JP2009047041A - Variable displacement vane pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a variable displacement vane pump which improves fuel economy by reducing a relief amount while suppressing the increase of the pump workload. <P>SOLUTION: The variable displacement vane pump has a metering orifice provided on a discharge passage connected to a discharge port, a high-pressure chamber where an upstream side pressure of the metering orifice is introduced, an intermediate-pressure chamber where a downstream side pressure is introduced, and a low-pressure chamber connected to a reservoir tank for storing working oil. The variable displacement vane pump has a pressure control means for controlling the pressure introduced into a first fluid pressure chamber or a second fluid pressure chamber, a relief valve which is provided between the downstream side of the metering orifice and the reservoir tank, opens the valve when it is at the predetermined pressure or more and discharges the pressure at the downstream side of the metering orifice to the reservoir tank side, and a variable throttle mechanism for reducing the sectional area of a flow passage of the metering orifice when at least the relief valve is opened. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a variable displacement pump, and more particularly to a variable displacement vane pump for power steering.

Conventionally, the variable displacement vane pump described in Patent Document 1 has a relief valve built in the control valve, and when the discharge side pressure exceeds a predetermined pressure, the pressure is released to the reservoir tank. Yes.
Japanese Patent Laid-Open No. 2003-21076

  However, in the above prior art, in order to improve fuel efficiency by reducing the amount of hydraulic oil relief from the relief valve by reducing the pilot orifice, the relief valve itself vibrates due to the vibration of the hydraulic oil when it passes through the pilot orifice. End up. If the relief amount is reduced by using a damper orifice instead of the pilot orifice in order to eliminate this vibration, the hydraulic oil leaks from the annular portion of the control valve.

  For this reason, there has been a problem that the valve differential pressure is reduced, the control flow rate in the high pressure state is increased, the pump work amount is increased, and the fuel consumption reduction effect due to the reduction of the hydraulic oil relief amount is offset.

  The present invention has been made paying attention to the above problems, and its object is to provide a variable displacement vane pump in which the amount of relief is reduced and the fuel consumption is improved while suppressing an increase in pump work. is there.

  In order to achieve the above object, according to the present invention, a pump body, a drive shaft pivotally supported by the pump body, a rotor provided in the pump body and driven to rotate by the drive shaft, and a circumference of the rotor A plurality of pumps together with the rotor and the vane on the inner peripheral side, and a vane disposed in a slot provided in a plurality of directions so as to be freely retractable and provided in the pump body so as to be eccentric. A cam ring forming a chamber; a first plate member and a second plate member provided on both sides in the axial direction of the cam ring; and the first plate member or the second plate member, provided on at least one side, A suction port that opens to a region where the volume of the plurality of pump chambers increases, and a discharge port that opens in a direction in which the volume of the plurality of pump chambers decreases, A first fluid pressure chamber provided on the outer peripheral side of the cam ring and an outer peripheral side space of the cam ring provided on the side where the discharge amount increases, and a second fluid pressure chamber provided on the side where the discharge amount decreases , A sealing member that is defined in the above, a metering orifice provided in a discharge passage connected to the discharge port, a high-pressure chamber into which an upstream pressure of the metering orifice is introduced, and a downstream pressure are introduced A pressure control means for controlling a pressure introduced into the first fluid pressure chamber or the second fluid pressure chamber, and having a medium pressure chamber and a low pressure chamber connected to a reservoir tank storing hydraulic oil; A relief valve that is provided between the downstream side of the metering orifice and the reservoir tank, opens when the pressure is equal to or higher than a predetermined pressure, and discharges the pressure downstream of the metering orifice to the reservoir tank side; At least when the relief valve is opened, it was decided to have a variable throttle mechanism throttling the flow path cross-sectional area of the metering orifice.

  Therefore, it is possible to provide a variable displacement vane pump that reduces the amount of relief while suppressing an increase in pump work and improves fuel efficiency.

  Hereinafter, the best mode for realizing the variable displacement vane pump of the present invention will be described based on the embodiments shown in the drawings.

[Outline of vane pump]
Example 1 will be described. FIG. 1 is an axial sectional view of the vane pump 1, and FIG. 2 is a radial sectional view. FIG. 2 shows the case where the cam ring 4 is located in the most negative y-axis direction (maximum eccentricity). O _C the center of the cam ring 4, _{O R} is the center of the drive shaft 2.

  The axial direction of the drive shaft 2 is the x-axis, and the direction in which the drive shaft is inserted into the first and second housings 11 and 12 is the positive direction. Further, the axial direction of the spring 91 (see FIG. 2) that restricts the swinging of the cam ring 4 and the direction in which the cam ring 4 is urged is the y-axis negative direction, the axis orthogonal to the x and y axes, and the inlet IN The side is the z-axis positive direction.

  The vane pump 1 includes a drive shaft 2, a rotor 3, a cam ring 4, an adapter ring 5, and a pump body 10. The drive shaft 2 is connected to the engine via a pulley and rotates integrally with the rotor 3.

  A plurality of slots 31, which are axial grooves, are formed radially on the outer periphery of the rotor 3, and vanes 32 are inserted into the slots 31 so as to be able to protrude and retract in the radial direction. Further, a back pressure chamber 33 is provided at an inner diameter side end portion of each slot 31, and pressure oil is supplied to urge the vane 32 radially outward.

  The pump body 10 is formed of a first housing 11 and a second housing 12 (first member). The first housing 11 has a bottomed cup shape that opens to the positive side of the x-axis, and a disk-shaped pressure plate 6 (second member) is accommodated in the bottom portion 11a. The adapter ring 5, the cam ring 4, and the rotor 3 are accommodated in the pump element accommodating portion 11 b that is the inner peripheral portion of the first housing 11 and on the positive side of the pressure plate 6 in the x-axis direction.

  The second housing 12 is in liquid-tight contact with the adapter ring 5, the cam ring 4, and the rotor 3 from the positive side of the x axis, and the adapter ring 5, the cam ring 4, and the rotor 3 are sandwiched between the pressure plate 6 and the second housing 12. The Rukoto.

  Suction ports 62 and 121 and discharge ports 63 and 122 are provided on the x-axis positive side surface 61 of the pressure plate 6 and the x-axis negative direction side surface 120 of the second housing 12, respectively, and are connected to the suction port IN and the discharge port OUT. The hydraulic oil is supplied to and discharged from the pump chamber B formed between the rotor 3 and the cam ring 4. The suction port IN and the control valve 7 are connected by an oil passage 7a.

  The adapter ring 5 is a substantially elliptical annular member having a major axis on the y-axis side and a minor axis on the z-axis side. The adapter ring 5 is accommodated in the first housing 11 on the outer peripheral side and the cam ring 4 on the inner peripheral side. To dispose. The adapter ring 5 is restricted from rotating with respect to the first housing 11 by the pin 40 so as not to rotate in the first housing 11 when the pump is driven.

  The cam ring 4 is a substantially perfect circular ring member, and the outer periphery thereof is provided with substantially the same diameter as the short axis of the adapter ring 5. Therefore, by being accommodated in the substantially elliptical adapter ring 5, a fluid pressure chamber A is formed between the inner periphery of the adapter ring 5 and the outer periphery of the cam ring 4, and the cam ring 4 extends in the y-axis direction within the adapter ring 5. It can swing.

  Further, a seal member 50 is provided at the end in the z-axis positive direction of the adapter ring inner peripheral surface 53, and a support surface N is formed at the end in the z-axis negative direction. The adapter ring 5 locks the cam ring 4 in the negative z-axis direction on the support surface N.

  A pin 40 (second seal member) is provided on the support surface N, and the fluid pressure chamber A between the cam ring 4 and the adapter ring 5 is defined by the pin 40 and the seal member 50 in the y-axis negative and positive directions. Thus, the first and second fluid pressure chambers A1 and A2 are formed.

  Here, since the cam ring 4 swings while rolling on the support surface N, the volumes of the fluid pressure chambers A1 and A2 change. However, the z-axis negative direction support surface N rotates counterclockwise around the y axis as the center. Parallel to the ξ axis rotated in the direction. That is, the support surface N is inclined to the z-axis positive direction side as it goes to the y-axis positive direction side, and the cam ring 4 is easily swung in the y-axis negative direction by the inclined support surface N.

  The outer diameter of the rotor 3 is provided smaller than the inner diameter 41 of the cam ring, and is accommodated on the inner peripheral side of the cam ring 4. Even when the cam ring 4 swings and the relative position of the rotor 3 and the cam ring 4 changes, the outer periphery of the rotor 3 is provided so as not to contact the inner periphery 41 of the cam ring.

  Further, when the cam ring 4 is positioned most in the y-axis negative direction due to swinging, the distance L between the cam ring inner periphery 41 and the rotor 3 outer periphery is maximum on the y-axis negative direction side. When the cam ring 4 is positioned most in the y-axis positive direction, the distance L is similarly minimum on the y-axis positive direction side.

  The radial length of the vane 32 is larger than the maximum value of the distance L. Therefore, the vane 32 is always inserted into the slot 31 regardless of the relative position between the cam ring 4 and the rotor 3, and the cam ring inner periphery 41. It will maintain the state contact | abutted to. As a result, the vane 32 constantly receives the back pressure from the back pressure chamber 33 and comes into liquid tight contact with the cam ring inner periphery 41.

  Therefore, the region between the cam ring 4 and the rotor 3 is always liquid-tightly defined by the adjacent vanes 32 to form the pump chamber B. If the rotor 3 and the cam ring 4 are in an eccentric state due to the swing, the volume of each pump chamber B changes as the rotor 3 rotates.

  The suction ports 62 and 121 and the discharge ports 63 and 122 provided in the pressure plate 6 and the second housing 12 are provided along the outer periphery of the rotor 3, and supply and discharge of hydraulic oil is performed by changing the volume of each pump chamber B. Is called.

  A radial through hole 51 is provided at the y-axis positive end of the adapter ring 5. Further, a plug member insertion hole 114 is provided at the end of the first housing 11 in the positive direction of the y axis, and a bottomed cup-shaped plug member 90 is inserted to make the first and second housings 11 and 12 liquid-tight. Keep.

  A spring 91 is inserted into the inner periphery of the plug member 90 so as to be expandable and contractible in the y-axis direction, passes through the radial through hole 51 of the adapter ring 5 and abuts on the cam ring 4, and urges in the negative y-axis direction.

  The spring 91 urges the cam ring 4 in the direction in which the swing amount becomes maximum (the negative direction of the y-axis), and stabilizes the discharge amount (cam ring 4 swing position) at the time of starting the pump where the pressure is not stable.

[Control valve]
The control valve 7 is a mechanical valve that is driven based on the discharge pressure and the suction pressure, and is accommodated in a valve housing hole 115 provided on the positive side of the first housing 11 in the z-axis direction. The control valve 7 is formed of a spool 71 and a spring 72, and a relief valve 80 is provided on the inner peripheral side of the bottomed cylindrical spool 71.

(spool)
The spool 71 is a hollow cylindrical member whose bottom 71a, which is the end on the positive side of the y axis, is closed. The spool 71 is urged toward the negative side of the y axis by the spring 72 in the opening 71b, which is the end on the positive side of the y axis. . Further, a seal portion 71c is provided on the outer periphery of the spool 71, and this seal portion 71c abuts the inner periphery of the valve housing hole 115 in a liquid-tight manner.

Further, the opening 71b is in liquid-tight contact with the inner periphery of the valve housing hole 115, and the valve housing hole 115 is divided into three compartments (a high pressure chamber C _H , an intermediate pressure chamber C _M , and a low pressure chamber C _L ) by the spool 71. Sealed. Image between the high pressure chamber C _H is the y-axis negative direction side of the spool 71, middle chamber C _M is y-axis positive side, the low-pressure chamber C _L is an outer peripheral seal portion 71c and the opening portion 71b of the spool 71 Formed in the formed region.

  The valve housing hole 115 is connected to the first fluid pressure chamber A <b> 1 through the oil passage 113 and the through hole 52. The oil passage 113 is an oil passage provided in the first housing 11, and the through hole 52 is a radial through hole provided in the adapter ring 5. The seal portion 71 c in the spool 71 is provided at a position that closes the oil passage 113 when the spring 72 is not contracted.

Therefore, when the spool 71 is moved in the y-axis positive direction is passed through the oil passage 113 and the high pressure chamber C _H is continuous, high pressure is introduced into first fluid pressure chamber A1. When the spool 71 is moved in the y-axis negative direction, the oil passage 113 is low pressure is introduced into first fluid pressure chamber A1 is communicated with the low pressure chamber C _L.

High pressure chamber _{C H} is connected to the discharge port 63, 122 through the oil passage 21 and the pilot orifice 300 from the y-axis negative direction, the low pressure chamber _{C L} connecting the suction port IN through an oil passage 7a. The oil passage 7a is provided in the y-axis positive direction side than the seal portion 71c, it is cut off from the high pressure chamber C _H.

Further, the middle chamber _{C M} is the oil passage 116, connected to the second fluid pressure chamber A2 through the damper orifice 200, the oil passage 7a and the discharge port 63 further through the metering orifice 110 provided to the pressure plate 6 , 122. Thus the pressure in the high pressure chamber C _H and the medium pressure chamber C _M becomes the differential pressure that is proportional to the flow rate of the metering orifice 110, and upstream pressure, and downstream pressure.

[Swing of cam ring]
The control pressure of the control valve 7 is introduced into the first fluid pressure chamber A1 through the oil passages 52 and 113. Further, the downstream pressure of the metering orifice 110 is introduced into the second fluid pressure chamber A2.

Becomes larger the pressure difference of the metering orifice 110 with an increase in discharge pressure, also the pressure difference between the pressure chamber C _M in which is connected to the high pressure chamber C _H and a downstream side connected to the upstream side of the metering orifice 110 growing. This pressure difference, the spool 71 of the control valve 7 is moved in the y-axis positive direction against the biasing force of the spring 72, the first fluid pressure chamber A1 and the high-pressure chamber C _H communicated threaded with the first fluid pressure chamber High pressure Ph is introduced into A1.

  On the other hand, the second fluid pressure chamber A2 communicates with the intermediate pressure chamber CM and the downstream pressure of the metering orifice 110 is introduced, and a differential pressure is generated between the first and second fluid pressure chambers A1 and A2. This differential pressure causes the cam ring 4 to swing in the y-axis negative direction against the biasing force of the spring 91.

Accordingly, the pump chamber By + on the y-axis positive direction side is reduced to reduce the amount of hydraulic oil pushed into the discharge ports 63, 122, and the pump chamber By- on the y-axis negative direction side is enlarged to be the intake port 62, The amount of hydraulic oil returned to 121 increases. Therefore the pump discharge amount is reduced, the differential pressure also decreases the high pressure chamber C _H and the medium pressure chamber C _M differential pressure of the metering orifice 110 is reduced.

Thus the spool 71 is moved in the y-axis negative direction not resist the urging force of the spring 72, the pressure of the first fluid pressure chamber A1 and the high-pressure chamber C _H and is blocked first fluid pressure chamber A1 is lowered. As a result, the differential pressure between the first and second fluid pressure chambers A1 and A2 decreases, the force in the positive y-axis direction due to the differential pressure and the biasing force of the spring 91 balance, and the cam ring 4 stops swinging.

  Thus, the position of the cam ring 4 is adjusted so that the discharge amount is always constant by the differential pressure of the metering orifice 110 and the urging force of the springs 71 and 91. As the opening area of the metering orifice 110 decreases, the differential pressure also increases. When the opening area increases, the differential pressure decreases.

(Relief valve)
The relief valve 80 includes a valve body 81, a valve seat 82, a valve ball 83, and a spring 84. The spring 84 is locked to the bottom 71a of the spool 71 and urges the valve body 81 in the positive y-axis direction. Along with this, the valve body 81 abuts on the valve ball 83, and urges the valve seat 82 to the y axis positive direction side through the valve ball 83.

  Further, the outer periphery of the y-axis positive direction end portion 81a of the valve body 81 is in liquid-tight contact with the inner periphery of the spool 71, and the valve body 81 and the inner periphery of the spool 71 form a first oil chamber D1. A first radial hole 71 d is provided on the outer periphery of the spool 71, and the outer peripheral portion and the inner peripheral portion of the spool 71 communicate with each other.

The first radial hole 71d is positioned in the y-axis negative direction side of the y-axis positive direction end portion 81a of the valve body 81 when the spring 84 of the relief valve 80 is fully extended, the low pressure chamber C _L and the first It communicates with the oil chamber D1. When the valve body 81 moves in the positive y-axis direction, the first radial hole 71d is closed.

The valve seat 82 has a through-hole 82a in the y-axis direction, and the through-hole 82a is closed on the y-axis negative direction side by a valve ball 83 provided between the valve body 81 and the valve seat 82. Y-axis positive direction side of the valve seat 82 faces the middle pressure chamber C _M. The valve seat 82 is also press-fitted and fixed to the inner periphery of the spool 71 on the outer periphery, and a second oil chamber D2 is formed between the valve body 81 and the valve seat 82.

A through-hole 82a in the y-axis direction is provided in the valve seat 82, and an intermediate pressure Pm acts on the valve ball 83 on the negative side in the y-axis direction through the through-hole 82a. When the pressure Pm of medium pressure chamber C _M increases, the valve ball 83 is pressed against the y-axis negative direction against the biasing force of the spring 84, the through hole 82a and the valve ball 83 and the medium pressure chamber C _M diverges The low pressure chamber CL is communicated. As a result, a relief state is reached in which the medium pressure Pm is discharged to the suction port IN through the oil passage 7a.

(Swing of cam ring during relief)
Since the upstream of the middle pressure chamber C _M oil passage 116 and the pilot orifice 200 is provided, the pressure in the middle pressure chamber C _M is reduced at the time of relief. Thus the pressure difference between the high pressure chamber C _H becomes large, the spool 71 moves in the y-axis positive direction against the biasing force of the spring 72.

Therefore the first fluid pressure chamber A1 communicates with the high pressure chamber C _H, the cam ring 4 by the high pressure discharge flow rate swings in the y-axis positive direction side is reduced. Differential pressure of the metering orifice 110 when the discharge flow rate decreases is reduced differential pressure of medium pressure chamber C _M and the high pressure chamber C _H also decreases, the pressure Ph in the high pressure chamber C _H is completely against the biasing force of the spring 72 The spool 71 moves in the negative y-axis direction.

For this reason, the high pressure chamber _CH and the first fluid pressure chamber A1 are shut off, and the pressure of the first fluid pressure chamber A1 decreases. As a result, the force in the positive direction of the y-axis acting on the cam ring 4 from the first fluid pressure chamber A1 is reduced, the swing of the cam ring 4 is stopped, and the discharge flow rate is reduced.

  As a result, the differential pressure across the metering orifice 110 is also reduced, the expansion of the differential pressure is corrected, and the pump discharge flow rate is maintained at a predetermined flow rate. Therefore, in the relief state, the surplus flow rate is reduced by the swinging of the cam ring 4, and the efficiency is improved.

(Metering orifice)
FIG. 3 is an enlarged cross-sectional view in the vicinity of the variable aperture mechanism 100. The metering orifice 110 is a hole that is long in the radial direction of the pump, and the opening area is changed by swinging the cam ring 4 in the y-axis direction.

  The long hole forming the metering orifice 110 has a long axis slightly deviated from the z-axis direction, and a part of the z-axis negative direction side end portion is when the cam ring 4 swings most in the y-axis positive direction. However, it is provided so as not to be blocked by the cam ring 4. Therefore, the metering orifice 110 is always opened to the second fluid pressure chamber A2 by the minimum guaranteed area 111 that is not blocked by the cam ring 4.

  When the cam ring 4 swings in the y-axis positive direction, the cam ring 4 partially closes the opening of the metering orifice 110 to reduce the opening area, and only part of the cam ring 4 moves to the y-axis positive direction side. It is blocked leaving behind. The metering orifice 110 and the cam ring 4 form a variable throttle mechanism 100 that can change the flow path area.

  Since the opening of the metering orifice 110 is provided in a long hole in the circumferential direction, the metering orifice 110 is gradually closed after the cam ring 4 is swung by a predetermined angle. Therefore, the metering orifice 110 is not throttled when the discharge flow rate is constant during non-relief, and the influence on the discharge amount control due to the change in the differential pressure across the metering orifice 110 is suppressed, and the discharge amount control can be easily tuned. To do.

  Further, the opening of the metering orifice 110 is a long hole having a larger circumferential dimension than a radial dimension. Therefore, the area of the metering orifice 110 can be rapidly reduced with respect to the swinging amount of the cam ring 4.

[Supply of pressure oil to the first and second fluid pressure chambers]
Discharge pressure is reduced by the pilot orifice 300 provided on the oil passage 21, is supplied to the high pressure chamber C _H biases the spool 71 in the y-axis positive direction. Thus the spool 71 is passed through the high-pressure chamber C _H and the oil passage 113 are communicated each other by moving in the y-axis positive direction, the pressure Ph in the high pressure chamber C _H is introduced into first fluid pressure chamber A1. The discharge pressure is also introduced into the discharge passage 22 and is throttled by the metering orifice 110 and introduced into the second fluid pressure chamber A2.

Furthermore, since the pressure in the second fluid pressure chamber A2 is supplied to a hydraulic passage provided outside the pump, an orifice differential pressure proportional to the flow rate is generated. Thus, the pressure Pm of chamber C _M in in the orifice downstream is smaller than the pressure Ph in the high pressure chamber C _H in the orifice upstream. As a result, the second fluid pressure chamber A2 has a lower pressure than the first fluid pressure chamber A1, and the cam ring 4 swings in the positive y-axis direction.

  When the cam ring 4 swings, the pump discharge flow rate decreases, the flow rate differential pressure of the metering orifice 110 decreases, the differential pressure between the high pressure chamber CH and the intermediate pressure chamber CM decreases, and the spool 71 is y Move in the axial direction. As a result, the pressure supplied to the first fluid pressure chamber A1 decreases, and the cam ring 4 stops oscillating to a predetermined discharge flow rate.

  The pressure of the first and second fluid pressure chambers A1 and A2 acts on the cam ring 4 from the outer peripheral side, and the discharge pressure acts on the y-axis negative direction side and the z-axis negative direction side from the inner peripheral side. The swing of the cam ring 4 stops at a position where these pressures are balanced.

When the ejection amount is decreased, the pressure difference reduction of the metering orifice 110, the spool 71 is moved in the y-axis negative direction by the urging force of the spring 72 decreases even pressure Ph in the high pressure chamber C _H, the low-pressure chamber CL and oil A path 113 is communicated. As a result, the low pressure Pl is introduced into the first fluid pressure chamber A1, the first fluid pressure chamber A1 becomes lower in pressure than the second fluid pressure chamber A2, and the cam ring 4 returns to the y-axis negative direction side. Therefore, the differential pressure due to the metering orifice 110 becomes constant and becomes a predetermined flow rate.

[Reduction of discharge flow rate during relief]
FIG. 4 is a diagram showing the relationship between the opening area of the metering orifice 110 and the swing amount of the cam ring 4. If the swinging amount of the cam ring 4 is within the normal use range, the metering orifice 110 is not closed by the cam ring 4, and the opening area is constant while being fully opened. The discharge flow rate is maintained at a constant flow rate by the differential pressure of the metering orifice 110, the movement of the spool 71, and the swinging of the cam ring 4.

In a relief state in which the pressure in the middle pressure chamber C _M is discharged to the suction port IN through a relief valve 80 and the oil passage 7a, the pressure of the medium pressure chamber C _M side decreases due to the presence of the oil passage 7a and the pilot orifice 300 To do.

Therefore, next to the pressure Pm of the pressure Ph> medium pressure chamber _{C M} of the high-pressure chamber _{C H,} the pressure P1 of first fluid pressure chamber A1 communicating with the high pressure chamber _{C H} is a second fluid in communication with the middle chamber _{C M} It becomes larger than the pressure P2 of the pressure chamber A2. As a result, the cam ring 4 swings in the positive y-axis direction, and the discharge amount is reduced. In the relief state, the swing amount of the cam ring 4 is further increased as described above.

Here, when the cam ring 4 moves in the positive y-axis direction, the opening area of the metering orifice 110 decreases. Differential pressure when the opening area of the metering orifice 110 is reduced also increases, the greater the pressure difference of the medium pressure chamber C _M and the high pressure chamber C _H accordingly. Therefore, the spool 71 moves in the positive y-axis direction, the high-pressure chamber CH and the first fluid pressure chamber A1 communicate with each other, the first fluid pressure chamber A1 becomes high pressure, and the cam ring 4 further swings in the y-axis positive direction. The discharge flow rate is further reduced.

Thus squeezing the flow rate of the medium-pressure chamber C _M during the relief, the excess amount of oil reduces with reduced working oil discharge amount when the relief that is discharged from the intermediate pressure chamber C _M to the suction port IN, improved fuel economy Let

  Further, by changing the flow passage cross-sectional area (the opening area of the metering orifice 110) by swinging the cam ring 4 and reducing the hydraulic oil discharge amount, the hydraulic oil discharge amount and the flow passage cross-sectional area change can be linked with a simple configuration. Is.

  In addition, since the cam ring 4 is easily moved in the positive y-axis direction by the pilot orifice 300, the opening area of the metering orifice 110 is easily reduced, and the amount of hydraulic oil discharged during relief is further reduced. The relief state can be accurately determined by the movement of the cam ring 4 in the positive y-axis direction at that time.

Here, the pressure Pm of medium pressure chamber C _M when relief if throttled pilot orifice 300 becomes more likely to decrease, there is also possible to reduce the surplus flow rate by increasing the amount of swing correspondingly cam ring 4. However, varies the pressure Pm of medium pressure chamber C _M by vibration of the valve ball 83 during the relief, the spool 71 and the cam ring 4 also there is a possibility that the vibration of the vibration to the discharge pressure is generated.

  Therefore, in this application, since the metering orifice 110 is configured to be throttled at the time of relief, the throttle at the pilot orifice 300 can be set relatively gently, and the excess flow rate can be reduced without causing hydraulic vibration. is there.

  Further, by providing the damper orifice 200, the vibration of the spool 71 due to the discharge pressure is suppressed, the hydraulic vibration is suppressed even during relief, the control valve 7 is stably operated, and the swing of the cam ring 4 is stabilized. .

[Effect of Example 1]
(1) (15) and the metering orifice 110 provided in the discharge discharge passage 22 connected to the port 63, 122, a high pressure chamber _{C H} the upstream pressure of the metering orifice 110 is introduced, the downstream pressure a pressure chamber C _M in introduced, anda low pressure chamber C _L is connected to the reservoir tank RSV which stores hydraulic oil, the pressure is introduced into first fluid pressure chamber A1 and second fluid pressure chamber A2 Is provided between the control valve 7 for controlling the pressure and the downstream side of the metering orifice 110 and the reservoir tank RSV, and opens when the pressure is higher than a predetermined pressure, and discharges the pressure downstream of the metering orifice 110 to the reservoir tank RSV side. And a variable throttle mechanism 100 that throttles the cross-sectional area of the metering orifice 110 when at least the relief valve 80 is opened. It decided to.

Thus squeezing the flow rate by the metering orifice 110 at the time of relief, to oscillate the cam ring 4 becomes possible to reduce the surplus oil amount discharged to the suction port IN from the intermediate pressure chamber C _M and generates a hydraulic vibration Therefore, the surplus flow rate can be stably reduced.

  (2) (16) The variable throttle mechanism 100 includes the metering orifice 110 and the cam ring 4 that gradually blocks the opening by swinging, and the metering orifice 110 is the first plate or the second plate. It was decided to have an opening at the axial end face. Thereby, the reduction | decrease of discharge flow volume and the change of the flow-path cross-sectional area at the time of relief can be linked. In addition, the configuration can be simplified.

  (3) (17) The variable throttle mechanism 100 gradually closes the opening of the metering orifice 110 after the cam ring 4 swings by a predetermined angle. Since the metering orifice 110 is not throttled when the discharge amount is reduced during non-relief, the influence on the discharge amount control due to the change in the differential pressure across the metering orifice 110 is suppressed, and the tuning of the discharge amount control is facilitated. can do.

  (4) The opening of the metering orifice 110 has a larger circumferential dimension than a radial dimension. Thereby, the area of the metering orifice 110 can be rapidly reduced with respect to the swinging amount of the cam ring 4, and the excess flow rate can be greatly reduced.

  (5) The opening of the metering orifice 110 has an elliptical or long hole shape. Thereby, the same effect as said (4) can be acquired.

(7) (18) was further having a pilot orifice 300 provided in the passage connecting the discharge port 63, 122 and the high pressure chamber _{C H.} Thereby, the relief state can be accurately determined based on the swing of the cam ring 4.

(8) was further having a damper orifice 200 provided in a passage connecting the middle pressure chamber C _M and the metering orifice 110. Thereby, the stability of the control valve 7 at the time of relief can be improved.

The following is a modification of the first embodiment.
[Example 1-1]
5 and 6 are examples in which the minimum guaranteed area 111 of the metering orifice 110 is a separate hole. In the first embodiment, the major axis of the metering orifice 110 is deviated from the z axis. However, in the first embodiment 1-1, a long hole having a major axis parallel to the z axis is used. It is formed by a hole separately provided on the y-axis positive direction side.

  The metering orifice 110 is completely closed at the position where the cam ring 4 is swung most in the positive direction of the y-axis (two-dot chain line), but the minimum guaranteed area 111 is provided at a position where it is not closed regardless of the position of the cam ring 4. Yes. For this reason, the major axis of the metering orifice 110 can be made parallel to the z-axis to simplify the processing.

[Example 1-2]
(6) FIG. 7 shows an example in which the metering orifice 110 is formed by a plurality of round holes. Thereby, the rigidity around the opening of the metering orifice 110 can be ensured while ensuring a sufficient opening area.

[Example 1-3]
FIG. 8 shows an example in which the damper orifice 200 is provided outside the adapter ring 5 in Example 1-1. An oil passage 23 that connects the middle pressure chamber _{C M} and the second fluid pressure chamber A2 outside the first housing 11 is provided, providing the damper orifice 200 into the oil passage 23.

[Example 1-4]
FIG. 9 shows an example in which a piston 92 that moves forward and backward by swinging of the cam ring 4 is provided, and a metering orifice 110 is provided in the piston 92. The piston 92 is a bottomed cylindrical member that is provided on the y-axis negative direction side of the plug member 90 and on the y-axis positive direction side of the cam ring 4 and makes the bottom portion contact the cam ring 4 with the y-axis positive direction side facing.

  The outer periphery of the piston 92 is slidably inserted into the plug member insertion hole 114 while maintaining liquid tightness, and the plug member 90 and the piston 92 form a third oil chamber D3. The opening 22a of the discharge passage 22 connected to the discharge ports 63 and 122 is provided on the inner periphery of the plug member 90. By introducing discharge pressure into the third oil chamber D3, the piston 92 together with the spring 91 is moved along the y axis. Energize in the negative direction. As a result, the cam ring 4 is urged in the y-axis negative direction via the piston 92 by the urging force of the spring 91 and the pressure of the third oil chamber D3.

  The cylindrical portion of the piston 92 is provided with a small hole communicating the inner peripheral side and the outer peripheral side, and this small hole is used as the metering orifice 110. The piston 92 is pressed in the positive y-axis direction by the cam ring 4 as it swings in the positive y-axis direction, and moves in the positive y-axis direction against the pressure of the spring 91 and the third oil chamber D3.

  When the piston 92 moves in the positive y-axis direction, the piston 92 is immersed in the plug member insertion hole 114, and the metering orifice 110 is closed by the plug member insertion hole 114. Thus, the variable aperture mechanism 100 is configured. As in the first embodiment, the amount of hydraulic oil discharged during relief is reduced. Further, since the plug member insertion hole 114 closes the leakage at the metering orifice 110, the accuracy of the throttle amount control is improved.

  (9) It is further provided with a piston that moves forward and backward as the cam ring 4 swings, and the variable throttle mechanism 100 is provided on the piston. Thereby, the leak in the metering orifice 110 becomes small, and the precision of throttle amount control can be improved.

  Example 2 will be described. The basic configuration is the same as that of the first embodiment. In the first embodiment, the opening provided in the discharge passage 22 is used as the metering orifice 110. However, the second embodiment is different in that the metering orifice 110 is formed using a spool 400 that changes the flow path area.

  FIG. 10 is an axial sectional view of the vane pump 1 in the second embodiment, and FIG. 11 is a radial sectional view. In FIG. 11, since the cross section is different from the radial direction sectional view of the first embodiment (FIG. 2), only a part of the control valve 7 is shown. A spool housing hole 117 is provided in the first housing 11 in parallel with the valve housing hole 115 for the control valve 7, and the spool 400 is housed therein.

  The spool 400 has step portions 423 and 425 at both ends in the y-axis direction, and has a concave portion 424 formed over the entire circumference at a substantially central portion. Further, seal portions 421-322 are provided on both sides of the concave portion 424 in the y-axis direction so that the spool receiving holes 117 are liquid-tight into three sections (first, second, third spool oil chambers 411, 412, 413). To seal.

The first spool oil chamber 411 is provided with a spring 401 and is engaged with the y-axis negative direction side step portion 423 of the spool 400. The spring 401 is locked to the end of the spool receiving hole 117 in the negative y-axis direction and biases the spool 400 in the positive y-axis direction. Further, the first spool fluid chamber 411 suction pressure is introduced to connect the suction port IN, it is connected to the pressure chamber C _M in the control valve 7 by the oil passage 7a.

The second spool oil chamber 412 and the third spool oil chamber 413 are connected to the discharge port OUT, and a discharge pressure is introduced to bias the spool 400 in the positive y-axis direction. Discharge port OUT are connected by an oil passage of the discharge port 63, 122 and medium pressure chamber _{C M} and not shown.

  The second fluid pressure chamber A <b> 2 is connected to the spool receiving hole 117 through the oil passage 24. The opening 24a of the oil passage 24 is provided so that the concave portion 424 and the y-axis direction position overlap in a normal state where no differential pressure is applied to the spool 400. Therefore, in the normal state, the oil passage 24 is connected to the discharge port OUT via the recess 424.

When the discharge pressure increases and reaches the relief pressure, the spool 400 moves in the positive y-axis direction against the urging force of the spring 401, so that the opening 24 a moves to the y-axis positive direction seal portion 422 of the spool 400. It is gradually blocked. Accordingly, the flow path area between the second fluid pressure chamber A2 and the discharge port OUT is reduced (corresponding to the restriction of the metering orifice 110 of the first embodiment), and thereby a differential pressure is generated between the second fluid pressure chamber A2 and the discharge port OUT. To do. The differential pressure control valve 7 is moved by the pressure Ph in the high pressure chamber C _H is introduced into first fluid pressure chamber A1.

  As a result, the cam ring 4 swings in the positive y-axis direction, and the discharge amount and the discharge pressure are reduced. As in the first embodiment, the surplus discharge pressure during relief is reduced. The variable throttle mechanism 100 is configured with a simple configuration by adjusting the biasing force of the spring 401 and setting so that the opening 24a is closed when the discharge pressure becomes a predetermined value or more. In addition, the excess flow is reliably reduced by the relief pressure.

[Effect of Example 2]
(12) (19) The discharge port 63, 122 has a variable throttle mechanism 100 that throttles the cross-sectional area of the metering orifice 110 when the discharge pressure downstream of the discharge ports 63, 122 is equal to or higher than a predetermined pressure. Thereby, the same effect as Example 1 can be acquired.

  (14) The variable aperture mechanism 100 is configured by the spool 400 that variably controls the opening area by advancing and retracting. Thereby, the variable aperture mechanism 100 can be configured with a simple configuration.

The following is a modification of the second embodiment.
[Example 2-1]
FIG. 12 shows an example in which the spool 400 is an electromagnetic valve. The spool 400 of the second embodiment is a mechanical valve that moves according to the discharge pressure. However, in the embodiment 2-1, the electromagnetic actuator 500 is connected to the spool 400 and the detected value of the pressure sensor 510 that detects the pressure of the discharge port OUT is used. Based on this, the electromagnetic actuator 500 is driven to close the opening 24a, and the metering orifice 110 and the variable throttle mechanism 100 are configured.

[Effect of Example 2-1]
(13) (20) The variable throttle mechanism 100 is composed of a hydraulic sensor that detects the discharge pressure and an electromagnetic valve that opens based on an output signal of the hydraulic sensor. The degree of freedom in design and tuning accuracy can be increased by moving the spool 400 electromagnetically to change the flow path area.

[Example 2-2]
FIG. 13 is an example in which the relief valve 80 is provided outside the housing 11 in the embodiment 2-1. Relief valve 80 as well as connected to a second spool fluid chamber 412 and the medium pressure chamber _{C M} of the spool 400 by the oil passage 27, connected to the reservoir tank RSV. The relief valve 80 allows only the flow from the oil passage 27 to the reservoir tank RSV side.

  The second spool oil chamber 412 of the spool 400 is connected to the discharge ports 63 and 122 by the oil passage 26. The first spool oil chamber 411 is connected to the suction port IN via the oil passage 28.

Relief valve 80 provided outside of the control valve 7, and because the orifice between the middle pressure chamber C _M and the oil passage 27 is not provided, the pressure in the middle pressure chamber C _M when relief without lowered, The swing of the cam ring 4 is suppressed.

  In Example 2-2, when the detected value of the pressure sensor 510 reaches the relief pressure, the solenoid valve 500 is driven, and the spool 400 is moved to narrow the oil passage 27 (corresponding to the metering orifice 110 of Example 1). The surplus flow rate is reduced by swinging the cam ring 4. Therefore, it is not necessary to operate the control valve 7 using the discharge pressure at the time of relief, and the problem of vibration of the control valve 7 is also avoided.

[Example 2-3]
FIGS. 14 and 15 are examples in which the shape of the spool 400 is changed and the spool 400 is operated by the discharge pressure downstream of the relief valve 80. In Example 2-3, the oil path 30 is provided on the negative side of the spool 400 in the y-axis direction, and the oil path 30 is connected to the downstream side of the relief valve 80. The spring 401 is provided in the third spool oil chamber 413 and biases the spool 400 in the negative y-axis direction.

  The spool 400 of the embodiment 2-3 is provided with a fourth spool oil chamber 414 in addition to the first to third spool oil chambers 411 to 413. Accordingly, the volume of the first spool oil chamber 411 is reduced as compared with the second embodiment.

  The fourth spool oil chamber 414 is provided between the first and second spool oil chambers 411-312 and is connected to the suction port IN via the oil passage 29. The fourth spool oil chamber 414 is connected to the third spool oil chamber 413 through an axial hole 430 provided in the central axis of the spool 400, and introduces suction pressure into the third spool oil chamber 413.

  As a result, when the downstream pressure of the relief valve 80 increases, the spool 400 moves in the positive y-axis direction against the biasing force, and the opening area of the opening 24a of the oil passage 24 is reduced. Therefore, similarly to the second embodiment, the excessive discharge pressure at the time of relief is reduced, and the variable throttle mechanism 100 is configured with a simple configuration. Further, by driving the spool 400 using the pressure on the downstream side of the relief valve 80, the relief state can be grasped more accurately.

[Effect of Example 2-3]
(10) The variable throttle mechanism 100 changes the flow path area based on the pressure downstream of the relief valve 80. Thereby, the relief state can be grasped more accurately.

  (11) The variable aperture mechanism 100 is configured by the spool 400 that variably controls the opening area by advancing and retreating. The variable aperture mechanism 100 can be configured with a simple configuration.

[Other embodiments]
The best mode for carrying out the present invention has been described based on each embodiment, but the specific configuration of the present invention is not limited to each embodiment and does not depart from the gist of the invention. Such design changes are included in the present invention.

It is an axial sectional view of a vane pump in Example 1. It is radial direction sectional drawing (at the time of the largest rocking | fluctuation) of the vane pump in Example 1. FIG. 3 is an enlarged cross-sectional view of the vicinity of a variable aperture mechanism 100. FIG. FIG. 6 is a diagram showing the relationship between the opening area of the metering orifice 110 and the swing amount of the cam ring 4. In this example, the minimum guaranteed area 111 of the metering orifice 110 is a separate hole. FIG. 6 is an enlarged view of FIG. 5. This is an example in which the metering orifice 110 is formed by a plurality of round holes. In this example, the damper orifice 200 is provided outside the first housing 11. This is an example in which a metering orifice 110 is provided in a piston 92 that moves forward and backward by swinging of the cam ring 4. FIG. 5 is an axial cross-sectional view of a vane pump 1 in Embodiment 2. 6 is a radial cross-sectional view of a vane pump 1 in Embodiment 2. FIG. In this embodiment, the spool 400 is an electromagnetic valve. In this example, the relief valve 80 is provided outside the housing 11 in Example 2-1. In the second embodiment, the spool 400 is operated by the suction pressure downstream of the relief valve 80. It is an enlarged view of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Variable displacement type vane pump 2 Drive shaft 3 Rotor 4 Cam ring 5 Adapter ring 6 Pressure plate 7 Control valve 10 Pump body 11, 12 1st, 2nd housing 11a Bottom part 11b Pump element accommodating part 21, 23 Oil path 22 Discharge path 22a Opening Portion 24 Oil passage 24a Opening portion 26-30 Oil passage 31 Slot 32 Vane 33 Back pressure chamber 40 Pin 50 Seal member 52 Through hole 62, 121 Suction port 63, 122 Discharge port 71 Spool 71a Bottom portion 71b Opening portion 71c Seal portion 71d Diameter Direction hole 71e Radial hole 80 Relief valve 81 Valve body 82 Valve seat 82a Through hole 83 Valve ball 90 Plug member 92 Piston 100 Variable throttle mechanism 110 Metering orifice 111 Minimum guaranteed area 113 Oil passage 115 Valve housing hole 116 Oil passage 117 Spool storage 120 X-axis negative side surface 200 Damper orifice 300 Pilot orifice 400 Spool 411-312, 413 Spool oil chamber 414 Spool oil chamber 421-322 Seal portion 423, 425 Step portion 424 Recess 430 Shaft core hole 500 Electromagnetic actuator 510 Pressure sensor A 1 A2 First and second fluid pressure chambers B Pump chamber C _H High pressure chamber C _M Medium pressure chamber C _L Low pressure chamber IN Suction port RSV Reservoir tank

Claims (20)

A pump body;
A drive shaft supported by the pump body;
A rotor provided in the pump body and driven to rotate by the drive shaft;
Vanes accommodated in a slot provided in the circumferential direction of the rotor so as to freely appear and disappear;
A cam ring that is eccentrically provided in the pump body, is formed in an annular shape, and forms a plurality of pump chambers together with the rotor and the vane on the inner peripheral side;
A first plate member and a second plate member provided on both axial sides of the cam ring;
A suction port that is provided on at least one side of the first plate member or the second plate member and opens to a region where the volumes of the plurality of pump chambers increase, and a direction in which the volumes of the plurality of pump chambers decrease. A discharge port that opens to
A first fluid pressure chamber provided on an outer peripheral side of the cam ring, and an outer peripheral side space of the cam ring provided on a side on which a discharge amount increases; and a second fluid pressure chamber provided on a side on which the discharge amount decreases. A seal member defined in
A metering orifice provided in a discharge passage connected to the discharge port;
A high-pressure chamber into which upstream pressure of the metering orifice is introduced; an intermediate-pressure chamber into which downstream pressure is introduced; and a low-pressure chamber connected to a reservoir tank that stores hydraulic oil. Pressure control means for controlling the pressure introduced into the fluid pressure chamber or the second fluid pressure chamber;
A relief valve that is provided between the downstream side of the metering orifice and the reservoir tank, opens when the pressure is equal to or higher than a predetermined pressure, and discharges the pressure downstream of the metering orifice to the reservoir tank side;
A variable displacement vane pump, comprising: a variable throttle mechanism that throttles a cross-sectional area of the metering orifice when at least the relief valve is opened. The variable displacement vane pump according to claim 1,
The variable throttle mechanism is composed of the cam ring that gradually blocks the opening by swinging the metering orifice,
The metering orifice has an opening in an axial end surface of the first plate or the second plate. The variable displacement vane pump according to claim 2,
The variable throttle vane pump characterized in that the variable throttle mechanism gradually closes the opening after the cam ring swings by a predetermined angle. The variable displacement vane pump according to claim 2,
The variable displacement vane pump, wherein the opening of the metering orifice has a circumferential dimension larger than a radial dimension. The variable displacement vane pump according to claim 4,
The variable displacement vane pump characterized in that the opening of the metering orifice has an elliptical or long hole shape. The variable displacement vane pump according to claim 4,
The variable displacement vane pump, wherein the opening of the metering orifice is formed by a plurality of holes. The variable displacement vane pump according to claim 2,
A variable displacement vane pump, further comprising a pilot orifice provided in a passage connecting the discharge port and the high pressure chamber. The variable displacement vane pump according to claim 2,
A variable displacement vane pump, further comprising a damper orifice provided in a passage connecting the metering orifice and the intermediate pressure chamber. The variable displacement vane pump according to claim 1,
A piston that moves forward and backward by swinging the cam ring;
The variable displacement vane pump, wherein the variable throttle mechanism is provided in the piston. The variable displacement vane pump according to claim 1,
The variable displacement vane pump, wherein the variable throttle mechanism changes a flow path area based on a pressure downstream of the relief valve. The variable displacement vane pump according to claim 10,
The variable throttle mechanism includes a spool that variably controls an opening area by advancing and retreating. A pump body;
A drive shaft supported by the pump body;
A rotor provided in the pump body and driven to rotate by the drive shaft;
Vanes accommodated in a slot provided in the circumferential direction of the rotor so as to freely appear and disappear;
A cam ring that is eccentrically provided in the pump body, is formed in an annular shape, and forms a plurality of pump chambers together with the rotor and the vane on the inner peripheral side;
A first plate member and a second plate member provided on both axial sides of the cam ring;
A suction port that is provided on at least one side of the first plate member or the second plate member and opens to a region where the volumes of the plurality of pump chambers increase, and a direction in which the volumes of the plurality of pump chambers decrease. A discharge port that opens to
A first fluid pressure chamber provided on an outer peripheral side of the cam ring, and an outer peripheral side space of the cam ring provided on a side on which a discharge amount increases; and a second fluid pressure chamber provided on a side on which the discharge amount decreases. A seal member defined in
A metering orifice provided in a discharge passage connected to the discharge port;
A high-pressure chamber into which upstream pressure of the metering orifice is introduced; an intermediate-pressure chamber into which downstream pressure is introduced; and a low-pressure chamber connected to a reservoir tank that stores hydraulic oil. Pressure control means for controlling the pressure introduced into the fluid pressure chamber or the second fluid pressure chamber;
A relief valve that is provided between the downstream side of the metering orifice and the reservoir tank, opens when the pressure is equal to or higher than a predetermined pressure, and discharges the pressure downstream of the metering orifice to the reservoir tank side;
A variable displacement vane pump, comprising: a variable throttle mechanism that throttles a cross-sectional area of the metering orifice when a discharge pressure downstream of the discharge port is equal to or higher than a predetermined pressure. The variable displacement vane pump according to claim 12,
The variable throttle mechanism includes a hydraulic sensor that detects a discharge pressure and an electromagnetic valve that opens based on an output signal of the hydraulic sensor. The variable displacement vane pump according to claim 12,
The variable throttle mechanism includes a spool that variably controls an opening area by advancing and retreating. A pump body;
A drive shaft supported by the pump body;
A rotor provided in the pump body and driven to rotate by the drive shaft;
Vanes accommodated in a slot provided in the circumferential direction of the rotor so as to freely appear and disappear;
A cam ring that is eccentrically provided in the pump body, is formed in an annular shape, and forms a plurality of pump chambers together with the rotor and the vane on the inner peripheral side;
A first plate member and a second plate member provided on both axial sides of the cam ring;
A suction port that is provided on at least one side of the first plate member or the second plate member and opens to a region where the volumes of the plurality of pump chambers increase, and a direction in which the volumes of the plurality of pump chambers decrease. A discharge port that opens to
A first fluid pressure chamber provided on an outer peripheral side of the cam ring, and an outer peripheral side space of the cam ring provided on a side on which a discharge amount increases; and a second fluid pressure chamber provided on a side on which the discharge amount decreases. A seal member defined in
A metering orifice provided in a discharge passage connected to the discharge port;
A high-pressure chamber into which upstream pressure of the metering orifice is introduced; an intermediate-pressure chamber into which downstream pressure is introduced; and a low-pressure chamber connected to a reservoir tank that stores hydraulic oil. Pressure control means for controlling the pressure introduced into the fluid pressure chamber or the second fluid pressure chamber;
A relief valve that is provided between the downstream side of the metering orifice and the reservoir tank, opens when the pressure is equal to or higher than a predetermined pressure, and discharges the pressure downstream of the metering orifice to the reservoir tank side;
A variable displacement vane pump, comprising: a variable throttle mechanism that throttles a cross-sectional area of the metering orifice as the amount of eccentricity of the cam ring decreases when the relief valve is opened. The variable displacement vane pump according to claim 15,
The variable throttle mechanism is composed of the metering orifice and the cam ring that gradually blocks the opening by swinging,
The metering orifice has an opening in an axial end surface of the first plate or the second plate. The variable displacement vane pump according to claim 15,
The variable displacement vane pump, wherein the variable throttle mechanism gradually blocks the opening after the cam ring moves by a predetermined angle. The variable displacement vane pump according to claim 15,
A variable displacement vane pump, further comprising a pilot orifice provided in a passage connecting the discharge port and the high pressure chamber. A pump body;
A drive shaft supported by the pump body;
A rotor provided in the pump body and driven to rotate by the drive shaft;
Vanes accommodated in a slot provided in the circumferential direction of the rotor so as to freely appear and disappear;
A cam ring that is eccentrically provided in the pump body, is formed in an annular shape, and forms a plurality of pump chambers together with the rotor and the vane on the inner peripheral side;
A first plate member and a second plate member provided on both axial sides of the cam ring;
A suction port that is provided on at least one side of the first plate member or the second plate member and opens to a region where the volumes of the plurality of pump chambers increase, and a direction in which the volumes of the plurality of pump chambers decrease. A discharge port that opens to
A first fluid pressure chamber provided on an outer peripheral side of the cam ring, and an outer peripheral side space of the cam ring provided on a side on which a discharge amount increases; and a second fluid pressure chamber provided on a side on which the discharge amount decreases. A seal member defined in
A metering orifice provided in a discharge passage connected to the discharge port;
A high-pressure chamber into which upstream pressure of the metering orifice is introduced; an intermediate-pressure chamber into which downstream pressure is introduced; and a low-pressure chamber connected to a reservoir tank that stores hydraulic oil. Pressure control means for controlling the pressure introduced into the fluid pressure chamber or the second fluid pressure chamber;
A hydraulic sensor for detecting the discharge pressure;
A pressure utilization device that utilizes the pressure supplied from the discharge port, and a relief valve that discharges the pressure downstream of the metering orifice to the reservoir tank side;
A variable displacement vane pump comprising: a variable throttle mechanism that throttles a cross-sectional area of the metering orifice based on an output signal of the hydraulic sensor. The variable displacement vane pump according to claim 19,
The variable displacement vane pump, wherein the variable throttle mechanism is an electromagnetic valve that opens based on an output signal of the hydraulic sensor.

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