JP2013194692A - Variable displacement vane pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a variable displacement vane pump that can suppress retention of hydraulic oil in a land part of a spool, and preventing retention of foreign matter in the vicinity of the land part.SOLUTION: Between a small-diameter part and a land part of a spool, a tapered part formed to gradually increase a diameter toward the land part from the small-diameter part is formed, and the tapered part is formed in a range at least not smaller than 50% when the height of the land part with respect to the small-diameter part is assumed to be 100%.

Description

  The present invention relates to a variable displacement vane pump.

  As this type of technology, the technology described in Patent Document 1 below is disclosed. Japanese Patent Application Laid-Open No. H10-228667 discloses a control valve spool and a relief valve that are housed in a control valve housing hole formed in the main body of the vane pump.

JP 2010-001773 A

In the vane pump described in Patent Document 1, a land portion that adjusts the opening degree of the opening on the control valve housing hole side of the communication path that communicates the control valve housing hole and the first fluid pressure chamber is provided on the outer periphery of the spool. Is provided. The surface of the land portion extending in the spool radial direction is formed perpendicular to the axial direction of the control valve housing hole. Therefore, the hydraulic oil stays in the land portion, and foreign matter mixed in the hydraulic oil may stay in the vicinity of the land portion.
The present invention pays attention to the above-mentioned problem, and the object of the present invention is a variable capacity capable of suppressing the retention of hydraulic oil in the land portion of the spool and suppressing the retention of foreign matter near the land portion. A mold vane pump is provided.

  In order to achieve the above object, in the variable displacement vane pump of the present invention, a tapered portion formed so that the diameter gradually increases from the small diameter portion toward the land portion between the small diameter portion and the land portion of the spool. The tapered portion is formed in a range of at least 50 percent when the height of the land portion with respect to the small diameter portion is 100 percent.

  Therefore, it is possible to suppress stagnation of foreign matter near the land portion.

1 is an axial sectional view of a variable displacement vane pump according to Embodiment 1. FIG. 1 is a radial cross-sectional view of a variable displacement vane pump of Example 1. FIG. FIG. 3 is an enlarged view of a spool according to the first embodiment. FIG. 3 is an enlarged view of a spool according to the first embodiment.

[Example 1]
[Outline of vane pump]
1 is an axial sectional view of the variable displacement vane pump 1 according to the first embodiment (II sectional view of FIG. 2), and FIG. 2 is a radial sectional view of the variable displacement vane pump 1 (cross section II-II of FIG. 1). Figure). FIG. 2 shows the case where the cam ring 4 is located in the most negative y-axis direction (maximum eccentricity).
The variable displacement vane pump 1 according to the first embodiment supplies hydraulic oil to a power steering device mounted on a vehicle, and a drive shaft 2 is connected to a pulley 9 driven via a belt or the like to an engine not shown in the drawing. Has been. The cross-sectional view of FIG. 2 schematically shows the oil passage configuration and the like in order to simplify the description of the pump function. The axial direction of the drive shaft 2 is the x-axis, and the direction in which the drive shaft is inserted into the pump body 10 is the positive direction. In addition, the axial direction of the cam spring 201 (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 negative y-axis direction and the axis that is orthogonal to the x and y axes, and the suction passage The IN side is the z-axis positive direction. The vane pump according to the first embodiment increases the working oil sucked from the reservoir tank RES to a necessary pressure and supplies a necessary flow rate to the power steering apparatus.
The variable displacement 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 9 and is rotatably supported by the pump body 10. The rotor 3 is a rotating body that is rotationally driven by a drive shaft, and a plurality of slits 31 that are axial grooves are formed radially on the outer periphery of the rotor 3. A plate-like vane 32 having substantially the same length in the x-axis direction as the rotor 3 is inserted into each slit 31 so as to be able to advance and retract in the radial direction. Further, a back pressure chamber 33 is provided at the inner diameter side end portion of each slit 31, and hydraulic oil is supplied to bias the vane 32 radially outward.

  The pump body 10 is formed from a front body 11 and a rear body 12. The front body 11 has a bottomed cup shape that opens in the positive x-axis direction, and a disk-shaped pressure plate 6 is accommodated in the bottom 111. The front body 11 and the rear body 12 are fastened and fixed by a plurality of bolts. A pump element accommodating portion 112 is formed in a space defined by the inner peripheral portion of the front body 11 and the side surface of the rear body 12. The adapter ring 5, the cam ring 4, and the rotor 3 are accommodated in the pump element accommodating portion 112 and on the positive side of the pressure plate 6 in the x-axis direction. The rear body 12 is in liquid-tight contact with the adapter ring 5, the cam ring 4, and the rotor 3 from the x-axis positive direction side, and the adapter ring 5, the cam ring 4, and the rotor 3 are held between the pressure plate 6 and the rear body 12.

  The adapter ring 5 is an annular member that is provided in the pump element accommodating portion 112 that is a cylindrical portion, and in which a cam ring accommodating portion 54 (accommodating space) is formed. The shape of the adapter ring 5 is not limited to the ring shape, and may be formed in a C shape as long as it has at least an arc-shaped portion so that an accommodation space is formed inside. A radial through hole 51 is provided at the end of the adapter ring 5 in the positive y-axis direction. Further, a plug member insertion hole 114 is provided at the end of the front body 11 in the positive y-axis direction, and a bottomed cup-shaped plug member 70 is inserted to ensure liquid-tightness between the front body 11 and the outside. A cam spring 201 is inserted into the inner periphery of the plug member 70 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 contacts the cam ring 4, and is biased in the negative y-axis direction. . The cam spring 201 urges the cam ring 4 in the direction in which the swing amount becomes maximum, and stabilizes the discharge amount (cam ring swing position) at the time of pump start when the pressure is not stable.

A cam ring housing portion 54 is formed inside the adapter ring 5. The cam ring housing portion 54 has a cam ring 4 provided so as to be movable with respect to the drive shaft 2, and forms a plurality of pump chambers 13 together with the rotor 3 and the vanes 32. The cam ring 4 is an annular member that is movably provided in the cam ring housing portion 54 of the adapter ring 5 and has an axial length that is shorter than the axial length of the adapter ring 5.
A pin 40 a is provided between the adapter ring 5 and the cam ring 4. This pin 40a prevents the adapter ring 5 from rotating in the front body 11 when the pump is driven. The cam ring 4 is provided so as to be swingable in the y-axis direction around the pin 40a.
A seal member 50 is provided at the z-axis positive end of the adapter ring inner peripheral surface 53, a support surface N is formed at the z-axis negative end, and a support plate 40 is provided at the support surface N. . The support plate 40 and the seal member 50 define a first fluid pressure chamber A1 and a second fluid pressure chamber A2 between the cam ring 4 and the adapter ring 5. The first fluid pressure chamber A1 is provided in the cam ring accommodating portion 54 and on the outer peripheral side of the cam ring 4, and the internal volume decreases when the cam ring 4 moves in the direction in which the volumes of the plurality of pump chambers 13 increase. Is formed. The second fluid pressure chamber A2 is provided in the cam ring housing portion 54 and on the outer peripheral side of the cam ring 4, and the internal volume increases when the cam ring 4 moves in the direction in which the volumes of the plurality of pump chambers 13 increase. Is formed.
A through hole 52 is provided on the z-axis positive direction side of the adapter ring 5 and on the y-axis negative direction side of the seal member 50. Each of the through holes 52 communicates with the spool 70 via a control pressure oil passage 113 provided in the front body 11, and connects the first fluid pressure chamber A1 on the negative side in the y-axis and the spool 70.

(Configuration of front body)
The front body 11 is formed with a shaft support portion 117 that supports the drive shaft 2. The shaft support 117 is formed through the bottom 111. An oil seal 2a is provided at the end of the shaft support 117 on the pulley 9 side to ensure liquid tightness in the vane pump. A control valve housing hole 116 for accommodating a spool 70 which is a pressure control means for controlling the amount of eccentricity of the cam ring 4 by controlling the pressure in the first fluid pressure chamber A1 on the z axis positive direction side of the front body 11; And a control valve suction oil passage 115 for introducing hydraulic oil from the suction passage IN into the spool 70 and a control pressure oil passage 113 for discharging the control pressure into the first fluid pressure chamber A1.
In addition, the bottom 111 is formed to be recessed at a position facing the second discharge port 63 and a suction groove 111b formed at a position facing the second suction port 62 of the pressure plate 6 to be described later. It has a discharge groove 111a and a discharge passage 20 that is connected to the discharge groove 111a and sends hydraulic oil to the power steering device. A lubricating oil path 118 is formed in the suction groove 111b obliquely with respect to the x axis, and supplies lubricating oil to the oil seal 2a.
(Configuration of pressure plate)
The pressure plate 6 is provided in the pump element accommodating portion 112 that is a cylindrical portion, and is disposed between the adapter ring 5 and the bottom portion 111. The pressure plate 6 is a hole formed so that the drive shaft 2 can pass through the x-axis positive side surface 61 that is a contact portion that contacts the end surface of the adapter ring 5 on one side in the axial direction. A through-hole 66 is formed so as to be movable relative to the shaft 2 in the axial direction. The side surface 61 of the pressure plate 6 on the x-axis positive direction side has a second suction port 62 arranged in an arc shape on the z-axis positive direction side and a second discharge port 63 arranged in an arc shape on the z-axis negative direction side. In addition, a suction-side back pressure groove 64 and a discharge-side back pressure groove 65 for introducing discharge pressure into the back pressure chamber 33 are formed.
The second suction port 62 is disposed so as to face one end surface of the cam ring 4 in the axial direction, and is formed so as to open to a suction region in which the volumes of the plurality of pump chambers 13 increase as the drive shaft 2 rotates. . Further, the pressure plate 6 is biased toward the adapter ring 5 by the pressure supplied from the discharge region acting on the side surface 67 in the negative x-axis direction.

(Rear body configuration)
In the rear body 12, a suction passage 12a is formed in the z-axis direction for introducing the hydraulic oil from a reservoir tank RES that stores the hydraulic oil to the first suction port 122. An oil passage 12d for supplying hydraulic oil to the spool 70 is formed on the positive side of the suction passage 12a in the z-axis direction. A bottomed shaft support portion 12c that supports the drive shaft 2 is formed at a substantially central portion of the rear body 12. A lubricating oil passage 12b communicating with the shaft support portion 12c is formed at the lower end of the suction passage 12a to ensure lubricity in sliding between the drive shaft 2 and the shaft support portion 12c.
The rear body 12 has a pump-forming surface 120 that is raised in a circular shape on the negative side in the x-axis direction. The pump forming surface 120 is located on one end side of the cam ring 4 when the other end side of the cam ring 4 is defined as the pressure plate 6 side. A first suction port 122 is formed on the pump forming surface 120 so as to face one end surface in the axial direction of the cam ring 4 and open to the suction region. Further, the first discharge port 123 is formed so as to face one end surface in the axial direction of the cam ring 4 and open to the discharge region. Further, a suction-side back pressure groove 124 and a discharge-side back pressure groove 125 for introducing discharge pressure are formed in the back pressure chamber 33 on the pump forming surface 120.

(Configuration of control unit)
The control unit of the variable displacement vane pump 1 includes a first fluid pressure chamber A1, a second fluid pressure chamber A2, a control valve 7, and a discharge passage 20.
The discharge passage 20 is a passage for hydraulic oil that connects each part in the pump body 10. The front body 11 is formed with a substantially cylindrical control valve accommodating hole 116 extending in the y-axis direction, and the control valve 7 is accommodated in the control valve accommodating hole 116.
The control valve 7 switches the position of the spool 70 to switch the supply of hydraulic oil to the first fluid pressure chamber A1. In the state of FIG. 2, the control pressure oil passage 113 and a low pressure chamber 116b described later are in communication with each other, and suction pressure acts on the first fluid pressure chamber A1.
A valve spring 71 is installed in a compressed state on the positive side of the spool 70 in the y-axis positive direction, and constantly urges the spool 70 in the negative direction of the y-axis. A lid member 72 that closes the opening of the control valve housing hole 116 is screwed onto the negative side of the spool 70 in the y-axis negative direction.
The spool 70 is formed with a first small-diameter portion 70a, a first land portion 70b, a second small-diameter portion 70c, and a second land portion 70d sequentially from the y-axis negative direction side. The outer diameters of the first land portion 70b and the second land portion 70d are formed to be substantially the same as the inner diameter of the control valve housing hole 116, and the outer diameters of the first small diameter portion 70a and the second small diameter portion 70c are controlled. The valve housing hole 116 is formed to have a smaller diameter than the inner diameter. In the control valve accommodation hole 116, a high pressure chamber 116a is formed by a space surrounded by the inner circumference of the control valve accommodation hole 116, the outer circumference of the first small diameter portion 70a, the lid member 72, and the first land portion 70b. Further, a low pressure chamber 116b is formed by a space surrounded by the inner periphery of the control valve accommodating hole 116, the outer periphery of the second small diameter portion 70c, the first land portion 70b, and the second land portion 70d. An intermediate pressure chamber 116c is formed by the inner periphery of the control valve accommodating hole 116, the end surface on the y-axis positive direction side, and the second land portion 70d.

Both the high pressure chamber 116a and the intermediate pressure chamber 116c communicate with the discharge passage 20. The discharge passage 20 communicates with the discharge groove 111a and branches into a passage 21 and a passage 22. The passage 22 is connected to the high pressure chamber 116a, and the passage 21 is connected to the intermediate pressure chamber 116c. A metering orifice 23 is provided in the middle of the passage 21. As the discharge flow rate of the variable displacement vane pump 1 increases due to the metering orifice 23, the differential pressure across the metering orifice 23 increases. That is, as the discharge flow rate increases, the hydraulic pressure in the intermediate pressure chamber 116c becomes lower than the hydraulic pressure in the high pressure chamber 116a.
In the spool 70, a relief valve housing hole 70e that is open on the positive side in the y-axis is formed. The relief valve 8 is accommodated in the relief valve accommodation hole 70e. When the oil pressure in the intermediate pressure chamber 116c becomes too high, the intermediate pressure chamber 116c and the low pressure chamber 116b communicate with each other. The relief valve 8 is provided with a valve spring 80, a spring holding member 81, a ball plug 82, and a seat member 83 in this order from the y-axis negative direction side. The seat member 83 is formed with a through hole 83a penetrating in the axial direction, and is press-fitted into the relief valve accommodating hole 70e. The valve spring 80 is provided in a compressed state between the bottom surface of the relief valve housing hole 70e on the negative side in the y-axis and the spring holding member 81, and the ball plug 82 is connected to the seat member 83 via the spring holding member 81. Energized in the direction. The spool 70 is formed with a through hole 70f penetrating the relief valve housing hole 70e and the outer periphery of the second small diameter portion 70c in the vicinity of the ball plug 82. That is, the negative y-axis direction side of the relief valve housing hole 70e from the ball plug 82 communicates with the low pressure chamber 116b.

[Details of spool]
FIG. 3 is an enlarged view of the spool 70. In FIG. 3, for the sake of clarity, the relief valve 8 and the like are not shown, and the control valve accommodation hole 116 is schematically shown. In FIG. 3, the spool 70 moves to the positive side in the y-axis direction from FIG. 2, and the control pressure oil passage 113 and the high pressure chamber 116a communicate with each other, and the discharge pressure is in the first fluid pressure chamber A1. It is working.
A tapered portion 70g is formed between the first small diameter portion 70a and the first land portion 70b so that the diameter gradually increases from the first small diameter portion 70a toward the first land portion 70b. .
FIG. 4 is an enlarged view of a range indicated by B in FIG. The tapered portion 70g has an angle α (an angle shown in FIG. 4) with a surface S that intersects the virtual axis L extending in the longitudinal direction of the control valve housing hole 116 at a right angle at the end portion on the first land portion 70b side of the tapered portion 70g. α) is formed to be 45 degrees or more. Further, the taper portion 70g is formed in a range of at least 50 percent when the height of the first land portion 70b (height H shown in FIG. 4) with respect to the first small diameter portion 70a is 100 percent. At this time, the diameter of the end portion of the tapered portion 70g on the first land portion 70b side is formed to be substantially the same as the outer diameter of the first land portion 70b.

[Action]
(Supply of hydraulic oil to the first and second fluid pressure chambers)
Next, the effect | action regarding supply of hydraulic fluid is demonstrated.
The passage 22 is connected to the high pressure chamber 116a of the control valve accommodation hole 116, and the passage 21 is connected to the intermediate pressure chamber 116c. The differential pressure across the metering orifice 23 increases as the discharge flow rate of the variable displacement vane pump 1 increases by the metering orifice 23 provided in the middle of the passage 21. That is, as the discharge flow rate increases, the hydraulic pressure in the intermediate pressure chamber 116c becomes lower than the hydraulic pressure in the high pressure chamber 116a. The position of the spool 70 is controlled by the differential pressure at this time and the urging force of the valve spring 71 provided on the positive side of the spool 70 in the y-axis direction, thereby generating a control pressure.
Specifically, when the discharge flow rate of the variable displacement vane pump 1 is small and the differential pressure across the metering orifice 23 is small, the differential pressure between the hydraulic pressure in the high pressure chamber 116a and the hydraulic pressure in the intermediate pressure chamber 116c is small. Therefore, the y-axis positive biasing force received from the hydraulic pressure in the high pressure chamber 116a is smaller than the y-axis negative biasing force received by the spool 70 from the hydraulic pressure in the intermediate pressure chamber 116c and the valve spring 71. The y-axis is moving in the negative direction (the spool 70 is located at the position shown in FIG. 2). At this time, the first fluid passage A1 communicates with the low pressure chamber 116b, and the suction pressure is introduced as the control pressure.

As the discharge flow rate of the variable displacement vane pump 1 increases, the differential pressure across the metering orifice 23 increases as the discharge pressure increases. Along with this, when the y-axis positive biasing force received from the hydraulic pressure in the high-pressure chamber 116a becomes larger than the y-axis negative biasing force received by the spool 70 from the hydraulic pressure in the intermediate pressure chamber 116c and the valve spring 71, The spool 70 starts to move in the positive y-axis direction. When the spool 70 moves in the y-axis positive direction, the opening area of the control pressure oil passage 113 that opens to the low pressure chamber 116b is gradually reduced by the first land portion 70b, and conversely, the control pressure oil passage that opens to the high pressure chamber 116a. The opening area of 113 gradually increases. Finally, the communication between the low pressure chamber 116b and the control pressure oil passage 113 is blocked, and the high pressure chamber 116a and the control pressure oil passage 113 are communicated. At this time, a suction pressure is introduced as a control pressure into the first fluid pressure chamber A1. When the control pressure oil passage 113 is open to both the high pressure chamber 116a and the low pressure chamber 116b, the pressure adjusted to the pressure corresponding to each opening ratio is introduced into the first fluid pressure chamber A1 as the control pressure. Is done.
As described above, the control pressure corresponding to the position of the spool 70 is introduced into the first fluid pressure chamber A1. On the other hand, the second fluid pressure chamber A2 communicates with the second suction port 62 and the first suction port 122, and suction pressure is introduced. Accordingly, the suction pressure is always introduced into the second fluid pressure chamber A2, and thereby the variable displacement vane pump 1 is controlled only by the hydraulic pressure P1 of the first fluid pressure chamber A1. Since the hydraulic pressure P2 of the second fluid pressure chamber A2 is not controlled and always becomes P2 = suction pressure, the second fluid pressure chamber A2 can obtain a stable pressure, and can prevent the hydraulic disturbance and prevent the stable cam ring 4 The swing control can be executed.

(Eccentric operation of cam ring)
The positive y-axis biasing force that the cam ring 4 receives from the hydraulic pressure P1 of the first fluid pressure chamber A1 is greater than the sum of the hydraulic pressure P2 of the second fluid pressure chamber A2 and the negative biasing force received from the cam spring 201 in the y-axis. Then, the cam ring 4 moves in the positive y-axis direction while rolling on the support plate 40. By this movement, the volume of the pump chamber 13 on the y-axis positive direction side is increased, and the volume of the pump chamber 13 on the y-axis negative direction side is decreased.
When the volume of the pump chamber 13 on the negative y-axis side decreases, the amount of oil supplied from the suction side to the discharge side per unit time decreases, and the differential pressure between the upstream pressure and downstream pressure of the metering orifice 23 decreases. To do. As a result, the spool 70 is pushed back by the valve spring 71, and the control pressure of the spool 70 is lowered. Accordingly, the hydraulic pressure P1 of the first fluid pressure chamber A1 also decreases, and if the sum of the urging forces in the negative y-axis direction cannot be resisted, the cam ring 4 moves to the negative y-axis direction.
When the urging forces in the positive and negative directions of the y axis become substantially equal, the forces in the y axis direction acting on the cam ring 4 are balanced and the cam ring 4 stops. As a result, when the amount of oil increases, the differential pressure of the metering orifice 23 increases, and the spool 70 pushes the valve spring 71 to increase the valve control pressure. Therefore, contrary to the above, the cam ring 4 moves in the positive y-axis direction. Actually, the cam ring 4 does not cause movement hunting, and the eccentric amount of the cam ring 4 is determined so that the flow rate set by the orifice diameter of the metering orifice 23 and the valve spring 71 is constant.

(Foreign matter retention suppression)
The clearance between the inner diameter of the control valve housing hole 116 and the outer diameter of the first land portion 70b of the spool 70 suppresses catching when the spool 70 slides in the y-axis direction, and also from the high pressure chamber 116a to the low pressure chamber 116b. It is set so that the oil leakage to the can be reduced.
As described above, when the discharge flow rate of the variable displacement vane pump 1 increases, the spool 70 moves to the y-axis positive direction side, and the high pressure chamber 116a and the control pressure oil passage 113 are communicated with each other. Discharge pressure is acting on the high-pressure chamber 116a, and the hydraulic fluid supplied to the high-pressure chamber 116a is hydraulic fluid pumped by the variable displacement vane pump 1. Therefore, foreign matter may be mixed into the hydraulic fluid on the discharge side. There is. If the foreign matter stays between the first small-diameter portion 70a and the first land portion 70b, the spool 70 is locked, and the flow rate of the hydraulic oil flowing from the high-pressure chamber 116a into the first fluid pressure chamber A1 is small. As a result, there is a risk that the steering operation becomes heavy.
Therefore, in the first embodiment, the diameter is gradually increased from the first small diameter portion 70a toward the first land portion 70b between the first small diameter portion 70a and the first land portion 70b of the spool 70. A tapered portion 70g is formed, and the tapered portion 70g is formed in a range of at least 50 percent when the height of the first land portion 70b with respect to the first small diameter portion 70a is 100 percent.
The tapered portion 70g suppresses the retention of hydraulic oil between the first small-diameter portion 70a and the first land portion 70b, and foreign matter in the hydraulic oil stays between the control valve housing hole 116 and the first land portion 70b. Can be suppressed.
In addition, the diameter of the end portion of the taper portion 70g on the first land portion 70b side is formed to be substantially the same as the outer diameter of the first land portion 70b.
The tapered portion 70g is gently formed up to the first land portion 70b, thereby further suppressing the retention of the hydraulic oil in the first land portion 70b, and the foreign matter in the hydraulic oil is caused to flow into the control valve housing hole 116 and the first land portion 70b. It can suppress staying between.
Further, the angle α between the tapered portion 70g and the surface S perpendicular to the virtual axis L extending in the longitudinal direction of the control valve housing hole 116 at the end portion on the first land portion 70b side of the tapered portion 70g is 45 degrees or more. It formed so that it might become.
Thereby, the flow of the hydraulic oil in the first land portion 70b can be made smooth, and the foreign matter in the hydraulic oil can be prevented from staying between the control valve housing hole 116 and the first land portion 70b. it can.

〔effect〕
Hereinafter, effects of the variable displacement vane pump 1 of the present invention ascertained from the first embodiment will be listed.
(1) A pump body 10 (pump housing) having a pump element housing portion 112 inside, a drive shaft 2 pivotally supported by the pump body 10, and a movably provided pump body housing portion 112, formed in an annular shape The cam ring 4 is provided in the cam ring 4 and is rotationally driven by the drive shaft 2 and has a plurality of slits 31 in the circumferential direction. Among the plurality of vanes 32 that separate the plurality of pump chambers 13 together with the cam ring 4 and the space formed between the pump element housing portion 112 and the cam ring 4, the direction in which the eccentric amount of the cam ring 4 with respect to the drive shaft 2 increases. The first fluid pressure chamber A1 provided on the side where the volume is reduced by the movement of the cam ring 4 and the second fluid pressure chamber A2 provided on the side where the volume is increased, and the pump body 10, Po A first suction port 122 and a second suction port 62 (suction port) that open in a region of the pump chamber 13 whose volume increases with the rotation of the rotor 3, and a pump body 10 are provided. The first discharge port 123 and the second discharge port 63 (discharge port) that open to the area where the volume decreases with the rotation of 3 and the pump body 10 are communicated with the first and second suction ports 122 and 62. A suction passage 12a, a pump provided in the pump body 10, a discharge passage 20 (discharge passage) communicating with the first discharge port 123 and the second discharge port 63, and a meter provided in the middle of the discharge passage 20 (passage 22) A ring orifice 23, a control valve accommodating hole 116 (spool accommodating portion) provided in the pump body 10, and a spool provided in the control valve accommodating hole 116 so as to be axially movable in the longitudinal direction of the spool valve accommodating hole 116 70 and the longitudinal direction of the spool 70 in the inner space of the control valve accommodation hole 116 A high-pressure chamber 116a provided on one side (y-axis negative direction side) into which the upstream pressure of the metering orifice 23 is introduced, and the other side in the longitudinal direction of the spool 70 (y-axis positive side) in the inner space of the control valve housing hole 116 The intermediate pressure chamber 116c into which the downstream pressure of the metering orifice 23 is introduced, and between the high pressure chamber 116a and the intermediate pressure chamber 116c in the control valve housing hole 116 space, the suction passage 12a The low pressure chamber 116b communicating with the side, the control pressure oil passage 113 (communication passage) communicating with the control valve accommodation hole 116 and the first fluid pressure chamber A1, and the spool 70 are provided in the spool 70. A first land portion 70b that switches between a state in which 116a communicates with the first fluid pressure chamber A1 and a state in which the low pressure chamber 116b communicates with the first fluid pressure chamber A1, and the first land portion 70b. The first small-diameter portion 70a (small-diameter portion) formed on the high-pressure chamber 116a side and the first small-diameter portion 70a A tapered portion 70g provided at an end portion on the first land portion 70b side and formed so that the outer diameter of the first small diameter portion 70a gradually increases toward the first land portion 70b side. The outer diameter of the end portion on the first land portion 70b side is 50% or more when the radial dimension that is the protruding amount of the outer peripheral surface of the first land portion 70b from the outer peripheral surface of the first small diameter portion 70a is 100%. It was made to have the magnitude | size of.
Therefore, the taper portion 70g suppresses the retention of the hydraulic oil between the first small diameter portion 70a and the first land portion 70b, and the foreign matter in the hydraulic oil is between the control valve accommodation hole 116 and the first land portion 70b. It becomes possible to suppress staying in. For this reason, it is possible to prevent the spool 70 from being locked and a phenomenon that the steering operation becomes heavy by suppressing a decrease in the flow rate of the hydraulic oil flowing from the high pressure chamber 116a into the first fluid pressure chamber A1. be able to.

(2) The outer diameter of the end portion on the first land portion 70b side of the tapered portion 70g is set to be approximately the same as the outer diameter of the first land portion 70b.
Therefore, the taper portion 70g is formed gently up to the first land portion 70b, further restrains the hydraulic oil from staying in the first land portion 70b, and the foreign matter in the hydraulic oil is generated between the control valve housing hole 116 and the first land portion 70b. It can suppress staying between.
(3) The angle α between the tapered portion 70g and the surface S perpendicular to the virtual axis L extending in the longitudinal direction of the control valve housing hole 116 at the end portion on the first land portion 70b side of the tapered portion 70g is 45. It formed so that it might become more than degree.
Therefore, the flow of the hydraulic oil in the first land portion 70b can be made smooth, and foreign matter in the hydraulic oil can be suppressed from staying between the control valve housing hole 116 and the first land portion 70b. .

[Other Examples]
The present invention has been described based on the first embodiment. However, the specific configuration of each invention is not limited to the first embodiment, and even if there is a design change or the like without departing from the gist of the invention. Are included in the present invention.

2 Drive shaft
3 Rotor
4 Cam ring
10 Pump body
12a Intake passage
13 Pump room
20 Hydraulic circuit (discharge passage)
22 passage (discharge passage)
23 Metering orifice
31 Slit
32 Vane
62 Second inlet (inlet)
63 Second discharge port (discharge port)
70 spool
70a 1st small diameter part (small diameter part)
70b First Land (Land)
70g taper
112 Pump element housing
113 Control pressure oil passage
116 Control valve housing hole (spool housing)
116a High pressure chamber
116b Low pressure chamber
116c Medium pressure chamber
122 1st inlet (inlet)
123 First discharge port (discharge port)
A1 First fluid pressure chamber
A2 Second fluid pressure chamber

Claims (3)

A pump housing having a pump element housing on the inside;
A drive shaft pivotally supported by the pump housing;
A cam ring which is movably provided in the pump element accommodating portion and formed in an annular shape;
A rotor provided in the cam ring, driven to rotate by the drive shaft, and having a plurality of slits in the circumferential direction;
A plurality of vanes provided in the slits of the rotor so as to freely advance and retract, and together with the rotor and the cam ring, a plurality of pump chambers;
Of the space formed between the pump element housing portion and the cam ring, the first is provided on the side where the volume decreases as the cam ring moves in a direction in which the eccentric amount of the cam ring with respect to the drive shaft increases. A fluid pressure chamber and a second fluid pressure chamber provided on the side of increasing volume;
An inlet provided in the pump housing and opening in a region of the plurality of pump chambers whose volume increases with rotation of the rotor;
A discharge port that is provided in the pump housing and opens to a region of the plurality of pump chambers whose volume decreases with rotation of the rotor;
A suction passage provided in the pump housing and in communication with the suction port;
A discharge passage provided in the pump housing and communicating with the discharge port;
A metering orifice provided in the middle of the discharge passage;
A spool housing provided in the pump housing;
A spool provided in the spool housing portion so as to be axially movable in the longitudinal direction of the spool valve housing portion;
A high-pressure chamber that is provided on one side in the longitudinal direction of the spool in the inner space of the spool housing portion and into which upstream pressure of the metering orifice is introduced;
An intermediate pressure chamber that is provided on the other side in the longitudinal direction of the spool among the inner space of the spool housing portion and into which the downstream pressure of the metering orifice is introduced;
A low-pressure chamber that is provided between the high-pressure chamber and the intermediate-pressure chamber in the spool housing space, and communicates with the suction passage side;
A communication path communicating the spool housing portion and the first fluid pressure chamber;
A land portion that is provided in the spool and switches between a state in which the high pressure chamber and the first fluid pressure chamber communicate with each other as the spool moves, and a state in which the low pressure chamber and the first fluid pressure chamber communicate with each other;
A small diameter portion provided on the spool and formed on the high pressure chamber side than the land portion;
A taper portion provided at the land portion side end portion of the small diameter portion, and formed so that an outer diameter of the small diameter portion gradually increases toward the land portion side;
With
The outer diameter of the end portion on the land portion side of the tapered portion is 50% or more when the radial dimension that is the protruding amount of the outer peripheral surface of the land from the outer peripheral surface of the small diameter portion is 100%. A variable displacement vane pump characterized by comprising: In the variable displacement vane pump according to claim 1,
The variable displacement vane pump according to claim 1, wherein an outer diameter of the end portion on the land portion side of the taper portion is substantially the same as an outer diameter of the land portion. In the variable displacement vane pump according to claim 1,
The taper portion is formed so that an angle between the taper portion and the land portion side end portion of the taper portion is 45 degrees or more with respect to a plane perpendicular to the virtual axis extending in the longitudinal direction of the spool housing portion. This is a variable displacement vane pump.

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