JP2579435Y2 - Variable displacement vane pump - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable displacement vane pump used for a power steering device of an automobile.

[0002]

2. Description of the Related Art Generally, in a vane pump, a plurality of vanes are mounted on a rotatable rotor so as to be able to protrude and retract in a substantially radial direction. When the rotor rotates in a cam ring, each vane slides on the inner cam surface of the cam ring. The reciprocating operation is repeated, thereby increasing or decreasing the volume between adjacent vanes to perform a pumping action. In the case of a variable displacement vane pump, the rotation center of the rotor and the center of the inner cam surface are assembled so as to be eccentric to each other, and the rate of change in the volume between adjacent vanes is controlled by controlling the amount of eccentricity. , Thereby adjusting the discharge flow rate of the hydraulic oil.

As this type of variable displacement vane pump,
Conventionally, the one shown in FIGS. 6 and 7 has been developed.

In this vane pump, a cam ring 2 accommodating a rotor 1 is rotatably attached to a pump body 3 via a pin 4, while an arm 5 extending radially outward of the cam ring 2 is provided. The control piston 7 is linked to the control piston 7 via a connecting pin 6.
However, when actuated by a differential pressure across an orifice (not shown) provided in the pump discharge side passage, the cam ring 2 rotates eccentrically with respect to the rotor 1 in conjunction with the actuation. In the case of this vane pump, a long hole 8 as a radial hole is formed in the center of the side surface of the control piston 7 (see FIG. 7), and the end of the connection pin 6 attached to the arm 5. Is inserted into the elongated hole 8 so that the control piston 7 and the cam ring 2 are interlocked. That is, since the control piston 14 moves linearly in the cylinder 14 and the arm 5 swings in an arc around the pin 4, the trajectories of the two do not exactly coincide with each other. Are allowed to move in the long hole 8 so that they can smoothly work together without restricting the movement of each other.

[0005] This similar technique is disclosed in, for example, Japanese Patent Application Laid-Open No.
No. 1607 and Japanese Utility Model Laid-Open No. 59-159793.

[0006]

However, in the case of the conventional variable displacement vane pump described above, since the processing accuracy of the long hole 8 is limited, it is necessary to ensure that the connecting pin 6 can move within the long hole 8. Then, a gap is formed between the side wall of the elongated hole 8 in the width direction and the connecting pin 6, and as a result, play occurs between the connecting pin 6 and the control piston 7 when the pump is operated.
This rattling causes noise and causes abrasion between the two.

In view of this, the present invention provides a variable connecting pin mounted on a cam ring which can be assembled to a control piston without gaps so that there is no gap between the connecting pin and the control piston when the pump is operated. It is intended to provide a positive displacement vane pump.

[0008]

According to the present invention, as a means for solving the above-mentioned problems, a rotor having a plurality of vanes mounted so as to be able to protrude and retract in a substantially radial direction, and this rotor is housed inside, and A cam ring that rotates eccentrically, and a control piston that controls the amount of rotation of the cam ring. A connecting pin attached to the cam ring is inserted into a radial hole of the control piston, and the cam ring and the control piston are separated. In the variable displacement vane pump linked to each other, an axial hole intersecting with the radial hole is provided in the control piston, and a pair of support pins whose end faces face the radial hole are provided in the axial hole. Attachment, the connecting pin was held between the end faces of both support pins.

[0009]

When attaching a pair of support pins to the axial hole of the control piston, the front and rear positions of at least one of the support pins are adjusted so that the end faces of both support pins abut the side faces of the connection pins. .

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. It is to be noted that the same reference numerals are used for the same portions as the conventional one shown in FIGS.

In the drawings, reference numeral 3 denotes a pump body. The pump body 3 includes a front body 3a, a center body 3b, a side plate 3c, and a rear cover 3.
d. The drive shaft 10 is mounted on the pump body 3.
Are rotatably supported, and the rotor 1 is supported and coupled to the drive shaft 10 so as to be integrally rotatable. The rotor 1 has a plurality of slots 11 formed on the outer peripheral side in a substantially radial shape, and a vane 12 is housed in each of the slots 11 so as to be able to protrude and retract.

Reference numeral 2 denotes a cam ring for accommodating the rotor 1 therein.
Is provided with a circular inner cam surface 2a with which the front end of the inner cam surface slides. The cam ring 2 is housed in the internal space of the pump body 3, and one end of the cam ring 2 is
a and a rear cover 3d rotatably attached to the other end of the arm 5. A turning operation arm 5 extends radially outward from the other end.
Is attached. The center O 'of the inner cam surface 2a of the cam ring 2 is eccentric with respect to the rotation center O of the rotor 1. This vane pump is eccentric in both centers O' and O as described above. When the rotor 1 rotates while the leading end of the vane 12 slides on the inner cam surface 2a, each vane 12 repeats the protruding and retracting operation in the slot 11, thereby increasing or decreasing the volume between the adjacent vanes 12, 12 continuously. Performs a pumping action. In addition, 2 in FIG.
Reference numerals 0 and 21 indicate a suction port and a discharge port formed on the rear cover 3d.

Reference numeral 13 denotes a control piston for controlling the amount of eccentric rotation of the cam ring 2. The control piston 13 includes a cylinder 14 formed on the front body 3a.
The first liquid chamber 14a and the second liquid chamber 14
b. And the first liquid chamber 1
The liquid pressure before and after an orifice (not shown) provided in the pump discharge side passage is respectively introduced into the 4a and the second liquid chamber 14b, and the control piston 13 responds to the pressure difference before and after this orifice. To work.

A circular radial hole 13a is formed in the center of the side surface of the control piston 13, and the end of the connecting pin 6 is inserted into the radial hole 13a. . Furthermore, an axial hole 30 orthogonal to the radial hole 13a is formed in the axial center of the control piston 13. The axial hole 30 is provided in the control piston 13.
A hole opening 30a drilled so as to penetrate one end face of the control piston 13 and a hole bottom 30 drilled from the radial hole 13a toward the other end face of the control piston 13.
The support pins 15a and 15b having flat end faces are press-fitted into the hole opening 30a and the hole bottom 30b, respectively. Each of the support pins 15a and 15b protrudes inside the radial hole 13a by a predetermined amount.
Are slidably sandwiched between the side surfaces of the main body. The support pins 15a and 15b form an elongated hole as shown in FIG. 5 together with the radial hole 13a, so that the connecting pin 6 can move in the elongated hole. When press-fitting the support pins 15b and 15a into the hole bottom 30b and the hole opening 30a, respectively, the front and rear of the support pins 15a and 15a are so set that the distance between the support pins 15b and 15a is the same as the outer diameter of the connection pin 6. The position is adjusted so that the end faces of both support pins 15a, 15b reliably contact the side faces of the connecting pin 6 without any gap.

Since the variable displacement vane pump has the above-described structure, when the rotor 1 rotates together with the drive shaft 10 in a predetermined direction, the pumping action accompanying the movement of each vane 12 causes discharge from the discharge area in the cam ring 2. While the hydraulic oil is discharged to the port 21, the pressure difference between the front and rear of the orifice provided in the pump discharge side passage is controlled by the control piston 13.
And the control piston 13 operates in accordance with the pressure difference between the front and rear. When the control piston 13 is operated in this manner, the cam ring 2 is interlocked with the control piston 13 via the connecting pin 6, whereby the eccentric amount of the cam ring 2 with respect to the rotor 1 is adjusted appropriately. When the control piston 13 and the cam ring 2 interlock, the radial holes 13a and the support pins 15
The connecting pin 6 moves in the long hole formed by the holes 15a and 15b.

In the case of this vane pump, by adjusting the axial position of the support pin 15a press-fit into the axial hole 30 of the control piston 13, the end surfaces of the support pins 15a and 15b are brought into contact with the side surfaces of the connecting pin 6 without any gap. Since the control piston 13 is in contact, there is no play between the connecting pin 6 and the control piston 13 when the control piston 13 is operated. For this reason, noise due to the rattling, wear between the connecting pin 6 and the control piston 13 and the like do not occur.
In particular, if only the support pins 15a and 15b are formed of an iron material and the control piston 13 is formed of an aluminum material, it is possible to achieve both a reduction in the weight of the control piston 13 and an improvement in durability. In other words, if only the support pins 15a and 15b are formed of an iron material, the weight of the control piston 13 is reduced, and the contact portions (end faces of the support pins 15a and 15b) with the connection pins 6 are worn or thermally expanded. Deformation is less likely to occur. In addition, in this vane pump, the back and forth position of the support pin 15a is adjusted so that the backlash between the connecting pin 6 and the control piston 13 is eliminated. There is also an advantage that it is not necessary to perform a high process, and the production becomes easier accordingly.

The embodiment of the present invention is not limited to the above embodiment. For example, in the above embodiment, the support pins 15a and 15b are press-fitted into the axial hole 30. The attachment of the support pins 15a, 15b to the connector 30 is not limited to press-fitting, but may be other means such as screwing.

[0018]

As described above, according to the present invention, the control piston is provided with an axial hole crossing the radial hole, and a pair of support pins each having an end face facing the radial hole are attached to the axial hole. Since the side faces of the connecting pin are sandwiched between the end faces of the two supporting pins, the connecting pin is securely assembled to the control piston by adjusting the front and rear positions of at least one of the supporting pins during assembly. I can do it. Therefore, rattling does not occur between the connecting pin and the control piston during operation of the pump, and problems such as generation of noise and acceleration of wear between both members due to the rattling do not occur.

[Brief description of the drawings]

FIG. 1 is a sectional view taken along the line AA of FIG. 5 showing an embodiment of the present invention.

FIG. 2 is a sectional view showing the embodiment.

FIG. 3 is a sectional view taken along the line BB of FIG. 2 showing the embodiment.

FIG. 4 is a front view showing the same embodiment.

FIG. 5 is a front view showing the same embodiment.

FIG. 6 is a sectional view showing a conventional technique.

FIG. 7 is a front view showing the same technology.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... rotor, 2 ... cam ring, 6 ... connecting pin, 12 ... vane, 13 ... control piston, 13a ... radial hole, 15a, 15b ... support pin, 30 ... axial hole.

Claims (1)

(57) [Scope of request for utility model registration] 1. A rotor in which a plurality of vanes are mounted so as to be able to protrude and retract in a substantially radial direction, a cam ring accommodating the rotor therein and eccentrically rotating with respect to the rotor, and a control device for controlling a rotation amount of the cam ring. A variable displacement vane pump comprising a piston, wherein a connection pin attached to the cam ring is inserted into a radial hole of the control piston, and the cam ring and the control piston are linked to each other.
The control piston is provided with an axial hole intersecting with the radial hole, and a pair of support pins, each end face of which faces the radial hole, is attached to this axial hole. A variable displacement vane pump characterized by sandwiching the sides of a vane.