JP2528041Y2 - Liquid pump flow control valve - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flow control valve of a liquid pump used in a power steering device for an automobile.

[0002]

2. Description of the Related Art This type of flow control valve is disclosed in
As shown in JP-A-6-29088, the discharge liquid of the pump is guided to a spool chamber having an open drain passage, and the drain passage is opened and closed by a spool reciprocating in the spool chamber. By returning excess fluid from the drain passage to the reservoir, a predetermined amount of hydraulic fluid is guided to the power steering device.

[0003]

However, in the above-mentioned prior art, one drain passage is opened in the inner periphery of the spool chamber. Therefore, when the hydraulic fluid guided into the spool chamber is returned from the drain passage to the reservoir by the movement of the spool, the spool is biased toward the drain passage by the flow of the hydraulic fluid. As a result, the inner surface of the spool chamber may be unevenly worn due to the biasing force when the movement of the spool is not smooth or when the spool chamber is formed of a soft material such as an aluminum alloy material.

[0004]

SUMMARY OF THE INVENTION In view of the above circumstances, the present invention provides a spool chamber communicating with a discharge side of a pump, a spool reciprocatingly sliding in the spool chamber, and an opening in the spool chamber. A drain passage controlled to be opened and closed by the spool, wherein the flow passage control valve guides a part of the pump discharge liquid to the drain passage by sliding the spool. plurality opened so Rutotomoni, with the drain passage said spool
90 ° on the discharge side of the pump
The configuration is as follows.

[0005]

[Action] By opening the drain passage by the spool,
Part of the discharge liquid guided to the spool chamber flows into a plurality of drain passages that are opened at equal intervals in the circumferential direction of the spool chamber, and thereby the discharge flow rate is controlled. At this time, when the working fluid flows into the drain passage from the spool chamber, the working fluid flows in the radial direction, and the force acting on the spool due to the flow of the working fluid is balanced, so that no biasing force acts on the spool. As a result, the spool operates smoothly and controls the flow rate. Also, drain passage and spool chamber
Angle at the discharge side of the pump should be 90 ° or less.
Flow from the spool chamber on the discharge side to the drain passage
Spool may be pushed axially by incoming fluid
The area of the drain passage opening increases unnecessarily because
Never.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a view showing a vane pump to which a flow control valve according to the present invention is applied. In FIG.
The axial hole, 3 a driving shaft inserted into the shaft hole 2, 4 denotes a bearing. Reference numeral 5 denotes a pump body connected to the distal end of the drive shaft 3. The pump body 5 includes a cam ring 6, a rotor 7 rotating in the cam ring 6, and a vane 8 attached to the rotor 7 and capable of moving in and out in the radial direction. And side plates 9a and 9b attached to both sides of the cam ring 6 as main elements. A cover 10 covers the pump body 5 and forms a discharge chamber 11 therein.
It is attached to the end. Reference numeral 12 denotes a suction hole for guiding a working liquid in a reservoir tank (not shown) into the pump body 5.
Reference numeral 13 denotes a discharge hole through which a discharge liquid of the pump is guided through a discharge port 14 and an orifice 15, and further, the discharge liquid is guided to a hydraulic device (not shown). The discharge liquid is also guided from the discharge port 14 into the discharge chamber 11.

Reference numeral 16 denotes a flow control valve.
Defines a spool chamber 17 that opens into the discharge chamber 11 of the pump, slidably inserts a spool 18 into the spool chamber 17, and provides a spring 20 for urging the spool 18 toward a stopper 19 side. It is. Reference numeral 21 denotes a pressure introduction hole for guiding the pressure in the discharge hole 13 into the spool chamber 17. Reference numeral 22 denotes a drain passage. As shown best in FIG. 3, the drain passage 22 has a plurality of openings at substantially equal intervals in the circumferential direction of the spool chamber 17, and two openings are symmetrical in the present embodiment. The suction port 12 communicates with the reservoir tank (not shown) and the suction port 24 through the groove 23. The drain passage 22
Is connected to the spool chamber 17 as shown in FIG.
The angle between the pump and the discharge chamber 11 is 90 ° or less.
In this embodiment, the angle is approximately 75 °.

In this configuration, when the rotor 7 of the pump body 5 is driven to rotate by the drive shaft 3, the working chamber C formed between the vanes 8 expands and contracts, and hydraulic fluid is sucked from a reservoir tank (not shown). After being sucked into the pump body 5 through the hole 12 and the suction port 24 and subjected to a pumping action, it is guided to a hydraulic device such as a power steering device (not shown) through the discharge port 14, the orifice 15 and the discharge hole 13. At this time, the flow control valve 16 operates as follows.
That is, the discharge liquid of the pump is also guided into the discharge chamber 11, and the pressure acts on the spool 18 of the flow control valve 16. However, when the rotation speed of the rotor 7 is equal to or less than the predetermined rotation speed and the discharge amount of the pump is small, the differential pressure generated before and after the orifice 15 is small, and
1 and is stopped with the stopper 19 in contact with the end of the cam ring 6. Therefore, in this case, the drain passage 22 opening to the spool chamber 17 is closed by the body of the spool 18, and the entire amount of the pump discharge liquid is guided to a hydraulic device (not shown). On the other hand, when the rotation speed of the rotor 7 increases and the discharge amount reaches a predetermined amount, the differential pressure generated before and after the orifice 15 increases, and the spool 18 moves rightward in FIG. Then, the drain passage 22 is opened. As a result, a part of the discharged liquid guided from the discharge chamber 11 into the spool chamber 17 is returned to the suction hole 12 and a reservoir tank (not shown) through the drain passage 22, and as a result, a predetermined flow rate is guided to the hydraulic device. It is controlled as follows.

Here, when the discharge liquid guided into the spool chamber 17 returns from the drain passage 22 to a reservoir tank (not shown), a biasing force due to the flow acts on the spool 18. However, in this embodiment, since two drain passages 22 are opened at equal intervals in the circumferential direction of the spool chamber 17, the hydraulic fluid flows symmetrically from the spool chamber 17 in the radial direction. The forces acting on the spool 18 due to the flow are balanced, so that no biasing force acts on the spool 18. As a result, the spool 18 operates smoothly in the spool chamber 17, and there is no uneven wear in the spool chamber 17. Also, the drain passage 22 has a spool
Since it is inclined toward the discharge chamber 11 with respect to the chamber 17,
The spool 18 is pushed in the axial direction by the flow of liquid.
And the opening area of the drain passage 22 increases unnecessarily.
And achieve the desired flow control.

[0011]

As described in detail above, according to the present invention, a spool chamber communicating with the discharge side of the pump, a spool reciprocatingly sliding in the spool chamber, an opening in the spool chamber, and the spool A flow path control valve for guiding a part of the pump discharge liquid to the drain passage by sliding the spool, wherein a plurality of the drain passages are provided at substantially equal intervals in a circumferential direction of the spool chamber. opened so Rutotomoni, and said drain passage and said spool chamber
The angle made by 90 degrees or less on the discharge side of the pump makes it possible to balance the forces acting on the spool when the liquid guided to the spool chamber flows into the drain passage.
No biasing force is applied to the spool. Therefore, the spool operates smoothly and does not cause uneven wear in the spool chamber. Also, the spool is pushed in the axial direction.
And the drain passage opening area is unnecessarily reduced.
There is no increase. Excellent durability and stability
A flow control valve having the above control characteristics can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view of a vane pump to which a flow control valve according to the present invention is applied.

FIG. 1 is a sectional view taken along line II-II.

FIG. 3 is a sectional view taken along line III-III of FIG.

FIG. 4 is a sectional view taken along line IV-IV of FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Discharge chamber 12 Suction hole 13 Discharge hole 16 Flow control valve 17 Spool chamber 18 Spool 22 Drain passage

Claims (1)

(57) [Scope of request for utility model registration] A spool chamber that communicates with a discharge side of a pump; a spool that reciprocates in the spool chamber; and a drain passage that opens into the spool chamber and is controlled to open and close by the spool. wherein the flow control valve directing a part of the pump discharge fluid to the drain passage by sliding, Rutotomoni was plurality opened at substantially equal intervals the drain passage in the circumferential direction of the spool chamber, and said drain passage spray
90 ° on the discharge side of the pump
A flow control valve characterized by the following .