JP2009036137A - Variable displacement vane pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To save energy and reduce noise and vibration simultaneously in a variable displacement vane pump by flow rate reduction and pulsation reduction during relief, by solving problems that pressure pulsation is generated during relief when a relief flow rate is reduced in particular, in the variable displacement vane pump, and that an increase quantity of a controlled flow rate becomes large when delivery pressure rises. <P>SOLUTION: This pump is provided with a first hydraulic pressure chamber 40 and a second hydraulic pressure chamber 41 at both sides of a cam ring 15 capable of oscillating in a front body 10, and includes a control valve 30 controlling the oscillation of the cam ring and a relief valve 32 opening when pressure is not lower than predetermined pressure. A variable damper orifice 20 reducing a channel cross section area during the operation of the relief valve is formed of a cam ring hole formed at the axial direction end surface of the cam ring, and communication holes 20b, 20c opposing the surface. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a variable displacement pump used in a working fluid utilizing device such as a power steering device that reduces the steering force of an automobile.

  As a pump for a power steering device, a pump directly rotated by an automobile engine is often used. Among these, a variable displacement vane pump that can reduce the discharge flow rate per revolution as the number of revolutions is proposed for high-speed running with a high engine revolution that does not require a large pump delivery rate. (For example, Patent Document 1). This variable displacement vane pump is excellent in terms of energy efficiency because the driving torque can be reduced.

  In a power steering pump, the pressure increases due to steering, and the pump enters a relief state when the load increases due to a stationary operation. In the variable displacement vane pump described above, pressure pulsation may occur during relief, which may be a problem. Regarding suppression of vibration of the relief valve, a technique having a damper function by attaching an elastic member to the relief valve or providing an orifice in a spring chamber is known (for example, Patent Document 2).

JP 2001-140772 A JP 2006-207833 A

  The variable displacement vane pump reduces the driving torque by reducing the flow rate in the relief state, and can save energy. In order to reduce the relief flow rate, the pilot orifice may be reduced. However, if the pilot orifice is reduced, there is a problem that the relief valve vibrates.

  In the pumps of the prior art, the relief valve is attached with an elastic member, so that the vibration of the relief valve can be suppressed. However, sufficient consideration has not been given to the suppression of pressure pulsation, and consideration is given to vibration and noise caused by pressure pulsation. Was not made enough.

  As a method for solving the problem of vibration and noise, a method of suppressing the flow pulsation by inserting a fixed throttle between the upstream side of the metering orifice and the high pressure side of the control valve can be considered. However, in this case, when the discharge pressure rises without relief, the control valve leaks and the pressure loss at the damper orifice causes a small pressure difference at both ends of the control valve and a small amount of control valve opening. Is difficult to swing, and there is a problem that the flow rate increases and the efficiency deteriorates as compared to when the pressure is low.

  An object of the present invention is to suppress pressure pulsation during operation of a relief valve without causing such a decrease in pump efficiency.

In order to meet such a problem, the variable displacement vane pump according to the present invention is:
A pump body;
A drive shaft pivotally supported by the pump body;
A rotor provided in the pump body and driven to rotate by a drive shaft;
A vane provided so that it can freely appear and disappear in a plurality of slots provided in the circumferential direction of the rotor;
A cam ring that is eccentrically provided in the pump body, is formed in an annular shape, and forms a plurality of pump chambers together with a rotor and vanes on the inner peripheral side;
A first plate member (rear body) and a second plate member (pressure plate) provided on both axial sides of the cam ring;
A suction port that is provided on at least one side of the first plate member or the second plate member and that opens to a region where the volumes of the plurality of pump chambers increase, and a discharge port that opens to a region where the volumes of the plurality of pump chambers decrease When,
A first fluid pressure chamber formed on one side of the outer peripheral side of the cam ring; a second fluid pressure chamber formed on the other side;
A metering orifice provided in the discharge passage connected to the discharge port;
A first fluid pressure chamber having a high pressure chamber into which upstream pressure of the metering orifice is introduced, an intermediate pressure chamber into which downstream pressure is introduced, and a low pressure chamber connected to a reservoir tank for storing hydraulic oil; Or pressure control means (control valve) for controlling the pressure introduced into the second fluid pressure chamber;
A pilot orifice provided in a pilot passage connecting the downstream side of the metering orifice and the intermediate pressure chamber of the front pressure control means;
A relief valve that is provided between the pilot throttle and the reservoir tank, opens when the pressure is higher than a predetermined pressure, and discharges the pressure in the intermediate pressure chamber to the reservoir tank side;
A variable damper orifice that is provided in a high-pressure passage that connects the upstream side of the metering orifice and the high-pressure chamber of the pressure control means, and that reduces the cross-sectional area of the flow path at least when the relief valve is opened.

  The variable damper orifice may be formed between the cam ring axial end surface and the first plate member or the second plate member.

  The variable damper orifice may be formed in a piston that moves in the axial direction in accordance with the eccentricity of the cam ring.

  The variable damper orifice may be configured to reduce the flow path cross-sectional area based on the discharge pressure downstream of the discharge port.

  Further, the variable damper orifice may be configured such that the flow path cross-sectional area is reduced based on the differential pressure across the pilot orifice.

  The variable damper orifice may have a configuration in which the flow path cross-sectional area is reduced based on the downstream pressure of the relief valve.

  The metering orifice may be variably controlled so that the cross-sectional area of the flow path becomes smaller as the amount of eccentricity of the cam ring is smaller.

  Further, this variable displacement vane pump may be used as a pressure source of a power steering device for an automobile.

  According to the variable displacement pump according to the present invention, it is possible to simultaneously realize vibration reduction and energy saving at the time of relief without increasing the flow rate at the time of pressure increase other than at the time of relief.

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

  A first embodiment of the variable displacement vane pump 1 according to the present invention will be described with reference to FIGS.

  FIG. 1 shows a front view of a variable displacement vane pump according to the present invention, with a partial cross section taken at a low speed. FIG. 2 shows a front view of the relief state. 3 is a cross-sectional view taken along the line AA in FIG. Further, a cross-sectional view taken along line BB in FIG. 3 corresponds to FIG. FIG. 4 shows the relationship between the cam swing angle and the sectional area of the damper orifice.

  The variable displacement vane pump 1 includes a concave front body 10 into which a pump component such as a rotor 11, a vane 14, a cam ring 15, an adapter 12, a pressure plate 27, and a control valve 30 is inserted, and a rear cover 19. It is configured together.

  A shaft 13 for transmitting a driving force from the outside is connected to the rotor 11, and the shaft 13 is supported on the front body 10 via a bearing 28. A plurality of slots 29 are provided in the rotor 11, and vanes 14 that can move freely in the radial directions in the slots 29 are inserted.

  An adapter 12 is fitted in the recess of the front body 10, and a cam ring 15 that is supported so as to be able to swing inside the adapter 12 around the support pin 16 is arranged eccentrically with respect to the rotor 11. A first fluid pressure chamber 40 is formed on the left side of the cam ring 15 and a second fluid pressure chamber 41 is formed on the right side by the cam ring 15 and the adapter 12 in FIG. The cam ring 15 is urged by the compression coil spring 17 in the direction in which the pump capacity of the vane chamber 18 is maximized.

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

  Further, as shown in FIG. 3, a pressure plate 27 is fitted between the rotor 11, the cam ring 15, the vane 14, the adapter 12 and the front body 10.

  The control valve 30 includes a valve hole 30a formed in the front body 10, and a spool 30b, a spring 30c, and the like that are slidably disposed in the valve hole 30a. A spring chamber 36 is provided on one end side of the control valve 30, and a spring 30 c is installed. The control valve 30 operates in accordance with the relationship between the force due to the pressure of the control valve high pressure chamber 37 on one end side, the force due to the pressure of the spring chamber 36 on the other end side, and the force due to the spring force of the spring 30c. When the force in the right direction in the figure due to the pressure difference between the control valve high pressure chamber 37 and the spring chamber 36 becomes larger than the force in the left direction due to the spring 30c, and the spool 30b moves to the right in FIG. The flow path with the passage 33 connected to the first fluid pressure chamber 40 becomes larger, and the flow path between the passage 33 and the tank side becomes narrower.

  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 is equal to or higher than the set pressure determined by the spring 32d, the ball 32b and the retainer 32c operate integrally to open the seat portion 32a.

  Next, the connection of the flow path between each chamber is demonstrated. The suction port 22 is connected to a tank (not shown). The discharge port 21 is introduced into the pressure chamber 26 on the front body 10 side through a passage (not shown) provided in the pressure plate 27. The pressure chamber 26 is connected to a discharge side pipe 38 connected to a device such as a power cylinder (not shown) via a metering orifice 23, and further connected to a spring chamber 36 from an upstream side 38 a of the discharge side pipe via a pilot orifice 24. The The pressure chamber 26 is connected to the control valve high pressure chamber 37 via the variable damper orifice 20.

  The variable damper orifice 20 has a structure in which the portion where the cam ring hole 20a recessed in the side surface of the cam ring 15 and the communication holes 20b and 20c provided in the pressure plate 27 overlap is an orifice. The cam ring hole portion 20a and the communication holes 20b and 20c are configured such that the overlapping portion decreases when the swing of the cam ring 15 increases. The working fluid is guided from the pressure chamber 26 to the outside of the pressure chamber 26 through the overlapping portion of the cam ring hole 20 a and the communication holes 20 b and 20 c, and communicates with the control valve high pressure chamber 37. At this time, the position of the cam ring 15 at the time of relief may be set to a positional relationship of holes such that the cross-sectional area becomes smaller than that at the time of low rotation as shown in FIG.

  An example of the change in the cross-sectional area of the variable damper orifice is shown in FIG. When the swing angle of the cam ring is small, the sectional area of the variable damper orifice 20 is large. On the other hand, when the swing angle of the cam ring 15 is large, the sectional area of the variable damper orifice 20 is small.

  Next, the operation of the variable displacement vane pump 1 will be described. When a rotational driving force is input from the shaft 13, the vane 14 rotates together with the rotor 11 while being pressed against the cam ring 15, and the volume of the vane chamber 18 increases or decreases. In the section in which the volume increases, the pressure in the vane chamber 18 decreases and the working fluid is sucked from the suction port 22. The suctioned working fluid is pressurized as the volume of the vane chamber 18 decreases in a section where neither the tank nor the pressure chamber 26 is connected. The pressurized working fluid is guided from the discharge port 21 to the pressure chamber 26 as the volume of the vane chamber 18 decreases.

  As the pump speed increases and the discharge flow rate increases, the pressure loss at the metering orifice 23 increases, and the rightward force due to the pressure difference across the control valve 30 overcomes the leftward force of the spring 30c in FIG. Move to the right. The working fluid downstream of the variable damper orifice 20 is guided to the first fluid pressure chamber 40 through the opened control valve 30, and the cam ring 15 is swung in a direction to reduce the eccentricity of the cam ring 15 to discharge the flow rate per one rotation. Decrease.

  When the discharge pressure increases and becomes higher than the load of the spring 32d, the force due to the discharge pressure becomes higher than the force of the spring 32d of the relief valve 32, and the relief valve 32 is opened. The working fluid discharged from the pressure chamber 26 is returned to the tank through the relief valve 32. At this time, the working fluid flows from the pressure chamber 26 to the tank through the metering orifice 23, the pilot orifice 24, and the relief valve 32. This flow causes a pressure loss at the pilot orifice 24, and a pressure difference is generated on both sides of the control valve 30. For this reason, the control valve 30 is opened, the working fluid is guided to the first fluid pressure chamber 40, and the cam ring is swung in a direction to reduce the eccentricity of the cam ring 15, thereby reducing the discharge flow rate per one rotation.

  At this time, the cross-sectional area of the variable damper orifice 20 configured as a portion where the cam ring hole 20a and the communication holes 20b and 20c overlap with each other decreases. The smaller the sectional area of the variable damper orifice, the higher the damper effect and the operation of the control valve 30 is stabilized. Further, since the operation of the control valve 30 is stabilized, the swing of the cam ring 15 and the discharge flow rate are stabilized, and the vibration of the relief valve 32 can be suppressed.

  Except for the relief time, the cam ring 15 is mostly used within a relatively small swing angle, and the variable damper orifice 20 has a large sectional area. For this reason, the increase in the pressure difference before and after the variable damper orifice 20 due to the increased discharge pressure is small. That is, the rightward force due to the pressure difference between both ends of the control valve 30 is not reduced, and the control valve 30 is unlikely to open even when the discharge pressure increases. Therefore, since the cam ring 15 operates in the same manner as when the pressure is low, an increase in shaft driving torque can be suppressed to a small extent even when the discharge pressure increases.

  In this embodiment, the variable damper orifice 20 is not throttled when the cam ring 15 swings little, so that an increase in the control flow rate at high pressure can be suppressed. At the time of relief, the variable damper orifice 20 is throttled to suppress pressure pulsation during relief, so that the relief flow rate can be reduced and energy saving is achieved.

  Next, a second embodiment of the variable displacement vane pump 1 according to the present invention will be described with reference to FIGS.

  FIG. 5 is a cross-sectional view of the present invention as seen from the bottom surface in a state of low rotation, and FIG. A configuration other than that formed by a spool 20d that moves the variable damper orifice 20 in the axial direction in accordance with the eccentricity of the cam ring 15, a spring 20e that biases the spool 20d toward the cam ring 15 and a spring chamber 20f that is connected to the tank is implemented. Similar to Example 1.

  The spool 20d is connected to a conduit 34 connecting the pressure chamber 26 and the control valve high-pressure chamber 37, and the variable damper orifice 20 is configured so that the flow passage area of the conduit 34 is narrowed by the movement of the spool 20d. .

  When the relief valve 32 is not actuated, the cam ring 15 is used in a relatively small range, and the amount of movement of the spool 20d pressed against the cam ring 15 to the right side in the figure is small. At this time, the throttle of the variable damper orifice 20 is in a large state.

  When the discharge pressure increases and the relief valve 32 is activated, the control valve 30 is opened, the working fluid is guided to the first fluid pressure chamber 40, and the cam ring 15 moves to the right side in the drawing. Then, the spool 20d moves to the right as the cam ring 15 swings as shown in FIG. At this time, the positional relationship between the spool 20d and the pipe line 34 is preferably set such that the cross-sectional area is smaller at the position of the cam ring 15 at the time of relief than at the time of low rotation. As a result, the variable damper orifice 20 is throttled. Other operations are the same as those in the first embodiment.

  In this embodiment, in addition to the effects of the first embodiment, since the end face of the cam ring 15 is not required to be processed according to such a structure, leakage from the vane chamber 18 to the first fluid pressure chamber 40 at the time of high pressure is reduced. can do.

  Next, a third embodiment of the variable displacement vane pump 1 according to the present invention will be described with reference to FIG. In this embodiment, the variable damper orifice 20 is constituted by a spool 20g, a pressure chamber 20h on one end side thereof, a spring chamber 20i on the other end side, and a spring 20j in the spring chamber 20i, and a spring constituted at one end of the spool 20g. The chamber 20i is connected to the tank by a passage (not shown), and the discharge pressure is guided to the pressure chamber 20h at the other end. In addition, the variable damper orifice 20 is formed such that the flow path is throttled by operating the spool 20g in the pipe line 35 connecting the pressure chamber 26 and the control valve high pressure chamber 37. The force of the spring 20j is configured such that the operation start pressure of the spool 20g and the operation start pressure of the relief valve 32 are approximately the same. The configuration other than the variable damper orifice 20 is the same as that of the first embodiment.

  When the discharge pressure is low and the relief valve 32 does not operate, the force due to the pressure in the pressure chamber 20h of the variable damper orifice 20 is weaker than the force of the spring 20j in the spring chamber 20i at the other end, and the spool 20g does not move. At this time, the sectional area of the variable damper orifice 20 is constant in a large state.

  When the discharge pressure is high and the relief valve 32 operates, the force due to the pressure in the pressure chamber 20h of the variable damper orifice 20 exceeds the force of the spring 20j in the spring chamber 20i at the other end, and the spool moves to the right side in the figure. Then, the cross-sectional area of the variable damper orifice 20 is reduced by the side surface of the spool 20g. Other operations are the same as those in the first embodiment.

  With such a configuration, the discharge pressure at which the variable damper orifice 20 starts to be throttled can be arbitrarily set.

  A mechanism that reduces the cross-sectional area of the variable damper orifice 20 based on the discharge-side pressure can be realized regardless of whether the relief state is set by the same mechanism.

  Next, a variable displacement vane pump 1 according to a fourth embodiment of the present invention will be described with reference to FIG. In the present embodiment, the upstream pressure of the pilot orifice 24 is guided to the pressure chamber 20h formed at one end of the spool 20g, and the downstream pressure of the pilot orifice 24 is guided to the spring chamber 20i formed at the other end. The configuration other than that is the same as that of the third embodiment.

  When the discharge pressure is low and the relief valve 32 does not operate, no pressure loss occurs in the pilot orifice 24, and the pressure is the same upstream and downstream of the pilot orifice 24. For this reason, the pressures in the pressure chamber 20h and the spring chamber 20i of the variable damper orifice 20 are the same, and the spool 20g does not move. At this time, the sectional area of the variable damper orifice 20 is constant in a large state.

  When the discharge pressure is high and the relief valve 32 is operated, a pressure loss chamber is generated in the pilot orifice 24, and the pressure downstream of the pilot orifice 24 is lower than the upstream. For this reason, the pressure chamber 20h of the variable damper orifice 20 has a higher pressure than the spring chamber 20i. When this pressure difference becomes larger than the force of the spring 20j, the spool 20g moves to the left in the figure. Then, the cross-sectional area of the variable damper orifice 20 is reduced by the side surface of the spool 20g. Other operations are the same as those in the third embodiment.

  With this configuration, the variable damper orifice 20 can be reduced only when the relief valve 32 is opened.

  Next, a fifth embodiment of the variable displacement vane pump 1 according to the present invention will be described with reference to FIG. In this embodiment, a spring chamber 20i formed at one end of the spool 20g is connected to a tank by a passage (not shown), and the pressure chamber 20h at the other end is led to a relief downstream chamber 43 downstream of the relief valve 32, The configuration and operation of the relief downstream chamber 43 are the same as in the third embodiment except that the relief downstream chamber 43 is connected to the tank via an orifice.

  When the discharge pressure is low and the relief valve 32 does not operate, the relief downstream chamber 43 is the same as the tank pressure. For this reason, the pressures of the pressure chamber 20h and the spring chamber 20i of the variable damper orifice 20 are also equal, and the spool 20g does not move. At this time, the sectional area of the variable damper orifice 20 is constant in a large state.

  When the discharge pressure is high and the relief valve 32 operates, a high-pressure working fluid flows through the pilot orifice 24 and the pressure in the relief downstream chamber 43 increases. For this reason, the pressure chamber 20h of the variable damper orifice 20 has a higher pressure than the spring chamber 20i. When this pressure difference becomes larger than the force of the spring 20j, the spool 20g moves to the left in the figure. Then, the cross-sectional area of the variable damper orifice 20 is reduced by the side surface of the spool 20g. Other operations are the same as those in the third embodiment.

  With this configuration, since the pressure for operating the variable damper orifice 20 is low, leakage for operating the spool 20g can be reduced.

  Next, a sixth embodiment of the variable displacement vane pump 1 according to the present invention will be described with reference to FIGS. In this embodiment, the variable damper orifice 20 is constituted by an inner peripheral end 15 a of the cam ring 15 and a fluid passage 44 formed in the pressure plate 27. When the cam swing angle increases, the fluid passage 44 is narrowed by the inner peripheral end 15a of the cam ring 15, and at this time, at least the position of the cam ring 15 at the time of relief has a hole with a smaller cross-sectional area than at the time of low rotation. It is set as a positional relationship. The configuration other than the variable damper orifice 20 is the same as that of the first embodiment.

  When the relief valve 30 does not operate, the cam ring 15 swings slightly, and at this time, the throttle of the variable damper orifice 20 is large.

  When the discharge pressure increases and the relief valve 32 is activated, the control valve 30 is opened, the working fluid is guided to the first fluid pressure chamber 40, and the cam ring 15 moves to the right side in the drawing. As a result, the variable damper orifice 20 is throttled. Other operations are the same as those in the first embodiment.

  With such a configuration, the cam ring 15 does not require the cam ring hole 20a, and the cam ring 15 can be easily processed.

  A mechanism that makes the variable damper orifice 20 smaller as the eccentric amount of the cam ring 15 is smaller can be realized regardless of whether the relief state is set in the same configuration.

  Next, a seventh embodiment of the variable displacement vane pump 1 according to the present invention will be described with reference to FIG. In this embodiment, in addition to the variable damper orifice 20 shown in any one of the first to sixth embodiments, a variable metering orifice 45 is provided that reduces the cross-sectional area of the channel as the swing angle of the cam ring 15 increases. The variable metering orifice 45 has a structure in which the cam ring hole 45a recessed in the side surface of the cam ring 15 and the communication holes 45b and 45c provided in the pressure plate 27 overlap with each other. The cam ring hole 45a and the communication holes 45b and 45c have a shape in which the overlapping portion is reduced when the swing of the cam ring 15 is increased, and the sectional area of the orifice is reduced with the swing of the cam ring. The working fluid is guided from the pressure chamber 26 to the outside of the pressure chamber 26 through the overlapping portion of the cam ring hole 45a and the communication holes 45b and 45c, and communicates with the discharge-side pipe upstream portion 38a. The configuration other than the variable metering orifice 45 is the same as that of the first embodiment.

  When the relief valve 32 is not in operation, the swing angle of the cam ring 15 is slight, and the cross-sectional area of the variable metering orifice 45 cannot be reduced.

  When the relief valve 32 is operated, the sectional area of the variable metering orifice 45 is reduced in the same manner as the sectional area of the variable damper orifice 20 is reduced due to the swing of the cam ring 15. Other operations are the same as those in the first to sixth embodiments.

  With such a configuration, the flow rate during relief can be further reduced, leading to further energy saving.

  Moreover, it is good also as a power steering apparatus which inputs the motive power of an engine as a drive force of the shaft 13 to the input side of the variable capacity type vane pump 1 of Examples 1-7, and connects a power cylinder etc. to the discharge side piping 38. In this case, vibration and noise can be reduced and energy can be saved when the power steering apparatus is stationary, and energy can be saved during steering.

  Naturally, the use of the variable displacement vane pump 1 is not limited to the power steering device, and may be used as a pump for other fluid machines.

It is a front view which shows the time of the maximum eccentricity of Example 1 of the variable displacement vane pump according to the present invention. FIG. 4 is a cross-sectional view taken along line BB in FIG. 3. It is a front view which shows the time of relief of Example 1 of the variable displacement vane pump which concerns on this invention. It is sectional drawing in the AA of FIG. FIG. 4 is a characteristic diagram for explaining a relationship between a swing angle of a cam ring and a sectional area of a variable damper orifice in the variable displacement vane pump of FIGS. 1 to 3. It is sectional drawing seen from the bottom face which shows the time of the maximum eccentricity of Example 2 of the variable displacement vane pump according to the present invention. It is sectional drawing seen from the bottom face which shows the time of relief of Example 2 of the variable displacement vane pump concerning the present invention. It is a front view which shows the time of the maximum eccentricity of Example 3 of the variable displacement vane pump according to the present invention. It is a front view which shows the time of the maximum eccentricity of Example 4 of the variable displacement vane pump according to the present invention. It is a front view which shows the time of the maximum eccentricity of Example 5 of the variable displacement vane pump according to the present invention. It is a front view which shows the time of the maximum eccentricity of Example 6 of the variable displacement vane pump according to the present invention. It is sectional drawing in the CC line of FIG. It is a front view which shows the time of the maximum eccentricity of Example 7 of the variable displacement vane pump according to the present invention.

Explanation of symbols

1 Variable displacement vane pump
DESCRIPTION OF SYMBOLS 10 Front body 11 Rotor 12 Adapter 13 Shaft 14 Vane 15 Cam ring 15a Inner peripheral end 16 Support pin 17 Compression coil spring 18 Vane chamber 19 Rear cover 20 Variable damper orifice 20a, 45a Cam ring hole 20b, 20c, 45b, 45c Communication hole 20d, 20g, 30b Spool 20e, 20j, 30c, 32d Spring 20f, 20i, 36 Spring chamber 20h, 26 Pressure chamber 21 Discharge port 22 Suction port 23 Metering orifice 24 Pilot orifice 25, 28 Bearing 27 Pressure plate 29 Slot 30 Control valve 30a Valve hole 32 Relief valve 32a Seat part 32b Ball 32c Retainer 33 Passage 34, 35 Pipe line 37 Control valve high pressure chamber 38 Discharge side pipe 38a Discharge Piping upstream portion 40 first fluid pressure chamber 41 and the second fluid pressure chamber 43 relief downstream chamber 44 fluid passageway 45 variable metering orifice T tank

Claims (20)

A pump body;
A drive shaft pivotally supported by the pump body;
A rotor provided in the pump body and driven to rotate by the drive shaft;
A vane provided so as to freely appear and disappear in a plurality of slots provided in a circumferential direction of the rotor;
A cam ring that is eccentrically provided in the pump body, is formed in an annular shape, and forms a plurality of pump chambers together with the rotor and vanes on the inner peripheral side;
A first plate member and a second plate member provided on both axial sides of the cam ring;
Provided on at least one side of the first plate member or the second plate member, and opens to a region where the volumes of the plurality of pump chambers increase, and opens to a region where the volumes of the plurality of pump chambers decrease. A discharge port;
A first fluid pressure chamber formed on one side of the outer peripheral side of the cam ring; a second fluid pressure chamber formed on the other side;
A metering orifice provided in a discharge passage connected to the discharge port;
The first fluid has a high pressure chamber into which upstream pressure of the metering orifice is introduced, an intermediate pressure chamber into which downstream pressure is introduced, and a low pressure chamber connected to a reservoir tank for storing hydraulic oil. Pressure control means for controlling the pressure introduced into the pressure chamber or the second fluid pressure chamber;
A pilot orifice provided in a pilot passage connecting the downstream side of the metering orifice and the intermediate pressure chamber of the pressure control means;
A relief valve that is provided between the pilot throttle and the reservoir tank, opens when the pressure is equal to or higher than a predetermined pressure, and discharges the pressure in the intermediate pressure chamber to the reservoir tank side;
A variable damper orifice provided in a high-pressure passage connecting the upstream side of the metering orifice and the high-pressure chamber of the pressure control means, and at least when the relief valve opens, a variable damper orifice,
A variable displacement vane pump characterized by comprising:   2. The variable displacement vane pump according to claim 1, wherein the variable damper orifice is formed between the cam ring axial end surface and the first plate member or the second plate member. .   2. The variable displacement vane pump according to claim 1, wherein the variable damper orifice is formed in a piston that moves in an axial direction with the eccentricity of the cam ring.   2. The variable displacement vane pump according to claim 1, wherein the variable damper orifice has a flow passage sectional area that is reduced based on a discharge pressure downstream of the discharge port.   2. The variable displacement vane pump according to claim 1, wherein the variable damper orifice reduces a cross-sectional area of the flow path based on a differential pressure across the pilot orifice.   2. The variable displacement vane pump according to claim 1, wherein the variable damper orifice has a flow passage cross-sectional area that is reduced based on a downstream pressure of the relief valve. 3.   2. The variable displacement vane pump according to claim 1, wherein the metering orifice is variably controlled so that the cross-sectional area of the flow path becomes smaller as the eccentric amount of the cam ring is smaller. A pump body;
A drive shaft pivotally supported by the pump body;
A rotor provided in the pump body and driven to rotate by the drive shaft;
A vane provided so as to freely appear and disappear in a plurality of slots provided in a circumferential direction of the rotor;
A cam ring that is eccentrically provided in the pump body, is formed in an annular shape, and forms a plurality of pump chambers together with the rotor and vanes on the inner peripheral side;
A first plate member and a second plate member provided on both axial sides of the cam ring;
Provided on at least one side of the first plate member or the second plate member, and opens to a region where the volumes of the plurality of pump chambers increase, and opens to a region where the volumes of the plurality of pump chambers decrease. A discharge port;
A first fluid pressure chamber formed on one side of the outer peripheral side of the cam ring; a second fluid pressure chamber formed on the other side;
A metering orifice provided in a discharge passage connected to the discharge port;
The first fluid has a high pressure chamber into which upstream pressure of the metering orifice is introduced, an intermediate pressure chamber into which downstream pressure is introduced, and a low pressure chamber connected to a reservoir tank for storing hydraulic oil. Pressure control means for controlling the pressure introduced into the pressure chamber or the second fluid pressure chamber;
A pilot orifice provided in a pilot passage connecting the downstream side of the metering orifice and the intermediate pressure chamber of the pressure control means;
A relief valve that is provided between the pilot throttle and the reservoir tank, opens when the pressure is equal to or higher than a predetermined pressure, and discharges the pressure in the intermediate pressure chamber to the reservoir tank side;
A variable damper orifice that is provided in a high-pressure passage that connects the upstream side of the metering orifice and the high-pressure chamber of the pressure control means, and reduces the cross-sectional area of the flow path as the eccentric amount of the cam ring decreases;
A variable displacement vane pump characterized by comprising:   9. The variable displacement vane pump according to claim 8, wherein the variable damper orifice is formed between the cam ring axial end surface and the first plate member or the second plate member. .   10. The variable displacement vane pump according to claim 9, wherein the variable damper orifice is formed in the first plate member or the second plate member so as to face a groove formed in an axial end surface of the cam ring. And a variable displacement vane pump characterized by comprising an open end face of the oil passage.   10. The variable displacement vane pump according to claim 9, wherein the variable damper orifice is formed in the first plate member or the second plate member so as to face the inner peripheral end of the axial end surface of the cam ring and the inner peripheral end. And a variable displacement vane pump characterized by comprising an open end face of the oil passage.   9. The variable displacement vane pump according to claim 8, wherein the variable damper orifice is formed in a piston that moves in an axial direction with the eccentricity of the cam ring.   9. The variable displacement vane pump according to claim 8, wherein the metering orifice is variably controlled so that the cross-sectional area of the flow path becomes smaller as the eccentric amount of the cam ring is smaller. A pump body;
A drive shaft pivotally supported by the pump body;
A rotor provided in the pump body and driven to rotate by the drive shaft;
A vane provided so as to freely appear and disappear in a plurality of slots provided in a circumferential direction of the rotor;
A cam ring that is eccentrically provided in the pump body, is formed in an annular shape, and forms a plurality of pump chambers together with the rotor and vanes on the inner peripheral side;
A first plate member and a second plate member provided on both axial sides of the cam ring;
Provided on at least one side of the first plate member or the second plate member, and opens to a region where the volumes of the plurality of pump chambers increase, and opens to a region where the volumes of the plurality of pump chambers decrease. A discharge port;
A first fluid pressure chamber formed on one side of the outer peripheral side of the cam ring; a second fluid pressure chamber formed on the other side;
A metering orifice provided in a discharge passage connected to the discharge port;
The first fluid has a high pressure chamber into which upstream pressure of the metering orifice is introduced, an intermediate pressure chamber into which downstream pressure is introduced, and a low pressure chamber connected to a reservoir tank for storing hydraulic oil. Pressure control means for controlling the pressure introduced into the pressure chamber or the second fluid pressure chamber;
A pilot orifice provided in a pilot passage connecting the downstream side of the metering orifice and the intermediate pressure chamber of the pressure control means;
A relief valve that is provided between the pilot throttle and the reservoir tank, opens when the pressure is equal to or higher than a predetermined pressure, and discharges the pressure in the intermediate pressure chamber to the reservoir tank side;
A variable damper orifice that is provided in a high-pressure passage that connects the upstream side of the metering orifice and the high-pressure chamber of the pressure control means, and that reduces the cross-sectional area of the flow path when the discharge pressure on the downstream side of the discharge port is greater than or equal to a predetermined pressure;
A variable displacement vane pump characterized by comprising:   15. The variable displacement vane pump according to claim 14, wherein the variable damper orifice is formed between the cam ring axial end surface and the first plate member or the second plate member. .   15. The variable displacement vane pump according to claim 14, wherein the variable damper orifice is formed in a piston that moves in an axial direction with the eccentricity of the cam ring.   15. The variable displacement vane pump according to claim 14, wherein the variable damper orifice has a flow passage cross-sectional area that is reduced based on a discharge pressure downstream of the discharge port.   15. The variable displacement vane pump according to claim 14, wherein the variable damper orifice has a flow passage cross-sectional area reduced based on a differential pressure across the pilot orifice.   15. The variable displacement vane pump according to claim 14, wherein the variable damper orifice has a flow passage sectional area that is reduced based on a downstream pressure of the relief valve.   15. The variable displacement vane pump according to claim 14, wherein the metering orifice is variably controlled so that the cross-sectional area of the flow path decreases as the eccentric amount of the cam ring decreases.

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