JP5121745B2 - Variable displacement pump - Google Patents

Description

  The present invention relates to a variable displacement pump that supplies hydraulic fluid to an external device.

  As a pump for a power steering device in an automobile, a pump directly driven by an engine may be used. This type of pump is a variable displacement type that can reduce the discharge amount per rotation according to the increase in the rotation speed for high-speed running that requires a high engine rotation speed and does not require a large pump discharge volume. There is a vane pump. Many variable displacement vane pumps are configured to keep the discharge rate constant as the rotational speed increases. However, when the traveling speed of the automobile is high, it is required to further reduce the discharge amount and improve the efficiency. As means for that, a method has been proposed in which the orifice provided in the discharge passage is throttled by the movement (swinging) of the cam ring (see Japanese Patent Application Laid-Open No. 2001-140772, etc.).

JP 2001-140772 A

  However, in the above method of reducing the discharge amount by changing the flow area of the orifice provided in the discharge passage based on the movement of the cam ring, a large change in the flow path area is ensured with respect to the flow rate passing through the orifice. However, it was difficult to increase the range of change in the discharge amount.

  An object of the present invention is to provide a variable displacement pump that can greatly reduce the pump discharge even when the rotational speed increases.

  In order to achieve the above object, the present invention is a variable displacement pump that supplies hydraulic fluid to an external device, and has a pump housing having a pump element housing portion, and is pivotally supported by the pump housing and driven by a drive source. A drive shaft, an annular cam ring movably provided in the pump element accommodating portion, and a hydraulic fluid provided in the cam ring for discharging the working fluid sucked by the rotational drive of the drive shaft, and for the drive shaft A pump element that changes a specific discharge amount that is a discharge amount per rotation in accordance with a change in the eccentric amount of the cam ring, and is provided between the pump element housing portion and the cam ring, and the volume increases as the specific discharge amount increases. It is provided between the first fluid pressure chamber provided on the decreasing side, the pump element accommodating portion and the cam ring, and the specific discharge amount is increased. A second fluid pressure chamber provided on the side where the volume increases, a suction port formed in the pump housing and opened to a suction region of the pump element, and formed in the pump housing, in a discharge region of the pump element. An opening discharge port, a discharge passage connecting the discharge port and the external device, a metering orifice provided in the discharge passage, a spool hole formed in the pump housing, and a slide in the spool hole A spool that is movable, a valve high-pressure chamber that is provided on one side of the spool in the moving direction and into which pressure from the discharge port is introduced, and a downstream side of the metering orifice that is provided on the other side of the spool in the moving direction A valve intermediate pressure chamber into which a side pressure is introduced and the first fluid pressure chamber or the second fluid pressure chamber communicate with the sliding of the spool. A valve hole whose flow path area is variably controlled, and controls the pressure introduced into the first fluid pressure chamber or the second fluid pressure chamber according to a change in the flow path area of the valve hole, A control valve for controlling the moving position of the cam ring, a high-pressure introduction path connecting the discharge port and the valve high-pressure chamber, and a medium-pressure introduction path connecting the valve intermediate pressure chamber and the downstream side of the metering orifice. A branch passage connected to a low pressure region that is connected to the middle of the high pressure introduction path or the valve high pressure chamber and maintained at about atmospheric pressure, and on the high pressure introduction path, the discharge port is more than a connection point with the branch passage. A first throttle part provided at a position on the side, and a second throttle part provided in the branch passage, wherein either the first throttle part or the second throttle part moves the cam ring According to When the first restrictor is a variable orifice, the variable orifice increases the flow area as the cam ring moves in the direction in which the specific discharge amount decreases. When the second restrictor is a variable orifice, the variable orifice increases the flow path area as the cam ring moves in the direction in which the specific discharge amount increases.

  According to the present invention, since the pump discharge amount can be greatly reduced even when the rotational speed is increased, energy saving can be achieved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a front view of the variable displacement vane pump according to the first embodiment of the present invention, in which a partial cross section is taken during low rotation. 2 is a cross-sectional view taken along line AA in FIG. 1, and a cross section taken along line BB in FIG. 2 is FIG.

  The variable displacement vane pump shown in these drawings includes a pump housing 71, a drive shaft (shaft) 13, a cam ring 15, a pump element 72, a discharge passage 38, a metering orifice 23, a control valve 30, a high pressure. An introduction path 73, an intermediate pressure introduction path 38 a, a branch path 75, a variable damper orifice (first throttle part) 20, and a throttle (second throttle part) 60 are provided.

  The pump housing 71 is mainly formed by a concave front body 10, a rear cover 19 fitted to the front body 10, and a pressure plate 27 (see FIG. 2) that partitions the front body 10. In the front body 10, the pressure plate 27 and the rear cover 19, the pump element accommodating portion 70 for accommodating the pump element 72, and the pressure chamber 26 into which the hydraulic fluid pressurized by the pump element 72 is introduced (see FIG. 2). Is formed.

  The pump element 72 is mainly formed by the rotor 11 and the vane 14. A shaft 13 driven by a driving source (for example, an engine or the like) is connected to the rotor 11, and the shaft 13 is supported by a bearing 28 (see FIG. 2) provided in the pump housing 71 (front body 10). Yes. A plurality of slots 29 are provided on the outer periphery of the rotor 11, and vanes 14 that can be protruded and retracted in the radial direction of the rotor 11 are inserted into the slots 29.

  A space between the rotor 11 and the cam ring 15 is divided by the vane 14, thereby forming a plurality of vane chambers 18. The vane chamber 18 is connected to the discharge port 21 in a region where the volume is reduced due to the rotation of the rotor 11 counterclockwise in FIG. 1, and is connected to the suction port 22 in a region where the volume is increased.

  The adapter 12 is fitted in the pump element accommodating portion 70. An annular cam ring 15 is swingably attached to the adapter 12 via a support pin 16, and the cam ring 15 is arranged to be eccentric with respect to the drive shaft 13 that is the rotation center of the rotor 11. When the amount of eccentricity of the cam ring 15 with respect to the drive shaft 13 (hereinafter sometimes referred to as “the amount of eccentricity of the cam ring 15”) is changed, the specific discharge amount that is the discharge amount per one rotation of the pump can be changed. The cam ring 15 is urged by the compression coil spring 17 in the direction in which the specific discharge amount is maximized.

  A first fluid pressure chamber 40 and a second fluid pressure chamber 41 are provided between the adapter 12 and the cam ring 15. The first fluid pressure chamber 40 is a fluid chamber provided on the side where the volume decreases (that is, the left side in FIG. 1) as the inherent discharge amount of the pump increases (the eccentric amount of the cam ring 15 increases). The two-fluid pressure chamber 41 is a fluid chamber provided on the side where the volume increases (that is, on the right side in FIG. 1) as the intrinsic discharge amount of the pump increases (the eccentric amount of the cam ring 15 increases).

  The control valve 30 includes a spool hole 30a formed in the pump housing 71 (front body 10), a spool 30b slidably provided in the spool hole 30a, a spring 30c for urging the spool 30b, The first fluid pressure chamber 40 or the second fluid pressure chamber 41 communicates with the valve hole 33 or the like whose flow passage area is variably controlled as the spool 30b slides.

  A valve high-pressure chamber 37 into which pressure from the discharge port 21 is introduced via a high-pressure introduction path 73 is provided on one side in the moving direction of the spool 30b, and an intermediate pressure is introduced on the other side in the moving direction of the spool 30b. A valve intermediate pressure chamber (spring chamber) 36 into which the downstream pressure of the metering orifice 23 is introduced via the passage 38a is provided. A spring 30 c is provided in the valve intermediate pressure chamber 36, and the spring 30 c biases the spool 30 b toward the valve high pressure chamber 37.

  An annular groove 30d is provided in the circumferential direction of the center portion of the spool 30b. Between the annular groove 30d and the spool hole 30a, a valve low-pressure chamber 30e into which pressure from the suction port (that is, tank pressure) is introduced is provided. The valve low pressure chamber 30e communicates with the valve hole 33 in a state where the flow path area is maximum when the spool 30b is located at the left end in FIG. Then, as the spool 30b moves to the right in FIG. 1, the flow path area becomes narrower, and finally the connection between the valve low pressure chamber 30e and the valve hole 33 is disconnected.

  The control valve 30 generally operates according to the magnitude relationship between the force due to the pressure of the valve high pressure chamber 37, the force due to the pressure of the valve intermediate pressure chamber 36, and the force due to the spring force of the spring 30c. For example, the force due to the pressure difference between the valve high pressure chamber 37 and the valve intermediate pressure chamber 36 (the rightward force in FIG. 1) becomes larger than the force due to the spring 30c (the leftward force in FIG. 1), and the spool 30b When moving to the right side in FIG. 1, the flow path area between the valve hole 33 and the valve high pressure chamber 37 increases, and the flow path area between the valve hole 33 and the valve low pressure chamber 30e decreases.

  By the way, a relief valve 32 is installed in the spool 30 b of the control valve 30. The relief valve 32 includes a seat portion 32a, a ball 32b, a retainer 32c, and a spring 32d. When the force due to the discharge pressure acting on the valve intermediate pressure chamber 36 reaches or exceeds the set pressure determined by the spring 32d, the ball 32b and the retainer 32c move together in the left direction in FIG. 1 to move the seat portion 32a to the valve low pressure chamber. The mechanism opens to 30e.

Next, the connection of the flow path between each chamber is demonstrated.
The suction port 22 is connected to a tank, and the working fluid in the tank is supplied to the vane chamber 18 through the suction port 22. On the other hand, the discharge port 21 is connected via a pressure chamber 26 to a discharge passage 38 connected to an external device (load) and a high-pressure introduction path 73 connected to the valve high-pressure chamber 37.

  A metering orifice 23 is provided in the discharge passage 38. As an external device (working fluid utilization device) to which the hydraulic fluid is supplied, there is a device such as a power cylinder, for example. More specifically, there is a power steering device of a vehicle, a CVT (Continuously Variable Transmission), or the like. Can be mentioned.

  The high pressure introduction path 73 is a flow path connecting the discharge port 21 and the valve high pressure chamber 37. In the middle of the high-pressure introduction path 73, a branch path 75 connected to a tank maintained at atmospheric pressure is connected. A restriction (second restriction part) 60 is provided in the branch passage 75. The high pressure side of the branch passage 75 in the present embodiment is connected in the middle of the high pressure introduction path 73, but may be connected to the valve high pressure chamber 37. Further, the low pressure side of the branch passage 75 in the present embodiment is connected to the tank, but if connected to a region (low pressure region) maintained at about atmospheric pressure, such as the suction port 22 or the valve low pressure chamber 30e. good.

  A variable damper orifice (first throttle portion) 20 is provided on the high pressure introduction path 73 at a position closer to the discharge port 21 than the connection point with the branch passage 75. The variable damper orifice 20 increases the flow path area as the cam ring 15 moves in the direction in which the inherent discharge amount of the pump decreases (that is, as the eccentric amount of the cam ring 15 decreases). That is, the flow path area of the variable damper orifice 20 is small when the eccentric amount of the cam ring 15 is large (that is, when the cam ring 15 is located in the left direction in FIG. 1), and when the eccentric amount of the cam ring 15 is small (that is, When the cam ring 15 is positioned in the right direction in FIG.

  The intermediate pressure introduction path 38 a is a flow path connecting the downstream side of the metering orifice 23 in the discharge path 38 and the valve intermediate pressure chamber 36. A pilot orifice (fourth throttle) 24 is provided in the intermediate pressure introduction path 38a.

  Next, the operation of the variable displacement vane pump configured as described above will be described.

  When a rotational driving force is input from the drive shaft 13, the vane 14 together with the rotor 11 is rotated while being pressed against the cam ring 15, and the volume of the vane chamber 18 is increased or decreased. In the section where the volume increases, the pressure in the vane chamber 18 decreases, and the working fluid is sucked from the suction port 22. The hydraulic fluid sucked from the suction port 22 is pressurized as the volume of the vane chamber 18 decreases in a section not connected to either the suction port 22 or the discharge port 21. The working fluid thus pressurized is guided to the pressure chamber 26 via the discharge port 21 as the volume of the vane chamber 18 decreases.

  When the number of rotations of the pump (rotor 11) is low, the flow rate of the working fluid passing through the metering orifice 23 is small, so the pressure difference before and after the metering orifice 23 is small, and both ends of the control valve 30 (valve high pressure chamber 37 and The pressure difference in the valve intermediate pressure chamber 36) is also small. Therefore, the force generated by the pressure difference between both ends of the control valve 30 (the rightward force in FIG. 1) is smaller than the force of the spring 30c (the leftward force in FIG. 1), and the control valve 30 is kept closed. Accordingly, since the first fluid pressure chamber 40 is connected to the valve low pressure chamber 30 e via the valve hole 33, the cam ring 15 is held in the maximum eccentric state by the force of the spring 17. Thereby, since the specific discharge amount of the pump does not change, the discharge amount increases in proportion to the rotation speed of the rotor 11.

  As the pump speed increases and the discharge rate increases, the pressure loss at the metering orifice 23 increases. As a result, the pressure difference between both ends of the control valve 30 into which the pressure before and after the metering orifice 23 is introduced increases, so that the rightward force acting on the control valve 30 overcomes the leftward force of the spring 30c, and the control valve 30 is controlled. The valve 30 moves to the right in FIG. As a result, the valve high pressure chamber 37 and the valve hole 33 communicate with each other, the working fluid downstream of the variable damper orifice 20 is guided to the first fluid pressure chamber 40, and the cam ring 15 is shaken in a direction to reduce the eccentric amount of the cam ring 15. To reduce the fixed discharge rate of the pump.

  At this time, since the control valve 30 moves so that the spring force by the spring 30c and the force due to the pressure difference between both ends of the control valve 30 are balanced, the pressure difference between both ends of the control valve 30 does not change greatly. In addition, if the pressure is constant, the flow rates of the variable damper orifice 20 and the throttle (second throttle part) 60 do not change significantly.

  By the way, the discharge amount of the discharge passage 38 is mainly determined by the flow rate of the metering orifice 23. The flow rate of the metering orifice 23 is determined by the pressure difference before and after the metering orifice 23. Here, the pressure difference before and after the metering orifice 23 is firstly equal to the pressure difference between the discharge port 21 and the external device (the most downstream side of the discharge passage 38), and secondly, the variable damper orifice 20 It is equal to the sum of the pressure difference between the front and rear and the pressure difference acting on both ends of the control valve 30 in consideration of the force by the spring 30c.

  Here, since the flow rate through the variable damper orifice 20 is substantially the same regardless of the rotational speed, the pressure difference across the variable damper orifice 20 becomes small if the flow path area of the variable damper orifice 20 is large. Therefore, the variable damper orifice 20 is increased by increasing the flow passage area of the variable damper orifice 20 as the cam ring 15 moves in the direction in which the specific discharge amount decreases (the direction in which the eccentric amount decreases) as in the present embodiment. If the pressure difference before and after is reduced, the pressure difference across the metering orifice 23 is also reduced, so that the pump discharge rate can be reduced even when the rotational speed is increased.

  Next, the technique of Patent Document 1 (hereinafter referred to as a comparative example) that reduces the discharge amount by changing the flow area of the orifice provided in the middle of the discharge passage based on the movement of the cam ring, and the present embodiment By comparing these, the effect of the present embodiment will be described.

  In the present embodiment, the variable damper orifice 20 to be controlled by the flow path area is provided on the high-pressure introduction path 73, whereas the orifice to be controlled by the comparative example is provided on the discharge passage. (In other words, this corresponds to the metering orifice 23 on the discharge passage 38 in the present embodiment). Here, when comparing the pressure difference between the two, the pressure difference of the variable damper orifice 20 according to the present embodiment is always smaller than the pressure difference of the orifice of the comparative example. Therefore, the present embodiment controls the flow passage area of the throttle with a small flow rate, so that the discharge amount of the pump can be greatly reduced with a smaller area change than the comparative example. Therefore, according to the present embodiment, the pump discharge amount can be greatly reduced even when the rotational speed is increased, so that energy saving can be achieved.

FIG. 3 is a diagram showing the relationship between the rotational speed of the pump and the discharge amount in the present embodiment.
As shown in this figure, according to the variable displacement vane pump according to the present embodiment, the capacity per rotation is a fixed capacity region at a low rotation speed, and the discharge amount is increased in proportion to the rotation speed. In the variable capacity region, which is the swing region of the cam ring 15, it is possible to obtain a flow-down characteristic that can greatly reduce the discharge amount as the rotational speed increases.

  Incidentally, the variable displacement vane pump of the present embodiment includes a branch passage 75 that communicates the valve high-pressure chamber 37 and the tank, and the branch passage 75 is provided with a throttle 60. The throttle 60 is formed so that the amount of hydraulic fluid leakage increases when the pressure or temperature of the hydraulic fluid in the branch passage 75 is high and the viscosity is low. For example, the throttle 60 is formed by an annular throttle or the like. That is, the diaphragm 60 in the present embodiment functions as a pressure or temperature sensitive choke.

  FIG. 4 is a diagram showing the relationship between the rotation speed of the pump and the discharge amount when a pressure or temperature change occurs in the present embodiment. When the throttle 60 is provided as described above, as shown in FIG. 4, the leakage amount of the throttle 60 increases at a high pressure or a high temperature, and the flow rate of the variable damper orifice 20 increases. The discharge amount can be increased. Therefore, according to the present embodiment, when the pressure or temperature is high, the discharge amount of the pump can be increased accordingly. Therefore, the discharge amount of the pump can be increased only when necessary, and the minimum discharge amount can be suppressed in other cases, so that further energy saving is possible. For example, in the power steering device, the required flow rate increases as the pressure or temperature rises. Therefore, by using this embodiment, the discharge amount can be adjusted according to the pressure or temperature change.

  In the above embodiment, the pressure or temperature sensitive choke is configured by the throttle 60 provided in the branch passage 75. However, the valve high pressure chamber 37 communicates with the valve low pressure chamber 30e through the space between the spool hole 30a and the spool 30b. An annular gap may be used as a throttle to form a pressure or temperature sensitive choke. Alternatively, a passage communicating with the tank may be connected to the high-pressure introduction passage 73, and the throttle 60 may be provided in the separately provided passage.

  Next, a second embodiment of the present invention will be described. The present embodiment shows a specific structural example of the variable damper orifice 20 in the first embodiment.

  FIG. 5 is a front view of the variable displacement vane pump according to the second embodiment of the present invention, in which a partial cross section is taken during low rotation. 6 is an enlarged view of the periphery of the variable damper orifice in FIG. 5, FIG. 7 is an AA sectional view in FIGS. 5 and 6, and FIG. 8 is a CC sectional view in FIGS. FIG. 9 is an enlarged view of the periphery of the variable damper orifice during high-speed rotation, and FIG. 10 is a cross-sectional view taken along line AA in FIG. In addition, the same code | symbol is attached | subjected to the same part as the previous figure, and description is abbreviate | omitted (a later figure is handled similarly).

  The variable damper orifice 20 shown in these drawings is formed between the cam ring 15 and the pressure plate 27, and includes a cam ring groove 20a and a discharge groove 20b.

  The cam ring groove 20a is a groove provided in a concave shape in the circumferential direction of the cam ring 15 on one end surface in the axial direction of the cam ring 15, and as shown in FIGS. Move up. The cam ring groove 20 a communicates with the oil passage 52 provided in the pressure plate 27 regardless of the position of the cam ring 15. The oil passage 52 communicates with a hydraulic chamber 53 (see FIG. 8) provided in the front body 10, and the hydraulic chamber 53 communicates with the valve high pressure chamber 37. That is, the oil passage 52 and the oil passage 53 are part of a high-pressure introduction passage 73 that connects the discharge port 21 and the valve high-pressure chamber 37.

  The discharge groove 20b is a groove provided in a portion of the pump housing 71 facing the cam ring groove 20a (that is, the discharge port 21 side of the pressure plate 27), and the discharge port 21 in the portion where the vane chamber 18 has the maximum capacity. The groove protrudes from the rotor 11 (or the cam ring 15) to the outside in the radial direction. That is, the discharge groove 20 b communicates with the discharge port 21.

  Further, as shown in FIGS. 6 and 7 and the like, the width of the discharge groove 20b becomes smaller toward the tip portion located on the radially outer side of the rotor 11 (or the cam ring 15). When the discharge groove 20b is formed in this way, when the eccentric amount of the cam ring 15 is maximum, the area of the flow path formed by overlapping the discharge groove 20b and the groove 20a of the cam ring 15 can be minimized (FIG. 6, FIG. 6). (See FIG. 7). The area of the flow path can be increased as the cam ring 15 moves from the position in the direction in which the eccentric amount decreases (in the direction in which the pump's inherent discharge amount decreases) (see FIGS. 9 and 10). That is, the flow path area formed by the discharge groove 20 b together with the cam ring groove 20 a can be variably controlled according to the amount of eccentricity of the cam ring 15.

  According to the variable displacement vane pump configured as described above, the variable damper orifice 20 can be formed with a simple structure using only the axial end face of the cam ring 15 and the pump housing facing the cam ring 15. Therefore, according to the variable damper orifice 20 configured as described above, it is possible to obtain a variable displacement pump with a simple structure and a large discharge amount variation range.

  Incidentally, in the above-described embodiment, the discharge groove 20 b and the oil passage 52 provided in the pressure plate 27 are provided at different positions in the circumferential direction of the cam ring 15. When the discharge groove 20b and the oil passage 52 are offset in the circumferential direction of the cam ring 15 as described above, the variable damper orifice 20 as described above can be formed even when the radial width of the cam ring 15 is small.

In the above description, the discharge groove 20b and the oil passage 52 are offset in the circumferential direction of the cam ring 15, but the variable damper orifice 20 may be provided as described below.
FIG. 11 is an enlarged view around a variable damper orifice in a variable displacement vane pump according to a third embodiment of the present invention, and FIG. 12 is a cross-sectional view taken along line AA in FIG.

  The variable damper orifice 20 shown in this figure is different from the second embodiment in that the oil passage 52 is provided in the pressure plate 27, whereas the discharge groove 20 b is provided in the rear cover 19. That is, the discharge groove 20 b is provided in a portion (rear cover 19) on the pump housing 71 that is opposed to the end surface on one axial side of the cam ring 15, and the oil passage 52 is provided on the pump housing 71. It is a part, and is provided in the part (pressure plate 27) with which the end surface of the axial direction one side in the cam ring 15 opposes.

  In addition, the cam ring groove 20a in the present embodiment is provided in a groove 201 provided in a concave shape with respect to the end surface on the rear cover 19 side in the cam ring 15 and provided in a concave shape on the end surface on the pressure plate 27 side in the cam ring 15. A groove 203 communicating with the passage 52 and a passage 202 communicating the groove 201 and the groove 203 in the cam ring 15 are provided.

  Even when the variable damper orifice 20 is formed as described above, the variable damper orifice 20b and the oil passage 52 are offset even in the circumferential direction of the cam ring 15 even when the radial width of the cam ring 15 is small. 20 can be formed. That is, the present embodiment has an advantage in that the same effect can be obtained even when the oil passage 52 and the groove 201 are not arranged offset as compared with the second embodiment.

  Next, a fourth embodiment of the present invention will be described.

  FIG. 13: is the front view which took the partial cross section at the time of low rotation in the variable displacement vane pump which concerns on the 4th Embodiment of this invention.

  This embodiment corresponds to the variable damper orifice 20 in the first embodiment as a fixed orifice and the restrictor 60 as a variable restrictor. That is, the variable displacement vane pump of the present embodiment shown in FIG. 13 has a damper orifice (first throttle portion) 20A in which the flow area is fixed and the flow area in accordance with the change in the specific discharge amount of the pump. A variable aperture (second aperture) 60A in which the angle changes is provided.

  Contrary to the variable damper orifice 20 in the first embodiment, the variable throttle 60A flows as the cam ring 15 moves in the direction in which the pump's inherent discharge amount increases (that is, the eccentric amount of the cam ring 15 increases). The path area is configured to increase, and the channel area is decreased as the cam ring 15 moves in a direction in which the inherent discharge amount decreases (that is, the eccentric amount of the cam ring 15 decreases). .

Here, the operation of the variable displacement vane pump configured as described above will be described.
When the pump rotation speed increases and the discharge rate increases, the pressure loss at the metering orifice 23 increases, and the rightward force generated by the pressure difference across the control valve 30 overcomes the leftward force of the spring 30c. The control valve 30 moves to the right in FIG. When the control valve 30 is thus opened, the hydraulic fluid downstream of the damper orifice 20 </ b> A is guided to the first fluid pressure chamber 40 through the valve high pressure chamber 37. The hydraulic fluid introduced into the first fluid pressure chamber 40 in this way swings the cam ring 15 in a direction that reduces the eccentricity of the cam ring 15 and reduces the inherent discharge amount of the pump.

  At this time, since the control valve 30 moves so that the spring force by the spring 30c and the force due to the pressure difference between both ends of the control valve 30 are balanced, the pressure difference between both ends of the control valve 30 does not change greatly. Therefore, the pressure in the valve high-pressure chamber 37 is kept substantially constant, and the pressure difference across the variable throttle 60A is kept almost constant.

  As described above, when the pressure difference between the front and rear of the variable throttle 60A is kept constant, the flow rate passing through the variable throttle 60A decreases when the flow path area is reduced. By the way, generally, if the flow rate through the orifice (throttle portion) decreases, the pressure difference across the orifice decreases. Therefore, when the flow rate through the variable throttle 60A is reduced as described above, the pressure difference across the damper orifice 20 is reduced. When the pressure difference across the damper orifice 20 is reduced in this way, the pressure difference across the metering orifice 23 is also reduced, so that the pump discharge rate can be reduced.

  Therefore, if the flow rate through the variable throttle 60A is reduced by reducing the flow area of the variable throttle 60A as the cam ring 15 moves in the direction in which the specific discharge amount decreases as in the present embodiment, the metering Since the pressure difference between the front and rear of the orifice 23 is also reduced, the discharge amount of the pump can be reduced even when the rotational speed is increased as in the first embodiment.

  Next, a fifth embodiment of the present invention will be described.

  FIG. 14: is the front view which took the partial cross section at the time of low rotation in the variable displacement vane pump which concerns on the 5th Embodiment of this invention.

  The variable displacement vane pump of this embodiment shown in this figure corresponds to the first embodiment in which the branch passage 75 and the throttle 60 are omitted and a bypass passage 77 and a bypass orifice 51 are added.

  The bypass passage 77 branches from the high pressure introduction passage 73 and connects to the intermediate pressure introduction passage 38a in order to bypass the control valve 30. A connection point between the bypass passage 77 and the high-pressure introduction passage 73 is located downstream of the variable damper orifice (first throttle portion) 20. The upstream side of the bypass passage 77 may be connected to the valve high pressure chamber 37. On the other hand, the connection point between the bypass passage 77 and the intermediate pressure introduction passage 38 a is located on the upstream side of the pilot orifice (fourth throttle portion) 24. That is, the pilot orifice 24 is provided on the downstream side of the connection point with the bypass passage 77 on the intermediate pressure introduction passage 38a. The downstream side of the bypass passage 77 may be connected to the valve intermediate pressure chamber 36.

  The bypass orifice (third throttle portion) 51 has a fixed flow path area and is provided in the bypass passage 77.

  In the variable displacement vane pump configured as described above, when the rotation speed of the pump increases and the discharge amount increases, the control valve 30 is opened, and the working fluid downstream of the variable damper orifice 20 becomes the first fluid. Guided to the pressure chamber 40. The hydraulic fluid introduced into the first fluid pressure chamber 40 in this way swings the cam ring 15 in a direction that reduces the eccentricity of the cam ring 15 and reduces the inherent discharge amount of the pump.

  At this time, since the control valve 30 moves so that the spring force by the spring 30c and the force due to the pressure difference between both ends of the control valve 30 are balanced, the pressure difference between both ends of the control valve 30 does not change greatly. Accordingly, since the pressure difference before and after the bypass orifice 51 does not change, the flow rate through the bypass orifice 51 is kept substantially constant regardless of the rotational speed.

  By the way, the discharge amount of the discharge passage 38 is the sum of the flow rate through the bypass orifice 51 and the flow rate through the metering orifice 23. However, since the flow rate through the bypass orifice 51 is constant as described above, the discharge amount of the discharge passage 38 is determined by the flow rate of the metering orifice 23. The flow rate through the metering orifice 23 is determined by the pressure difference before and after the metering orifice 23. Here, the pressure difference before and after the metering orifice 23 is firstly equal to the pressure difference between the discharge port 21 and the external device (the most downstream side of the discharge passage 38), and secondly, the variable damper orifice 20 It is equal to the sum of the front-rear pressure difference, the front-rear pressure difference of the bypass orifice 51, and the front-rear pressure difference of the pilot orifice 24.

  The flow rate of the bypass orifice 51 and the flow rate of the variable damper orifice 20 are substantially the same except for leakage, and are substantially constant regardless of the rotational speed. Therefore, if the flow path area of the variable damper orifice 20 is large, the pressure difference across the variable damper orifice 20 is small. Thus, if the pressure difference across the variable damper orifice 20 becomes small, the sum of the pressure difference across the variable damper orifice 20, the pressure difference across the bypass orifice 51, and the pressure difference across the pilot orifice 24, that is, the metering orifice 23 Since the pressure difference between before and after becomes smaller, the discharge amount of the pump is reduced.

  Therefore, if the flow passage area of the variable damper orifice 20 is increased as the cam ring 15 moves in the direction in which the specific discharge amount decreases as in the present embodiment, the rotational speed increases as in the first embodiment. In this case, the discharge amount of the pump can be reduced.

  Next, a sixth embodiment of the present invention will be described. The present embodiment shows a specific structural example of the variable damper orifice 20 in the fifth embodiment.

  FIG. 15 is a front view of a variable displacement vane pump according to a sixth embodiment of the present invention, with a partial cross section taken during low rotation, and FIG. 16 is a cross-sectional view taken along line AA in FIG.

  The variable damper orifice 20 shown in these drawings is formed by a hole 20d provided in a portion (pressure plate 27) on the pump housing 71 and facing the axial end surface of the cam ring 15.

  The hole 20d communicates with a hydraulic chamber 53 (see FIG. 16) communicating with the valve high pressure chamber 37, and is a portion on the second fluid pressure chamber 41 side in the cam ring 15, and the eccentric amount of the cam ring 15 is reduced. The vane chamber 18 is provided in a portion where the volume increases. As shown in FIG. 15, the opening of the hole 20 d in the pressure plate 27 extends in the radial direction of the cam ring 15. The opening of the hole 20 d in the present embodiment is formed in an elliptical shape, and the long axis of the ellipse extends in the radial direction of the rotor 11. As a result, the area of the flow path formed by the communication between the hole 20 d and the vane chamber 18 varies according to the amount of eccentricity of the cam ring 15. More specifically, the hole 20d is formed so that the flow path area decreases as the eccentric amount of the cam ring 15 increases, and the flow path area increases as the eccentric amount of the cam ring 15 decreases. Yes.

  If the variable damper orifice 20 is formed in this way, it is not necessary to process the cam ring 15 as in the second embodiment, so that the structure of the pump can be simplified.

  Next, a seventh embodiment of the present invention will be described. The present embodiment shows another specific structural example of the variable damper orifice 20 in the fifth embodiment.

  FIG. 17: is the front view which took the partial cross section at the time of low rotation in the variable displacement vane pump which concerns on the 7th Embodiment of this invention.

  In the present embodiment, one or more holes 20e provided in the pressure plate 27 are provided in place of the ejection grooves 20b in the second embodiment (in this embodiment, the holes 20e as shown in FIG. 17). Is two). The hole 20e communicates with the pressure chamber 26 from which the hydraulic fluid is discharged from the discharge port 21, and supplies the hydraulic fluid to the cam ring groove 20a. Further, the hole 20e is formed so that the flow path area increases as the eccentric amount of the cam ring 15 decreases, and the variable displacement vane pump of this embodiment operates in the same manner as that of the second embodiment. .

  According to the present embodiment configured as described above, the relationship between the amount of eccentricity of the cam ring 15 and the flow path area can be freely changed depending on the position and size of the one or more holes 20e. The variable damper orifice 20 can be provided. In addition, even if the hole 20d in the sixth embodiment is formed with a plurality of holes like the hole 20e in the present embodiment, the same effect as in the present embodiment can be obtained.

  Next, an eighth embodiment of the present invention will be described. The present embodiment shows still another specific structural example of the variable damper orifice 20 in the fifth embodiment.

  FIG. 18 is a front view of a variable displacement vane pump according to an eighth embodiment of the present invention, with a partial cross section taken at low speed.

  In the present embodiment, the variable damper orifice 20 is configured using a plug 61, a plunger 62, a hole 66 provided in the plug 61, and the like. The plug 61 is fitted in a plug hole 61a formed in the pump housing 71 (front body 10). The plunger 62 is slidably provided in the plug 61, and is biased by the coil spring 62b so that the eccentric amount of the cam ring 15 is reduced. Thereby, the plunger 62 slides in the plug 61 in conjunction with the movement of the cam ring 15. The hole 66 is a flow path that connects the discharge port 21 and the valve high pressure chamber 37, and the flow path area is variably controlled according to the amount of movement of the plunger 62. The hole 66 in the present embodiment is formed so that the flow path area increases as the eccentric amount of the cam ring 15 decreases (that is, the plunger 62 moves to the right in FIG. 18). The hole 66 may be composed of a plurality of small holes.

  In the present embodiment, the hydraulic fluid discharged from the discharge port 21 is introduced into the first space 64 formed by the large diameter portion of the plug hole 61a and the plug 61, and passes through the hole 63 provided in the plug 61. Then, it is introduced into an annular groove 62 a formed on the outer periphery of the plunger 62. The hydraulic fluid introduced into the annular groove 62a is a second space formed by the middle diameter portion of the plug hole 61a and the plug 61 through the hole 66 whose flow area is variably controlled according to the amount of eccentricity of the cam ring 15. 65 and is introduced into the high-pressure introduction path 73.

  According to the present embodiment configured as described above, since the flow passage area can be variably controlled using the plunger 62 that moves in conjunction with the cam ring 15, a large control range of the pump discharge amount can be secured. It is.

  In the description of the sixth to eighth embodiments, the structure of the variable damper orifice 20 in the fifth embodiment has been described as an example. However, the structure described here is the same as the first embodiment. Of course, the present invention can also be applied to the embodiment.

  Next, a ninth embodiment of the present invention will be described. The present embodiment shows the flow area control of the variable damper orifice 20 in the fifth embodiment.

  FIG. 19 is a diagram showing the relationship between the eccentric amount of the cam ring and the flow path area of the variable damper orifice in the variable displacement vane pump according to the eighth embodiment of the present invention, and FIG. 20 shows the relationship between the eighth embodiment of the present invention and FIG. It is a relationship diagram of the rotation speed and the discharge amount in such a variable displacement vane pump.

  In the first and fifth embodiments described above, the variable damper orifice 20 is configured so that the flow path area increases as the eccentric amount of the cam ring 15 decreases. On the other hand, in the present embodiment, as shown in FIG. 19, after the eccentric amount (movement amount) of the cam ring 15 becomes smaller than the set value D1, it is variable so that the flow path area is kept constant. A damper orifice 20 is configured. When the variable damper orifice 20 is formed in this way, as shown in FIG. 20, the discharge amount can be made constant in a high rotation region where the eccentric amount exceeds the rotation speed R1 reaching D1. Thereby, a minimum flow rate can be discharged uniformly in the high rotation range.

  Note that, as in the fourth embodiment, when the variable throttle 60A is provided in which the flow path area increases as the eccentric amount of the cam ring 15 increases, the eccentric amount ( Needless to say, the variable throttle may be configured so that the flow path area is kept constant after the (movement amount) becomes larger than the set value D2.

  Next, a tenth embodiment of the present invention will be described.

  FIG. 21 is a front view of the variable displacement vane pump according to the tenth embodiment of the present invention, with a partial cross section taken during low rotation.

  The present embodiment corresponds to the fifth embodiment in which the variable damper orifice 20 is a fixed orifice and the bypass orifice 51 is a variable orifice. That is, the variable displacement vane pump of the present embodiment shown in FIG. 21 has a damper orifice (first throttle) 20A having a fixed flow path area and a flow path area that changes in accordance with a change in the specific discharge amount of the pump. A variable bypass orifice (third throttle) 51A is provided.

  Contrary to the variable damper orifice 20 in the fifth embodiment, the variable bypass orifice 51A moves as the cam ring 15 moves in the direction in which the inherent discharge amount of the pump increases (that is, the eccentric amount of the cam ring 15 increases). The channel area is configured to increase, and the channel area is decreased as the cam ring 15 moves in a direction in which the specific discharge amount decreases (that is, the eccentric amount of the cam ring 15 decreases). Yes. Here, an example of a specific configuration of the variable bypass orifice 51A will be described.

  22 is a diagram showing an example of a specific configuration of the variable bypass orifice 51A in FIG. 21, and FIG. 23 is a cross-sectional view taken along the line AA in FIG.

  The variable bypass orifice 51A shown in these drawings is composed of a cam ring groove 51b provided on the end face of the cam ring 15 on the pressure plate 27 side, and an oil passage 51c provided in the pressure plate 27 and communicating with the cam ring groove 51b. .

  The cam ring groove 51 b is a groove provided in a concave shape in the circumferential direction of the cam ring 15, and moves along with the rocking of the cam ring 15 above the oil passage 51 c opened in the pressure plate 27. As a result, the area of the flow path (throttle) formed by overlapping the cam ring groove 51 b and the oil path 51 c varies as the cam ring 15 swings. The overlapping portion of the cam ring groove 51b and the oil passage 51c, that is, the flow passage area of the variable bypass orifice 51A is configured to increase as the eccentric amount of the cam ring 15 increases and decrease as the eccentric amount decreases.

  The cam ring groove 51 b communicates with an oil passage 51 d provided in the pressure plate 27 regardless of the position of the cam ring 15. The oil passage 51d communicates with a hydraulic chamber 39c (see FIG. 23) provided in the front body, and the hydraulic chamber 39c communicates with the valve high-pressure chamber 37. That is, the oil passage 51 d and the hydraulic chamber 39 c are part of the bypass passage 77.

  The oil passage 51c is provided in a portion of the pressure plate 27 where the cam ring groove 51b faces, and communicates with a hydraulic chamber 39b (see FIG. 23) provided in the front body 10. The hydraulic chamber 39 b communicates with the valve intermediate pressure chamber 36 and communicates with the hydraulic chamber 38 b (see FIG. 23) via the pilot orifice 24. That is, the hydraulic chamber 39b is a part of the intermediate pressure introduction path 38a. The hydraulic chamber 38b is provided in the front body 10 and is connected to an external device (load).

  In the variable displacement vane pump configured as described above, when the rotation speed of the pump increases and the discharge amount increases, the control valve 30 is opened, and the working fluid downstream of the variable damper orifice 20 becomes the first fluid. Guided to the pressure chamber 40. The hydraulic fluid introduced into the first fluid pressure chamber 40 in this way swings the cam ring 15 in a direction that reduces the eccentricity of the cam ring 15 and reduces the inherent discharge amount of the pump.

  At this time, since the control valve 30 moves so that the spring force by the spring 30c and the force due to the pressure difference between both ends of the control valve 30 are balanced, the pressure difference between both ends of the control valve 30 does not change greatly. Therefore, since the pressure difference across the variable bypass orifice 51A is equal to the pressure difference across the control valve 30, the pressure difference across the variable bypass orifice 51A is held substantially constant. Therefore, if the flow path area of the variable bypass orifice 51A is reduced, the flow rate through the variable bypass orifice 51A is reduced.

  Here, the flow rate through the damper orifice 20A and the pilot orifice 24 is substantially the same as the flow rate through the variable bypass orifice 51A, except for leakage. By the way, generally, if the flow rate through the orifice decreases, the pressure difference across the orifice decreases. Accordingly, when the flow rate through the variable bypass orifice 51A is reduced, the pressure difference between the damper orifice 20A and the pilot orifice 24 is reduced. As a result, the sum of the pressure difference across the damper orifice 20A, the pressure difference across the variable bypass orifice 51A, and the pressure difference across the pilot orifice 24, that is, the pressure difference across the metering orifice 23 is reduced. The flow rate can be reduced. Therefore, also in the present embodiment, the discharge rate of the pump can be reduced as in the first embodiment.

  Next, an eleventh embodiment of the present invention will be described.

  FIG. 24 is a front view of the variable displacement vane pump according to the eleventh embodiment of the present invention, taking a partial cross section during low rotation, and FIG. 25 shows a cross section taken along the line AA in FIG.

  This embodiment corresponds to the fifth embodiment in which the variable damper orifice 20 is a fixed orifice and the pilot orifice 24 is a variable orifice. That is, the variable displacement vane pump of the present embodiment shown in these drawings includes a pilot orifice (fourth restrictor) 24A whose flow area changes in accordance with a change in the pump's inherent discharge amount. As with the variable damper orifice 20 in the first embodiment, the pilot orifice 24A flows as the cam ring 15 moves in a direction in which the pump's inherent discharge amount decreases (that is, as the eccentric amount of the cam ring 15 decreases). The road area is increased.

  The variable pilot orifice 24A is formed in a structure as shown in FIGS. 24 and 25, for example. In these drawings, the variable pilot orifice 24A is composed of a cam ring groove 24a provided on the end face of the cam ring 15 on the pressure plate 27 side, and an oil passage 24b provided in the pressure plate 27 and communicating with the cam ring groove 24a. .

  The cam ring groove 24 a is a groove provided in a concave shape in the circumferential direction of the cam ring 15, and moves along with the rocking of the cam ring 15 above the oil passage 24 b opened in the pressure plate 27. Thereby, the area of the flow path (throttle) formed by overlapping the cam ring groove 24 a and the oil path 24 b varies as the cam ring 15 swings. The overlapping portion of the cam ring groove 24a and the oil passage 24b, that is, the flow passage area of the variable pilot orifice 24A is configured to decrease as the eccentric amount of the cam ring 15 increases and increase as the eccentric amount decreases. The cam ring groove 51 b communicates with an oil passage 39 a provided in the pressure plate 27 regardless of the position of the cam ring 15. The oil passage 39a communicates with the hydraulic chamber 39b.

  The oil passage 24b is provided in a portion of the pressure plate 27 where the cam ring groove 24a is opposed, and communicates with the hydraulic chamber 38b (see FIG. 25).

  In the variable displacement vane pump configured as described above, when the rotation speed of the pump increases and the discharge amount increases, the control valve 30 is opened, and the working fluid downstream of the variable damper orifice 20 becomes the first fluid. Guided to the pressure chamber 40. The hydraulic fluid introduced into the first fluid pressure chamber 40 in this way swings the cam ring 15 in a direction that reduces the eccentricity of the cam ring 15 and reduces the inherent discharge amount of the pump.

  At this time, since the control valve 30 moves so that the spring force by the spring 30c and the force due to the pressure difference between both ends of the control valve 30 are balanced, the pressure difference between both ends of the control valve 30 does not change greatly. Accordingly, since the pressure difference before and after the bypass orifice 51 does not change, the flow rate through the bypass orifice 51 is kept substantially constant regardless of the rotational speed.

  By the way, the discharge amount of the discharge passage 38 is the sum of the flow rate through the bypass orifice 51 and the flow rate through the metering orifice 23. However, since the flow rate through the bypass orifice 51 is constant as described above, the discharge amount of the discharge passage 38 is determined by the flow rate of the metering orifice 23. The flow rate through the metering orifice 23 is determined by the pressure difference before and after the metering orifice 23. Here, the pressure difference before and after the metering orifice 23 is firstly equal to the pressure difference between the discharge port 21 and the external device (the most downstream side of the discharge passage 38), and secondly, the pressure difference before and after the damper orifice 20A. This is equal to the sum of the pressure difference, the pressure difference across the bypass orifice 51, and the pressure difference across the variable pilot orifice 24A.

  The flow rate of the bypass orifice 51 and the flow rate of the variable pilot orifice 24A are substantially the same except for leakage, and are substantially constant regardless of the rotational speed. Therefore, if the flow path area of the variable pilot orifice 24A is large, the pressure difference across the variable pilot orifice 24A is small. Thus, when the front-rear pressure difference of the variable pilot orifice 24A is reduced, the sum of the front-rear pressure difference of the damper orifice 20, the front-rear pressure difference of the bypass orifice 51, and the front-rear pressure difference of the variable pilot orifice 24A, ie, the metering orifice Since the front-rear pressure difference of 23 becomes small, the discharge flow rate of the pump can be reduced. Therefore, also in the present embodiment, the discharge rate of the pump can be reduced as in the first embodiment.

  Next, a twelfth embodiment of the present invention will be described. This embodiment corresponds to the fifth embodiment in which the metering orifice 23 is a variable orifice (variable metering orifice 23A).

  FIG. 26 is a front view of a variable displacement vane pump according to a twelfth embodiment of the present invention, with a partial cross section taken during low rotation.

  The variable displacement vane pump shown in this figure includes a cam ring groove 23a provided on the end face of the cam ring 15 on the pressure plate 27 side, and an oil passage 23b provided in the pressure plate 27 through the cam ring groove 23a and the pressure chamber 26. I have. The variable metering orifice 23A is formed between the cam ring groove 23a and the oil passage 23b, and the flow path area changes according to the movement of the cam ring 15. That is, when the eccentric amount of the cam ring 15 is large, the overlap of the oil passage 23b and the cam ring groove 23a is large, and the flow area of the variable metering orifice 23A is large, and when the eccentric amount of the cam ring 15 is small, the flow path area is large. Becomes smaller.

  With such a configuration, if the flow path area is changed between the two orifices of the variable damper orifice 20 and the variable metering orifice 23A, it is possible to secure a larger change width of the discharge amount. The variable metering orifice 23A can be combined not only with the variable damper orifice 20 but also with the variable bypass orifice 51A or with the variable pilot orifice 24A.

  Next, a thirteenth embodiment of the present invention will be described. This embodiment shows the flow area control of the variable damper orifice 20 and the variable metering orifice 23A in the twelfth embodiment.

  FIG. 27 shows an example of the relationship between the eccentric amount of the cam ring and the flow area of the variable metering orifice 23A and the variable damper orifice 20 in the variable displacement vane pump according to the thirteenth embodiment of the present invention. It is another example of the relationship between the eccentric amount of the cam ring in this Embodiment, and the flow-path area of the variable metering orifice 23A and the variable damper orifice 20. FIG. FIG. 29 is a relationship diagram between the rotation speed and the discharge amount of the variable displacement vane pump according to the present embodiment.

  In the present embodiment, the control start timings of the flow path areas in the variable damper orifice 20 and the variable metering orifice 23A are different. Specifically, as shown in FIGS. 27 and 28, a region in which the flow path area is kept constant regardless of the amount of eccentricity of the cam ring 15 is provided as in the ninth embodiment, and both orifices 20, 23A are provided. The flow path area control start timing is different. When the control start timing is shifted in this way, as shown in FIG. 29, in the variable capacity region, when the rotation speed is small, the area change is small, so the discharge amount decreases less, and as the rotation speed increases, the discharge amount decreases. The pump can have a complicated flow rate characteristic that gradually increases. Therefore, according to the present embodiment, a complicated flow rate characteristic can be obtained with a simple configuration, and a flow rate characteristic corresponding to the number of rotations can be obtained, so that more energy can be saved.

  As shown in FIG. 27, when the flow path area of the variable damper orifice 20 is controlled first, the above characteristic change can be greatly taken at the start of control. On the other hand, as shown in FIG. 28, when the flow area of the variable metering orifice 23A is controlled first, the reverse characteristics can be obtained. Further, the control of the flow area is not limited to that shown in the present embodiment, but can be changed according to the required flow characteristics.

  Next, a fourteenth embodiment of the present invention will be described.

  FIG. 30 is a front view of a variable displacement vane pump according to a fourteenth embodiment of the present invention, with a partial cross section taken during low rotation.

  The present embodiment corresponds to a configuration in which the branch passage 75 having the restriction 60 shown in the first embodiment is connected to the high-pressure introduction path 73 in the fifth embodiment. Thus, even if the branch passage 75 is attached to the one described in the fifth embodiment, the discharge amount of the pump can be increased in accordance with the increase in pressure and temperature, so that it is the same as in the first embodiment. The effect of can be obtained.

  Next, a fifteenth embodiment of the present invention will be described.

  FIG. 31 is a front view of a variable displacement vane pump according to a fifteenth embodiment of the present invention, with a partial cross section taken at low speed.

  When this embodiment is compared with the fifth embodiment, the pipe connections are different. That is, the bypass passage 77 in the present embodiment is connected to the intermediate pressure introduction passage 38 a (or the discharge passage 38) on the downstream side of the pilot orifice (fourth throttle portion) 24. In other words, the pilot orifice 24 in the present embodiment is provided on the upstream side of the connection point with the bypass passage 77 on the intermediate pressure introduction path 38a. The other configuration is the same as that of the fifth embodiment.

  In the fifth embodiment, since the flow rate through the bypass passage 77 is determined by the relationship between the flow area of the variable damper orifice 20, the bypass orifice 51, and the pilot orifice 24, the three orifices 20, 51, 24 are designed separately. I couldn't. However, in the present embodiment configured as described above, the flow path area of the pilot orifice 24 does not affect the flow of the bypass orifice 51. As a result, the flow passage area of the pilot orifice 24 can be adjusted independently, so that the relief flow rate of the relief valve 32 can be adjusted.

  In the present embodiment, the damper orifice (first throttle portion) 20 is variable as in the fifth embodiment, but the same effect can be obtained even if the bypass orifice (third throttle portion) 51 is variable. .

  Next, a sixteenth embodiment of the present invention will be described.

  FIG. 32 is a front view of the variable displacement vane pump according to the sixteenth embodiment of the present invention, with a partial cross section taken during low rotation.

  The present embodiment is different from the fifth embodiment in the connection of the pipe line and the point that the pilot orifice 24 is changed to a variable orifice (variable pilot orifice 24A) instead of the variable damper orifice 20. That is, the bypass passage 77 in the present embodiment is connected to the high-pressure introduction passage 73 (or the discharge port 21) on the upstream side of the damper orifice (first throttle portion) 20A. In other words, the damper orifice 20 </ b> A in the present embodiment is provided on the high-pressure introduction path 73 on the valve high-pressure chamber 37 side than the connection point with the bypass path 77. The other configuration is the same as that of the fifth embodiment.

  In the fifth embodiment, since the flow rate through the bypass passage 77 is determined by the relationship between the flow area of the variable damper orifice 20, the bypass orifice 51, and the pilot orifice 24, the three orifices 20, 51, 24 are designed separately. I couldn't. However, in the present embodiment configured as described above, the flow path area of the damper orifice 20 does not affect the flow of the bypass orifice 51. . Thereby, since the flow path area of the damper orifice 20 can be adjusted independently, the flow of the damper orifice 20 that affects the attenuation of the cam ring 15 can be adjusted.

  In this embodiment, the pilot orifice (fourth restrictor) 24 is variable, but the same effect can be obtained even if the bypass orifice (third restrictor) 51 is variable.

  By the way, the variable displacement vane pump described in the above embodiments can be used for a power steering device of a vehicle. The power steering device is a power cylinder that has a pair of hydraulic chambers and applies steering force to the steered wheels, a pump device that supplies hydraulic fluid to the power cylinder, and hydraulic fluid that is supplied from the pump device. A rotary valve is selectively provided to selectively supply the pair of hydraulic chambers. The variable displacement vane pump according to the present invention can be used as a pump device in this power steering device. At this time, as a drive source of the drive shaft (shaft) 13 of the variable displacement vane pump (pump device), an engine mounted on the vehicle may be used.

The front view which took the partial cross section at the time of low rotation in the variable displacement vane pump which concerns on the 1st Embodiment of this invention. AA sectional drawing in FIG. The relationship diagram of the rotation speed and discharge amount of the pump in the variable displacement vane pump according to the first embodiment of the present invention. FIG. 3 is a relationship diagram between the rotational speed of a pump and a discharge amount when a pressure or temperature change occurs in the first embodiment of the present invention. The front view which took the partial cross section at the time of low rotation in the variable displacement vane pump which concerns on the 2nd Embodiment of this invention. FIG. 6 is an enlarged view around a variable damper orifice in FIG. 5. AA sectional drawing in FIG.5 and FIG.6. CC sectional drawing in FIG.5 and FIG.6. The enlarged view of the periphery of a variable damper orifice at the time of high speed rotation in the variable displacement vane pump according to the second embodiment of the present invention. AA sectional drawing in FIG. FIG. 6 is an enlarged view around a variable damper orifice in a variable displacement vane pump according to a third embodiment of the present invention. AA sectional drawing in FIG. The front view which took the partial cross section at the time of low rotation in the variable displacement vane pump which concerns on the 4th Embodiment of this invention. The front view which took the partial cross section at the time of low rotation in the variable displacement vane pump which concerns on the 5th Embodiment of this invention. The front view which took the partial cross section at the time of low rotation in the variable displacement vane pump which concerns on the 6th Embodiment of this invention. AA sectional drawing in FIG. The front view which took the partial cross section at the time of low rotation in the variable displacement vane pump which concerns on the 7th Embodiment of this invention. The front view which took the partial cross section at the time of low rotation in the variable displacement vane pump which concerns on the 8th Embodiment of this invention. The relationship figure of the eccentric amount of the cam ring and the flow-path area of a variable damper orifice in the variable displacement vane pump which concerns on the 8th Embodiment of this invention. The relationship figure of the rotation speed and discharge amount in the variable displacement vane pump which concerns on the 8th Embodiment of this invention. The front view which took the partial cross section at the time of low rotation in the variable displacement vane pump which concerns on the 10th Embodiment of this invention. The figure which shows an example of the specific structure of 51 A of variable bypass orifices in the variable displacement vane pump which concerns on the 10th Embodiment of this invention. AA sectional drawing in FIG. The front view which took the partial cross section at the time of low rotation in the variable displacement vane pump which concerns on the 11th Embodiment of this invention. AA cross section in FIG. The front view which took the partial cross section at the time of low rotation in the variable displacement vane pump which concerns on the 12th Embodiment of this invention. The relationship figure of the eccentric amount of the cam ring and the flow-path area of the variable metering orifice 23A and the variable damper orifice 20 in the variable displacement vane pump according to the thirteenth embodiment of the present invention. Another relationship diagram between the eccentric amount of the cam ring and the flow area of the variable metering orifice 23A and the variable damper orifice 20 in the variable displacement vane pump according to the thirteenth embodiment of the present invention. The relationship figure of the rotation speed and discharge amount of the variable displacement vane pump which concerns on the 13th Embodiment of this invention. The front view which took the partial cross section at the time of low rotation in the variable displacement vane pump which concerns on the 14th Embodiment of this invention. The front view which took the partial cross section at the time of low rotation in the variable displacement vane pump which concerns on 15th Embodiment of this invention. The front view which took the partial cross section at the time of low rotation in the variable displacement vane pump which concerns on the 16th Embodiment of this invention.

10 Front body 15 Cam ring 19 Rear cover 20 Variable damper orifice (first throttle)
20A Damper orifice 20a Cam ring groove 20b Discharge groove 21 Discharge port 22 Suction port 23 Metering orifice 23A Variable metering orifice 24 Pilot orifice (fourth restrictor)
24A Variable pilot orifice 27 Pressure plate 30 Control valve 30a Spool hole 30b Spool 30d Annular groove 30e Valve low pressure chamber 32 Relief valve 33 Valve hole 36 Valve medium pressure chamber (spring chamber)
37 Valve high pressure chamber 38 Discharge passage 38a Medium pressure introduction passage 40 First fluid pressure chamber 42 Second fluid pressure chamber 51 Bypass orifice (third restrictor)
51A Variable bypass orifice 52 Oil passage 60 Restriction (second restrictor)
61 Plug 62 Plunger 66 Hole 70 Pump element accommodating portion 71 Pump housing 72 Pump element 73 High pressure introduction path 75 Branch path 77 Bypass path

Claims (15)

A variable displacement pump that supplies hydraulic fluid to external equipment,
A pump housing having a pump element housing;
A drive shaft supported by the pump housing and driven by a drive source;
An annular cam ring movably provided in the pump element accommodating portion;
A hydraulic fluid is provided in the cam ring and discharges the hydraulic fluid sucked by the rotational drive of the drive shaft, and the specific discharge amount, which is a discharge amount per rotation, is changed in accordance with a change in the eccentric amount of the cam ring with respect to the drive shaft. A pump element;
A first fluid pressure chamber provided between the pump element housing portion and the cam ring and provided on a side where the volume decreases as the intrinsic discharge amount increases;
A second fluid pressure chamber provided between the pump element housing portion and the cam ring and provided on a side where the volume increases as the intrinsic discharge amount increases;
A suction port formed in the pump housing and opening into a suction area of the pump element;
A discharge port formed in the pump housing and open to a discharge region of the pump element;
A discharge passage connecting the discharge port and the external device;
A metering orifice provided in the discharge passage;
A spool hole formed in the pump housing, a spool slidably provided in the spool hole, a valve high-pressure chamber provided on one side in the moving direction of the spool and introduced with pressure from the discharge port; A valve intermediate pressure chamber that is provided on the other side of the spool in the moving direction and into which the downstream pressure of the metering orifice is introduced, and that the spool slides in communication with the first fluid pressure chamber or the second fluid pressure chamber. And a valve hole whose flow area is variably controlled, and controls the pressure introduced into the first fluid pressure chamber or the second fluid pressure chamber as the flow area of the valve hole changes. A control valve for controlling the moving position of the cam ring;
A high-pressure introduction path connecting the discharge port and the valve high-pressure chamber;
An intermediate pressure introduction path connecting the valve intermediate pressure chamber and the downstream side of the metering orifice;
A branch passage connected to the low pressure region that is connected to the middle of the high pressure introduction path or the valve high pressure chamber and maintained at about atmospheric pressure,
On the high-pressure introduction path, a first throttle portion provided at a position closer to the discharge port than a connection point with the branch passage;
A second throttle portion provided in the branch passage,
Either the first throttle part or the second throttle part is a variable orifice that variably controls the flow path area according to the movement of the cam ring,
When the first throttle portion is a variable orifice, the variable orifice increases the flow path area as the cam ring moves in a direction in which the specific discharge amount decreases.
When the second throttle portion is a variable orifice, the variable orifice increases the flow path area as the cam ring moves in a direction in which the specific discharge amount increases. The variable displacement pump according to claim 1, wherein
The first restrictor is a variable orifice;
A variable displacement pump characterized in that the flow passage area of the variable orifice is variably controlled by an axial end face of the cam ring. The variable displacement pump according to claim 2,
The variable orifice is
A cam ring groove provided on an end surface on one axial side of the cam ring;
A discharge groove provided in the pump housing and communicating the cam ring groove with the discharge port;
The cam ring groove communicates with the high pressure introduction path via an oil path provided in the pump housing,
The variable displacement pump according to claim 1, wherein the discharge groove is formed such that a flow passage area formed together with the cam ring groove increases as the cam ring moves in a direction in which the specific discharge amount decreases. The variable displacement pump according to claim 3,
The variable displacement pump according to claim 1, wherein the discharge groove and the oil passage provided in the pump housing are provided at different positions in the circumferential direction of the cam ring. The variable displacement pump according to claim 2,
The variable orifice is configured with holes communicating the area in the cam ring is provided in a portion axial end face facing in the cam ring on the pump housing to the high-pressure introduction passage, by the said axial end face of the cam ring And
The hole is formed so that the flow passage area of the variable orifice increases as the eccentric amount of the cam ring decreases.
The variable displacement pump characterized in that the flow passage area of the variable orifice varies according to the amount of eccentricity of the cam ring .
The variable displacement pump according to claim 1, wherein
When the first throttle portion is a variable orifice, the flow path area is held constant after the amount of movement of the cam ring in a direction in which the specific discharge amount decreases exceeds a set value,
When the second restrictor is a variable orifice, the flow path area is held constant after the amount of movement of the cam ring in a direction in which the specific discharge amount increases exceeds a set value. pump. The variable displacement pump according to claim 1, wherein
The variable orifice is
A plug formed in the pump housing;
A plunger that slides in the plug in conjunction with the movement of the cam ring;
A hole provided in the plug and communicating with the discharge port and the valve high-pressure chamber;
The variable displacement pump, wherein the hole is variably controlled as the plunger slides. The variable displacement pump according to claim 1, wherein
The variable displacement pump according to claim 1, wherein the metering orifice has a flow path area that decreases as the cam ring moves in a direction in which the specific discharge amount decreases. The variable displacement pump according to claim 8,
The variable displacement pump characterized by the fact that the control start timing of the flow path area is different between the variable orifice and the metering orifice. The variable displacement pump according to claim 1, wherein
The control valve is
An annular groove provided in the circumferential direction of the central portion of the spool;
A valve low-pressure chamber provided between the annular groove and the spool hole and introduced with pressure from the suction port;
The low pressure region is the valve low pressure chamber;
The variable displacement pump, wherein the first restrictor is the variable orifice. The variable displacement pump according to claim 1, wherein
A variable displacement pump, further comprising a pressure or temperature sensitive choke that connects the high pressure introduction path or the valve high pressure chamber to a low pressure region maintained at about atmospheric pressure through a throttle portion. A variable displacement pump that supplies hydraulic fluid to external equipment,
A pump housing having a pump element housing;
A drive shaft supported by the pump housing and driven by a drive source;
An annular cam ring movably provided in the pump element accommodating portion;
A hydraulic fluid is provided in the cam ring and discharges the hydraulic fluid sucked by the rotational drive of the drive shaft, and the specific discharge amount, which is a discharge amount per rotation, is changed in accordance with a change in the eccentric amount of the cam ring with respect to the drive shaft. A pump element;
A first fluid pressure chamber provided between the pump element housing portion and the cam ring and provided on a side where the volume decreases as the intrinsic discharge amount increases;
A second fluid pressure chamber provided between the pump element housing portion and the cam ring and provided on a side where the volume increases as the intrinsic discharge amount increases;
A suction port formed in the pump housing and opening into a suction area of the pump element;
A discharge port formed in the pump housing and open to a discharge region of the pump element;
A discharge passage connecting the discharge port and the external device;
A metering orifice provided in the discharge passage;
A spool hole formed in the pump housing, a spool slidably provided in the spool hole, a valve high-pressure chamber provided on one side in the moving direction of the spool and introduced with pressure from the discharge port; A valve intermediate pressure chamber that is provided on the other side of the spool in the moving direction and into which the downstream pressure of the metering orifice is introduced, and that the spool slides in communication with the first fluid pressure chamber or the second fluid pressure chamber. And a valve hole whose flow area is variably controlled, and controls the pressure introduced into the first fluid pressure chamber or the second fluid pressure chamber as the flow area of the valve hole changes. A control valve for controlling the moving position of the cam ring;
A high-pressure introduction path connecting the discharge port and the valve high-pressure chamber;
An intermediate pressure introduction path connecting the valve intermediate pressure chamber and the downstream side of the metering orifice;
A bypass passage branching from the high pressure introduction path to bypass the control valve and connected to the intermediate pressure introduction path;
On the high-pressure introduction path, a first throttle portion provided at a position closer to the discharge port than a connection point with the bypass passage;
A third throttle provided in the bypass passage;
A fourth throttle part provided on the downstream side of the connection point with the bypass passage on the intermediate pressure introduction path;
Any one of the first restrictor, the third restrictor, and the fourth restrictor is a variable orifice that variably controls the flow passage area according to the movement of the cam ring,
When the first throttle part or the fourth throttle part is a variable orifice, the variable orifice increases the flow area as the cam ring moves in a direction in which the specific discharge amount decreases.
In the case where the third restrictor is a variable orifice, the variable orifice increases the flow path area as the cam ring moves in a direction in which the specific discharge amount increases. The variable displacement pump according to claim 12,
The fourth throttle portion is provided on the upstream side of the connection point with the bypass passage on the intermediate pressure introduction path,
Either one of the first throttle part or the third throttle part is a variable orifice that variably controls the flow path area according to the movement of the cam ring,
When the first throttle portion is a variable orifice, the variable orifice increases the flow path area as the cam ring moves in a direction in which the specific discharge amount decreases.
In the case where the third restrictor is a variable orifice, the variable orifice increases the flow path area as the cam ring moves in a direction in which the specific discharge amount increases. The variable displacement pump according to claim 12,
The first throttle portion is provided on the high-pressure introduction path at a position closer to the valve high-pressure chamber than a connection point with the bypass passage,
Either the third throttle part or the fourth throttle part is a variable orifice that variably controls the flow path area according to the movement of the cam ring,
When the fourth throttle portion is a variable orifice, the variable orifice increases the flow path area as the cam ring moves in the direction in which the specific discharge amount decreases.
In the case where the third restrictor is a variable orifice, the variable orifice increases the flow path area as the cam ring moves in a direction in which the specific discharge amount increases. A power cylinder that has a pair of hydraulic chambers and applies steering force to the steered wheels, a pump device that supplies hydraulic fluid to the power cylinder, and the hydraulic fluid supplied from the pump device is used as the pair of hydraulic pressures. A power steering device comprising a rotary valve for selectively switching to a chamber,
The pump device is
A pump housing having a pump element housing;
A drive shaft supported by the pump housing and driven by a vehicle engine;
An annular cam ring movably provided in the pump element accommodating portion;
A hydraulic fluid is provided in the cam ring and discharges the hydraulic fluid sucked by the rotational drive of the drive shaft, and the specific discharge amount, which is a discharge amount per rotation, is changed in accordance with a change in the eccentric amount of the cam ring with respect to the drive shaft. A pump element;
A first fluid pressure chamber provided between the pump element housing portion and the cam ring and provided on a side where the volume decreases as the intrinsic discharge amount increases;
A second fluid pressure chamber provided between the pump element housing portion and the cam ring and provided on a side where the volume increases as the intrinsic discharge amount increases;
A suction port formed in the pump housing and opening into a suction area of the pump element;
A discharge port formed in the pump housing and open to a discharge region of the pump element;
A discharge passage connecting the discharge port and the power cylinder;
A metering orifice provided in the discharge passage;
A spool hole formed in the pump housing, a spool slidably provided in the spool hole, a valve high-pressure chamber provided on one side in the moving direction of the spool and introduced with pressure from the discharge port; A valve intermediate pressure chamber that is provided on the other side of the spool in the moving direction and into which the downstream pressure of the metering orifice is introduced, and that the spool slides in communication with the first fluid pressure chamber or the second fluid pressure chamber. And a valve hole whose flow area is variably controlled, and controls the pressure introduced into the first fluid pressure chamber or the second fluid pressure chamber as the flow area of the valve hole changes. A control valve for controlling the moving position of the cam ring;
A high-pressure introduction path connecting the discharge port and the valve high-pressure chamber;
An intermediate pressure introduction path connecting the valve intermediate pressure chamber and the downstream side of the metering orifice;
A branch passage connected to the low pressure region that is connected to the middle of the high pressure introduction path or the valve high pressure chamber and maintained at about atmospheric pressure,
On the high-pressure introduction path, a first throttle portion provided at a position closer to the discharge port than a connection point with the branch passage;
A second throttle portion provided in the branch passage,
Either the first throttle part or the second throttle part is a variable orifice that variably controls the flow path area according to the movement of the cam ring,
When the first throttle portion is a variable orifice, the variable orifice increases the flow path area as the cam ring moves in a direction in which the specific discharge amount decreases.
When the second throttle portion is a variable orifice, the variable orifice increases the flow path area as the cam ring moves in a direction in which the specific discharge amount increases.

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