KR100475921B1 - fluid flow control device of hydraulic steering system - Google Patents

Abstract

According to the present invention, the fluid flow control device in the hydraulic power steering system can impose appropriate restrictions on the flow direction and speed of the fluid, thereby ensuring smooth power steering operation and effectively suppressing the taste and kickback and improving the steering stability of the vehicle. To help.

Description

Fluid flow control device of hydraulic steering system

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for controlling the flow of fluid used in a hydraulic power steering system of a vehicle, and more particularly, to reduce shimmy and kick back of the vehicle, and to improve steering stability. To a fluid flow control device.

Figure 1 shows the main configuration of a conventional hydraulic power steering system according to the prior art.

The pinion shaft 102 linearly moves the rack 100 by being rotated by the driver's steering wheel rotational force, a power steering pump 106 for pumping oil from the oil reservoir 104, and the power steering pump 106. It is composed of a control valve 110 and the like for adjusting the state of transmitting the hydraulic pressure from the power to the power cylinder (108).

In the hydraulic power steering system as described above, when the driver provides steering force to the steering wheel, the torsion bar 112 of the control valve 110 transmits the steering force to the pinion shaft 102 so that the rack 100 When the torsion bar 112 is twisted by the reaction force transmitted from the wheel and the steering force of the driver, the pinion valve shaft 114 that is rotated integrally with the upper side of the torsion bar 112 is torsion bar ( The state in which the hydraulic pressure from the power steering pump 106 is transmitted to both sides of the power cylinder 108 is formed while forming a rotation angle relative to the valve 116 that is integrally rotated with the lower side of 112.

However, since the power steering system configured and operated as described above does not control the flow direction or speed of the fluid provided from the control valve 110, the vibration or shock acting on the wheel side is reversed through the fluid. If it acts as a steering system as an input to cause phenomena such as kickback or shimmy, this cannot be controlled.

Of course, conventionally, a method of suppressing the sima kickback with an appropriate configuration of the suspension geometry has been attempted, but there is a problem that the effect is limited.

Accordingly, the present invention has been made to solve the problems described above, it is possible to impose an appropriate restriction on the flow direction and speed of the fluid in the hydraulic power steering system to ensure a smooth power steering operating state while effectively suppressing the stiff and kickback It is an object of the present invention to provide a fluid flow control device of a hydraulic steering system to improve the steering stability of the vehicle.

Fluid flow control device of the hydraulic steering system of the present invention for achieving the above object has a first port formed to receive the hydraulic pressure from the control valve, and a second port formed to supply the hydraulic pressure from the control valve to the power cylinder. One valve housing;

A plunger installed in the valve housing to linearly slide by the hydraulic pressure provided from the first port;

A spring which grips the plunger toward the first port;

A stopper for limiting the movement range toward the first port of the plunger;

And a spring plate installed at an end portion of the plunger facing the first port to form a micro clearance of the fluid together with the inner wall surface of the valve housing.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

Figure 2 shows the structure of the fluid flow control device of the hydraulic steering system according to the present invention, the device is installed on each of the hydraulic pipe connected to both sides of the power cylinder from the control valve in the conventional hydraulic steering system, One structure is shown.

The fluid flow control device is composed of a valve housing (1), and a plunger (3) for controlling the flow of fluid by linear sliding therein.

That is, a valve housing 1 having a first port 5 formed to receive hydraulic pressure from the control valve, a second port 7 formed to supply hydraulic pressure from the control valve to the power cylinder, and the first port. A plunger 3 provided in the valve housing 1 so as to be able to linearly slide by hydraulic pressure provided from (5), and a spring 9 for holding the plunger 3 toward the first port 5; A stopper 11 for limiting the movement range toward the first port 5 of the plunger 3 and an end portion facing the first port 5 of the plunger 3 are installed in the valve housing 1. It consists of a spring plate 15 which forms the micro clearance 13 of a fluid with the inner wall surface of the).

The valve housing 1 is formed with a microtube 17 communicating with an oil reservoir in a direction opposite to the first port 5 with respect to the plunger 3, so that the valve housing is operated during operation of the plunger 3. Through the gap between the (1) and the plunger (3) it is possible to discharge the fluid collected in the space where the spring (9) is installed to the oil reservoir, to ensure the operational stability and reliability of the plunger (3) It is for.

Of course, a sealing 19 is installed on the sliding surface between the plunger 3 and the valve housing 1 to prevent leakage of the fluid, and the microtube 17 is in spite of the sealing 19. It is a means for properly discharging the leaked fluid.

The stopper 11 is composed of a stopper end 21 formed in the valve housing 1 and a stopper ring 23 fitted to an outer side of the plunger 3, wherein the plunger 3 is provided with a first port 5. The maximum range that can be moved in the) direction is that the edge of the spring plate 15 integrally installed in the plunger 3 forms the micro clearance 13 as shown in FIG. 5 and the wall surface of the valve housing 1. That's where you can.

Meanwhile, as shown in FIG. 4, the spring plate 15 is formed in an 'S' shape, and a central portion thereof is cocked by the plunger 3 to be integrally coupled to the plunger 3. The plunger 3 has a structure in which a cutout 27 is formed such that both wing portions 25 of the 'S' shaped spring plate 15 are exposed to the hydraulic pressure from the second port 7 side.

That is, the spring plate 15 is supported by the plunger 3 when the hydraulic pressure is provided from the first port 5 side and is not easily deformed. The plunger 3 compresses the spring 9. When the hydraulic pressure acts from the second port 7 side, both wing portions 25 are deformed by the hydraulic pressure and open the flow path.

The fluid flow control device of the hydraulic steering system of the present invention configured as described above is provided with a first port from the control valve when the hydraulic pressure from the power steering pump is supplied from the control valve to the power cylinder by the steering operation of the driver. By the hydraulic pressure supplied to the 5) side, the plunger 3 moves while compressing the spring 9 to communicate the first port 5 with the second port 7, so that the hydraulic pressure is quickly provided to the power cylinder. Allow the steering assistance to be generated as desired.

Of course, the fluid should be returned from the cylinder opposite the power cylinder provided with the hydraulic pressure, and the oil is returned to the control valve through another fluid flow controller installed on the hydraulic pipe connected to the opposite cylinder side with the same configuration as above. It will be sent to the reservoir.

2, the hydraulic pressure of the fluid returned from the power cylinder through the second port 7 is transferred through the cutout 27 of the plunger 3 to the spring plate 15. When acting on both side wings 25 of the, both side wings 25 are deformed by the hydraulic pressure to form a flow path, so that the fluid can be returned to the control valve side.

On the other hand, in the absence of the driver's steering operation as described above, the fluid flows only through the microgap 13, making the piston in the power cylinder difficult to move, which is caused by the reverse input from the tire acting on the steering system. It has the effect of suppressing the kickbacks and the tingle removal.

This is because the hydraulic pressure due to the reverse input from the tire is not large in flow rate and has a repetitive property, and the spring plate mounted on the plunger 3 does not deform well against the reverse input from the tire side as described above. This is because it is deformed so that only a small flow path can be formed, thereby effectively suppressing the action of sudden reverse input.

In addition, as described above, suppression of the sudden action of the reverse input from the tire also suppresses the sudden change in the geometry of the suspension with respect to the reverse input, thereby improving the steering stability of the vehicle.

Therefore, according to the present invention as described above, by allowing the fluid flow control device to impose an appropriate restriction on the flow direction and speed of the fluid in the hydraulic power steering system, while ensuring a smooth power steering operating state and effectively suppress the shimi and kickback The steering stability of the vehicle can be improved.

1 is a view schematically illustrating the main parts of a hydraulic steering system according to the prior art;

2 is a structural diagram showing a fluid flow control device of the hydraulic steering system according to the present invention,

3 is a cross-sectional view taken along line III-III of FIG. 2;

FIG. 4 is a view illustrating point IV of FIG. 2.

<Brief description of symbols for the main parts of the drawings>

One; Valve housing 3; plunger

5; First port 7; 2nd port

9; Spring 11; stopper

13; Microgap 15; Spring plate

17; Microtubules19; Sealing

25; Wings on both sides 27; Incision

Claims (5)

A valve housing having a first port configured to receive hydraulic pressure from the control valve and a second port configured to supply hydraulic pressure from the control valve to the power cylinder; A plunger installed in the valve housing to linearly slide by the hydraulic pressure provided from the first port; A spring which grips the plunger toward the first port; A stopper for limiting the movement range toward the first port of the plunger; A spring plate installed at an end portion of the plunger facing the first port to form a micro clearance of the fluid together with an inner wall surface of the valve housing; Fluid flow control device of the hydraulic steering system, characterized in that configured. The method of claim 1, The valve housing is formed with a micro-tube communicating with the oil reservoir in the opposite direction of the first port with respect to the plunger Fluid flow control device of the hydraulic steering system, characterized in that. The method of claim 1, The stopper includes a stopper end formed in the valve housing and a stopper ring fitted to an outer side of the plunger. Fluid flow control device of the hydraulic steering system, characterized in that. The method of claim 1, A sliding surface is installed on the sliding surface between the plunger and the valve housing to prevent leakage of fluid. Fluid flow control device of the hydraulic steering system, characterized in that. The method of claim 1, The spring plate has a planar shape of an 'S' shape, and a central portion thereof is caulked to the plunger; The plunger is formed with a cutout so that both wing portions of the 'S' shaped spring plate are exposed to the hydraulic pressure from the second port side. Fluid flow control device of the hydraulic steering system, characterized in that.