WO2005003564A1

WO2005003564A1 - Vane pump

Info

Publication number: WO2005003564A1
Application number: PCT/JP2003/008620
Authority: WO
Inventors: Shigeji Kunimoto; Mitsuhiro Aota
Original assignee: Unisia Jkc Steering Systems Co., Ltd.
Priority date: 2003-07-07
Filing date: 2003-07-07
Publication date: 2005-01-13
Also published as: JP4484817B2; JPWO2005003564A1; CN1764785A

Abstract

A vane pump, comprising a vane rotor (9) rotatably stored in a cam ring and vanes (16) held so as to be projected from and recessed into a plurality of slots (15) radially formed in the outer peripheral part of the vane rotor, wherein slot formed parts (17) projectedly formed on the outer peripheral part of the vane rotor are formed of first portions (17a) on the rotating direction side of the vane rotor and second portions (17b) on the opposite side of the rotating direction side, the chamfered parts (42) of the vane rotor on the slot formed part sides are formed only at the outer edges thereof along both profiles of the first and second portions, and both outside faces of the first and second portions are formed in projected shapes with the same height as the side faces of the vane rotor on the inner peripheral sides of the chamfered parts, whereby a sealing performance can be provided by changing chamfered part forming positions on the slot formed parts of the vane rotor.

Description

Description Vane pump Technical field

The present invention relates to a vane pump used for a hydraulic power source of a power steering of a vehicle. Background art

Various types of conventional vane pumps used in this type of vehicle have been conventionally provided, and one of them is described in Japanese Patent Application Laid-Open No. Hei 9-134274 published by the Japan Patent Office. Are known.

In this vane pump, a cam ring is housed inside a pump housing, and a vane rotor that forms a pressure and a chamber between an outer peripheral surface and an inner peripheral surface of the cam ring is rotatably provided in the cam ring. ing.

In addition, a plurality of slots are formed in the outer peripheral portion of the vane rotor at substantially equal circumferential positions along the radial direction, and a thin plate vane is formed inside each slot. The cam ring is held so as to be able to protrude and retract in the direction of the inner peripheral surface. The opening is connected to a drive shaft inserted into the pump housing. Rotational force is transmitted to the drive shaft from the crankshaft of the engine by an evening belt via a driven pulley attached to the outer end side. Then, when the vane opening is rotated with the rotation of the drive shaft, each vane protrudes from the slot due to the pressure of the back pressure chamber, and the tip end of each vane contacts the inner peripheral surface of the cam ring. It rotates while sliding. This allows the hydraulic pressure flowing into the pump chamber between the vanes from the suction port formed in the pump housing to be discharged to the discharge port while being compressed by the vanes, thereby performing the pumping action. It has become. By the way, in the conventional vane pump, recently, as shown in FIGS. 7 and 8, other than the slot forming portion 52 in which the respective slots 51 on the outer peripheral portion of the rotor 50 are formed. Lightening portions 53 are formed intermittently on the outer peripheral surface to satisfy the demand for cost reduction by reducing the material of the rotor 50 formed of, for example, a sintered alloy. , 57, the pump pulsation reduction effect can be exhibited by increasing the pump volume.

Further, in this vane pump, a stepped concave chamfered portion 54 is formed on an outer edge of an outer peripheral portion of the mouthpiece 50. The chamfered portion 54 is formed in order to prevent so-called burrs from being generated between the die and the mold when the die 50 is sintered and formed. In the evening 50, both sides of the outer peripheral side are fixed in the circumferential direction, that is, both outer edge portions 54a near the lightening portion 53 and both side portions 54b of the slot forming portion 52 are formed. It is formed over the whole.

For this reason, when the mouth 50 rotates, the inner surfaces 55 5 a facing the left and right side plates 55, 56 slidingly in contact with the side surfaces 50 a, 50 b respectively of the roller 50. The gaps C and C are formed due to the presence of the chamfered portions 54b and 54b between the groove forming portions 56a and the side surfaces of the slot forming portion 51.

For this reason, the sealing performance between the opposing surfaces of the side plates 55, 56 and the both side edges of the vane 57 is reduced, and the hydraulic oil flows through the clearances C, C near the discharge port where the pressure is highest. Leakage to the low pressure side through the pump, which may result in a decrease in pump efficiency. Disclosure of the invention

The present invention has been devised in view of the conventional technical problem, and the invention according to claim 1 has, in particular, a configuration in which a convexly formed slot forming portion is formed around a slot. A first portion on the rotation direction side and a second portion on the opposite side to the rotation direction, and the chamfered portion on the slot forming portion side has a small number of the first and second portions. At least one of the outer edges along the contour on one side, and the outer surface of either the first part or the second part is the same height as the rotor side surface on the inner peripheral side of the chamfer. It is characterized by being formed in a shape.

According to the present invention, the position where the chamfered portion formed in the slot forming portion is formed is limited, and the chamfered portion is formed only on the outer peripheral edge of at least one of the first and second portions. Since the side surface is convex, the convex outer surface sufficiently exerts a sealing function. Therefore, it is possible to sufficiently prevent leakage of hydraulic oil from the side surface between the inner surface of the side plate and the vane. As a result, a decrease in pump efficiency can be prevented.

The invention according to claim 2 is characterized in that the chamfered portion on the slot forming portion side is formed only on an outer edge along the contour of the first portion, and the outer surface of the first portion is formed in a convex shape. It is characterized by.

According to the present invention, the first portion side (high-pressure side) located in the rotor rotation direction from the vane has a convex outer surface, so that the sealing function is effectively exerted and leakage is effectively prevented. it can.

The invention according to claim 3 is characterized in that the chamfered portion on the slot forming portion side is formed only on the outer edge along the contour of the second portion, and the outer surface of the second portion is formed in a convex shape.徵.

In the present invention, since the outer surface on the second portion side is convex, the sealing performance is slightly reduced as compared with the first portion side, but the sealing performance is sufficiently improved as compared with the conventional case. .

In addition, since the second portion side is made convex, the rigidity is increased, so that the support rigidity of the vane is increased. In other words, the hydraulic pressure becomes highest on the first part side near the discharge port, and this high pressure is received on the side of the vane on the first part side, and this reaction force is transmitted to the second part. Has high rigidity, which increases the support rigidity of the vane, provides stable support, and improves the durability of the slot forming section The

The invention according to claim 4, wherein the chamfered portion on the slot forming portion side is formed on an outer side along both contours of the first portion and the second portion, and an outer surface of the first portion and the second portion. Is characterized by being formed in a convex shape.

According to the present invention, since both the outer surfaces (the outer surfaces excluding the chamfered portions) of the first and second portions are convex, it is possible to satisfy both the high sealing performance and the high rigidity. Will be possible. Brief Description of Drawings

FIG. 1 is a longitudinal sectional view showing a vane pump according to a first embodiment of the present invention. FIG. 2 is a sectional view taken along line AA of FIG. 1 of FIG.

FIG. 3 is a front view of the vane rotor and the cam ring provided in the present embodiment. FIG. 4 is a sectional view taken along line BB of FIG.

FIG. 5 is an enlarged view of a portion C in FIG.

FIG. 6 is a sectional view taken along line DD of FIG.

FIG. 7 is an enlarged view of a main part of a conventional vane pump.

FIG. 8 is a sectional view taken along line EE of FIG. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of a vane pump according to the present invention will be described in detail with reference to the drawings. This vane pump is applied to a pump as a supply source for supplying hydraulic pressure to hydraulic equipment such as a vehicle power steering device, and is fixed to a cylinder block of an internal combustion engine by bolts as shown in Fig. 1. A pump housing 1, a pump main body 2 disposed in the pump housing 1, and a drive shaft 3 having one end portion communicating with the inside of the pump housing 1.

As shown in FIGS. 1 and 2, the pump housing 1 has a suction passage 4 and a discharge passage. A pump body 6 having a block 5 having a passage 5 and a pump power par 7 connected to the pump body 6. A space for accommodating the pump body 2 between the pump body 6 and the pump power par 7. Is provided.

The pump body 2 includes, as shown in FIGS. 1 to 4, a cam ring 8 housed and arranged inside the pump cover 7, a vane rotor 9 rotatably provided inside the cam ring 8, A pair of side plates 10 and 11 are provided on both sides of the cam ring 8.

As shown in FIG. 3, the cam ring 8 is provided with a pair of small semicircular pin receiving grooves 8b and 8c formed at approximately 180 ° positions on the outer peripheral surface thereof. Thus, the pump housing 1 is positioned in the circumferential direction, and the inner peripheral surface 8a is formed in an almost elliptical shape.

The vane rotor 9 is integrally formed in a substantially disk shape by a sintered alloy, and forms a substantially annular pump chamber 14 between the outer peripheral surface and the inner peripheral surface 8a of the cam ring 8. . A serration hole 9b through which the one end 3a of the drive shaft 3 penetrates through the side plates 10 and 11 and which is serrated and formed is formed in the center of the vane pan 9 and an outer peripheral portion. In this case, ten slots 15 are radially formed at equally spaced positions in the circumferential direction. Each of the slots 15 holds a thin plate-shaped vane 16 therein so as to be slidable in the radial direction, and the bottom has a direction in which each vane 16 protrudes, a tip 1 A back pressure chamber 15a is formed so that 6a protrudes from the open end 15a of the slot 15 in the direction of the inner peripheral surface 8a of the cam ring 8. Further, as shown in FIGS. 3 to 5, the vane rotor 9 has an arc-shaped hollow portion which is a cutout at a portion other than the slot forming portion 17 where the respective slots 15 are formed on the outer peripheral surface. 18 are formed.

As shown in FIG. 3, FIG. 5, and FIG. 6, each of the slot forming portions 17 is formed in a convex shape due to the presence of each of the lightening portions 18, and has a substantially center in the circumferential direction. The slot 15 is formed at the position, and a ventilator centered on the slot 15 A first portion 17a on the rotation direction side of the motor 9 and a second portion 17b on the opposite side to the rotation direction, each circle of the first portion 17a and the second portion 17b. The circumferential lengths L 3 and L 4 are substantially the same.

Further, in the vane roaster 9, an arc-shaped first chamfered portion 17 c is formed at each outer end edge of the slot forming portion 17 on the vane rotor rotation direction (the direction of the arrow) and on the opposite side to the rotation direction. In addition, an arc-shaped second chamfered portion 17 d is formed between the base portion of the slot forming portion 17 and the connecting portion of the lightened portion 18, and the second chamfered portion 17 d is formed. The radius of curvature R of d is set to be larger than the radius of curvature of the first chamfer 17c.

Further, the vane rotor 9 is formed on the outer peripheral edge of both sides of the slot forming portion 17 and the lightening portion 18 on the outer peripheral portion in order to prevent burrs which are easily generated when the vane rotor 9 is sintered and formed. A substantially circular third chamfered portion 40 is formed.

The third chamfered part 40 is formed in a stepped concave shape, and the chamfered part 41 on the side of the lightened part 18 is formed along the contour of the lightened part 18 via the inclined stepped part 41 a. It is formed on the outer green with a certain fixed width (narrow band shape). On the other hand, the chamfered portion 42 on the slot forming portion 17 side is formed continuously with the chamfered portion 41 on the side of the lightening portion 18 in a narrow band shape, and has a step portion 42 a similarly inclined. The first portion 17a and the second portion 17b are formed only on the outer edges along the respective contours. Therefore, the first part f standing 17a and the first part 17b are formed so that the outer surfaces except for the chamfered part 42 are convex with the same height as the both side surfaces 9a and 9b of the vane ring 9. Have been.

The drive shaft 3 has a driven pulley 19 for driving transmission attached to the other end protruding from the pump body 6. To be transmitted.

The one side plate 10 is pressed against the end face of the pump body 6, and at the pressed portion, as shown in FIG. 2, is connected to the pump body 2 side and to the suction passage 4 of the pump body 6. A pair of left and right suction ports 20 are formed. Further, a pressure chamber 22 into which hydraulic oil discharged from a discharge port 21 formed in the pump body 2 flows is provided between an outer peripheral surface of the pump body 2 and an inner peripheral surface of the pump cover 7. I have. The pressure chamber 22 is connected in parallel to a discharge passage 5 provided in the pump body 6 and a drain passage 24 formed on the opposite side of the discharge passage 5 in the radial direction.

A variable throttle mechanism 25 is provided in the discharge passage 5, while a drain valve 26 that responds to a pressure difference between the front and rear of the variable throttle mechanism 25 is provided at an upstream end of the drain passage 24. Have been.

The variable throttle mechanism 25 is provided with a spool accommodation hole 27 formed in the end face of the pump body 6 on the pressure chamber 22 side, and is accommodated in the spool accommodation hole 27 so as to be able to advance and retreat. A spool 28 for increasing or decreasing the opening area of the discharge passage 5 and a spring 29 for urging the spool 28 toward the pressure chamber 22 are provided.

The variable throttle mechanism 25 moves forward and backward by the balance between the hydraulic pressure of the pressure chamber 22 acting on one end of the spool 28 and the spring force of the spring 29, and the spool 28 moves to the side plate 10. The opening area of the discharge passage 5 is set to be the maximum at the initial position where it comes into contact. One discharge port 21 formed in the side plate 10 is opened at a position facing the end face of the spool 28.

On the other hand, the drain valve 26 includes a spool accommodation hole 30 formed in the end face of the pump body 6 on the pressure chamber 22 side, a spool 31 accommodated in the spool accommodation hole 30 so as to be able to advance and retreat, A spring 32 for urging the spool 31 toward the pressure chamber 22; an opening in the pressure chamber 22 according to the amount of retraction when the spool 31 retreats; And a drain port 33 forming an open end.

The pressure on the downstream side of the variable throttle mechanism 25 is introduced to the bottom 30 a side of the spool accommodation hole 30 via the pressure introduction passage 23. One end of the spool 31 faces the pressure chamber 22 side, so that the variable throttle is located before and after the spool 31. Since the pressure before and after the pressure mechanism 25 acts, the drain valve 26 controls the discharge flow rate from the drain port 33 to the drain passage 24 in accordance with the pressure difference before and after the pressure.

Therefore, according to this embodiment, while the rotation speed of the drive shaft 3 (Vanero 9) is low, the drain valve 26 is connected to the spring 3 2 while the variable throttle mechanism 25 opens the discharge passage 5 to the maximum. Since the drain port 33 is closed by the force of the pressure, the supply flow rate of the discharge passage 5 increases as the rotation speed increases.

Then, when the rotational speed of the drive shaft 3 increases to some extent and the differential pressure across the variable throttle mechanism 25 exceeds a set value, the spool 31 of the drain valve 26 is driven by the drain port 3 in response to the differential pressure. By opening 3 and discharging the hydraulic oil from the drain passage 24, an increase in the supply flow rate of the discharge passage 5 is suppressed.

Further, when the rotation speed of the drive shaft 3 increases from this state, the spool 28 of the variable throttle mechanism 25 retreats against the spring force of the spring 29 due to the hydraulic pressure of the hydraulic oil in the pressure chamber 22 and discharges. The opening area of the passage 5 is gradually reduced. As a result, the supply flow rate of the discharge passage 5 gradually decreases, and so-called flow-down characteristics can be obtained.

Further, according to this embodiment, the chamfered portions 42 of the first portion 17a and the second portion 17b of the slot forming portion 17 are not formed on both side surfaces, but are formed on the respective contours. Is formed only on the outer peripheral edge along the outer periphery, so that the other outer surface becomes convex at the same height as both side surfaces 9a and 9b of the vanello. Therefore, the gaps C, C between both side surfaces of the slot forming portion 17 and both side plates 10, 11 can be made as small as possible. The sealing function can be fully exerted on both sides of the shape.

As a result, leakage of hydraulic oil from the inner surfaces of both side plates 10 and 11 and the side of vane 16 is sufficiently prevented, and thus a decrease in pump efficiency is prevented. Moreover, each outer side except the chamfered portions 42 of both the first portion 17a and the second portion 17b Since the surface is convex, the high sealing function is exhibited, and the rigidity of the second portion 17b side can be maintained high, so that the supporting rigidity for each vane 16 increases. That is, in the vicinity of the discharge port 21, the hydraulic pressure becomes highest on the first portion 17 a side, and this high pressure is received on the side 16 b on the first portion 17 a side of the van 16, and this reaction force Is transmitted to the second portion 17b, but since the second portion 17b has high rigidity, the support rigidity for the vane 16 is increased, and stable support is obtained, and the slot is formed. The durability of the part 17 is improved.

Further, since the radius of curvature of the second chamfered portion 17d of the slot forming portion 17 is set to be larger than the radius of curvature of the first chamfered portion 17c, as described above, the parts feeder of During the transportation, when the lightening portion 18 and the slot forming portion 17 of the adjacent vane rotors 9 are fitted together, they can always be easily separated without tightly fitting each other. Has become. Therefore, the containment work is further facilitated.

The present invention is not limited to the configuration of each of the above embodiments.For example, forming the chamfered part 42 on the slot forming part 17 side along the contour is only on the first part 17a side. Alternatively, the second chamfered portion 42 may be formed only on the second portion 17b side. In this case, the other chamfered portion 42 is formed on the entire outer surface as in the conventional case.

Claims

The scope of the claims

1. a cam ring housed and arranged in the pump housing;

A mouth rotatably accommodated in the cam ring and rotatably driven by a drive shaft;

A plurality of slots formed in the outer peripheral portion of the rotor along the radial direction;

A vane held in each slot so as to be able to protrude and retract toward the inner peripheral surface of the cam ring;

A notch formed in a portion other than a slot forming portion in which the slot is formed on the outer peripheral surface of the rotor,

A vane pump having a concave chamfer formed on an outer edge of an outer peripheral portion of the rotor,

The slot forming portion formed in the convex shape includes a first portion on the rotor rotation side and a second portion on the opposite side to the rotation direction of the rotor around the slot, and a chamfer on the slot formation portion side. Is formed only on the outer edge along at least one of the contours of the first portion and the second portion, and the outer surface of one of the first portion and the second portion is formed by the chamfered portion. A vane pump formed in a convex shape having the same height as a rotor side surface on an inner peripheral side. ,

2. The chamfered portion on the side of the slot forming portion is formed only on an outer edge along the contour of the first portion, and the outer surface of the first portion is formed in a convex shape. The vane pump according to the above.

3. The chamfered portion on the side of the slot forming portion is formed only on the outer edge along the contour of the second portion, and the outer surface of the second portion is formed in a convex shape. The vane pump according to the above.

4. The chamfered portion on the slot forming portion side is formed on the outer edge along the contour of both the first portion and the second portion, and the outer surfaces of the first portion and the second portion are formed in a convex shape. I The battery according to claim 1,