JPH0532784U - Variable displacement vane pump device - Google Patents

Abstract

(57) [Summary] [Purpose] The discharge valve discharged from a specific pump chamber by the switching valve 1 is guided to the suction side to reduce the flow resistance and reduce the size of the suction side communication type pump, which saves energy. Aim for weight reduction. [Configuration] Specific discharge port 3 on the side connected to the switching valve 1
1'is provided with a communication passage 23 communicating with the switching valve 1 and a discharge passage 33 communicating with the pressure chamber 27. Discharge port 8 of this discharge path 33
A check valve including a valve 9 and a spring 99 is provided at position 1. The discharge oil from the specific discharge port 31 ′ flows into the pressure chamber 27 through the discharge passage 33 and the check valve only when the communication passage 23 and the suction side passage 22 are shut off by the operation of the switching valve 1. [Effect] The flow path of the circulating hydraulic oil and the discharge oil from the specific discharge port 31 ′ is shortened, and the energy loss based on these flow resistances is reduced.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a variable displacement vane pump, and more particularly to an energy-saving hydraulic pump device suitable for supplying working fluid to a vehicle power steering device.

[0002]

[Prior Art]

 In the hydraulic pump device used in the power steering system for automobiles, the discharge flow rate of the pump is set so that the steering force can be sufficiently assisted even when the vehicle is running at low speed (generally when the engine speed is low). Therefore, in such a hydraulic pump device, the hydraulic oil is discharged at a flow rate proportional to the engine speed as the engine speed (engine speed) rises. This means that the flow rate of hydraulic oil becomes excessive during high-speed driving (generally when the engine speed is high), where essentially no steering force assistance is required. In order to deal with such a phenomenon, a part of the hydraulic oil discharged from the pump (discharging oil) is not sent to the power assist section of the power steering device, but is bypassed to the hydraulic pump to control the flow rate. The valve (flow control valve) method has been widely adopted in the past.

However, in this flow control valve system, high-pressure discharge oil discharged from the hydraulic pump is guided to the flow control valve, discharged from there to a bypass passage, and then returned to the suction port side. Therefore, when the engine rotates at high speed, energy is consumed according to the engine speed. In other words, in the bypass recirculation method using the flow control valve, energy loss (loss) due to bypass recirculation occurs when the vehicle is traveling and steering assistance is not required when traveling at high speeds. There is a problem that it leads to deterioration of vehicle fuel consumption. Therefore, as a means for reducing the energy loss when such steering force assistance is not required, for example, a method using a switching valve as described in JP-A-60-256579 is conventionally adopted. Has been done.

This is a vane pump including a rotor, a vane, a cam ring, a side plate, a housing, and the like, to which a switching valve including a spool and a spring is added. By providing such a switching valve, if the power assist unit needs only a small amount of hydraulic oil for assisting the steering force, the hydraulic oil will be circulated through a part of the vane pump, and the pump function of that part will be circulated. When the large amount of hydraulic oil is required, the function of the pump chamber that had been stopped is restored to try to perform sufficient power assist. It is a thing. However, since the conventional hydraulic oil is a relatively high-pressure discharge oil existing in the pressure chambers, the energy consumed by the hydraulic oil circulation action is large. Therefore, in order to eliminate such drawbacks, the hydraulic oil to be circulated is not guided from the pressure chamber where the high-pressure discharge oil exists, but the oil just discharged from the discharge port is not discharged to the pressure chamber and is directly discharged. A vane pump device that employs a so-called suction side communication method of returning to the suction port side has already been devised.

As shown in FIG. 3, this is a vane pump including a rotor 6, a vane 7, a cam ring 5, side plates 3 and 4, a housing 2, and a switching valve 1 including a spool 11 and a spring 15 and the like. It has a different structure. Further, the switching valve 1 has a switching valve housing 12 having a cylinder chamber connected to various passages, and a sub-cylinder 13 is provided in the switching valve housing 12 so as to surround the spool 11. Accordingly, the switching valve 1 has a double structure.

[0006]

[Problems to be solved by the device]

 By the way, in the suction side communication type variable displacement vane pump device having the above switching valve, when the pump is switched from a low output state (low load pressure) to a high output state (high load pressure), a high load pressure is applied. There is a phenomenon in which the hydraulic oil (discharging oil) flows back from the pressure chamber to the pump chamber via a specific low-pressure discharge port and back to the reserve tank.

In order to solve such a problem, as shown in FIG. 3, the discharge oil from the specific discharge port 45 flows into the pressure chamber 27 through the communication passage 23 and the connection passage 234. A check valve 32 is provided at the outlet. However, when the above specific pump chamber is switched so as to recover the pump function and also discharge the discharge oil from the second discharge port 45, the discharge oil is discharged from the communication passage 23 as shown by the solid line arrow. Flow through the cylinder chamber 122 and the connecting passage 234 to the check valve 32. Then, the check valve 32 is opened here, and the check valve 32 flows to the pressure chamber 27 through the cylinder chamber 122, the hydraulic oil flow port 132, the switching valve pressure chamber 14, the discharge side passage 24, and the like. At this time, the discharged oil is subjected to flow resistance at these points by passing through the long passages 23 and 234, the narrow circulation port 132, and the check valve 32. Since the pump device is driven under such a condition, the energy consumption in the pump device is increased, and the energy saving effect may be halved. Therefore, it is an object (problem) of the present invention to solve the problem of energy loss due to such flow resistance and to provide a vane pump device having a switching valve that can obtain a more energy-saving effect.

[0008]

[Means for Solving the Problems]

 In order to solve the above problems, in the present invention, a rotor that is housed in a housing and is rotationally driven, a vane that slides in a slit of the rotor, the rotor that is outside the vane, A cam ring that forms a pump chamber with a vane, etc., a side plate on both sides of the rotor, vane, and cam ring that contributes to the formation of the pump chamber, a plurality of discharge ports provided on the side plate, the cam ring and the side plate If the discharge flow rate of discharge oil (working oil) delivered from a vane pump consisting of multiple suction ports, etc., provided near the circumferential end of the A hydraulic pump device comprising a flow control valve for bypassing the surplus discharged oil to a bypass passage connected to the suction port, A switching valve that has a suction-side passage that communicates with the port and a communication passage that communicates with a specific port of the discharge port, and that switches between a communication state and a blocking state between the communication passage and the suction passage. In the variable displacement vane pump device configured as described above, in addition to the communication passage, the communication between the communication passage and the suction side passage is blocked at a specific discharge port of the plurality of discharge ports provided on the side plate. A discharge passage through which the discharge fluid flows is provided only when the state is in a state, and a plurality of discharge openings with a large opening area are provided near the center of the rotation axis of the discharge passage and a valve mechanism for opening and closing the discharge opening. It was decided to adopt a configuration having a check valve

[0009]

[Action]

 With the above configuration, in the present invention, when the vane pump starts operating, the hydraulic oil sucked from the suction passage in FIG. 1 is guided to the suction chamber 28 via the bypass passage 29. A part of the hydraulic oil guided to the suction chamber 28 is sucked from the first suction port 41, boosted in the pump chamber and discharged from the first discharge port 31 to the pressure chamber 27, and then the flow control valve 26. Is sent to a power assist unit (not shown) of the power steering device by being controlled by the flow rate.

By the way, when the power assist section is not assisting the steering force (power assist), the hydraulic pressure (load pressure) of the power assist section is low, and therefore the pressure of the pressure chamber 27 is reduced. Is also kept low. Therefore, the spool 11 is pushed to the right by the action of the spring force of the spring 15 and placed in the state shown by the solid line in FIG. As a result, the suction side passage 22 and the communication passage 23 are brought into communication with each other via the sub-cylinder chamber 133 and the like, and the discharge oil discharged from the second discharge port 31 ′ which is a specific discharge port is directly connected to the communication passage 23 and the sub-cylinder. It is sucked into the second suction port 41 ′ via the chamber 133, the suction side passage 22, and the suction chamber 28. That is, in the pump chamber formed by the second suction port 41 'and the second discharge port 31', the suction working oil simply circulates.

On the other hand, when the load pressure rises and the pressure in the pressure chamber 27 becomes high, the pressure in the switching valve pressure chamber 14 also rises, so the spool 11 resists the spring force of the spring 15 and moves to the left. It moves to the direction shown in FIG. As a result, the communication passage 23 and the suction-side passage 22 are blocked by the land 111 of the spool 11, so that the working oil (discharge oil) discharged from the second discharge port 31 'is indicated by the solid arrow. As described above, the fluid flows toward the discharge passage 33 side that communicates the second discharge port 31 ′ with the pressure chamber 27, and further flows out from the discharge port 81 to the pressure chamber 27 by opening the valve 9. Therefore, the oil discharged from the second discharge port 31 ′ is sent to the pressure chamber 27 through a short flow path with a small flow resistance, and is sent to the power assist unit from here to contribute to assisting the steering force.

[0012]

【Example】

 An embodiment according to the present invention will be described with reference to the drawings. As shown in FIG. 1, the configuration of the present embodiment is a variable displacement vane pump device including a vane pump including a rotor 6, a vane 7, a cam ring 5 and the like, and a switching valve 1 including a spool 11, a spring 15 and the like. It is based on what is. In such a basic configuration, the vane pump is conventionally known, and includes a rotor 6 housed in the housing 2 and rotationally driven, a vane 7 that slides in a slit of the rotor 6, A cam ring 5, which is outside the vane 7 and forms a pump chamber with the rotor 6, the vane 7 and the like, Side plates 3 and 4, which are on side faces of the rotor 6, the vane 7, and the cam ring 5, and contribute to the formation of the pump chamber, A hydraulic pump device including a plurality of discharge ports 31 and 31 'provided on the side plates 3 and 4 and a plurality of suction ports 41 and 41' provided near the circumferential ends of the side plates 3 and 4 and the cam ring 5. In addition to these, the flow control valve 26 has a pressure chamber 27 connected to the discharge port 31 and the like, and is connected to the pressure chamber 27. Further, it has a bypass passage 29 for bypassing the excess hydraulic oil from the flow control valve 26 to the suction side, and downstream of the bypass passage 29, the suction ports 41, 41 '. Has a ring-shaped suction chamber 28 connected to the.

In addition to these configurations, in the side plate 3 on the side having the discharge ports 31, 31 ′, as shown in FIG. 1, a discharge passage 33 is provided continuously with the second discharge port 31 ′. ing. Further, the discharge passage 33 is provided so as to extend in the direction of the center line of the rotation shaft as shown in FIG. 2, and its final end is provided so as to open in a circle around the center line. Further, a disc-shaped sub-plate 8 is provided in contact with the side plate 3, and the sub-plate 8 has a large opening continuous with the opening of the discharge passage 33 as shown in FIG. A discharge port 81 having an area is provided. A guide 82 is provided near the center of the sub-plate 8, and the guide 82 is provided with a disc-shaped valve 9 for opening and closing the discharge port 81 provided in the sub-plate 8. There is. The valve 9 is provided with a spring 99 that constantly acts to close the discharge port 81, and the spring 99 and the valve 9 form a check valve.

The switching valve 1 has a sub-cylinder 13 in a switching valve housing 12, and a sub-cylinder chamber 133 formed in the sub-cylinder 13 has a spool 11 and a spring 15 built therein. In addition to these, a cylinder chamber 122 is provided between the switching valve housing 12 and the sub-cylinder 13, and pressure is applied to the pressure chamber 27 on one head side of the spool 11. A switching valve pressure chamber 14 communicating with the introduction passage 21 and a hydraulic oil flow port 132 is provided, and a spring 15 that gives a spring reaction force to the spool 11 is provided on the other head side. Has become. Of the lands provided in the vicinity of the head of the spool 11, the land 111 provided on the side facing the switching valve pressure chamber 14 has the thickness of the land of the opening of the hydraulic oil flow port 132. Is configured to have sufficient value to close the That is, the land 111 is configured to overlap the hydraulic oil flow port 132.

Further, various passages are provided between the vane pump and the switching valve 1. That is, as shown in FIG. 1, the side plate 3 of the vane pump is provided with a second discharge port 31 ′, and the working oil (discharge oil) discharged from the second discharge port 31 ′ is guided to the switching valve 1. The communication passage 23 is provided for this purpose. That is, the discharge passage 33 and the communication passage 23 are connected to the second discharge port 31 '. The other end of the communication passage 23 is connected to the cylinder chamber 122 of the switching valve 1, and is further connected to the sub-cylinder chamber 133 via the hydraulic oil flow port 132 provided in the sub-cylinder 13. It has become. Next, the pressure introducing passage 21 is provided so as to be connected to the pressure chamber 27, and the other end of the pressure introducing passage 21 is connected to the cylinder chamber 122 of the switching valve 1 and further the operation provided in the sub-cylinder 13. It communicates with the switching valve pressure chamber 14 through the oil flow port 132. Further, as shown in FIG. 1, a ring-shaped suction chamber 28 is provided on the outer peripheral portions of the side plates 3 and 4 and the cam ring 5, and a suction side passage 22 is provided so as to be continuous with the suction chamber 28. .. The other end of the suction-side passage 22 is connected to the cylinder chamber 122, and is further connected to the sub-cylinder chamber 133 via the hydraulic oil flow port 132 provided in the sub-cylinder 13. ..

The operation state of the present embodiment having the above configuration will be described. When the vane pump starts operating, for example, in FIG. 1, the hydraulic oil sucked from the suction passage is guided to the suction chamber 28 via the bypass passage 29. Part of the hydraulic oil introduced to the suction chamber 28 is sucked from the first suction port 41, pressurized in the pump chamber and discharged from the first discharge port 31 to the pressure chamber 27, and then the flow control valve 26. Flow control is received by and is sent to the power assist unit (not shown) of the power steering apparatus.

By the way, when the power assist unit is not performing steering force assistance (power assist), the hydraulic pressure (load pressure) of the power assist unit is low, and therefore the load of the power assist unit is low. The pressure in the pressure chamber 27 to which the pressure is propagated is also kept low. As a result, the pressure introduced from the pressure chamber 27 into the switching valve pressure chamber 14 through the pressure introduction passage 21 and further through the hydraulic oil flow port 132 is low, and the spool 11 moves to the right due to the action of the spring force of the spring 15. It is pushed and placed in the state shown by the solid line in FIG. Therefore, the suction-side passage 22 and the communication passage 23 are in communication with each other through the sub-cylinder chamber 133 and the like, and the discharge oil discharged from the second discharge port 31 ′ which is a specific discharge port is indicated by the broken line arrow in FIG. As described above, the fluid is sucked into the second suction port 41 ′ via the communication passage 23, the hydraulic oil flow port 132, the sub cylinder chamber 133, the suction side passage 22, and the suction chamber 28. That is, in the pump chamber formed by the second suction port 41 'and the second discharge port 31', the working oil simply circulates. In this case, in particular, the circulating fluid directly flows back to the suction port 41 'without passing through a check valve, a check valve, etc., so that energy loss due to flow resistance or the like can be reduced.

On the other hand, when the power assist unit starts steering force assistance, the load pressure rises and the pressure in the pressure chamber 27 rises. As a result, the pressure of the switching valve pressure chamber 14 propagated from the pressure chamber 27 via the pressure introduction passage 21, the switching valve housing 12, the hydraulic oil flow port 132 provided in the sub-cylinder 13, and the like also rises. As a result, the spool 11 housed in the sub-cylinder 13 moves to the left against the spring force of the spring 15 and comes to the position shown by the chain double-dashed line in FIG. As a result, the communication passage 23 connected to the second discharge port 31 ′ and the suction side passage 22 connected to the second suction port 41 ′ are blocked by the land 111 of the spool 11 provided in the sub-cylinder 13. The Rukoto. Therefore, the discharge oil discharged from the second discharge port 31 ′ is guided to the discharge port 81 of the sub-plate 8 through the discharge passage 33 as shown by the solid arrow in FIG. 1, where the valve 9 is opened to the pressure chamber 27. And flow. This increases the discharge capacity of the vane pump, which contributes to assisting the steering force of the power assist unit.

[0019]

[Effect of the device]

 According to the present invention, in a vane pump having a plurality of suction ports and discharge ports, when the load pressure of the power assisting device power assist section is low, the suction operation of the specific suction port and discharge port is performed. In a variable displacement vane pump device that has a switching valve that stops the pump function by circulating oil and when the load pressure rises, restores the pump function of the stopped part. In addition to the communication passage communicating with the switching valve, the second discharge port is also in operation in the specific discharge port (second discharge port) provided in the side plate that forms the pump function, and the pump function is restored. A discharge passage through which the discharge fluid flows is provided, and a large opening area is provided at the opening existing near the center of the rotation axis of this discharge passage. Since the configuration has a check valve consisting of an outlet and a valve mechanism that opens and closes the discharge port, when hydraulic oil circulates, the circulating hydraulic oil does not go through the check valve and the suction port side The energy loss due to the circulating action of hydraulic oil is reduced because it returns directly to the. Further, when the discharge oil is also discharged from the second discharge port in the high output state, the flow path of the discharge oil is shortened, and the discharge port is formed to have a large opening area. As a result, the flow resistance of the discharged oil has been reduced. From the above, according to the present invention, it is possible to further reduce the energy loss during the operation of the pump.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing the structure of a vane pump and a switching valve according to the present invention.

FIG. 2 is a view showing a structure of a side plate and a discharge passage provided in the side plate according to the present invention.

FIG. 3 is a vertical cross-sectional view showing a structure of a variable displacement vane pump device having a double structure type switching valve in a conventional example.

[Explanation of Codes] 1 Switching valve 11 Spool 111 Land 111 'Land 12 Switching valve housing 122 Cylinder chamber 13 Sub-cylinder 132 Hydraulic oil flow port 133 Sub-cylinder chamber 14 Switching valve pressure chamber 15 Spring 2 Housing 21 Pressure introduction path 22 Suction side Passage 23 Communication passage 26 Flow control valve 27 Pressure chamber 28 Suction chamber 29 Bypass passage 3 Side plate 31 First discharge port 31 'Second discharge port 33 Discharge passage 4 Side plate 41 First suction port 41' Second suction port 5 Cam ring 6 rotor 7 vane 8 sub-plate 81 discharge port 82 guide 9 valve 99 spring

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Creator Seiji Kawakami 1st Toyota Town, Toyota City, Aichi Prefecture Toyota Automobile Co., Ltd.

Claims (1)

[Scope of utility model registration request] 1. A rotor that is housed in a housing and driven to rotate, a vane that slides in a slit of the rotor, a cam ring that is outside the vane and forms a pump chamber with the rotor, the vane, and the like. Side plates on both sides of the rotor, vane, and cam ring that contribute to the formation of a pump chamber, a plurality of discharge ports provided on the side plate, and a plurality of suction ports provided near the circumferential ends of the cam ring and the side plate. When the discharge flow rate of discharge oil discharged from the vane pump including ports and the pressure chambers connected to the discharge ports exceeds a predetermined value,
A hydraulic pump device comprising a flow control valve for bypassing the excess discharge oil to a bypass passage communicating with the suction port, the suction side passage communicating with the suction port, and a specific discharge port among the discharge ports. In a variable displacement vane pump device having a communication passage that communicates with each other, and a switching valve that switches between a communication state and a cutoff state between the communication passage and the suction side passage, a plurality of discharges provided on the side plates are provided. In addition to the communication passage, a discharge passage through which a discharge fluid flows only when the communication passage and the suction-side passage are in a closed state is provided in a specific discharge port of the ports, and the rotation of the discharge passage is performed. A variable displacement type having a check valve including a plurality of discharge ports having a large opening area provided near the axis center line and a valve mechanism for opening and closing the discharge ports. Nponpu apparatus.