JP2005233165A - Variable discharge-quantity vane pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vane pump constituted so that the discharge quantity can be smoothly changed, while reducing energy loss and noise in the vane pump. <P>SOLUTION: The vane pump comprises stopper pins 5 projecting from respective sides of the vanes 4, a stopper plates 8 capable of slide-contact to the stopper pins 5, a shaft 8b for reciprocating the stopper plates 8 in the radial direction of a rotor 3, and an actuator 9. The stopper pins 5 are shifted radially inside by driving the actuator 9 by a control part 9b through a drive circuit 9a so as to separate the tips of the vanes 4 from a cam face 2a. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a discharge amount variable vane pump capable of changing a discharge amount.

  In a vane pump used for a fuel supply pump of a diesel engine, a liquid power transmission device, or the like, a disk-like rotor is rotatably disposed in a cam ring. Since both side surfaces of the rotor and the cam ring are closed by side plates, a pump chamber is formed between the outer peripheral surface of the rotor and the inner peripheral surface of the cam ring, that is, the cam surface. A plurality of vane grooves extending in the radial direction are formed in the rotor, and the vanes are inserted into the vane grooves so as to be capable of reciprocating.

  Further, the vane is urged by a working fluid pressurized from the bottom of the vane groove or an elastic member provided at the inner end of the vane groove, and the tip thereof is in contact with the cam surface. Then, the working fluid introduced from the suction port is discharged from the discharge port while being pressurized by the vane in the pump chamber.

By the way, conventionally, a vane pump that can change the discharge amount as appropriate has been proposed.
For example, Patent Document 1 describes a vane pump in which the discharge amount is changed by biasing the center of a cam ring and the rotation center of a rotor. However, in such a vane pump, even when the deviation amount is reduced and the discharge amount is reduced, the tip of each vane is always in contact with the inner peripheral surface of the cam surface. Therefore, it is necessary to rotate the working fluid sealed between the vanes, and the energy loss of the pump tends to be relatively large.

In addition, for example, there is a method of providing a variable throttle valve in the suction port and changing the discharge amount in accordance with the throttle amount. In addition, a relief valve is provided downstream of the discharge port, and a part of the excess working fluid discharged from the discharge port is returned to the suction port via the relief valve, thereby substantially changing the discharge amount. Methods are also known.
JP-A-5-52188

  However, in the method of adjusting the suction amount by the variable throttle valve provided in the suction port as described above, depending on the degree of throttling, the pump chamber becomes low pressure, and cavitation is generated, resulting in noise and vibration, and further Fluid wear may occur. In addition, since the method using the relief valve does not basically change the discharge amount of the pump, an increase in energy loss cannot be denied when discharging an excessive working fluid.

  An object of the present invention is to provide a vane pump capable of smoothly changing the discharge amount by suppressing generation of noise and the like while suppressing energy loss in the vane pump.

Means for solving the above-described problems and their effects are described below.
According to the first aspect of the present invention, a rotor provided with a plurality of vanes provided so as to be capable of reciprocating in the radial direction and urged outward in the radial direction, the rotor being rotatably accommodated, and formed on an inner peripheral surface thereof A vane pump having a cam ring in which the tip portions of the plurality of vanes are in sliding contact with the cam surface, and a pair of side plates that close both sides of the cam ring and the rotor to form a pump chamber between the suction port and the discharge port. And a displacement means for displacing the vane located in the pump chamber in the radial direction of the rotor so as to be separated from the cam surface as the rotor rotates.

  In this configuration, the vane located in the pump chamber is displaced in the radial direction of the rotor, so that the position of the vane in sliding contact with the cam surface in the pump chamber can be changed. Therefore, through such a position change, the discharge amount of the vane pump can be changed without providing a restriction or the like on the suction side. As a result, while suppressing energy loss in the vane pump, generation of noise and the like can be suppressed and the discharge amount can be changed smoothly.

  Note that, as described in claim 2, such vane displacement means is provided so as to be capable of reciprocating in the radial direction with respect to the stopper pin provided on the side surface of the vane and the side plate. A stopper plate having a sliding surface that is in contact and restricts movement of the vane radially outward, and control means for reciprocating the stopper plate in the radial direction of the vane can be provided.

According to a third aspect of the present invention, in the vane pump according to the second aspect, the sliding surface of the stopper plate is a curved surface having an arcuate cross section.
According to this configuration, the stopper pin smoothly moves on the sliding surface of the stopper plate, and the impact when the tip of the vane separated from the cam surface by the stopper plate comes into contact with the cam surface again is reduced. be able to.

  According to a fourth aspect of the present invention, there is provided a rotor provided with a plurality of vanes provided so as to be reciprocally movable in the radial direction and urged outward in the radial direction; A vane pump having a cam ring in which the tip portions of the plurality of vanes are in sliding contact with the cam surface, and a pair of side plates that close both sides of the cam ring and the rotor to form a pump chamber between the suction port and the discharge port. The side plate is provided with the suction port for introducing the working fluid into the pump chamber, and the side plate having the suction port is provided to be rotatable about the rotation axis of the rotor. Displacement means for changing the distance in the rotational direction between the suction port and the discharge port by displacing the rotational phase is further provided.

  According to this configuration, the distance from the discharge port, in other words, the pumping volume of the pump chamber can be changed by changing the position of the suction port, and the discharge amount of the vane pump can be changed through the change of the same volume. become able to. As a result, while suppressing energy loss in the vane pump, generation of noise and the like can be suppressed and the discharge amount can be changed smoothly.

  According to a fifth aspect of the present invention, the vane pump is provided in an internal combustion engine, and the displacement means is controlled so that a displacement amount changed by the displacement means changes based on an operating state of the internal combustion engine. The vane pump according to any one of claims 1 to 4, further comprising a control means.

  According to this configuration, since the amount of displacement is controlled based on the engine operating state, the discharge amount of the vane pump can be adapted to the engine operating state, and an increase in energy loss due to wasteful discharge can be suppressed. Will be able to.

  According to a sixth aspect of the present invention, the vane pump is a fuel pump that supplies fuel to the internal combustion engine, and the control means is arranged so that the displacement amount changed by the displacement means becomes smaller as the engine load is higher. Vane pump to control the means.

  According to this configuration, as the engine load is higher, the amount of displacement changed by the displacement means becomes smaller. Therefore, the fuel supplied to the internal combustion engine can be increased, and the fuel corresponding to the load of the internal combustion engine is supplied. be able to.

(First embodiment)
Hereinafter, the vane pump of the present invention is embodied as a fuel pump that supplies fuel to an internal combustion engine.
The embodiment will be described with reference to FIGS. FIG. 1 is a front sectional view of the vane pump, FIG. 2 is a sectional side view of the main part of the vane pump, FIG. 3 is a rear view of the vane pump, and FIG.

  As shown in FIGS. 1 and 2, the vane pump 1 includes a cam ring 2, a rotor 3, a vane 4, a stopper pin 5, a front side plate 6, a rear side plate 7, a pair of stopper plates 8, and a pair of shafts 8b. ing. One end of the shaft 8 b is connected to the actuator 9. The actuator 9 is driven and controlled by the controller 9b through the drive circuit 9a, and reciprocates the shaft 8b in the radial direction of the rotor 3. These stopper pins 5, the stopper plates 8, and the shafts 8b constitute displacement means. In addition, a control means is configured by the drive circuit 9a and the control unit 9b that drive and control the operation of the displacement means.

  The cam ring 2 has an inner peripheral surface having a substantially elliptical cross section, and a cam surface 2a is formed by the inner peripheral surface. The cam surface 2a is formed such that the distance from the center C of the drive shaft 10 to the cam surface 2a is the longest at the upper end portion and the lower end portion thereof, and is the shortest at the left end portion and the right end portion. The distance from the center C to the cam surface 2a is gradually shortened toward the left and right ends.

  A rotor 3 is accommodated in the cam ring 2. The rotor 3 has a disk shape and is arranged such that the center of rotation coincides with the center C of the cam ring 2. The rotor 3 is connected and fixed to a drive shaft 10, and the drive shaft 10 rotates in the direction of arrow A in FIG. The outer diameter of the rotor 3 disposed in the cam ring 2 is formed to a length that does not slide in contact with the left end portion and the right end portion of the cam surface 2a. On both the upper and lower sides of the cam surface 2a of the cam ring 2, spaces S1 and S2 constituting the pump chamber P are formed by the cam surface 2a and the outer peripheral surface of the rotor 3.

  A plurality of vane grooves 11 extending in the radial direction are formed on the outer peripheral surface of the rotor 3 at equal angular intervals in the circumferential direction. The vane 4 is accommodated in the vane groove 11 so as to be slidable in the radial direction. The vane 4 is formed to have substantially the same width as the axial width of the rotor 3. A back pressure chamber 12 is formed at the groove bottom of the vane groove 11, and fuel as a working fluid is introduced into the back pressure chamber 12. The base end of the vane 4 is pressed in the radial direction of the rotor 3 by the fuel introduced into the back pressure chamber 12. Therefore, the tip of the vane 4 is urged radially outward and protrudes radially outward from the outer peripheral surface of the rotor 3.

  And when the rotor 3 rotates, the front-end | tip part of the vane 4 will slide, pressing the cam surface 2a. The tip of the vane 4 receives a reaction force from the pressing cam surface 2 a and rotates while sliding in contact with the cam surface 2 a while reciprocating in the radial direction along the vane groove 11. Accordingly, the amount of protrusion of the vane 4 is minimized so as to be minimized at both left and right ends of the cam surface 2a and is maximized at both upper and lower ends of the cam surface 2a. The pump chamber P is partitioned by a vane 4 located in the pump chamber P, and a vane chamber B is formed on both sides of the vane 4.

As shown in FIG. 2, on one side surface of the vane 4, the rear of the vane pump 1 (rear side plate 7
The stopper pin 5 protruding toward the side) is fixed. Accordingly, the stopper pin 5 is interlocked with both the rotational movement of the rotor 3 and the reciprocating movement of the vane 4 in the radial direction.

  A front side plate 6 and a rear side plate 7 are fixedly provided on both front and rear side surfaces of the cam ring 2. As the rotor 3 rotates, the front plate 6 and the rear plate 7 are in sliding contact with both the front and rear side surfaces of the rotor 3 and the front and rear side surfaces of the vane 4.

  A suction port P <b> 1 and a discharge port P <b> 2 communicating with the pump chamber P are formed on the sliding surface of the front side plate 6 on the rotor 3 side and the vane 4. Fuel as a working fluid in a tank (not shown) is introduced into the pump chamber P through the suction port P1, is pressurized with the rotation of the rotor 3, and is discharged from the pump chamber P through the discharge port P2. The fuel discharged in this way is supplied to the internal combustion engine.

  As shown in FIG. 3, a substantially elliptical annular passage groove 13 through which the stopper pin 5 passes is formed on the surface of the rear plate 7 on the rotor 3 side. The outer surface of the passage groove 13 is formed so as to be substantially in sliding contact with the outer peripheral surface in the longitudinal direction of the stopper pin 5 when the tip end portion of the vane 4 rotates in sliding contact with the cam surface 2a. Stopper plate accommodating portions 14 communicating with the passage grooves 13 are respectively formed at positions corresponding to the upper and lower sides of the cam surface 2a on the surface of the rear plate 7 on the rotor 3 side.

  The stopper plate accommodating portion 14 accommodates the stopper plate 8 so as to be capable of reciprocating in the radial direction with respect to the rear side plate 7. When the stopper plate 8 slides in the stopper plate housing portion 14 toward the center C direction, the stopper plate 8 enters the passage groove 13 and a sliding surface 8a formed on one side surface of the stopper plate 8 is formed. Is located in the passage groove 13.

  Accordingly, when each stopper plate 8 moves into the passage groove 13 through driving by the actuator 9, the stopper pin 5 comes into contact with the sliding surface 8a, and the displacement of the stopper pin 5 to the outside in the radial direction is restricted. As a result, the protruding amount of the vane 4 is limited, and the tip end portion is separated from the cam surface 2a. Here, the amount of separation is determined according to the amount of entry when each stopper plate 8 enters the passage groove 13. The sliding surface 8a is formed in an arc-shaped concave curved surface so that the stopper pin 5 can be smoothly moved when the stopper pin 5 moves from the cam surface 2a to the sliding surface 8a.

  In FIG. 3, the solid line indicates the position of the sliding surface 8 a when the stopper plate 8 is farthest from the passage groove 13, and the two-dot chain line indicates that the stopper plate 8 is closest to the passage groove 13. The position of the sliding surface 8a when the amount of entry is maximum is shown.

  As described above, in the vane pump 1, the vane 4 located in the pump chamber P is displaced radially inward of the rotor 3 so as to be separated from the cam surface 2a. The amount of displacement is adjusted based on the engine operating state.

  That is, when the required discharge amount set based on the engine operating state is small, the stopper plate 8 is moved to the center C side through driving by the actuator 9, and the sliding surface 8a is positioned in the passage groove 13. Therefore, the stopper pin 5 moves from the cam surface 2a to the sliding surface 8a, and moves while sliding on the sliding surface 8a.

Thus, when the stopper pin 5 passes on the sliding surface 8a, the stopper pin 5 is restricted from being displaced outward in the radial direction. Therefore, the vane 4 located in the pump chamber P has the tip portion separated from the cam surface 2a, and the protruding amount thereof is restricted. As a result, as shown in FIG. 4, a communication path 15 that communicates each vane chamber B is formed between the tip of the vane 4 and the cam surface 2 a.

By forming such a communication path 15, the fuel sucked from the suction port P1 flows backward through the communication path 15, and as a result, the discharge amount decreases.
On the other hand, when the required discharge amount set based on the engine operating state is large, the stopper plate 8 is moved radially outward through driving by the actuator 9 and passes through the sliding surface 8a, contrary to the above operation. Retreat from the groove 13. Thereby, the stopper pin 5 is displaced radially outward, and the restriction of the protruding amount is relaxed. As a result, the communication path 15 is closed, and the amount of intake for sucking fuel from the intake port P1, and thus the amount of discharge increases.

  Then, by continuously changing the position of the stopper plate 8 in accordance with the required discharge amount set based on the engine operating state in this way, the discharge amount of the vane pump 1 is changed to one that matches the engine operating state. The discharge amount can be adjusted smoothly while suppressing the energy loss.

According to the vane pump of the first embodiment, the following effects can be obtained.
(1) In the above embodiment, the protrusion amount of the vane 4 can be controlled by moving the sliding surface 8a of the stopper plate 8 forward and backward with respect to the passage groove 13. Accordingly, when the sliding surface 8a enters the passage groove 13, the communication passage 15 that communicates with each vane chamber B can be formed to change the suction input for sucking fuel from the suction port P1, and thus the discharge amount. . As a result, only the fuel relative to the required discharge amount is boosted, so that the energy loss of the vane pump can be suppressed.

  (2) In the above embodiment, the sliding surface 8a is formed as a concave curved surface having an arcuate cross section. Therefore, the impact when the stopper pin 5 is brought into sliding contact with the sliding surface 8a can be reduced, and the protruding amount of the vane 4 can be changed smoothly.

(3) In the above embodiment, the position of the stopper plate 8 is adjusted based on the engine operating state through the control unit 9b. Therefore, the required discharge amount according to the engine operating state can be secured, and the fuel suitable for the engine operating state can be appropriately supplied to the internal combustion engine.
(Second Embodiment)
Next, a second embodiment in which the vane pump of the present invention is embodied as a fuel pump that supplies fuel to an internal combustion engine will be described with reference to FIGS. This second embodiment is a modification of the displacement means of the first embodiment, and the changes will be described in detail below.

  As shown in FIG. 5, a front side plate 19 having a suction port P <b> 1 is disposed on one side surface of the cam ring 2. The front plate 19 is disposed to be rotatable in the circumferential direction of the rotor 3 with the center C as an axis. A driving roller 21 that rotationally drives the front plate 19 is pressed against the front plate 19. The drive roller 21 is driven and controlled by a control unit 9b (not shown) via a drive circuit 9a (not shown). When the driving roller 21 is rotationally driven by the control unit 9b, the rotational phase of the front side plate 19 is changed by receiving the driving force, and the rotational phase of the suction port P1 is displaced accordingly. The front side plate 19 and the drive roller 21 constitute displacement means.

A rear plate 20 having a discharge port P2 is fixed to the other side surface of the cam ring 2. The discharge port P2 is disposed at a position corresponding to the position formed on the front plate 6 in the first embodiment.

In the vane pump 1 configured as described above, the suction port P1 forming the pump chamber P is displaced in the circumferential direction of the rotor 3 so as to enlarge or reduce the distance from the discharge port P2.

  That is, when the required discharge amount set based on the engine operating state is small, the front plate 19 is rotated in the direction of the arrow shown in FIG. 6 through the rotational drive by the drive roller 21, and the distance from the discharge port P2 is reduced. Let As a result, the volume of the pump chamber P is reduced, and the suction amount and thus the discharge amount are reduced accordingly. Further, when the suction port P1 rotates and moves in the direction of the discharge port P2, the boosting force when boosting the fuel is weakened, and the pressure difference in each vane chamber B is also reduced.

  On the other hand, when the required discharge amount set based on the engine operation state is large, the front plate 19 is rotated counterclockwise through the rotational drive by the drive roller 21 contrary to the above operation, and the discharge port P2 Increase the distance. As a result, the volume of the pump chamber P is increased, and the suction amount and thus the discharge amount are increased accordingly.

  Then, by continuously changing the position of the suction port P1 in accordance with the required discharge amount set based on the engine operating state in this way, the discharge amount of the vane pump 1 is changed to one that matches the engine operating state. The discharge amount can be adjusted smoothly while suppressing the energy loss.

According to the vane pump of the second embodiment, the following effects can be obtained.
(1) In the above embodiment, the front plate 19 provided with the suction port P1 is disposed so as to be rotatable in the circumferential direction of the rotor 3 so that the rotational phase of the suction port P1 can be varied. Therefore, the distance between the suction port P1 and the discharge port P2 forming the pump chamber P can be enlarged and reduced, and the intake amount of fuel sucked into the pump chamber P, and hence the discharge amount can be changed. And since the fuel which opposes discharge amount is rotated, the energy loss of a vane pump can be suppressed.

  (2) In the above embodiment, the rotational phase of the front side plate 19 is adjusted based on the engine operating state through the control unit 9b. Therefore, the required discharge amount according to the engine operating state can be secured, and the fuel suitable for the engine operating state can be appropriately supplied to the internal combustion engine.

In addition, you may change the said embodiment as follows.
-Although the example applied to the fuel pump which supplies a fuel to an internal combustion engine was shown in the said embodiment, you may actualize to the pump used for the power steering apparatus of a motor vehicle, for example not only this but.

-Although the example applied to the pump whose working fluid is fuel was shown in the said embodiment, the working fluid may be water, lubricating oil, etc.
In the above embodiment, the rotor rotation shaft is concentric with the cam ring. However, the rotor rotation shaft may be arranged eccentrically with respect to the cam ring. .

In the above embodiment, the vane 4 is urged by the pressure of the fuel. However, this may be changed and the vane 4 may be urged by an elastic force of a spring member or the like.
In the first embodiment, the upper and lower stopper plates 8 are similarly moved when the actuator 9 is driven. However, at least one of the stopper plates 8 may be moved according to the set discharge amount. .

In the first embodiment, the suction port P1 and the discharge port P2 are provided on the rear plate 7. However, the suction port P1 and the discharge port P2 are provided on the front plate 6 or the rear plate 7 is changed. It is good also as a structure provided in both of the front plate 6 and the front plate 6.

In the first embodiment, the displacing means and the control means are provided on the rear plate 7 side. However, this may be changed and provided on the front plate 6 side, or provided on both the front plate 6 and the rear plate 7. Also good.
In the second embodiment, the suction port P1 is provided on the front plate 19 and the discharge port P2 is provided on the rear plate 20. However, the suction port P1 is provided on both the front plate 19 and the rear plate 20 on both sides. Alternatively, the discharge port P2 may be provided on the cam surface 2a.

The front sectional view of the vane pump of a 1st embodiment. The principal part side sectional view of the vane pump of a 1st embodiment. The rear view of the vane pump of 1st Embodiment. The principal part sectional view of the vane pump of a 1st embodiment. Sectional drawing of the principal part of the vane pump of 2nd Embodiment. The principal part side sectional view of the vane pump of a 2nd embodiment. Sectional drawing of the principal part of the vane pump of 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Vane pump, 2 ... Cam ring, 2a ... Cam surface, 3 ... Rotor, 4 ... Vane, 5 ... Stopper pin which comprises displacement means, 6, 19 ... Front side plate, 7, 20 ... Rear side plate, 8 ... Displacement means Stopper plate, 8b ... Shaft constituting displacement means, 9 ... Actuator, 9a ... Drive circuit constituting control means, 9b ... Control part constituting control means, 21 ... Drive roller, C ... Center, P1 ... Suction Port, S1, S2 ... space, P ... pump room.

Claims (6)

A rotor provided with a plurality of vanes provided so as to be reciprocally movable in the radial direction and urged outward in the radial direction; and the rotor is rotatably accommodated, and a cam surface formed on an inner peripheral surface of the plurality of vanes. In a vane pump having a cam ring in which a front end portion is in sliding contact, and a pair of side plates that close both sides of the cam ring and the rotor to form a pump chamber between a suction port and a discharge port,
A vane pump comprising: a displacement means for displacing the vane located in the pump chamber with the rotation of the rotor so that the vane is separated from the cam surface in the radial direction of the rotor. The vane pump according to claim 1, wherein
The displacement means is
A stopper pin provided on a side surface of the vane;
A stopper plate provided so as to be capable of reciprocating in the radial direction with respect to the side plate, and having a sliding surface that contacts the stopper pin and restricts movement of the vane radially outward;
A vane pump comprising control means for reciprocating the stopper plate in the radial direction of the vane. The vane pump according to claim 2,
A vane pump in which the sliding surface of the stopper plate is a curved surface having an arcuate cross section. A rotor provided with a plurality of vanes provided so as to be reciprocally movable in the radial direction and urged outward in the radial direction; and the rotor is rotatably accommodated, and a cam surface formed on an inner peripheral surface of the plurality of vanes. In a vane pump having a cam ring in which a front end portion is in sliding contact, and a pair of side plates that close both sides of the cam ring and the rotor to form a pump chamber between a suction port and a discharge port,
The suction port for introducing the working fluid into the pump chamber is provided on at least one side plate of the side plate, the side plate having the suction port is provided to be rotatable about the rotation axis of the rotor, and the rotational phase of the side plate is provided. Displacement means for changing the distance in the rotational direction between the suction port and the discharge port by displacing the suction port is further provided. The vane pump is provided in an internal combustion engine, and further includes control means for controlling the displacement means so that a displacement amount changed by the displacement means changes based on an operating state of the internal combustion engine. 4. The vane pump according to any one of 4. The vane pump according to claim 5, wherein
The vane pump is a fuel pump that supplies fuel to the internal combustion engine, and the control means controls the displacement means so that the amount of displacement changed by the displacement means becomes smaller as the engine load is higher.

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