JP6867935B2 - Vane pump - Google Patents

Description

The present invention relates to a vane pump.

Patent Document 1 describes a vane pump including a rotor that is rotationally driven and a vane that slides in a slit of the rotor. Each vane is urged in the direction protruding from the slit by the pressure at the bottom of the slit that presses its base end and the centrifugal force that acts as the rotor rotates, and the tip slides against the inner peripheral surface of the cam ring. Get in touch. As the rotor rotates, the vanes that are in sliding contact with the inner peripheral surface of the cam ring reciprocate, causing the pump chamber to expand and contract, and hydraulic oil is supplied and discharged to the pump chamber.

Japanese Unexamined Patent Publication No. 11-230057

In such a conventional vane pump, if the stopped state continues, the vane arranged at the upper part falls into the slit due to gravity. Therefore, when the vane pump is started, the discharge port and the suction port communicate with each other through the opening between the tip of the vane that has fallen into the slit and the inner peripheral cam surface, so that there is a problem that the rise of the pump discharge pressure is delayed.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a vane pump in which the pump discharge pressure rises quickly when the vane pump is started.

The first invention is a vane pump, which comprises a rotor having a plurality of slits, a plurality of vanes slidably housed in the slits, and a cam ring having an inner peripheral cam surface in which the tip of the vane is slidably contacted. A first side member that contacts one side surface of the rotor and cam ring, a second side member that contacts the other side surface of the rotor and cam ring, a pump chamber defined by a vane adjacent to the rotor and cam ring, and a slit. It includes a back pressure chamber partitioned by the base end of the vane, and the first side member has a suction port for guiding the working fluid to the pump chamber and a discharge port for guiding the working fluid from the pump chamber. However, at least one of the first side member and the second side member has a back pressure opening that opens in the sliding contact surface that is in sliding contact with the rotor and communicates with the back pressure chamber, and the rotation of the rotor in the back pressure opening. At the end of the communication end side where the communication with the back pressure chamber ends, the vane is moved outward in the radial direction of the rotor as the rotor rotates by contacting the base end of the vane when the vane pump is started. It is characterized in that an extruding portion for pushing toward is provided.

In the first invention, when the vane pump is started, the vane that has fallen into the slit due to its own weight is forcibly extruded outward in the radial direction by the extrusion portion, and the extruded vane moves from the discharge port to the suction port. The flow of working fluid is restricted.

The second invention is characterized in that the extruded portion is formed so as to push out the base end portion of the vane outward in the radial direction of the rotor from the center in the width direction of the back pressure opening.

In the second invention, the amount of protrusion of the vane from the slit can be increased.

A third invention is characterized in that the back pressure opening has an inner arc surface formed in an arc shape along the circumferential direction of the rotor, and the extruded portion is continuously provided on the inner arc surface. ..

In the third invention, the base end portion of the vane that moves along the inner arc surface of the back pressure opening can be smoothly guided to the extruded portion as the rotor rotates.

In the fourth invention, the back pressure opening is provided so that the bottom of the back pressure chamber coincides with the inner arc surface, or the bottom of the back pressure chamber is located radially outside the rotor with respect to the inner arc surface. It is characterized by being formed.

In the fourth invention, the base end portion of the vane that has fallen into the slit due to its own weight easily comes into contact with the extruded portion.

In the fifth invention, the inner peripheral cam surface has a short diameter portion having a short diameter from the rotation center of the rotor, a major diameter portion having a longer diameter from the rotation center of the rotor than the minor diameter portion, and a minor diameter portion to a major diameter portion. The maximum extrusion position, which has a transition portion where the diameter from the center of rotation of the rotor gradually increases toward, and the vane is pushed out to the maximum in the radial direction by the extrusion portion, is within the suction region where the pump chamber expands. It is set within the region from the boundary position that is the boundary between the transition portion and the major diameter portion in the above to the communication start position where the pump chamber starts to communicate with the discharge port as the rotor rotates in the discharge region where the pump chamber contracts. It is characterized by that.

The sixth invention is characterized in that the maximum extrusion position is set within the region from the communication end position where the communication between the pump chamber and the suction port ends as the rotor rotates to the communication start position of the discharge port. ..

The seventh invention further includes a groove-shaped notch communicating with the discharge port, the notch is formed so that the opening area gradually increases in the rotation direction of the rotor, and the maximum extrusion position is set from the boundary position to the rotor. The pump chamber is set within the area up to the position where it begins to communicate with the notch as it rotates.

In the fifth to seventh inventions, the amount of protrusion of the vane from the slit can be increased, and the flow of the working fluid from the discharge port to the suction port can be more effectively restricted.

According to the present invention, it is possible to provide a vane pump in which the pump discharge pressure rises quickly when the vane pump is started.

It is sectional drawing of the vane pump which concerns on this embodiment. It is a top view of the main part of the vane pump in the state which the cover side side plate of the vane pump which concerns on this embodiment is removed. It is a top view of the body side side plate in the vane pump which concerns on this embodiment. FIG. 3 is an enlarged view of part IV of FIG. It is a figure which shows the stopped state of a vane pump, and shows how the vane has fallen into a slit. It is a figure which shows the state which the rotor started to rotate, and shows how the vane is pushed out in the radial direction by the inner inner peripheral surface of the back pressure groove. It is a figure which shows the state which the vane was pushed out to the outside in the radial direction by the inner inner peripheral surface of the back pressure groove. It is a figure explaining the region where the maximum extrusion position of a vane is set. FIG. 5 is a diagram showing a state in which the vane is pushed out to the maximum in the radial direction by the inner inner peripheral surface of the back pressure groove in the vane pump according to the first modification of the present embodiment. (A) is a diagram showing the positional relationship between the back pressure chamber and the back pressure groove of the vane pump according to the second modification of the present embodiment, and (b) shows a state in which the rotor is rotated by a predetermined amount from the state of (a). FIG. 6 shows how the base end portion of the vane comes into contact with the extruded surface of the back pressure groove as the rotor rotates. It is a top view of the body side side plate in the vane pump which concerns on the modification 3 of this embodiment.

Hereinafter, the vane pump according to the embodiment of the present invention will be described with reference to the drawings.

<First Embodiment>
The vane pump 100 according to the first embodiment of the present invention is used as a fluid pressure supply source for a fluid pressure device mounted on a vehicle, for example, a power steering device or a continuously variable transmission. The working fluid is oil, other water-soluble alternative solutions, and the like.

As shown in FIGS. 1 and 2, the vane pump 100 includes a pump body 10 in which a pump accommodating recess 10A is formed, a pump cover 20 that covers an opening of the pump accommodating recess 10A and is fixed to the pump body 10, and a pump. A drive shaft 1 rotatably supported by the body 10 and the pump cover 20 via bearings 11 and 12, a rotor 2 connected to the drive shaft 1 and housed in the pump accommodating recess 10A, and a slit 2A of the rotor 2 are slid. It includes a vane 3 that is movably housed, and a cam ring 4 that accommodates the rotor 2 and the vane 3 and has an inner peripheral cam surface 4a that the tip portion 3a of the vane 3 is in sliding contact with.

The vane pump 100 is driven by, for example, a drive device (not shown) such as an engine, and a rotor 2 connected to a drive shaft 1 is rotationally driven clockwise as shown by an arrow in FIG. 2 to generate a fluid pressure. Let me.

A plurality of slits 2A are formed radially in the rotor 2. The slit 2A has an opening 2a on the outer periphery of the rotor 2.

The vane 3 is slidably inserted into each slit 2A, and has a tip portion 3a which is an end portion in a direction protruding from the slit 2A and a base end portion 3b which is an end portion opposite to the tip portion 3a. Have. On the bottom side of the slit 2A, the back pressure chamber 5 is partitioned in the slit 2A by the base end portion 3b of the vane 3. Hydraulic oil as a hydraulic fluid is guided into the back pressure chamber 5. The vane 3 is pressed in the direction of protruding from the slit 2A by the pressure of the back pressure chamber 5. The adjacent back pressure chambers 5 are communicated with each other by a communication groove 2b provided on the end surface of the rotor 2.

The cam ring 4 is an annular member having an inner peripheral cam surface 4a which is a substantially oval-shaped inner peripheral surface and a pin hole 4b through which a positioning pin 8 is inserted. When the vane 3 is pressed in the direction of protruding from the slit 2A by the pressure of the back pressure chamber 5, the tip portion 3a of the vane 3 slides into contact with the inner peripheral cam surface 4a of the cam ring 4. As a result, the pump chamber 6 is defined inside the cam ring 4 by the outer peripheral surface of the rotor 2, the inner peripheral cam surface 4a of the cam ring 4, and the adjacent vanes 3.

The inner peripheral cam surface 4a has a minor axis portion 141 having a shorter diameter from the rotation center axis O of the rotor 2 and a major axis portion 143 having a larger diameter from the rotation center axis O of the rotor 2 than the minor axis portion 141. It has a transition portion 142 in which the diameter of the rotor 2 from the rotation center axis O gradually increases from the portion 141 to the major diameter portion 143.

Since the inner peripheral cam surface 4a of the cam ring 4 has a substantially oval shape, the volume of the pump chamber 6 partitioned by the vanes 3 that slide in contact with the inner peripheral cam surface 4a as the rotor 2 rotates expands and contracts. And repeat. The hydraulic oil is sucked in the suction region where the pump chamber 6 expands, and the hydraulic oil is discharged in the discharge region where the pump chamber 6 contracts.

As shown in FIG. 2, the vane pump 100 includes a first suction region and a first discharge region in which the vane 3 makes a first reciprocating movement, and a second suction region in which the vane 3 makes a second reciprocating movement. It has a second discharge area. The pump chamber 6 expands in the first suction region, contracts in the first discharge region, expands in the second suction region, and expands into the second discharge region while the rotor 2 makes one rotation. Shrinks. The vane pump 100 has two suction regions and two discharge regions, but is not limited to this, and may be configured to have one or three or more suction regions and one or three or more discharge regions.

As shown in FIG. 1, the vane pump 100 is provided on one end side in the axial direction of the rotor 2, and has a body side side plate 30 as a first side member that abuts on one side surface of the rotor 2 and the cam ring 4, and the rotor 2. A cover-side side plate 40 as a second side member, which is provided on the other end side in the axial direction and abuts on the other side surface of the rotor 2 and the cam ring 4, is further provided.

The body side side plate 30 is provided between the bottom surface of the pump accommodating recess 10A and the rotor 2. One end surface in the axial direction of the rotor 2 is in sliding contact with the side plate 30 on the body side, and one end surface in the axial direction of the cam ring 4 is in contact with the side plate 30. The cover side side plate 40 is provided between the rotor 2 and the pump cover 20. The other end surface of the rotor 2 in the axial direction is in sliding contact with the side plate 40 on the cover side, and the other end surface in the axial direction of the cam ring 4 is in contact with the side plate 40. In this way, the body-side side plate 30 and the cover-side side plate 40 are arranged so as to face both side surfaces of the rotor 2 and the cam ring 4.

The body-side side plate 30, the rotor 2, the cam ring 4, and the cover-side side plate 40 are housed in the pump housing recess 10A of the pump body 10. In this state, the pump cover 20 is attached to the pump body 10 to seal the pump accommodating recess 10A.

An annular high pressure chamber 14 partitioned by the pump body 10 and the body side side plate 30 is formed on the bottom surface side of the pump accommodating recess 10A of the pump body 10. The high pressure chamber 14 communicates with the fluid pressure device 70 outside the vane pump 100 through the discharge passage 62.

A suction pressure chamber 21 is formed in the pump cover 20, and a detour passage 13 communicating with the suction pressure chamber 21 is formed on the inner peripheral surface of the pump accommodating recess 10A. The detour passage 13 is provided at two positions facing each other with the cam ring 4 in between. The suction pressure chamber 21 is connected to the tank 60 via a suction passage 61.

As shown in FIG. 3, the body-side side plate 30 includes a sliding contact surface 30a that is in sliding contact with the side surface of the rotor 2, a discharge port 31 that is formed so as to correspond to each of the first and second discharge regions. A plate-shaped member having a through hole 32 through which the drive shaft 1 is inserted, a suction port 33 formed so as to correspond to each of the first and second suction regions, and a pin hole 39 through which the positioning pin 8 is inserted. Is.

The discharge ports 31 are provided at two positions facing each other with the through hole 32 interposed therebetween. Each discharge port 31 is formed in an arc shape centered on the through hole 32. The discharge port 31 penetrates the body side side plate 30 and communicates with the high pressure chamber 14 formed in the pump body 10. The discharge port 31 guides hydraulic oil from the pump chamber 6 and discharges the guided hydraulic oil to the high pressure chamber 14. The hydraulic oil that has flowed into the high-pressure chamber 14 is supplied to the fluid pressure device 70 outside the vane pump 100 through the discharge passage 62 (see FIG. 1).

The suction ports 33 are provided at two positions facing each other with the through hole 32 interposed therebetween. The suction port 33 is formed at a position corresponding to the bypass passage 13 of the pump accommodating recess 10A. Each suction port 33 is formed so as to have a concave shape that opens outward in the radial direction. The outer peripheral end of each suction port 33 reaches the outer peripheral surface of the body side side plate 30. Hydraulic oil is supplied to the suction port 33 through the suction pressure chamber 21 and the bypass passage 13 (see FIG. 1), and the suction port 33 guides the supplied hydraulic oil into the pump chamber 6.

A groove-shaped outer notch 37 and an inner notch 36 are formed on the sliding contact surface 30a of the body side side plate 30. The outer notch 37 and the inner notch 36 are provided at the end of the discharge port 31 on the communication start side where the pump chamber 6 starts communicating with the rotation of the rotor 2, and communicate with the discharge port 31. The outer notch 37 and the inner notch 36 are formed so that the opening area gradually increases in the rotation direction of the rotor 2. The outer notch 37 is arranged on the outer peripheral side of the inner notch 36, and is formed so that the length of the rotor 2 in the rotational direction is shorter than that of the inner notch 36.

The outer notch 37 and the inner notch 36 are arranged between the outer peripheral surface of the rotor 2 and the inner peripheral cam surface 4a of the cam ring 4 (see FIG. 2). The formation of the outer notch 37 and the inner notch 36 promotes the flow of hydraulic oil from the pump chamber 6 to the discharge port 31 through the outer notch 37 and the inner notch 36 as the rotor 2 rotates. 14 sudden pressure fluctuations are prevented.

A pair of back pressure grooves 34 formed so as to face each other across the through hole 32 and a pair of back pressure grooves formed so as to face each other across the through hole 32 on the sliding contact surface 30a of the body side side plate 30. It has an indentation groove 35 and. The pair of back pressure grooves 35 are provided at positions deviated from the pair of back pressure grooves 34 by approximately 90 ° with respect to the through hole 32. The back pressure groove 34 is provided in each of the first and second suction regions, and the back pressure groove 35 is provided in each of the first and second discharge regions.

The back pressure grooves 34 and 35 are formed in a groove shape that opens in the sliding contact surface 30a. The back pressure grooves 34 and 35 are formed in an arc shape centered on the through hole 32, and communicate with a plurality of back pressure chambers 5 overlapping the back pressure grooves 34 and 35. The back pressure groove 34 communicates with the communication hole 38 formed through the body side side plate 30. As a result, the back pressure groove 34 communicates with the high pressure chamber 14 through the communication hole 38 (see FIG. 1). Since each back pressure chamber 5 communicates with the communication groove 2b (see FIG. 2), the back pressure groove 35 communicates with the back pressure groove 34 via the back pressure chamber 5 and the communication groove 2b. That is, the back pressure groove 35 communicates with the high pressure chamber 14 via the back pressure chamber 5, the communication groove 2b, and the back pressure groove 34.

As shown in FIG. 1, the cover-side side plate 40 corresponds to the sliding contact surface 40a that is in sliding contact with the side surface of the rotor 2 and the first and second suction regions, respectively, like the body-side side plate 30. It is a plate-shaped member having a suction port 41 to be formed, a through hole 42 through which the drive shaft 1 is inserted, and a pin hole (not shown) through which the positioning pin 8 is inserted. The cover-side side plate 40 is positioned with respect to the cam ring 4 and the body-side side plate 30 by the positioning pin 8.

The suction ports 41 are provided at two positions facing each other with the through hole 42 in between. Each suction port 41 is formed so as to cut out a part of the outer edge portion of the cover side side plate 40. The suction port 41 communicates with the suction pressure chamber 21 formed in the pump cover 20. The suction port 41 guides the hydraulic oil supplied from the suction pressure chamber 21 into the pump chamber 6.

On the sliding contact surface 40a of the cover side side plate 40, a pair of back pressure grooves (not shown) formed so as to face the pair of back pressure grooves 35 of the body side side plate 30 described above, and the body side described above. It has a pair of back pressure grooves 44 formed so as to face the pair of back pressure grooves 34 of the side plate 30. Since each back pressure groove provided on the sliding contact surface 40a of the cover side side plate 40 has the same configuration as the back pressure groove provided on the body side side plate 30, the description thereof will be omitted.

Next, the operation of the vane pump 100 will be described.

When the drive shaft 1 is rotationally driven by the power of a drive device (not shown) such as an engine, the rotor 2 rotates in the direction indicated by the arrow in FIG. As the rotor 2 rotates, the pump chambers 6 located in the first and second suction regions expand. As a result, the hydraulic oil in the tank 60 is sucked into the pump chamber 6 through the suction passage 61, the suction pressure chamber 21, the suction port 41 and the suction port 33, as shown by the arrows in FIG. Further, as the rotor 2 rotates, the pump chambers 6 located in the first and second discharge regions contract. As a result, the hydraulic oil in the pump chamber 6 is discharged to the high pressure chamber 14 through the discharge port 31. The hydraulic oil discharged to the high pressure chamber 14 is supplied to the external fluid pressure device 70 through the discharge passage 62. In the vane pump 100 according to the present embodiment, each pump chamber 6 repeatedly sucks and discharges hydraulic oil twice while the rotor 2 makes one rotation.

A part of the hydraulic oil discharged to the high pressure chamber 14 is supplied to the back pressure chamber 5 through the communication hole 38 and the back pressure groove 34, and presses the base end portion 3b of the vane 3 toward the inner peripheral cam surface 4a. Therefore, the vane 3 is urged in the direction of protruding from the slit 2A by the fluid pressure of the back pressure chamber 5 that presses the base end portion 3b and the centrifugal force that acts with the rotation of the rotor 2. As a result, the tip portion 3a of the vane 3 rotates while sliding in contact with the inner peripheral cam surface 4a of the cam ring 4, so that the hydraulic oil in the pump chamber 6 is the tip portion 3a of the vane 3 and the inner peripheral cam surface 4a of the cam ring 4. It is discharged from the discharge port 31 without leaking from between.

As shown in FIG. 2, the vane pump 100 is mounted on a vehicle or the like so that the first suction region is located vertically above and the second suction region is located vertically below.

When the vane pump 100 continues to be stopped, a part of the hydraulic oil in the vane pump 100 flows down to the tank 60, and the pressure in the back pressure chamber 5 also decreases. In the first suction region, the opening surface of the slit 2A faces upward. Therefore, in the first suction region, the vane 3 falls into the bottom of the slit 2A due to gravity (see FIG. 5).

In this state, the discharge port 31 and the suction port 33 communicate with each other through the opening between the tip of the vane 3 that has fallen into the slit 2A and the inner peripheral cam surface 4a. Therefore, when the vane pump 100 is started, the discharge pressure generated by the pump chamber 6 that moves from the second suction region to the second discharge region at the lower part of the vane pump 100 shown in FIG. 2 is the discharge pressure of the first discharge region. It escapes from the discharge port 31 to the suction port 33 in the first suction region. Therefore, when the vane pump 100 is started, if it takes a long time for the vane 3 that has fallen into the slit 2A to protrude from the slit 2A, there arises a problem that the rise of the pump discharge pressure is delayed.

Therefore, in the present embodiment, the vane 3 is moved outward in the radial direction of the rotor 2 as the rotor 2 rotates in the back pressure groove 34 arranged in the suction region so that the depressed vane 3 is quickly projected. An extruded surface 184 forcibly extruded toward the surface was provided. Since the back pressure groove 34 formed in the body side side plate 30 and the back pressure groove 44 formed at the position facing the back pressure groove 34 in the cover side side plate 40 have the same shape, the body is hereinafter referred to as a body. The shape of the back pressure groove 34 of the side side plate 30 will be described in detail on behalf of the back pressure groove 34.

As shown in FIG. 3, the back pressure groove 34 has a bottom surface provided with a communication hole 38 and an inner peripheral surface (side surface of the groove) rising from the bottom surface. The inner peripheral surface of the back pressure groove 34 has an inner inner peripheral surface 181 facing outward in the radial direction of the rotor 2 and an outer inner peripheral surface 182 facing inward in the radial direction of the rotor 2, and has a sliding contact surface 30a. It is provided in.

One end of the inner inner peripheral surface 181 is connected to one end of the outer inner peripheral surface 182 at the starting end X of the back pressure groove 34. The other end of the inner inner peripheral surface 181 is connected to the other end of the outer inner peripheral surface 182 at the end P0 of the back pressure groove 34. The start end X of the back pressure groove 34 is a position in the back pressure groove 34 where communication with the back pressure chamber 5 starts as the rotor 2 rotates. The end P0 of the back pressure groove 34 is a position in the back pressure groove 34 where communication with the back pressure chamber 5 ends as the rotor 2 rotates.

As shown in FIG. 4, the central surface C1 in the width (diametrical length) direction of the back pressure groove 34 extends along the rotation direction of the rotor 2 and passes through the start end X (see FIG. 3).

The inner inner peripheral surface 181 of the back pressure groove 34 is the inner arc surface 183 formed in an arc shape along the circumferential direction of the rotor 2 and the end point P0 of the back pressure groove 34 continuous from the end point P1 of the inner arc surface 183. It has an arcuate extruded surface 184 that extends to. As described above, the extrusion surface 184 is provided at the end of the back pressure groove 34 on the communication end side where the communication with the back pressure chamber 5 ends with the rotation of the rotor 2.

The inner arcuate surface 183 is an arcuate surface centered on the rotation center axis O of the rotor 2, and the extruded surface 184 is an arcuate surface whose center is located radially outside the rotor 2 with respect to the inner arcuate surface 183. Is.

The outer inner peripheral surface 182 of the back pressure groove 34 is the outer arc surface 185 formed in an arc shape along the circumferential direction of the rotor 2 and the end point P0 of the back pressure groove 34 continuous from the end point P2 of the outer arc surface 185. It has an arcuate outer connecting surface 186 extending to. The outer arcuate surface 185 is an arcuate surface centered on the rotation center axis O of the rotor 2, and the outer connecting surface 186 is an arcuate surface whose center is located in the back pressure groove 34.

The extruded surface 184 is formed so that the distance from the rotation center axis O gradually increases from the end point P1 of the inner arc surface 183 to the end P0 of the back pressure groove 34 along the rotation direction. The end P0 of the back pressure groove 34 is also the end of the extrusion surface 184, and is located closer to the outer arc surface 185 than the inner arc surface 183, that is, in the radial direction of the rotor 2 than the central surface C1 in the width direction of the back pressure groove 34. Set to the outer position.

That is, the extrusion surface 184 is formed so as to push out the base end portion 3b of the vane 3 outward in the radial direction of the rotor 2 from the central surface C1 in the width direction of the back pressure groove 34. As a result, the amount of protrusion of the vane 3 from the slit 2A can be increased as compared with the case where the end of the extrusion surface 184 is set inside the rotor 2 in the radial direction with respect to the central surface C1 in the width direction of the back pressure groove 34.

The back pressure groove 34 is formed so that the bottom portion 5c (bottom portion of the slit 2A) of the back pressure chamber 5 coincides with the inner arc surface 183 (see FIG. 5). That is, the distance (diameter length) from the rotation center axis O of the rotor 2 to the bottom portion 5c of the back pressure chamber 5 and the radius of the inner arc surface 183 are set to the same dimensions.

The operation of the vane 3 at the time of starting the vane pump 100 according to the present embodiment will be described with reference to FIGS. 5 to 7. In FIGS. 5 to 7, the back pressure groove 34 hidden by the rotor 2 is shown by a solid line so that the positional relationship between the back pressure groove 34 and the vane 3 can be understood, and the back pressure groove 34 is extruded by the extrusion surface 184 (hereinafter referred to as vane 3). , Vane 3C) is hatched. The point Q represents the contact point between the vane 3C and the back pressure groove 34.

A slight gap is formed between each vane 3 and the side plates 30 and 40. Since the rotation center axis O of the vane pump 100 mounted on a vehicle or the like rarely coincides completely horizontally, each vane 3 is one of a pair of side plates 30 and 40 when the vehicle or the like is stopped. It is tilted to fall down.

For example, when the vane 3C is tilted and its base end portion 3b is depressed into the back pressure groove 34 of the body side side plate 30, as shown in FIG. 5, the base end portion 3b of the depressed vane 3 is depressed into the back pressure groove. It is caught on the inner arc surface 183 of 34 (see contact point Q).

When the vane pump 100 is started, the drive device (not shown) is driven and the rotor 2 starts to rotate. As shown in FIG. 6, the base end portion 3b of the vane 3C is along the inner arc surface 183 of the back pressure groove 34. Is guided from the inner arc surface 183 to the extruded surface 184 (see contact point Q).

Since the extruded surface 184 is continuously provided on the inner arc surface 183, the base end portion 3b of the vane 3C in contact with the inner arc surface 183 of the back pressure groove 34 is smoothly guided to the extruded surface 184. Can be done.

When the base end portion 3b of the vane 3C is guided to the extrusion surface 184, the base end portion 3b of the vane 3C is extruded radially outward by the contacting extrusion surface 184 as the rotor 2 rotates. .. When the rotor 2 further rotates, the vane 3C is pushed out to the maximum in the radial direction as shown in FIG. In the present embodiment, when the contact point Q of the base end portion 3b of the vane 3C with respect to the extruded surface 184 is located at the end P0, the vane 3C is pushed out to the maximum in the radial direction.

The maximum extrusion position where the vane 3C is pushed out to the maximum radially outward by the extrusion surface 184 is the end of communication in the first suction region where the communication between the pump chamber 6 and the suction port 33 ends with the rotation of the rotor 2. It is set to position B3.

Further, in the present embodiment, the extrusion surface 184 is formed so that the tip portion 3a of the vane 3C comes into contact with the inner peripheral cam surface 4a at the maximum extrusion position. Therefore, when the vane 3 is pushed out to the maximum in the radial direction, the flow of hydraulic oil from the discharge port 31 to the suction port 33 is blocked by the vane 3C.

As a result, the discharge pressure generated by the pump chamber 6 moving from the second suction region to the second discharge region at the lower part of the vane pump 100 shown in FIG. 2 is transferred from the discharge port 31 of the first discharge region to the second. It is possible to prevent the suction port 33 in one suction area from escaping.

In the second discharge region, the discharge pressure generated by the pump chamber 6 is held without escaping, so that the pressure in each back pressure chamber 5 rises and another vane 3 (for example, a vane) that has fallen into the slit 2A. The vane 3) located next to 3C is urged outward in the radial direction by the pressure in the back pressure chamber 5 and the centrifugal force acting with the rotation of the rotor 2, and the tip portion 3a thereof is the inner peripheral cam surface. It slides into 4a.

As a result, each pump chamber 6 expands and contracts normally, and the pump discharge pressure rises to a desired pressure in a short time.

A region for setting the maximum extrusion position of the vane 3C will be described with reference to FIG. Regions A1 to A5 are regions set along the circumferential direction of the rotor 2.

(Comparative Example 1)
When the maximum extrusion position of the vane 3C is set in the region A1 The region A1 is the inner peripheral cam from the boundary position B1 between the short diameter portion 141 and the transition portion 142 of the inner peripheral cam surface 4a in the first suction region. This is the region up to the boundary position B2 between the transition portion 142 of the surface 4a and the major axis portion 143. That is, the region A1 is a region corresponding to the transition portion 142 of the inner peripheral cam surface 4a.

When the maximum extrusion position is set in the region A1, the amount of protrusion of the vane 3C is limited by the inner peripheral cam surface 4a. Therefore, after the vane 3 is extruded by the extruded surface 184 and the tip portion 3a comes into contact with the inner peripheral cam surface 4a, a large gap is formed between the tip portion 3a and the inner peripheral cam surface 4a as the rotor 2 rotates. It may be formed.

(Example 1)
When the maximum extrusion position of the vane 3C is set in the region A2 In the first suction region, the region A2 rotates the rotor 2 from the boundary position B2 between the transition portion 142 and the major axis portion 143 of the inner peripheral cam surface 4a. This is the area up to the communication end position B3 where the communication between the pump chamber 6 and the suction port 33 ends. That is, the region A2 is a region corresponding to the long diameter portion 143 of the inner peripheral cam surface 4a and a region corresponding to the suction port 33.

In the first embodiment in which the maximum extrusion position is set in the region A2, the amount of protrusion of the vane 3 at the maximum extrusion position can be increased as compared with the comparative example 1 in which the maximum extrusion position is set in the region A1. By setting the maximum extrusion position of the vane 3 to the major axis portion 143, a gap is formed between the tip portion 3a and the inner peripheral cam surface 4a after the tip portion 3a of the vane 3 comes into contact with the inner peripheral cam surface 4a. Can be prevented. Therefore, in the first embodiment, the pump discharge pressure can be raised more quickly when the vane pump 100 is started, as compared with the comparative example 1 in which the maximum extrusion position is set in the region A1.

(Comparative Example 2)
When the maximum extrusion position of the vane 3C is set in the area A5 The area A5 starts from the communication start position B5 where the pump chamber 6 starts communicating with the discharge port 31 as the rotor 2 rotates in the first discharge area. This is the area up to the communication end position B6 where the communication between the pump chamber 6 and the discharge port 31 ends as the rotor 2 rotates. That is, the area A5 is an area corresponding to the discharge port 31.

When the maximum extrusion position is set in the region A5, the discharge port 31 and the suction port 33 communicate with each other when the vane 3 is pushed out to the maximum in the radial direction. That is, in the second discharge region, the discharge pressure generated by the pump chamber 6 escapes to the suction port 33 in the first suction region through the discharge port 31 in the first discharge region.

(Example 2)
When the maximum extrusion position of the vane 3C is set in the area A4 The area A4 discharges from the communication start position B4 in which the pump chamber 6 starts communicating with the notch 36 as the rotor 2 rotates in the first discharge area. This is the area up to the communication start position B5 of the port 31. That is, the region A4 is a region corresponding to the notch 36.

When the maximum extrusion position is set in the region A4, the discharge port 31 communicates with the suction port 33 via the notch 36 when the vane 3 is pushed out to the maximum in the radial direction. However, the notch 36 has a small flow path cross-sectional area of the hydraulic oil, and a large passage resistance acts on the hydraulic oil passing through the notch 36. Therefore, in the second embodiment, the pump discharge pressure can be increased more quickly when the vane pump 100 is started, as compared with the second embodiment in which the maximum extrusion position is set in the region A5.

(Example 3)
When the maximum extrusion position of the vane 3C is set in the region A3 The region A3 is a region from the communication end position B3 of the suction port 33 provided in the first suction region to the communication start position B4 of the notch 36.

In the first embodiment in which the maximum extrusion position is set in the region A2, the vane 3C is pushed out to the maximum in the radial direction and then slightly returns to the inside of the slit 2A due to its own weight before reaching the communication end position B3. There is a risk. Further, in the second embodiment in which the maximum extrusion position is set in the region A4, the discharge port 31 and the suction port 33 communicate with each other through the notch 36.

On the other hand, in the third embodiment in which the maximum extrusion position is set in the region A3, the communication between the discharge port 31 and the suction port 33 is cut off when the vane 3 is pushed out to the maximum in the radial direction. To. Therefore, the pump discharge pressure can be raised more effectively than in the first embodiment in which the maximum extrusion position is set in the region A2.

From Examples 1 to 3 and Comparative Examples 1 and 2, the maximum extrusion position of the vane 3C is a region from the boundary position B2 between the transition portion 142 and the major axis portion 143 to the communication start position B5 of the discharge port 31 (regions A2 to A2). It is preferable to set it in A4). Further, it is more preferable to set it on the rotation direction side of the rotor 2 than the communication end position B3 of the suction port 33, and further, it is more preferable to set it on the rotation opposite direction side of the rotor 2 than the communication start position B4 of the notch 36. preferable.

According to the above embodiment, the following effects are obtained.

In the vane pump 100 according to the present embodiment, at the end of the back pressure groove 34 on the end side of the communication end side where the communication with the back pressure chamber 5 ends with the rotation of the rotor 2, the base end of the vane 3 when the vane pump 100 is started. By contacting the portion 3b, an extruded surface 184 that pushes the vane 3 outward in the radial direction of the rotor 2 as the rotor 2 rotates is provided.

Therefore, when the vane pump 100 is started, the vane 3C in a state of being depressed into the slit 2A due to its own weight is forcibly pushed out radially outward by the extrusion surface 184, and the hydraulic oil from the discharge port 31 to the suction port 33. Flow is restricted. That is, the discharge pressure generated in the second discharge region is prevented from escaping to the first suction region through the first discharge region.

Since the discharge pressure generated in the second discharge region is held without escaping, the pressure in each back pressure chamber 5 rises, and each vane 3 that has fallen into each slit 2A due to the pressure in each back pressure chamber 5 It quickly protrudes from each slit 2A, and the tip portion 3a of each vane 3 slides into contact with the inner peripheral cam surface 4a. As a result, each pump chamber 6 expands and contracts normally, and the pump discharge pressure rises to a desired pressure in a short time. That is, according to the present embodiment, the pump discharge pressure can be quickly increased when the vane pump 100 is started.

The following modifications are also within the scope of the present invention, and it is possible to combine the configurations shown in the modifications with the configurations described in the above-described embodiments, or to combine the configurations described in the following different modifications. Is.

(Modification example 1)
In the above embodiment, an example in which the tip portion 3a of the vane 3C comes into contact with the inner peripheral cam surface 4a when the contact point Q of the base end portion 3b of the vane 3C with respect to the extrusion surface 184 is located at the end P0 has been described. The present invention is not limited to this. As shown in FIG. 9, when the contact point Q of the base end portion 3b of the vane 3C with respect to the extruded surface 184 is located at the end P0, a gap is formed between the tip portion 3a of the vane 3C and the inner peripheral cam surface 4a. It may have been. By sufficiently projecting the vane 3C, the passage resistance of the hydraulic oil passing through the gap between the tip portion 3a of the vane 3C and the inner peripheral cam surface 4a can be increased. As a result, the front-rear differential pressure (discharge side pressure-suction side pressure) of the vane 3C can be increased.

As described above, in the present modification 1, when the vane pump 100 is started, the vane 3C in a state of being depressed into the slit 2A due to its own weight is forcibly pushed out radially outward by the extrusion surface 184 and sucked from the discharge port 31. The flow of hydraulic oil to the port 33 is restricted. As a result, it is possible to prevent the discharge pressure generated in the second discharge region from escaping to the suction port 33 in the first suction region through the discharge port 31 in the first discharge region. Therefore, according to the first modification, the pump discharge pressure can be quickly increased when the vane pump 100 is started, as in the above embodiment.

(Modification 2)
In the above embodiment, an example in which the back pressure groove 34 is formed so that the bottom portion 5c of the back pressure chamber 5 coincides with the inner arc surface 183 has been described, but the present invention is not limited thereto. As shown in FIG. 10A, the bottom portion 5c of the back pressure chamber 5 may be formed so as to be located radially outside the rotor 2 with respect to the inner arc surface 183.

In the second modification, the base end portion 3b of the vane 3C, which has fallen into the bottom portion 5c of the back pressure chamber 5 due to its own weight, does not contact the inner arc surface 183. When the rotor 2 rotates when the vane pump 100 is started, the extrusion surface 184 and the bottom surface of the back pressure chamber 5 overlap each other as shown in FIG. 10B, and the base end portion 3b of the vane 3C comes into contact with the extrusion surface 184. .. As a result, the vane 3C is forcibly pushed out radially outward by the extrusion surface 184.

On the other hand, when the bottom portion 5c of the back pressure chamber 5 is located radially inside the rotor 2 with respect to the inner arc surface 183 (not shown), when the vane 3C falls due to its own weight, the back pressure does not get caught on the inner arc surface 183. It may drop to the bottom 5c of the chamber 5. In this case, when the vane pump 100 is started, the base end portion 3b of the vane 3C does not come into contact with the extrusion surface 184 even if the rotor 2 rotates, so that the vane 3C cannot be extruded by the extrusion surface 184.

Therefore, in the back pressure groove 34, the bottom 5c of the back pressure chamber 5 coincides with the inner arc surface 183 (see FIG. 5), or the bottom 5c of the back pressure chamber 5 is closer to the rotor 2 than the inner arc surface 183. It is preferably formed so as to be located on the outer side in the radial direction (see FIG. 10A). As a result, the base end portion 3b of the vane 3 that has fallen into the slit 2A due to its own weight easily comes into contact with the extruded surface 184.

(Modification example 3)
The shape of the back pressure groove 34 is not limited to the above embodiment. For example, as shown in FIG. 11, a groove-shaped notch 280 having a shallow bottom may be formed at the end of the back pressure groove 34, and the inner inner peripheral surface of the notch 280 may be an extrusion surface 184.

(Modification example 4)
In the above embodiment, an example in which a plurality of back pressure grooves 34, 35, 44 are provided on both the body side side plate 30 and the cover side side plate 40 has been described, but the present invention is not limited thereto. A back pressure groove may be provided in at least one of the body side side plate 30 and the cover side side plate 40.

(Modification 5)
In the above embodiment, an example (see FIG. 3) in which the extrusion surface 184 is formed in the back pressure grooves 34 arranged in the first and second suction regions has been described, but the present invention is not limited thereto. The extrusion surface 184 may be formed only in the back pressure groove 34 arranged in the first suction region located above the vane pump 100 (see FIG. 11). By forming the extrusion surface 184 in the back pressure grooves 34 arranged in the first and second suction regions as in the above embodiment, the side plates 30 and 40 can be assembled even if they are turned upside down. , The degree of freedom of assembly is improved.

(Modification 6)
In the above embodiment, the back pressure grooves 34, 35, 44 are not limited to being formed in a groove shape, and may be formed as through holes.

(Modification 7)
In the above embodiment, an example in which the pair of side plates 30 and 40 are provided has been described, but the present invention is not limited thereto. For example, the cover side side plate 40 may be integrally molded with the pump cover 20. In this case, the pump cover 20 functions as a side member that abuts on the side surfaces of the rotor 2 and the cam ring 4.

The configuration, operation, and effect of the embodiment of the present invention configured as described above will be collectively described.

The vane pump 100 has a plurality of radially formed slits 2A, and a rotor 2 driven to rotate, a plurality of vanes 3 slidably housed in the slits 2A, and a tip portion 3a of the vane 3 slide. A cam ring 4 having an inner peripheral cam surface 4a in contact, a body side side plate 30 that abuts on one side surface of the rotor 2 and the cam ring 4, and a cover side side plate 40 that abuts on the other side surface of the rotor 2 and the cam ring 4. The body side side plate 30 includes a pump chamber 6 defined by a rotor 2 and a vane 3 adjacent to the cam ring 4, and a back pressure chamber 5 partitioned by a base end portion 3b of the vane 3 in the slit 2A. Has a suction port 33 for guiding hydraulic oil to the pump chamber 6 and a discharge port 31 for guiding hydraulic oil from the pump chamber 6, and at least one of the body side side plate 30 and the cover side side plate 40 is a rotor. It has a back pressure groove 34 that opens in the sliding contact surfaces 30a and 40a that are in sliding contact with 2 and communicates with the back pressure chamber 5, and the communication with the back pressure chamber 5 in the back pressure groove 34 as the rotor 2 rotates. At the end on the end side of the end of communication, when the vane pump 100 is started, the vane 3 comes into contact with the base end 3b of the vane 3 to push the vane 3 outward in the radial direction as the rotor 2 rotates. An extruded surface 184 is provided.

In this configuration, when the vane pump 100 is started, the vane 3 in a state of being depressed into the slit 2A due to its own weight is forcibly pushed out radially outward by the extrusion surface 184, and is pushed out from the discharge port 31 by the extruded vane 3. The flow of hydraulic oil to the suction port 33 is restricted. Therefore, when the vane pump 100 is started, the pump discharge pressure can be quickly increased.

The vane pump 100 is formed so that the extrusion surface 184 pushes the base end portion 3b of the vane 3 outward in the radial direction of the rotor 2 from the central surface C1 in the width direction of the back pressure groove 34.

In this configuration, the amount of protrusion of the vane 3 from the slit 2A can be increased.

In the vane pump 100, the back pressure groove 34 has an inner arc surface 183 formed in an arc shape along the circumferential direction of the rotor 2, and the extrusion surface 184 is continuously provided on the inner arc surface 183.

In this configuration, the base end portion 3b of the vane 3 that moves along the inner arc surface 183 of the back pressure groove 34 can be smoothly guided to the extrusion surface 184 as the rotor 2 rotates.

The back pressure chamber 100 is backed so that the bottom of the back pressure chamber 5 coincides with the inner arc surface 183, or the bottom 5c of the back pressure chamber 5 is located radially outside the rotor 2 with respect to the inner arc surface 183. The indentation groove 34 is formed.

In this configuration, the base end portion 3b of the vane 3 that has fallen into the slit 2A due to its own weight easily comes into contact with the extruded surface 184.

In the vane pump 100, the inner peripheral cam surface 4a has a short diameter portion 141 having a shorter diameter from the rotation center axis O of the rotor 2 and a major diameter portion 143 having a longer diameter from the rotation center axis O of the rotor 2 than the minor diameter portion 141. And a transition portion 142 in which the diameter of the rotor 2 from the rotation center axis O gradually increases from the minor diameter portion 141 to the major diameter portion 143, and the vane 3 is maximized radially outward by the extrusion surface 184. The maximum extrusion position extruded to is from the boundary position B2, which is the boundary between the transition portion 142 and the major diameter portion 143 in the suction region where the pump chamber 6 expands, to the rotation of the rotor 2 in the discharge region where the pump chamber 6 contracts. Along with this, the pump chamber 6 is set within the region up to the communication start position B5 where the pump chamber 6 starts communicating with the discharge port 31.

The maximum extrusion position of the vane pump 100 is set within the region from the communication end position B3 where the communication between the pump chamber 6 and the suction port 33 ends with the rotation of the rotor 2 to the communication start position B5 of the discharge port 31.

The vane pump 100 further includes a groove-shaped notch 36 communicating with the discharge port 31, and the notch 36 is formed so that the opening area gradually increases in the rotation direction of the rotor 2, and the maximum extrusion position is the boundary position. The pump chamber 6 is set in the area from B2 to the communication start position B4 where the pump chamber 6 starts communicating with the notch 36 as the rotor 2 rotates.

With these configurations, the amount of protrusion of the vane 3 from the slit 2A can be increased, and the flow of hydraulic oil from the discharge port 31 to the suction port 33 can be more effectively restricted.

Although the embodiments of the present invention have been described above, the above embodiments are only a part of the application examples of the present invention, and the technical scope of the present invention is limited to the specific configurations of the above embodiments. Absent.

2 ... rotor, 2A ... slit, 3,3C ... vane, 3a ... tip, 3b ... base end, 4 ... cam ring, 4a ... inner cam surface, 5 ... Back pressure chamber, 5c ... Bottom, 6 ... Pump chamber, 30 ... Body side side plate (first side member), 30a ... Sliding contact surface, 31 ... Discharge port (Discharge port), 33 ... Suction port (suction port), 34 ... Back pressure groove (back pressure opening), 36 ... Notch, 40 ... Cover side side plate (second side member) , 40a ... sliding contact surface, 44 ... back pressure groove (back pressure opening), 100 ... vane pump, 141 ... short diameter part, 142 ... transition part, 143 ... long diameter part , 183 ... Inner arc surface, 184 ... Extruded surface (extruded part)

Claims (7)

It ’s a vane pump,
A rotor that has multiple slits formed radially and is driven to rotate,
A plurality of vanes slidably housed in the slit,
A cam ring having an inner cam surface with which the tip of the vane is in sliding contact,
A first side member that abuts on one side of the rotor and the cam ring,
A second side member that abuts on the rotor and the other side of the cam ring,
A pump chamber defined by the rotor and the vanes adjacent to the cam ring, and
A back pressure chamber, which is partitioned by the base end portion of the vane in the slit, is provided.
The first side member is
A suction port that guides the working fluid to the pump chamber,
It has a discharge port from which the working fluid is guided from the pump chamber.
At least one of the first side member and the second side member has a back pressure opening that opens in the sliding contact surface that is in sliding contact with the rotor and communicates with the back pressure chamber.
At the end of the back pressure opening on the end of communication where communication with the back pressure chamber ends with the rotation of the rotor, the vane base end is contacted when the vane pump is started. A vane pump characterized in that an extrusion portion for pushing the vane outward in the radial direction of the rotor is provided as the rotor rotates. In the vane pump according to claim 1,
The vane pump is characterized in that the extrusion portion is formed so as to push out the base end portion of the vane outward in the radial direction of the rotor from the center in the width direction of the back pressure opening. In the vane pump according to claim 1 or 2.
The back pressure opening has an inner arc surface formed in an arc shape along the circumferential direction of the rotor.
A vane pump characterized in that the extrusion portion is continuously provided on the inner arc surface. In the vane pump according to claim 3.
The back pressure opening is such that the bottom of the back pressure chamber coincides with the inner arc surface, or the bottom of the back pressure chamber is located radially outside the inner arc surface. A vane pump characterized by being formed. In the vane pump according to any one of claims 1 to 4.
The inner peripheral cam surface has a short diameter portion having a short diameter from the rotation center of the rotor, a major diameter portion having a larger diameter from the rotation center of the rotor than the minor diameter portion, and a major diameter portion from the minor diameter portion to the major diameter portion. It has a transition portion in which the diameter from the center of rotation of the rotor gradually increases toward
The maximum extrusion position at which the vane is pushed outward in the radial direction by the extrusion portion is from the boundary position that is the boundary between the transition portion and the major diameter portion in the suction region where the pump chamber expands. A vane pump characterized in that the pump chamber is set within the region up to the communication start position where the pump chamber starts communicating with the discharge port as the rotor rotates in the discharge region where the pump is contracted. In the vane pump according to claim 5.
The maximum extrusion position is set within a region from the communication end position where the communication between the pump chamber and the suction port ends with the rotation of the rotor to the communication start position of the discharge port. Vane pump. In the vane pump according to claim 5 or 6.
Further provided with a groove-shaped notch communicating with the discharge port,
The notch is formed so that the opening area gradually increases in the rotation direction of the rotor.
The vane pump is characterized in that the maximum extrusion position is set within a region from the boundary position to a position where the pump chamber starts communicating with the notch as the rotor rotates.

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