JPH0311097Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a flow rate regulating valve used in a steering force control device of a power steering device, etc.

The applicant of this application previously filed a patent application for this flow rate regulating valve.
No. 57-150250 has already proposed a valve 1 shown in FIG. 1, and this figure shows the flow rate regulating valve 1 used in a power steering device.

First, to explain the outline of the power steering device, the pump P sucks working fluid from the reservoir R, discharges it, and supplies it to the control valve V. The control valve V performs the steering operation in response to the steering load during steering operation. Depending on the direction, one chamber of the power cylinder C is connected to the circuit L _S from the pump P, and the other chamber is connected to the circuit L _D to the reservoir R.
is operated fluidly in the steering direction. In this way, the power cylinder C provides power assist to the driver's steering operation in the steering direction, enabling light power steering.

Next, the flow rate regulating valve 1 will be briefly explained. It has a variable throttle part 2 inserted into a bypass circuit connecting circuits L _S and _LD , and its opening area can be varied by the stroke of a valve body 3. do. The stroke of the valve body 3 is determined by a plunger 6 that is displaced to a position where the magnetic force of the linear solenoid 4 and the spring force of the spring 5 are balanced.
The magnetic force of the linear solenoid 4 is controlled by the controller 7. The controller 7 determines the amount of energization to the linear solenoid 4 based on the calculation results of the vehicle speed signal, the working fluid temperature signal, the steering speed signal, etc., and causes the linear solenoid to generate a magnetic force according to the amount of energization. In response to this magnetic force, the plunger 6 is moved to the left in the figure to move the valve body 3 in the same direction, thereby determining the opening area of the variable throttle section 2.

In this way, the working fluid flowing from the pump P to the control valve V is partially determined by the opening area of the variable throttle section 2, bypassing this, and returning to the reservoir R, thereby reducing the steering force to the variable throttle section 2. It can be controlled according to the opening area, that is, vehicle speed, working fluid temperature, and steering speed.

Note that the flow rate of the bypass will vary if the differential pressure across the variable throttle section 2 changes, making the above control inaccurate.
It is kept at a constant value by

By the way, in the case of such a flow rate regulating valve,
Unless the pressures acting on both ends of the valve body 3 are balanced and the pressures acting on both ends of the plunger 6 are also not balanced, accurate action cannot be performed. For this reason, normally, a communication hole 3a is provided in the valve body 3, and the valve body 3 is
The working fluid is introduced into a chamber 9 where the abutting end of the plunger 6 exists, and the working fluid also enters a containment chamber 10 where the other end of the plunger 6 faces.

However, in this case, there is a problem in that air in the working fluid tends to accumulate in the containment chamber 10, where there is relatively no flow of working fluid because of the presence of a bearing that supports the plunger. Since the chamber 10 is a containment chamber, this air cannot be removed even if the power steering device is bled of air. When the valve vibrates due to the excitation force from the valve, the viscosity of the working fluid quickly prevents the vibration from being suppressed, resulting in inaccurate operation of the flow rate regulating valve.

The present invention was based on the idea that if an openable and closable air vent hole is provided that communicates the containment room with the outside, the air accumulated in the containment room can be completely removed and the above-mentioned problems can be solved. The present invention aims to provide a concrete flow rate regulating valve.

Hereinafter, the present invention will be explained in detail with reference to illustrated embodiments.

FIG. 2 shows an embodiment of the present invention, in which the same parts as in FIG. 1 are designated by the same reference numerals. First of all,
To provide a supplementary explanation of the flow rate adjustment valve 1, a variable throttle part 2 is provided in which the valve body 3 is slidably fitted into the valve body 11 and the opening area changes depending on the stroke of the valve body 3.
Set. In addition, a spring 5 is interposed between the valve body 3 and the valve body 11, so that the valve body 3 is connected to the variable throttle portion 2.
is biased in the direction of increasing opening (to the right in the figure). The linear solenoid 4 is fixed in a solenoid case 12 which is connected to the valve body 11 and defines a chamber 9 therebetween, and the plunger 6 passes through the linear solenoid coaxially. The plunger 6 is axially movably supported by a pair of linear ball bearings 13 on a solenoid case 12 and an adjuster case 14 attached thereto. A ferromagnetic actuator 15 is fitted to the plunger 6 so that the plunger 6 can be moved to the left in the figure by the magnetic force of the linear solenoid 4.

One end of the plunger 6 is brought into contact with the valve body 3, and the spring seat 16 is fitted to the other end of the plunger 6. An adjuster bolt 17 is screwed into the adjuster case 14 to define a containment chamber 10.
A spring 18 is compressed between the spring seat 7 and the spring seat 16. Thus, the spring reaction force of the spring 18 can be adjusted by tightening the adjuster bolt 17 by rotating it, and the valve body 3 and plunger 6 are normally balanced and supported between the springs 5 and 18. Then, by adjusting the spring reaction force of the spring 18 using the adjuster bolt 17, the valve body 3 and the plunger 6 generated due to the change in the magnetic force of the linear solenoid 4 are adjusted.
By changing the stroke amount, that is, the amount of change in the opening area of the variable throttle section 2, the flow rate regulating valve 1 and its flow rate change characteristics can be adjusted to a predetermined value, and the adjuster bolt 17 is fixed at this adjusted position. Use lock nut 19 for protection.

In the present invention, an air vent hole that can be opened and closed is provided to communicate the containment chamber 10 with the outside, but in this example, this air vent hole is provided in the radial hole 20 provided in the adjuster bolt 17 and in the adjuster case 14. radial hole 21. Radial hole 2
0 is disposed at the tip end of the adjuster bolt 17 that is tightly fitted into the adjuster case 14, and is opened into the outer circumferential surface of the adjuster bolt 17 at the tightly fitted portion and into the containment chamber 10. Further, the radial hole 21 is connected to the adjuster bolt 1 relative to the adjuster case 14.
7, and extends between the inner and outer circumferential surfaces of the adjuster case 14.

In such a configuration, the outer end of the radial hole 20 is closed by the inner circumferential surface of the adjuster case 14, and the working fluid in the containment chamber 10 is channeled through the radial hole 2.
However, in order to ensure this, it is preferable to provide a seal ring 22 on the outer circumferential surface of the close fitting portion at the tip of the adjuster bolt 17.

In the configuration of this example, when removing air accumulated in the containment chamber 10, the lock nut 19 is first removed.
, and then loosen the adjuster bolt 17 in the removal direction. As a result, the radial holes 20 come into communication with the radial holes 21, and the working fluid in the containment chamber 10 can be removed together with air through these holes to perform air extraction. After removing the air, screw in the adjuster bolt 17, readjust the spring reaction force of the spring 18 to be the same as before, and tighten the lock nut 19 to complete the work.

Incidentally, in this example, a particularly great effect can be obtained when the flow rate regulating valve 1 is arranged horizontally as shown in the figure.

However, in this example, the adjuster bolt 1 is
7 is required and the work is troublesome, and if possible, it is preferable to be able to bleed air without moving the adjuster bolt 17. FIG. 3 shows an example of a configuration that meets this requirement. In this example, a spring seat 23 is slidably fitted into a counterbore hole 17a formed on the tip surface of the adjuster bolt 17, and a spring 18 is fitted into this. Seat the matching end. A notched groove 23a is formed on the outer peripheral surface of the spring seat 23, and a seal ring 24 that closes this notched groove is interposed between the spring seat 23 and the bottom surface of the counterbore hole 17a. Further, a center through hole 25 extending from the bottom of the counterbore 17a is formed in the adjuster bolt 17, and this is closed with a blind plug 26.

In the configuration of this example, the seal ring 24 is usually compressed by the spring 18 via the spring seat 23, and the notch groove 23a is cut off from communicating with the center through hole 25, and the inside of the containment chamber 10 is accessed from this through hole. The working fluid will not leak outside. Further, even if the working fluid should reach the through hole 25 due to damage to the seal ring 24, the blind plug 26 can prevent this from leaking to the outside.

To remove the air inside the containment chamber 10, first remove the blind plug 26, and then remove the through hole 2.
A rod-shaped tool is inserted into 5 to push the spring seat 23 against the spring 18 to separate the spring seat 23 from the seal ring 24. At this time, the notched groove 23a communicates with the through hole 25, through which the air in the containment chamber 10 can be removed to the outside together with the working fluid, and air can be vented. After removing the air, the rod-shaped tool is pulled out from the through hole 25, and the blind plug 26 is fitted into it to complete the work.

In the configuration of this example, the adjuster bolt 17
Since air can be bleed without moving at all, there is no need to readjust the adjuster bolt 17 to the same screw-in position as when assembling the flow rate regulating valve 1 after air bleed, and the work can be done easily and in a short time. . Further, in this example, the flow rate adjustment valve 1 can provide a great effect, especially when the flow rate adjustment valve 1 is installed vertically so that the containment chamber 10 is upward.
In this case, in order to make the work easier and in a shorter time, a push rod 27 is provided integrally protruding from the spring seat 23 as shown in FIG.
It is preferable to loosely fit this into the through hole 25 and project it to the outside. With this configuration, the push rod 27 can be pushed in to bleed air, and there is no need to use tools, so the bleed operation can be carried out more easily and in a shorter time.

Thus, as described above, the flow rate regulating valve of the present invention is provided with air vent holes 20, 21 (25) that can be opened and closed to communicate between the containment chamber 10 and the outside, so that the containment chamber 10 can prevent fluid flow due to the presence of the plunger support bearing. This containment room 10 is unlikely to occur.
The air accumulated inside can be completely removed, and even when the plunger 6 vibrates due to the excitation force from the valve body 3,
This vibration can be quickly suppressed by the viscosity of the working fluid, allowing the flow rate regulating valve to operate accurately.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view showing the flow rate regulating valve previously proposed by the applicant installed in a power steering device;
The figure is a sectional view showing an example of the flow rate regulating valve of the present invention.
This figure is a sectional view similar to FIG. 2 showing another example of the present invention, and FIG. 4 is a sectional view of a main part showing a modification of the flow rate regulating valve shown in FIG. 3. 1...Flow rate adjustment valve, 2...Variable throttle section, 3...
Valve body, 4... Linear solenoid, 5, 18... Spring, 6... Plunger, 10... Containment chamber, 1
1...Valve body, 12...Solenoid case, 13
... Linear ball bearing, 14 ... Adjuster case, 15 ... Actuator, 17 ... Adjuster nut, 19 ... Lock nut, 20, 21 ...
Radial hole (air vent hole), 22... Seal ring, 23... Spring seat, 23a... Notch groove, 24...
... Seal ring, 25 ... Center through hole (air vent hole), 26 ... Blind plug, 27 ... Push rod.

Claims (1)

[Claims for Utility Model Registration] A plunger to which an actuator is fixed is supported by a bearing so as to be displaceable in the axial direction, and by controlling the axial position of the plunger via the actuator, one end of the plunger can move the valve body. The housing chamber of the actuator and the bearing are configured to change the opening area of the variable restrictor for fluid flow rate adjustment by moving the valve, and to cause the fluid pressure acting on the one end of the plunger to also act on the other end of the plunger. In the flow rate regulating valve, the other end of the plunger faces a containment chamber to which the fluid pressure is successively introduced, and an openable and closable valve that appropriately communicates the containment chamber separated from the actuator storage chamber by the bearing with the outside. A flow rate regulating valve characterized by having an air vent hole.