JP2009024570A - Variable displacement vane pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a variable displacement vane pump capable of introducing suction pressure to a second fluid chamber without disturbing lubrication between sliding contact surfaces of a cam ring and a pressure plate. <P>SOLUTION: A long introduction passage 40 is extended to be formed, comprising a first introduction part 41 introducing working fluid to a pressure plate 11 side, namely an axial direction end surface side far from a suction passage 16 of a cam ring 6 while detouring the cam ring 6, a first and a second fluid pressure chamber P1, P2 from the suction passage 16, and a second introduction part 42 directly opening to the second fluid pressure chamber P2 to turn to an axial direction reverse side via the pressure plate 11 from the first introduction part 41. Pump suction pressure is introduced to the second fluid pressure chamber P2 by the introduction passage 40. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an improvement in a variable displacement vane pump applied to, for example, a power steering device for a vehicle.

  For example, as a conventional variable displacement vane pump applied to a power steering device of a vehicle, for example, one described in Patent Document 1 below is known.

  This variable displacement vane pump is provided with an adapter ring fitted on the inner circumferential surface of the inner housing space of the front body formed in a substantially bottomed cylindrical shape, and is accommodated and disposed on the inner circumferential side of the adapter ring so as to be swingable. A cam ring, a rotor that is rotatably accommodated on the inner peripheral side of the cam ring, and that accommodates vanes in slots radially formed in a radial direction, and a pressure in which the rotor and the cam ring are in sliding contact with each other And an opening at one end of the accommodation space of the front body is closed by the rear body.

  The cam ring and the rotor are arranged in a state where the centers of the cam ring and the rotor are eccentric, and a plurality of pump chambers are separated by both vanes. A suction port is formed on the inner bottom surface of the front body so as to open to a region (suction region) where the volume of each pump chamber increases, and to introduce suction pressure into the pump chamber in the suction region. A discharge port is formed on the inner side surface of the discharge chamber. The discharge port opens into a region (discharge region) where the volume of each pump chamber decreases, and a discharge pressure from the discharge region is introduced.

  Further, a predetermined space is formed between the inner peripheral surface of the adapter ring and the outer peripheral surface of the cam ring, and the space is first sealed by a seal member fitted along the axial direction on the inner peripheral surface of the adapter ring. The fluid pressure chamber and the second fluid pressure chamber are separated into two pressure chambers. Further, a biasing member that biases the cam ring toward the first fluid pressure chamber is disposed on the second fluid pressure chamber side, and the cam ring is always biased toward the first fluid pressure chamber by the biasing force of the biasing member. It is energized. That is, the swing position of the cam ring is controlled based on the balance between the internal pressure of the first fluid pressure chamber, the internal pressure of the second fluid pressure chamber, and the urging force of the urging member.

  Further, the vane pump is provided with a pressure control valve for directly controlling the discharge pressure of the pump. Normally, the pump suction pressure (low pressure) is introduced into the first fluid pressure chamber by the pressure control valve. The pump discharge pressure (high pressure) is introduced only when the pump discharge pressure exceeds a predetermined value. On the other hand, an introduction passage that communicates the suction port and the second fluid pressure chamber is formed along the axial direction at a predetermined position in the circumferential direction of the pressure plate, and the second fluid passes through the introduction passage. The pump suction pressure is introduced into the pressure chamber.

  The introduction passage is formed so as to penetrate along the axial direction of the pressure plate, and has a through hole having one end opened to the suction port and the other end facing the inner surface of the cam ring, and an inner surface of the pressure plate (with respect to the cam ring). A notch formed in the opposite end surface), one end side communicating with the through hole and the other end side facing the second fluid pressure chamber, and a part of the pump suction pressure from the suction port It is introduced into the through hole and introduced into the second fluid pressure chamber through the notch groove.

  From this configuration, when the pump discharge pressure is lower than the predetermined value, the pressure control by the pressure control valve is not performed, so that the first and second fluid pressure chambers are both low pressure and are almost in equilibrium. The cam ring is held on the first fluid pressure chamber side by the biasing force of the biasing member. On the other hand, when the pump discharge pressure exceeds a predetermined value, the first fluid pressure chamber becomes high, so that the hydraulic pressure is against the low pressure of the second fluid pressure chamber and the biasing force of the biasing member. Swing control is performed on the two fluid pressure chamber side.

Therefore, this vane pump controls the swinging position of the cam ring according to the balance of the hydraulic pressure introduced into each fluid pressure chamber, and changes the discharge pressure of the pump based on the swinging position control. We are trying to save energy.
Japanese Patent Laid-Open No. 2003-74479

  However, in the conventional variable displacement vane pump, the introduction passage is provided in the vicinity of the suction port, and the introduction passage is provided facing the inner surface of the cam ring. If the rotational speed of the hydraulic oil is high and the flow speed of the hydraulic oil during suction increases, a negative pressure is generated in the introduction passage due to the flow of the hydraulic oil, and the oil stays in the vicinity of the introduction passage due to the negative pressure. Is sucked up.

  Specifically, there is a slight axial gap between the cam ring and the rotor and the pressure plate, and an oil film that lubricates sliding of the cam ring and the rotor is formed in the gap. The lubricating oil film formed on the inner surface of the cam ring facing the notch groove is sucked out of the lubricating oil film applied by the negative pressure.

  Therefore, a so-called oil film breakage occurs between the sliding surfaces of the cam ring and the pressure plate in the vicinity of the notch groove, and a sufficient lubricating action cannot be obtained at the portion where the oil film breakage occurs. Adhesive wear may occur on the inner surface.

  The present invention has been devised by paying attention to such a technical problem, and introduces suction pressure into the second fluid pressure chamber without hindering lubrication between the sliding surfaces of the cam ring and the pressure plate. The obtained variable displacement vane pump is provided.

  According to a first aspect of the present invention, there is provided a rotor that is housed and disposed in a housing space formed inside the pump body, and that is rotatably driven by a drive shaft while housing a plurality of vanes provided so as to be able to protrude and retract in a radial direction. A cam ring defining a plurality of pump chambers together with each adjacent vane and rotor, and fitted and fixed to a peripheral wall on one end side in the axial direction of the housing space, A pressure plate with which the cam ring and the rotor are in sliding contact, a first fluid pressure chamber formed on the outer circumferential side of the cam ring and on one side in the radial direction to control the eccentric amount of the cam ring, and a second fluid formed on the other side A pressure chamber, pressure control means for controlling the pressure of the hydraulic oil introduced into the first fluid pressure chamber, and the hydraulic oil formed inside the pump body and introduced from the outside to the pump chamber side. An intake passage having one end side opened in the suction passage and the other end opened in the second fluid pressure chamber. The introduction passage is connected to the inside of the cam ring from the suction passage. It extends in the shape of a long passage passing through the peripheral side or the outer peripheral side of the accommodating space, and the pump suction pressure of the suction passage is introduced into the second fluid pressure chamber through the introduction passage.

  According to the present invention, the introduction passage is extended so as to communicate with the second fluid pressure chamber at a position far away from the suction passage, so that a negative pressure phenomenon in the vicinity of the introduction passage is generated. The oil staying in the vicinity of the introduction passage, in particular, the lubricating oil film formed on the sliding surface of the cam ring is not sucked. Furthermore, since the introduction passage is directly opened to the second fluid pressure chamber, the pump suction pressure introduced into the second fluid pressure chamber does not flow on the sliding surface of the cam ring. There is no possibility that the lubricating oil film formed on the sliding surface of the cam ring is removed by the flow of pressure. As a result, the oil film on the sliding surface of the cam ring can be maintained, and the occurrence of adhesive wear due to the oil film running out of the sliding surface of the cam ring is prevented.

  Further, in particular, the introduction passage is formed to extend from the suction passage in a long shape passing through the inner peripheral side of the cam ring or the outer peripheral side of the accommodating space, and the flow path length from the suction passage to the second fluid pressure chamber By securing the length long, the pulse pressure of the pump suction pressure introduced into the second fluid pressure chamber can be attenuated. Thereby, the pump suction pressure can be introduced into the second fluid pressure chamber in a more stable state.

  According to a second aspect of the present invention, the cam ring is accommodated in an inner periphery of the adapter ring in the first aspect of the present invention, and this invention also includes the invention of the first aspect. Similar effects can be obtained.

  According to a third aspect of the present invention, there is provided a pump in which a part of the introduction passage disposed so as to pass from the suction passage to the inner peripheral side of the cam ring is located in a region where the volume of each pump chamber increases. It is characterized by comprising a room.

  According to the present invention, since a part of the introduction passage is configured using the existing configuration of the pump, the number of processing steps can be reduced as compared with the case where the entire introduction passage is newly formed.

  According to a fourth aspect of the present invention, the pressure control means is provided on a spool provided in a valve housing chamber formed inside the pump housing so as to be capable of moving forward and backward, and on one axial end side of the spool, A high-pressure chamber for introducing pressure upstream of the metering orifice provided on the downstream side of the discharge port, and a pressure on the downstream side of the metering orifice provided for the other axial end of the spool. A pressure control valve having an intermediate pressure chamber and a low pressure chamber provided at an intermediate portion in the axial direction of the spool and connected to the suction passage, and the introduction passage passes through the low pressure chamber of the pressure control valve. It is characterized by being arranged as described above.

  According to the present invention, the introduction passage is disposed so as to pass through the outer peripheral side of the accommodating space, so that the flow path length of the introduction passage is compared with the flow path layout passing through the inner peripheral side of the cam ring. Can be ensured for a long time, so that a higher pulse pressure attenuation effect can be obtained. In particular, since the introduction passage is disposed so as to pass through the low pressure chamber of the pressure control valve, it is possible to dispose the introduction passage so as to intersect with the pressure control valve, thereby increasing the size of the apparatus. Can be suppressed.

  According to a fifth aspect of the present invention, the pressure plate is disposed far away from the cam ring with respect to the suction passage, and one end side of the introduction passage passes from the suction passage to the inner peripheral side of the cam ring. The first introduction portion that opens to the axial end surface side far from the suction passage of the pressure plate and the other end side of the introduction passage opens to the first introduction portion, and the suction of the pressure plate A notch groove formed in an axial end surface far from the passage, and a second introduction portion having a through hole that opens in the notch groove and passes through the pressure plate in the axial direction. Yes.

  According to the present invention, by appropriately selecting the position of the through hole, the opening position to the second fluid pressure chamber can be freely selected, and the degree of freedom in the flow path layout of the introduction passage can be improved. I can plan.

  The invention described in claim 6 is characterized in that an orifice portion is provided in the middle of the introduction passage.

  According to the present invention, the pump suction pressure introduced into the second fluid pressure chamber can be further reduced by the damping effect of the orifice portion.

  The invention described in claim 7 is characterized in that an orifice portion is provided in the through hole.

  According to the present invention, the pump suction pressure introduced into the second fluid pressure chamber can be further reduced by the damping effect of the orifice portion.

  Embodiments of a variable displacement vane pump according to the present invention will be described below in detail with reference to the drawings. In the present embodiment, the variable displacement vane pump is applied to a vehicle power steering device as in the conventional case.

  1 to 5 show a first embodiment of the present invention. As shown in FIGS. 1 and 2, the variable displacement vane pump includes a pump body 1 formed by abutting a front body 2 and a rear body 3 with each other. An annular adapter ring 4 fitted and fixed in a housing space 10 formed inside the pump body 1, and a swinging fulcrum pin 5 in the substantially elliptical space of the adapter ring 4. A movable annular cam ring 6 and a rotor 8 that is rotatably arranged on the inner peripheral side of the cam ring 6 and connected to a drive shaft 7 that is inserted into the pump body 1 are provided.

  As shown in FIG. 2, the cam ring 6 has an axial width slightly smaller than that of the adapter ring 4 and is disposed in the accommodating space 10 in an eccentric state with respect to the rotor 8. The first fluid pressure chamber P1 and the second fluid pressure chamber P2 are separated from each other through a moving fulcrum pin 5 and a seal member 9 disposed substantially opposite to the pin.

  As shown in FIG. 1, the rotor 8 is formed in a substantially disc shape and has substantially the same axial width as the cam ring 6, and both axial sides of the rotor 8 together with the cam ring 6 are located in the rear body 3 and the accommodating space 10. The disc-shaped pressure plate 11 made of a sintered material arranged on the bottom 2a side of the front body 2 is arranged in a sandwiched state via a slight axial gap C.

  The rotor 8 rotates in the direction of the arrow in FIG. 2 (counterclockwise) when the drive shaft 7 is rotationally driven by an engine (not shown). A plurality of slots 8a along the radial direction are formed at the interval positions. In each slot 8a, a plurality of vanes 12 are held so as to be able to protrude and retract radially in the direction of the inner peripheral surface of the cam ring 6, respectively. In addition, a substantially circular back pressure chamber 8b is provided continuously and integrally at the inner peripheral end of each slot 8a.

  A plurality of pump chambers 13 are defined by two adjacent vanes 12 in a space formed between the cam ring 6 and the rotor 8, and the cam ring 6 is connected to the swing fulcrum pin 5. By swinging as a fulcrum, the volume of each pump chamber 13 is increased or decreased.

  A compression coil spring 14 is disposed in the second fluid pressure chamber P2. The compression coil spring 14 causes the cam ring 6 to move toward the first fluid pressure chamber P1, that is, in a direction in which the volume of the pump chamber 13 is maximized. Always energized.

  As shown in FIGS. 1 and 2, the inner surface 3 a on the rotor 8 side of the rear body 3 in the suction area A where the volume of the pump chamber 13 gradually expands as the rotor 8 rotates is substantially arc-shaped. One suction port 15 is formed in a notch. The first suction port 15 has a first suction hole 15a formed in the central portion thereof, which opens to a suction passage 16 formed in the rear body 3, and passes through a suction pipe 17 connected to a reservoir tank (not shown). Then, the hydraulic oil introduced into the suction passage 16 is supplied to each pump chamber 13 through the first suction hole 15a.

  Further, a concave portion 3b that pivotally supports one end portion of the drive shaft 7 is formed at a substantially central position of the inner side surface 3a of the rear body 3, and communicated with the suction passage 16 on the bottom side of the concave portion 3b. A reflux passage 18 is formed. The recirculation passage 18 leaks hydraulic oil that has leaked from the axial gap C between the inner surface 3a of the rear body 3 and the outer surface 8c of the rotor 8 on the rear body 3 side and flows into the recess 3b to the suction passage 16. The refrigerant is refluxed and introduced again into the first suction port 15 through the first suction hole 15a.

  On the other hand, as shown in FIGS. 1 to 5, the inner surface 11 a on the rotor 8 side of the pressure plate 11 in the discharge region B in which the volume of each pump chamber 13 is gradually reduced with the rotation of the rotor 8, An arc-shaped first discharge port 19 and a plurality of discharge holes 20 communicating therewith are formed. Then, the hydraulic oil discharged from the pump chamber 13 is introduced into the pressure chamber 21 formed in the bottom 2a of the front body 2 through the first discharge port 19 and the discharge holes 20, and further, the pump body By being discharged through a discharge passage (not shown) formed in 1, it is sent to a hydraulic power cylinder of a power steering device (not shown).

  Further, a second suction port 22 having substantially the same shape as the first suction port 15 is cut out at a position facing the first suction port 15 on the inner side surface 11 a of the pressure plate 11. The second suction port 22 is formed with a second suction hole 22a penetratingly formed in the center of the second suction port 22, which opens into a relief passage 23 formed in the front body 2. The hydraulic oil recirculated through the relief passage 23 is supplied to each pump chamber 13 on the suction side through the second suction hole 22a.

  On the other hand, at the position facing the first discharge port 19 on the inner side surface 3a of the rear body 3, a second discharge port 24 having substantially the same shape as the first discharge port 19 is cut out as shown in FIG. Yes.

  As described above, the first and second suction ports 15 and 22 and the first and second discharge ports 19 and 24 are substantially symmetrical in the axial direction on the inner side surfaces 3a and 11a of the rear body 3 and the pressure plate 11, respectively. By providing, the pressure balance of the axial direction both sides of each said pump chamber 13 is maintained.

  A through hole 26 through which the drive shaft 7 is inserted is formed at the center position of the pressure plate 11, and a shaft hole 2b that supports the other end side of the drive shaft 7 is formed in the bottom 2a of the front body. Is formed so as to be coaxial with the through-hole 26 along the axial direction. Both the through hole 26 and the shaft hole 2 b are set to have an inner diameter slightly larger than the outer diameter of the drive shaft 7, and the inner peripheral surface of the through hole 26 and the shaft hole 2 b and the outer peripheral surface of the drive shaft 7 are set. A cylindrical oil passage 27 into which hydraulic oil leaked from the axial gap C between the inner side surface 11a of the pressure plate 11 and the inner side surface 8d of the rotor 8 flows is formed therebetween.

  Further, a seal member 28 having an annular groove 28a on the inner surface is disposed at a substantially central position in the axial direction of the shaft hole 2b, and a gap between the inner peripheral surface of the shaft hole 2b and the outer peripheral surface of the drive shaft 7 is provided. It is sealed. The bottom portion 2a of the front body 2 is formed so that one end side is adjacent to the annular groove 28a of the seal member 28 and the other end side is connected to the relief passage 23 so as to be substantially parallel to the shaft hole 2b. As a result, the hydraulic oil flowing into the cylindrical oil passage 27 is returned to the relief passage 23 through the annular groove 28a and introduced again into the second suction port 22 through the second suction hole 22a. ing.

  Further, a pressure control valve 30 for controlling the discharge pressure of the pump is provided in the direction perpendicular to the drive shaft 7 inside the upper end side of the front body 2. As shown in FIG. 2, the pressure control valve 30 includes a spool valve 32 slidably received in a valve hole 31 formed in the front body 2, and the spool valve 32 attached to the left in the figure. A valve spring 34 that is brought into contact with the plug 33 of the valve hole 31 and a hydraulic pressure upstream of the metering orifice (not shown), that is, the pressure, is formed between the plug 33 and the tip of the spool valve 32. A high pressure chamber 35 into which hydraulic oil in the chamber 21 is introduced, and an intermediate pressure chamber 36 that accommodates the valve spring 34 and into which the oil pressure downstream of the metering orifice is introduced. When the pressure difference between the chamber 36 and the high pressure chamber 35 exceeds a predetermined value, the spool valve 32 moves to the right in the figure against the spring force of the valve spring 34.

  When the spool valve 32 is located on the left side in FIG. 2, the first fluid pressure chamber P <b> 1 is connected to the outer periphery of the spool valve 32 via a communication passage 38 that communicates the first fluid pressure chamber P <b> 1 and the valve hole 31. It is connected to a low pressure chamber 37 defined on the side. As shown in FIG. 1, a low pressure from the suction passage 16 is introduced into the low pressure chamber 37 via a low pressure passage 39 formed by branching from the suction passage 16.

  When the spool valve 32 slides to the right in FIG. 2 due to the pressure difference between the chambers 35 and 36, the low-pressure chamber 37 is gradually shut off and communicates with the high-pressure chamber 35 to provide a high-pressure hydraulic oil. Will be introduced. That is, the hydraulic pressure of the low pressure chamber 37 and the hydraulic pressure upstream of the metering orifice are selectively supplied into the first fluid pressure chamber P1.

  The relief valve 50 disposed in the spool valve 32 is provided when the pressure in the intermediate pressure chamber 36 reaches a predetermined level or higher, that is, when the pressure in the hydraulic power cylinder reaches a predetermined level or higher. The hydraulic oil is released to escape to the relief passage 23.

  On the other hand, as shown in FIG. 1, the second fluid pressure chamber P2 bypasses the cam ring 6 and the first and second fluid pressure chambers P1 and P2 from the suction passage 16 to the pressure plate 11 side. The intake side hydraulic pressure (low pressure) is always introduced by the introduction passage 40 that is disposed in the opening passage and opens directly to the second fluid pressure chamber P2 via the pressure plate 11.

  The introduction passage 40 is constituted by the first suction hole 15a, the pump chamber 13 and the second suction hole 22a in the suction region A, and passes through the inner peripheral side of the cam ring 6 so that the cam ring 6 and both fluid pressure chambers P1, The first introduction part 41 extended so as to bypass P2, and the pressure plate 11 are formed on the pressure plate 11, and the pressure plate 11 side is folded from the terminal part of the first introduction part 41 to the opposite side in the axial direction, that is, The cam ring 6 includes a second introduction portion 42 that opens to the second fluid pressure chamber P2 from the axial end surface side far from the suction passage 16.

  The second introduction portion 42 is formed through the pressure plate 11 substantially along the axial direction, and is a small-diameter hole that is a through-hole that directly opens into the second fluid pressure chamber P2 at one end side and forms an extremely small-diameter orifice portion. 43 and a communication groove 44 which is a notch formed in a predetermined range of the outer surface 11b of the pressure plate 11 and is a notch groove for communicating the small diameter hole 43 and the second suction hole 22a.

  As shown in FIGS. 1, 3, and 4, the small-diameter hole 43 is provided in the vicinity of the outer peripheral side of the second suction hole 22a and at a predetermined position that directly opens to the second fluid pressure chamber P2. And provided so as to be slightly inclined toward the center from one end side toward the other end side.

  As shown in FIG. 5, the communication groove 44 is formed in a substantially arc shape along the circumferential direction in a predetermined range near the second suction hole 22 a, and is formed in the second suction hole 22 a and the small diameter hole 43 in the radial direction. It is provided to straddle. At this time, the communication groove 44 is set in a range that completely overlaps the small-diameter hole 43, and the other end portion of the small-diameter hole 43 opens at the bottom of the communication groove 44. ing.

  Further, as shown in FIGS. 3 and 4, the inner surface 11 a of the pressure plate 11 is substantially circular having a predetermined circumferential length at a position facing the back pressure chambers 8 b in the suction area A. An arcuate suction side back pressure groove 45 is cut out. The suction-side back pressure groove 45 has communication holes 45a communicating with the pressure chambers 21 at both ends thereof, and a part of the hydraulic oil in the pressure chambers 21 is passed through the communication holes 45a. The pressure chamber 8b is supplied.

  On the other hand, also in the discharge region B of the inner side surface 11a, a discharge side back pressure groove 46 having substantially the same shape as the suction side back pressure groove 45 is provided at the position facing each back pressure chamber 8b. A notch is formed on the same circumference as the suction-side back pressure groove 45 so as to be substantially symmetric with respect to 45 (vertical symmetry in FIG. 3). The discharge-side back pressure groove 46 is also provided with a throttle hole 46a communicating with the pressure chamber 21 along the axial direction, and a part of the hydraulic oil in the pressure chamber 21 is supplied to each back pressure through the throttle hole 46a. It supplies to the chamber 8b.

  As shown in FIG. 3, an annular lubricating groove is provided between the suction side back pressure groove 45, the discharge side back pressure groove 46 and the through hole 26 in the radial direction on the inner surface 11 a of the pressure plate 11. 47 is formed with a notch, and the sliding contact between the rotor 8 and the pressure plate 11 is effectively lubricated by the lubricating groove 47.

  Further, as shown in FIG. 1, an annular seal holding groove is formed in the inner surface of the bottom 2a of the front body 2, and a seal member 48 made of a rubber material is fitted and held in the seal holding groove. Has been. The seal member 48 is formed on the outer surface 11b of the pressure plate 11 so that the inside and outside of the outer peripheral area of the second suction hole 22a are divided into a low pressure area communicating with the suction side and a high pressure area communicating with the discharge side. The oil pressure (low pressure) introduced from the relief passage 23 is applied to the inner low pressure region surrounded by the member 48, while the oil pressure introduced from the pressure chamber 21 to the high pressure region outside the seal member 48. (High pressure) is applied.

  From the above configuration, in the variable displacement vane pump, the pressure plate 11 presses the adapter ring 4, the cam ring 6, and the entire rotor 8 toward the rear body 3 side by the hydraulic pressure acting on the outer surface 11b, The axial gaps C between the pressure plate 11 and the rear body, the adapter ring 4, the cam ring 6, and the rotor 8 are reduced, and the leakage of hydraulic oil in the pump chambers 13 due to the axial gaps C is reduced as much as possible. .

  Then, by reducing the axial gaps C in this way, the pressure plate 11 and the rear body 3 come into sliding contact with the cam ring 6 and the rotor 8, so that the shafts of the pressure plate 11, the cam ring 6 and the rotor 8 are arranged. Between the directions and between the rear body 3 and the cam ring 6 and the rotor 8 in the axial direction, a lubricating oil film is formed through the slight axial gaps C, and this lubricating oil film suppresses wear of each component due to the sliding contact. Has been.

  Here, in the variable displacement vane pump, when the suction side hydraulic pressure (low pressure), which is the suction pressure of the pump, is introduced into the second fluid pressure chamber P2, the suction passage 16 passes through the first suction hole 15a. Then, part of the hydraulic oil introduced into the pump chamber 13 in the suction area A is guided to the communication groove 44 through the second suction hole 22a, and the second fluid is passed through the small diameter hole 43 from the communication groove 44. It is set as the structure introduce | transduced into the pressure chamber P2.

  Therefore, according to this embodiment, the introduction passage 40 is extended so as to communicate with the second fluid pressure chamber P2 at a position far away from the suction passage 16, so that the conventional introduction passage 40 in the vicinity of the introduction passage 40 is provided. The occurrence of such a negative pressure phenomenon can be prevented, and there is no possibility that the hydraulic oil staying in the vicinity of the introduction passage 40, in this case, the lubricating oil film formed on the inner surface of the cam ring 6 will be sucked.

  Furthermore, the introduction passage 40 is configured to open directly to the second fluid pressure chamber P2, so that the suction-side hydraulic pressure introduced into the second fluid pressure chamber P2 flows on the sliding surface of the cam ring 6. Therefore, there is no possibility that the lubricating oil film formed on the sliding surface of the cam ring 6 is removed when the suction side hydraulic pressure flows through the introduction passage 40.

  As a result, the oil film on the sliding surface of the cam ring 6 can be reliably maintained, and adhesion wear due to the oil film running off on the sliding surface of the cam ring 6 can be prevented. As a result, a favorable swinging action of the cam ring can be obtained.

  In particular, the introduction passage 40 is extended from the suction passage 16 so as to pass through the inner peripheral side of the cam ring 6, and a long passage length from the suction passage 16 to the second fluid pressure chamber P2 is secured. As a result, it is possible to attenuate the pulse pressure of the suction-side hydraulic pressure introduced into the second fluid pressure chamber P2. Further, by adopting a configuration in which the small-diameter hole 43 is provided at the end portion of the introduction passage 40, further static pressure of the hydraulic pressure introduced into the second fluid pressure chamber P2 by the damping effect of the small-diameter hole 43. Can be achieved.

  As a result, there is no possibility that the second fluid pressure chamber P2 is affected by pulsation or cavitation that occurs in the suction side oil pressure especially during high pump rotation, and a more stable oil pressure can be introduced into the second fluid pressure chamber P2. .

  In addition, since the first introduction part 41 is configured using the existing configuration of the pump such as the first suction hole 15a, the pump chamber 13 in the suction region A, and the second suction hole 22a, the first introduction part 41 is provided. Compared with the case where the portion 41 is separately provided, the number of processing steps can be reduced, and thereby the manufacturing cost can be prevented from rising.

  In addition, the second introduction portion 42 is configured by the small-diameter hole 43 that penetrates the inside of the pressure plate 11 in the axial direction and the communication groove 44 that is formed in the outer surface 11b of the pressure plate 11. The position of the opening to the second fluid pressure chamber P2 can be freely selected by appropriately selecting the position of the small diameter hole 43. Thereby, the freedom degree of the flow path layout of the second introduction part 42 can be improved.

  6 to 10 show a second embodiment of the present invention. The basic configuration is the same as that of the first embodiment. The difference is that the communication groove 44 is eliminated and the small diameter hole 43 is removed. The other end side of the small-diameter hole 43 is relieved by setting the inclination of the pressure plate 11 toward the center of the pressure plate 11 and extending the length of the relief passage 23 opening in the second suction hole 22a in the radial direction of the front body 2 The second introduction portion 42 is configured by the relief passage 23 and the small diameter hole 43 so as to open directly into the passage 23.

  Further, the small-diameter hole 43 is set so that the opening position on one end side thereof is slightly shifted along the circumferential direction of the pressure plate 11 to the opposite side of the rotation direction of the pump, as shown in FIG. One end side opens at a position having a larger radial width in the second fluid pressure chamber P2.

  Therefore, according to this embodiment, the same effect as the first embodiment can be obtained, and a part of the second introduction part 42 is an existing configuration of the pump. Since the relief passage 23 is used, the introduction passage 40 can be formed only by penetrating the small-diameter hole 43 in the pressure plate 11. In this case, since the introduction passage 40 can be easily formed only by drilling the pressure plate 11, the number of processing steps required for forming the introduction passage 40 can be further reduced. As a result, it is possible to further suppress an increase in manufacturing cost accompanying the formation of the introduction passage 40.

  Furthermore, by opening one end side of the small diameter hole 43 at a position having a larger radial width in the second fluid pressure chamber P2, it is possible to introduce more hydraulic oil into the second fluid pressure chamber P2. At the same time, the length of the small-diameter hole 43 can be secured longer. As a result, the damping effect by the small-diameter hole 43 can be improved without reducing the hydraulic oil introduction efficiency.

  11 to 14 show a third embodiment of the present invention, the basic configuration is the same as that of the first embodiment, and the layout (configuration) of the introduction passage 40 is changed. . In the description of the present embodiment, for the sake of convenience, members and parts similar to those in the first embodiment will be described with the same names and symbols as those in the first embodiment.

  That is, in the variable displacement vane pump according to this embodiment, as shown in FIGS. 11 and 12, the low pressure chamber 37 of the pressure control valve 30 is provided on the inner wall 11 a of the pressure plate 11 on the peripheral wall of the housing space 10. A small-diameter hole 51 that is an extremely fine through-hole facing the outer peripheral surface of the axial end portion on the side is formed.

  Further, as shown in FIGS. 11 to 14, a communication groove 52 having a substantially rectangular cross section is provided at a predetermined position in the circumferential direction on the outer peripheral edge of the pressure plate 11 on the inner side surface 11 a side of the pressure plate 11. A notch is formed along the radial direction from the outer peripheral edge of the plate 11. The communication groove 52 is formed so that its radial width D is slightly larger than the radial width d of the opposing adapter ring 4, and allows the small-diameter hole 51 and the second fluid pressure chamber P2 to communicate with each other.

  As shown in FIG. 11, the introduction passage 40 is configured such that the first introduction portion 41 bypasses the cam ring 6 and the first and second fluid pressure chambers P <b> 1 and P <b> 2 through the outer peripheral side of the accommodation space 10. The second fluid pressure chamber P2 extends from the axial end surface side far from the suction passage 16 of the cam ring 6 so as to be folded back to the opposite side in the axial direction via a second introduction portion 42 formed in the pressure plate 11. It is provided so as to open.

  That is, the first introduction portion 41 includes the low pressure passage 39 that opens to the suction passage 16, the low pressure chamber 37 of the pressure control valve 30 that communicates with the suction passage 16 through the low pressure passage 39, and the low pressure passage 39. The second introduction portion 42 is constituted by a communication groove 52 that allows the small diameter hole 51 and the second fluid pressure chamber P2 to communicate with each other.

  Therefore, according to this embodiment, the same effect as that of the first embodiment can be obtained, and the introduction passage 40 is arranged so as to pass through the outer peripheral side of the accommodation space 10. Since it is provided, it is possible to ensure a longer flow path length of the introduction passage 40 than a flow path layout passing through the inner peripheral side of the cam ring 6 as in the first embodiment. As a result, the pulse pressure attenuation effect by the introduction passage 40 can be further improved.

  Furthermore, since the first introduction part 41 is disposed so as to pass through the low pressure chamber 37 of the pressure control valve 30, the first introduction part 41 and the pressure control valve 30 may be disposed so as to cross each other. Since it becomes possible, the enlargement of the pump apparatus accompanying formation of this introduction channel | path 40 can be suppressed.

  Moreover, since the first introduction part can be formed only by additionally processing the small-diameter hole 51 in the front body 2, it is possible to contribute to the suppression of the increase in manufacturing cost associated with the arrangement of the introduction passage 40.

  On the other hand, the second introduction portion 42 can also be formed by notching the outer peripheral edge portion of the inner side surface 11a of the pressure plate 11 from the outer peripheral side of the pressure plate 11, so that the introduction passage 40 is disposed. The accompanying increase in manufacturing cost can be suppressed.

  The present invention is not limited to the configuration of each of the above embodiments, and the layout and length of the introduction passage 40 can be freely changed according to the specifications and size of the pump device.

  That is, the introduction passage 40 is formed in a long shape that bypasses the cam ring 6 and the first and second fluid pressure chambers P1 and P2 through the inner peripheral side of the cam ring 6 and the outer peripheral side of the accommodating space 10. As long as it is provided so as to directly open to the second fluid pressure chamber P2 without passing through the axial end surface of the cam ring 6, the main effects of the present invention can be obtained regardless of the flow path layout. Can play.

  Further, in the third embodiment, a through hole that faces the outer peripheral surface of the adapter ring 4 from the low pressure chamber 37 of the pressure control valve 30 is formed in the peripheral wall of the accommodation space 10, and the through hole and the second hole The introduction passage 40 may be configured by forming an extremely small small-diameter hole communicating with the fluid pressure chamber P2 in the adapter ring 4 along the radial direction. In this case, the through-hole and the small-diameter hole are either Since it can be formed only by drilling, it is possible to contribute to a reduction in the number of processing steps required for forming the introduction passage 40.

BRIEF DESCRIPTION OF THE DRAWINGS It is axial sectional drawing of the pump which shows 1st Embodiment of the variable displacement vane pump which concerns on this invention, and demonstrates the principal part of this invention. It is the sectional view on the AA line of FIG. It is a front view of the pressure plate of the variable displacement vane pump showing the embodiment. FIG. 4 is a sectional view taken along line BB in FIG. 3. It is a rear view of the pressure plate of the variable displacement vane pump showing the embodiment. FIG. 5 is a sectional view in the axial direction of a pump illustrating a second embodiment of a variable displacement vane pump according to the present invention and explaining a main part of the present invention. It is CC sectional view taken on the line of FIG. It is a front view of the pressure plate of the variable displacement vane pump showing the embodiment. It is the DD sectional view taken on the line of FIG. It is a rear view of the pressure plate of the variable displacement vane pump showing the embodiment. FIG. 5 is a sectional view in the axial direction of a pump illustrating a third embodiment of a variable displacement vane pump according to the present invention and explaining a main part of the present invention. It is the EE sectional view taken on the line of FIG. It is a front view of the pressure plate of the variable displacement vane pump showing the embodiment. It is the FF sectional view taken on the line of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Pump body 6 ... Cam ring 7 ... Drive shaft 8 ... Rotor 9 ... Sealing member 10 ... Accommodating space 11 ... Pressure plate 12 ... Vane 13 ... Pump chamber 16 ... Suction passage 30 ... Pressure control means (pressure control valve)
40 ... Introduction passage P1 ... First oil pressure chamber P2 ... Second oil pressure chamber

Claims (7)

A rotor that is housed in a housing space formed inside the pump body, and that is driven to rotate by a drive shaft while housing a plurality of vanes provided so as to be able to protrude and retract in a radial direction;
A cam ring that is swingably provided on the outer peripheral side of the rotor, and that defines a plurality of pump chambers together with the adjacent vanes and the rotor;
A pressure plate that is fitted and fixed to a peripheral wall on one end side in the axial direction of the housing space, and the cam ring and the rotor are in sliding contact with each other;
A first fluid pressure chamber formed on the outer peripheral side of the cam ring and on one side in the radial direction to control the eccentric amount of the cam ring, and a second fluid pressure chamber formed on the other side;
Pressure control means for controlling the pressure of hydraulic oil introduced into the first fluid pressure chamber;
A suction passage that is formed inside the pump body and guides hydraulic oil introduced from the outside to the pump chamber side, and
An inlet passage having an opening formed in the suction passage on one end side and an opening formed in the second fluid pressure chamber on the other end side;
The introduction passage is formed to extend from the suction passage in a long shape passing through the inner peripheral side of the cam ring or the outer peripheral side of the accommodating space,
A variable displacement vane pump, wherein a pump suction pressure of the suction passage is introduced into the second fluid pressure chamber through the introduction passage. A rotor that is housed in a housing space formed inside the pump body, and that is driven to rotate by a drive shaft while housing a plurality of vanes provided so as to be able to protrude and retract in a radial direction;
A cam ring that is swingably provided on the outer peripheral side of the rotor, and that defines a plurality of pump chambers together with the adjacent vanes and the rotor;
An adapter ring that is fitted and fixed to the peripheral wall of the housing space, and supports the cam ring in a swingable manner on the inner peripheral side;
A pressure plate that is fitted and fixed to a peripheral wall on one axial end side of the housing space, and the cam ring and the rotor are in sliding contact with each other;
A first fluid pressure chamber provided between the cam ring and the adapter ring, formed on one side in the radial direction of the cam ring to control the eccentric amount of the cam ring, and a second fluid pressure chamber formed on the other side; ,
Pressure control means for controlling the pressure of hydraulic oil introduced into the first fluid pressure chamber;
A suction passage that is formed inside the pump body and guides hydraulic oil introduced from the outside to the pump chamber side, and
One end side is provided with an opening formed in the suction passage, and the other end side is provided with an introduction passage formed in the second fluid pressure chamber.
The introduction passage is formed so as to extend from the suction passage into a long shape passing through the inner peripheral side of the cam ring or the outer peripheral side of the adapter ring,
A variable displacement vane pump, wherein a pump suction pressure of the suction passage is introduced into the second fluid pressure chamber through the introduction passage. A part of the introduction passage arranged so as to pass from the suction passage to the inner peripheral side of the cam ring is constituted by a pump chamber located in a region where the volume of each pump chamber increases. The variable displacement vane pump according to claim 1 or 2. The pressure control means, a spool provided in a valve housing chamber formed inside the pump housing so as to be movable back and forth;
A high-pressure chamber that is provided at one end of the spool in the axial direction and into which a pressure upstream of a metering orifice provided downstream of the discharge port is introduced;
An intermediate pressure chamber provided on the other axial end side of the spool, into which pressure downstream of the metering orifice is introduced;
A pressure control valve provided at an intermediate portion in the axial direction of the spool and having a low pressure chamber connected to the suction passage;
The variable displacement vane pump according to claim 1 or 2, wherein the introduction passage is disposed so as to pass through a low pressure chamber of the pressure control valve. The pressure plate is disposed farther away from the cam ring than the suction passage;
One end side of the introduction passage is constituted by a first introduction portion that opens from the suction passage through the inner peripheral side of the cam ring to the axial end surface side far from the suction passage of the pressure plate,
The other end side of the introduction passage is opened to the first introduction portion, a notch groove formed in an axial end surface far from the suction passage of the pressure plate, an opening in the notch groove, and the pressure plate 3. The variable displacement vane pump according to claim 1, wherein the variable displacement vane pump is configured by a second introduction portion having a through hole penetrating the inside in an axial direction. The variable displacement vane pump according to claim 1 or 2, wherein an orifice portion is provided in the middle of the introduction passage. 6. The variable displacement vane pump according to claim 5, wherein an orifice is provided in the through hole.

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