each other and a second position where the first port (P1) and the third port (P3) communicate with each other. It is configured to be able to.

  The three-way valve (7) is a switching mechanism (volume ratio changing means) that switches the flow path of the low-pressure refrigerant, the intermediate-pressure refrigerant, and the high-pressure refrigerant with respect to the compression mechanisms (20, 30). The ratio of the suction volume of the low-stage compression mechanism and the suction volume of the high-stage compression mechanism is changed by changing the connection relationship in the refrigerant circuit (60) of (C1, C2, C3, C4). It is configured.

  The switching mechanism is configured such that when the first compression mechanism (20) is on the low stage side and the second compression mechanism (30) is on the high stage side, both cylinder chambers (C1) of the first compression mechanism (20) are provided. , C2) compresses the refrigerant to create a pressure difference between the suction side and the discharge side, and compresses the refrigerant in one cylinder chamber (C1) of the first compression mechanism (20) to compress the pressure on the suction side and the discharge side. While the difference occurs, the other cylinder chamber (C2) is configured to be able to switch between a state in which the suction side and the discharge side have substantially the same pressure and the refrigerant passes through in an uncompressed state. That is, the refrigerant is configured to pass through the other cylinder chamber (C2).

  Further, the switching mechanism (volume ratio changing means) changes the ratio of the suction volume of the low-stage compression mechanism (20) and the suction volume of the high-stage compression mechanism (30) in accordance with a change in operating conditions. It is configured.

-Driving action-
In this air conditioner, the first operating state shown in FIG. 26 and the second operating state shown in FIG. 27 can be switched in accordance with a change in operating conditions.

  In the first operating state shown in FIG. 26, the three-way valve (7) is set to the first position. When the compressor (1) is started in this state, the low-pressure gas refrigerant evaporated by exchanging heat with air in the evaporator (3) becomes the 1a suction port (14-1a) and 1b suction port of the compressor (1). (14-1b) is sucked into the first compression mechanism (20) and is compressed in the outer first cylinder chamber (C1) and the inner first cylinder chamber (C2) to become an intermediate pressure refrigerant. The intermediate pressure refrigerant merges with the refrigerant from the gas-liquid separator (4) and flows into the branch pipe (68).

  The intermediate pressure refrigerant flowing through the branch pipe (68) is sucked into the second outer cylinder chamber (C3) and the second inner cylinder chamber (C4) of the second compression mechanism (30) from the second suction port (14-2). . The intermediate pressure refrigerant sucked into the second compression mechanism (30) is compressed into the high pressure refrigerant in the second outer cylinder chamber (C3) and the second inner cylinder chamber (C4). This high-pressure refrigerant is discharged into the casing (10). That is, the high pressure refrigerant is filled in the casing (10).

  The high-pressure refrigerant filled in the casing (10) is discharged from the second discharge port (15-2). The refrigerant discharged from the second discharge port (15-2) flows into the gas cooler (2) through the second discharge pipe (64). The refrigerant dissipates heat to the outdoor air by the gas cooler (2), is reduced to an intermediate pressure by the first expansion valve (5), and flows into the gas-liquid separator (4). The liquid refrigerant separated by the gas-liquid separator (4) flows out of the gas-liquid separator (4), is reduced to a low pressure by the second expansion valve (6), is evaporated by the evaporator (3), Inhaled into one compression mechanism (20).

  In the second operating state shown in FIG. 27, the three-way valve (7) is set to the second position. When the compressor (1) is started in this state, the low-pressure gas refrigerant evaporated by exchanging heat with air in the evaporator (3) is transferred from the 1a suction port (14-1a) of the compressor (1) to the first compression mechanism. It is sucked into (20) and compressed in the outer first cylinder chamber (C1) to become an intermediate pressure refrigerant.

  The intermediate pressure refrigerant discharged from the first compression mechanism (20) merges with the refrigerant from the gas-liquid separator (4) and flows into the branch pipe (68).

  The intermediate pressure refrigerant flowing through the branch pipe (68) is also divided into the connection pipe (67h) and sucked from the 1b suction port (14-1b) into the first inner cylinder chamber (C2) of the first compression mechanism (20). Is done. Since the first discharge port (15-1) is at an intermediate pressure, the refrigerant is not substantially compressed in the first inner cylinder chamber (C2).

  On the other hand, the refrigerant sucked into the second compression mechanism (30) from the branch pipe (68) is compressed into the high pressure refrigerant in the second outer cylinder chamber (C3) and the second inner cylinder chamber (C4). The high-pressure refrigerant is discharged into the casing (10) and fills the casing (10). The high-pressure refrigerant in the casing (10) is discharged from the second discharge port (15-2) and flows into the gas cooler (2). The refrigerant dissipates heat to the outdoor air by the gas cooler (2), is reduced to an intermediate pressure by the first expansion valve (5), and flows into the gas-liquid separator (4). The liquid refrigerant separated by the gas-liquid separator (4) flows out of the gas-liquid separator (4), is reduced to a low pressure by the second expansion valve (6), is evaporated by the evaporator (3), Inhaled into one compression mechanism (20).

-Effects of Reference Technology 3-
According to the reference technique 3 , the suction volume of the intermediate pressure refrigerant in the second operation state is larger than the suction volume of the intermediate pressure refrigerant in the first operation state. On the other hand, the suction volume of the low-pressure refrigerant in the second operation state is smaller than the suction volume of the low-pressure refrigerant in the first operation state.

  In the first operation state and the second operation state, the suction volume of the low-pressure refrigerant is smaller in the second operation state than in the first operation state, while the suction volume of the intermediate-pressure refrigerant is the first operation state. It becomes the same in the operation state and the second operation state.

As described above, in this reference technique , one of the cylinder chambers (C1, C2) (inner cylinder chamber) of the first compression mechanism (20) is used through in the second operation state. In the compressor (1) in which the two compression mechanisms (20, 30) are mechanically connected to the shaft (53), the suction volume and the high suction volume of the low-stage compression mechanism in the first operation state and the second operation state are increased. The ratio of the suction volume of the stage side compression mechanism can be adjusted. Therefore, by adjusting the suction volume ratio of the compressor (1) according to the operating conditions, it is possible to perform an operation with a high COP (coefficient of performance).

<< Embodiment 3 of the Invention >>
A third embodiment of the present invention shown in FIGS. 30 to 34 will be described.

FIG. 30 is a longitudinal sectional view of a compressor (100) used in the refrigeration apparatus (air conditioning apparatus) according to Embodiment 3 , and FIG. 31 is a transverse sectional view of the compression mechanism (first compression mechanism (110)). 32 is an operation state diagram of the compression mechanism (first compression mechanism (110)). FIG. 33 is a refrigerant circuit diagram illustrating a first operation state of the air conditioner, and FIG. 34 is a refrigerant circuit diagram illustrating a second operation state. The compressor (100) is used in the refrigerant circuit of the air conditioner to compress the refrigerant sucked from the evaporator in two stages and discharge it to the condenser.

<Compressor configuration>
First, the configuration of the compressor (100) will be described. The compressor (100) is a rotary compressor, and is mechanically coupled by a single drive shaft (173) to a first compression mechanism (110), a second compression mechanism (120), and a third compression mechanism ( 130) and a fourth compression mechanism (140), and is configured to compress carbon dioxide as a refrigerant (working fluid) from a low pressure to a high pressure. The cross-sectional view and the operation state diagram of the second compression mechanism (120), the third compression mechanism (130), and the fourth compression mechanism (140) are substantially the same as those of the first compression mechanism (110). FIG. 2 shows the symbols of the second compression mechanism (120), the third compression mechanism (130), and the fourth compression mechanism (140), and details thereof are omitted. In addition, the first compression mechanism (110) and the third compression mechanism (130) are in the same phase, and the second compression mechanism (120) and the fourth compression mechanism (140) are arranged 180 degrees out of phase with each other. However, the phase difference is not shown in FIG. 2 for convenience.

  As shown in FIG. 30, the compressor (100) includes a first compression mechanism (110), a second compression mechanism (120), and a third compression mechanism that are arranged in the casing (150) in order from the bottom to the top. (130) and the fourth compression mechanism (140), and an electric motor (drive mechanism) (170) positioned above each compression mechanism (110 to 140) are housed, and are configured in a completely sealed type. Yes. In this embodiment, by changing the connection relationship of the four cylinder chambers (C1, C2, C3, C4) of each compression mechanism (110 to 140), the suction volume of the low-stage compression mechanism and the high-stage compression mechanism are changed. There is provided a volume ratio changing means described later for changing the ratio of the suction volume. And by switching the flow of the refrigerant in the refrigerant circuit (180), among the first compression mechanism (110), the second compression mechanism (120), the third compression mechanism (130), and the fourth compression mechanism (140), The combination of compression mechanisms (110 to 140) used for two-stage compression can be switched.

  The casing (150) includes a cylindrical body (151), an upper end panel (152) fixed to the upper end of the body (151), and a lower end panel fixed to the lower end of the body (151). (153). The casing (150) is provided with a suction port (154) and a discharge port (155) corresponding to each compression mechanism (110 to 140). The suction port (154) includes a first suction port (154-1) corresponding to the first compression mechanism (110), a second suction port (154-2) corresponding to the second compression mechanism (120), a third A third suction port (154-3) corresponding to the compression mechanism (130) and a fourth suction port (154-4) corresponding to the fourth compression mechanism (140) are included. The discharge port includes a first discharge port (155-1) corresponding to the first compression mechanism (110), a second discharge port (155-2) corresponding to the second compression mechanism (120), and a third compression mechanism ( 130) and a fourth discharge port (155-4) corresponding to the fourth compression mechanism (140). The casing (150) is provided with a refrigerant introduction port (156) for introducing the refrigerant flowing through the refrigerant circuit (180) into the casing (150).

  The first compression mechanism (110), the second compression mechanism (120), the third compression mechanism (130), and the fourth compression mechanism (140) are stacked on the upper and lower four stages and fixed to the casing (150). It is configured between the front head (157) and the rear head (158) below the first compression mechanism (110). Each of the compression mechanisms (110 to 140) is composed of a rotary fluid machine that is a kind of a positive displacement fluid machine.

  As described above, the first compression mechanism (110) to the fourth compression mechanism (140) are sequentially arranged from the bottom side of the casing (150) toward the upper side (motor (170) side). A middle plate (159) is provided between the compression mechanisms (110 to 140). The three rear plates (159) are sandwiched between the four compression mechanisms (110 to 140), and the rear head ( The compression mechanism (110 to 140) is configured by tightening 158) to the front head (157) with a bolt (not shown) from below. The compression mechanism (100 to 140) is positioned with respect to the casing (150) by fixing the front head (157) to the casing (150).

  The front head (157) and the rear head (158) are provided with bearings (157a, 158a), respectively. A cover plate (160) is fixed to the lower surface of the rear head (158).

  The electric motor (170) includes a stator (171) and a rotor (172). The stator (171) is disposed above the fourth compression mechanism (140), and is fixed to the body (151) of the casing (150). The rotor (172) is disposed inside the stator (171). A main shaft portion of a drive shaft (crank shaft) (173) is connected to the central portion of the rotor (172), and the drive shaft (173) is configured to rotate together with the rotor (172). The shaft center of the main shaft portion coincides with the shaft center of the casing (150).

  As shown in FIG. 31, each compression mechanism (110 to 140) includes a cylinder (111, 121, 131, 141) and a rotary piston (eccentric piston) (112, 122, 132, 142) that are both formed in an annular shape. It has. In FIG. 31, members without parentheses indicate the first compression mechanism (110), and the parentheses indicate the second compression mechanism (120) to the fourth compression. The symbol of the mechanism (140) is shown.

  Cylinder (111, 121, 131, 141) and rotary piston (112, 122, 132, 142) are rear head (158) and middle plate (159), middle plate (159) and middle plate (159), or middle plate (159) and the front head (157). The inner diameter of the cylinder (111, 121, 131, 141) is larger than the outer diameter of the rotary piston (112, 122, 132, 142). Cylinder chambers (C1, C2, C3, C4) are formed between the inner peripheral surface of the cylinder (111, 121, 131, 141) and the outer peripheral surface of the rotary piston (112, 122, 132, 142). Yes.

  On the outer peripheral surface of the rotary piston (112, 122, 132, 142), flat blades (113, 123, 133, 143) are projected. The blade (113, 123, 133, 143) has a pair of swing bushes (114, 124, 134, 144) provided swingably with respect to the cylinder (111, 121, 131, 141). It is slidably inserted. The rotary piston (112, 122, 132, 142) can swing with respect to the cylinder (111, 121, 131, 141) together with the blade (113, 123, 133, 143). The blade (113, 123, 133, 143) divides the cylinder chamber (C1, C2, C3, C4) into two.

  The eccentric portions (173a, 173b, 173c, 173d) of the drive shaft (173) are rotatably fitted inside the rotary pistons (112, 122, 132, 142). The eccentric portions (173a, 173b, 173c, 173d) have a larger diameter than the main shaft portion and are eccentric with respect to the main shaft portion. In the compression mechanism (100), when the drive shaft (173) rotates, the inner peripheral surface of the rotary piston (112, 122, 132, 142) passes through the oil film on the outer peripheral surface of the eccentric portion (173a, 173b, 173c, 173d). The rotary pistons (112, 122, 132, 142) are in sliding contact with the inner peripheral surfaces of the cylinders (111, 121, 131, 141) via an oil film while the rotary pistons (112, 122, 132, 142) are in sliding contact with the inner peripheral surfaces of the cylinders (111, 121, 131, 141). , 142) rotates eccentrically.

  Connected to the cylinder (111, 121, 131, 141) so that the suction port (154-1, 154-2, 154-3, 154-4) communicates with the cylinder chamber (C1, C2, C3, C4) Has been. The suction port (154-1, 154-2, 154-3, 154-4) is one of the swing bushes (114, 124, 134, 144) (the right swing bush (114, 124, 134 in FIG. 31)). , 144)). In the cylinder chamber (C1, C2, C3, C4), the side on which the suction port (154-1, 154-2, 154-3, 154-4) opens is the low pressure side. The “low pressure side” herein includes a low pressure side with respect to the intermediate pressure side and an intermediate pressure side with respect to the high pressure side.

  Each compression mechanism (110 to 140) has a discharge space (161, 162, etc.) and a discharge port (155-1, 155-2, 155-3) in the discharge space (161, 162, etc.). , 155-4) are connected. The discharge space (161, 162, etc.) communicates with the cylinder chamber (C1, C2, C3, C4) via the discharge port (110a, 140a, etc.). The discharge space (161, 162, etc.) is provided with a discharge valve (reed valve) (163, 164, etc.) that opens and closes the discharge port (110a, 140a, etc.) (about the second compression mechanism and the third compression mechanism) Is omitted).

  In the first compression mechanism (110) to the third compression mechanism (130), the discharge ports (155-1, 155-2, 155-3) communicate with the discharge space (161 etc.). In the fourth compression mechanism (140), the discharge port (155-4) communicates with the discharge space (162) through the space in the casing (150). The discharge ports (110a, 140a) of the first compression mechanism (110) and the fourth compression mechanism (140) are connected to the other of the swing bushes (114, 124, 134, 144) (the left swing bush (114 in FIG. 31)). , 124, 134, 144)). In the cylinder chamber (C1, C2, C3, C4), the side where the discharge port (110a, 140a, etc.) opens is the high pressure side. The “high pressure side” herein includes a high pressure side with respect to the intermediate pressure side and an intermediate pressure side with respect to the low pressure side.

  As described above, the compressor (100) includes the first compression mechanism (110), the second compression mechanism (120), and the third compression each having one cylinder chamber (C1, C2, C3, C4). A mechanism (130) and a fourth compression mechanism (140), and each compression mechanism (110 to 140) includes a cylinder (111, 121, 131, 141) having a cylindrical cylinder space, and the cylinder space. And rotary pistons (112, 122, 132, 142) (eccentric pistons) that perform eccentric rotational motion.

  In the above configuration, the first compression mechanism (110) to the fourth compression mechanism (140) have different suction volumes of the four cylinder chambers (C1, C2, C3, C4). In order to vary the suction volume of each cylinder chamber (C1, C2, C3, C4), specifically, the axial length of the rotary piston (112, 122, 132, 142) of each compression mechanism (110-140) The length dimension and the axial length dimension of the corresponding cylinder (111, 121, 131, 141) are different. In the illustrated example, the axial length of the cylinder (111) and the rotary piston (112) of the first compression mechanism (110) is the largest, and from the first compression mechanism (110) to the fourth compression mechanism (140). The cylinders (111, 121, 131, 141) and the rotary pistons (112, 122, 132, 142) are dimensioned in this order so that the axial lengths become smaller.

  An oil sump in which lubricating oil is stored is formed at the bottom of the casing (150). A centrifugal oil pump (174) immersed in an oil reservoir is provided at the lower end of the drive shaft (173). The oil pump is connected to an oil supply passage (not shown) extending in the vertical direction inside the drive shaft (173). The oil pump (174) supplies lubricating oil to the sliding portions of the first compression mechanism (110) and the second compression mechanism (120) and the bearing portion of the drive shaft (173) through the oil supply passage.

<Configuration of refrigerant circuit>
The refrigerant circuit (180) of the air conditioner performs a refrigeration cycle by compressing carbon dioxide, which is a refrigerant, to a supercritical pressure with the compressor (100), as shown in FIGS. 33 and 34. The compressor (100), the gas cooler (102), the evaporator (103), the gas-liquid separator (104), the first expansion valve (105), and the second expansion valve (106). is doing. The refrigerant circuit (180) includes a first three-way valve (switching mechanism) (107a) on the suction side of the compressor (100) and a second three-way valve (switching mechanism) on the discharge side of the compressor (100) ( 107b).

  The low-pressure refrigerant pipe (181) connected to the gas side end of the evaporator (103) branches into a first suction pipe (182a) and a second suction pipe (182b). The first suction pipe (182a) is connected to the first suction port (154-1) of the compressor (100), and the second suction pipe (182b) is connected to the second suction port (154-2). .

  A first discharge pipe (183a) is connected to the first discharge port (155-1) of the compressor (100), and a second discharge pipe (183b) is connected to the second discharge port (155-2). ing. The first discharge pipe (183a) and the second discharge pipe (183b) merge and then branch to the intermediate pressure refrigerant pipe (184) and the first connection pipe (189a). The intermediate pressure refrigerant pipe (184) is connected to the refrigerant gas outlet (104a) of the gas-liquid separator (104). The first connecting pipe (189a) is connected to the third port (P3) of the second three-way valve (107b).

  The intermediate pressure refrigerant pipe (184) branches into the branch pipe (185) on the downstream side of the refrigerant gas outlet (104a) of the gas-liquid separator (104). This branch pipe (185) is connected to the second port (P2) of the first three-way valve (107a). One end of the third suction pipe (182c) is connected to the first port (P1) of the first three-way valve (107a), and the other end is connected to the third suction port (154-3) of the compression mechanism (100). Has been. The branch pipe (185) branches to a fourth suction pipe (182d) between a connection point with the intermediate pressure refrigerant pipe (184) and a connection point with the first three-way valve (107a). The pipe (182d) is connected to the fourth suction port (154-4) of the compressor (100). The second suction pipe (182b) branches to the second connection pipe (189b) between the second suction port (154-2) and the low-pressure refrigerant pipe (181), and the second connection pipe (189b) ) Is connected to the third port (P3) of the first three-way valve (107a).

  The third discharge port (155-3) is connected to the first port (P1) of the second three-way valve (107b) via the third discharge pipe (183c). The second port (P2) of the second three-way valve (107b) is connected to the refrigerant introduction port (156) via the high-pressure refrigerant introduction pipe (186).

  The fourth discharge port (155-4) of the compressor (100) is connected to one end of a high-pressure refrigerant pipe (fourth discharge pipe) (187). The other end of the high-pressure refrigerant pipe (187) is connected to the inlet (104b) of the gas-liquid separator (104) via the gas cooler (102) and the first expansion valve (105). The outlet (104c) of the gas-liquid separator (104) is connected to the liquid side end of the evaporator (103) via a liquid pipe (188) provided with a second expansion valve (106) on the way. Yes.

  In the above configuration, the branch pipe (185) constitutes an injection mechanism (injection pipe) that injects the intermediate pressure refrigerant into the compression mechanism (110 to 140).

  Each of the three-way valves (107a, 107b) includes a first position (see FIG. 33) where the first port (P1) and the second port (P2) communicate, a first port (P1) and a third port (P3). Can be switched to the second position (see FIG. 34) where the

  The three-way valves (107a, 107b) are switching mechanisms (volume ratio changing means) that switch the flow paths of the low-pressure refrigerant, the intermediate-pressure refrigerant, and the high-pressure refrigerant with respect to the compression mechanisms (110 to 140). By changing the connection relationship of the four cylinder chambers (C1, C2, C3, C4) in (180), the ratio of the suction volume of the low-stage compression mechanism and the suction volume of the high-stage compression mechanism is changed. It is configured as follows. That is, the switching mechanism (7) can change the cylinder chamber used for the low-stage compression mechanism and the cylinder chamber used for the high-stage compression mechanism among the four cylinder chambers (C1, C2, C3, C4). It is configured to be able to.

  The switching mechanism (107a, 107b) includes the third compression mechanism (130) and the fourth compression mechanism (140) using the first compression mechanism (110) and the second compression mechanism (120) as the low-stage compression mechanism. 33 for the high-stage compression mechanism, and the fourth compression using the first compression mechanism (110), the second compression mechanism (120), and the third compression mechanism (130) for the low-stage compression mechanism. The mechanism (140) is configured to be switchable between the state shown in FIG. 34 where the high-stage compression mechanism is used.

  The switching mechanism (volume ratio changing means) (107a, 107b) is configured to change the ratio of the suction volume of the low-stage compression mechanism and the suction volume of the high-stage compression mechanism in accordance with a change in operating conditions. Has been.

-Driving action-
<Operation of compressor (100)>
The operation of the compressor (100) will be described. In the compressor (100), when the electric motor (170) is operated, the compression mechanisms (110 to 140) are driven by the rotation of the drive shaft (173), and the refrigerant is compressed by the compression mechanisms (110 to 140). Is done. In addition, since operation | movement itself of each compression mechanism (110-140) is almost the same, below, only operation | movement of a 1st compression mechanism (110) is demonstrated and description of operation | movement of another compression mechanism (120-140) is given below. Is omitted.

  The process of the refrigerant flowing into the compression mechanism (100) will be described with reference to FIG. The drive shaft (173) is slightly rotated from the state (A) where the rotation angle is 0 °, and the contact position between the first rotary piston (112) and the first cylinder (111) is changed to the first suction port (154-1). ) Starts to flow into the first cylinder chamber (C1) from the first suction port (154-1). The refrigerant flows into the first cylinder chamber (C1) as the rotation angle of the drive shaft (173) increases to 90 ° in (B), 180 ° in (C), and 270 ° in (D). The refrigerant continues to flow until the rotation angle reaches 360 ° (0 °) of (A).

  Subsequently, a process of compressing the refrigerant by the first compression mechanism (110) will be described. In a state where the inflow of the refrigerant into the first cylinder chamber (C1) has been completed (rotation angle 360 ° (0 °) of the drive shaft (173)), the drive shaft (173) is slightly changed from the state where the rotation angle is 0 ° again. , The contact position between the first rotary piston (112) and the first cylinder (111) passes through the opening of the first suction port (154-1). In the first compression mechanism (110), when the contact position passes through the opening of the first suction port (154-1), the refrigerant compression in the first compression mechanism (110) is completed. When the drive shaft (173) further rotates from this state, the refrigerant starts to be compressed. When the refrigerant pressure in the first cylinder chamber (C1) exceeds the refrigerant pressure outside the discharge port (110a), the discharge is started. The valve (163) is opened, and the refrigerant is discharged from the second outlet (110a) to the outside of the cylinder chamber (C1). The discharge of the refrigerant continues until the rotation angle of the drive shaft (173) reaches 360 °.

<Operation of air conditioner>
In this air conditioner, the first operating state shown in FIG. 33 and the second operating state shown in FIG. 34 can be switched in accordance with changes in operating conditions. In the following description, it is assumed that the operation is a cooling operation.

  In the first operating state shown in FIG. 34, both the first three-way valve (107a) and the second three-way valve (107b) are set to the first position. When the compressor (100) is started in this state, the low-pressure gas refrigerant evaporated by exchanging heat with air in the evaporator (103) passes from the low-pressure refrigerant pipe (181) to the first suction pipe (182a) and the second suction pipe ( 182b), from the first suction pipe (182a) through the first suction port (154-1) to the first compression mechanism (110), and from the second suction pipe (182b) to the second suction port ( 154-2) and sucked into the second compression mechanism (120). The refrigerant is compressed in the first cylinder chamber (C1) and the second cylinder chamber (C2) to become an intermediate pressure refrigerant.

  The intermediate pressure refrigerant discharged from the cylinder chambers (C1, C2) passes through the first discharge pipe (183a) and the second discharge pipe (183b), and then merges in the intermediate pressure refrigerant pipe (184). The intermediate pressure refrigerant from the separator (104) joins and flows into the branch pipe (185). The intermediate pressure refrigerant flowing through the branch pipe (185) is divided into the third suction pipe (182c) and the fourth suction pipe (182d). The intermediate pressure refrigerant passes from the third suction pipe (182c) through the third suction port (154-3) to the third compression mechanism (130), and from the fourth suction pipe (182d) to the fourth suction port (154). -4) and is sucked into the fourth compression mechanism (140). The refrigerant is compressed in the third cylinder chamber (C3) and the fourth cylinder chamber (C4) to become a high-pressure refrigerant.

  The high-pressure refrigerant discharged from the third discharge port (155-3) passes through the second three-way valve (107b) and the high-pressure refrigerant introduction pipe (186) from the refrigerant introduction port (156) to the casing ( 150). On the other hand, the high-pressure refrigerant compressed in the fourth cylinder chamber (C4) flows out from the discharge space (162) of the front head (157) into the space in the casing (150). Therefore, the high-pressure refrigerant compressed in the third cylinder chamber (C3) and the high-pressure refrigerant compressed in the fourth cylinder chamber (C4) merge in the casing (150).

  The high-pressure refrigerant in the casing (150) is discharged from the casing (150) through the fourth discharge port (155-4), and flows into the gas cooler (102) through the high-pressure refrigerant pipe (187). The refrigerant radiates heat to the outdoor air by the gas cooler (102), is then reduced to an intermediate pressure by the first expansion valve (105), and flows into the gas-liquid separator (104). The refrigerant is gas-liquid separated by the gas-liquid separator (104), and the liquid refrigerant flows out of the gas-liquid separator (104). The liquid refrigerant is depressurized to a low pressure by the second expansion valve (106), then evaporated by the evaporator (103), and sucked into the first compression mechanism (110) and the second compression mechanism (120). The gas refrigerant in the gas-liquid separator (104) is introduced into the third compression mechanism (130) and the fourth compression mechanism (140).

  In the second operating state shown in FIG. 34, both the first three-way valve (107a) and the second three-way valve (107b) are set to the second position. When the compressor (100) is started in this state, the low-pressure gas refrigerant evaporated by exchanging heat with air in the evaporator (103) passes from the low-pressure refrigerant pipe (181) to the first suction pipe (182a) and the second suction pipe ( 182b) and the third suction pipe (182c). The refrigerant passes from the first suction pipe (182a) through the first suction port (154-1) to the first compression mechanism (110), and from the second suction pipe (182b) to the second suction port (154). -2) is sucked into the second compression mechanism (120) and from the third suction pipe (182c) through the third suction port (154-3) into the third compression mechanism (130). The refrigerant is compressed into an intermediate pressure refrigerant in the first cylinder chamber (C1), the second cylinder chamber (C2), and the third cylinder chamber (C3).

  The intermediate pressure refrigerant discharged from each cylinder chamber (C1, C2, C3) passes through the first discharge pipe (183a), the second discharge pipe (183b), and the third discharge pipe (183c), respectively, and then the intermediate pressure refrigerant. It merges in the pipe (184), and further merges with the intermediate pressure refrigerant from the gas-liquid separator (104) and flows into the branch pipe (185). The intermediate pressure refrigerant flowing through the branch pipe (185) flows into the fourth suction pipe (182d). The intermediate pressure refrigerant is sucked from the fourth suction pipe (182d) through the fourth suction port (154-4) into the fourth compression mechanism (140). The refrigerant is compressed in the fourth cylinder chamber (C4) to become a high-pressure refrigerant.

  The high-pressure refrigerant compressed in the fourth cylinder chamber (C4) flows out from the discharge space (162) of the front head (157) into the space in the casing (150). The high-pressure refrigerant in the casing (150) is discharged from the casing (150) through the fourth discharge port (155-4), and flows into the gas cooler (102) through the high-pressure refrigerant pipe (187). The refrigerant radiates heat to the outdoor air by the gas cooler (102), is then reduced to an intermediate pressure by the first expansion valve (105), and flows into the gas-liquid separator (104). The refrigerant is gas-liquid separated by the gas-liquid separator (104), and the liquid refrigerant flows out of the gas-liquid separator (104). The liquid refrigerant is depressurized to a low pressure by the second expansion valve (106), then evaporated by the evaporator (103), and sucked into the first compression mechanism (110) and the second compression mechanism (120). The gas refrigerant in the gas-liquid separator (104) is introduced into the fourth compression mechanism (140).

-Effect of Embodiment 3-
According to this embodiment, the suction volume of the low-pressure refrigerant in the second operation state is larger than the suction volume of the low-pressure refrigerant in the first operation state. Further, the suction volume of the intermediate pressure refrigerant in the second operation state is smaller than the suction volume of the intermediate pressure refrigerant in the first operation state.

  That is, in the first operation state and the second operation state, the low stage intake amount is larger in the second operation state than in the first operation state, while the high stage intake amount is in the first operation state. The second operation state is less than the second operation state.

  As described above, in this embodiment, the cylinder chambers (C1, C2, C3, C4) of the compression mechanisms (110 to 140) are used in combination in the first operation state and the second operation state. In the compressor (100) in which four compression mechanisms (110 to 140) are mechanically connected to one shaft, the suction volume of the low-stage compression mechanism in the first operation state and the second operation state The ratio of the suction volume of the high stage side compression mechanism can be adjusted. Thus, by adjusting the ratio of the suction volume in the compressor (100) according to the operating conditions, it becomes possible to perform an operation with a high COP (coefficient of performance). In addition, torque fluctuations associated with refrigerant compression can be adjusted.

  Note that, for example, in the two-stage compression mechanism, it is possible to adjust the suction volume ratio by unloading on the low stage side or the high stage side. However, in this embodiment, unlike the above, the refrigerant is compressed from the middle. Since it is not configured to perform, smooth operation can be performed.

<< Embodiment 4 of the Invention >>
Embodiment 4 shown in FIGS. 35 and 36 will be described.

In this embodiment, the structure of the compressor (100) is the same as that of the third embodiment, and the configuration of the refrigerant circuit (180) is different from that of the third embodiment . Therefore, only the refrigerant circuit (180) will be described below. The components of the refrigerant circuit (180) are the same as those in the third embodiment .

  As shown in FIGS. 35 and 36, the low pressure refrigerant pipe (181) connected to the gas side end of the evaporator (103) is connected to the first suction port (154-1) via the first suction pipe (182a). It is connected to the. The low-pressure refrigerant pipe (181) branches to the connection pipe (189c) on the outlet side of the evaporator (103), and the connection pipe (189c) is connected to the second port (P2) of the first three-way valve (107a). Has been. One end of the third suction pipe (182c) is connected to the first port (P1) of the first three-way valve (107a), and the other end of the third suction pipe (182c) is connected to the third suction port (154-3). It is connected.

  A first discharge pipe (183a) is connected to the first discharge port (155-1) of the compressor (100). The first discharge pipe (183a) is connected to one end of the intermediate pressure refrigerant pipe (184), and the other end of the intermediate pressure refrigerant pipe (184) is connected to the refrigerant gas outlet (104a) of the gas-liquid separator (104). ing. One end of the third discharge pipe (183c) is connected to the third discharge port (155-3), and the other end of the third discharge pipe (183c) is connected to the first port (P1) of the second three-way valve (107b). )It is connected to the. One end of the connection pipe (189d) is connected to the second port (P2) of the second three-way valve (107b), and the other end of the connection pipe (189d) joins the first discharge pipe (183a) to generate an intermediate pressure refrigerant. Connected to tube (184).

  The intermediate pressure refrigerant pipe (184) branches to the first branch pipe (185) on the downstream side of the refrigerant gas outlet (104a) of the gas-liquid separator (104). The branch pipe (185) is connected to the third port (P3) of the first three-way valve (107a). The branch pipe (185) branches to the second branch pipe (185b) between the connection point with the intermediate pressure refrigerant pipe (184) and the connection point with the first three-way valve (107a). The branch pipe (185b) further branches into a second suction pipe (182b) and a fourth suction pipe (182d). The second suction pipe (182b) is connected to the second suction port (154-2) of the compressor (100), and the fourth suction pipe (182d) is connected to the fourth suction port (154-4).

  The third port (P3) of the second three-way valve (107b) is connected to the refrigerant introduction port (156) via the high-pressure refrigerant introduction pipe (186). One end of the second discharge pipe (183b) is connected to the second discharge port (155-2), and the other end of the second discharge pipe (183b) is connected to the high-pressure refrigerant introduction pipe (186). .

  One end of a high-pressure refrigerant pipe (187) is connected to the fourth discharge port (155-4) of the compressor (100). The other end of the high-pressure refrigerant pipe (187) is connected to the inlet (104b) of the gas-liquid separator (104) via the gas cooler (102) and the first expansion valve (105). The outlet (104c) of the gas-liquid separator (104) is connected to the liquid side end of the evaporator (103) via a liquid pipe (188) provided with a second expansion valve (106) on the way. Yes.

  In the above configuration, the branch pipe (185) constitutes an injection mechanism for injecting the intermediate pressure refrigerant into the compression mechanism (110 to 140).

  Each of the three-way valves (107a, 107b) includes a first position (see FIG. 35) where the first port (P1) and the second port (P2) communicate with each other, a first port (P1) and a third port (P3). Can be switched to the second position (see FIG. 36) where the

  The three-way valves (107a, 107b) are switching mechanisms (volume ratio changing means) that switch the flow paths of the low-pressure refrigerant, the intermediate-pressure refrigerant, and the high-pressure refrigerant with respect to the compression mechanisms (110 to 140). By changing the connection relationship of the four cylinder chambers (C1, C2, C3, C4) in (180), the ratio of the suction volume of the low-stage compression mechanism and the suction volume of the high-stage compression mechanism is changed. It is configured as follows.

  The switching mechanism (107a, 107b) uses the first compression mechanism (110) and the third compression mechanism (130) as the low-stage compression mechanism, and the second compression mechanism (120) and the fourth compression mechanism (140). 35) for the high-stage compression mechanism, and the second compression mechanism (120), the third compression mechanism (130), and the fourth compression using the first compression mechanism (110) for the low-stage compression mechanism. The mechanism (140) is configured to be switchable between the state shown in FIG. 36 where the high-stage compression mechanism is used.

  Further, the switching mechanism (volume ratio changing means) (107a, 107b) is configured to change the ratio of the suction volume of the low-stage side compression mechanism and the suction volume of the high-stage side compression mechanism in accordance with a change in operating conditions. Has been.

-Driving action-
Also in this air conditioner, the first operating state shown in FIG. 35 and the second operating state shown in FIG. 36 can be switched in accordance with changes in the operating conditions.

  In the first operating state shown in FIG. 35, both the first three-way valve (107a) and the second three-way valve (107b) are set to the first position. When the compressor (100) is started in this state, the low-pressure gas refrigerant evaporated by exchanging heat with air in the evaporator (103) passes from the low-pressure refrigerant pipe (181) to the first suction pipe (182a) and the third suction pipe ( 182c), from the first suction pipe (182a) through the first suction port (154-1) to the first compression mechanism (110), and from the third suction pipe (182c) to the third suction port ( 154-3) and sucked into the third compression mechanism (130). The refrigerant is compressed in the first cylinder chamber (C1) and the third cylinder chamber (C3) to become an intermediate pressure refrigerant.

  The intermediate pressure refrigerant discharged from the first cylinder chamber (C1) flows through the first discharge pipe (183a), and the intermediate pressure refrigerant discharged from the third cylinder chamber (C3) is second from the third discharge pipe (183c). The refrigerant flows through the three-way valve (107b) and the connecting pipe (189d), and these refrigerants merge at the intermediate pressure refrigerant pipe (184). The intermediate pressure refrigerant merges with the intermediate pressure refrigerant from the gas-liquid separator (104) and flows into the first branch pipe (185). The intermediate pressure refrigerant is further diverted from the first branch pipe (185) to the second branch pipe (185b). Then, the air is sucked into the second compression mechanism (120) from the second suction pipe (182b) through the second suction port (154-2), and from the fourth suction pipe (182d) to the fourth suction port (154- It is sucked into the fourth compression mechanism (140) through 4). The refrigerant is compressed in the second cylinder chamber (C2) and the fourth cylinder chamber (C4) to become a high-pressure refrigerant.

  The high pressure refrigerant discharged from the second discharge port (155-2) passes from the second discharge pipe (183b) through the high pressure refrigerant introduction pipe (186) to the casing of the compressor (100) from the refrigerant introduction port (156). 150). On the other hand, the high-pressure refrigerant compressed in the fourth cylinder chamber (C4) flows out from the discharge space (162) of the front head (157) into the space in the casing (150). Therefore, the high-pressure refrigerant compressed in the second cylinder chamber (C2) and the high-pressure refrigerant compressed in the fourth cylinder chamber (C4) merge in the casing (150).

The high-pressure refrigerant in the casing (150) is discharged from the casing (150) through the fourth discharge port (155-4),
It flows into the gas cooler (102) through the high-pressure refrigerant pipe (fourth discharge pipe) (187). The refrigerant radiates heat to the outdoor air by the gas cooler (102), is then reduced to an intermediate pressure by the first expansion valve (105), and flows into the gas-liquid separator (104). The refrigerant is gas-liquid separated by the gas-liquid separator (104), and the liquid refrigerant flows out of the gas-liquid separator (104). The liquid refrigerant is depressurized to a low pressure by the second expansion valve (106), then evaporated by the evaporator (103), and sucked into the first compression mechanism (110) and the third compression mechanism (130). The gas refrigerant in the gas-liquid separator (104) is introduced into the second compression mechanism (120) and the fourth compression mechanism (140).

  In the second operating state shown in FIG. 36, both the first three-way valve (107a) and the second three-way valve (107b) are set to the second position. When the compressor (100) is started in this state, the low-pressure gas refrigerant evaporated by exchanging heat with air in the evaporator (103) flows from the low-pressure refrigerant pipe (181) into the first suction pipe (182a), and the first The air is sucked into the first compression mechanism (110) from the suction pipe (182a) through the first suction port (154-1). The refrigerant is compressed in the first cylinder chamber (C1) to become an intermediate pressure refrigerant.

  The intermediate pressure refrigerant discharged from the first cylinder chamber (C1) is discharged from the first discharge pipe (183a) and flows through the intermediate pressure refrigerant pipe (184), and the intermediate pressure refrigerant from the gas-liquid separator (104) Merge and flow into the first branch pipe (185). The intermediate pressure refrigerant flowing through the first branch pipe (185) is divided into the second suction pipe (182b), the third suction pipe (182c), and the fourth suction pipe (182d), and from the second suction pipe (182b). Passes through the second suction port (154-2) to the second compression mechanism (120), and from the third suction pipe (182c) through the third suction port (154-3) to the third compression mechanism (130). And from the fourth suction pipe (182d) through the fourth suction port (154-4) to the fourth compression mechanism (140). The refrigerant is compressed in the second cylinder chamber (C2), the third cylinder chamber (C3), and the fourth cylinder chamber (C4) to become a high-pressure refrigerant.

  The high-pressure refrigerant compressed in the second cylinder chamber (C2) is discharged from the second discharge port (155-2) and flows through the second discharge pipe (183b) toward the refrigerant introduction port (156). On the other hand, the high-pressure refrigerant compressed in the third cylinder chamber (C3) is discharged from the third discharge port (155-3), and the third discharge pipe (183c) and the high-pressure refrigerant introduction pipe (186) are connected to the refrigerant introduction port (156 ) The high-pressure refrigerant discharged from the second cylinder chamber (C2) and the high-pressure refrigerant discharged from the third cylinder chamber (C3) merge at the high-pressure refrigerant introduction pipe (186), and the casing (150) from the refrigerant introduction port (156) Flows in.

  The high-pressure refrigerant compressed in the fourth cylinder chamber (C4) flows out from the discharge space (162) of the front head (157) into the space in the casing (150). In the casing (150), the high-pressure refrigerant discharged from the second cylinder chamber (C2) and the third cylinder chamber (C3) and the high-pressure refrigerant discharged from the fourth cylinder chamber (C4) are mixed. Then, the high-pressure refrigerant in the casing (150) is discharged from the casing (150) through the fourth discharge port (155-4), passes through the high-pressure refrigerant pipe (fourth discharge pipe) (187), and the gas cooler (102 ). The refrigerant radiates heat to the outdoor air by the gas cooler (102), is then reduced to an intermediate pressure by the first expansion valve (105), and flows into the gas-liquid separator (104). The refrigerant is gas-liquid separated by the gas-liquid separator (104), and the liquid refrigerant flows out of the gas-liquid separator (104). The liquid refrigerant is reduced to a low pressure by the second expansion valve (106), then evaporated by the evaporator (103), and sucked into the first compression mechanism (110). The gas refrigerant in the gas-liquid separator (104) is introduced into the second compression mechanism (120), the third compression mechanism (130), and the fourth compression mechanism (140).

-Effect of Embodiment 4-
According to this embodiment, the suction volume of the low-pressure refrigerant in the second operation state is smaller than the suction volume of the low-pressure refrigerant in the first operation state. Further, the suction volume of the intermediate pressure refrigerant in the second operation state is larger than the suction volume of the intermediate pressure refrigerant in the first operation state.

  That is, in the first operation state and the second operation state, the low stage intake amount is smaller in the second operation state than in the first operation state, while the high stage intake amount is in the first operation state. More in the second operating state than in the second operating state.

  As described above, in this embodiment, the cylinder chambers (C1, C2, C3, C4) of the compression mechanisms (110 to 140) are used in combination in the first operation state and the second operation state. In the compressor (100) in which four compression mechanisms (110 to 140) are mechanically connected to one shaft, the suction volume of the low-stage compression mechanism in the first operation state and the second operation state The ratio of the suction volume of the high stage side compression mechanism can be adjusted. Thus, by switching the volume ratio of the compressor (100) in accordance with the operating conditions, it is possible to perform an operation with a high COP (coefficient of performance). In addition, torque fluctuations associated with refrigerant compression can be adjusted.

<< Embodiment 5 of the Invention >>
Embodiment 5 shown in FIGS. 37 and 38 will be described.

In the fifth embodiment, the structure of the compressor (100) is the same as that of the third embodiment, and the configuration of the refrigerant circuit (180) is different from that of the third embodiment . Therefore, only the refrigerant circuit (180) will be described below. In this embodiment, among the components of the refrigerant circuit (180), four-way switching valves (108a, 108b) are used instead of the three-way valves (107a, 107b).

  As shown in FIGS. 37 and 38, the low-pressure refrigerant pipe (181) connected to the gas side end of the evaporator (103) is connected to the first suction port (154-1) via the first suction pipe (182a). It is connected to the. The low-pressure refrigerant pipe (181) branches to the connection pipe (189e) on the outlet side of the evaporator (103), and the connection pipe (189e) is the second port (P2) of the first four-way switching valve (108a). It is connected to the. One end of the second suction pipe (182b) is connected to the first port (P1) of the first four-way switching valve (108a), and the other end of the second suction pipe (182b) is connected to the second suction port (154-2). )It is connected to the.

  A first discharge pipe (183a) is connected to the first discharge port (155-1) of the compressor (100), and a second discharge pipe (183b) is connected to the second discharge port (155-2). ing. The first discharge pipe (183a) is connected to one end of the intermediate pressure refrigerant pipe (184), and the other end of the intermediate pressure refrigerant pipe (184) is connected to the refrigerant gas outlet (104a) of the gas-liquid separator (104). ing. The second discharge pipe (183b) is connected to the first port (P1) of the second four-way switching valve (108b). The first discharge pipe (183a) branches to a connection pipe (189f), and the connection pipe (189f) is connected to the second port (P2) of the second four-way switching valve (108b).

  The intermediate pressure refrigerant pipe (184) branches into the branch pipe (185) on the downstream side of the refrigerant gas outlet (104a) of the gas-liquid separator (104). The branch pipe (185) is connected to the fourth port (P4) of the first four-way switching valve (108a). One end of the third suction pipe (182c) is connected to the third port (P3) of the first four-way selector valve (108a), and the other end is connected to the third suction port (154-3) of the compression mechanism. ing. The branch pipe (185) branches to a fourth suction pipe (182d) between a connection point with the intermediate pressure refrigerant pipe (184) and a connection point with the first four-way switching valve (108a). A four suction pipe (182d) is connected to the fourth suction port (154-4) of the compressor (100).

  The third discharge port (155-3) is connected to the third port (P3) of the second four-way switching valve (108b) via the third discharge pipe (183c). The fourth port (P4) of the second four-way selector valve (108b) is connected to the refrigerant introduction port (156) via the high-pressure refrigerant introduction pipe (186).

  One end of a high-pressure refrigerant pipe (187) is connected to the fourth discharge port (155-4) of the compressor (100). The other end of the high-pressure refrigerant pipe (187) is connected to the inlet (104b) of the gas-liquid separator (104) via the gas cooler (102) and the first expansion valve (105). The outlet (104c) of the gas-liquid separator (104) is connected to the liquid side end of the evaporator (103) via a liquid pipe (188) provided with a second expansion valve (106) on the way. Yes.

  In the above configuration, the branch pipe (185) constitutes an injection mechanism for injecting the intermediate pressure refrigerant into the compression mechanism (110 to 140).

  Each of the four-way selector valves (108a, 108b) has a first position (P1) and a second port (P2) communicating with each other and a third port (P3) and a fourth port (P4) communicating with each other. 37) and the second position (see FIG. 38) where the first port (P1) and the fourth port (P4) communicate with each other and the second port (P2) and the third port (P3) communicate with each other. It is configured to be able to.

  Each of the four-way switching valves (108a, 108b) is a switching mechanism (volume ratio changing means) that switches the flow paths of the low-pressure refrigerant, the intermediate-pressure refrigerant, and the high-pressure refrigerant with respect to the compression mechanisms (110 to 140). By changing the connection relationship of the four cylinder chambers (C1, C2, C3, C4) in the refrigerant circuit (180), the ratio between the suction volume of the low-stage compression mechanism and the suction volume of the high-stage compression mechanism Is configured to change.

  The switching mechanism (108a, 108b) includes the third compression mechanism (130) and the fourth compression mechanism (140) using the first compression mechanism (110) and the second compression mechanism (120) as the low-stage compression mechanism. ) For the high-stage compression mechanism, and the second compression mechanism (120) and the fourth compression mechanism (140) using the first compression mechanism (10) and the third compression mechanism (130) for the low-stage compression mechanism. ) Can be switched to the state used for the high-stage compression mechanism.

  Further, the switching mechanism (volume ratio changing means) (108a, 108b) is configured to change the ratio of the suction volume of the low-stage compression mechanism and the suction volume of the high-stage compression mechanism in accordance with a change in operating conditions. Has been.

-Driving action-
Also in this air conditioner, the first operating state shown in FIG. 37 and the second operating state shown in FIG. 38 can be switched in accordance with a change in operating conditions.

  In the first operating state shown in FIG. 37, both the first four-way switching valve (108a) and the second four-way switching valve (108b) are set to the first position. When the compressor (100) is started in this state, the low-pressure gas refrigerant evaporated by exchanging heat with air in the evaporator (103) passes from the low-pressure refrigerant pipe (181) to the first suction pipe (182a) and the second suction pipe ( 182b), from the first suction pipe (182a) through the first suction port (154-1) to the first compression mechanism (110), and from the second suction pipe (182b) to the second suction port ( 154-2) and sucked into the second compression mechanism (120). The refrigerant is compressed in the first cylinder chamber (C1) and the second cylinder chamber (C2) to become an intermediate pressure refrigerant.

  The intermediate pressure refrigerant discharged from the cylinder chambers (C1, C2) passes through the first discharge pipe (183a) and the second discharge pipe (183b), and then merges in the intermediate pressure refrigerant pipe (184). The intermediate pressure refrigerant from the liquid separator (104) joins and flows into the branch pipe (185). The intermediate pressure refrigerant flowing through the branch pipe (185) is divided into the third suction pipe (182c) and the fourth suction pipe (182d). The intermediate pressure refrigerant passes from the third suction pipe (182c) through the third suction port (154-3) to the third compression mechanism (130), and from the fourth suction pipe (182d) to the fourth suction port (154). -4) and is sucked into the fourth compression mechanism (140). The refrigerant is compressed in the third cylinder chamber (C3) and the fourth cylinder chamber (C4) to become a high-pressure refrigerant.

  The high-pressure refrigerant discharged from the third discharge port (155-3) passes through the second four-way switching valve (108b) and the high-pressure refrigerant introduction pipe (186) from the refrigerant introduction port (156) to the compressor (100). It is introduced into the casing (150). On the other hand, the high-pressure refrigerant compressed in the fourth cylinder chamber (C4) flows out from the discharge space (162) of the front head (157) into the space in the casing (150). Therefore, the high-pressure refrigerant compressed in the third cylinder chamber (C3) and the high-pressure refrigerant compressed in the fourth cylinder chamber (C4) merge in the casing (150).

  The high-pressure refrigerant in the casing (150) is discharged from the casing (150) through the fourth discharge port (155-4) and passes through the high-pressure refrigerant pipe (fourth discharge pipe) (187) to the gas cooler (102). Inflow. The refrigerant radiates heat to the outdoor air by the gas cooler (102), is then reduced to an intermediate pressure by the first expansion valve (105), and flows into the gas-liquid separator (104). The refrigerant is gas-liquid separated by the gas-liquid separator (104), and the liquid refrigerant flows out of the gas-liquid separator (104). The liquid refrigerant is depressurized to a low pressure by the second expansion valve (106), then evaporated by the evaporator (103), and sucked into the first compression mechanism (110) and the second compression mechanism (120). The gas refrigerant in the gas-liquid separator (104) is introduced into the third compression mechanism (130) and the fourth compression mechanism (140).

  In the second operating state shown in FIG. 38, both the first four-way switching valve (108a) and the second four-way switching valve (108b) are set to the second position. When the compressor (100) is started in this state, the low-pressure gas refrigerant evaporated by exchanging heat with air in the evaporator (103) passes from the low-pressure refrigerant pipe (181) to the first suction pipe (182a) and the third suction pipe ( 182c), from the first suction pipe (182a) through the first suction port (154-1) to the first compression mechanism (110), and from the third suction pipe (182c) to the third suction port ( 154-3) and sucked into the third compression mechanism (130). The refrigerant is compressed in the first cylinder chamber (C1) and the third cylinder chamber (C3) to become an intermediate pressure refrigerant.

  The intermediate pressure refrigerant discharged from each cylinder chamber (C1, C3) passes through the first discharge pipe (183a) and the third discharge pipe (183c), and then merges in the intermediate pressure refrigerant pipe (184). The intermediate pressure refrigerant from the liquid separator (104) joins and flows into the branch pipe (185). The intermediate pressure refrigerant flowing through the branch pipe (185) is divided into the second suction pipe (182b) and the fourth suction pipe (182d). The intermediate pressure refrigerant passes from the second suction pipe (182b) to the second compression mechanism (120) through the second suction port (154-2), and from the fourth suction pipe (182d) to the fourth suction port (154). -4) and is sucked into the fourth compression mechanism (140). The refrigerant is compressed in the second cylinder chamber (C2) and the fourth cylinder chamber (C4) to become a high-pressure refrigerant.

  The high-pressure refrigerant discharged from the second discharge port (155-2) passes through the second four-way switching valve (108b) and the high-pressure refrigerant introduction pipe (186) from the refrigerant introduction port (156) to the compressor (100). It is introduced into the casing (150). On the other hand, the high-pressure refrigerant compressed in the fourth cylinder chamber (C4) flows out from the discharge space (162) of the front head (157) into the space in the casing (150). Therefore, the high-pressure refrigerant compressed in the second cylinder chamber (C2) and the high-pressure refrigerant compressed in the fourth cylinder chamber (C4) merge in the casing (150).

  The high-pressure refrigerant in the casing (150) is discharged from the casing (150) through the fourth discharge port (155-4) and passes through the high-pressure refrigerant pipe (fourth discharge pipe) (187) to the gas cooler (102). Inflow. The refrigerant radiates heat to the outdoor air by the gas cooler (102), is then reduced to an intermediate pressure by the first expansion valve (105), and flows into the gas-liquid separator (104). The refrigerant is gas-liquid separated by the gas-liquid separator (104), and the liquid refrigerant flows out of the gas-liquid separator (104). The liquid refrigerant is depressurized to a low pressure by the second expansion valve (106), then evaporated by the evaporator (103), and sucked into the first compression mechanism (110) and the third compression mechanism (130). The gas refrigerant in the gas-liquid separator (104) is introduced into the second compression mechanism (120) and the fourth compression mechanism (140).

-Effect of Embodiment 5-
According to the fifth embodiment , the suction volume of the low-pressure refrigerant in the second operation state is smaller than the suction volume of the low-pressure refrigerant in the first operation state. Further, the suction volume of the intermediate pressure refrigerant in the second operation state is larger than the suction volume of the intermediate pressure refrigerant in the first operation state.

  That is, in the first operation state and the second operation state, the low stage intake amount is smaller in the second operation state than in the first operation state, while the high stage intake amount is in the first operation state. More in the second operating state than in the second operating state.

  As described above, in this embodiment, the cylinder chambers (C1, C2, C3, C4) of the compression mechanisms (110 to 140) are used in combination in the first operation state and the second operation state. In the compressor (100) in which four compression mechanisms (110 to 140) are mechanically connected to one shaft, the suction volume of the low-stage compression mechanism in the first operation state and the second operation state The ratio of the suction volume of the high stage side compression mechanism can be adjusted. Thus, by switching the volume ratio of the compressor (100) in accordance with the operating conditions, it is possible to perform an operation with a high COP (coefficient of performance). In addition, torque fluctuations associated with refrigerant compression can be adjusted.

<< Reference Technology 4 of Invention >>
Reference technique 4 shown in FIGS. 39 and 40 will be described.

In this reference technology 4 , the structure of the compressor (100) is the same as that of the third embodiment, and the configuration of the refrigerant circuit (180) is different from that of the third embodiment . Therefore, only the refrigerant circuit (180) will be described below. Note that this embodiment is different from the base technology in that among the components of the refrigerant circuit (180), a three-way valve or a four-way switching valve is not used on the suction side of the compressor (100).

  As shown in FIGS. 39 and 40, the low-pressure refrigerant pipe (181) connected to the gas side end of the evaporator (103) branches into a first suction pipe (182a) and a second suction pipe (182b). Yes. The first suction pipe (182a) is connected to the first suction port (154-1) of the compressor (100), and the second suction pipe (182b) is connected to the second suction port (154-2). .

  A first discharge pipe (183a) is connected to the first discharge port (155-1) of the compressor (100), and a second discharge pipe (183b) is connected to the second discharge port (155-2). ing. The first discharge pipe (183a) and the second discharge pipe (183b) are joined and then connected to the intermediate pressure refrigerant pipe (184). The intermediate pressure refrigerant pipe (184) is connected to the refrigerant gas outlet (104a) of the gas-liquid separator (104). The second discharge pipe (183b) branches to the connection pipe (189g). The connecting pipe (189g) is connected to the third port (P3) of the three-way valve (107).

  The intermediate pressure refrigerant pipe (184) branches into the branch pipe (185) on the downstream side of the refrigerant gas outlet (104a) of the gas-liquid separator (104). The branch pipe (185) branches into a third suction pipe (182c) and a fourth suction pipe (182d). The third suction pipe (182c) is connected to the third suction port (154-3) of the third compression mechanism (130). The fourth suction pipe (182d) is connected to the fourth suction port (154-4) of the compressor (100).

  The third discharge port (155-3) is connected to the first port (P1) of the three-way valve (107) via the third discharge pipe (183c). The second port (P2) of the three-way valve (107) is connected to the refrigerant introduction port (156) via the high-pressure refrigerant introduction pipe (186).

  One end of a high-pressure refrigerant pipe (187) is connected to the fourth discharge port (155-4) of the compressor (100). The other end of the high-pressure refrigerant pipe (187) is connected to the inlet (104b) of the gas-liquid separator (104) via the gas cooler (102) and the first expansion valve (105). The outlet (104c) of the gas-liquid separator (104) is connected to the liquid side end of the evaporator (103) via a liquid pipe (188) provided with a second expansion valve (106) on the way. Yes.

  In the above configuration, the branch pipe (185) constitutes an injection mechanism for injecting the intermediate pressure refrigerant into the compression mechanism (110 to 140).

  In the three-way valve (107), the first position (see FIG. 39) where the first port (P1) and the second port (P2) communicate with each other, and the first port (P1) and the third port (P3) communicate with each other. It can be switched to the second position (see FIG. 40).

  The three-way valve (107) is a switching mechanism (volume ratio changing means) that switches the flow paths of the low-pressure refrigerant, the intermediate-pressure refrigerant, and the high-pressure refrigerant with respect to the compression mechanisms (110 to 140). ) To change the ratio of the suction volume of the low-stage compression mechanism and the suction volume of the high-stage compression mechanism by changing the connection relationship of the four cylinder chambers (C1, C2, C3, C4) It is configured.

  In the switching mechanism (107), the first compression mechanism (110) and the second compression mechanism (120) are on the low stage side, and the third compression mechanism (130) and the fourth compression mechanism (140) are on the high stage side. When the refrigerant is compressed by both the third compression mechanism (130) and the fourth compression mechanism (140), a pressure difference occurs between the suction side and the discharge side, and the third compression mechanism (130) and the second compression mechanism (130) The refrigerant is compressed by one of the four compression mechanisms (140) (fourth compression mechanism (140)) to generate a pressure difference between the suction side and the discharge side, while the other (third compression mechanism (130)) discharges from the suction side. It is configured to be able to switch between a state in which the pressure is substantially the same on the side and the refrigerant passes without being compressed.

  The switching mechanism (volume ratio changing means) (107) is configured to change the ratio of the suction volume of the low-stage compression mechanism and the suction volume of the high-stage compression mechanism in accordance with a change in operating conditions. Yes.

-Driving action-
Also in this air conditioner, the first operating state shown in FIG. 39 and the second operating state shown in FIG. 40 can be switched in accordance with changes in the operating conditions.

  In the first operating state shown in FIG. 39, the three-way valve (107) is set to the first position. When the compressor (100) is started in this state, the low-pressure gas refrigerant evaporated by exchanging heat with air in the evaporator (103) passes from the low-pressure refrigerant pipe (181) to the first suction pipe (182a) and the second suction pipe ( 182b), from the first suction pipe (182a) through the first suction port (154-1) to the first compression mechanism (110), and from the second suction pipe (182b) to the second suction port ( 154-2) and sucked into the second compression mechanism (120). The refrigerant is compressed in the first cylinder chamber (C1) and the second cylinder chamber (C2) to become an intermediate pressure refrigerant.

  The intermediate pressure refrigerant discharged from the cylinder chambers (C1, C2) passes through the first discharge pipe (183a) and the second discharge pipe (183b), and then merges in the intermediate pressure refrigerant pipe (184). The intermediate pressure refrigerant from the liquid separator (104) joins and flows into the branch pipe (185). The intermediate pressure refrigerant flowing through the branch pipe (185) is divided into the third suction pipe (182c) and the fourth suction pipe (182d). The intermediate pressure refrigerant passes from the third suction pipe (182c) through the third suction port (154-3) to the third compression mechanism (130), and from the fourth suction pipe (182d) to the fourth suction port (154). -4) and is sucked into the fourth compression mechanism (140). The refrigerant is compressed in the third cylinder chamber (C3) and the fourth cylinder chamber (C4) to become a high-pressure refrigerant.

  The high-pressure refrigerant discharged from the third discharge port (155-3) passes through the three-way valve (107) and the high-pressure refrigerant introduction pipe (186) from the refrigerant introduction port (156) to the casing (150) of the compressor (100). Introduced in. On the other hand, the high-pressure refrigerant compressed in the fourth cylinder chamber (C4) flows out from the discharge space (162) of the front head (157) into the space in the casing (150). Therefore, the high-pressure refrigerant compressed in the third cylinder chamber (C3) and the high-pressure refrigerant compressed in the fourth cylinder chamber (C4) merge in the casing (150).

  The high-pressure refrigerant in the casing (150) is discharged from the casing (150) through the fourth discharge port (155-4) and passes through the high-pressure refrigerant pipe (fourth discharge pipe) (187) to the gas cooler (102). Inflow. The refrigerant radiates heat to the outdoor air by the gas cooler (102), is then reduced to an intermediate pressure by the first expansion valve (105), and flows into the gas-liquid separator (104). The refrigerant is gas-liquid separated by the gas-liquid separator (104), and the liquid refrigerant flows out of the gas-liquid separator (104). The liquid refrigerant is depressurized to a low pressure by the second expansion valve (106), then evaporated by the evaporator (103), and sucked into the first compression mechanism (110) and the second compression mechanism (120). The gas refrigerant in the gas-liquid separator (104) is introduced into the third compression mechanism (130) and the fourth compression mechanism (140).

  In the second operating state shown in FIG. 40, the three-way valve (107) is set to the second position. When the compressor (100) is started in this state, the low-pressure gas refrigerant evaporated by exchanging heat with air in the evaporator (103) passes from the low-pressure refrigerant pipe (181) to the first suction pipe (182a) and the second suction pipe ( 182b), from the first suction pipe (182a) through the first suction port (154-1) to the first compression mechanism (110), and from the second suction pipe (182b) to the second suction port ( 154-2) and sucked into the second compression mechanism (120). The refrigerant is compressed in the first cylinder chamber (C1) and the second cylinder chamber (C2) to become an intermediate pressure refrigerant.

  The intermediate pressure refrigerant discharged from the cylinder chambers (C1, C2) passes through the first discharge pipe (183a) and the second discharge pipe (183b), and then merges in the intermediate pressure refrigerant pipe (184). The intermediate pressure refrigerant from the separator (104) joins and flows into the branch pipe (185). The intermediate pressure refrigerant flowing through the branch pipe (185) is divided into the third suction pipe (182c) and the fourth suction pipe (182d). The intermediate pressure refrigerant passes from the third suction pipe (182c) through the third suction port (154-3) to the third compression mechanism (130), and from the fourth suction pipe (182d) to the fourth suction port (154). -4) and is sucked into the fourth compression mechanism (140).

  Here, since the three-way valve (107) is switched to the second position, the third discharge pipe (183c) communicates with the second discharge pipe (183b) and has an intermediate pressure. Therefore, in the third compression mechanism (130), the refrigerant is not substantially compressed but is sucked in at an intermediate pressure and flows out with the intermediate pressure.

  On the other hand, in the fourth compression mechanism (140), the refrigerant is compressed in the fourth cylinder chamber (C4) to become a high-pressure refrigerant.

  The high-pressure refrigerant compressed in the fourth cylinder chamber (C4) flows out from the discharge space (162) of the front head (157) into the space in the casing (150). The high-pressure refrigerant in the casing (150) is discharged from the casing (150) through the fourth discharge port (155-4) and passes through the high-pressure refrigerant pipe (fourth discharge pipe) (187) to the gas cooler (102). Inflow. The refrigerant radiates heat to the outdoor air by the gas cooler (102), is then reduced to an intermediate pressure by the first expansion valve (105), and flows into the gas-liquid separator (104). The refrigerant is gas-liquid separated by the gas-liquid separator (104), and the liquid refrigerant flows out of the gas-liquid separator (104). The liquid refrigerant is depressurized to a low pressure by the second expansion valve (106), then evaporated by the evaporator (103), and sucked into the first compression mechanism (110) and the second compression mechanism (120). The gas refrigerant in the gas-liquid separator (104) is introduced into the third compression mechanism (130) and the fourth compression mechanism (140).

-Effects of Reference Technology 4-
According to this embodiment, in the first operating state, the first compression mechanism (110) and the second compression mechanism (120) are used on the lower stage side, and the third compression mechanism (130) and the fourth compression mechanism ( 140) is used on the higher stage side, whereas in the second operating state, the first compression mechanism (110) is passed through the third compression mechanism (130) by passing (through) the refrigerant at an intermediate pressure. ) And the second compression mechanism (120) are used on the lower stage side, and only the fourth compression mechanism (140) is used on the higher stage side.

  As a result, the suction volume on the low stage side is the same in the first operation state and the second operation state, whereas the suction volume on the high stage side is the second operation state rather than the first operation state. Is smaller. That is, the low-stage intake amount is the same in the first operation state and the second operation state, but the substantial high-stage intake amount is smaller in the second operation state than in the first operation state. .

  As described above, in the present embodiment, the refrigerant is not compressed in the third compression mechanism (130) in the second operation state, so that four compression mechanisms (110 to 140) are provided on one shaft. In the mechanically connected compressor (100), the ratio between the suction volume of the low-stage compression mechanism and the suction volume of the high-stage compression mechanism in the first operation state and the second operation state can be adjusted. . Therefore, by switching the volume ratio of the compressor (100) in accordance with the operating conditions, it is possible to perform an operation with a high COP (coefficient of performance). In addition, torque fluctuations associated with refrigerant compression can be adjusted.

<< Reference Technology 5 of Invention >>
Reference technique 5 shown in FIGS. 41 and 42 will be described.

In this reference technique , the structure of the compressor (100) is the same as that of the third embodiment, and the configuration of the refrigerant circuit (180) is different from that of the third embodiment . Therefore, only the refrigerant circuit (180) will be described below. This embodiment is different from the third embodiment in that a three-way valve or a four-way switching valve is not used on the discharge side of the compressor (100) among the components of the refrigerant circuit (180).

  As shown in FIGS. 41 and 42, the low-pressure refrigerant pipe (181) connected to the gas side end of the evaporator (103) is connected to the first compression mechanism (110) through the first suction pipe (182a). 1 is connected to the suction port (154-1). The first suction pipe (182a) branches to a connection pipe (189h), and the connection pipe (189h) is connected to the second port (P2) of the three-way valve (107).

  A first discharge pipe (183a) is connected to the first discharge port (155-1) of the compressor (100), and a second discharge pipe (183b) is connected to the second discharge port (155-2). ing. The first discharge pipe (183a) and the second discharge pipe (183b) are joined and then connected to the intermediate pressure refrigerant pipe (184). The intermediate pressure refrigerant pipe (184) is connected to the refrigerant gas outlet (104a) of the gas-liquid separator (104).

  The intermediate pressure refrigerant pipe (184) branches into the branch pipe (185) on the downstream side of the refrigerant gas outlet (104a) of the gas-liquid separator (104). This branch pipe (185) is connected to the third port (P3) of the three-way valve (107). One end of the second suction pipe (182b) is connected to the first port (P1) of the three-way valve (107), and the other end is connected to the second suction port (154-2) of the second compression mechanism (120). ing. The branch pipe (185) branches into a third suction pipe (182c) and a fourth suction pipe (182d) between a connection point with the intermediate pressure refrigerant pipe (184) and a connection point with the three-way valve (107). The third suction pipe (182c) is connected to the third suction port (154-3) of the third compression mechanism (130), and the fourth suction pipe (182d) is the fourth suction of the fourth compression mechanism (140). Connected to port (154-4).

  The third discharge port (155-3) is connected to the refrigerant introduction port (156) via the third discharge pipe (183c) and the high-pressure refrigerant introduction pipe (186). The third discharge pipe (183c) and the high-pressure refrigerant introduction pipe (186) are configured by a single pipe.

  One end of a high-pressure refrigerant pipe (187) is connected to the fourth discharge port (155-4) of the compressor (100). The other end of the high-pressure refrigerant pipe (187) is connected to the inlet (104b) of the gas-liquid separator (104) via the gas cooler (102) and the first expansion valve (105). The outlet (104c) of the gas-liquid separator (104) is connected to the liquid side end of the evaporator (103) via a liquid pipe (188) provided with a second expansion valve (106) on the way. Yes.

  In the above configuration, the branch pipe (185) constitutes an injection mechanism for injecting the intermediate pressure refrigerant into the compression mechanism (110 to 140).

  In the three-way valve (107), the first position (see FIG. 41) where the first port (P1) and the second port (P2) communicate with each other, and the first port (P1) and the third port (P3) communicate with each other. It can be switched to the second position (see FIG. 42).

  The three-way valve (107) is a switching mechanism (volume ratio changing means) that switches the flow paths of the low-pressure refrigerant, the intermediate-pressure refrigerant, and the high-pressure refrigerant with respect to the compression mechanisms (110 to 140). ) To change the ratio of the suction volume of the low-stage compression mechanism and the suction volume of the high-stage compression mechanism by changing the connection relationship of the four cylinder chambers (C1, C2, C3, C4) It is configured.

  In the switching mechanism (107), the first compression mechanism (110) and the second compression mechanism (120) are on the low stage side, and the third compression mechanism (130) and the fourth compression mechanism (140) are on the high stage side. When the refrigerant is compressed by both the low-stage compression mechanism and the high-stage compression mechanism to generate a pressure difference between the suction side and the discharge side, the first compression mechanism (110) is set to the low-stage side. When the second compression mechanism (120), the third compression mechanism (130), and the fourth compression mechanism (140) are set to the high stage side, the refrigerant is compressed by the low stage side compression mechanism and the pressures on the suction side and the discharge side are compressed. While the difference occurs, the suction side and the discharge side are substantially at the same pressure in one of the second compression mechanism (120), the third compression mechanism (130), and the fourth compression mechanism (140) on the higher stage side. Thus, the refrigerant can be switched between a non-compressed state and a non-compressed state.

  The switching mechanism (volume ratio changing means) (107) is configured to change the ratio of the suction volume of the low-stage compression mechanism and the suction volume of the high-stage compression mechanism in accordance with a change in operating conditions. Yes.

-Driving action-
Also in this air conditioner, it is possible to switch between the first operating state shown in FIG. 41 and the second operating state shown in FIG. 42 as the operating conditions change.

  In the first operating state shown in FIG. 41, the three-way valve (107) is set to the first position. When the compressor (100) is started in this state, the low-pressure gas refrigerant evaporated by exchanging heat with air in the evaporator (103) passes from the low-pressure refrigerant pipe (181) to the first suction pipe (182a) and the second suction pipe ( 182b), from the first suction pipe (182a) through the first suction port (154-1) to the first compression mechanism (110), and from the second suction pipe (182b) to the second suction port ( 154-2) and sucked into the second compression mechanism (120). The refrigerant is compressed in the first cylinder chamber (C1) and the second cylinder chamber (C2) to become an intermediate pressure refrigerant.

  The intermediate pressure refrigerant discharged from the cylinder chambers (C1, C2) passes through the first discharge pipe (183a) and the second discharge pipe (183b), and then merges in the intermediate pressure refrigerant pipe (184). The intermediate pressure refrigerant from the liquid separator (104) joins and flows into the branch pipe (185). The intermediate pressure refrigerant flowing through the branch pipe (185) is divided into the third suction pipe (182c) and the fourth suction pipe (182d). The intermediate pressure refrigerant passes from the third suction pipe (182c) through the third suction port (154-3) to the third compression mechanism (130), and from the fourth suction pipe (182d) to the fourth suction port (154). -4) and is sucked into the fourth compression mechanism (140). The refrigerant is compressed in the third cylinder chamber (C3) and the fourth cylinder chamber (C4) to become a high-pressure refrigerant.

  The high-pressure refrigerant discharged from the third discharge port (155-3) passes through the third discharge pipe (183c) and the high-pressure refrigerant introduction pipe (186) from the refrigerant introduction port (156) to the casing (100) 150). Further, the high-pressure refrigerant compressed in the fourth cylinder chamber (C4) flows out from the discharge space (162) of the front head (157) into the space in the casing (150). Therefore, the high-pressure refrigerant compressed in the third cylinder chamber (C3) and the high-pressure refrigerant compressed in the fourth cylinder chamber (C4) merge in the casing (150).

  The high-pressure refrigerant in the casing (150) is discharged from the casing (150) through the fourth discharge port (155-4) and passes through the high-pressure refrigerant pipe (fourth discharge pipe) (187) to the gas cooler (102). Inflow. The refrigerant radiates heat to the outdoor air by the gas cooler (102), is then reduced to an intermediate pressure by the first expansion valve (105), and flows into the gas-liquid separator (104). The refrigerant is gas-liquid separated by the gas-liquid separator (104), and the liquid refrigerant flows out of the gas-liquid separator (104). The liquid refrigerant is depressurized to a low pressure by the second expansion valve (106), then evaporated by the evaporator (103), and sucked into the first compression mechanism (110) and the second compression mechanism (120). The gas refrigerant in the gas-liquid separator (104) is introduced into the third compression mechanism (130) and the fourth compression mechanism (140).

  In the second operating state shown in FIG. 42, the three-way valve (107) is set to the second position. When the compressor (100) is started in this state, the low-pressure gas refrigerant evaporated by exchanging heat with the air in the evaporator (103) passes through the low-pressure refrigerant pipe (181) and the first suction pipe (182a) to perform the first suction. The air is sucked into the first compression mechanism (110) from the port (154-1). The refrigerant is compressed in the first cylinder chamber (C1) to become an intermediate pressure refrigerant.

  The intermediate pressure refrigerant discharged from the first cylinder chamber (C1) flows through the intermediate pressure refrigerant pipe (184) after passing through the first discharge pipe (183a), and the intermediate pressure refrigerant from the gas-liquid separator (104). Merge and flow into the branch pipe (185). The intermediate pressure refrigerant flowing through the branch pipe (185) is divided into the second suction pipe (182b), the third suction pipe (182c), and the fourth suction pipe (182d). The intermediate pressure refrigerant passes from the second suction pipe (182b) through the second suction port (154-2) to the second compression mechanism (120), and from the third suction pipe (182c) to the third suction port (154). -3) to the third compression mechanism (130), and from the fourth suction pipe (182d) to the fourth compression mechanism (140) through the fourth suction port (154-4).

  Here, the second discharge pipe (183b) joins the first discharge pipe (183a) and is connected to the intermediate pressure refrigerant pipe (184). Therefore, the discharge side of the second compression mechanism (120) is always at an intermediate pressure. For this reason, the intermediate pressure refrigerant sucked into the second compression mechanism (120) is not substantially compressed and flows out of the second compression mechanism (120) while maintaining the intermediate pressure.

  On the other hand, in the third compression mechanism (130) and the fourth compression mechanism (140), the refrigerant is compressed in the third cylinder chamber (C3) and the fourth cylinder chamber (C4) to become a high-pressure refrigerant.

  The high-pressure refrigerant discharged from the third discharge port (155-3) passes through the third discharge pipe (183c) and the high-pressure refrigerant introduction pipe (186) from the refrigerant introduction port (156) to the casing (100) 150). Further, the high-pressure refrigerant compressed in the fourth cylinder chamber (C4) flows out from the discharge space (162) of the front head (157) into the space in the casing (150). Therefore, the high-pressure refrigerant compressed in the third cylinder chamber (C3) and the high-pressure refrigerant compressed in the fourth cylinder chamber (C4) merge in the casing (150).

  The high-pressure refrigerant in the casing (150) is discharged from the casing (150) through the fourth discharge port (155-4) and passes through the high-pressure refrigerant pipe (fourth discharge pipe) (187) to the gas cooler (102). Inflow. The refrigerant radiates heat to the outdoor air by the gas cooler (102), is then reduced to an intermediate pressure by the first expansion valve (105), and flows into the gas-liquid separator (104). The refrigerant is gas-liquid separated by the gas-liquid separator (104), and the liquid refrigerant flows out of the gas-liquid separator (104). The liquid refrigerant is reduced to a low pressure by the second expansion valve (106), then evaporated by the evaporator (103), and sucked into the first compression mechanism (110). The gas refrigerant in the gas-liquid separator (104) is introduced into the second compression mechanism (120), the third compression mechanism (130), and the fourth compression mechanism (140).

-Effects of Reference Technology 5-
According to this reference technique , in the first operating state, the first compression mechanism (110) and the second compression mechanism (120) are used on the lower stage side, and the third compression mechanism (130) and the fourth compression mechanism ( 140) is used on the higher stage side, whereas in the second operating state, the first compression mechanism (110) is passed through the second compression mechanism (120) by allowing the refrigerant to pass through (through) at an intermediate pressure. ) Is used on the lower stage side, and the third compression mechanism (130) and the fourth compression mechanism (140) are used on the higher stage side.

  As a result, the suction volume on the high stage side is the same in the first operation state and the second operation state, whereas the suction volume on the low stage side is the second operation state rather than the first operation state. Is smaller. That is, the high stage intake amount is the same in the first operation state and the second operation state, but the substantial low stage intake amount is smaller in the second operation state than in the first operation state. .

As described above, in the present reference technique , the refrigerant is not compressed in the second compression mechanism (120) in the second operation state, so that four compression mechanisms (110 to 140) are provided on one shaft. In the mechanically connected compressor (100), the ratio between the suction volume of the low-stage compression mechanism and the suction volume of the high-stage compression mechanism in the first operation state and the second operation state can be adjusted. . Therefore, by switching the volume ratio of the compressor (100) in accordance with the operating conditions, it is possible to perform an operation with a high COP (coefficient of performance). In addition, torque fluctuations associated with refrigerant compression can be adjusted.

<< Reference Technology 6 of Invention >>
Reference technique 6 shown in FIGS. 43 and 44 will be described.

In this reference technique , the structure of the compressor (100) is the same as that of the third embodiment, and the configuration of the refrigerant circuit (180) is different from that of the third embodiment . Therefore, only the refrigerant circuit (180) will be described below. The components of the refrigerant circuit (180) are the same as those in the third embodiment .

  As shown in FIGS. 43 and 44, the low-pressure refrigerant pipe (181) connected to the gas side end of the evaporator (103) is connected to the first suction pipe (182a). The first suction pipe (182a) is connected to the first suction port (154-1) of the first compression mechanism (110). The low-pressure refrigerant pipe (181) branches to a connection pipe (189i), and this connection pipe (189i) is connected to the second port (P2) of the first three-way valve (107a). One end of the second suction pipe (182b) is connected to the first port (P1) of the first three-way valve (107a), and the other end of the second suction pipe (182b) is connected to the second compression mechanism (120). 2 It is connected to the suction port (154-2).

  A first discharge pipe (183a) is connected to the first discharge port (155-1) of the compressor (100), and a second discharge pipe (183b) is connected to the second discharge port (155-2). ing. The first discharge pipe (183a) is connected to the first port (P1) of the second three-way valve (107b). One end of the connection pipe (189j) is connected to the second port (P2) of the second three-way valve (107b), and the other end of the connection pipe (189j) is connected to the second discharge pipe (183b). The second discharge pipe (183b) and the connection pipe (189j) are joined and then connected to the intermediate pressure refrigerant pipe (184). The intermediate pressure refrigerant pipe (184) is connected to the refrigerant gas outlet (104a) of the gas-liquid separator (104).

  The third port (P3) of the first three-way valve (107a) and the third port (P3) of the second three-way valve (107b) are connected by a communication pipe (190).

  The intermediate pressure refrigerant pipe (184) branches into the branch pipe (185) on the downstream side of the refrigerant gas outlet (104a) of the gas-liquid separator (104). The branch pipe (185) further branches into a third suction pipe (182c) and a fourth suction pipe (182d). The third suction pipe (182c) is connected to the third suction port (154-3) of the third compression mechanism (130), and the fourth suction pipe (182d) is connected to the fourth suction port ( 154-4).

  The third discharge port (155-3) is connected to the refrigerant introduction port (156) via the third discharge pipe (183c) and the high-pressure refrigerant introduction pipe (186). The third discharge pipe (183c) and the high-pressure refrigerant introduction pipe (186) are configured by a single pipe.

  One end of a high-pressure refrigerant pipe (187) is connected to the fourth discharge port (155-4) of the compressor (100). The other end of the high-pressure refrigerant pipe (187) is connected to the inlet (104b) of the gas-liquid separator (104) via the gas cooler (102) and the first expansion valve (105). The outlet (104c) of the gas-liquid separator (104) is connected to the liquid side end of the evaporator (103) via a liquid pipe (188) provided with a second expansion valve (106) on the way. Yes.

  In the above configuration, the branch pipe (185) constitutes an injection mechanism for injecting the intermediate pressure refrigerant into the compression mechanism (110 to 140).

  Each of the three-way valves (107a, 107b) includes a first position (see FIG. 43) where the first port (P1) and the second port (P2) communicate, a first port (P1), and a third port (P3). Can be switched to the second position (see FIG. 44) where the

  The three-way valves (107a, 107b) are switching mechanisms (volume ratio changing means) that switch the flow paths of the low-pressure refrigerant, the intermediate-pressure refrigerant, and the high-pressure refrigerant with respect to the compression mechanisms (110 to 140). By changing the connection relationship of the four cylinder chambers (C1, C2, C3, C4) in (180) (switching the low-stage compression mechanism in series and parallel), the suction volume of the low-stage compression mechanism And the ratio of the suction volume of the high-stage compression mechanism is changed.

  In the switching mechanism (107a, 107b), the first compression mechanism (110) and the second compression mechanism (120) are on the low stage side, and the third compression mechanism (130) and the fourth compression mechanism (140) are on the high side. When the stage is set to the stage side, the first stage compression mechanism (110) and the second stage compression mechanism (120) on the lower stage side can be switched between a state of being connected in parallel and a state of being connected in series.

  The switching mechanism (volume ratio changing means) is configured to change the ratio of the suction volume of the low-stage compression mechanism and the suction volume of the high-stage compression mechanism in accordance with a change in operating conditions.

-Driving action-
Also in this air conditioner, it is possible to switch between the first operating state shown in FIG. 43 and the second operating state shown in FIG. 44 in accordance with changes in operating conditions.

  In the first operating state shown in FIG. 43, both the first three-way valve (107a) and the second three-way valve (107b) are set to the first position. When the compressor (100) is started in this state, the low-pressure gas refrigerant evaporated by exchanging heat with air in the evaporator (103) passes from the low-pressure refrigerant pipe (181) to the first suction pipe (182a) and the second suction pipe ( 182b), from the first suction pipe (182a) through the first suction port (154-1) to the first compression mechanism (110), and from the second suction pipe (182b) to the second suction port ( 154-2) and sucked into the second compression mechanism (120). The refrigerant is compressed in the first cylinder chamber (C1) and the second cylinder chamber (C2) to become an intermediate pressure refrigerant.

  The intermediate pressure refrigerant discharged from the first cylinder chamber (C1) flows from the first discharge pipe (183a) through the second three-way valve (107b) through the connection pipe (189j), and from the second cylinder chamber (C2). The intermediate pressure refrigerant discharged and flowing through the second discharge pipe (183b) and the intermediate pressure refrigerant pipe (184) join together. The refrigerant flowing through the intermediate pressure refrigerant pipe (184) merges with the intermediate pressure refrigerant from the gas-liquid separator (104) and flows into the branch pipe (185). The intermediate pressure refrigerant flowing through the branch pipe (185) is divided into the third suction pipe (182c) and the fourth suction pipe (182d). The intermediate pressure refrigerant passes from the third suction pipe (182c) through the third suction port (154-3) to the third compression mechanism (130), and from the fourth suction pipe (182d) to the fourth suction port (154). -4) and is sucked into the fourth compression mechanism (140). The refrigerant is compressed in the third cylinder chamber (C3) and the fourth cylinder chamber (C4) to become a high-pressure refrigerant.

  The high-pressure refrigerant discharged from the third discharge port (155-3) passes through the third discharge pipe (183c) and the high-pressure refrigerant introduction pipe (186) from the refrigerant introduction port (156) to the casing (100) 150). Further, the high-pressure refrigerant compressed in the fourth cylinder chamber (C4) flows out from the discharge space (162) of the front head (157) into the space in the casing (150). Therefore, the high-pressure refrigerant compressed in the third cylinder chamber (C3) and the high-pressure refrigerant compressed in the fourth cylinder chamber (C4) merge in the casing (150).

  The high-pressure refrigerant in the casing (150) is discharged from the casing (150) through the fourth discharge port (155-4) and passes through the high-pressure refrigerant pipe (fourth discharge pipe) (187) to the gas cooler (102). Inflow. The refrigerant radiates heat to the outdoor air by the gas cooler (102), is then reduced to an intermediate pressure by the first expansion valve (105), and flows into the gas-liquid separator (104). The refrigerant is gas-liquid separated by the gas-liquid separator (104), and the liquid refrigerant flows out of the gas-liquid separator (104). The liquid refrigerant is depressurized to a low pressure by the second expansion valve (106), then evaporated by the evaporator (103), and sucked into the first compression mechanism (110) and the second compression mechanism (120). The gas refrigerant in the gas-liquid separator (104) is introduced into the third compression mechanism (130) and the fourth compression mechanism (140).

  In the second operating state shown in FIG. 44, both the first three-way valve (107a) and the second three-way valve (107b) are set to the second position. When the compressor (100) is started in this state, the low-pressure gas refrigerant evaporated by exchanging heat with the air in the evaporator (103) passes through the low-pressure refrigerant pipe (181) and the first suction pipe (182a) to perform the first suction. The air is sucked into the first compression mechanism (110) from the port (154-1). The refrigerant is compressed in the first cylinder chamber (C1) and becomes the first intermediate pressure refrigerant.

  The first intermediate pressure refrigerant is discharged from the first cylinder chamber (C1), and the first discharge pipe (183a), the second three-way valve (107b), the communication pipe (190), the first three-way valve (107a), 2 is sucked into the second compression mechanism (120) from the second suction port (154-2) through the suction pipe (182b). The refrigerant is compressed in the second cylinder chamber (C2) and becomes a second intermediate pressure refrigerant (intermediate pressure refrigerant of two-stage compression).

  The second intermediate-pressure refrigerant discharged from the second cylinder chamber (C2) flows through the intermediate-pressure refrigerant pipe (184) after passing through the second discharge pipe (183b), and passes through the intermediate pressure from the gas-liquid separator (104). It merges with the pressure refrigerant and flows into the branch pipe (185). The intermediate pressure refrigerant flowing through the branch pipe (185) is divided into the third suction pipe (182c) and the fourth suction pipe (182d). The intermediate pressure refrigerant passes from the third suction pipe (182c) through the third suction port (154-3) to the third compression mechanism (130), and from the fourth suction pipe (182d) to the fourth suction port (154). -4) and is sucked into the fourth compression mechanism (140). In the third compression mechanism (130) and the fourth compression mechanism (140), the refrigerant is compressed in the third cylinder chamber (C3) and the fourth cylinder chamber (C4) to become a high-pressure refrigerant.

  The high-pressure refrigerant discharged from the third discharge port (155-3) passes through the third discharge pipe (183c) and the high-pressure refrigerant introduction pipe (186) from the refrigerant introduction port (156) to the casing (100) 150). Further, the high-pressure refrigerant compressed in the fourth cylinder chamber (C4) flows out from the discharge space (162) of the front head (157) into the space in the casing (150). Therefore, the high-pressure refrigerant compressed in the third cylinder chamber (C3) and the high-pressure refrigerant compressed in the fourth cylinder chamber (C4) merge in the casing (150).

  The high-pressure refrigerant in the casing (150) is discharged from the casing (150) through the fourth discharge port (155-4) and passes through the high-pressure refrigerant pipe (fourth discharge pipe) (187) to the gas cooler (102). Inflow. The refrigerant radiates heat to the outdoor air by the gas cooler (102), is then reduced to an intermediate pressure by the first expansion valve (105), and flows into the gas-liquid separator (104). The refrigerant is gas-liquid separated by the gas-liquid separator (104), and the liquid refrigerant flows out of the gas-liquid separator (104). The liquid refrigerant is reduced to a low pressure by the second expansion valve (106), then evaporated by the evaporator (103), and sucked into the first compression mechanism (110). The gas refrigerant in the gas-liquid separator (104) is introduced into the third compression mechanism (130) and the fourth compression mechanism (140).

-Effects of Reference Technology 6-
According to this reference technique , the first compression mechanism (110) and the second compression mechanism (120) that are on the lower stage side are used in parallel in the first operation state, but in series in the second operation state. I have to. Therefore, the suction volume on the lower stage side is smaller in the second operating state than in the first operating state. On the other hand, the high stage side uses the third compression mechanism (130) and the fourth compression mechanism (140) in parallel in both the first operation state and the second operation state, and the suction volume does not change.

  As a result, the suction volume on the high stage side is the same in the first operation state and the second operation state, whereas the suction volume on the low stage side is the second operation state than the first operation state. Is smaller. That is, the high stage intake amount is the same in the first operation state and the second operation state, but the substantial low stage intake amount is smaller in the second operation state than in the first operation state. .

As described above, in this reference technique , the two low-stage compression mechanisms (110, 120) are used in parallel in the first operation state and in series in the second operation state, so that one shaft is used. In the compressor (100) in which the four compression mechanisms (110 to 140) are mechanically connected, the suction volume of the low-stage compression mechanism and the high-stage compression mechanism in the first operation state and the second operation state The ratio of the suction volume can be adjusted. Therefore, by switching the volume ratio of the compressor (100) in accordance with the operating conditions, it is possible to perform an operation with a high COP (coefficient of performance). In addition, torque fluctuations associated with refrigerant compression can be adjusted.

<< Reference Technology 7 of Invention >>
Reference technique 7 shown in FIGS. 45 and 46 will be described.

In this reference technique , the structure of the compressor (100) is the same as that of the third embodiment, and the configuration of the refrigerant circuit (180) is different from that of the third embodiment . Therefore, only the refrigerant circuit (180) will be described below. The components of the refrigerant circuit (180) are the same as those in the third embodiment .

  As shown in FIGS. 45 and 46, the low-pressure refrigerant pipe (181) connected to the gas side end of the evaporator (103) branches into a first suction pipe (182a) and a second suction pipe (182b). Yes. The first suction pipe (182a) is connected to the first suction port (154-1) of the first compression mechanism (110), and the second suction pipe (182b) is connected to the second suction port (120) of the second compression mechanism (120). 154-2).

  A first discharge pipe (183a) is connected to the first discharge port (155-1) of the compressor (100), and a second discharge pipe (183b) is connected to the second discharge port (155-2). ing. The first discharge pipe (183a) and the second discharge pipe (183b) merge and are connected to the intermediate pressure refrigerant pipe (184). The intermediate pressure refrigerant pipe (184) is connected to the refrigerant gas outlet (104a) of the gas-liquid separator (104).

  The intermediate pressure refrigerant pipe (184) branches into the branch pipe (185) on the downstream side of the refrigerant gas outlet (104a) of the gas-liquid separator (104). The branch pipe (185) is connected to the third suction port (154-3) of the third compression mechanism (130) via the third suction pipe (182c). The branch pipe (185) is branched into a connection pipe (189k) on the way, and the connection pipe (189k) is connected to the second port (P2) of the first three-way valve (107a). One end of the fourth suction pipe (182d) is connected to the first port (P1) of the first three-way valve (107a), and the other end of the fourth suction pipe (182d) is the fourth port of the fourth compression mechanism (140). It is connected to the suction port (154-4).

  One end of a third discharge pipe (183c) is connected to the third discharge port (155-3), and the other end of the third discharge pipe (183c) is connected to the first port (P1) of the second three-way valve (107b). It is connected. The second port (P2) of the second three-way valve (107b) is connected to the refrigerant introduction port (156) via the high-pressure refrigerant introduction pipe (186).

  The third port (P3) of the first three-way valve (107a) and the third port (P3) of the second three-way valve (107b) are connected by a communication pipe (190).

  One end of a high-pressure refrigerant pipe (187) is connected to the fourth discharge port (155-4) of the compressor (100). The other end of the high-pressure refrigerant pipe (187) is connected to the inlet (104b) of the gas-liquid separator (104) via the gas cooler (102) and the first expansion valve (105). The outlet (104c) of the gas-liquid separator (104) is connected to the liquid side end of the evaporator (103) via a liquid pipe (188) provided with a second expansion valve (106) on the way. Yes.

  In the above configuration, the branch pipe (185) constitutes an injection mechanism for injecting the intermediate pressure refrigerant into the compression mechanism (110 to 140).

  Each of the three-way valves (107a, 107b) includes a first position (see FIG. 45) where the first port (P1) and the second port (P2) communicate with each other, a first port (P1) and a third port (P3). Can be switched to the second position (see FIG. 46) where the

  The three-way valves (107a, 107b) are switching mechanisms (volume ratio changing means) that switch the flow paths of the low-pressure refrigerant, the intermediate-pressure refrigerant, and the high-pressure refrigerant with respect to the compression mechanisms (110 to 140). By changing the connection relationship of the four cylinder chambers (C1, C2, C3, C4) in (180) (switching the high-stage compression mechanism in series and parallel), the suction volume of the low-stage compression mechanism And the ratio of the suction volume of the high-stage compression mechanism is changed.

  In the switching mechanism (107a, 107b), the first compression mechanism (110) and the second compression mechanism (120) are on the low stage side, and the third compression mechanism (130) and the fourth compression mechanism (140) are on the high side. When the stage side is selected, the third stage compression mechanism (130) and the fourth stage compression mechanism (140) on the higher stage side can be switched between the state shown in FIG. 45 connected in parallel and the state shown in FIG. 46 connected in series. Has been.

  The switching mechanism (volume ratio changing means) is configured to change the ratio of the suction volume of the low-stage compression mechanism and the suction volume of the high-stage compression mechanism in accordance with a change in operating conditions.

-Driving action-
Also in this air conditioner, the first operating state shown in FIG. 45 and the second operating state shown in FIG. 46 can be switched in accordance with a change in operating conditions.

  In the first operating state shown in FIG. 45, both the first three-way valve (107a) and the second three-way valve (107b) are set to the first position. When the compressor (100) is started in this state, the low-pressure gas refrigerant evaporated by exchanging heat with air in the evaporator (103) passes from the low-pressure refrigerant pipe (181) to the first suction pipe (182a) and the second suction pipe ( 182b), from the first suction pipe (182a) through the first suction port (154-1) to the first compression mechanism (110), and from the second suction pipe (182b) to the second suction port ( 154-2) and sucked into the second compression mechanism (120). The refrigerant is compressed in the first cylinder chamber (C1) and the second cylinder chamber (C2) to become an intermediate pressure refrigerant.

  Intermediate pressure refrigerant discharged from the first cylinder chamber (C1), passing through the first discharge port (155-1) and flowing through the first discharge pipe (183a), and discharged from the second cylinder chamber (C2) to the second The intermediate pressure refrigerant flowing through the discharge port (155-2) and flowing through the second discharge pipe (183b) joins at the intermediate pressure refrigerant pipe (184).

  The refrigerant flowing through the intermediate pressure refrigerant pipe (184) merges with the intermediate pressure refrigerant from the gas-liquid separator (104) and flows into the branch pipe (185). The intermediate pressure refrigerant flowing through the branch pipe (185) is divided into the third suction pipe (182c) and the fourth suction pipe (182d). The intermediate pressure refrigerant passes from the third suction pipe (182c) through the third suction port (154-3) to the third compression mechanism (130), and from the fourth suction pipe (182d) to the fourth suction port (154). -4) and is sucked into the fourth compression mechanism (140). The refrigerant is compressed in the third cylinder chamber (C3) and the fourth cylinder chamber (C4) to become a high-pressure refrigerant.

  The high-pressure refrigerant discharged from the third discharge port (155-3) passes through the third discharge pipe (183c) and the high-pressure refrigerant introduction pipe (186) from the refrigerant introduction port (156) to the casing (100) 150). Further, the high-pressure refrigerant compressed in the fourth cylinder chamber (C4) flows out from the discharge space (162) of the front head (157) into the space in the casing (150). Therefore, the high-pressure refrigerant compressed in the third cylinder chamber (C3) and the high-pressure refrigerant compressed in the fourth cylinder chamber (C4) merge in the casing (150).

  The high-pressure refrigerant in the casing (150) is discharged from the casing (150) through the fourth discharge port (155-4) and passes through the high-pressure refrigerant pipe (fourth discharge pipe) (187) to the gas cooler (102). Inflow. The refrigerant radiates heat to the outdoor air by the gas cooler (102), is then reduced to an intermediate pressure by the first expansion valve (105), and flows into the gas-liquid separator (104). The refrigerant is gas-liquid separated by the gas-liquid separator (104), and the liquid refrigerant flows out of the gas-liquid separator (104). The liquid refrigerant is depressurized to a low pressure by the second expansion valve (106), then evaporated by the evaporator (103), and sucked into the first compression mechanism (110) and the second compression mechanism (120). The gas refrigerant in the gas-liquid separator (104) is introduced into the third compression mechanism (130) and the fourth compression mechanism (140).

  In the second operating state shown in FIG. 46, both the first three-way valve (107a) and the second three-way valve (107b) are set to the second position. When the compressor (100) is started in this state, the low-pressure gas refrigerant evaporated by exchanging heat with air in the evaporator (103) passes from the low-pressure refrigerant pipe (181) to the first suction pipe (182a) and the second suction pipe ( 182b), from the first suction pipe (182a) through the first suction port (154-1) to the first compression mechanism (110), and from the second suction pipe (182b) to the second suction port ( 154-2) and sucked into the second compression mechanism (120). The refrigerant is compressed in the first cylinder chamber (C1) and the second cylinder chamber (C2) to become a first intermediate pressure refrigerant (intermediate pressure refrigerant of two-stage compression).

  Intermediate pressure refrigerant discharged from the first cylinder chamber (C1), passing through the first discharge port (155-1) and flowing through the first discharge pipe (183a), and discharged from the second cylinder chamber (C2) to the second The intermediate pressure refrigerant flowing through the discharge port (155-2) and flowing through the second discharge pipe (183b) joins at the intermediate pressure refrigerant pipe (184).

  The refrigerant flowing through the intermediate pressure refrigerant pipe (184) merges with the intermediate pressure refrigerant from the gas-liquid separator (104) and flows into the branch pipe (185). The intermediate pressure refrigerant flowing through the branch pipe (185) flows into the third suction pipe (182c). The first intermediate pressure refrigerant is sucked into the third compression mechanism (130) from the third suction pipe (182c) through the third suction port (154-3), and is compressed in the third cylinder chamber (C3). The second intermediate pressure refrigerant is obtained.

  The second intermediate pressure refrigerant discharged from the third cylinder chamber (C3) passes through the third discharge port (155-3), the third discharge pipe (183c), the second three-way valve (107b), and the communication pipe (190). ) And the fourth suction pipe (182d) in order, and is sucked into the fourth compression mechanism (140) from the fourth suction port (154-4). The refrigerant is compressed in the fourth cylinder chamber (C4) to become a high-pressure refrigerant. The high-pressure refrigerant compressed in the fourth cylinder chamber (C4) flows out from the discharge space (162) of the front head (157) into the space in the casing (150).

  The high-pressure refrigerant in the casing (150) is discharged from the casing (150) through the fourth discharge port (155-4) and passes through the high-pressure refrigerant pipe (fourth discharge pipe) (187) to the gas cooler (102). Inflow. The refrigerant radiates heat to the outdoor air by the gas cooler (102), is then reduced to an intermediate pressure by the first expansion valve (105), and flows into the gas-liquid separator (104). The refrigerant is gas-liquid separated by the gas-liquid separator (104), and the liquid refrigerant flows out of the gas-liquid separator (104). The liquid refrigerant is depressurized to a low pressure by the second expansion valve (106), then evaporated by the evaporator (103), and sucked into the first compression mechanism (110) and the second compression mechanism (120). The gas refrigerant in the gas-liquid separator (104) is introduced into the third compression mechanism (130).

-Effects of Reference Technology 7-
According to this reference technique , the third compression mechanism (130) and the fourth compression mechanism (140), which are on the higher stage side, are used in parallel in the first operation state, but in series in the second operation state. I have to. Therefore, the suction volume on the high stage side is smaller in the second operating state than in the first operating state. On the other hand, the lower stage side uses the first compression mechanism (110) and the second compression mechanism (120) in parallel in both the first operation state and the second operation state, and the suction volume does not change.

  As a result, the suction volume on the low stage side is the same in the first operation state and the second operation state, whereas the suction volume on the high stage side is the second operation state rather than the first operation state. Is smaller. That is, the low-stage intake amount is the same in the first operation state and the second operation state, but the substantial high-stage intake amount is smaller in the second operation state than in the first operation state. .

As described above, in the present reference technique , the two high-stage compression mechanisms (130, 140) are used in parallel in the first operation state, and are used in series in the second operation state. In the compressor (100) in which the four compression mechanisms (110 to 140) are mechanically connected, the suction volume of the low-stage compression mechanism and the high-stage compression mechanism in the first operation state and the second operation state The ratio of the suction volume can be adjusted. Therefore, by switching the volume ratio of the compressor (100) in accordance with the operating conditions, it is possible to perform an operation with a high COP (coefficient of performance). In addition, torque fluctuations associated with refrigerant compression can be adjusted.

<< Other Embodiments >>
About the said embodiment, it is good also as the following structures.

In the above embodiment, the volumes of the four cylinder chambers are all different. However, in the base technology of the invention, the first and second embodiments, and the reference techniques 1 to 3 , the four cylinder chambers are divided into at least two types of suction volumes. It may be set. In that case, the volume of the outer cylinder chamber (C1) of the first compression mechanism (20) and the outer cylinder chamber (C3) of the second compression mechanism (30) are the same, and the inner cylinder chamber of the first compression mechanism (20). The volume of the inner cylinder chamber (C4) of (C2) and the second compression mechanism (30) is the same. Even in this case, the first operation state in which the two cylinder chambers of the compression mechanism (20, 30) are used in parallel and the second operation state in which the compression chamber (20, 30) is used in series can be switched, or each cylinder chamber (C1, C2, C3, By changing the combination of the high pressure side and low pressure side of C4), the volume ratio of the compressor (1) can be changed according to the operating conditions.

Further, in Embodiments 3 to 5 and Reference Technologies 4 to 7 , the cylinder chambers (C1) to (C4) may have the same volume except for Embodiment 5 .

Furthermore, if the present invention is a refrigeration apparatus using a compressor having four cylinder chambers, the configuration of the compressor may be arbitrarily changed. For example, in Embodiments 3 to 5 and Reference Technologies 4 to 7 , a rolling piston compressor in which a blade is separated from a piston may be used.

Moreover, although the three-way valve (7) is used in the base technology, Embodiment 1 and Reference Technologies 1 and 2 , and the four-way switching valve (8) is used in Embodiment 3, a plurality of on-off valves (solenoid valves) are used. They may be used in combination.

  As shown in FIGS. 47 and 48, the internal pressure of the casing (10) may be any of a low pressure, a high pressure, and an intermediate pressure. The setting of the internal pressure can be arbitrarily changed by appropriately configuring the refrigerant circuit.

  In each of the above embodiments, the refrigerant filled in the refrigerant circuit (60, 180) may be a refrigerant other than carbon dioxide (for example, a fluorocarbon refrigerant).

  In each of the above embodiments, the injection pipe (68, 185) is used as the cooling means for cooling the refrigerant in the intermediate stage of the compressor (1, 100). However, the heat exchanger (intercooler) is used as the cooling means. May be used.

  Furthermore, although the said embodiment demonstrated the air conditioning apparatus which performs air_conditionaing | cooling operation, this invention is not limited to a cooling only machine.

(Example of combination of suction port and discharge port in Embodiments 1 to 6)
In the base technology , the first and second embodiments, and the reference technologies 1 to 3 , the first suction port (14-1), the first discharge port (15-1), the second suction port (14-2), The second discharge port (15-2) may be configured as shown in FIGS. 49 to 62, for example.

  49, the first suction port (14-1) includes a first a suction port (14-1a) for sucking refrigerant into the first outer cylinder chamber (C1), and a first inner side. It is constituted by a 1b suction port (14-1b) for sucking refrigerant into the cylinder chamber (C2). The first discharge port (15-1) is composed of one discharge port for discharging refrigerant from both the first outer cylinder chamber (C1) and the first inner cylinder chamber (C2). The second suction port (14-2) is constituted by a single suction port for sucking refrigerant into both the second outer cylinder chamber (C3) and the second inner cylinder chamber (C4). The second discharge port (15-2) is constituted by one discharge port for discharging refrigerant from both the second outer cylinder chamber (C3) and the second inner cylinder chamber (C4).

  In the second modified example of FIG. 50, the first suction port (14-1) is a single port for sucking refrigerant into both the first outer cylinder chamber (C1) and the first inner cylinder chamber (C2). It is composed of a suction port. The first discharge port (15-1) discharges refrigerant from the first a discharge port (15-1a) for discharging refrigerant from the first outer cylinder chamber (C1) and from the first inner cylinder chamber (C2). 1b discharge port (15-1b) for this purpose. The second suction port (14-2) is constituted by a single suction port for sucking refrigerant into both the second outer cylinder chamber (C3) and the second inner cylinder chamber (C4). The second discharge port (15-2) is constituted by one discharge port for discharging refrigerant from both the second outer cylinder chamber (C3) and the second inner cylinder chamber (C4).

  In the third modified example of FIG. 51, the first suction port (14-1) is a single port for sucking refrigerant into both the first outer cylinder chamber (C1) and the first inner cylinder chamber (C2). It is composed of a suction port. The first discharge port (15-1) is composed of one discharge port for discharging refrigerant from both the first outer cylinder chamber (C1) and the first inner cylinder chamber (C2). The second suction port (14-2) sucks the refrigerant into the second outer cylinder chamber (C3), the second a suction port (14-2a) for sucking the refrigerant into the second outer cylinder chamber (C3), and the second inner cylinder chamber (C4). It is comprised by the 2b suction port (14-2b) for this. The second discharge port (15-2) is constituted by one discharge port for discharging refrigerant from both the second outer cylinder chamber (C3) and the second inner cylinder chamber (C4).

  In the fourth modified example of FIG. 52, the first suction port (14-1) is provided with a single port for sucking refrigerant into both the first outer cylinder chamber (C1) and the first inner cylinder chamber (C2). It is composed of a suction port. The first discharge port (15-1) is composed of one discharge port for discharging refrigerant from both the first outer cylinder chamber (C1) and the first inner cylinder chamber (C2). The second suction port (14-2) is constituted by a single suction port for sucking refrigerant into both the second outer cylinder chamber (C3) and the second inner cylinder chamber (C4). The second discharge port (15-2) discharges refrigerant from the second a discharge port (15-2a) for discharging refrigerant from the second outer cylinder chamber (C3) and from the second inner cylinder chamber (C4). The second b discharge port (15-2b) for this purpose.

  In the fifth modification of FIG. 53, the first suction port (14-1) is provided with a single port for sucking refrigerant into both the first outer cylinder chamber (C1) and the first inner cylinder chamber (C2). It is composed of a suction port. The first discharge port (15-1) discharges refrigerant from the first a discharge port (15-1a) for discharging refrigerant from the first outer cylinder chamber (C1) and from the first inner cylinder chamber (C2). 1b discharge port (15-1b) for this purpose. The second suction port (14-2) sucks the refrigerant into the second outer cylinder chamber (C3), the second a suction port (14-2a) for sucking the refrigerant into the second outer cylinder chamber (C3), and the second inner cylinder chamber (C4). It is comprised by the 2b suction port (14-2b) for this. The second discharge port (15-2) discharges refrigerant from the second a discharge port (15-2a) for discharging refrigerant from the second outer cylinder chamber (C3) and from the second inner cylinder chamber (C4). The second b discharge port (15-2b) for this purpose.

  54, the first suction port (14-1) includes a first a suction port (14-1a) for sucking refrigerant into the first outer cylinder chamber (C1), and a first inner side. It is constituted by a 1b suction port (14-1b) for sucking refrigerant into the cylinder chamber (C2). The first discharge port (15-1) discharges refrigerant from the first a discharge port (15-1a) for discharging refrigerant from the first outer cylinder chamber (C1) and from the first inner cylinder chamber (C2). 1b discharge port (15-1b) for this purpose. The second suction port (14-2) is constituted by a single suction port for sucking refrigerant into both the second outer cylinder chamber (C3) and the second inner cylinder chamber (C4). The second discharge port (15-2) discharges refrigerant from the second a discharge port (15-2a) for discharging refrigerant from the second outer cylinder chamber (C3) and from the second inner cylinder chamber (C4). The second b discharge port (15-2b) for this purpose.

  In the seventh modified example of FIG. 55, the first suction port (14-1) is a single port for sucking refrigerant into both the first outer cylinder chamber (C1) and the first inner cylinder chamber (C2). It is composed of a suction port. The first discharge port (15-1) discharges refrigerant from the first a discharge port (15-1a) for discharging refrigerant from the first outer cylinder chamber (C1) and from the first inner cylinder chamber (C2). 1b discharge port (15-1b) for this purpose. The second suction port (14-2) is constituted by a single suction port for sucking refrigerant into both the second outer cylinder chamber (C3) and the second inner cylinder chamber (C4). The second discharge port (15-2) discharges refrigerant from the second a discharge port (15-2a) for discharging refrigerant from the second outer cylinder chamber (C3) and from the second inner cylinder chamber (C4). The second b discharge port (15-2b) for this purpose.

  56, the first suction port (14-1) includes a first a suction port (14-1a) for sucking refrigerant into the first outer cylinder chamber (C1), and a first inner side. It is constituted by a 1b suction port (14-1b) for sucking refrigerant into the cylinder chamber (C2). The first discharge port (15-1) is composed of one discharge port for discharging refrigerant from both the first outer cylinder chamber (C1) and the first inner cylinder chamber (C2). The second suction port (14-2) sucks the refrigerant into the second outer cylinder chamber (C3), the second a suction port (14-2a) for sucking the refrigerant into the second outer cylinder chamber (C3), and the second inner cylinder chamber (C4). It is comprised by the 2b suction port (14-2b) for this. The second discharge port (15-2) discharges refrigerant from the second a discharge port (15-2a) for discharging refrigerant from the second outer cylinder chamber (C3) and from the second inner cylinder chamber (C4). The second b discharge port (15-2b) for this purpose.

  57, the first suction port (14-1) includes a first a suction port (14-1a) for sucking refrigerant into the first outer cylinder chamber (C1), and a first inner side. It is constituted by a 1b suction port (14-1b) for sucking refrigerant into the cylinder chamber (C2). The first discharge port (15-1) discharges refrigerant from the first a discharge port (15-1a) for discharging refrigerant from the first outer cylinder chamber (C1) and from the first inner cylinder chamber (C2). 1b discharge port (15-1b) for this purpose. The second suction port (14-2) sucks the refrigerant into the second outer cylinder chamber (C3), the second a suction port (14-2a) for sucking the refrigerant into the second outer cylinder chamber (C3), and the second inner cylinder chamber (C4). It is comprised by the 2b suction port (14-2b) for this. The second discharge port (15-2) is constituted by one discharge port for discharging refrigerant from both the second outer cylinder chamber (C3) and the second inner cylinder chamber (C4).

  In the tenth modified example of FIG. 58, the first suction port (14-1) is a single port for sucking refrigerant into both the first outer cylinder chamber (C1) and the first inner cylinder chamber (C2). It is composed of a suction port. The first discharge port (15-1) is composed of one discharge port for discharging refrigerant from both the first outer cylinder chamber (C1) and the first inner cylinder chamber (C2). The second suction port (14-2) sucks the refrigerant into the second outer cylinder chamber (C3), the second a suction port (14-2a) for sucking the refrigerant into the second outer cylinder chamber (C3), and the second inner cylinder chamber (C4). It is comprised by the 2b suction port (14-2b) for this. The second discharge port (15-2) discharges refrigerant from the second a discharge port (15-2a) for discharging refrigerant from the second outer cylinder chamber (C3) and from the second inner cylinder chamber (C4). The second b discharge port (15-2b) for this purpose.

  In the eleventh modification of FIG. 59, the first suction port (14-1) includes a first a suction port (14-1a) for sucking refrigerant into the first outer cylinder chamber (C1), and a first inner side. It is constituted by a 1b suction port (14-1b) for sucking refrigerant into the cylinder chamber (C2). The first discharge port (15-1) is composed of one discharge port for discharging refrigerant from both the first outer cylinder chamber (C1) and the first inner cylinder chamber (C2). The second suction port (14-2) is constituted by a single suction port for sucking refrigerant into both the second outer cylinder chamber (C3) and the second inner cylinder chamber (C4). The second discharge port (15-2) discharges refrigerant from the second a discharge port (15-2a) for discharging refrigerant from the second outer cylinder chamber (C3) and from the second inner cylinder chamber (C4). The second b discharge port (15-2b) for this purpose.

  In the twelfth modified example of FIG. 60, the first suction port (14-1) is a single port for sucking refrigerant into both the first outer cylinder chamber (C1) and the first inner cylinder chamber (C2). It is composed of a suction port. The first discharge port (15-1) discharges refrigerant from the first a discharge port (15-1a) for discharging refrigerant from the first outer cylinder chamber (C1) and from the first inner cylinder chamber (C2). 1b discharge port (15-1b) for this purpose. The second suction port (14-2) sucks the refrigerant into the second outer cylinder chamber (C3), the second a suction port (14-2a) for sucking the refrigerant into the second outer cylinder chamber (C3), and the second inner cylinder chamber (C4). It is comprised by the 2b suction port (14-2b) for this. The second discharge port (15-2) is constituted by one discharge port for discharging refrigerant from both the second outer cylinder chamber (C3) and the second inner cylinder chamber (C4).

  In the thirteenth modification of FIG. 61, the first suction port (14-1) includes a first a suction port (14-1a) for sucking refrigerant into the first outer cylinder chamber (C1), and a first inner side. It is constituted by a 1b suction port (14-1b) for sucking refrigerant into the cylinder chamber (C2). The first discharge port (15-1) discharges refrigerant from the first a discharge port (15-1a) for discharging refrigerant from the first outer cylinder chamber (C1) and from the first inner cylinder chamber (C2). 1b discharge port (15-1b) for this purpose. The second suction port (14-2) is constituted by a single suction port for sucking refrigerant into both the second outer cylinder chamber (C3) and the second inner cylinder chamber (C4). The second discharge port (15-2) is constituted by one discharge port for discharging refrigerant from both the second outer cylinder chamber (C3) and the second inner cylinder chamber (C4).

  62, the first suction port (14-1) includes a first a suction port (14-1a) for sucking refrigerant into the first outer cylinder chamber (C1), and a first inner side. It is constituted by a 1b suction port (14-1b) for sucking refrigerant into the cylinder chamber (C2). The first discharge port (15-1) is composed of one discharge port for discharging refrigerant from both the first outer cylinder chamber (C1) and the first inner cylinder chamber (C2). The second suction port (14-2) sucks the refrigerant into the second outer cylinder chamber (C3), the second a suction port (14-2a) for sucking the refrigerant into the second outer cylinder chamber (C3), and the second inner cylinder chamber (C4). It is comprised by the 2b suction port (14-2b) for this. The second discharge port (15-2) is constituted by one discharge port for discharging refrigerant from both the second outer cylinder chamber (C3) and the second inner cylinder chamber (C4).

  As described above, the suction port and the discharge port can be used in various combinations, and the volume ratio can be adjusted by appropriately selecting them.

  In addition, the above embodiment is an essentially preferable illustration, Comprising: It does not intend restrict | limiting the range of this invention, its application thing, or its use.

  As described above, the present invention is useful for a refrigeration apparatus for a two-stage compression refrigeration cycle.

FIG. 1 is a longitudinal cross-sectional view of a compressor used in an air conditioner according to the prerequisite technology . FIG. 2 is a cross-sectional view of the compression mechanism of the base technology . FIG. 3 is an operation state diagram of the compression mechanism of the base technology . FIG. 4 is a refrigerant circuit diagram illustrating a first operation state of the air-conditioning apparatus according to the base technology . FIG. 5 is a refrigerant circuit diagram illustrating a second operation state of the air-conditioning apparatus according to the prerequisite technology . FIG. 6 is a cross-sectional view showing a first operation state switching pattern according to a modification of the base technology . FIG. 7 is a cross-sectional view showing a second operation state switching pattern according to a modification of the base technology . FIG. 8 is a cross-sectional view showing a third operation state switching pattern according to a modification of the base technology . FIG. 9 is a cross-sectional view showing a fourth operation state switching pattern according to a modification of the base technology . FIG. 10 is a cross-sectional view showing a fifth operation state switching pattern according to a modification of the base technology . FIG. 11 is a refrigerant circuit diagram illustrating a first operation state of the air-conditioning apparatus according to Embodiment 1 . FIG. 12 is a refrigerant circuit diagram illustrating a second operation state of the air-conditioning apparatus according to Embodiment 1 . FIG. 13 is a cross-sectional view showing a first operating state switching pattern according to a modification of the first embodiment . FIG. 14 is a cross-sectional view showing a second operation state switching pattern according to a modification of the first embodiment . FIG. 15 is a cross-sectional view illustrating a third operation state switching pattern according to a modification of the first embodiment . FIG. 16 is a cross-sectional view showing a fourth operating state switching pattern according to a modification of the first embodiment . FIG. 17 is a cross-sectional view showing a fifth operating state switching pattern according to a modification of the first embodiment . FIG. 18 is a cross-sectional view illustrating a sixth operating state switching pattern according to a modification of the first embodiment . FIG. 19 is a cross-sectional view showing a seventh operation state switching pattern according to a modification of the first embodiment . FIG. 20 is a cross-sectional view illustrating an eighth operating state switching pattern according to a modification of the first embodiment . FIG. 21 is a cross-sectional view showing a ninth operation state switching pattern according to a modification of the first embodiment . FIG. 22 is a refrigerant circuit diagram illustrating a first operation state of the air-conditioning apparatus according to Embodiment 2 . FIG. 23 is a refrigerant circuit diagram illustrating a second operation state of the air-conditioning apparatus according to Embodiment 2 . FIG. 24 is a refrigerant circuit diagram illustrating a first operation state of the air-conditioning apparatus according to Reference Technology 1 . FIG. 25 is a refrigerant circuit diagram illustrating a second operation state of the air-conditioning apparatus according to Reference Technology 1 . FIG. 26 is a refrigerant circuit diagram illustrating a first operation state of the air-conditioning apparatus according to Reference Technology 2 . FIG. 27 is a refrigerant circuit diagram illustrating a second operation state of the air-conditioning apparatus according to Reference Technology 2 . FIG. 28 is a refrigerant circuit diagram illustrating a first operation state of the air-conditioning apparatus according to Reference Technology 3 . FIG. 29 is a refrigerant circuit diagram illustrating a second operation state of the air-conditioning apparatus according to Reference Technology 3 . FIG. 30 is a longitudinal sectional view of a compressor used in the refrigeration apparatus (air conditioning apparatus) according to the third embodiment . FIG. 31 is a cross-sectional view of the compression mechanism of the third embodiment . FIG. 32 is an operation state diagram of the compression mechanism of the third embodiment . FIG. 33 is a refrigerant circuit diagram illustrating a first operation state of the air-conditioning apparatus according to Embodiment 3 . FIG. 34 is a refrigerant circuit diagram illustrating a second operation state of the air-conditioning apparatus according to Embodiment 3 . FIG. 35 is a refrigerant circuit diagram illustrating a first operation state of the air-conditioning apparatus according to Embodiment 4 . FIG. 36 is a refrigerant circuit diagram illustrating a second operation state of the air-conditioning apparatus according to Embodiment 4 . FIG. 37 is a refrigerant circuit diagram illustrating a first operation state of the air-conditioning apparatus according to Embodiment 5 . FIG. 38 is a refrigerant circuit diagram illustrating a second operation state of the air-conditioning apparatus according to Embodiment 5 . FIG. 39 is a refrigerant circuit diagram illustrating a first operation state of the air-conditioning apparatus according to Reference Technology 4 . FIG. 40 is a refrigerant circuit diagram illustrating a second operation state of the air-conditioning apparatus according to Reference Technology 4 . FIG. 41 is a refrigerant circuit diagram illustrating a first operation state of the air-conditioning apparatus according to Reference Technology 5 . FIG. 42 is a refrigerant circuit diagram illustrating a second operation state of the air-conditioning apparatus according to Reference Technology 5 . FIG. 43 is a refrigerant circuit diagram illustrating a first operation state of the air-conditioning apparatus according to Reference Technology 6 . FIG. 44 is a refrigerant circuit diagram illustrating a second operation state of the air-conditioning apparatus according to Reference Technology 6 . FIG. 45 is a refrigerant circuit diagram illustrating a first operation state of the air-conditioning apparatus according to Reference Technology 7 . FIG. 46 is a refrigerant circuit diagram illustrating a second operation state of the air-conditioning apparatus according to Reference Technology 7 . FIG. 47 is a cross-sectional view showing a modification when the internal pressure of the casing is increased. FIG. 48 is a cross-sectional view showing a modification when the internal pressure of the casing is set to an intermediate pressure. FIG. 49 is a cross-sectional view showing a first modification of the combination of the suction port and the discharge port. FIG. 50 is a cross-sectional view showing a second modification of the combination of the suction port and the discharge port. FIG. 51 is a cross-sectional view showing a third modification of the combination of the suction port and the discharge port. FIG. 52 is a cross-sectional view showing a fourth modification of the combination of the suction port and the discharge port. FIG. 53 is a cross-sectional view showing a fifth modification of the combination of the suction port and the discharge port. FIG. 54 is a cross-sectional view showing a sixth modification of the combination of the suction port and the discharge port. FIG. 55 is a cross-sectional view showing a seventh modification of the combination of the suction port and the discharge port. FIG. 56 is a cross-sectional view showing an eighth modification of the combination of the suction port and the discharge port. FIG. 57 is a sectional view showing a ninth modification of the combination of the suction port and the discharge port. FIG. 58 is a cross-sectional view showing a tenth modification of the combination of the suction port and the discharge port. FIG. 59 is a cross-sectional view showing an eleventh modification of the combination of the suction port and the discharge port. FIG. 60 is a sectional view showing a twelfth modification of the combination of the suction port and the discharge port. FIG. 61 is a cross-sectional view showing a thirteenth modification of the combination of the suction port and the discharge port. FIG. 62 is a cross-sectional view showing a fourteenth modification of the combination of the suction port and the discharge port.

1 Compressor
7 Three-way valve (volume ratio changing means; switching mechanism)
7a First three-way valve (volume ratio changing means; switching mechanism)
7b Second three-way valve (volume ratio changing means; switching mechanism)
8a First four-way selector valve (volume ratio changing means; switching mechanism)
8b Second four-way selector valve (volume ratio changing means; switching mechanism)
20 First compression mechanism
21 1st cylinder
22 First annular piston
30 Second compression mechanism
31 2nd cylinder
32 Second annular piston
53 Drive shaft
100 compressor
110 First compression mechanism
120 Second compression mechanism
130 Third compression mechanism
140 Fourth compression mechanism
111 cylinders
112 cylinders
113 cylinders
114 cylinders
112 Eccentric piston
122 Eccentric piston
132 Eccentric piston
142 Eccentric piston
107 Three-way valve (volume ratio changing means; switching mechanism)
107a First three-way valve (volume ratio changing means; switching mechanism)
107b Second three-way valve (volume ratio changing means; switching mechanism)
108a First four-way selector valve (volume ratio changing means; switching mechanism)
108b Second four-way selector valve (volume ratio changing means; switching mechanism)
C1 1st outer cylinder chamber
C2 1st inner cylinder chamber
C3 Second outer cylinder chamber
C4 Second inner cylinder chamber

Claims (12)

Refrigerant to which a compressor (1) (100) in which a plurality of compression mechanisms (20, 30) (110, 120, 130, 140) are mechanically coupled by a single drive shaft (53) (173) is connected A refrigeration apparatus comprising a circuit (60) (180) and performing a two-stage compression refrigeration cycle,
The compression mechanism (20, 30) (110, 120, 130, 140) includes four cylinder chambers (C1, C2, C3, C4),
Comprising volume ratio changing means (7, 8) (107, 108) for changing the ratio of the suction volume of the low-stage compression mechanism and the suction volume of the high-stage compression mechanism ;
The volume ratio changing means (7, 8) (107, 108) can change the connection between the four cylinder chambers (C1, C2, C3, C4), so that the low-stage compression mechanism and the high-stage compression mechanism Configured to change the ratio of the suction volume,
The plurality of compression mechanisms (20, 30) are a first compression mechanism (20) and a second compression mechanism (30) each having two cylinder chambers (C1, C2) (C3, C4),
Each compression mechanism (20, 30) includes a cylinder (21, 31) having an annular cylinder space, and an annular eccentric piston (22, 32) that performs an eccentric rotational movement in the cylinder space. An inner cylinder chamber (C2, C4) is formed on the inner peripheral side of the annular eccentric piston (22, 32) in FIG. 2, and an outer cylinder chamber (C1, C3) is formed on the outer peripheral side.
The volume ratio changing means (7) includes both cylinder chambers (C3, C2) of the second compression mechanism (30) using both cylinder chambers (C1, C2) of the first compression mechanism (20) as a low-stage compression mechanism. C4) is used for the high-stage compression mechanism, and both cylinder chambers (C1, C2) of the first compression mechanism (20) and one cylinder chamber (C4) of the second compression mechanism (30) are compressed on the low-stage side. A refrigeration apparatus comprising a switching mechanism capable of switching between a state in which the other cylinder chamber (C3) of the second compression mechanism (30) is used as a high- stage compression mechanism . Refrigerant to which a compressor (1) (100) in which a plurality of compression mechanisms (20, 30) (110, 120, 130, 140) are mechanically coupled by a single drive shaft (53) (173) is connected A refrigeration apparatus comprising a circuit (60) (180) and performing a two-stage compression refrigeration cycle,
The compression mechanism (20, 30) (110, 120, 130, 140) includes four cylinder chambers (C1, C2, C3, C4),
Comprising volume ratio changing means (7, 8) (107, 108) for changing the ratio of the suction volume of the low-stage compression mechanism and the suction volume of the high-stage compression mechanism;
The volume ratio changing means (7, 8) (107, 108) can change the connection between the four cylinder chambers (C1, C2, C3, C4), so that the low-stage compression mechanism and the high-stage compression mechanism Configured to change the ratio of the suction volume ,
The plurality of compression mechanisms (20, 30) are a first compression mechanism (20) and a second compression mechanism (30) each having two cylinder chambers (C1, C2) (C3, C4),
Each compression mechanism (20, 30) includes a cylinder (21, 31) having an annular cylinder space, and an annular eccentric piston (22, 32) that performs an eccentric rotational movement in the cylinder space. An inner cylinder chamber (C2, C4) is formed on the inner peripheral side of the annular eccentric piston (22, 32) in FIG. 2, and an outer cylinder chamber (C1, C3) is formed on the outer peripheral side.
The volume ratio changing means (8) includes both cylinder chambers (C3, C2) of the second compression mechanism (30) using both cylinder chambers (C1, C2) of the first compression mechanism (20) as a low-stage compression mechanism. C4) is used for the high-stage compression mechanism, and one cylinder chamber (C1) of the first compression mechanism (20) and one cylinder chamber (C3) of the second compression mechanism (30) are connected to the low-stage compression mechanism. Switching mechanism capable of switching between the state in which the other cylinder chamber (C2) of the first compression mechanism (20) and the other cylinder chamber (C4) of the second compression mechanism (30) are used for the high-stage compression mechanism. refrigeration system, characterized in that it is composed of. In claim 1 or 2,
A refrigeration apparatus characterized in that four cylinder chambers (C1, C2, C3, C4) are set to at least two types of suction volumes . In claim 1 or 2 ,
A refrigeration system characterized in that the intake volumes of the four cylinder chambers (C1, C2, C3, C4) are all different . In any one of Claims 1-4 ,
The volume ratio changing means (7, 8) is constituted by a switching valve that switches a flow path of the low-pressure refrigerant, the intermediate-pressure refrigerant, and the high-pressure refrigerant with respect to the compression mechanisms (20, 30). Refrigeration equipment. In any one of claims 1 to 5 ,
The volume ratio changing means (7, 8) is configured to change the ratio of the suction volume of the low-stage compression mechanism and the suction volume of the high-stage compression mechanism in accordance with a change in operating conditions. Refrigeration equipment. Refrigerant to which a compressor (1) (100) in which a plurality of compression mechanisms (20, 30) (110, 120, 130, 140) are mechanically coupled by a single drive shaft (53) (173) is connected A refrigeration apparatus comprising a circuit (60) (180) and performing a two-stage compression refrigeration cycle,
The compression mechanism (20, 30) (110, 120, 130, 140) includes four cylinder chambers (C1, C2, C3, C4),
Comprising volume ratio changing means (7, 8) (107, 108) for changing the ratio of the suction volume of the low-stage compression mechanism and the suction volume of the high-stage compression mechanism;
The volume ratio changing means (7, 8) (107, 108) can change the connection between the four cylinder chambers (C1, C2, C3, C4), so that the low-stage compression mechanism and the high-stage compression mechanism Configured to change the ratio of the suction volume,
The plurality of compression mechanisms (110, 120, 130, 140) include a first compression mechanism (110), a second compression mechanism (120), a third compression mechanism (130), and a fourth compression mechanism each having one cylinder chamber. Compression mechanism (140),
Each compression mechanism (110, 120, 130, 140) includes a cylinder (111, 121, 131, 141) having a cylindrical cylinder space, and an eccentric piston (112, 122) that performs eccentric rotational movement in the cylinder space. , 132, 142),
The volume ratio changing means (107) uses the first compression mechanism (110) and the second compression mechanism (120) as the low-stage compression mechanism, and the third compression mechanism (130) and the fourth compression mechanism (140). The state used for the high-stage compression mechanism, and the fourth compression mechanism (140) using the first compression mechanism (110), the second compression mechanism (120), and the third compression mechanism (130) as the low-stage compression mechanism. A refrigeration apparatus comprising a switching mechanism that can be switched to a state used for a high-stage compression mechanism . Refrigerant to which a compressor (1) (100) in which a plurality of compression mechanisms (20, 30) (110, 120, 130, 140) are mechanically coupled by a single drive shaft (53) (173) is connected A refrigeration apparatus comprising a circuit (60) (180) and performing a two-stage compression refrigeration cycle,
The compression mechanism (20, 30) (110, 120, 130, 140) includes four cylinder chambers (C1, C2, C3, C4),
Comprising volume ratio changing means (7, 8) (107, 108) for changing the ratio of the suction volume of the low-stage compression mechanism and the suction volume of the high-stage compression mechanism;
The volume ratio changing means (7, 8) (107, 108) can change the connection between the four cylinder chambers (C1, C2, C3, C4), so that the low-stage compression mechanism and the high-stage compression mechanism Configured to change the ratio of the suction volume,
The plurality of compression mechanisms (110, 120, 130, 140) include a first compression mechanism (110), a second compression mechanism (120), a third compression mechanism (130), and a fourth compression mechanism each having one cylinder chamber. Compression mechanism (140),
Each compression mechanism (110, 120, 130, 140) includes a cylinder (111, 121, 131, 141) having a cylindrical cylinder space, and an eccentric piston (112, 122) that performs eccentric rotational movement in the cylinder space. , 132, 142),
The volume ratio changing means (107) uses the first compression mechanism (110) and the third compression mechanism (130) as a low-stage compression mechanism, and the second compression mechanism (120) and the fourth compression mechanism (140). The second compression mechanism (120), the third compression mechanism (130), and the fourth compression mechanism (140) are used by using the first compression mechanism (110) as the low-stage compression mechanism. A refrigeration apparatus comprising a switching mechanism that can be switched to a state used for a high- stage compression mechanism . Refrigerant to which a compressor (1) (100) in which a plurality of compression mechanisms (20, 30) (110, 120, 130, 140) are mechanically coupled by a single drive shaft (53) (173) is connected A refrigeration apparatus comprising a circuit (60) (180) and performing a two-stage compression refrigeration cycle,
The compression mechanism (20, 30) (110, 120, 130, 140) includes four cylinder chambers (C1, C2, C3, C4),
Comprising volume ratio changing means (7, 8) (107, 108) for changing the ratio of the suction volume of the low-stage compression mechanism and the suction volume of the high-stage compression mechanism;
The volume ratio changing means (7, 8) (107, 108) can change the connection between the four cylinder chambers (C1, C2, C3, C4), so that the low-stage compression mechanism and the high-stage compression mechanism Configured to change the ratio of the suction volume,
The plurality of compression mechanisms (110, 120, 130, 140) include a first compression mechanism (110), a second compression mechanism (120), a third compression mechanism (130), and a fourth compression mechanism each having one cylinder chamber. Compression mechanism (140),
Each compression mechanism (110, 120, 130, 140) includes a cylinder (111, 121, 131, 141) having a cylindrical cylinder space, and an eccentric piston (112, 122) that performs eccentric rotational movement in the cylinder space. , 132, 142),
The cylinder volume of at least one compression mechanism is different from the cylinder volume of the other compression mechanism;
The volume ratio changing means (108) uses the first compression mechanism (110) and the second compression mechanism (120) as the low-stage compression mechanism, and the third compression mechanism (130) and the fourth compression mechanism (140). Using the first compression mechanism (110) and the third compression mechanism (130) as the low-stage compression mechanism, and using the second compression mechanism (120) and the fourth compression mechanism (140) as the high-stage compression mechanism. A refrigeration apparatus comprising a switching mechanism that can be switched to a state used for a high- stage compression mechanism . In any one of claims 7 to 9 ,
The volume ratio changing means (107, 108) is constituted by a switching valve that switches the flow path of the low-pressure refrigerant, intermediate-pressure refrigerant, and high-pressure refrigerant with respect to the compression mechanisms (110, 120, 130, 140). A refrigeration apparatus characterized by. In any one of claims 7 to 9 ,
The volume ratio changing means (107) is configured to change the ratio of the suction volume of the low-stage compression mechanism and the suction volume of the high-stage compression mechanism in accordance with a change in operating conditions. Refrigeration equipment. In any one of claims 1 to 11 ,
A refrigeration apparatus wherein the refrigerant is carbon dioxide.

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