WO2005003562A1

WO2005003562A1 - Vane pump

Info

Publication number: WO2005003562A1
Application number: PCT/JP2003/008619
Authority: WO
Inventors: Masaaki Busujima; Kunio Takahashi
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: CN100379990C; JPWO2005003562A1; CN1764784A

Abstract

A vane pump comprises a vane rotor (9) rotatably received in a cam ring (8), and vanes (16) held for projection and retraction in a plurality of slots (15) radially formed in the outer periphery of the vane rotor substantially at circumferentially equispaced intervals. The circumferential length (L) of a material-removed section (18) between two adjacent slot forming sections (17, 17) is set greater than the circumferential length (L1) of each slot forming section so that even if the material-removed sections and the slot forming sections of adjacent vane rotors fit together on a parts feeder, such fitting is not a tight fit but a loose fit. This prevents rotors being fed on the parts feeder from connecting to each other, thus preventing the efficiency of automatic assembly operation from lowering.

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 for this kind 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 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. Further, the rotor is connected to a drive shaft penetrated in the pump housing. Rotational force is transmitted to the drive shaft by a timing belt from a crankshaft of the engine via a driven pulley attached to the outer end side. When the vane rotor rotates with the rotation of the drive shaft, each vane rotates while protruding from the slot by the pressure of the back pressure chamber while the tip end of each vane slides on the inner peripheral surface of the cam ring. . With this, the hydraulic pressure flowing into the pump chamber between the vanes from the suction port formed in the pump housing is discharged to the discharge port while being compressed by the vanes, thereby performing the pumping operation. It has become. Incidentally, in the conventional vane pump, recently, a notch is formed intermittently on the outer peripheral surface of the outer peripheral portion of the mouth except the slot forming portion where the respective slots are formed. For example, there is one that satisfies the demand for cost reduction by reducing the material of rollers formed of a sintered alloy, and also has the effect of reducing the pulsation of the pump by increasing the volume of the pressure chamber. .

However, in the case where the notch portion is formed intermittently on the outer peripheral surface of the rotor, the circumferential length of each notch portion is substantially the same as the circumferential length of the convex slot forming portion. If many of the rotors are sintered, they are placed on the parts feeder on the manufacturing line and conveyed while slightly interfering with each other on the same plane. The other slot forming portions adjacent to each other are tightly fitted and connected to each other.

For this reason, the rotors connected to each other on the parts feeder are conveyed to the automatic assembling apparatus, and the workability of the automatic assembling is deteriorated. Disclosure of the invention

The present invention has been devised in view of the above-mentioned conventional technical problems, and the first invention has a notch formed at a portion other than a slot forming portion where a slot is formed on an outer peripheral surface of a rotor. In addition, the circumferential length of the notch between the adjacent slot forming portions is set to be larger than the circumferential length of each slot forming portion.

According to the present invention, since the circumferential length of the cutout portion is set to be larger than the circumferential length of the slot forming portion, many rotors formed by sintering are placed on the parts feeder and conveyed. Even if the rotors are close to each other and lightly interfere with each other and the slot forming part of the other rotor that is in contact with the notch in one mouth is so-called loose fitting instead of tight fitting. As a result, the rotors are not connected to each other, and are transported in a state of being separated from each other. As a result, each rotor is smoothly transported to the automatic assembling device by the parts feeder, thereby preventing a reduction in assembling workability.

A second invention is characterized in that the circumferential length of the slot forming portion is set to at least three times or more the opening length of the slot.

According to the present invention, even if the circumferential length of the slot forming portion is made as small as possible by the cutout portion formed on the outer peripheral surface of each rotor, the length is reduced to the opening length of the slot. Since it is three times or more, the rigidity of the slot forming portion is sufficiently ensured. Therefore, the pumping action of each vane caused by the rotation of the rotor makes it possible to sufficiently oppose a large load acting on the vane in the direction opposite to the rotating direction, thereby forming a slot. The occurrence of deformation of the part can be prevented.

According to a third aspect of the present invention, a first chamfered portion is formed in a rotor rotation direction of each slot forming portion formed in a convex shape by each of the cutout portions and in each outer edge opposite to the rotation direction. A second chamfered portion is formed between the base of the slot forming portion and the connecting portion of the notch, and a radius of curvature of the second chamfered portion is set to be larger than that of the first chamfered portion.

According to the present invention, as described above, the first chamfering of one rotor is performed when the adjacent rotors engage with the notch portion and the slot forming portion during the transport by the parts feeder of each rotor. Even if the part comes into contact with the other bevel, the second chamfered part has a larger radius of curvature than the first chamfered part, so it is always easily separated without tight fitting. It is in a state where it can be done. Therefore, the automatic assembling work is further facilitated. .

A fourth invention is characterized in that a length of a portion of the slot forming portion on the side opposite to the rotor rotation direction around the slot is set to be longer than a length of a portion on the mouth rotation direction side. And

According to the present invention, since the rigidity of the portion on the side opposite to the rotor rotation direction is increased, it can sufficiently cope with a large load in the direction opposite to the rotation direction by each vane. It becomes possible to support, and the durability of the rotor is improved. 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 van ring and the cam ring used 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 an enlarged view of a main part showing a second embodiment of the present invention. 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. The vane pump is applied to a pump as a supply source for supplying hydraulic equipment fo hydraulic pressure, such as a power steering device of a vehicle, and is fixed to a cylinder block of an internal combustion engine by a port as shown in Fig. 1. A pump housing 1, a pump body 2 disposed in the pump housing 1, and a drive shaft 3 having one end inserted into the pump housing 1.

As shown in FIGS. 1 and 2, the pump housing 1 comprises a block-shaped pump body 6 having a suction passage 4 and a discharge passage 5, and a pump cover 7 coupled to the pump body 6. A space for housing the pump body 2 is provided between the pump body 6 and the pump cover 7. .

As shown in FIGS. 1 to 3, the pump body 2 includes a cam ring 8 housed and disposed inside the pump cover 7, and a ventilator 9 rotatably provided inside the cam ring 8. A pair of side plates 10, 11 arranged on both sides of the cam ring 8.

The cam ring 8 is formed at approximately 180 ° on the outer peripheral surface as shown in FIG. The pump housing 1 is positioned in the circumferential direction by the location bins 13 and 13 fitted into the pair of small semicircular pin receiving grooves 8 b and 8 c, and the inner peripheral surface 8 a Are formed in a substantially elliptical shape.

The vane rotor 9 is integrally formed in a substantially disk shape by a sintered alloy, and separates a substantially annular pump chamber 14 between an outer peripheral surface and an inner peripheral surface 8 a of the cam ring 8. I have. In the center of the vane rotor 9, a selection hole 9a through which the one end 12a of the drive shaft 3 penetrates through the side plates 10 and 11 is formed. In the portion, 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 has a bottom in 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 toward the inner peripheral surface 8a of the cam ring 8. Further, as shown in FIGS. 3 to 6, the vane rotor 9 has an arc-shaped hollowed 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. 5, 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 between the adjacent slot forming portions 17, 17. The circumferential length L of each lightening portion 18 is set to be larger than the circumferential length L1 of each slot forming portion 17.

Further, the entire length L 1 of the slot forming portion 17 in the circumferential direction is set to be at least three times or more the opening length L 2 of the slot 15. Further, the slot 15 is formed substantially at the center of the slot forming portion 17 in the circumferential direction, and a portion 1 on the opposite side of the rotation direction of the vane rotor 9 about the slot 15 is formed. The lengths L 3 and L 4 in the circumferential direction of the portion 17 b on the rotation direction side are substantially the same as 7 a and the portion 17 b on the rotation direction side.

In addition, as shown in FIG. The outer edge of the rotor opposite to the rotation direction (the direction of the arrow)

(1) A chamfered portion (17c) is formed, and an arc-shaped second chamfered portion (17d) is formed between a base portion of the slot forming portion (17) and a connecting portion of the slotted portion (18). The radius of curvature R of the second chamfer 17d is set to be larger than the radius of curvature of the first chamfer 17c.

Further, the vane rotor 9 prevents burrs, which are easily generated when the vane rotor 9 is sintered and formed, in the circumferential direction inside the slot forming portion 17 and the lightening portion 18 on the outer peripheral portion. An annular third chamfered portion 17e is formed to perform the beveling.

A drive transmission pulley 19 is attached to the other end of the drive shaft 3 protruding from the pump body 6, and the power of the engine is transmitted through a belt (not shown) wound around the pulley 19. It has become.

The one side plate 10 is pressed against the end face of the pump body 6, and a pair of left and right suction ports 20 formed on the side of the pump body 2 is formed at the pressed portion, as shown in FIG. 2. It is connected to a suction passage 4 of the pump body.

A pressure chamber 22 into which hydraulic oil discharged from a discharge port 21 formed in the pump body 2 flows is provided between the outer peripheral surface of the pump body 2 and the inner peripheral surface of the pump cover 7. I have. The pressure chambers 22 are connected in line 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.

The discharge passage 5 is provided with a variable throttle mechanism 25, while a drain valve 26 is provided at the upstream end of the drain passage 24, the drain valve 26 being responsive to a differential pressure across the variable throttle mechanism 25. I have.

The variable throttle mechanism 25 has a spool housing 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 and 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 pump body 2 is open at a position of the side plate 10 facing the end face of the spool 28.

On the other hand, the drain valve 26 includes a spool housing hole 30 formed in the end face of the pump body 6 on the pressure chamber 22 side, and a spool 31 housed in the spool housing hole 30 so as to be able to move forward and backward. A spring 32 for urging the spool 31 toward the pressure chamber 22; and a drain passage 24 for opening the pressure chamber 22 according to the amount of retreat when the spool 31 retreats. And a drain port 33 which constitutes 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 pressure before and after the variable throttle mechanism 25 acts on the front and rear of the spool 31. The discharge flow rate from the drain port 33 to the drain passage 24 is controlled to increase or decrease according to the differential pressure of the pressure.

Therefore, according to this embodiment, while the rotation speed of the drive shaft 3 (the vane rotor 9) is low, the drain valve 26 is actuated by the spring 32 while the variable throttle mechanism 25 opens the discharge passage 5 to the maximum. (Thus, since the drain port 33 is closed, the supply flow rate of the discharge passage 5 increases as the rotational speed increases.)

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 changes the drain port 3 3 in response to the differential pressure. Since the operating oil is opened and the hydraulic oil is discharged 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 variable throttle mechanism 25 The spool 28 retreats against the spring force of the spring 29 by the hydraulic pressure of the hydraulic oil on the pressure chamber 22 side, and the opening area of the discharge passage 5 is gradually reduced. As a result, the supply flow rate of the discharge passage 5 gradually decreases, and a so-called flow-down characteristic can be obtained.

Further, according to this embodiment, since a plurality of hollow portions 18 are intermittently formed on the outer peripheral surface of the vane ring 9, the reduction of the metal material and the pulsation can be achieved. In addition, since the circumferential length L of each lightening portion 18 is set to be larger than the circumferential length L1 of each slot forming portion 17, a large number of sinter-formed vane rolls 9 are provided. Even if the slot forming part 17 of another adjacent vane rotor 9 fits into the thinned part 18 of one vane rotor 9 while the Instead, the vane rotors 9 are in a so-called loose fit state, so that the vane rotors 9 are not connected to each other and can be transported in a state of being separated from each other.

As a result, the parts are smoothly transported to the automatic assembling device by the respective parts feeders, thereby preventing a reduction in assembling workability.

Further, even if the circumferential length L 1 of the slot forming portion 1 によって is made as small as possible by the lightening portion 18, the length L 1 is changed to the opening length L 2 of the slot 15. Since it is set to three times or more, the rigidity of the slot forming portion 17 can be sufficiently ensured.

Therefore, the vane 16 must sufficiently oppose a large load acting on the vane 16 in the direction opposite to the rotational direction due to the pumping action (bump action) of each vane 16 accompanying the rotation of the vane rotor 9. As a result, the support strength of the vane 16 is increased, and the occurrence of deformation of the slot forming portion 17 can be prevented.

In addition, since the radius of curvature of the second chamfered portion 17 d of the slot forming portion 17 is set to be larger than that of the first chamfered portion 17 c, as described above, during the transport of each vane rotor 9 by the par feeder, When the lightening portion 18 of the adjacent vanes 9 and the slot forming portion 17 are fitted to each other, they do not fit tightly to each other. It is always in a state where it can be easily separated. Therefore, the subsequent automatic assembling work is further facilitated.

FIG. 6 shows a second embodiment, in which the length L3 of the portion 17a of the slot forming portion 17 on the opposite side to the direction of rotation of the vane rotor 9 about the formation position of the slot 15 is defined as a length. This is set to be longer than the length L4 of the part 17b on the rotation direction side of the ninth and night 9th.

Therefore, since the rigidity of the portion 1 Ίa on the opposite side to the rotation direction of the vane rotor 9 becomes larger, it is necessary to sufficiently support the large load in the opposite direction to the rotation direction by the vanes 16. And the durability of the rotor is improved. The present invention is not limited to the configurations of the above embodiments, and for example, the depth of the lightening portion 18 and the length in the circumferential direction can be arbitrarily changed.

Claims

The scope of the claims

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

A rotor rotatably housed 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 of the slots so as to be able to protrude and retract toward the inner peripheral surface of the cam ring.

A notch is formed in a portion of the outer peripheral surface of the rotor other than the slot forming portion in which the slot is formed, and the circumferential length of the notch between the adjacent slot forming portions is defined as A vane pump characterized in that the length is set to be larger than the circumferential length of the slot forming portion.

2. The vane pump according to claim 1, wherein the circumferential length of the slot forming portion is set to at least three times or more the opening length of the slot.

3. A first chamfered portion is formed on each outer edge of each slot forming portion formed in a convex shape by each of the cutout portions in the rotating direction and on the opposite side to the rotating direction, and the slot is formed. Claim 1 characterized in that a second chamfered portion is formed between the base of the portion and the connecting portion of the notch, and the radius of curvature of the second chamfered portion is set larger than the first chamfered portion. Or the vane pump described in 2.

4. The length of a portion of the slot forming portion on the side opposite to the rotor rotation direction around the slot is set to be longer than the length of a portion on the rotor rotation direction side. The vane pump according to any one of to 3.