JP2012087777A - Vane pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vane pump that easily controls an ejection flow rate without complicating control.SOLUTION: The vane pump includes, as a control valve: a spool switching an oil path to a control room for controlling a swing of a cam ring; an elastic body applying a predetermined load to the spool; a solenoid applying a desired biasing force in an operative direction of the spool; and an adjustment mechanism for adjusting the predetermined load of the elastic body.

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, the vane pump described in Patent Document 1 is provided with a solenoid that applies an urging force to a control valve that controls the eccentric amount of the cam ring in order to set the discharge flow rate to a desired value, thereby applying a predetermined urging force. The discharge flow rate is controlled.

JP 2001-304139 A

However, in the vane pump described in Patent Document 1, the initial set load of the coil spring of the control valve cannot be adjusted. Therefore, in order to adjust the initial set load, it is necessary to cope with the control of the solenoid. There was a risk of complications. In addition, since the direction in which the coil spring is urged is the same as the direction in which the solenoid is urged, the energy efficiency deteriorates because the minimum discharge flow rate is set higher when the initial set load is too high. There was a problem.
An object of the present invention is to provide a vane pump capable of easily controlling the discharge flow rate without complicating the control.

  In order to achieve the above object, a vane pump according to the present invention includes, as a control valve, a spool that switches an oil passage to a control chamber that controls the swing of a cam ring, an elastic body that applies a predetermined load to the spool, A solenoid for applying a desired urging force in the operation direction and an adjustment mechanism for adjusting a predetermined load on the elastic body are provided.

  Accordingly, the initial set load of the elastic body can be adjusted, and a stable discharge flow rate can be obtained without complicating the control.

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. It is the schematic showing the relationship between the control part of Example 1, and a control room. It is a characteristic view showing the relationship between the rotation speed of the variable displacement vane pump of Example 1 and the discharge flow rate.

[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 large 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, The plate 41 that forms a plurality of pump chambers r together with the rotor 6 and the vane 7 and the accommodation hole 400 are accommodated. The plate 41 is accommodated in the bottom 402 of the accommodation hole 400, and the cam ring 8, the rotor 6, The rear body 40 that accommodates the vane 7 and the accommodation hole 400 of the rear body 40 are closed, and a plurality of them are provided together with the cam ring 8, the rotor 6, and the vane 7. 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 accommodation hole 400 extending in the z-axis direction. An annular adapter ring 9 is installed in the accommodation 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. The amount of eccentricity of the central axis P of the cam ring 8 with respect to the rotation axis O is denoted by δ. 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.
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 and suction holes 431 and 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. At the start end of the suction-side arc groove 430, a main body start end 433 formed in a substantially semicircular shape convex in the negative rotation direction and a notch 434 continuous with the main body start end 433 are formed. 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 width of the suction-side arc groove 430 in the rotor radial direction is substantially the same in the entire rotation direction range (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.
The suction 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 slightly less than 20% of the thickness of the plate 41 (z-axis direction) between the main body start end 433 and the suction holes 431 and 432 and the terminal end 436. Have.
A slope is provided between the main body start end portion 433 and the suction hole 432, and is formed so as to be gradually deeper in the rotation direction and to have the same depth as the plate 41 at a portion reaching the suction 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 has a discharge-side arc groove 440 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.

The start end 443 of the discharge-side arc groove 440 is formed to extend from the start point C to the edge 445 of the discharge hole 441 on the rotation negative direction side. 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 448 provided between the discharge holes 441 and 442 of the discharge-side arc groove 440 is approximately 25% of the thickness (in the z-axis direction) of the plate 41. 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 suction 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 suction hole 451 opens at a position overlapping the suction hole 432 of the suction-side arc groove 430 in the rotor radial direction near the rotation negative direction (starting point a side) of the suction-side back pressure arc groove 450. The suction 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 one pitch. The suction hole 451 is formed so as to penetrate the plate 41 in the z-axis direction, and communicates with the suction hole 431 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 451. 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 suction hole 451 is inclined, and gradually becomes deeper toward the communication hole 451 in the negative rotation direction, and at the portion reaching the suction hole 451, the depth is the same 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 discharge 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 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 suction holes 431 and 432 of the suction port 43 formed in the plate 41 and the z-axis negative direction side opening of the suction hole 451 of the suction side back pressure port 45. Yes. 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 discharge 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. Further, the high pressure chamber 492 and the discharge chamber 493 are in communication.
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. 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 and suction holes 511 and 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 width of the suction-side arc groove 510 in the rotor radial direction is substantially the same in the entire rotation direction range.
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 suction hole 512 is opened adjacent to the suction hole 511 on the end side in the rotation direction. The suction hole 512 has a rotor radial width that is substantially equal to the suction-side arc groove 510 and a length in the rotational direction of approximately one pitch. The suction 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 a notch 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.
A notch 521 is formed at the end of the discharge-side arc groove 520 on the negative rotation direction side. The notch 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. In addition, the discharge-side arc groove 520 is on the negative side in the rotation direction, and the boundary portion with the notch 521 is formed in a substantially semicircular shape convex toward the negative rotation direction. The edge of the notch 521 on the rotation negative direction side 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 includes a suction side back pressure arc groove 530 and a suction 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 suction hole 531 opens at a position overlapping the suction hole 512 of the suction side arc groove 510 in the rotor radial direction. The suction hole 531 has a substantially oval shape when viewed from the z-axis direction, the width in the rotor radial direction is substantially equal to the suction-side back pressure arc groove 530, and the length in the rotation direction is approximately one 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 notch 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.

[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 spool valve that controls the inflow / outflow of the working fluid into the first control chamber R1 and the second control chamber R2, and includes a spool 302 accommodated in the accommodation hole 401 in the rear body 40, and a solenoid for the spool 302. A spring 303 biased toward the 301 side, an adjustment mechanism 304 that adjusts a retaining position (spring set load) of the spring 303, and a solenoid 301 that imparts a biasing force as required in a direction opposite to the load direction of the spring 303 of the spool 302 And a plunger 301a.
An upstream port 401a to which discharge pressure on the upstream side of a metering orifice 700 described later is supplied is formed at the end of the accommodation hole 401 on the positive side in the x-axis direction. A first passage 31 is opened adjacent to the upstream port 401a on the negative side in the x-axis direction, and the first passage 31 is disposed between the upstream port 401a and the first land portion 302a of the spool 302 so that the first passage 31 can communicate with or cut off. On the other hand, a downstream port 401b to which a discharge pressure (that is, a pressure discharged to the CVT) downstream of a metering orifice 700, which will be described later, is formed at the end of the accommodation hole 401 on the x-axis negative direction side. ing. A second passage 32 is opened adjacent to the downstream side port 401b on the positive side in the x-axis direction, and the second passage 32 is disposed between the downstream port 401b and the second land portion 302b of the spool 302 so as to be able to communicate or block.
FIG. 6 is a schematic diagram illustrating a relationship between the control unit and the control room according to the first embodiment. On the passage connecting the discharge chamber 493 and the discharge passage 65, the upstream oil passage 65a branches upstream from the metering orifice 700 and is connected to the upstream port 401a, and downstream from the metering orifice 700. And a downstream oil passage 65b connected to the downstream port 401b.

  Here, the adjustment mechanism 304 will be described in detail. The rear body 40 is formed with an adjustment screw hole 401c that penetrates the rear body and has a screw formed on the inner periphery at the end on the x-axis negative direction side of the accommodation hole 401. A smooth surface 401d surrounding the adjustment screw hole 401c is formed on the outer wall surface of the rear body 40 in which the adjustment screw hole 401c is formed. A cylindrical positioning bolt 304a having a screw threadedly engaged with the adjustment screw hole 401c on the outer periphery is attached to the adjustment screw hole 401c. The positioning bolt 304a has a protrusion 304a1 that holds the spring 303 at the end facing the accommodation hole 401, and prevents the spring 303 from falling off in the radial direction. Further, a notch or the like that engages with a tool such as a driver is formed at the other end so that the axial position with respect to the rear body 40 can be adjusted. A nut 304b that is fixed to the rear body 40 after axial positioning is attached to the positioning bolt 304a. By tightening the nut 304b, an axial force can be generated between the smooth surface 401d, and the positioning bolt 304a is firmly fixed to the adjustment screw hole 401c of the rear body 40 and a sealing property is secured.

[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)
First, the non-operating state of the solenoid 301 will be described with reference to FIGS. FIG. 7 is a characteristic diagram showing the relationship between the rotational speed of the variable displacement vane pump of Example 1 and the discharge flow rate. An initial set load is applied to the spool 302 by the spring 303 on the positive side in the x-axis direction. When the flow rate is relatively small at the initial stage of pump operation, the differential pressure across the metering orifice 700 is not so large. Since the spool 302 is biased in the positive x-axis direction by the load, the first land portion 302a blocks the upstream port 401a and the first passage 31, and the second land portion 302b The two passages 32 communicate with each other. As a result, no discharge pressure is supplied to the first control chamber R1, and discharge pressure is supplied to the second control chamber R2, so that the cam ring 8 is in an eccentric state and the pump discharge flow rate increases in accordance with the rotational speed. (Refer to the fixed capacity region (a) in FIG. 7).
When the discharge flow rate of the pump increases, the differential pressure between the upstream side and the downstream side of the metering orifice 700 increases, and the upstream side has a higher pressure than the downstream side. At this time, a large force acting on the negative side of the x-axis acts on the first land portion 302a of the spool 302, and an initial set load of the spring 303 and a force on the positive side of the x-axis acting on the second land portion 302b. A force exceeding the total begins to act. The first land portion 302a communicates the upstream port 401a and the first passage 31, and the second land portion 302b blocks the downstream port 401b and the second passage 32. As a result, a high discharge pressure upstream of the metering orifice 700 is supplied to the first control chamber R1, and no discharge pressure is supplied to the second control chamber R2, so the eccentric amount of the cam ring 8 is reduced, Even if the pump speed increases, the pump discharge flow rate does not increase. If the pump discharge flow rate decreases too much, the differential pressure between the upstream side and the downstream side of the metering orifice 700 decreases, so that the cam ring 8 is decentered again and the discharge flow rate is increased appropriately (discharge flow control in FIG. 7). Area (b)).

  When the solenoid 301 is in an inoperative state, only the hydraulic pressure is the force that opposes the initial set load of the spring 303. Therefore, if the discharge flow rate does not increase, a sufficient differential pressure cannot be secured above and below the metering orifice 700. Therefore, after a relatively high discharge flow rate is achieved, a constant flow rate is maintained. Next, when the solenoid 301 is energized to generate a predetermined urging force, the same effect as that obtained by changing the initial set load of the spring 303 to a small value is obtained, so that the spool 302 is switched at an earlier timing than when the solenoid 301 is not operated. Therefore, even if there is no large differential pressure above and below the metering orifice 700, the spool 302 operates with a slight differential pressure, and after a relatively low discharge flow rate is achieved, a constant flow rate is maintained. That is, the discharge flow rate can be controlled by the urging force generated by the solenoid 301. In the CVT control unit 300, the line pressure is appropriately controlled in accordance with the traveling conditions such as the accelerator opening, the engine speed, and the vehicle speed. Therefore, when a high discharge flow rate is required, the current (electromagnetic force) energizing the solenoid 301 is turned off or small, and when a low discharge flow rate is required, the current (electromagnetic force) energizing the solenoid 301 is increased. To do.

(Operation related to the adjustment mechanism)
Next, the reason why the adjustment mechanism 304 is provided will be described. As described above, when the variable displacement vane pump according to the first embodiment reaches a predetermined discharge flow rate, the variable displacement vane pump controls the discharge flow rate to be constant by the operation of the control valve 30. Where the discharge flow rate is made constant is determined by the relationship between the current value energized to the solenoid 301 and the initial set load of the spring 303. Here, since the initial set load of the spring 303 is determined by the spring constant and the amount of contraction of the spring 303, it is easily affected by variations in spring characteristics. In order to cope with this variation, for example, it is conceivable to control the discharge flow rate by correcting the current value energized by the solenoid 301. However, when dealing with the control, it is necessary to incorporate the correction logic in the control logic. When the development of the CVT control unit 300 and the development of the pump are performed separately, the logic is changed or added. Is often difficult to request. Further, in the case of adjusting with the current value, if it is necessary to pass an unnecessary current value, it eventually causes deterioration of fuel consumption.
Therefore, the initial set load is adjusted by a mechanically configured adjusting mechanism 304. That is, since the positioning bolt 304a can adjust the axial position with respect to the accommodation hole 401, for example, when the initial set load is considered to be small, the positioning bolt 304a is further screwed into the accommodation hole 401, and the nut 304b at that position. Tighten. As a result, the amount of contraction of the spring 303 can be controlled, the initial set load can be finely adjusted mechanically, and there is no need to request any special change or addition of control logic.

  In addition, since the variable displacement vane pump of the first embodiment is used for supplying hydraulic pressure to the automatic transmission, it is desirable to ensure a maximum discharge flow rate when the solenoid 301 or the like fails. This is because an insufficient discharge flow rate may cause slippage due to belt slip in the automatic transmission or insufficient fastening force of a clutch or the like, which may cause a secondary failure that affects durability. For this purpose, the solenoid 301 is installed at a position facing the direction in which the initial set load of the spring 303 acts. In other words, the spring 303 and the solenoid 301 are arranged at positions that oppose each other via the spool 302, and the position at which the spring 303 is installed does not require a configuration other than the rear body 40. 401c can be formed easily.

[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, the rear body 40 that houses the cam ring 8, the rotor 6, and the vane 7 in the housing hole 400, the housing hole 400 of the rear body 40 is closed, and a plurality of pump chambers r are formed together with the cam ring 8, the rotor 6, and the vane 7. Is formed on the side surfaces of the front body 42, the plate 41 and the front body 42 that face the rotor 6 and the vane 7, and the volume of the plurality of pump chambers r increases as the rotor 6 rotates. The suction ports 43 and 51 that open to the region and the discharge ports that are formed on the opposite side surfaces and reduce the volume of the plurality of pump chambers r as the rotor 6 rotates. And a control valve 30 for controlling the swing amount of the cam ring 8 by hydraulic fluid discharged from the discharge ports 44 and 52. The control valve 30 swings the cam ring 8. A spool 302 that switches an oil path to the first control chamber R1 and the second control chamber R2 to be controlled, a spring 303 (elastic body) that applies an initial set load (predetermined load) to the spool 302, and an operating direction of the spool 302 And a solenoid 301 for applying a desired urging force, and an adjustment mechanism 304 for adjusting the amount of contraction of the spring 303 (predetermined load on the elastic body).
Therefore, the initial set load of the spring 303 can be adjusted, and a stable discharge flow rate can be obtained without complicated control. Although a spring is used as the elastic body, an elastic force such as rubber or resin may be used. Further, although the predetermined load is adjusted by the amount of contraction of the spring, a configuration in which the load is adjusted by changing the characteristics of the spring or by other means is also included in the present invention.

  (2) The solenoid 301 is provided at a position facing the spring 303 with the spool 302 interposed therebetween. Therefore, when the adjustment mechanism 304 is provided, the configuration of the solenoid 301 does not get in the way, and the adjustment mechanism 304 can be easily arranged.

  (3) The hydraulic oil discharged from the discharge port is the hydraulic oil used in the CVT, and the solenoid 301 is requested by a small current when the required discharge flow rate is large according to the request of the CVT. A large current flows when the discharge flow rate is small. At the time of failure of a solenoid or the like, a high value is desirable as the discharge flow rate from the viewpoint of avoiding secondary failure in CVT. At this time, the discharge flow rate becomes maximum when the solenoid is not operated, so that high reliability can be ensured.

(4) The adjustment mechanism 304 includes an accommodation hole 401 that accommodates the spool 302 in the rear body 40, an adjustment screw hole 401c that penetrates from the accommodation hole 401 to the outside of the rear body 40 and has a screw formed on the inner periphery, Are formed with a screw that is screwed into the adjustment screw hole 401c, and a cylindrical positioning bolt 304a (adjustment member) that contacts the end of the spring 303, and a nut that fixes the positioning bolt 304a to the rear body 40 from the outside. 304b (fixing means). Therefore, the initial set load can be adjusted with a simple configuration. The adjusting member is not limited to a bolt or the like. For example, as long as the adjusting member can be fixed to the rear body by caulking, an adhesive, or the like, it is included in the present invention even if there is no fixing means such as a nut. .
[Other Examples]
The variable displacement vane pump of the present invention has been described based on the embodiments. However, the specific configuration of the present invention is not limited to the embodiments, and there are design changes and the like without departing from the scope of the invention. Is included in the present invention.

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
304 Adjustment mechanism
400 receiving hole
402 Bottom r Pump room

Claims (4)

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 rear body that houses the cam ring, the rotor and the vane in an 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 suction port that is formed on a side surface facing the rotor and the vane and opens to a suction region in which the volumes of the plurality of pump chambers expand according to the rotation of the rotor;
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;
With
The control valve applies a desired urging force in the operating direction of the spool, a spool that switches an oil passage to a control chamber that controls swing of the cam ring, an elastic body that applies a predetermined load to the spool, and the spool. A solenoid, and an adjustment mechanism for adjusting a predetermined load on the elastic body;
The vane pump characterized by having. The vane pump according to claim 1, wherein
The vane pump, wherein the solenoid is provided at a position facing the elastic body with the spool interposed therebetween. The vane pump according to claim 1 or 2,
The hydraulic oil discharged from the discharge port is hydraulic oil used in an automatic transmission of a vehicle,
The solenoid is a vane pump according to the demand of the automatic transmission, wherein a small current flows when the requested discharge flow rate is large, and a large current flows when the requested discharge flow rate is small. The vane pump according to any one of claims 1 to 3,
The adjusting mechanism includes an accommodation hole for accommodating the spool in the rear body,
An adjustment screw hole penetrating from the accommodation hole to the outside of the rear body and having a screw formed on the inner periphery thereof;
A columnar adjustment member that is formed on the outer periphery with a screw that is screwed into the adjustment screw hole, and that contacts the end of the elastic body;
Fixing means for fixing the adjustment member to the rear body from the outside;
A vane pump characterized by comprising:

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