JP5412341B2 - Vane pump - Google Patents

Description

  The present invention relates to a vane pump.

  Conventionally, variable capacity vane pumps have been known in which vanes are retractably accommodated in the slit grooves of the rotor and the volume of the pump chamber formed between the cam ring inner peripheral surface, the rotor outer peripheral surface and the vanes is changed by the cam ring swing. It has been. For example, in the vane pump described in Patent Document 1, when the tip of the vane is located in either the discharge region or the suction region of the pump, substantially the same pressure (back pressure) as the vane tip is applied to the base end of the vane. Make it work. As a result, the resistance when the vane tip slides on the cam ring inner peripheral surface is reduced, and the loss of power for driving the pump is reduced. Further, the discharge side pressure (high pressure) is applied to the base end portion of the vane from before the transition to the discharge region in the suction region of the pump. As a result, even when the working fluid has a high viscosity, the vane is ejected from the slit to suppress the deterioration of the sealing performance of the pump chamber, thereby improving the pump operability.

JP-A-7-259754

  However, the vane pump described in Patent Document 1 has a problem that noise is generated. An object of the present invention is to provide a vane pump capable of reducing noise.

In order to achieve the above object, the vane pump according to the first aspect of the present invention supplies the working oil leaked from the control valve to the suction side back pressure port so that the pressure of the working oil in the suction side back pressure port is lower than the atmospheric pressure. The pressure of the hydraulic oil in the pump chamber in the suction area was made higher.
In the vane pump according to the second aspect of the invention, the ratio of the flow rate of the working oil flowing into the suction port to the first opening area where the working oil flows into the suction port is the suction back with respect to the second opening area where the working oil flows into the suction side back pressure port. The flow rate of the hydraulic oil flowing into the pressure port was made larger than the ratio.

  Therefore, noise can be reduced.

It is a block diagram of CVT to which the vane pump of Example 1 is applied. It is sectional drawing which looked at the inside of the vane pump of Example 1 from the rotating shaft direction. It is the top view which looked at the plate of Example 1 from the z-axis positive direction side. It is the figure which looked at the rear body of Example 1 from the z-axis positive direction side. It is the figure which looked at the front body of Example 1 from the z-axis negative direction side. FIG. 6 is a cross-sectional view taken along the line II in FIG. 5 of the first embodiment. 1 is a schematic diagram of a hydraulic circuit according to a first embodiment.

[Example 1]
[Outline of vane pump]
The outline | summary of the vane pump 1 of Example 1 is demonstrated. The vane pump 1 is used as a hydraulic pressure supply source to a hydraulic actuator of an automobile. Specifically, it is used as a hydraulic pressure supply source for a belt-type continuously variable transmission (CVT100). In addition, you may use as another hydraulic actuator, for example, a hydraulic pressure supply source of a power steering system.
The vane pump 1 is driven by a crankshaft of an internal combustion engine, and sucks and discharges a working fluid. As the working fluid, working oil, specifically ATF (automatic transmission fluid) is used. The hydraulic oil (ATF) has a property that the elastic modulus is relatively small and the pressure greatly changes with a slight volume change.
FIG. 1 is a block diagram illustrating an example of a CVT 100 to which the vane pump 1 is applied.
In the control valve 200, various valves 201 to 213 controlled by the CVT control unit 300 are provided. The hydraulic oil discharged from the vane pump 1 is supplied to each part of the CVT 100 (primary pulley 101, secondary pulley 102, forward clutch 103, reverse brake 104, torque converter 105, lubrication / cooling system 106, etc.) via the control valve 200. Is done.
The vane pump 1 is a variable displacement type that can vary the discharge capacity (the amount of fluid discharged per revolution; hereinafter referred to as the pump capacity), and controls the pump section 2 that sucks and discharges hydraulic oil and the discharge capacity. The controller 3 is provided as an integral unit.

[Configuration of pump section]
The pump unit 2 protrudes and protrudes into a drive shaft 5 driven by a crankshaft, a rotor 6 driven to rotate by the drive shaft 5, and a plurality of slits 61 formed on the outer periphery of the rotor 6 as main components. A vane 7 that can be accommodated, a cam ring 8 that is disposed around the rotor 6, an adapter ring 9 that is disposed around the cam ring 8, a cam ring 8 and an axial side surface of the rotor 6, A plate 41 that forms a plurality of pump chambers r together with the rotor 6 and the vane 7, and a through hole 400, the plate 41 is accommodated in the bottom 402 of the through hole 400, and the cam ring 8, the rotor 6, The rear body 40 that accommodates the vane 7 and the through-hole 400 of the rear body 40 are closed, and a plurality of the cam ring 8, the rotor 6, and the vane 7 are used together. And a front body 42 which forms the pump chamber r.
FIG. 2 is a partial cross-sectional view of the inside of the vane pump 1 as viewed from the direction of the rotation axis. For convenience of explanation, a three-dimensional orthogonal coordinate system is provided, and the x-axis and y-axis are set in the radial direction of the vane pump 1, and the z-axis is set in the rotation axis direction of the vane pump 1. A z-axis is provided on the rotation axis O of the vane pump 1, an x-axis is provided in a direction in which the central axis P of the cam ring 8 swings with respect to the rotation axis O, and a y-axis is provided in a direction orthogonal to the x-axis and the z-axis. . The upper side of the drawing in FIG. 2 is the positive z-axis direction, and the side away from P with respect to O (the first confinement region side with respect to the second confinement region; see FIG. 3) is the x-axis positive direction. On the other hand, the discharge region side is the positive y-axis direction.

(Adapter ring configuration)
The rear body 40 is formed with a substantially cylindrical through hole 400 extending in the z-axis direction. An annular adapter ring 9 is installed in the through hole 400.
The inner peripheral surface of the adapter ring 9 constitutes a substantially cylindrical accommodation hole 90 extending in the z-axis direction. A first plane portion 91 substantially parallel to the yz plane is formed on the x-axis positive direction side of the accommodation hole 90. A second flat surface portion 92 substantially parallel to the yz plane is formed on the x-axis negative direction side of the accommodation hole 90. A step portion 920 is formed on the x-axis negative direction side substantially at the center of the second plane portion 92 in the z-axis direction.
A third plane portion 93 substantially parallel to the z-axis is formed on the positive side of the housing hole 90 in the positive direction of the y-axis and slightly toward the positive direction of the x-axis with respect to the rotation axis O. The third plane portion 93 is formed with a semicircular groove (recess 930) when viewed from the z-axis direction. Communication paths 931 and 932 penetrating the adapter ring 9 in the radial direction are formed on both sides of the recess 930. A first communication path 931 is opened in the third plane part 93 on the x-axis positive direction side of the recess 930, and a second communication path 932 is opened adjacent to the x-axis negative direction side of the third plane part 93. . A fourth plane portion 94 that is substantially parallel to the xz plane is formed on the negative side of the accommodation hole 90 in the y-axis direction. The fourth flat surface portion 94 is formed with a rectangular groove (concave portion 940) when viewed from the z-axis direction.

(Composition of cam ring)
An annular cam ring 8 is swingably installed in the accommodation hole 90 of the adapter ring 9. In other words, the adapter ring 9 is disposed so as to surround the cam ring 8. When viewed from the z-axis direction, the cam ring inner peripheral surface 80 and the cam ring outer peripheral surface 81 of the cam ring 8 are substantially circular, and the radial width of the cam ring 8 is substantially constant. A semicircular groove (concave portion 810) is formed in the cam ring outer peripheral surface 81 on the positive side of the y-axis of the cam ring 8 when viewed from the z-axis direction.
A substantially cylindrical concave portion 811 having an axis in the x-axis direction is formed in the cam ring outer peripheral surface 81 on the x-axis negative direction side of the cam ring 8 to a predetermined depth. Between the concave portion 930 on the inner periphery of the adapter ring and the concave portion 810 on the outer periphery of the cam ring, the pin 10 extending in the z-axis direction is disposed in contact with the concave portions 930 and 810 so as to be sandwiched between the concave portions 930 and 810.
The seal member 11 is installed in the recess 940 on the inner periphery of the adapter ring. The seal member 11 is in contact with the y-axis negative direction side of the cam ring outer peripheral surface 81.
One end of a spring 12 as an elastic member is installed on the step portion 920 on the inner periphery of the adapter ring. The spring 12 is a coil spring. The other end of the spring 12 is fitted into the recess 811 on the outer periphery of the cam ring. The spring 12 is installed in a compressed state, and constantly biases the cam ring 8 toward the x-axis positive direction side with respect to the adapter ring 9.
The dimension of the accommodation hole 90 of the adapter ring 9 in the x-axis direction, that is, the distance between the first flat surface portion 91 and the second flat surface portion 92 is set larger than the diameter of the cam ring outer peripheral surface 81. The cam ring 8 is supported by the flat portion 93 with respect to the adapter ring 9 and is installed so as to be swingable within the xy plane with the flat portion 93 as a fulcrum. The pin 10 suppresses displacement (relative rotation) of the cam ring 8 with respect to the adapter ring 9.
The swing of the cam ring 8 is restricted by the cam ring outer peripheral surface 81 coming into contact with the first flat surface portion 91 of the adapter ring 9 on the x-axis positive direction side, and the cam ring outer peripheral surface 81 on the x-axis negative direction side. 9 is regulated by coming into contact with the second flat surface portion 92. Let δ be the amount of eccentricity of the central axis P of the cam ring 8 with respect to the rotational axis O. At the position (minimum eccentric position) where the cam ring outer peripheral surface 81 abuts against the second flat surface portion 92, the eccentric amount δ becomes the minimum value. At the position (maximum eccentric position) in FIG. 2 where the cam ring outer peripheral surface 81 contacts the first flat surface portion 91, the amount of eccentricity δ is maximized. When the cam ring 8 swings, the flat portion 93 comes into sliding contact with the cam ring outer peripheral surface 81 and the seal member 11 comes into sliding contact with the cam ring outer peripheral surface 81.

(Control room configuration)
The space between the adapter ring inner peripheral surface 95 and the cam ring outer peripheral surface 81 is sealed by the plate 41 on the z-axis negative direction side and the front body 42 on the z-axis positive direction side, while the flat portion 93 and the seal member 11 are sealed. Thus, the two control chambers R1 and R2 are liquid-tightly separated.
A first control chamber R1 is formed on the x-axis positive direction side, and a second control chamber R2 is formed on the x-axis negative direction side. A first communication passage 931 is opened in the first control chamber R1, and a second communication passage 932 is opened in the second control chamber R2. Note that a predetermined gap is ensured between the outer periphery of the cam ring and the inner periphery of the adapter ring at the restriction position, and the volumes of the first and second control chambers R1 and R2 are not less than a predetermined value and do not become zero.

(Configuration of rotor)
A drive shaft 5 is rotatably supported on the body 4 (rear body 40, plate 41, front body 42). The drive shaft 5 is coupled to the crankshaft of the internal combustion engine via a chain, and rotates in synchronization with the crankshaft. On the outer periphery of the drive shaft 5, a rotor 6 is fixed coaxially (spline coupling). The rotor 6 has a substantially cylindrical shape and is installed on the inner peripheral side of the cam ring 8. In other words, the cam ring 8 is disposed so as to surround the rotor 6. An annular chamber R3 is formed between the rotor outer peripheral surface 60 of the rotor 6, the cam ring inner peripheral surface 80 of the cam ring 8, the plate 41, and the front body 42. The rotor 6 rotates together with the drive shaft 5 around the rotation axis O in the clockwise direction of FIG.
The rotor 6 has a plurality of grooves (slits 61) formed radially. Each slit 61 is provided in a straight line extending in the rotor radial direction from the rotor outer peripheral surface 60 toward the rotation axis O to a predetermined depth when viewed from the z-axis direction, and covers the entire range of the rotor 6 in the z-axis direction. Is formed. The slit 61 is formed at eleven locations at positions where the rotor 6 is equally divided in the circumferential direction.
The vane 7 is a substantially rectangular plate member (blade), and a plurality (11) of vanes 7 are provided, and each vane 7 is housed in each slit 61 so as to be able to appear and disappear. The tip end portion (vane tip portion 70) of the vane 7 on the rotor outer diameter side (the side away from the rotation axis O) is formed in a gently curved shape corresponding to the cam ring inner peripheral surface 80. The number of slits 61 and vanes 7 is not limited to 11.
The end portion (slit base end portion 610) of each slit 61 on the rotor inner diameter side (side toward the rotation axis O) is formed in a substantially cylindrical shape, and the slit main body portion in the rotor circumferential direction when viewed from the z-axis direction. It is a substantially circular shape with a diameter larger than the width of 611. Note that the slit base end portion 610 does not have to be formed in a cylindrical shape, and may have a groove shape similar to that of the slit main body portion 611, for example. A back pressure chamber br (pressure receiving portion) of the vane 7 is formed between the slit base end portion 610 and the end portion (vane base end portion 71) of the vane 7 accommodated in the slit 61 on the rotor inner diameter side. Has been.

The rotor outer peripheral surface 60 is provided with a substantially trapezoidal protrusion 62 at a position corresponding to each vane 7 when viewed from the z-axis direction. The protrusion 62 is formed to protrude from the rotor outer peripheral surface 60 to a predetermined height over the entire range of the rotor 6 in the z-axis direction. An opening of each slit 61 is provided at a substantially central position of the protrusion 62. The length of the slit 61 in the rotor radial direction (including the protruding portion 62 and the slit base end portion 610) is substantially the same as the length of the vane 7 in the rotor radial direction.
By providing the projecting portion 62, the length in the rotor radial direction of the slit 61 is secured to a predetermined value or more. For example, even if the vane 7 protrudes from the slit 61 to the maximum in the first confinement region, It is secured. In other words, since the protrusions 62 improve the retainability of the vanes 7 and the meat other than the protrusions 62 is removed from the rotor outer peripheral surface 60, the volume of the pump chamber r is increased by this thinning to increase the pump efficiency. The weight of the entire rotor 6 is reduced and power loss is reduced.
The annular chamber R3 is partitioned into a plurality (11) of pump chambers (volume chambers) r by a plurality of vanes 7. Hereinafter, the distance between adjacent vanes 7 (between the side surfaces of the two vanes 7) in the rotation direction of the rotor 6 (clockwise direction in FIG. 2, hereinafter simply referred to as the rotation direction) is referred to as one pitch. The width in the rotation direction of one pump chamber r is one pitch and is unchanged.
In a state where the central axis P of the cam ring 8 is decentered with respect to the rotation axis O (toward the x-axis positive direction), the rotor outer peripheral surface 60 and the cam ring inner peripheral surface move from the x-axis negative direction side toward the x-axis positive direction side. The rotor radial distance from 80 (the radial dimension of the pump chamber r) increases. In response to this change in distance, the vanes 7 appear and disappear from the slits 61 to separate the pump chambers r, and the pump chamber r on the x-axis positive direction side has a pump chamber r on the x-axis negative direction side. Rather than the volume. Due to the difference in volume of the pump chamber r, on the y-axis negative direction side with respect to the x-axis, as the pump chamber r moves toward the x-axis positive direction side which is the rotational direction of the rotor 6 (clockwise direction in FIG. 2), While the volume increases, on the y-axis positive direction side with respect to the x-axis, the volume of the pump chamber r decreases toward the negative x-axis direction that is the rotation direction of the rotor 6 (clockwise direction in FIG. 2). .

[Plate configuration]
FIG. 3 is a plan view of the plate 41 as viewed from the z-axis positive direction side. The plate 41 is formed with a suction port 43, a discharge port 44, a suction side back pressure port 45, a discharge side back pressure port 46, a pin installation hole 47, and a through hole 48. The pin 10 is inserted and fixedly installed in the pin installation hole 47. The drive shaft 5 is inserted into the through hole 48 and is rotatably installed.

(Configuration of suction port)
The suction port 43 is a portion that serves as an inlet for introducing hydraulic oil from the outside into the suction-side pump chamber r, and is a section on the y-axis negative direction side in which the volume of the pump chamber r increases in accordance with the rotation of the rotor 6. Is provided. The suction port 43 has a suction-side arc groove 430, a suction hole 431, and a communication hole 432. The suction-side arc groove 430 is formed in the surface 410 on the positive side of the z-axis of the plate 41 and is a groove into which the pump suction-side hydraulic pressure is introduced. The suction-side arc groove 430 rotates along the arrangement of the suction-side pump chamber r. It is formed in a substantially arc shape centered on O.
An angular range corresponding to the suction side arc groove 430, that is, approximately 4.5 pitches formed by the start point A on the negative side of the x axis and the end point B on the positive side of the x axis of the suction side arc groove 430 with respect to the rotation axis O. The suction region of the vane pump 1 is provided in the range of the angle α corresponding to. The start point A and the end point B of the suction-side arc groove 430 are provided at positions separated from the x-axis by an angle β corresponding to approximately 0.5 pitch on the y-axis negative direction side.
The end portion 436 of the suction side arc groove 430 is formed in a substantially semicircular arc shape convex in the rotation direction. The starting end 435 of the suction-side arc groove 430 is formed with a main body starting end 433 formed in a substantially semicircular arc shape convex in the negative rotation direction, and a notch 434 continuous with the main body starting end 433. The notch 434 is formed with a length of approximately 0.5 pitch so as to extend from the main body start end 433 in the pump rotation direction and the rotation negative direction, and the tip thereof coincides with the start point A. The rotor radial width of the suction-side arc groove 430 is substantially equal in the entire rotational direction, and is substantially equal to the rotor radial width of the annular chamber R3 when the cam ring 8 is at the minimum eccentric position (see FIG. 2). .
An edge 437 on the rotor inner diameter side of the suction-side arc groove 430 is located slightly on the rotor outer diameter side with respect to the rotor outer peripheral surface 60 (excluding the protruding portion 62). The edge 438 on the rotor outer diameter side of the suction side arc groove 430 is located slightly on the outer diameter side of the rotor from the cam ring inner peripheral surface 80 of the cam ring 8 at the minimum eccentric position, and the cam ring at the maximum eccentric position on the terminal side thereof. 8 is located slightly on the outer diameter side of the rotor from the inner peripheral surface 80 of the cam ring. Regardless of the eccentric position of the cam ring 8, each suction-side pump chamber r overlaps with the suction-side arc groove 430 when viewed from the z-axis direction and communicates with the suction-side arc groove 430.

A suction hole 431 is opened substantially at the center in the rotation direction of the suction side arc groove 430. The suction hole 431 is substantially oval when viewed from the z-axis direction, has a rotor radial width that is substantially equal to the suction-side arc groove 430, and a length in the rotational direction of approximately one pitch. The suction hole 431 is formed at a position that penetrates the plate 41 in the z-axis direction and overlaps the y-axis.
In the suction-side arc groove 430, a communication hole 432 is opened adjacent to the suction hole 431 and closer to the negative rotation direction (starting point A side). The communication hole 432 has the same shape as the suction hole 431 and penetrates the plate 41 in the z-axis direction. The suction-side arc groove 430 has a depth (z-axis direction) that is less than 20% of the thickness of the plate 41 (z-axis direction) at the main body start end 433, between the communication hole 432 and the suction hole 431, and at the end 436. Have
A slope is provided between the main body start end 433 and the communication hole 432, and is formed so as to be gradually deeper in the rotation direction and to have the same depth as the thickness of the plate 41 at a portion reaching the communication hole 432. . A slope is provided between the suction hole 431 and the end portion 436, and is formed so as to become gradually shallower in the rotation direction and to have the same depth as the main body start end portion 433 at a portion reaching the end portion 436.
The notch 434 is provided in a substantially acute triangular shape in which the width in the rotor radial direction gradually increases in the rotational direction as viewed from the z-axis direction. The maximum value of the rotor radial width of the notch 434 is set smaller than the width of the suction-side arc groove 430. The depth of the notch 434 (in the z-axis direction) gradually increases from zero to several percent of the thickness of the plate 41 in the rotational direction. That is, the channel cross-sectional area of the notch 434 is smaller than the main body portion of the suction-side arc groove 430, and the notch 434 constitutes a throttle portion where the channel cross-sectional area gradually increases in the rotation direction.

(Configuration of discharge port)
The discharge port 44 is a portion serving as an outlet when the hydraulic oil is discharged from the pump chamber r on the discharge side to the outside, and a section on the y-axis positive direction side in which the volume of the pump chamber r is reduced according to the rotation of the rotor 6. Is provided. The discharge port 44 includes a discharge-side arc groove 440, a communication hole 441, and discharge holes 441 and 442. The discharge-side arc groove 440 is formed in the surface 410 of the first plate 41, and is a groove into which the pump discharge-side hydraulic pressure is introduced. The discharge-side arc groove 440 is centered on the rotation axis O along the arrangement of the discharge-side pump chamber r. It is formed in a substantially arc shape.
An angle range corresponding to the discharge-side arc groove 440, that is, a range of an angle α formed by the start point C on the positive x-axis side and the end point D on the negative x-axis side of the discharge-side arc groove 440 with respect to the rotation axis O. A discharge region of the vane pump 1 is provided. The start point C and the end point D of the discharge-side arc groove 440 are provided at positions separated from the x-axis by an angle β corresponding to approximately 0.5 pitches on the y-axis positive direction side.
The rotor radial width of the discharge-side arc groove 440 is substantially equal in the entire rotation direction, and is slightly smaller than the rotor radial width of the suction-side arc groove 430. An edge 446 on the rotor inner diameter side of the discharge-side arc groove 440 is located slightly on the rotor outer diameter side with respect to the rotor outer peripheral surface 60 (excluding the protruding portion 62). An edge 447 on the rotor outer diameter side of the discharge-side arc groove 440 substantially overlaps the cam ring inner peripheral surface 80 of the cam ring 8 at the minimum eccentric position. Regardless of the eccentric position of the cam ring 8, each discharge-side pump chamber r overlaps with the discharge-side arc groove 440 and communicates with the discharge-side arc groove 440 when viewed from the z-axis direction.
A discharge hole 442 is opened at the end portion 444 of the discharge-side arc groove 440 on the rotation direction side. The discharge holes 442 are substantially oval when viewed from the z-axis direction, the width in the rotor radial direction is substantially equal to the discharge-side arc groove 440, and the length in the rotation direction is slightly longer than approximately 1 pitch. The discharge hole 442 is formed through the plate 41 in the z-axis direction. The rotation direction side edge of the discharge hole 442 is formed in a substantially semicircular arc shape convex in the rotation direction, and coincides with the rotation direction side edge of the terminal portion 444.

A communication hole 441 is opened at a position facing the suction side communication hole 432 across the rotation axis O at a position closer to the negative rotation direction of the discharge side arc groove 440. The communication holes 441 have the same shape as the discharge holes 442, have a length in the rotation direction of approximately one pitch, and are formed through the plate 41 in the z-axis direction. The start end 443 of the discharge-side arc groove 440 is formed to extend from the start point C to the edge 445 on the rotation negative direction side of the communication hole 441. The edge 445 is formed in a substantially semicircular arc shape convex in the negative rotation direction when viewed from the z-axis direction, and its tip E is located at a distance of about one pitch from the start point C in the rotation direction. The tip of the start end 443 that faces the end point B of the suction-side arc groove 430 in the rotational direction is formed in a substantially rectangular shape when viewed from the z-axis direction, and has an edge that extends in the rotor radial direction.
The depth (in the z-axis direction) of the main body portion 448 provided between the communication hole 441 and the discharge hole 442 of the discharge-side arc groove 440 is approximately 25% of the thickness of the plate 41 (in the z-axis direction). The starting end 443 has a groove depth shallower than that of the main body 448, and is inclined from the starting point C to the edge 445. The groove depth at the starting point C is 0, and gradually becomes deeper toward the edge 445, and at the portion reaching the edge 445, the depth is less than 10% of the thickness of the first plate 41.
The start end 443 is provided with a shape in which the flow path cross-sectional area is smaller than that of the main body 448 and the depth gradually increases (in the z-axis direction) in the rotation direction. This constitutes a throttle portion where gradually increases. The surface 410 between the end point B of the suction side arc groove 430 and the start point C of the discharge side arc groove 440 is not provided with a groove, and the end point B with respect to the angular range corresponding to this section, that is, the rotation axis O. The first confinement region of the vane pump 1 is provided in the range of the angle 2β formed by the start point C. The angle range of the first confinement region corresponds to approximately one pitch.
Similarly, the surface 410 between the end point D of the discharge-side arc groove 440 and the start point A of the suction-side arc groove 430 is not provided with a groove, and an angular range corresponding to this section, that is, with respect to the rotation axis O. Thus, a second confinement region is provided in the range of the angle 2β formed by the end point D and the start point A. The angle range of the second confinement region corresponds to approximately one pitch.

(Containment area)
The first confinement region and the second confinement region are portions that contain the hydraulic oil in the pump chamber r in this region and prevent the discharge-side arc groove 440 and the suction-side arc groove 430 from communicating with each other. It is provided in a section straddling the x axis (see FIG. 3).
(Back pressure port)
The plate 41 is provided with back pressure ports 45 and 46 communicating with the base of the vane 7 (back pressure chamber br, slit base end 610) separately on the suction side and the discharge side (see FIG. 3). ).

<Suction-side back pressure port> (See Fig. 3)
The suction-side back pressure port 45 is a port that communicates the suction ports 43 with the back pressure chambers br of the plurality of vanes 7 located in most of the suction region. The phrase “the vane 7 is located in the suction region” means that the vane tip portion 70 of the vane 7 overlaps the suction port 43 (suction side arc groove 430) when viewed from the z-axis direction. The suction side back pressure port 45 has a suction side back pressure arc groove 450 and a communication hole 451.
The suction-side back pressure arc groove 450 is formed on the surface 410 of the plate 41, and is a groove into which the pump suction-side hydraulic pressure is introduced. The suction-side back pressure arc groove 450 is formed in the back pressure chamber br of the vane 7 (the slit base end 610 of the rotor 6). Along the arrangement, it is formed in a substantially arc shape with the rotation axis O as the center. The suction side back pressure arc groove 450 is formed in an angle range corresponding to approximately three pitches (a range narrower than the suction side arc groove 430).
The starting point a of the suction side back pressure arc groove 450 is slightly on the rotational direction side of the suction side arc groove 430 (notch 434) and is adjacent to the rotational direction side of the main body start end 433. The end point b of the suction-side back pressure arc groove 450 is located at a position away from the end point B of the suction-side arc groove 430 by an angle corresponding to approximately 1.5 pitches on the rotation negative direction side. The rotor radial dimension (groove width) of the suction-side back pressure arc groove 450 is substantially the same in the entire rotational direction, is substantially equal to the suction-side arc groove 430, and is the same as the rotor radial dimension of the slit base end 610. Almost equal.
The edge 454 on the rotor inner diameter side of the suction side back pressure arc groove 450 is located slightly on the rotor inner diameter side with respect to the rotor inner diameter side edge of the slit base end portion 610. An edge 455 on the rotor outer diameter side of the suction side back pressure arc groove 450 is positioned slightly closer to the rotor inner diameter side than the rotor outer diameter side edge of the slit base end 610. Regardless of the eccentric position of the cam ring 8, when viewed from the z-axis direction, the suction-side back pressure arc groove 450 is provided at a position in the rotor radial direction that substantially overlaps the slit base end portion 610 (back pressure chamber br). When it overlaps with the slit base end portion 610 (back pressure chamber br), it communicates with this.
A communication hole 451 opens at a position overlapping the communication hole 432 of the suction-side arc groove 430 in the rotor radial direction near the negative rotation direction (starting point a side) of the suction-side back pressure arc groove 450. The communication hole 451 is substantially oval when viewed from the z-axis direction, has a width in the rotor radial direction substantially equal to that of the suction-side back pressure arc groove 450, and a length in the rotation direction of approximately 1 pitch. The communication hole 451 is formed so as to penetrate the plate 41 in the z-axis direction, and communicates with the communication hole 432 of the suction side arc groove 430 through a low pressure chamber 491 of the rear body 40 described later.
In the suction-side back pressure arc groove 450, a start end portion 452 is provided between the start point a and the suction hole 431. When viewed from the z-axis direction, the tip of the starting end portion 452 is formed in a substantially semicircular arc shape that is convex in the negative rotation direction. The end portion 453 of the suction side back pressure arc groove 450 is formed in a substantially semicircular arc shape convex in the rotation direction. The depth of the start end portion 452 (in the z-axis direction) is a little less than 40% of the thickness of the plate 41, and the depth of the end portion 453 is a little less than 20% of the thickness of the plate 41. The section from the end portion 453 to the communication hole 451 is inclined, and gradually becomes deeper toward the communication hole 451 in the negative direction of rotation, and the portion reaching the communication hole 451 has the same depth as the thickness of the plate 41. It is formed as follows.

<Discharge side back pressure port> (See Fig. 3)
The discharge-side back pressure port 46 includes a discharge port, a back pressure chamber br of a plurality of vanes 7 located in most of the discharge region, the first confinement region, the second confinement region, and a part of the suction region, and the discharge port 44. It is a port that communicates. The phrase “the vane 7 is located in the discharge region” means that the vane tip portion 70 of the vane 7 overlaps with the discharge port 44 (discharge-side arc groove 440) and the like when viewed from the z-axis direction. The discharge side back pressure port 46 has a discharge side back pressure arc groove 460 and a communication hole 461.
The discharge-side back pressure arc groove 460 is formed on the surface 410 of the plate 41 and is a groove into which the pump discharge-side hydraulic pressure is introduced, and follows the arrangement of the back pressure chamber br (slit base end 610) of the vane 7. Thus, it is formed in a substantially arc shape with the rotation axis O as the center. The discharge-side back pressure arc groove 460 is formed in an angle range corresponding to approximately seven pitches (a range wider than the discharge-side arc groove 440).
The discharge-side back pressure arc groove 460 is formed so as to face the suction region, and the start point c of the discharge-side back pressure arc groove 460 is first closed closer to the rotation negative direction side than the start point C of the discharge-side arc groove 440. It is located on the rotation negative direction side beyond the end point B of the suction side arc groove 430 beyond the intrusion region. The start point c is located at a distance of approximately 1 pitch (corresponding to 2β) from the end point B.
The end point d of the discharge-side back pressure arc groove 460 is separated from the end point D of the discharge-side arc groove 440 by an angle corresponding to a little less than one pitch in the rotational direction, and is located near the end portion of the second confinement region. ing.
The rotor radial dimension (groove width) of the discharge-side back pressure arc groove 460 is substantially the same in the entire rotation direction, and is slightly smaller than the discharge-side arc groove 440, and the rotor radial direction of the slit base end 610 Slightly smaller than the dimensions.

The rotor inner diameter side edge 464 of the discharge side back pressure arc groove 460 is located slightly on the rotor outer diameter side of the slit inner end side edge 610 of the rotor inner diameter side edge. A rotor outer diameter side edge 465 of the discharge-side back pressure arc groove 460 is positioned slightly closer to the rotor inner diameter side than the rotor outer diameter side edge of the slit base end 610. Regardless of the eccentric position of the cam ring 8, when viewed from the z-axis direction, the discharge-side back pressure arc groove 460 is provided at a position in the rotor radial direction that substantially overlaps the slit base end portion 610 (back pressure chamber br). When it overlaps with the slit base end portion 610 (back pressure chamber br), it communicates with this.
Near the negative rotation direction (starting point c side) of the discharge-side back pressure arc groove 460, the end point B of the suction-side arc groove 430 and the x-axis (the intermediate point of the first closing region) are located at the starting end side of the first closing region. ), A communication hole 461 is opened at an angular position. The diameter of the communication hole 461 is substantially equal to the rotor radial width of the discharge-side back pressure arc groove 460. The communication hole 461 is formed through the plate 41 obliquely with respect to the z-axis direction so as to be positioned on the rotor outer diameter side in the plate 41 toward the z-axis negative direction side. The communication hole 461 opens on the surface on the negative side of the z-axis of the first plate 41 and communicates with the communication hole 441 of the discharge port 44 (discharge-side arc groove 440) via a high-pressure chamber 492 of the rear body 40 described later. Yes. The discharge-side back pressure arc groove 460 has a start end 462 and a back pressure port main body 468.

[Details of control unit]
Referring back to FIG. 2, the control unit 3 is provided in the rear body 40, and includes a control valve 30, first and second passages 31, 32, and control chambers R1, R2.
The control valve 30 is a hydraulic control valve (spool valve), and the first passage 31 formed in the rear body 40, the first passage 31 formed in the rear body 40 by driving the spool 302 accommodated in the accommodation hole 401 in the rear body 40 by the solenoid 301. The supply of hydraulic oil to the two passages 32 is switched. The first passage 31 communicates with the first communication passage 931 to constitute a first control oil passage. The second passage 32 communicates with the second communication passage 932 to constitute a second control oil passage. The operation of the control valve 30 is controlled by the CVT control unit 300 based on, for example, the rotational speed of the internal combustion engine and the throttle valve opening.

[Details of rear body]
FIG. 4 is a view of the rear body 40 as viewed from the z-axis positive direction side. A through hole 490, a low pressure chamber 491, a high pressure chamber 492, and a discharge chamber 493 are formed in the bottom portion 402 of the rear body 40.
The drive shaft 5 is inserted into the through hole 490 and is rotatably installed. The low pressure chamber 491 is formed in a concave shape in the bottom portion 402. The opening of the low pressure chamber 491 is provided so as to cover the opening in the negative z-axis direction of the suction hole 431 of the suction port 43 formed in the plate 41, the communication hole 432, and the communication hole 451 of the suction side back pressure port 45. It has been. That is, the suction port 43 and the suction side back pressure port 45 communicate with each other via the low pressure chamber 491, and suction pressure acts on the suction port 43 and the suction side back pressure port 45.
The high pressure chamber 492 is formed in a concave shape in the bottom portion 402. The opening of the high-pressure chamber 492 is provided so as to cover the communication hole 441 of the discharge port 44 formed in the plate 41 and the z-axis negative direction side opening of the communication hole 461 of the discharge-side back pressure port 46. In other words, the discharge port 44 and the discharge side back pressure port 46 communicate with each other via the high pressure chamber 492, and the discharge pressure acts on the discharge port 44 and the discharge side back pressure port 46.
The discharge chamber 493 is formed in the bottom 402 in a concave shape. The opening of the discharge chamber 493 is provided so as to cover the z-axis negative direction opening of the discharge hole 442 of the discharge port 44 formed in the plate 41. The discharge chamber 493 communicates with the discharge passage 65 (see FIG. 2), and high-pressure hydraulic oil is discharged from the discharge passage 65.
A seal groove 494 is formed so as to cover the outer periphery of the high pressure chamber 492 and the discharge chamber 493. A seal member 495 is provided in the seal groove 494. In a state where the surface of the plate 41 on the negative side in the z-axis is disposed so as to face the bottom 402 of the rear body 40, the seal member 495 is compressed in the z-axis direction and closely contacts the surface of the plate 41 on the negative side in the z-axis. As a result, the high-pressure chamber 492 and the discharge chamber 493 are kept liquid-tight. The seal member 495 defines a low pressure region 496 outside the seal member 495 and a high pressure region 497 inside the seal member 495.

[Details of front body]
FIG. 5 is a view of the front body 42 as seen from the z-axis negative direction side. 6 is a sectional view taken along line II in FIG.
The front body 42 has a plate surface 50 protruding in the z-axis negative direction. The plate surface 50 is formed with a suction port 51, a discharge port 52, a suction side back pressure port 53, a discharge side back pressure port 54, a pin installation hole 55, and a through hole 56. The pin 10 is inserted and fixedly installed in the pin installation hole 55. The drive shaft 5 is inserted into the through hole 56 and is rotatably installed. The suction port 51, the discharge port 52, the suction side back pressure port 53, and the discharge side back pressure port 54 are a suction port 43 formed in the plate 41, a discharge port 44, a suction side back pressure port 45, and a discharge side. It is formed at a position corresponding to the back pressure port 46.
(Configuration of suction port) (See Fig. 5)
The suction port 51 communicates with the suction-side pump chamber r, and is provided in a section on the y-axis negative direction side where the volume of the pump chamber r increases as the rotor 6 rotates. The suction port 51 has a suction-side arc groove 510, a suction hole 511, and a communication hole 512. The suction-side arc groove 510 is formed in a substantially arc shape centering on the rotation axis O along the arrangement of the suction-side pump chamber r.
The end portion 516 of the suction side arc groove 510 is formed in a substantially semicircular arc shape convex in the rotation direction. The starting end 515 of the suction side arc groove 510 is formed in a substantially semicircular arc shape convex in the negative rotation direction. The rotor radial width of the suction-side arc groove 510 is substantially equal in the entire rotational direction range, and is substantially equal to the rotor radial width of the annular chamber R3 when the cam ring 8 is at the minimum eccentric position.
An edge 517 on the rotor inner diameter side of the suction-side arc groove 510 is located slightly on the rotor outer diameter side with respect to the rotor outer peripheral surface 60 (excluding the protruding portion 62). An edge 518 on the rotor outer diameter side of the suction-side arc groove 510 is located slightly on the rotor outer diameter side of the cam ring inner peripheral surface 80 of the cam ring 8 in the minimum eccentric position, and is located on the terminal end side of the cam ring in the maximum eccentric position. 8 is located slightly on the outer diameter side of the rotor from the inner peripheral surface 80 of the cam ring. Regardless of the eccentric position of the cam ring 8, each suction-side pump chamber r overlaps the suction-side arc groove 510 and communicates with the suction-side arc groove 510 when viewed from the z-axis direction.
A suction hole 511 is opened from the end portion in the rotation direction of the suction-side arc groove 510 to the vicinity of the center portion. The suction hole 511 has a rotor radial width that is substantially the same as the suction-side arc groove 510 and a length in the rotational direction of approximately three pitches. The suction hole 511 is connected to a suction passage 64 formed in the front body 42, and hydraulic oil is supplied from the suction passage 64.
In the suction-side arc groove 510, a communication hole 512 is opened adjacent to the suction hole 511 on the end side in the rotation direction. The communication hole 512 has a rotor radial width that is substantially equal to the suction-side arc groove 510 and a length in the rotation direction of approximately one pitch. The communication hole 512 is also connected to a suction passage 64 formed in the front body 42.

(Configuration of discharge port) (See Fig. 5)
The discharge port 52 is provided in a section on the y-axis positive direction side in which the volume of the pump chamber r is reduced according to the rotation of the rotor 6. The discharge port 52 has a discharge-side arc groove 520 having an orifice groove 521. The discharge-side arc groove 520 is formed in a substantially arc shape around the rotation axis O along the arrangement of the discharge-side pump chamber r.
The width of the discharge-side arc groove 520 in the rotor radial direction is substantially the same in the entire rotation direction, and is slightly smaller than the width of the suction-side arc groove 510 in the rotor radial direction. An edge 526 on the rotor inner diameter side of the discharge-side arc groove 520 is located slightly on the rotor outer diameter side with respect to the rotor outer peripheral surface 60 (excluding the protruding portion 62). An edge 527 on the rotor outer diameter side of the discharge-side arc groove 520 substantially overlaps the cam ring inner peripheral surface 80 of the cam ring 8 at the minimum eccentric position. Each discharge-side pump chamber r overlaps with the discharge-side arc groove 520 and communicates with the discharge-side arc groove 520 when viewed from the z-axis direction, regardless of the eccentric position of the cam ring 8.
An orifice groove 521 is formed at the end of the discharge-side arc groove 520 on the rotation negative direction side. The orifice groove 521 is formed to be shallower than the discharge-side arc groove 520.
The end in the rotation positive direction side of the discharge-side arc groove 520 is formed in a substantially semicircular shape that is convex toward the rotation positive direction. The discharge arcuate groove 520 is on the side of the negative rotation direction, and the boundary with the orifice groove 521 is formed in a substantially semicircular shape convex toward the negative rotation direction. Further, the edge on the rotation negative direction side of the orifice groove 521 is formed in a rectangular shape.

(Configuration of suction side back pressure port) (See Fig. 5)
On the plate surface 51, back pressure ports 53 and 54 communicating with the root of the vane 7 (back pressure chamber br, slit base end 610) are provided separately on the suction side and the discharge side, respectively. The suction-side back pressure port 53 is a port that communicates the back pressure chambers br of the plurality of vanes 7 located in most of the suction region and the suction port 51. The suction side back pressure port 53 has a suction side back pressure arc groove 530 and a communication hole 531.
The suction-side back pressure arc groove 530 is formed in a substantially arc shape centering on the rotation axis O along the arrangement of the back pressure chamber br (slit base end portion 610 of the rotor 6) of the vane 7. The suction-side back pressure arc groove 530 is formed in an angle range corresponding to approximately three pitches (a range narrower than the suction-side arc groove 510).
The rotor radial dimension (groove width) of the suction-side back pressure arc groove 530 is substantially the same in the entire rotation direction, is substantially equal to the suction-side arc groove 510, and the rotor radial dimension of the slit base end 610 Almost equal.
An edge 534 on the rotor inner diameter side of the suction side back pressure arc groove 530 is positioned slightly closer to the rotor inner diameter side than the rotor inner diameter side edge of the slit base end portion 610. The rotor outer diameter side edge 515 of the suction side back pressure arc groove 530 is positioned slightly closer to the rotor inner diameter side than the rotor outer diameter side edge of the slit base end 610. Regardless of the eccentric position of the cam ring 8, when viewed from the z-axis direction, the suction-side back pressure arc groove 530 is provided at a position in the rotor radial direction that substantially overlaps the slit base end portion 610 (back pressure chamber br). When it overlaps with the slit base end portion 610 (back pressure chamber br), it communicates with this.
Near the negative rotation direction of the suction side back pressure arc groove 530, a communication hole 531 opens at a position overlapping the communication hole 512 of the suction side arc groove 510 in the rotor radial direction. The communication hole 531 is substantially oval when viewed from the z-axis direction, has a width in the rotor radial direction substantially equal to that of the suction-side back pressure arc groove 530, and a length in the rotation direction of about 1 pitch.
When viewed from the z-axis direction, both sides of the suction-side back pressure arc groove 530 in the rotational direction are formed in a substantially semicircular arc shape convex in the rotational direction.

(Configuration of discharge-side back pressure port) (See Fig. 5)
The discharge side back pressure port 54 includes a discharge side back pressure arc groove 540 and an orifice groove 541.
The discharge-side back pressure arc groove 540 is formed in a substantially arc shape around the rotation axis O along the arrangement of the back pressure chamber br (slit base end 610) of the vane 7. The discharge-side back pressure arc groove 540 is formed in an angle range corresponding to approximately seven pitches (a range wider than the discharge-side arc groove 520).
The discharge-side back pressure arc groove 540 is formed so as to face the suction area, and the start point of the discharge-side back pressure arc groove 540 is closer to the negative rotation direction side than the start point of the discharge-side arc groove 520, and the first confinement area. And is further on the negative rotation direction side than the end point of the suction-side arc groove 510.
The end point of the discharge-side back pressure arc groove 540 is formed to the rotational direction side from the end point of the discharge-side arc groove 520, and is located near the end portion of the second confinement region.
The rotor radial dimension (groove width) of the discharge-side back pressure arc groove 540 is substantially the same in the entire rotational direction, and is slightly smaller than the discharge-side arc groove 520, and the rotor radial direction of the slit base end 610 Slightly smaller than the dimensions.
An edge 544 on the rotor inner diameter side of the discharge-side back pressure arc groove 540 is located slightly on the rotor outer diameter side of the rotor inner diameter side edge of the slit base end 610. An edge 545 on the rotor outer diameter side of the discharge-side back pressure arc groove 540 is positioned slightly closer to the rotor inner diameter side than the rotor outer diameter side edge of the slit base end 610. Regardless of the eccentric position of the cam ring 8, when viewed from the z-axis direction, the discharge-side back pressure arc groove 540 is provided at a position in the rotor radial direction that substantially overlaps the slit base end portion 610 (back pressure chamber br). When it overlaps with the slit base end portion 610 (back pressure chamber br), it communicates with this.
The end part on the rotation positive direction side of the discharge-side back pressure arc groove 540 is formed in a substantially semicircular shape convex toward the rotation positive direction. Further, the boundary portion between the discharge side back pressure arc groove 540 and the orifice groove 521 is formed in a rectangular shape. Further, the edge on the rotation negative direction side of the orifice groove 541 is formed in a rectangular shape.

(Lubricating oil groove) (See Fig. 5)
At the end of the discharge side arc groove 520 of the discharge port 52 in the positive rotation direction, a lubricating oil groove 57 that is a second confinement region and communicates with the outer peripheral side of the suction port 51 and the discharge port 52 is formed. In addition, a lubricating oil groove 58 that is a first confinement region and communicates with the outer peripheral side of the suction port 51 and the discharge port 52 is formed on the positive rotation direction side of the discharge-side arc groove 520. From these lubricating oil grooves 57, 58, hydraulic oil is supplied between the cam ring 8 that swings as lubricating oil and the plate surface 50.
A lubricating oil groove 59 is formed on the outer periphery of the suction port 51. The lubricating oil groove 59 is supplied from the lubricating oil suction hole 591 between the cam ring 8 that swings with the hydraulic oil in the first control chamber R1 as lubricating oil and the plate surface 50.
[Leak return hole] (See Fig. 4)
A leak return hole 63 is formed in the rear body 40 and the front body 42. The leak return hole 63 is formed so as to connect the accommodation hole 401 that accommodates the control valve 30 of the rear body 40 and the suction side back pressure port 53 of the front body 42.
In the accommodation hole 401 of the rear body 40, an opening 630 that opens to the inner peripheral side surface is formed. A communication hole 631 is formed on the surface of the opening 630 and the rear body 40 so as to communicate with the outer periphery of the through hole 400. A communication hole 632 is formed in the front body 42 so as to communicate with the opening of the communication hole 631 when the rear body 40 and the front body 42 are assembled. The communication hole 632 is formed toward the inner side of the front body 42. Further, a communication hole 633 is formed so as to communicate the communication hole 632 and the suction side back pressure port 53 from the side surface of the front body 42. The side opening of the front body 42 of the communication hole 633 is closed by a closing plug 634.

[Action]
The operation of the vane pump 1 according to the first embodiment will be described (see FIG. 3).
(Pump action)
By rotating the rotor 6 in a state where the cam ring 8 is eccentrically disposed in the x-axis positive direction with respect to the rotation axis O, the pump chamber r is periodically expanded and contracted while rotating around the rotation axis. On the y-axis negative direction side where the pump chamber r expands in the rotation direction, hydraulic oil is sucked into the pump chamber r from the suction port 43, and from the pump chamber r on the y-axis positive direction side where the pump chamber r shrinks in the rotation direction. The sucked working oil is discharged to the discharge port 44.
Specifically, focusing on a certain pump chamber r, in the suction region, until the vane 7 on the rotation negative direction side of the pump chamber r (hereinafter, rear vane 7) passes through the end point B of the suction-side arc groove 430. In other words, the volume of the pump chamber r increases until the vane 7 on the rotation positive direction side (hereinafter, the front vane 7) passes through the starting point C of the discharge-side arc groove 440. During this time, the pump chamber r communicates with the suction-side arc groove 430, so that hydraulic fluid is sucked from the suction port 43.
In the first confinement region, the rear vane 7 (the surface on the positive rotation side) of the pump chamber r coincides with the end point B of the suction-side arc groove 430, and the front vane 7 (the surface on the negative rotation direction side). However, at the rotational position that coincides with the starting point C of the discharge-side arc groove 440, the pump chamber r does not communicate with the suction-side arc groove 430 and the discharge-side arc groove 440, and is secured in a liquid-tight manner.
After the rear vane 7 of the pump chamber r has passed the end point B of the suction-side arc groove 430 (the front vane 7 has passed the start point C of the discharge-side arc groove 440), the pump is rotated in the discharge region according to the rotation. Since the volume of the chamber r decreases and communicates with the discharge-side arc groove 440, hydraulic oil is discharged from the pump chamber r to the discharge port 44.
In the second confinement region, the rear vane 7 (the surface on the rotation positive direction side) of the pump chamber r coincides with the end point D of the discharge-side arc groove 440, and the front vane 7 (the surface on the rotation negative direction side). At a position that coincides with the starting point A of the suction-side arc groove 430, the pump chamber r does not communicate with the discharge-side arc groove 440 and the suction-side arc groove 430, and is secured in a liquid-tight manner.

In the first embodiment, the first and second confinement areas are each provided by one pitch (one pump chamber r), so that the suction area and the discharge area are prevented from communicating with each other. The pump efficiency can be improved. In addition, it is good also as providing a confinement area | region (space | interval of the suction port 43 and the discharge port 44) over the range of 1 pitch or more. In other words, the angle range of the confinement region can be arbitrarily set as long as the discharge region and the suction region are not communicated with each other.
When the front vane 7 (the surface on the negative rotation direction side) transitions from the first confinement region to the discharge region, the communication between the pump chamber r and the discharge-side arc groove 440 is abruptly caused by the squeezing action of the start end portion 443. Since this is not performed, fluctuations in the pressure of the discharge port 44 and the pump chamber r are suppressed. That is, since the hydraulic oil is prevented from flowing suddenly from the high pressure discharge port 44 into the low pressure pump chamber r, the flow rate supplied from the discharge port 44 to the external pipe connected through the discharge hole 442 is reduced. Rapid decrease is suppressed. Therefore, pressure fluctuation (oil hammer) in the piping can be suppressed. Further, since a rapid increase in the flow rate supplied to the pump chamber r is suppressed, pressure fluctuations in the pump chamber r can also be suppressed. The start end 443 may be omitted as appropriate.
Further, when the front vane 7 (the surface on the negative rotation direction side) moves from the second confinement region to the suction region, the communication between the pump chamber r and the suction side arc groove 430 is abruptly caused by the throttle action of the notch 434. Therefore, fluctuations in pressure in the suction port 43 and the pump chamber r are suppressed. That is, the volume of the pump chamber r is prevented from increasing at a stretch, and the hydraulic oil is prevented from flowing out rapidly from the high-pressure pump chamber r to the low-pressure suction port 43, thereby suppressing the generation of bubbles (cavitation). can do. Note that the notch 434 may be omitted as appropriate.

(Capacity variable action)
When the cam ring 8 swings to the x-axis positive direction side and the eccentricity δ is not zero, the volume of the pump chamber r increases as the rotor 6 rotates on the y-axis negative direction side, and x on the x-axis positive direction side. Maximum when located on an axis. On the y-axis positive direction side, the volume of the pump chamber r decreases as the rotor 6 rotates, and becomes the minimum when positioned on the x-axis on the x-axis negative direction side. At the maximum eccentric position shown in FIG. 2, the volume difference between when the pump chamber r is reduced and when the pump chamber r is reduced is maximized, and the pump capacity is also maximized.
On the other hand, at the minimum eccentric position where the cam ring 8 swings in the x-axis negative direction side and the eccentricity δ is minimized (zero), the pump chamber is rotated as the rotor 6 rotates, both on the y-axis negative direction side and the y-axis positive direction side. The volume of r is neither enlarged nor reduced. In other words, the volume difference between the pump chambers r is minimized (zero), and the pump capacity is also minimized.
Thus, the volume difference changes according to the swinging amount of the cam ring 8, and the pump capacity changes accordingly.
In a state where hydraulic oil is not supplied to the first and second control chambers R1 and R2, the cam ring 8 is urged to the x-axis positive direction side by the spring 12, and the eccentric amount δ is maximum.
The first control chamber R1 is supplied with hydraulic oil from the control valve 30 via the first control oil passage. The supplied hydraulic pressure generates a first hydraulic pressure that presses the cam ring 8 toward the negative x-axis direction against the urging force of the spring 12. The hydraulic oil is supplied from the control valve 30 to the second control chamber R2 via the second control oil passage. The supplied hydraulic pressure generates a second hydraulic pressure that urges the urging force of the spring 12 to press the cam ring 8 toward the positive x-axis direction.
The CVT control unit 300 controls the operation of the control valve 30 and appropriately changes the hydraulic oil (first and second hydraulic pressures acting on the cam ring 8) supplied to the first and second control chambers R1 and R2. The cam ring 8 is swung to change the eccentricity δ. Thereby, the pump capacity is variably controlled.
Specifically, the first hydraulic pressure increases as the operating hydraulic pressure in the first control chamber R1 increases. Further, when the hydraulic oil pressure in the second control chamber R2 increases, the second oil pressure increases. When the sum of the first and second hydraulic pressures is the direction in which the cam ring 8 is pushed in the negative x-axis direction, the urging force by the spring 12 (pushing the cam ring 8 in the positive x-axis direction) is smaller than this hydraulic pressure. Then, the cam ring 8 moves to the x-axis negative direction side. Then, the amount of eccentricity δ becomes small, and the volume difference between the time when the pump chamber r is reduced and the time when the pump chamber r is reduced becomes small, so that the pump capacity decreases.
Conversely, the sum of the first and second oil pressures is the direction in which the cam ring 8 is pushed in the negative direction of the x-axis, and when the urging force by the spring 12 is greater than this oil pressure, When the sum is the direction in which the cam ring 8 is pushed in the x-axis positive direction side, the cam ring 8 moves in the x-axis positive direction side. Then, the amount of eccentricity δ increases, and the volume difference between the time when the pump chamber r is reduced and the time when the pump chamber r is enlarged is increased, so that the pump capacity is increased.
The second control chamber R2 may not be provided, and the control may be performed only by the oil pressure in the first control chamber R1. Moreover, you may utilize things other than a coil spring as an elastic member which urges | biases the cam ring 8. FIG.
In a predetermined high rotation range, the pump capacity is variably controlled in this way, thereby reducing the torque (drive torque) required for driving and minimizing the output. Thereby, loss torque (power loss) can be reduced compared with a fixed displacement pump.

(Power loss reduction by separating back pressure port) (See Fig. 2)
When the rotor 6 rotates, a centrifugal force (a force that moves the vane 7 in the outer diameter direction of the rotor) acts on the vane 7. Therefore, if a predetermined condition such as a sufficiently high rotational speed is set, the vane tip of the vane 7 is prepared. The part 70 protrudes from the slit 61 and comes into sliding contact with the cam ring inner peripheral surface 80 of the cam ring 8. The vane tip portion 70 abuts against the cam ring inner peripheral surface 80, whereby the movement of the vane 7 in the rotor outer diameter direction is restricted. When the vane 7 protrudes from the slit 61, the volume of the back pressure chamber br of the vane 7 is increased. When the vane 7 is immersed (stored) in the slit 61, the volume of the back pressure chamber br of the vane 7 is reduced.
When the rotor 6 rotates in a state where the cam ring 8 is decentered in the x-axis positive direction with respect to the rotation axis, the back pressure chambers br of the vanes 7 that are in sliding contact with the cam ring inner peripheral surface 80 rotate while rotating around the rotation axis. Scale up and down.
Here, on the y-axis negative direction side where the back pressure chamber br expands, if hydraulic oil is not supplied to the back pressure chamber br of the vane 7, the protrusion (jumping) of the vane 7 is hindered, and the vane tip portion 70 moves into the cam ring. There is a possibility that the liquid tightness of the pump chamber r is not ensured without contacting the peripheral surface 80. On the other hand, if the hydraulic oil is not smoothly discharged from the back pressure chamber br of the vane 7 on the positive side in the y-axis direction where the back pressure chamber br shrinks, the vane 7 is prevented from being housed (retracted) into the slit 61 and the vane tip The sliding resistance between the portion 70 and the cam ring inner peripheral surface 80 increases.
In the vane pump 1, hydraulic oil is supplied from the suction-side back pressure port 45 to the back pressure chamber br on the y-axis negative direction side. Thereby, the pop-out property of the vane 7 is improved. On the y-axis positive direction side, the hydraulic oil is discharged from the back pressure chamber br to the discharge side back pressure port 46. Thereby, the sliding resistance of the vane 7 is reduced.

Here, on the y-axis negative direction side, the pressure in the suction port 43 acts on the vane tip portion 70 of the vane 7, and the pressure in the suction side back pressure port 45 acts on the vane base end portion 71 (root). To do. Since the suction side back pressure port 45 communicates with the suction port 43 via the low pressure chamber 491, the pressure in the suction port 43 and the pressure in the suction side back pressure port 45 are substantially equal. Therefore, substantially the same pressure acts on the vane tip 70 and the vane base end 71 of the vane 7. Therefore, for example, compared to the case where high pressure hydraulic oil is supplied to the back pressure chamber br from the discharge side port, the vane tip portion 70 is unnecessarily strongly pressed against the cam ring inner peripheral surface 80 by oil pressure other than centrifugal force. And the loss torque due to friction when the vane 7 is in sliding contact with the cam ring inner peripheral surface 80 is suppressed to a low level. In other words, the sliding resistance of the vane tip 70 to the cam ring inner peripheral surface 80 is reduced, and the power loss is reduced as compared with the case where a high-pressure pump discharge side pressure is applied to all the vane base ends 71 in the suction region. it can.
On the other hand, on the y-axis positive direction side, the pressure in the discharge port 44 acts on the vane tip portion 70 of the vane 7, and the pressure in the discharge-side back pressure port 46 acts on the vane base end portion 71. Since the discharge-side back pressure port 46 communicates with the discharge port 44 via the high-pressure chamber 492, substantially the same pressure acts on the vane distal end portion 70 and the vane base end portion 71 of the vane 7. Therefore, the vane tip portion 70 is suppressed from being unnecessarily strongly pressed against the cam ring inner peripheral surface 80, and the loss torque due to friction when the vane 7 is in sliding contact with the cam ring inner peripheral surface 80 is suppressed low.
Thus, in the vane pump 1, the back pressure port communicating with the back pressure chamber br of the vane 7 is separated on the suction side and the discharge side, and the vane tip portion 70 of the vane 7 is obtained in both the suction process and the discharge process. And substantially the same pressure acts on the vane base end portion 71. For this reason, sliding resistance can be reduced, pressing the vane 7 against the cam ring 8 moderately by centrifugal force. Therefore, wear can be reduced and power loss can be reduced because unnecessary driving torque is not wasted for rotating the rotor 6.
In other words, the vane pump 1 is a so-called low-torque pump that has a low driving torque with respect to the rotational speed and is highly efficient (that is, can improve power consumption by reducing power loss), and has the same physique as compared with a normal variable displacement vane pump. However, it has a feature that the discharge amount is large (that is, it can be downsized).

(Suppression of blow-by by vane pressing) (See Fig. 2)
As described above, the vane 7 in the suction process mainly uses centrifugal force in order to protrude from the state immersed in the slit 61 toward the cam ring inner peripheral surface 80. Therefore, when the internal combustion engine is started or in a low rotation range of the pump such as in an idling state, the centrifugal force is small, the vane 7 does not protrude sufficiently in the suction process, and the vane tip 70 is separated from the cam ring inner peripheral surface 80. There is a risk. That is, the amount of protrusion of the vane is determined according to the force acting in the direction of protruding the vane 7 (or preventing the protrusion). This acting force is mainly determined by the centrifugal force, the viscous resistance of the hydraulic oil, and the frictional force of the vane 7 against the slit 61. Of these, the ratio of centrifugal force is the largest.
When the plurality of pump chambers r in turn reach the first and second confinement regions in accordance with the rotation of the rotor 6, the suction process and the discharge process are switched. If an arbitrary vane 7 with a small protrusion amount is in a state of being separated from the cam ring inner peripheral surface 80 and reaches the rotational position where the suction region and the discharge region are switched, the following problem occurs.
That is, in the vane pump 1, since the first confinement region is set by one pitch, the rear vane 7 (the vane 7 having a small protrusion amount) of a certain pump chamber r (referred to as the first pump chamber r) is provided. When in the first confinement region, the front vane 7 of the first pump chamber r is in the discharge region, and the first pump chamber r is in communication with the discharge port 44, so that the pressure is high. On the other hand, since the rear vane 7 of the pump chamber r (referred to as the second pump chamber r) adjacent to the first pump chamber r in the negative rotation direction is in the suction region, the second pump chamber r is connected to the suction port 43. Is in low pressure.
In this way, when the pressure in the adjacent pump chamber r across a certain vane 7 is low in one pump chamber r and high in the other pump chamber r, the vane 7 protrudes (presses against the cam ring 8). ) Is insufficient, hydraulic oil leaks from the high-pressure pump chamber r to the low-pressure pump chamber r through the gap between the vane tip 70 and the cam ring inner peripheral surface 80 (the hydraulic oil Blowout) occurs. In particular, in a low temperature environment, there is a high possibility that blow-through will occur. In the blow-through, a rapid flow of hydraulic oil occurs.
In this case, the pressure in the discharge port 44 and the suction port 43 varies greatly, and noise is generated. Further, since the pressure in the discharge port 44 periodically decreases as the rotor 6 rotates, it causes the discharge pressure to pulsate. Further, since the discharge amount is reduced and the pressure on the pump discharge side cannot be sufficiently obtained, the pump efficiency is lowered and the startability of the system (CVT100) using the pump discharge pressure is deteriorated.
In the vane pump 1, a high pressure is applied to the back pressure chamber br of the vane 7 before the vane 7 moves to the first confinement region. Therefore, the protrusion of the vane 7 in the first confinement region is secured, and the high-pressure pump chamber r and the low-pressure pump chamber r adjacent to each other with the vane 7 interposed therebetween are liquid-tightly separated (sealed). it can.
Even after the vane 7 moves to the first confinement region, the back pressure chamber br of the vane 7 is communicated with the discharge-side back pressure port 46, and high pressure is applied to ensure the pressing of the vane 7. ing.
In other words, a high pressure is applied to the back pressure chamber br on the vane 7 that divides the pump chamber r in the portion (first confinement region) where the suction process is switched to the discharge process, and the pressure difference between the tip of the vane and the root is caused. The vane tip is pressed against the cam ring inner peripheral surface 80. Thereby, the liquid tightness of the pump chamber r just before switching to the discharge process is ensured, and the gap between the low pressure suction side and the high pressure discharge side is sealed.
Therefore, even if the viscosity of the hydraulic oil is high at the time of cold start or the like, and the pop-out property of the vane 7 due to centrifugal force is poor, the vane 7 can be protruded by hydraulic pressure, and the pump suction / discharge operation can be performed. Therefore, startability at low temperatures can be improved.

(Vane pressing action in the discharge and suction areas)
Here, the hydraulic circuits between the suction ports 43 and 51, the discharge ports 44 and 52, the suction side back pressure ports 45 and 53, and the discharge side back pressure ports 46 and 54 will be described. FIG. 7 is a schematic diagram of a hydraulic circuit.
The hydraulic oil is supplied from the reservoir through the suction passage 64 to the suction ports 43 and 51 through the suction hole 431 and the communication hole 432, and to the suction side back pressure ports 45 and 53 through the communication hole 451. When the vane pump 1 is driven, hydraulic oil continues to be sucked in the suction region, so that the pressure in the suction ports 43 and 51 (suction pressure Pi) is a negative pressure, that is, an atmospheric pressure or less. Since the suction-side back pressure ports 45 and 53 communicate with the suction ports 43 and 51 via the low-pressure chamber 491, the suction-side back pressure ports 45 and 53 are supplied with hydraulic fluid having the suction pressure Pi. Become. Here, the vane 7 in the suction region protrudes from the slit 61 as the rotor 6 rotates. That is, the volume of the back pressure chamber br at the vane base end 71 increases as the rotor 6 rotates. Therefore, a pressure lower than the suction pressure Pi acts in the suction side back pressure ports 45 and 53.
When the vane pump 1 is driven, the pressure of the hydraulic oil rises due to the pump action in the discharge region, so that the pressure in the discharge ports 44 and 52 (discharge pressure Pd) is higher than the atmospheric pressure. Since the discharge-side back pressure ports 46 and 54 communicate with the discharge ports 44 and 52 through the high-pressure chamber 492, the discharge-side back pressure ports 46 and 54 are operated with the discharge pressure Pd at the beginning of the rotation of the rotor 6. Oil will be supplied. Here, the vane 7 in the discharge region is pushed into the slit 61 as the rotor 6 rotates. That is, the volume of the back pressure chamber br at the vane base end portion 71 is reduced as the rotor 6 rotates. Therefore, a pressure higher than the discharge pressure Pd acts in the discharge side back pressure ports 46 and 54.
The hydraulic fluid in the discharge side back pressure ports 46 and 54 is supplied to the discharge ports 44 and 52 from the communication hole 465 through the communication hole 461 and the high pressure chamber 492. The hydraulic fluid compressed in the pump chamber r in the discharge region and the hydraulic oil compressed in the back pressure chamber br in the vane base end portion 71 in the discharge region are supplied to the high pressure chamber 493 through the discharge hole 442. The hydraulic oil in the high pressure chamber 493 is supplied to the first control chamber R1 and the second control chamber R2 through the control valve 30 and to the CVT 100 through the discharge passage 65. Here, a metering orifice is provided between the supply passage to the first control chamber R1 and the supply passage to the second control chamber R2. That is, the hydraulic oil pressure supplied to the first control chamber R1 and the second control chamber R2 has a differential pressure, and the swing amount of the cam ring 8 is determined by the magnitude of the differential pressure.
The control valve 30 generates leak oil. Normally, this leaked oil is recirculated to the reservoir, but in the first embodiment, it is supplied to the suction side back pressure ports 45 and 53 through the leak return hole 63. Thereby, the pressure of the hydraulic oil in the suction side back pressure ports 45 and 53 can be made higher than the suction pressure Pi. Here, although the discharge pressure Pd is supplied to the control valve 30, the pressure of the leaked oil is not so high because the control valve 30 serves as a large orifice, and the amount of leak is also the suction side back pressure ports 45, 53. Less than the amount of hydraulic oil inside. Therefore, the pressure of the hydraulic oil in the suction side back pressure ports 45 and 53 is higher than the suction pressure Pi but only lower than the atmospheric pressure.

<Pressure increasing action of discharge side back pressure port>
Suppose that the pressure in the discharge ports 44 and 52 is equal to the pressure in the discharge-side back pressure ports 46 and 54. In this case, an equal force acts on the vane front end portion 70 and the vane base end portion 71. Therefore, the vane 7 must protrude from the slit 61 only by the centrifugal force generated by the rotation of the rotor 6. At the time of starting the internal combustion engine or at a low pump speed range such as an idling state, the centrifugal force is small, the protrusion of the vane 7 in the discharge region is insufficient, and the vane tip 70 is separated from the cam ring inner peripheral surface 80. There is a fear.
In the vane pump 1 of the first embodiment, as described above, the vane 7 in the discharge region is pushed into the slit 61 according to the rotation of the rotor 6, and the volume of the back pressure chamber br at the vane base end portion 71 is the rotation of the rotor 6. Therefore, it will shrink. Therefore, a pressure higher than the discharge pressure Pd acts in the discharge side back pressure ports 46 and 54.
Further, the communication hole 461 is disposed closer to the negative rotation direction of the discharge-side back pressure arc groove 460, and the diameter is formed substantially equal to the rotor radial width of the discharge-side back pressure arc groove 460. For this reason, hydraulic oil that is higher than the discharge pressure Pd at the discharge-side back pressure ports 46 and 54 is difficult to be discharged due to the orifice effect.
With this configuration, the force acting on the vane tip 70 becomes larger than the force acting on the vane base end 71, and the vane 7 can be brought into contact with the cam ring inner peripheral surface 80.

<Pressure increasing action of suction side back pressure port>
Suppose that the pressure in the suction ports 43 and 51 is equal to the pressure in the suction side back pressure ports 45 and 53. In this case, an equal force acts on the vane front end portion 70 and the vane base end portion 71.
Further, as described above, the vane 7 in the suction region protrudes as the rotor 6 rotates, so that the volume of the back pressure chamber br at the vane base end 71 increases as the rotor 6 rotates. Therefore, the pressure in the suction side back pressure ports 45 and 53 may be smaller than the pressure in the suction ports 43 and 51.
Therefore, the vane 7 must protrude from the slit 61 only by the centrifugal force generated by the rotation of the rotor 6.
At the time of starting the internal combustion engine or at a low pump speed range such as an idling state, the centrifugal force is small, the protrusion of the vane 7 in the discharge region is insufficient, and the vane tip 70 is separated from the cam ring inner peripheral surface 80. There is a fear.
When the back pressure chamber br of the vane 7 is applied to the rotational negative direction ends of the discharge side back pressure ports 46 and 54, a low suction pressure Pi acts on the vane tip 70 and a high pressure on the vane base 71. The discharge pressure Pd acts. At this time, if the vane tip 70 is separated from the cam ring inner peripheral surface 80, the vane 7 suddenly protrudes and collides with the cam ring inner peripheral surface 80 to generate noise. In addition, a phenomenon in which hydraulic oil leaks from the high-pressure pump chamber r to the low-pressure pump chamber r (operating oil blow-through) occurs.
In the vane pump 1 of the first embodiment, the leak oil of the control valve 30 is supplied to the suction side back pressure ports 45 and 53 through the leak return hole 63 as described above.
With this configuration, it is possible to make the pressure of the hydraulic oil in the suction side back pressure ports 45 and 53 higher than the suction pressure Pi, and the force acting on the vane base end portion 71 is greater than the force acting on the vane tip end portion 70. Can be bigger. Therefore, the vane 7 can always be brought into contact with the cam ring inner peripheral surface 80, and the collision of the vane 7 with the cam ring inner peripheral surface 80 can be reduced, and the generation of noise can be suppressed.
Here, in order to make the vane 7 project reliably, the pressure of the hydraulic oil in the suction side back pressure ports 45 and 53 may be higher than the atmospheric pressure. However, the vane pump 1 of the first embodiment is a low torque pump. In the low torque pump, as described above, substantially the same pressure acts on the vane tip 70 and the vane base end 71 of the vane 7, so that the vane tip 70 is unnecessarily strong on the cam ring inner peripheral surface 80. Pressing is suppressed, and loss torque due to friction when the vane 7 is in sliding contact with the cam ring inner peripheral surface 80 is suppressed low.
In the vane pump 1 according to the first embodiment, the pressure of the hydraulic fluid in the suction-side back pressure ports 45 and 53 is higher than the pressure of the hydraulic fluid in the suction ports 43 and 51 in a region lower than the atmospheric pressure. Torque is suppressed to realize a low torque pump.

[effect]
Hereinafter, effects of the vane pump 1 ascertained from the first embodiment will be listed.
(1) A rotor 6 that is rotationally driven by a drive shaft 5, a vane 7 that can be projected and retracted in each of a plurality of slits 61 formed on the outer periphery of the rotor 6, and a cam ring that is disposed so as to surround the rotor 6. 8, a plate 41 which is disposed on the axial side surface of the cam ring 8 and the rotor 6 and forms a plurality of pump chambers r together with the cam ring 8, the rotor 6 and the vane 7, and a through hole 400. The plate 41 is accommodated in the rear body 40, the rear body 40 accommodating the cam ring 8, the rotor 6 and the vane 7 in the through hole 400, and the through hole 400 of the rear body 40 is closed. A front body 42 forming a pump chamber r, side surfaces of the plate 41 and the front body 42, the rotor 6 and the vane 7; The suction ports 43 and 51 are formed on the opposite side surface and open to a suction region in which the volumes of the plurality of pump chambers r are increased according to the rotation of the rotor 6, and the suction side pressure is introduced. In addition, in the vane pump 1 including the suction side back pressure ports 45 and 53 communicating with the base end portion of the slit 61 that accommodates the plurality of vanes 7 positioned in the suction region, the suction side back pressure ports 45 and 53 The pressure of the hydraulic oil was made lower than the atmospheric pressure and higher than the pressure of the hydraulic oil in the suction ports 43 and 51.
Accordingly, the pressure of the hydraulic oil in the suction side back pressure ports 45 and 53 can be made higher than the pressure of the hydraulic oil in the suction ports 43 and 51, and the force acting on the vane base end portion 71 is applied to the vane tip end portion 70. It can be larger than the acting force. Therefore, it becomes possible to make the vane 7 contact | abut to the cam ring internal peripheral surface 80, it can reduce that the vane 7 collides with the cam ring internal peripheral surface 80, and generation | occurrence | production of noise can be suppressed. Furthermore, the blow-through of hydraulic oil can be reduced. Further, a low torque pump can be realized by suppressing loss torque.

(2) The discharge ports 44 and 52 that are formed on the opposite side surfaces and open to the discharge region in which the volumes of the plurality of pump chambers r are reduced according to the rotation of the rotor 6, and the hydraulic oil discharged from the discharge ports 44 and 52 And a control valve 30 for controlling the swinging amount of the cam ring 8, and hydraulic oil leaked from the control valve 30 is supplied to the suction side back pressure ports 45 and 53.
Therefore, by supplying the leaked oil from the control valve 30 higher than the suction pressure to the suction side back pressure ports 45 and 53, the pressure of the hydraulic oil at the suction side back pressure ports 45 and 53 is activated by the suction ports 43 and 51. It becomes possible to make it higher than the pressure of oil. Therefore, the force acting on the vane base end portion 71 can be made larger than the force acting on the vane tip end portion 70, and the vane 7 can be brought into contact with the cam ring inner peripheral surface 80. The collision with the peripheral surface 80 can be suppressed, and the generation of noise can be suppressed.

[Other Examples]
As described above, the present invention has been described based on the first embodiment. However, the specific configuration of each invention is not limited to each embodiment, and even if there is a design change or the like without departing from the gist of the invention. Are included in the present invention.
In the first embodiment, the leakage oil of the control valve 30 is supplied to the suction-side back pressure ports 45 and 53 through the leak return hole 63, whereby the pressure of the hydraulic oil in the suction-side back pressure ports 45 and 53 is lower than the atmospheric pressure. The pressure of the hydraulic oil in the suction ports 43 and 51 is made higher. This pressure difference may be caused by the opening area of the suction hole 431 and the communication hole 432 of the suction port 43 and the opening area of the communication hole 451 of the suction side back pressure port 45. Specifically, the sum of the opening areas of the suction port 431 and the communication hole 432 of the suction port 43 is S1, the sum of the flow rates of the suction hole 431 and the communication hole 432 of the suction port 43 is Q1, and the suction side back pressure port 45 When the opening area of the communication hole 451 is S2 and the sum of the flow rates of the communication holes 451 of the suction side back pressure port 45 is Q2 (see FIG. 3), the following equation is satisfied.
(Q1 / S1)> (Q2 / S2)
That is, the ratio of the flow rate Q1 of the working oil flowing into the suction port 43 to the opening area S1 into which the working oil flows into the suction port 43 flows into the suction back pressure port 45 with respect to the opening area S2 into which the working oil flows into the suction side back pressure port 45. It is formed so as to be larger than the ratio of the flow rate Q2 of the hydraulic oil.
With this configuration, the force acting on the vane base end portion 71 can be made larger than the force acting on the vane tip end portion 70, and the vane 7 can be brought into contact with the cam ring inner peripheral surface 80. The collision with the cam ring inner peripheral surface 80 can be suppressed, and the generation of noise can be suppressed.
In the vane pump 1 according to the first embodiment, the leak oil of the control valve 30 is supplied to the suction-side back pressure ports 45 and 53. Instead of this configuration, a passage for supplying hydraulic oil from the reservoir to the suction ports 43 and 51 Orifices may be provided in a shape. Thereby, the pressure of the hydraulic oil in the suction side back pressure ports 45 and 53 can be made higher than the pressure of the hydraulic oil in the suction ports 43 and 51. Specifically, the diameters of the suction holes 431 and the communication holes 432 are reduced.
In the first embodiment, suction ports 43 and 51, discharge ports 44 and 52, suction-side back pressure ports 45 and 53, and discharge-side back pressure ports 46 and 54 are formed on both the plate 41 and the front body 42. Alternatively, it may be provided only on one side.

1 vane pump 6 rotor 7 vane 8 cam ring 30 control valve 40 rear body 41 plate 42 front body 43 discharge port 44 suction side back pressure port 45 discharge side back pressure port 51 suction port 52 discharge port 53 suction side back pressure port 54 discharge side back pressure Port 61 slit
400 through hole
402 Bottom r Pump room

Claims (2)

A rotor driven to rotate by a drive shaft;
A vane accommodated in each of a plurality of slits formed on the outer periphery of the rotor so as to be able to project and retract;
A cam ring that surrounds the rotor and is swingably disposed;
A plate which is disposed on an axial side surface of the cam ring and the rotor and forms a plurality of pump chambers together with the cam ring, the rotor and the vane;
A rear body that has an opening, houses the plate at the bottom of the opening, and houses the cam ring, the rotor, and the vane in the opening;
A front body that closes the opening of the rear body and forms a plurality of pump chambers together with the cam ring, the rotor, and the vane;
A side surface of the plate and / or the front body, which is formed on an opposing side surface facing the rotor and the vane, opens to a suction region in which the volumes of the plurality of pump chambers are increased according to the rotation of the rotor. A suction port;
A suction-side back pressure port formed on the opposite side surface, to which suction-side pressure is introduced, and communicated with a base end portion of the slit accommodating the plurality of vanes located in the suction region;
A discharge port that is formed on the opposite side surface and opens to a discharge region in which the volumes of the plurality of pump chambers are reduced according to the rotation of the rotor;
A control valve for controlling the swing amount of the cam ring by the hydraulic oil discharged from the discharge port;
Vane pump with
By supplying the hydraulic oil leaked from the control valve to the suction side back pressure port, the pressure of the hydraulic oil in the suction side back pressure port is lower than the atmospheric pressure and lower than the pressure of the hydraulic oil in the suction port. The vane pump is characterized in that it is also higher. A rotor driven to rotate by a drive shaft;
A vane accommodated in each of a plurality of slits formed on the outer periphery of the rotor so as to be able to project and retract;
A cam ring that surrounds the rotor and is swingably disposed;
A plate which is disposed on an axial side surface of the cam ring and the rotor and forms a plurality of pump chambers together with the cam ring, the rotor and the vane;
A rear body that has an opening, houses the plate at the bottom of the opening, and houses the cam ring, the rotor, and the vane in the opening;
A front body that closes the opening of the rear body and forms a plurality of pump chambers together with the cam ring, the rotor, and the vane;
A side surface of the plate and / or the front body, which is formed on an opposing side surface facing the rotor and the vane, opens to a suction region in which the volumes of the plurality of pump chambers are increased according to the rotation of the rotor. A suction port;
A first opening area of a communication hole formed in the plate and opening into the suction port;
A suction-side back pressure port formed on the opposite side surface, to which suction-side pressure is introduced, and communicated with a base end portion of the slit accommodating the plurality of vanes located in the suction region;
A second opening area of a communication hole formed in the plate and opening to the suction side back pressure port;
Vane pump with
The ratio of the flow rate of the working oil flowing into the suction port to the first opening area into which the working oil flows into the suction port is the suction back pressure with respect to the second opening area through which the working oil flows into the suction side back pressure port. A vane pump characterized in that it is larger than the ratio of the flow rate of hydraulic oil flowing into the port .

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