JP2020060108A - Variable displacement compressor and its control valve - Google Patents

Abstract

To improve the operation stability of a control valve for a variable displacement compressor.SOLUTION: A control valve 1 comprises a sub-valve body 36 for opening and closing a sub-passage 10, an operation rod 38 for transmitting a drive force of a solenoid 3 to the sub-valve body 36, and a power element 6 for generating resistance to the solenoid 3 according to a magnitude of suction pressure Ps in an operation chamber 23. The power element 6 includes a first stopper 82, a bellows 45 and a second stopper 84. The sub-valve body 36 has an insertion hole 43 for making the operation rod 38 penetrate it, a communication hole 32 penetrating the sub-valve body 36 in an axial line direction around the insertion hole 43, and a groove part 92 which is recessively formed at an opposing face opposing the second stopper 84, and opened outwardly in a radial direction, and in which the communication hole 32 is opened. In a state that the sub-valve body 36 and the second stopper 84 abut on each other, the sub-passage 10 is formed of a space between the groove part 92 and the second stopper 84 together with the communication hole 32.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a control valve that controls the discharge capacity of a variable capacity compressor.

  BACKGROUND ART An automobile air conditioner is generally configured by arranging a compressor, a condenser, an expansion device, an evaporator and the like in a refrigeration cycle. As the compressor, a variable capacity compressor (also simply referred to as “compressor”) that can change the discharge capacity of the refrigerant is used so that a constant cooling capacity is maintained regardless of the engine speed. The compressor has a rotating shaft driven by an engine. A compression piston is connected to a swash plate attached to the rotary shaft, and the discharge capacity of the refrigerant is adjusted by changing the angle of the swash plate and changing the stroke of the piston. The angle of the swash plate can be continuously changed by introducing a part of the discharged refrigerant into the control chamber of the compressor and changing the balance of pressure applied to both surfaces of the piston. The pressure in the control chamber (hereinafter referred to as "control pressure") is controlled by a control valve (electromagnetic valve) provided between the discharge chamber and the control chamber of the compressor or between the control chamber and the suction chamber. .

  As such a control valve, there is one that controls the control pressure by adjusting the opening degree of the valve portion according to the pressure in the suction chamber (hereinafter referred to as "suction pressure"). This control valve includes a valve body that opens and closes the valve portion, an operating rod that transmits the driving force of the solenoid to the valve body, and a pressure sensitive portion that generates a counter force to the solenoid according to the magnitude of the suction pressure. The valve is opened and closed so that the suction pressure is maintained at the set pressure. The pressure sensitive portion includes a bellows that expands and contracts in the axial direction according to the suction pressure. Generally, the suction pressure is proportional to the temperature of the refrigerant at the outlet of the evaporator, so that by keeping the set pressure constant, the blowing temperature of the air conditioner can be made constant.

  In such a control valve, the actuating rod penetrates the valve body and is coaxially connected to the pressure sensing section, thereby balancing the driving force of the solenoid and the counter force of the pressure sensing section in the axial direction, and Can be maintained at a lift amount corresponding to the set pressure (see, for example, Patent Document 1).

JP, 2017-89832, A

  However, in the configuration of Patent Document 1, the free end of the pressure sensitive portion is supported only by the tip of the operating rod. For this reason, there is room for improvement in terms of operational stability, such as the abutment of the compressor becoming unstable due to vibrations when driving the compressor, and the axes of the two become misaligned, making it difficult to balance the axial forces. It was

  The present invention has been made in view of the above problems, and an object thereof is to improve the operational stability of a control valve for a variable displacement compressor of a suction pressure sensing type.

  An aspect of the present invention is a control valve having a suction chamber, a discharge chamber, and a control chamber, which is applied to a variable displacement compressor in which the discharge capacity is variable by adjusting the pressure of the control chamber. The control valve includes a body having a first pressure chamber communicating with the control chamber, a second pressure chamber communicating with the suction chamber, and a guide hole provided between the first pressure chamber and the second pressure chamber. A valve body that is slidably supported in the guide hole and that opens and closes a communication passage that connects the first pressure chamber and the second pressure chamber, and a solenoid that generates a driving force in an axial direction according to a supply current value, An operating rod for transmitting the driving force of the solenoid to the valve body and the second pressure chamber, the pressure in the second pressure chamber is sensed as a sensed pressure, and the solenoid driving force is determined according to the magnitude of the sensed pressure. A pressure-sensitive portion that generates a counter force against the pressure.

  The pressure-sensitive portion is provided on a base member supported by the body, a bellows that can expand and contract in the axial direction with the base member as a base end, and a tip end of the bellows. And a connecting member. The connecting member has a concave fitting portion that receives the distal end portion of the actuation rod in the axial direction. The actuation rod penetrates the valve body in the axial direction. The valve body is provided with an insertion hole for penetrating the actuation rod, a communication hole provided around the insertion hole and penetrating the valve body in the axial direction, and a recess provided in a surface facing the connecting member to open outward in the radial direction. And a groove portion in which the communication hole is opened. When the valve body is in contact with the connecting member, the space between the groove and the connecting member forms a communication passage together with the communication hole.

  According to this aspect, the valve body is operatively connected to the connecting member. The valve body contacts the connecting member in a region of the surface facing the connecting member except the groove. As a result, the valve body has a structure that supports the connecting member around the operating rod, so that the connected state of the valve body and the pressure-sensitive portion is stabilized. In addition, since the communication passage is always formed between the groove portion of the valve body and the connecting member in the operatively connected state of the both, the flow of the refrigerant according to the opening degree of the valve portion can be secured. As a result, the operational stability of the control valve is improved.

  Another aspect of the present invention is a variable displacement compressor that has a suction chamber, a discharge chamber, and a control chamber, and the discharge capacity is variable by adjusting the pressure of the control chamber with a control valve. The control valve includes a body having a first pressure chamber communicating with the control chamber, a second pressure chamber communicating with the suction chamber, and a guide hole provided between the first pressure chamber and the second pressure chamber, A valve body that is slidably supported in the guide hole and that opens and closes a communication path that connects the first pressure chamber and the second pressure chamber, a solenoid that generates a driving force in an axial direction according to a supply current value, and a solenoid. Is provided in the second pressure chamber, which detects the pressure in the second pressure chamber as the pressure to be sensed, and changes the solenoid drive force according to the magnitude of the pressure to be sensed. And a pressure-sensitive portion that generates a counter force.

  The pressure-sensitive portion is provided on a base member supported by the body, a bellows that can extend and contract in the axial direction with the base member as a base end, and a tip end of the bellows. The pressure-sensitive portion can be operatively connected by abutting on the valve body in the axial direction. And a connecting member. The connecting member has a concave fitting portion that receives the distal end portion of the actuation rod in the axial direction. The actuation rod penetrates the valve body in the axial direction. The valve body is provided with an insertion hole for penetrating the actuation rod, a communication hole provided around the insertion hole and penetrating the valve body in the axial direction, and a recess provided in a surface facing the connecting member to open outward in the radial direction. And a groove portion in which the communication hole is opened. When the valve body is in contact with the connecting member, the space between the groove and the connecting member forms a communication passage together with the communication hole.

  According to this aspect, in the control valve of the variable displacement compressor, the valve body is operatively connected to the connecting member. The valve body contacts the connecting member in a region of the surface facing the connecting member except the groove. As a result, the valve body has a structure that supports the connecting member around the operating rod, so that the connected state of the valve body and the pressure-sensitive portion is stabilized. In addition, since the communication passage is always formed between the groove portion of the valve body and the connecting member in the operatively connected state of the both, the flow of the refrigerant according to the opening degree of the valve portion can be secured. As a result, the operational stability of the control valve and thus the compressor is improved.

  According to the present invention, in the control valve for a variable displacement compressor of the suction pressure sensing type, the operation stability can be improved.

It is a figure showing roughly the refrigerating cycle containing the compressor concerning an embodiment. It is sectional drawing which shows the structure of a control valve. It is a partial expanded sectional view corresponding to the upper half part of FIG. It is a figure showing the structure of a sub valve body. It is a figure showing operation | movement of a control valve.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following description, for convenience, the positional relationship of each structure may be expressed with reference to the illustrated state. In addition, in the following embodiments and modifications thereof, substantially the same components are denoted by the same reference numerals, and the description thereof may be appropriately omitted.

FIG. 1 is a diagram schematically showing a refrigeration cycle including a compressor according to an embodiment.
The compressor 100 is installed in a refrigeration cycle of an automobile air conditioner. The compressor 100 compresses the refrigerant flowing through the refrigeration cycle to produce a high-temperature, high-pressure gas refrigerant and discharges it. The gas refrigerant is condensed in the condenser 111 and further adiabatically expanded by the expansion device 113 to become a low-temperature, low-pressure mist-like refrigerant. This low-temperature, low-pressure refrigerant evaporates in the evaporator 115, and the latent heat of evaporation cools the vehicle interior air. The refrigerant evaporated in the evaporator 115 is returned to the compressor 100 and circulates in the refrigeration cycle. The compressor 100 is provided with a control valve 1 for controlling the discharge capacity of the refrigerant, in addition to a mechanism for compressing the refrigerant in its housing.

  The housing of the compressor 100 is configured by assembling a cylinder block 102, a front housing 104 joined to the front end side of the cylinder block 102, and a rear housing 106 joined to the rear end side of the cylinder block 102. A valve plate 108 is interposed between the cylinder block 102 and the rear housing 106. The cylinder block 102 has a plurality of cylinders 110 around its axis. A control chamber 112 is formed in a space surrounded by the cylinder block 102 and the front housing 104.

  A suction chamber 114, a discharge chamber 116, and a mounting hole 118 are defined inside the rear housing 106. In the rear housing 106, a refrigerant inlet 120 for introducing refrigerant from the evaporator 115 side to the suction chamber 114, a refrigerant outlet 122 for discharging discharged refrigerant from the discharge chamber 116 to the condenser 111 side, a suction chamber 114 and a mounting hole 118. There is provided a communication passage 124 that communicates with the control chamber 112, a communication passage 126 that communicates with the mounting hole 118, and a communication passage 128 that communicates with the discharge chamber 116 and the mounting hole 118.

  A rotary shaft 130 is arranged in the control chamber 112 so as to penetrate the center thereof. The rotating shaft 130 is rotatably supported by a bearing 132 provided on the cylinder block 102 and a bearing 134 provided on the front housing 104. A lug plate 136 is fixed to the rotary shaft 130, and a swash plate 140 is supported via a support arm 138 protruding from the lug plate 136.

  The swash plate 140 is tiltable with respect to the axis of the rotary shaft 130, and is connected to a piston 142 slidably arranged in the plurality of cylinders 110 via shoes 144. A front end portion of the rotary shaft 130 penetrates the front housing 104 and extends to the outside, and a bracket 146 is screwed to the front end portion thereof. Further, a lip seal 148 is provided so as to seal the gap between the front end portion of the rotary shaft 130 and the front housing 104 from the outside. The lip seal 148 prevents the refrigerant gas from leaking along the peripheral surface of the rotary shaft 130 while slidingly contacting the peripheral surface of the rotating shaft 130.

  A bearing 150 is provided at the front end portion of the front housing 104, and a pulley 152 is rotatably supported. The pulley 152 transmits the driving force of the engine to the rotating shaft 130 via the bracket 146.

  The suction chamber 114 communicates with the cylinder 110 via a suction relief valve 154 provided on the valve plate 108, and also communicates with the outlet of the evaporator 115 via the refrigerant inlet 120. The discharge chamber 116 communicates with the cylinder 110 via a discharge relief valve 156 provided on the valve plate 108, and also communicates with an inlet of the condenser 111 via a refrigerant outlet 122. An unillustrated refrigerant passage that connects the control chamber 112 and the suction chamber 114 is provided with an orifice having a fixed cross-sectional area. The orifice has a preset minimum flow rate from the control chamber 112 to the suction chamber 114. Allow the flow.

  The angle of the swash plate 140 is maintained at a position where the loads of the springs 157 and 158 for urging the swash plate 140 in the control chamber 112 and the load due to the pressure applied to both surfaces of the piston 142 connected to the swash plate 140 are balanced. It The angle of the swash plate 140 can be continuously changed by introducing a part of the discharged refrigerant into the control chamber 112 to change the control pressure Pc and changing the balance of pressure applied to both surfaces of the piston 142. it can. By changing the stroke of the piston 142 by changing the angle of the swash plate 140, the discharge capacity of the refrigerant is adjusted. The pressure in the control chamber 112 is controlled by the control valve 1.

  In the compressor 100 configured as described above, the refrigerant gas introduced from the evaporator 115 side into the suction chamber 114 is introduced into the cylinder 110 to be compressed, and the high temperature / high pressure refrigerant from the discharge chamber 116 to the condenser 111 side. Is discharged. A part of the discharged refrigerant is introduced into the control chamber 112 via the control valve 1 and used for capacity control of the compressor 100.

  In the compressor 100, an external circulation path for circulating a refrigeration cycle and an internal circulation path for circulating the inside of the compressor 100 are formed as a refrigerant circulation path. A part of the refrigerant introduced into the cylinder 110 of the compressor 100 leaks to the control chamber 112 through a clearance between the cylinder 110 and the piston 142 as so-called blow-by gas. This blow-by gas also contributes to the internal circulation. The control chamber 112 of this embodiment is a crank chamber.

FIG. 2 is a sectional view showing the structure of the control valve 1.
The control valve 1 is a so-called Ps sensing valve that controls the flow rate of the refrigerant introduced from the discharge chamber 116 to the control chamber 112 so that the suction pressure Ps (corresponding to “sensed pressure”) of the compressor 100 is maintained at a set pressure. It is configured. The control valve 1 is constructed by assembling a valve body 2 and a solenoid 3 in the axial direction. The valve body 2 includes a main valve 7 that opens and closes a refrigerant passage (main passage 9) for introducing a part of the discharged refrigerant into the control chamber 112 when the compressor 100 is operating, and a main valve 7 of the control chamber 112 when the compressor 100 is started. A sub valve 8 for opening and closing a refrigerant passage (sub passage 10) for allowing the refrigerant to escape to the suction chamber 114 is included. The sub valve 8 functions as a so-called bleed valve.

  The solenoid 3 generates a driving force in the valve closing direction of the main valve 7 and the valve opening direction of the auxiliary valve 8 according to the supply current value. The valve body 2 has a stepped cylindrical body 5 in which a main valve 7, a sub valve 8 and a power element 6 are housed. The power element 6 functions as a “pressure sensitive portion” and generates a counter force against the driving force of the solenoid 3 (also referred to as “solenoid force”) according to the magnitude of the suction pressure Ps.

  The body 5 is provided with ports 12, 14 and 16 from the upper end side thereof. The port 12 functions as a “suction chamber communication port” and communicates with the suction chamber 114 of the compressor 100. The port 14 functions as a “control room communication port” and communicates with the control room 112 of the compressor 100. The port 16 functions as a “discharge chamber communication port” and communicates with the discharge chamber 116 of the compressor 100. The end member 13 is fixed so as to close the upper end opening of the body 5. The valve body 2 and the solenoid 3 are fixed by press-fitting the lower end of the body 5 into the upper end of the solenoid 3.

  Inside the body 5, a main passage 9 that communicates the ports 16 and 14 with each other and a sub passage 10 that communicates the ports 14 and 12 with each other are formed. A main valve 7 is provided in the main passage 9, and a sub valve 8 is provided in the sub passage 10. The main passage 9 functions as an “air supply passage”, and the main valve 7 functions as an “air supply valve”. The sub passage 10 functions as a “bleed passage”, and the sub valve 8 functions as a “bleed valve”. The control valve 1 has a configuration in which a power element 6, a sub valve 8, a main valve 7, and a solenoid 3 are sequentially arranged from one end side. A main valve hole 20 and a main valve seat 22 are provided in the main passage 9. A sub valve seat 34 is provided in the sub passage 10.

  The port 12 connects the working chamber 23 defined in the upper portion of the body 5 with the suction chamber 114. The power element 6 is arranged in the working chamber 23. The port 16 introduces the refrigerant having the discharge pressure Pd from the discharge chamber 116. A main valve chamber 24 is provided between the port 16 and the main valve hole 20, and the main valve 7 is arranged therein. The port 14 draws out the refrigerant having the control pressure Pc via the main valve 7 toward the control chamber 112 during the steady operation of the compressor 100, and controls the discharge from the control chamber 112 when the compressor 100 is started. A refrigerant having a pressure Pc is introduced. A sub valve chamber 26 is provided between the port 14 and the main valve hole 20, and the sub valve 8 is arranged therein. The port 12 introduces the refrigerant having the suction pressure Ps during the steady operation of the compressor 100, and at the time of starting the compressor 100, draws the refrigerant having the suction pressure Ps toward the suction chamber 114 via the sub valve 8. . A working chamber 28 is formed between the body 5 and the solenoid 3.

  When the main valve 7 is opened, the port 16 functions as an “introduction port” for introducing the refrigerant from the discharge chamber 116, and the port 14 as an “outlet port” for discharging the refrigerant toward the control chamber 112. Function. On the other hand, when the sub valve 8 is opened, the port 14 functions as an “introduction port” for introducing the refrigerant from the control chamber 112, and the port 12 is an “outlet port” for discharging the refrigerant toward the suction chamber 114. Function as ". The port 14 functions as an “inlet / outlet port” for introducing or discharging the refrigerant according to the open / closed state of the main valve 7 and the sub valve 8.

  The sub valve chamber 26 functions as a “first pressure chamber”, and the working chamber 23 functions as a “second pressure chamber”. The main valve chamber 24 functions as a “third pressure chamber”. The sub passage 10 functions as a “first communication passage” that allows the sub valve chamber 26 and the working chamber 23 to communicate with each other. The main passage 9 functions as a “second communication passage” that connects the main valve chamber 24 and the sub valve chamber 26.

  Cylindrical filter members 15 and 17 are attached to the ports 14 and 16, respectively. The filter members 15 and 17 include a mesh for suppressing the entry of foreign matter into the body 5. When the main valve 7 is opened, the filter member 17 regulates the entry of foreign matter into the port 16, and when the sub valve 8 is opened, the filter member 15 regulates the entry of foreign matter into the port 14.

  A main valve hole 20 is provided between the main valve chamber 24 and the sub valve chamber 26, and a main valve seat 22 is formed at the lower end opening end thereof. A guide hole 25 (first guide hole) is provided between the sub valve chamber 26 and the working chamber 23. A guide hole 27 (second guide hole) is provided between the main valve chamber 24 and the working chamber 28. The valve driving body 29 is slidably inserted into the guide hole 27.

  The valve driving body 29 has a stepped cylindrical shape, and an upper half portion thereof has a reduced diameter to form a partition portion 33 that penetrates the main valve hole 20 and partitions the inside and the outside. The step portion formed in the intermediate portion of the valve drive body 29 constitutes the main valve body 30. The main valve element 30 is attached to and detached from the main valve chamber 24 side to the main valve seat 22 to open and close the main valve 7 to adjust the flow rate of the refrigerant flowing from the discharge chamber 116 to the control chamber 112. An upper portion of the partition portion 33 has a diameter that increases upward in a tapered shape, and a sub-valve seat 34 is formed at an upper end opening portion thereof. The sub valve seat 34 functions as a movable valve seat that is displaced together with the valve driver 29. Although the valve drive body 29 and the main valve body 30 are distinguished from each other in the present embodiment, the entire valve drive body 29 may be regarded as the “main valve body”.

  On the other hand, the auxiliary valve body 36 is slidably inserted into the guide hole 25. The sub valve body 36 has a cylindrical shape and has a plurality of communication holes 32 around the axis. These communication holes 32 form a part of the sub passage 10, and open the sub valve 8 to connect the sub valve chamber 26 and the working chamber 23. The sub-valve element 36 and the sub-valve seat 34 are arranged to face each other in the axial direction. The sub valve body 36 is attached to and detached from the sub valve seat 34 in the sub valve chamber 26 to open and close the sub valve 8.

  Further, an elongated actuation rod 38 is provided along the axis of the body 5. The operating rod 38 penetrates the sub valve body 36 and extends toward the power element 6 side. The lower end of the operating rod 38 is connected to a plunger 50 of the solenoid 3 which will be described later. The upper half of the operating rod 38 penetrates the valve driving body 29, and the upper portion thereof has a reduced diameter. The sub valve body 36 is externally inserted into the reduced diameter portion and fixed by press fitting. The tip of the reduced diameter portion extends to the power element 6 side.

  A ring-shaped spring bearing 40 is fitted and supported at the axially intermediate portion of the operating rod 38. A spring 42 (which functions as a “biasing member”) that biases the valve drive body 29 in the valve closing direction of the main valve 7 is interposed between the valve drive body 29 and the spring receiver 40. When the main valve 7 is controlled, the elastic force of the spring 42 causes the valve drive body 29 and the spring receiver 40 to be in a tensioned state, and the main valve body 30 and the operating rod 38 operate integrally.

  The power element 6 includes a bellows 45 that is displaced by sensing the suction pressure Ps, and the displacement of the bellows 45 generates a counter force against the solenoid force. This counter force is also transmitted to the main valve body 30 via the sub valve body 36. When the sub valve body 36 is seated on the sub valve seat 34 and closes the sub valve 8, the relief of the refrigerant from the control chamber 112 to the suction chamber 114 is blocked. Further, the sub valve body 36 is separated from the sub valve seat 34 and the sub valve 8 is opened, so that the relief of the refrigerant from the control chamber 112 to the suction chamber 114 is allowed.

  On the other hand, the solenoid 3 includes a stepped cylindrical core 46, a bottomed cylindrical sleeve 48 assembled so as to seal a lower end opening of the core 46, and the core 48 accommodated in the sleeve 48 in the axial direction. A stepped cylindrical plunger 50, a cylindrical bobbin 52 externally fitted to the core 46 and the sleeve 48, an electromagnetic coil 54 wound around the bobbin 52 and generating a magnetic circuit by energization. A cylindrical case 56 provided so as to cover the electromagnetic coil 54 from the outside, an end member 58 provided so as to seal the lower end opening of the case 56, and embedded in the end member 58 below the bobbin 52. And a collar 60 made of a magnetic material. The core 46, the case 56, and the collar 60 form a yoke. The body 5, the end member 13, the core 46, the case 56, and the end member 58 form the body of the entire control valve 1.

  The valve body 2 and the solenoid 3 are fixed by press-fitting the lower end portion of the body 5 into the upper end opening portion of the core 46. The working chamber 28 is formed between the core 46 and the valve driving body 29. On the other hand, the operating rod 38 is inserted so as to penetrate the center of the core 46 in the axial direction. The working chamber 28 communicates with the working chamber 23 via the respective internal passages of the valve driving body 29 and the sub valve body 36. Therefore, the suction pressure Ps of the working chamber 23 is introduced into the working chamber 28. The suction pressure Ps is also guided to the inside of the sleeve 48 through the communication passage 62 formed by the gap between the operating rod 38 and the core 46.

  A spring 44 (which functions as an “urging member”) is interposed between the core 46 and the plunger 50 so as to urge the core 46 and the plunger 50 in a direction in which they are separated from each other. The spring 44 functions as a so-called off spring that opens the main valve 7 when the solenoid 3 is off. The operating rod 38 is coaxially connected to each of the sub valve body 36 and the plunger 50. The operating rod 38 has an upper portion press-fitted into the sub valve body 36 and a lower end portion press-fitted into an upper portion of the plunger 50. The actuating rod 38, the sub valve body 36, and the plunger 50 constitute a “movable member” that is integrally displaced with the valve drive body 29 when the main valve 7 is controlled.

  The operating rod 38 appropriately transmits a solenoid force, which is a suction force between the core 46 and the plunger 50, to the main valve body 30 and the sub valve body 36. On the other hand, the actuating rod 38 is loaded with a driving force (also referred to as “pressure-sensitive driving force”) due to the expansion and contraction of the power element 6 so as to oppose the solenoid force. That is, in the control state of the main valve 7, the force adjusted by the solenoid force and the pressure-sensitive driving force acts on the main valve body 30 to appropriately control the opening degree of the main valve 7. When the compressor 100 is started, the operating rod 38 is displaced against the urging force of the spring 44 according to the magnitude of the solenoid force, and after closing the main valve 7, the sub valve body 36 is pushed up and the sub valve 8 is opened. Let me speak. Further, even when the main valve 7 is being controlled, when the suction pressure Ps is considerably increased, the operating rod 38 is displaced against the biasing force of the bellows 45, and the main valve 7 is closed and then the sub valve body 36 is pushed up. To open the sub valve 8. Thereby, the bleed function is exerted.

  The sleeve 48 is made of a non-magnetic material. A communication groove 66 that is parallel to the axis is provided on the side surface of the plunger 50, and a communication hole 68 that communicates the inside and the outside is provided in the lower portion of the plunger 50. With this configuration, the suction pressure Ps is guided to the back pressure chamber 70 through the gap between the plunger 50 and the sleeve 48 even when the plunger 50 is located at the bottom dead center as shown in the figure.

  A pair of connection terminals 72 connected to the electromagnetic coil 54 extends from the bobbin 52 and penetrates the end members 58 to be drawn out to the outside. For convenience of description, only one of the pair is shown in the figure. The end member 58 is attached so as to cover the entire structure inside the solenoid 3 contained in the case 56 from below. The end member 58 is formed by molding (injection molding) a resin material having corrosion resistance, and the resin material is also present in the gap between the case 56 and the electromagnetic coil 54. Thereby, the heat generated in the electromagnetic coil 54 is easily transferred to the case 56, and the heat dissipation performance thereof is improved. A tip portion of the connection terminal 72 is pulled out from the end member 58 and is connected to an external power source (not shown).

FIG. 3 is a partially enlarged sectional view corresponding to the upper half of FIG. FIG. 4 is a diagram showing the structure of the sub valve body 36. (A) is a plan view and (B) is a sectional view taken along the line AA of (A).
As shown in FIG. 3, a labyrinth seal 74 including a plurality of annular grooves is provided on the sliding surface of the valve driving body 29 with the guide hole 27 so as to suppress the flow of the refrigerant. The spring receiver 40 is composed of a so-called E-ring, is supported so as to fit into an annular groove formed in the intermediate portion of the operating rod 38, and is disposed inside the operating chamber 28.

  The power element 6 is configured by closing the upper end opening of the bellows 45 with a first stopper 82 and closing the lower end opening with a second stopper 84. The first stopper 82 functions as a “base member”, and the second stopper 84 functions as a “connecting member”. The first stopper 82 is integrally molded with the end member 13 and functions as a base end (fixed end) of the bellows 45. The second stopper 84 is displaced in the axial direction as the bellows 45 expands and contracts, and functions as a free end of the bellows 45. The second stopper 84 is operatively connected to the operating rod 38 by abutting on the auxiliary valve body 36 in the axial direction.

  The second stopper 84 is formed by pressing a metal material into a bottomed cylindrical shape, and has a flange portion 86 extending outward in the radial direction at the opening end thereof. The cylindrical portion of the second stopper 84 is a concave fitting portion 87. The upper end opening of the bellows 45 is airtightly welded to the flange portion 86 of the first stopper 82, and the lower end opening is airtightly welded to the flange portion 86 of the second stopper 84. The inside of the bellows 45 is a sealed reference pressure chamber S. Inside the bellows 45, a spring 88 for urging the bellows 45 in the extension direction is interposed between the first stopper 82 and the second stopper 84. The reference pressure chamber S is in a vacuum state in this embodiment.

  By adjusting the amount of press-fitting of the end member 13 into the body 5, the set load of the power element 6 (set load of the spring 88) can be adjusted.

  The central portion of the first stopper 82 extends downward toward the inside of the bellows 45, the central portion of the second stopper 84 extends upward toward the inside of the bellows 45, and they are the shafts of the bellows 45. It forms the core. The upper end of the operating rod 38 is coaxially inserted (i.e., loosely fitted) into the concave fitting portion 87 of the second stopper 84. The bellows 45 expands or contracts in the axial direction (opening and closing directions of the main valve 7 and the sub valve 8) according to the pressure difference between the suction pressure Ps of the working chamber 23 and the reference pressure of the reference pressure chamber S. Driving force in the valve closing direction of the sub valve body 36 and the valve opening direction of the main valve body 30 is applied according to the expansion of the bellows 45. Even if the differential pressure becomes large, when the bellows 45 contracts by a predetermined amount, the second stopper 84 comes into contact with the first stopper 82 and is locked, so that the contraction is restricted.

  As shown in FIG. 4 (A), the sub-valve body 36 has an insertion hole 43 penetrating the center thereof in the axial direction. Four communication holes 32 are provided around the insertion hole 43. These communication holes 32 are arranged at intervals of 90 degrees about the axis of the sub valve body 36 and penetrate the sub valve body 36 in the axial direction. A cross-shaped groove 92 is provided on the upper surface of the sub valve body 36 (the surface facing the second stopper 84). The groove portion 92 is open radially outward in all directions. An insertion hole 43 is opened at the center of the bottom surface of the groove 92. A communication hole 32 is opened in each bottom surface extending in all directions.

  The remaining portion of the upper surface of the sub valve body 36, excluding the groove portion 92, becomes the contact surface 90 with the second stopper 84. These abutting surfaces 90 are distributed in four regions radially separated from the insertion hole 43, and are arranged along the peripheral portion of the sub valve body 36 in the present embodiment. These contact surfaces 90 stably support the second stopper 84 at four points equidistant from the center thereof. As shown in FIG. 4B, a labyrinth seal 75 is provided on the outer peripheral surface (sliding surface with the guide hole 25) of the sub valve body 36.

  Returning to FIG. 3, the auxiliary valve body 36 is positioned with respect to the operating rod 38 by being locked to the stepped portion 79 which is the base end of the reduced diameter portion of the operating rod 38. When the solenoid 3 is switched from OFF to ON, the auxiliary valve body 36 contacts the second stopper 84, so that the auxiliary valve body 36 and the power element 6 are operatively connected. When the main valve 7 is opened, the valve driving body 29 is pressed against the sub valve body 36 by the urging force of the spring 42, so that the driving force of the power element 6 is also transmitted to the main valve body 30.

  The concave fitting portion 87 of the second stopper 84 coaxially receives the tip end portion of the operating rod 38. However, the contact surface 90 of the sub valve body 36 is locked to the flange portion 86 of the second stopper 84 so that the tip of the operating rod 38 does not abut the bottom portion of the second stopper 84. . In other words, the power element 6 and the sub-valve body 36 are set by setting the length at which the upper end of the operating rod 38 does not abut against the second stopper 84 (or the depth of the concave fitting portion 87 is set). The contact with is secured.

  Since the contact surface 90 and the flange portion 86 of the sub valve body 36 contact each other, the second stopper 84 can be stably supported in the axial direction. That is, since the sub-valve element 36 abuts the second stopper 84 in a surface contact manner at a plurality of locations apart from the axis of the second stopper 84, it is possible to prevent the second stopper 84 from flapping. As a result, lateral runout of the bellows 45 can be prevented. On the other hand, even if the sub-valve element 36 separates from the second stopper 84 by turning the solenoid 3 from ON to OFF, the operating rod 38 serves as the axis of the second stopper 84 and prevents or suppresses lateral runout of the bellows 45. can do. The same applies when the bellows 45 contracts due to the increase in the suction pressure Ps and the second stopper 84 separates from the sub valve body 36. With such a configuration, the durability of the bellows 45 can be improved.

  Even in the state where the sub valve body 36 and the second stopper 84 are in contact with each other, the space between the groove 92 and the second stopper 84 forms the sub passage 10 together with the plurality of communication holes 32. That is, since the sub passage 10 is always formed in the operatively connected state of both, the flow of the refrigerant corresponding to the opening degree of the sub valve 8 can be secured. As a result, the operational stability of the control valve 1 can be maintained.

  The operating rod 38 is arranged such that, in the illustrated state in which the sub valve body 36 is seated on the sub valve seat 34, the upper surface of the spring receiver 40 is separated from the lower surface of the valve drive body 29 by at least a predetermined distance L, The position of the stepped portion 79 is set. The interval L functions as so-called "play".

  The main valve chamber 24 is provided coaxially with the body 5 and is configured as a pressure chamber having a diameter larger than that of the main valve hole 20. Therefore, a relatively large space is formed between the main valve 7 and the port 16, and a sufficient flow rate of the refrigerant flowing through the main passage 9 can be secured when the main valve 7 is opened. Similarly, the sub valve chamber 26 is also provided coaxially with the body 5 and is configured as a pressure chamber having a diameter larger than that of the main valve hole 20. Therefore, a relatively large space is formed between the sub valve 8 and the port 14. As shown in the figure, the attachment / detachment portion between the upper end of the valve drive body 29 and the lower end of the sub valve body 36 is located in the intermediate portion of the sub valve chamber 26. That is, the movable range of the main valve body 30 is set so that the sub valve seat 34 is always located in the sub valve chamber 26, and the sub valve 8 is opened and closed in the sub valve chamber 26. Therefore, when the sub valve 8 is opened, a sufficient flow rate of the refrigerant flowing through the sub passage 10 can be secured. That is, the bleed function can be effectively exhibited.

Next, the operation of the control valve will be described.
In this embodiment, a PWM (Pulse Width Modulation) method is used for controlling the energization of the solenoid 3. This PWM control is performed by supplying a pulse current of about 400 Hz set to a predetermined duty ratio and is controlled by a control unit (not shown). This control unit has a PWM output unit that outputs a pulse signal with a specified duty ratio, but since a known configuration is adopted for the configuration itself, detailed description thereof will be omitted.

  FIG. 5 is a diagram showing the operation of the control valve. FIG. 3 already described shows the minimum capacity operating state of the control valve. FIG. 5 shows a state in which the bleed function is operated when the control valve is activated. In the following, description will be made based on FIG. 2 with reference to FIGS. 3 and 5 as appropriate.

  When the solenoid 3 of the control valve 1 is not energized (OFF), that is, when the automobile air conditioner is not operating, the suction force does not act between the core 46 and the plunger 50. On the other hand, the urging force of the spring 44 is transmitted to the valve driving body 29 via the plunger 50, the operating rod 38 and the sub valve body 36. As a result, as shown in FIG. 3, the main valve body 30 is separated from the main valve seat 22 and the main valve 7 is fully opened. At this time, the auxiliary valve 8 maintains the closed state. The sub valve body 36 is separated from the second stopper 84.

  On the other hand, when a starting current is supplied to the electromagnetic coil 54 of the solenoid 3 at the time of starting the automobile air conditioner, as shown in FIG. 5, the suction pressure Ps is determined by the value of the supplied current. (Also referred to as “pressure”), the sub valve 8 opens. That is, the solenoid force overcomes the urging force of the spring 42, and the sub valve body 36 is integrally pushed up. As a result, the sub valve body 36 is separated from the sub valve seat 34, the sub valve 8 is opened, and the bleed function is effectively exhibited. In this operation process, the main valve body 30 is pushed up by the urging force of the spring 42 and seated on the main valve seat 22. As a result, the main valve 7 is closed. That is, after the main valve 7 is closed to regulate the introduction of the discharged refrigerant into the control chamber 112, the sub valve 8 is opened to quickly relieve the refrigerant in the control chamber 112 into the suction chamber 114. As a result, the compressor 100 can be quickly started. It should be noted that the "sub valve opening pressure" changes in accordance with a change in a set pressure Pset described later depending on the environment in which the vehicle is placed.

  When the current value supplied to the solenoid 3 is within the control current value range of the main valve 7, the opening degree of the main valve 7 is autonomously adjusted so that the suction pressure Ps becomes the set pressure Pset set by the supply current value. It In the control state of the main valve 7, the sub valve body 36 is seated on the sub valve seat 34, and the sub valve 8 maintains the closed state. On the other hand, since the suction pressure Ps is relatively low, the bellows 45 extends and the main valve body 30 operates to adjust the opening degree of the main valve 7. At this time, the main valve body 30 is at a valve lift position where the force in the valve opening direction by the spring 44, the solenoid force in the valve closing direction, and the force in the valve opening direction by the power element 6 according to the suction pressure Ps are balanced. Stop. At this time, as described above, the power element 6 is stably supported by the sub valve body 36.

  Then, for example, when the refrigeration load becomes large and the suction pressure Ps becomes higher than the set pressure Pset, the bellows 45 shrinks, so that the main valve body 30 is displaced relatively upward (in the valve closing direction). As a result, the valve opening of the main valve 7 becomes smaller, and the compressor 100 operates so as to increase the discharge capacity. As a result, the suction pressure Ps changes in the decreasing direction. On the contrary, when the refrigeration load becomes small and the suction pressure Ps becomes lower than the set pressure Pset, the bellows 45 expands. As a result, the power element 6 biases the main valve body 30 in the valve opening direction to increase the valve opening of the main valve 7, and the compressor 100 operates to reduce the discharge capacity. As a result, the suction pressure Ps is maintained at the set pressure Pset.

  When the load of the engine increases while such a steady control is performed and it is desired to reduce the load on the air conditioner, the solenoid 3 in the control valve 1 is switched from on to off. Then, since the suction force does not act between the core 46 and the plunger 50, the main valve body 30 is separated from the main valve seat 22 by the biasing force of the spring 44, and the main valve 7 is fully opened. At this time, since the sub valve body 36 is basically seated on the sub valve seat 34, the sub valve 8 is closed. As a result, the refrigerant having the discharge pressure Pd introduced from the discharge chamber 116 of the compressor 100 into the port 16 passes through the fully opened main valve 7 and flows from the port 14 to the control chamber 112. Therefore, the control pressure Pc becomes high, and the compressor 100 starts the minimum capacity operation.

  As described above, in the present embodiment, the sub valve body 36 is operatively connected to the second stopper 84. The sub-valve element 36 contacts the second stopper 84 in a surface contact mode in a region of the upper surface excluding the groove portion 92. Since the sub valve body 36 supports the second stoppers 84 at a plurality of points in a relatively wide area around the actuation rod 38, the connection state between the sub valve body 36 and the power element 6 is stable. Further, since the sub passage 10 is always formed between the groove portion 92 of the sub valve body 36 and the second stopper 84 in the operatively connected state of both, the flow of the refrigerant according to the opening degree of the sub valve 8 can be secured. . As a result, the operational stability of the control valve 1 is improved.

  Although the preferred embodiment of the present invention has been described above, the present invention is not limited to the specific embodiment, and it goes without saying that various modifications can be made within the scope of the technical idea of the present invention. Absent.

  In the embodiment described above, as shown in FIG. 4A, the groove 92 communicates with the opening end of the insertion hole 43, that is, the insertion hole 43 opens in the groove 92. In the modification, the groove 92 may not extend to the insertion hole 43, that is, the insertion hole 43 may not be opened to the groove 92. Further, in the above-described embodiment, the example in which the communication hole 32 is opened on the bottom surface of the groove portion 92 is shown, but it may be opened on the side surface of the groove portion 92. Alternatively, the communication hole 32 may be opened so as to straddle the bottom surface and the side surface of the groove 92.

  In the above-described embodiment, the example in which the groove 92 is formed in a cross shape is shown, but it goes without saying that the groove 92 may be formed in another shape. It goes without saying that the numbers of the communication holes 32 and the contact surfaces 90 are not limited to those shown in the figures.

  Although the contact surface 90 is provided along the peripheral portion of the sub-valve body 36 in the above-described embodiment, the contact surface may be formed without chamfering the peripheral edge. However, it is possible to support the connecting member more stably if the plurality of contact surfaces are provided in a position more distant from the center (axis) of the connecting member in a well-balanced manner.

  It should be noted that the present invention is not limited to the above-described embodiments and modifications, and the constituent elements can be modified and embodied without departing from the scope of the invention. Various inventions may be formed by appropriately combining a plurality of constituent elements disclosed in the above-described embodiments and modifications. Further, some constituent elements may be deleted from all the constituent elements shown in the above-described embodiment and modified examples.

1 control valve, 2 valve body, 3 solenoid, 5 body, 6 power element, 7 main valve, 8 sub valve, 9 main passage, 10 sub passage, 12 port, 13 end member, 14 port, 16 port, 20 main valve Hole, 22 main valve seat, 23 working chamber, 24 main valve chamber, 25 guide hole, 26 auxiliary valve chamber, 27 guide hole, 28 working chamber, 29 valve driver, 30 main valve body, 32 communicating hole, 34 auxiliary valve Seat, 36 sub valve body, 38 actuating rod, 43 insertion hole, 45 bellows, 46 core, 50 plunger, 82 first stopper, 84 second stopper, 86 flange portion, 87 concave fitting portion, 89 support portion, 90 Interface, 92 groove, S reference pressure chamber, 100 compressor.

Claims (6)

A control valve having a suction chamber, a discharge chamber and a control chamber, wherein the control valve is applied to a variable displacement compressor in which the discharge capacity is variable by adjusting the pressure of the control chamber,
A body having a first pressure chamber communicating with the control chamber, a second pressure chamber communicating with the suction chamber, and a guide hole provided between the first pressure chamber and the second pressure chamber,
A valve body slidably supported in the guide hole and opening and closing a communication passage that connects the first pressure chamber and the second pressure chamber to each other;
A solenoid that generates a driving force in the axial direction according to the supply current value,
An actuation rod for transmitting the driving force of the solenoid to the valve body,
A pressure sensitive unit that is provided in the second pressure chamber, senses the pressure of the second pressure chamber as a sensed pressure, and generates a counter force against the driving force of the solenoid according to the magnitude of the sensed pressure; ,
Equipped with
The pressure sensitive portion is
A base member supported by the body,
A bellows which is axially expandable and contractible with the base member as a base end,
A connecting member which is provided at the tip of the bellows and which can be operatively connected by contacting the valve body in the axial direction;
Including,
The connecting member has a concave fitting portion that receives the distal end portion of the operating rod in the axial direction,
The actuation rod penetrates the valve body in the axial direction,
The valve body is
An insertion hole for penetrating the operating rod,
A communication hole provided around the insertion hole and penetrating the valve body in the axial direction,
A groove portion which is provided in a surface facing the connecting member so as to be opened outward in the radial direction, and in which the communication hole is open;
Have
A control valve, wherein a space between the groove and the connecting member forms the communication passage together with the communication hole when the valve body is in contact with the connecting member.   The control valve according to claim 1, wherein a plurality of the communication holes are provided around the insertion hole.   The abutment surface of the valve element with the connecting member is distributed in a plurality of regions radially separated from the insertion hole on the surface facing the connecting member. The control valve described.   The control valve according to claim 3, wherein the contact surface is arranged along a peripheral edge portion of a surface of the valve body facing the connecting member.   The control valve according to claim 1, wherein the groove portion communicates with an opening end of the insertion hole. A variable capacity compressor having a suction chamber, a discharge chamber and a control chamber, wherein the discharge capacity is variable by adjusting the pressure of the control chamber by a control valve,
The control valve is
A body having a first pressure chamber communicating with the control chamber, a second pressure chamber communicating with the suction chamber, and a guide hole provided between the first pressure chamber and the second pressure chamber,
A valve body slidably supported in the guide hole and opening and closing a communication passage that connects the first pressure chamber and the second pressure chamber to each other;
A solenoid that generates a driving force in the axial direction according to the supply current value,
An actuation rod for transmitting the driving force of the solenoid to the valve body,
A pressure sensitive unit that is provided in the second pressure chamber, senses the pressure of the second pressure chamber as a sensed pressure, and generates a counter force against the driving force of the solenoid according to the magnitude of the sensed pressure; ,
Equipped with
The pressure sensitive portion is
A base member supported by the body,
A bellows which is axially expandable and contractible with the base member as a base end,
A connecting member which is provided at the tip of the bellows and which can be operatively connected by contacting the valve body in the axial direction;
Including,
The connecting member has a concave fitting portion that receives the distal end portion of the operating rod in the axial direction,
The actuation rod penetrates the valve body in the axial direction,
The valve body is
An insertion hole for penetrating the operating rod,
A communication hole provided around the insertion hole and penetrating the valve body in the axial direction,
A groove portion which is provided in a surface facing the connecting member so as to be opened outward in the radial direction, and in which the communication hole is open;
Have
A variable displacement compressor, wherein a space between the groove and the connecting member forms the communication passage together with the communication hole when the valve body is in contact with the connecting member.

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