JP3643937B2 - Vane pump - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a vane pump, and more particularly, to a vane pump that is used by being mounted on an automobile as a source of operating hydraulic pressure in various hydraulic operating devices.
[0002]
[Prior art]
2. Description of the Related Art Recent automobiles are equipped with various devices that operate by hydraulic pressure, such as power steering devices and automatic transmissions, and are equipped with various hydraulic pumps as a source of operating hydraulic pressure in these devices. As this type of hydraulic pump, conventionally known vane pumps are widely used as a kind of rotary positive displacement pumps.
[0003]
The vane pump closes both sides of an uneven cam ring having a plurality of (two to three) recesses at substantially equal intervals on the inner periphery with a pair of side plates. A rotor having a plurality of vanes that can be moved back and forth in the radial direction at substantially equal positions in the circumferential direction, and a fitting circumference between the rotor and the cam ring. The pump chambers are arranged in parallel at the corresponding positions of the concave portion.
[0004]
The rotor rotates coaxially inside the cam ring by the rotation of the drive shaft fitted to the shaft center portion. Each vane provided in the rotor is urged outward in the radial direction and is pressed against the inner peripheral surface of the cam ring. It is designed to rotate. Each of the pump chambers arranged outside the rotor is formed with a suction port that opens to the upstream side in the rotational direction of the rotor and a discharge port that also opens to the downstream side.
[0005]
Thus, when the rotor rotates inside the cam ring, in each of the pump chambers, the working oil (working fluid) sucked from the suction port on one side passes through the suction port and is adjacent to each other. A pump operation is performed in which the pressure is received between the vanes of the sheet, and the pressure is increased by rotating in a state of being confined between the vanes, and the air is discharged from the discharge port at a rotational position where the discharge port opens in the confinement space between the vanes. .
[0006]
[Problems to be solved by the invention]
The vane pump as described above is a positive displacement pump, and the above-described pump operation is not continuously performed, so that pulsation occurs in the piping system connected to the discharge side, and an unpleasant operation sound due to this pulsation occurs. In order to solve this problem, JP-A-57-108484, JP-A-58-170868, and JP-A-59-49385 disclose the outer wall of the pump chamber. There is disclosed a vane pump in which the shape of a recess on the inner periphery of a cam ring to be formed is devised.
[0007]
However, these disclosures finely define the local radius of curvature and angle of the recess. On the other hand, in the vane pump used as the hydraulic power source of the hydraulic operating device of the automobile, near the engine serving as the driving source. In recent years, small vane pumps with an outer diameter of the rotor and an inner diameter of the cam ring of around 30 mm have been adopted. In the vane pump, there is a problem in that the disclosed contents described above are realized with great difficulty, and the effect of suppressing the operation noise is low.
[0008]
Furthermore, a vane pump used as a hydraulic power source of a hydraulic operation device of an automobile needs to be rotated at a high speed in order to obtain the pressure and flow rate necessary for the operation of the target device while achieving the above-described miniaturization. As driving speed increases, driving noise tends to increase, and suppression of driving noise is an important issue.
[0009]
SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and a vane pump capable of effectively reducing the generation of operation noise and capable of quiet operation at high speed with a simple configuration that can be realized regardless of downsizing. The purpose is to provide.
[0010]
[Means for Solving the Problems]
The vane pump according to the present invention has a short cylindrical rotor provided with a plurality of vanes arranged substantially equally in the circumferential direction so as to be movable back and forth in the radial direction inside the cam ring having an uneven annular shape. A plurality of pump chambers are formed on the circumference, and the fluid sucked into each pump chamber from one side in the circumferential direction is confined between adjacent vanes, and the pressure is increased by rotating the rotor by rotating the rotor. The vane pump that discharges from the other side includes a communication path that connects the plurality of pump chambers to each other at a circumferential position that should become a confinement space for fluid between the vanes.
[0011]
[Action]
In the present invention, a plurality of pump chambers formed between the cam ring and the rotor are confined between adjacent vanes by shutting off the fluid inside them from the suction ports and the discharge ports on both sides in the circumferential direction. By communicating with each other at the circumferential position to be generated, equalizing the internal pressure of each confined space, and suppressing the generation of sound due to uneven pressure in the circumferential direction of the rotor, Effectively reduce the occurrence.
[0012]
【Example】
Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments thereof. FIG. 1 is a side sectional view showing an embodiment of a vane pump according to the present invention, and FIG. 2 is a transverse sectional view taken along line II-II in FIG.
[0013]
In the figure, reference numeral 1 denotes a short cylindrical rotor. The rotor 1 is configured so that a plurality of plate-like vanes 10, 10... Can be moved back and forth in a radial direction at substantially equal positions in the circumferential direction. I have. Reference numeral 2 denotes an uneven-walled annular shape having an inner peripheral surface in which two concave portions are substantially equally arranged in the circumferential direction in a slightly larger circle than the rotor 1 and a circular outer peripheral surface sufficiently larger than this. The cam ring 2 is fitted into a cavity 40 formed in the housing 4 with the pressure plate 3 as an inner back side, together with a thick disc-shaped pressure plate 3 stacked on one side. As shown in FIG. 2, it is positioned in the circumferential direction by fixing pins 30 and 30 which are driven into the fitting portion.
[0014]
In this way, the cavity 40 of the housing 4 that encloses the cam ring 2 is closed by the end plate 5 that is fixed to the opening side periphery of the cavity 40 by a plurality of fixing bolts 51, 51. Is housed in the inner space of the cam ring 2 sandwiched on both sides by the pressure plate 3 and the end plate 5, and is splined to the rotor shaft 6 that penetrates the axial center of the pressure plate 3 and protrudes into the space. .
[0015]
The housing 4 includes a shaft support hole 41 that is coaxial with the cavity 40 and penetrates to the other side. The rotor shaft 6 is supported by a ball bearing 42 fitted in the shaft support hole 41 at one side where the rotor 1 is fitted, and the other side is fixed at the axial center position of the end plate 5. It is supported by the bush 50 and protrudes to the outside of the shaft support hole 41 for an appropriate length, and is connected to a drive source (not shown) via a V-belt wheel 60 fitted to the protruding end. The spline-coupled rotor 1 is coaxially rotated inside the cam ring 2 by transmission from the drive source.
[0016]
With the above configuration, between the outer peripheral surface of the rotor 1 and the inner peripheral surface of the cam ring 2, each of the formation positions of the concave portions substantially equally arranged in the circumferential direction of the latter has a shape as shown in FIG. 2. The two pump chambers P, P are formed by closing both sides with the pressure plate 3 and the end plate 5. A suction oil passage 20 connected to a suction pipe S fixed to the outer periphery of the housing 4 is formed in the end plate 5 that closes one side of both pump chambers P, P. The suction oil passage 20 is shown in FIG. As shown in FIG. 3, the pump chambers P are connected to the inside of the pump chambers P by separate suction ports 21 that open upstream in the rotational direction of the rotor 1.
[0017]
The vanes 10, 10... Held by the rotor 1 are urged outward in the radial direction by, for example, pressure oil introduced into the separate guide grooves for guiding in the radial direction. When the rotor 1 rotates together with the rotor shaft 6, the rotor 1 rotates with the rotor 1 while moving forward and backward separately following the shape change of the inner peripheral surface of the cam ring 2. .
[0018]
As a result of this rotation, the hydraulic oil supplied to the suction oil passage 20 via the suction pipe S is sucked into the pump chambers P and P via the separate suction ports 21 and 21, respectively. It is received between the vanes 10 and 10 adjacent to each other in the direction, and is rotated with the rotation of the rotor 1 to increase the pressure.
[0019]
On the other hand, the pressure plate 3 that closes the other side of the pump chambers P, P has a reverse side of the position where the suction ports 21, 21 are formed, that is, the rotational direction of the rotor 1, as shown by a two-dot chain line in FIG. The discharge ports 22 and 22 that open into the pump chambers P and P are formed in the downstream side of the pump chamber P, and the pump chambers P and P are formed on the back side of the pressure plate 3 by the discharge ports 22 and 22. The pressure chamber 23 is connected to the pressure chamber 23.
[0020]
Thus, the hydraulic oil that rotates together with the adjacent vanes 10 and 10 in each pump chamber P and P is discharged to the pressure chamber 23 through the discharge ports 22 and 22, and further communicates with the pressure chamber 23. It is sent to the outside through the valve chamber 24. In addition, a flow control valve (not shown) is built in the valve chamber 24, and a part of the discharged oil introduced into the valve chamber 24 is returned to the suction oil passage 20 by the operation of the flow control valve, The amount of oil delivered to is kept substantially constant.
[0021]
The vane pump according to the present invention that operates as described above includes a communication passage 7 that allows two pump chambers P, P arranged inside the cam ring 2 to communicate with each other. As shown in FIG. 2, the communication path 7 circulates on the mating surface of the cam ring 2 with the pressure plate 3 over the outer sides of the pump chambers P, P, and is bent radially inward at both ends. The pump chambers P and P communicate with each other at a substantially central position.
[0022]
FIG. 3 is an enlarged cross-sectional view showing a portion where the communication path 7 is formed. As shown in this figure, the communication path 7 has an opening portion of a concave groove 7a formed on the end face of the cam ring 2 at the end face. The communication passage 7 can be easily obtained by the simultaneous formation of the concave groove 7a at the time of forming the cam ring 2 by sintering. Further, it is also possible to obtain the communication path 7 as a closed path in which a similar groove is formed on the pressure plate 3 side and the opening of the groove is closed by the end face of the cam ring 2.
[0023]
Further, as described above, the discharge ports 22 and 22 are opened in the pressure plate 3, and fixing pins 30 for fixing to the housing 4 are provided on the outer peripheral portions of the cam ring 2 and the pressure plate 3. The formation of the communication path 7 needs to be performed while avoiding these corresponding parts, but this is also easily achieved by the formation of the communication path 7 in the embodiment shown in FIG.
[0024]
FIG. 4 is a plan development view of the pump chamber P for explaining the pump operation performed as described above. When attention is paid to a space A between two specific vanes 10, 10... Among the plurality of vanes 10, 10. The internal relative position is sequentially changed, and hydraulic oil is received when it is in a circumferential position communicating with the opening of the suction port 21 as shown in FIG. 4 (a), and the opening of the discharge port 22 as shown in FIG. 4 (c). When it is in a circumferential position that communicates with the part, it is discharged.
[0025]
In order to obtain a predetermined oil pressure during such discharge, the space A between the vanes 10 and 10 is sucked as shown in FIG. 4 (b) at an intermediate position between FIGS. 4 (a) and 4 (c). It is necessary to become a confined space A ′ for confining hydraulic oil without communicating with any of the port 21 and the discharge port 22, and such a confined space A ′ is between the plurality of vanes 10, 10. The pumping operation described above is performed by sequentially forming them.
[0026]
During the pump operation performed in this way, the space A at the position of FIG. 4 (a) passes through the suction oil passage 20 communicating with the suction port 21 and the space A at the position of FIG. 4 (c). Are communicated with the same type of spaces in the other pump chambers P via pressure chambers 23 communicating with the discharge port 22, and the pressure balance between the two pump chambers P, P is kept good. On the other hand, the confinement space A ′ at the position shown in FIG. 4B is a completely independent space inside the pump chamber P, and the internal pressure of the confinement space A ′ dominates the shape of the pump chamber P. Under the influence of the inner surface shape of the cam ring 2, the cam ring 2 differs depending on the slight difference in the inner surface shape of the cam ring 2 at the corresponding positions of the pump chambers P, P.
[0027]
The communication passage 7 formed as described above communicates with each other the portions to be the confining space A ′ described above in the approximate center positions of the two pump chambers P, P, that is, inside the two pump chambers P, P. In the vane pump according to the present invention having such a communication passage 7, the internal pressure of the confining space A ′ formed in both the pump chambers P and P is equalized via the communication passage 7. Therefore, the pressure balance at each position in the circumferential direction of the rotor 1 can be kept good, and the backlash due to the imbalance of the pressure balance does not occur when the rotor 1 rotates, and the generated sound accompanying this rotation, that is, the vane pump The driving noise can be effectively reduced.
[0028]
FIG. 5 is a graph showing a comparison result of operation sound between the vane pump according to the present invention configured as described above and a conventional vane pump not including the communication passage 7. As shown in this figure, in each operation state performed by changing the discharge pressure variously, the operation sound of the vane pump according to the present invention is significantly lower than the operation sound of the conventional vane pump, The reduction effect of driving noise due to the formation of the passage 7 is obvious.
[0029]
Such an effect of reducing the operating noise is obtained by forming the communication passage 7 that communicates the pump chambers P, P arranged in the circumferential direction of the rotor 1 in the vicinity of the respective central positions. Unlike the vane pump disclosed in Japanese Patent No. 108484, Japanese Patent Laid-Open No. 58-170868, Japanese Patent Laid-Open No. 59-49385, etc., the inner shape of the cam ring 2 is not limited in detail. Can be realized easily.
[0030]
The communication path 7 can be formed in the same manner not only on the mating surface of the cam ring 2 and the pressure plate 3 shown in this embodiment, but also on the mating surface of the cam ring 2 and the end plate 5. The communication path 7 formed in this way opens to the inside of the pump chamber P on the inner peripheral surface of the cam ring 2, but the inner peripheral surface of the cam ring 2 slides on a plurality of vanes 10, 10. As shown in FIG. 6, the open end of the communication path 7 (concave groove 7a) has a size sufficiently smaller than the width of the vane 10 so as not to hinder the sliding contact of the vanes 10. It is desirable to use a squeezed shape.
[0031]
The communication passage 7 can be formed by utilizing the rotor 1 and the boundary surface between the rotor and the pressure plate 3 or the end plate 5. 7 and 8 are explanatory views showing how the communication passage 7 is formed. FIG. 7 is a plan view of the rotor 1 and FIG. 8 is a plan view of the pressure plate 3.
[0032]
The display surface of FIGS. 7 and 8 is the surface facing the other, and as shown by the broken line in FIG. 7, the rotor 1 has an outer peripheral surface between each of the plurality of vanes 10, 10. A vertical hole 7b, 7b,... Has an opening in the substantially central portion in the width direction and is radially inward, and is continuous to the tip of each vertical hole 7b, 7b, and penetrates the rotor 1 in the width direction. Holes 7c, 7c,... Are formed, and these lateral holes 7c, 7c,... Have a predetermined diameter centered on the axis of the rotor shaft 6 at the end surface of the rotor 1 that faces the pressure plate 3. It is arranged side by side with an opening on the circumference of C.
[0033]
On the other hand, as shown in FIG. 8, the end surface of the pressure plate 3 has one end at two locations which are evenly distributed on the circumference of a circle C ′ corresponding to the parallel circle C of the horizontal holes 7c, 7c. Short vertical grooves 7d, 7d that are arranged and extend outward in the radial direction, and an annular groove 7e that connects these outer ends are formed. The positions of the longitudinal grooves 7d and 7d are substantially at the center positions of the pump chambers P and P inside the cam ring 2, as is clear from the comparison with the inner peripheral shape of the cam ring 2 indicated by a two-dot chain line in FIG. It corresponds.
[0034]
Thus, in the vane pump in which the rotor 1 shown in FIG. 7 and the pressure plate 3 shown in FIG. 8 are assembled as shown in FIG. 1, when the rotor 1 rotates, the horizontal holes 7c formed in the rotor 1 are formed. , 7c,..., 7c... Are aligned with the ends of the vertical grooves 7d, 7d of the pressure plate 3 in order, and are continuous with the horizontal holes 7c, 7c. A communication path 7 is formed which communicates the opening positions of 7b and 7b via the vertical grooves 7d and 7d and the annular groove 7e.
[0035]
As described above, the formation positions of the vertical grooves 7d and 7d correspond to the substantially central position of the pump chambers P and P. Therefore, the communication passages 7 that are sequentially formed with the rotation of the rotor 1 are formed at that time. The substantially center of P and P, that is, the confined space A ′ is communicated with each other. The communication path 7 configured as described above requires machining for forming the vertical holes 7b, 7b... And the horizontal holes 7c, 7c. Since the opening end is on the rotor 1 side and there is no opening on the inner peripheral surface of the cam ring 2 which is the sliding contact surface of the vanes 10, 10,..., As shown in FIG. No countermeasure is required, and a reliable communication state can be obtained.
[0036]
In addition, although the present Example described the application example to the vane pump provided with the two pump chambers P and P in the circumferential direction of the rotor 1 and the cam ring 2, application of this invention is applicable also to the structure provided with three or more pump chambers. Further, the present invention is not limited to a vane pump used as a hydraulic pressure generation source of a hydraulic operation device of an automobile, and can be applied to a vane pump for boosting various fluids, and it goes without saying that the same effects can be obtained.
[0037]
【The invention's effect】
As described in detail above, in the vane pump according to the present invention, a plurality of pump chambers between the cam ring and the rotor are formed with communication passages that communicate with each other at circumferential positions that should be confined spaces between adjacent vanes. Since the internal pressure imbalance in the confined space has been eliminated, the generation of driving noise can be effectively reduced with a simple configuration that can be realized regardless of the miniaturization, and quiet operation at high speed is possible. Thus, the present invention has excellent effects.
[Brief description of the drawings]
FIG. 1 is a side sectional view showing an overall configuration of a vane pump according to the present invention.
2 is a cross-sectional view taken along the line II-II in FIG.
FIG. 3 is an enlarged cross-sectional view showing a form of forming a communication path.
FIG. 4 is a plan development view of a pump chamber for explaining a pump operation.
FIG. 5 is a diagram illustrating an operation noise reduction effect by the vane pump according to the present invention.
FIG. 6 is an enlarged view of the vicinity of the open end of the communication path into the pump chamber.
FIG. 7 is a plan view of a rotor for explaining another formation mode of the communication path.
FIG. 8 is a plan view of a pressure plate for explaining another embodiment of the communication path.
[Explanation of symbols]
1 Rotor 2 Cam ring 3 Pressure plate 4 Housing 5 End plate 7 Communication path
7a Groove
7b Vertical hole
7c Horizontal hole
7d vertical groove
7e annular groove
10 Vane
21 Suction port
22 Discharge port P Pump room

Claims (1)

A short cylindrical rotor equipped with a plurality of vanes arranged substantially equally in the circumferential direction so as to be able to advance and retreat in the radial direction is arranged inside the cam ring that forms an uneven ring shape, and a plurality of pumps are mounted on the fitting circumference of both In the vane pump that forms a chamber, confines the fluid sucked into each pump chamber from one side in the circumferential direction between adjacent vanes, rotates by rotating the rotor, pressurizes, and discharges from the other side of each pump chamber, A vane pump comprising: a communication passage that communicates the plurality of pump chambers with each other at a circumferential position to be a fluid confinement space between the vanes.

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