JPH07293455A - Vane pump - Google Patents

Abstract

PURPOSE:To facilitate adjustment of the discharge state by switching the maximum discharge amount into the small flow rate through a process of moving a piston by the specific amount after introducing discharge pressure liquid into an operating chamber by means of a pressure control valve when the discharge pressure is increased to the intermediate pressure, and by cutting off the maximum discharge amount to the minimum discharge amount when the discharge pressure is increased to the maximum discharge pressure. CONSTITUTION:When the discharge pressure is increased and pilot pressure to a pressure control valve 64 is increased and it becomes the intermediate pressure or more set according to energizing force of a spring 66, the pressure control valve 64 is switched from the maximum discharge position (a) to the intermediate discharge pressure position. Thereby, pressure liquid is introduced into an operating chamber 54, and a piston 46 moves a cam ring 4 by the specific amount against energizing force of an energizing member 18, so as to make the piston come in contact with the bottom part 43 of a sliding hole 42. Thereby, the maximum discharge amount is switched from the large flow rate to the small flow rate. When the discharge pressure is further increased to the maximum pressure, the cam ring 4 is moved to the position where the eccentric amount of the cam ring 4 and the rotor 6 becomes the minimum, and the discharge amount is cut off to approximately zero.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vane pump capable of switching between a large flow rate, low pressure discharge state and a small flow rate, high pressure discharge state.

[0002]

2. Description of the Related Art Conventionally, a vane pump disclosed in Japanese Utility Model Publication No. 61-33272 is known as a vane pump capable of switching between a large flow rate, low pressure discharge state and a small flow rate, high pressure discharge state. Has been. This vane pump consists of a pressure compensating spring that applies an external force to the pump body in the radial direction from the outer circumference of the cam ring via a sliding shoe, and a cam plunger of the cam ring that opposes the biasing direction of the pressure compensating spring via an operating plunger. An operation cylinder for applying an external force from the outer circumference in the radial direction is provided. Then, the pilot plunger is projected into the operation cylinder so that the operation plunger can abut.

When the pressure receiving area of the pilot plunger x the discharge pressure exceeds the urging force of the pressure compensating spring, the cam ring is moved through the operation plunger in the direction in which the eccentricity of the cam ring decreases, and the discharge amount increases. To a small flow rate. By changing the size of the pressure receiving area of the pilot plunger, the height of the discharge pressure (set pressure) at the time of switching from the large flow rate to the small flow rate can be adjusted.

On the other hand, the retreat end position of the pilot plunger can be adjusted by an adjusting screw so that the maximum discharge amount of the pump can be adjusted when the pilot plunger is at the retreat end position at a large flow rate. In addition, the forward end position of the pilot plunger can be adjusted by a shim of arbitrary thickness provided in the front part of the pilot plunger in the pilot cylinder, and the maximum discharge of the pump when the pilot plunger is at the forward end position and a small flow rate is set. The amount can be adjusted.

[0005]

However, in such a conventional apparatus, the maximum discharge amount can be automatically switched from the large flow amount to the small flow amount when the discharge pressure from the pump becomes equal to or higher than the set pressure. The height of the set pressure must change the size of the pressure receiving area of the pilot plunger, and for that purpose, the diameter of the pilot plunger and the cylinder diameter must be changed, which makes adjustment very difficult. there were.

Further, although the maximum discharge amount at a large flow rate can be adjusted with an adjusting screw, the small flow rate is adjusted by adjusting the thickness of the shim. Therefore, the pilot cylinder is disassembled to reduce the thickness of the shim. There was a problem that it was very difficult to adjust because it had to be replaced with a different one.

Incidentally, in the above-mentioned conventional one, a manual switching valve and a pressure control valve are provided to switch the supply of the discharge pressure liquid to the pilot cylinder so that the pilot plunger is advanced to the forward end position and the discharge is performed. The pressure fluid is supplied to the pressure control valve. The manual switching valve can be switched to switch between a large flow rate, low pressure discharge state and a small flow rate, high pressure discharge state. It does, but it does not switch automatically.

When the discharge pressure exceeds a predetermined pressure, a sensor or the like for detecting the pressure is provided and an electromagnetic switching valve is provided instead of the manual switching valve in order to automatically switch. In addition, the electromagnetic switching valve may be switched, but a sensor, a control device, and the like are separately required, which complicates the device.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a vane pump whose discharge state can be easily adjusted with the object of solving the above problems.

[0010]

In order to achieve such an object, the present invention has the following constitution as means for solving the problem. That is, a cam ring with which a vane is in sliding contact is housed in the pump body so as to be movable in the radial direction, and a urging member for urging the cam ring in the radial direction is provided, and a maximum force for adjusting the urging force of the urging member A vane pump including a pressure adjusting member, wherein the cam ring moves in the radial direction against the biasing force of the biasing member due to an increase in discharge pressure, and the maximum discharge pressure can be adjusted according to the biasing force of the biasing member. In, the piston is slidably supported and slides by the introduction of pressure fluid into the working chamber to move the cam ring by a predetermined amount against the biasing force of the biasing member, and the discharge pressure can be variably set. The structure of the vane pump is characterized in that it has a pressure control valve for introducing the discharge pressure liquid into the working chamber when the intermediate pressure is reached.

It is also possible to adopt a configuration in which two sets of the piston and the pressure control valve are provided. In addition, a cam ring in which the vane is in sliding contact is housed in the pump body so as to be movable in the radial direction, and a biasing member that biases the cam ring in the radial direction is provided,
In a vane pump capable of adjusting the maximum discharge amount by restricting the movement of the cam ring in opposition to the urging force of the urging member, the vane pump is slidably supported and slides by introducing pressure fluid into the working chamber. A piston for moving the cam ring by a predetermined amount against the urging force of the urging member, and a pressure control valve for introducing a discharge pressure liquid into the working chamber when the discharge pressure reaches a preset intermediate pressure. And a maximum discharge amount adjusting member capable of adjusting the regulation position of the movement of the cam ring by the urging force of the urging member, and the regulation position of the sliding of the piston due to the introduction of the pressure liquid into the working chamber. This is the configuration of the vane pump characterized by including the intermediate discharge amount adjusting member.

Further, the intermediate discharge amount adjusting member is screwed into the pump body so as to be capable of advancing and retreating in opposition to the urging direction of the urging member, the piston is slidably inserted, and The intermediate discharge amount adjusting member may have a sliding hole for restricting the sliding of the piston against a biasing force of the biasing member at a predetermined position.

Further, the maximum discharge amount adjusting member may be screwed into the pump body so as to come into contact with the outer periphery of the cam ring so as to be able to move forward and backward. Moreover, the piston, the pressure control valve, and the intermediate discharge amount adjusting member are connected to each other.
It is good also as a structure with which it was equipped.

[0014]

In the vane pump having the above-mentioned structure, when the discharge pressure reaches the intermediate pressure due to the increase of the discharge pressure, the pressure control valve introduces the discharge pressure liquid into the working chamber and the piston slides. The cam ring is moved by a predetermined amount against the urging force of the urging member to switch the maximum discharge amount from the large flow amount to the small flow amount. Then, when the discharge pressure further increases and reaches the maximum discharge pressure corresponding to the biasing force of the biasing member adjusted by the maximum pressure adjusting member, the cam ring moves and is cut off to the minimum discharge amount.

The intermediate pressure is easily adjusted by the pressure control valve, and the maximum pressure is easily adjusted by the maximum pressure adjusting member. When two sets of the piston and the pressure control valve are provided, the pressure can be set in three stages and the adjustment thereof is easy.

In the vane pump having the above structure, the maximum discharge amount adjusting member adjusts the regulation position of the movement of the cam ring by the urging force of the urging member.
The maximum discharge amount until the discharge pressure reaches the intermediate pressure is adjusted. Then, when the discharge pressure reaches the intermediate pressure, the pressure control valve introduces the discharge pressure liquid into the working chamber, and the piston slides to move the cam ring by a predetermined amount against the urging force of the urging member. Switch the discharge rate from high flow rate to low flow rate. The intermediate discharge amount adjusting member adjusts the restriction position of the sliding of the viston due to the introduction of the pressure liquid into the working chamber, and adjusts the small flow rate when the intermediate pressure is reached.

When the intermediate discharge amount adjusting member is screwed into the pump body so as to be able to move forward and backward, the small flow rate can be easily adjusted by rotating the intermediate discharge amount adjusting member. Further, when the maximum discharge amount adjusting member is screwed into the pump body so as to be able to move forward and backward, the large flow rate can be easily adjusted by rotating the maximum discharge amount adjusting member.

Further, when two sets of the piston, the pressure control valve and the intermediate discharge amount adjusting member are provided, the discharge amount can be adjusted in accordance with the pressure which can be switched in three stages.

[0019]

Embodiments of the present invention will now be described in detail with reference to the drawings. As shown in FIG. 1, reference numeral 1 denotes a pump main body, a cylindrical hole 2 is formed in the pump main body 1, a cam ring 4 is housed in the cylindrical main body 2, and the pump main body 1 is rotatably supported. A large number of vanes 8 are slidably inserted into the rotor 6 so that the tips of the vanes 8 are in sliding contact with the inner peripheral surface 10 of the cam ring 4. The cam ring 4 is a thrust receiving mechanism 1 provided in the pump body 1.
It is configured so that it can be smoothly moved in the cylindrical hole 2 in the radial direction.

A shoe 14 is slidably inserted in a sliding hole 13 formed in a radial direction of the pump body 1 so that its tip is brought into contact with the outer periphery of the cam ring 4 and is connected to the sliding hole 13. A biasing member 18 using a coil spring or the like is housed in the housing hole 16. A holding member 20 is further slidably inserted in the storage hole 16, and the holding member 2
A pin 22 is provided upright on the outer periphery of the pin 0, and the pin 22 is inserted into a radial groove 24 formed on the inner periphery of the sliding hole 16 to prevent the pressing member 20 from rotating.

The pressing member 20 has a maximum pressure adjusting member 28 rotatably supported by a cover 26 that closes the housing hole 16.
The threaded portion 28a of the lock nut 30 is screwed into the maximum pressure adjusting member 28 protruding to the outside of the cover 26.
Are screwed together. Further, a small diameter hole 32 opened in the cylindrical hole 2 is formed in the pump body 1 facing the shoe 14 with the cam ring 4 in between, and an insertion hole 34 is formed so as to be connected to the small diameter hole 32. A screw hole 36 is formed so as to be connected to the insertion hole 34. The tip of the intermediate discharge amount adjusting member 38 is inserted into the insertion hole 34, the screw portion 39 of the intermediate discharge amount adjusting member 38 is screwed into the screw hole 36, and the lock nut 37 is further screwed into the screw portion 39. ing.

The intermediate discharge amount adjusting member 38 has a small diameter hole 32.
A communicating hole 40 is formed coaxially with the communicating hole 40, and a sliding hole 42 is formed in contact with the communicating hole 40, and a screw hole 44 is formed in contact with the sliding hole 42. The piston 46 is slidably inserted into the sliding hole 42, the small diameter portion 47 of the piston 46 is slidably inserted into the communication hole 40 and the small diameter hole 32, and the tip of the small diameter portion 47 is of the cam ring 4. It is designed to come into contact with the outer circumference. A drain groove 49 is formed in the small diameter portion 47 in the axial direction.

A transmission piston 48 having a convex tip abutting against the piston 46 is slidably inserted in the sliding hole 42, and the maximum discharge amount adjusting member 5 is inserted in the screw hole 44.
A threaded portion 51 of 0 is screwed in, and the transmission piston 48 can be slid by rotating the maximum discharge amount adjusting member 50. A lock nut 52 is screwed into the maximum discharge amount adjusting member 50. still,
The maximum discharge amount adjusting member 50 and the transmission piston 48 may be integrally formed.

A working chamber 54 is defined by the sliding hole 42, the piston 46 and the transmission piston 48.
An introducing hole 56 is formed in the intermediate discharge amount adjusting member 38 in communication with the working chamber 54, and an introducing hole 58 communicating with the introducing hole 56 is formed in the pump body 1.

Further, by the rotation of the rotor 6 which will be described later, the working oil in the tank 70 is sucked through the suction passage 72 and returned to the tank 70 through the drain passage 74, and the pressurized pressurized liquid is discharged. It is configured to be discharged through the passage 60. A branch path 62 from the discharge path 60 is connected to the introduction hole 58, and a pressure control valve 64 is interposed in the branch path 62.

The pressure control valve 64 is operated by the pilot pressure introduced from the branch passage 62 and the urging force of the spring 66, so that when the urging force of the spring 66 exceeds, the introduction hole 5
8 for communicating with the tank 68 via the branch passage 62 and an intermediate discharge position b for communicating the discharge passage 60 with the introduction hole 58 via the branch passage 62 when the acting force by the pilot pressure is higher. It has a configuration that switches to and. That is, when the pressure in the branch passage 62 is equal to or lower than the intermediate pressure P1 corresponding to the biasing force of the spring 66, it is switched to the maximum discharge position a, and when it is equal to or higher than the intermediate pressure P1, it is switched to the intermediate discharge position b.

The above-mentioned pressure control valve 64 may be integrated into the pump body 1 as shown in FIG. In this pressure control valve 64, a valve body 78 having a ring-shaped recess 77 is slidably inserted into a slide hole 76 formed in the pump body 1, and the pressure control valve 64 is formed so as to be connected to the slide hole 76. A pair of spring receiving members 81a,
The spring 66 sandwiched by 81b is stored. A plug 80 is screwed to the pump body 1, and the biasing force of the spring 66 can be varied by the adjusting screw 82 screwed into the plug 80.

In the pump body 1, a supply hole 84 connected to the branch passage 62 is formed in communication with the tip end side of the sliding hole 76, and a discharge hole 86 in communication with the tank 68 and an introduction hole 56 are formed. A communication hole 88 that communicates is formed. Then, when the pilot pressure introduced into the sliding hole 76 via the supply hole 84 acts on the valve body 78 against the biasing force of the spring 66, and the biasing force of the spring 66 exceeds this acting force. The discharge hole 86 and the communication hole 88 are communicated with each other through the recess 77, and when the acting force by the pilot pressure exceeds the urging force, the supply hole 84 and the communication hole 88 are communicated with each other through the sliding hole 76. Is configured.

Next, the operation of the vane pump of this embodiment described above will be described. First, when the rotor 6 is rotationally driven by a drive source (not shown), the hydraulic fluid in the tank 70 is sucked through the suction passage 72, and the pressurized hydraulic fluid is discharged from the discharge passage 60. At that time, the cam ring 4 acts in the radial direction against the urging force of the urging member 18 according to the discharge pressure.

When the load of an actuator such as a cylinder (not shown) connected to the discharge passage 60 is small, the discharge pressure is also small, and at that time, the cam ring 4 is biased by the urging member 18.
It is pushed in the radial direction via the shoe 14 by the urging force of.
Further, since the pressure in the branch passage 62 of the pressure control valve 64 is low, the urging force of the spring 66 exceeds the acting force of the pilot pressure, and the working chamber 54 has the introduction holes 56, 58 and the branch passage 62.
Is communicated with the tank 68 via.

Therefore, the outer periphery of the cam ring 4 contacts the tip of the piston 46, and the movement of the cam ring 4 is restricted by the position of the maximum discharge amount adjusting member 50 via the transmission piston 48, so that the rotor 6 and the cam ring 4 are restrained. Eccentricity S with 4
A large flow rate Q2 of hydraulic fluid is discharged from the discharge passage 60.

When the discharge pressure increases and the pilot pressure to the pressure control valve 64 increases to the intermediate pressure P1 or higher set according to the urging force of the spring 66, the pressure control valve 64 moves from the maximum discharge position a. Switching to the intermediate discharge position b. As a result, the pressure liquid from the discharge passage 60 enters the working chamber 54 in the branch passage 6.
2. The piston 46 is introduced through the introduction passages 56 and 58.
Against the urging force of the urging member 18, the cam ring 4 is moved by a predetermined amount until the piston 46 abuts the bottom portion 43 of the sliding hole 42 and the sliding is restricted. As the cam ring 4 moves, the amount S of eccentricity with the rotor 6 decreases, and the maximum discharge amount is switched from the large flow rate Q2 to the small flow rate Q1, as shown in FIG.

Until the maximum pressure P2 is increased, discharge is performed with a small flow rate Q1 according to the sliding of the piston 46, and when the load increases and the discharge pressure reaches the maximum pressure P2, the pressure is increased. The cam ring 4 resists the urging force of the urging member 18 and is moved to a position where the eccentric amount S between the cam ring 4 and the rotor 6 is minimized. As a result, in this embodiment, as shown in FIG. 5, the discharge amount is cut off to almost zero.

The level of the intermediate pressure P1 can be easily adjusted by adjusting the biasing force of the spring 66 of the pressure control valve 64, and in the case shown in FIG. 2, by rotating the screw 82. . The maximum pressure P2 can be easily adjusted by rotating the maximum pressure adjusting member 28, moving the pressing member 20, and changing the biasing force of the biasing member 18.

On the other hand, the maximum discharge amount until the discharge pressure reaches the intermediate pressure P1, that is, the large flow rate Q2, is obtained by rotating the maximum discharge amount adjusting member 50 to transfer piston 48.
Can be slid to change the regulation position where the cam ring 4 is pushed and moved by the urging force of the urging member 18 by the regulation position where the piston 46 contacts the transmission piston 48, and the adjustment can be easily performed.

In addition, the maximum discharge amount from the intermediate pressure P1 to the maximum pressure P2, that is, the small flow rate Q1 is obtained by rotating the intermediate discharge amount adjusting member 38 to cause the bottom portion 4 of the sliding hole 42 to move.
3 is moved, the piston 46 moves the biasing member 18
By changing the restriction position where the cam ring 4 and the rotor 6 pushed by the piston 46 can be changed by changing the restricting position that can slide against the urging force of, the adjustment can be easily performed.

As a result, when the load is small, the actuator or the like can be driven at a high speed in the discharge state of the intermediate pressure P1 at the large flow rate Q2, and when the load is large, the actuator or the like in the discharge state of the maximum pressure P2 at the small flow rate Q1. Can be driven with a large force and can be automatically switched according to the load. Therefore, it can be efficiently driven by a small drive source, and a complicated control device is unnecessary.

Next, a second embodiment different from the above-mentioned first embodiment will be described with reference to FIG. The same members as those in the first embodiment described above are designated by the same reference numerals, and detailed description thereof will be omitted. The same applies below. The maximum discharge amount adjusting member 50 and the transmission piston 48 of the first embodiment described above are integrally formed and screwed into the screw hole 44 as a plug 90. Further, a screw hole 92 is formed in the pump body 1 so as to face the urging direction of the urging member 18 and communicates with the cylindrical hole 2 in the radial direction. The member 94 is screwed, and the pair of lock nuts 96
Is screwed on.

In the second embodiment, the maximum discharge amount adjusting member 94 is rotated to abut against the outer periphery of the cam ring 4, and the radial movement of the cam ring 4 by the urging force of the urging member 18 is adjusted to the maximum discharge amount adjusting member. It is configured to be regulated by 94. By rotating the maximum discharge amount adjusting member 94, it is possible to easily adjust the maximum discharge amount until the intermediate pressure P1 is reached, that is, the large flow rate Q2.

Further, in the case of the first embodiment described above, when the intermediate discharge amount adjusting member 38 is rotated, the maximum discharge amount adjusting member 50 also moves with respect to the cam ring 4, and the intermediate discharge amount adjusting member 38 moves. When the small flow rate Q2 is adjusted by 38, the maximum discharge amount adjusting member 50 must be readjusted. According to the second embodiment, the maximum discharge amount adjusting member 94 and the intermediate discharge amount adjusting member 38 can be adjusted independently, so that the adjustment becomes easier.

Further, a third embodiment different from the above-mentioned first and second embodiments will be described with reference to FIG. In the third embodiment, two sets of the piston 46, the pressure control valve 64, and the intermediate discharge amount adjusting member 38 of the first embodiment are used, that is, the first and second pistons 46a and 46b and the first and second pressures. The control valves 64a and 64b and the first and second intermediate discharge amount adjusting members 38a and 38b are provided, and the other configurations are the same as those in the first embodiment. The same members as those in the first embodiment are designated by subscripts a and b, and detailed description thereof will be omitted.

In the third embodiment, the transmission piston 48 and the maximum discharge amount adjusting member 50 of the first embodiment are integrally formed, and the first and second screw holes 44a and 44b are respectively formed.
The first and second maximum discharge amount adjusting members 96a and 96b are screwed in and configured. The large flow rate Q3 is the first and second
It suffices to rotate one of the maximum discharge amount adjusting members 96a and 96b for adjustment, and it is not necessary to adjust both. The other may be used as a mere stopper.

Also, in the third embodiment, the first sliding hole 42a is
And the second sliding hole 42b are different in the positions of the bottom portions 43a and 43b, and the first piston 46a is the second piston 46a.
The sliding distance is longer than b. In the first pressure control valve 64a, the intermediate pressure P2 is set by adjusting the biasing force of the spring 66a, and in the second pressure control valve 64b, the intermediate pressure P1 lower than the intermediate pressure P2 is set by adjusting the biasing force of the spring 66b. Has been done.

Thus, as shown in FIG. 6, when the discharge pressure is lower than the intermediate pressure P1, the cam ring 4 is pushed by the urging force of the urging member 18, and the first and second maximum discharge amount adjusting members 96a. , 96b are in contact with the first and second pistons 46a, 46b, the radial movement of which is restricted at a position where the outer circumferences of the first and second pistons 46a, 46b are in contact with each other. Quantity, that is, large flow rate Q3
Is obtained.

The height of the intermediate pressure P1 can be easily adjusted by adjusting the biasing force of the spring 66b of the second pressure control valve 64b. The large flow rate Q3 is adjusted by
By rotating one of the second maximum discharge amount adjusting members 96a and 96b, the cam ring 4 moves the first and second pistons 46a and 46b.
It is possible to easily adjust by changing the restriction position until it comes into contact with b.

When the discharge pressure is between the intermediate pressures P1 and P2, the second pressure control valve 64b introduces the pressure liquid into the second working chamber 54b, so that the second piston 46b moves into the second sliding hole 42b. It is slid to the regulation position where it abuts on the bottom portion 43b. As a result, the cam ring 4 causes the biasing member 18 to
The eccentric amount S between the cam ring 4 and the rotor 6 is reduced, and the maximum discharge amount is switched to the intermediate discharge amount Q2 accordingly.

The adjustment of the intermediate pressure P1 at this time is performed by the spring 66b of the second pressure control valve 64b as described above, and the adjustment of the intermediate pressure P2 is performed by the urging force of the spring 66a of the first pressure control valve 64a. It can be easily adjusted by adjusting. Further, the adjustment of the intermediate discharge amount Q2 changes the regulation position where the second piston 46b can slide by rotating the second intermediate discharge amount adjusting member 38b and moving the bottom portion 43b of the second sliding hole 42b. And can be easily adjusted.

Further, when the intermediate pressure P2 is exceeded, pressure liquid is introduced into the first working chamber 54a by the first pressure control valve 64a, and the first piston 46a comes into contact with the bottom portion 43a of the first sliding hole 42a. Sliding to the position, the eccentricity S between the cam ring 4 and the rotor 6 is further reduced. Accordingly, the maximum discharge amount is switched to the small flow rate Q1.

The intermediate pressure P2 at this time is adjusted by adjusting the urging force of the spring 66a of the first pressure control valve 64a as described above, and the small flow rate Q1 is adjusted by the first intermediate discharge amount adjusting member 38a. Is rotated to move the bottom portion 43a of the first sliding hole 42a, the regulation position at which the first piston 46a can slide can be changed and easily adjusted.

As described above, according to the third embodiment, the pressure can be switched between the two intermediate pressures P1, P2 and the maximum pressure P3 in three steps, and the respective pressures can be easily adjusted. Further, the flow rate can be switched to two intermediate flow rates Q1 and Q2 and a large flow rate Q3 in three steps, and the respective flow rates can be easily adjusted.

The present invention is not limited to the embodiments as described above, and may be carried out in various modes without departing from the gist of the present invention.

[0052]

As described above in detail, the vane pump of the present invention can switch between a discharge state of a medium pressure at a large flow rate and a discharge state of a maximum discharge pressure at a small flow rate.
The intermediate pressure can be easily adjusted by the pressure control valve, and the maximum discharge pressure can be easily adjusted by the maximum pressure adjusting member. In the case where two sets of pistons and pressure control valves are provided, the pressure can be set in three stages and each pressure can be easily adjusted by the pressure control valve.

Further, in the case where the maximum discharge amount adjusting member and the intermediate discharge amount adjusting member are provided, it is possible to switch between a discharge state of a large flow rate and an intermediate pressure and a discharge state of a small flow rate and a maximum discharge pressure. The maximum discharge amount adjusting member can easily adjust the flow amount at the large flow amount, and the intermediate discharge amount adjusting member can easily adjust the flow amount at the small flow amount.

Further, in the case where the intermediate discharge amount adjusting member is screwed into the pump main body, the small flow rate can be easily adjusted with a simple structure by rotating the intermediate discharge amount adjusting member. Moreover, in the case where the maximum discharge amount adjusting member is screwed into the pump main body, the large flow rate can be easily adjusted with a simple configuration by rotating the maximum discharge amount adjusting member. In addition, the piston, the pressure control valve, and the intermediate discharge amount adjusting member
With the set, you can set the flow rate in three stages,
Each flow rate can be easily adjusted by the intermediate discharge amount adjusting member.

[Brief description of drawings]

FIG. 1 is a sectional view of a vane pump as a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of a main part of a vane pump in which the pressure control valve according to the present embodiment is integrally incorporated in a pump body.

FIG. 3 is a sectional view of a vane pump as a second embodiment.

FIG. 4 is a sectional view of a vane pump as a third embodiment.

FIG. 5 is a graph showing the relationship between the discharge amount and the discharge pressure in the first embodiment.

FIG. 6 is a graph showing the relationship between the discharge amount and the discharge pressure of the third embodiment.

[Explanation of symbols]

1 ... Pump body 4 ... Cam ring
8 ... Vane 18 ... Energizing member 28 ... Maximum pressure adjusting member 3
8 ... Intermediate discharge amount adjusting member 42 ... Sliding hole 46 ... Piston 5
0 ... Maximum discharge amount adjusting member 54 ... Working chamber 60 ... Discharge passage 6
2 ... Branch passage 64 ... Pressure control valve 72 ... Suction passage 9
4 ... Maximum discharge rate adjusting member

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masahiro Furuya 1 Toyota Town, Toyota City, Aichi Prefecture, Toyota Motor Co., Ltd. (72) Inventor, Nori Mori 1 Toyota Town, Toyota City, Aichi Prefecture, Toyota Motor Corporation ( 72) Inventor Takeshi Kojima 1-1-1, Asahi-cho, Kariya City, Aichi Prefecture Toyota Koki Co., Ltd.

Claims (6)

[Claims] 1. A cam ring, in which a vane is in sliding contact, is housed in a pump body so as to be movable in a radial direction, and a biasing member for biasing the cam ring in a radial direction is provided, and the biasing force of the biasing member is provided. A maximum pressure adjusting member for adjusting is provided, and the cam ring moves in the radial direction against the biasing force of the biasing member due to an increase in discharge pressure, and the maximum discharge pressure is adjusted according to the biasing force of the biasing member. In a possible vane pump, a piston that is slidably supported and slides by introducing pressure fluid into the working chamber to move the cam ring by a predetermined amount against the biasing force of the biasing member, and the discharge pressure is A vane pump comprising: a pressure control valve that introduces discharge pressure liquid into the working chamber when a variably settable intermediate pressure is reached. 2. The vane pump according to claim 1, comprising two sets of the piston and the pressure control valve. 3. A cam ring, in which a vane is in sliding contact, is housed in the pump body so as to be movable in the radial direction, and a biasing member for biasing the cam ring in the radial direction is provided, and the cam ring opposes the biasing force of the biasing member. In a vane pump that regulates the movement of the cam ring and adjusts the maximum discharge amount, the vane pump is slidably supported and slides by introducing pressure fluid into the working chamber so that the cam ring is biased by the biasing member. A piston for moving a predetermined amount against the pressure, a pressure control valve for introducing discharge pressure liquid into the working chamber when the discharge pressure reaches a preset intermediate pressure, and a biasing force of the biasing member. A maximum discharge amount adjusting member capable of adjusting the restricting position of the movement of the cam ring; and an intermediate discharge amount adjusting member capable of adjusting the restricting position of sliding of the piston due to introduction of the pressure liquid into the working chamber. That Vane pump and butterflies. 4. The intermediate discharge amount adjusting member is screwed into the pump body so as to be able to move forward and backward so as to face the urging direction of the urging member, and the piston is slidably inserted,
4. The vane pump according to claim 3, wherein a slide hole that restricts sliding of the piston against a biasing force of the biasing member at a predetermined position is formed in the intermediate discharge amount adjusting member. 5. The vane pump according to claim 3, wherein the maximum discharge amount adjusting member is screwed into the pump body so as to come into contact with the outer periphery of the cam ring so as to be able to move forward and backward. 6. The vane pump according to claim 3, wherein two sets of the piston, the pressure control valve, and the intermediate discharge amount adjusting member are provided.