JPH0310123Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a control valve, for example, a control valve used as a control valve of a power steering device for a vehicle.

(Prior Art) As conventional control valves of this type, those shown in FIGS. 5 and 6, for example, are known.
In FIG. 5, reference numeral 1 denotes a torsion bar connected to a stub shaft (not shown) to which rotation of the steering wheel is transmitted, and this torsion bar 1 is connected to an operating shaft 1a (which may be a pinion or a worm), The rotation of the shaft is transmitted to the actuating shaft 1a. Also 2a,
2b is a stub shaft pin which is fixed to the stub shaft and rotates at the same time. On the other hand, 3a,
3b is a spool housing press-fitted into the operating shaft 1a, and the spool housings 3a, 3
Spool valves 4a and 4b are slidably inserted into the holes b. The spool valves 4a, 4b have holes 5a, 5b that are slightly larger in diameter than the stub shafts 2a, 2b, and the stub shaft pins 2a, 2b are inserted into the holes 5a, 5b. When the steering wheel rotates, the rotation is transmitted to the stub shaft pins 2a, 2b, and the spool valves 4a, 4b are rotated by the amount of torsion of the torsion bar 1.
move in the axial direction. Also, spool valve 4
Variable orifices 6a, 6b, 6c, 6d are formed between a, 4b and the spool housings 3a, 3b. Variable orifice 6a, 6b, 6
c, 6d are these orifices 6a, 6b, 6c, 6d by sliding of spool valves 4a, 4b.
Controls the amount of hydraulic fluid that passes through. That is, these spool valves 4a and 4b constitute a control valve that switches the hydraulic oil to the power cylinder. Therefore, by moving the spool valves 4a, 4b, the high pressure hydraulic oil supplied from the pump is transferred to the variable orifices 6a, 6b, 6.
A predetermined flow rate is supplied to each working chamber of the power cylinder through c and 6d to assist rotation of the sector shaft (in the case of a recirculating type). When the sector shaft is rotated, the steering link is rotated in a predetermined direction via the pitman arm, thereby performing a turning operation of the vehicle.

On the other hand, retainer valves 7a and 7b are attached to the side ends of the spool housings 3a and 3b.
damper chambers 8a, 8b are defined by a, 7b and spool valves 4a, 4b. The retainer valves 7a, 7b have orifice holes 9a, 9b.
The hydraulic oil in the damper chambers 8a, 8b flows in and out through the orifice holes 9a, 9b. The spool valves 4a, 4b slide smoothly at a constant speed due to the damper action of the damper chambers 8a, 8b. For details, see stub shaft pin 2.
Damper chambers 8a, 8b are provided in order to prevent pulsation of hydraulic pressure that occurs when the spool valves 4a, 4b slide due to machining errors between the spool valves 4a, 2b and the holes 5a, 5b.

Further, in FIG. 6, the retainer valve 10
A substantially cylindrical body 1 such as a worm or pinion
A damper chamber 15 is defined by the retainer valve 10, the spool housing 13, and the spool valve 14.

(Problem to be solved by the invention) However, in such a conventional control valve, in order for the spool valves 4a and 4b to slide smoothly at a constant speed, the orifice holes 9a and 9b are
It is necessary to strictly control the diameter of the
It is necessary to prevent hydraulic oil from leaking between the retainer valves 7a, 7b and the spool housings 3a, 3b. For this reason, retainer valve 7
The contact surfaces between a, 7b and the spool housings 3a, 3b had to be strictly controlled by increasing their surface roughness.

Further, in the conventional control valve shown in FIG. 6, the dimensions of the hole into which the retainer valve 10 is press-fitted, that is, the approximately cylindrical main body 11, must be strictly controlled.

Therefore, there has been a problem in that the cost of the control valve increases due to these controls.

(Means for Solving the Problems) In order to solve these problems, the control valve according to the present invention includes a spool valve that is slidably inserted into a spool housing, and a stepped portion formed on the outer periphery. and a retainer valve in which one end of the spool housing is sealed by the stepped portion and an orifice hole is formed, and a damper chamber is defined by the spool housing, the retainer valve, and the spool valve. In the control valve, an annular washer is sandwiched between one end of the spool housing and the stepped bottom of the retainer valve,
A seal accommodating chamber is formed between the inner periphery of the washer, the bottom of the step, the outer periphery of the step, and one end of the spool housing, and a seal member is interposed in the seal accommodating chamber.

(Function) In the device having such a configuration, the hydraulic oil in the damper chamber does not leak from between the spool housing and the retainer valve because a sealing member is interposed between the spool housing and the retainer valve. . Therefore, the spool valve slides smoothly at a constant speed due to the damper action of the damper chamber.

Further, an annular washer is sandwiched between one end of the housing and the bottom of the step of the retainer valve, and a seal storage chamber is provided between the inner periphery of the washer, the bottom of the step, the outer periphery of the step, and one end of the spool housing. Since the seal member is interposed in the seal housing chamber, the surface roughness of the contact surface between the retainer valve and the spool housing can be increased and strictly controlled, and a hole for press fitting and a substantially cylindrical main body are provided. There is no need to strictly control the dimensions of the

(Example) Hereinafter, an example of this invention will be described based on the drawings. FIG. 1 is a diagram showing an embodiment in which this invention is applied to a power steering system for a vehicle. Note that the same components as in the conventional example are given the same reference numerals, and the explanation thereof will be omitted.

First, the configuration will be explained. In FIG. 1, a stepped portion is formed on the outer periphery of the retainer valves 7a, 7b, and one end side of the spool housings 3a, 3b is sealed by this stepped portion. That is, this step bottom and the spool housings 3a, 3
Annular washers 22a, 22b having a predetermined thickness are sandwiched between one end of the washers 22a, 22b, and the inner periphery of the washers 22a, 22b, the bottom of the step, the outer periphery of the step, and one end of the spool housing 3a, 3b. A seal accommodating chamber is defined between the spool housings 3a and 3b, and O-rings 21a and 21b are interposed in this seal accommodating chamber to seal one end side of the spool housings 3a and 3b. O-rings 21a, 21
b is juxtaposed with washers 22a and 22b,
By appropriately selecting the thickness of the washers 22a, 22b, an appropriate clearance can be provided (the O-rings 21a, 21b are arranged inside the annular washers 22a, 22b as shown in FIG. (attached to the periphery). Therefore, the O-rings 21a, 21b completely seal between the spool housings 3a, 3b and the retainer valves 7a, 7b. In addition, the spool housings 3a, 3
Since an annular washer is sandwiched between one end of the retainer valve 22a and the stepped bottom of the retainer valves 7a and 7b, a part of the sealing chamber is formed by the washer 22a and 22b. As a result, there is no need to strictly control the contact surfaces between the spool housings 3a, 3b and the retainer valves 7a, 7b. Furthermore, the diameters of the orifice holes 9a and 9b can be easily controlled. Furthermore, the damper action of the damper chambers 8a, 8b is improved. On the other hand, the retainer valves 7a and 7b are attached to the fixing plate 2.
3 to the spool housings 3a, 3b by bolts 24.

Next, the effect will be explained.

When the steering wheel is rotated, the rotation causes the stub shaft pins 2a, 2b to rotate in opposite directions about the torsion bar 1 by the amount of torsion deformation of the torsion bar 1, and as a result, the spool valves 4a, 4b are moved in their axial directions. let At this time, an O-ring 2 is inserted between the spool housings 3a, 3b and the retainer valves 7a, 7b.
Since 1a and 21b are interposed, the hydraulic oil in the damper chambers 8a and 8b will not leak from between them. Therefore, the hydraulic oil in the damper chambers 8a, 8b gradually flows in and out from the orifice holes 9a, 9b (the orifice holes 9a, 9b open into the high pressure oil chamber from the pump), and the damper chambers 8a, 8b Completely performs its damping action. Therefore, the stub shaft pins 2a, 2b are always engaged in contact with one end of the holes 5a, 5b, and the spool valves 4a, 4b are smoothly moved at a constant speed to the spool housings 3a, 3b.
Slide inside. As a result, pulsation does not occur in the hydraulic oil, and the power steering device does not vibrate, resulting in a good steering feel. On the other hand, these spool valves 4a, 4
Variable orifices 6a, 6b, 6 by sliding b
The amount of hydraulic oil passing through c and 6d is controlled. High-pressure hydraulic oil supplied from the pump flows into the steering gear box (each working chamber of the power cylinder) through variable orifices 6a, 6b, 6c, and 6d, and assists rotation of the sector shaft. When the sector shaft is rotated, the steering link is rotated in a predetermined direction via the pitman arm, thereby performing a turning operation of the vehicle.

FIG. 3 shows another embodiment of the invention. This embodiment is of a type in which a portion of the retainer valve 7a is press-fitted into the end of the spool hole of the spool housing 3a. O-ring 2 which is a sealing member
1a and washer 22a are interposed between the contact surfaces of spool housing 3a and retainer valve 7a. In this case, as shown in FIG. 4, the O-ring 21a and the washer 22a may be formed separately. In addition, in the above embodiments, the sealing member 21 was juxtaposed or bonded to the inside of the washer 22.
The sealing member 21 may be juxtaposed or bonded to the outside of the washer 22.

Further, the washers 22a and 22b are not interposed between the spool housings 3a and 3b and the retainer valves 7a and 7b,
A washer portion may be provided on one of the contact surfaces of the retainer valves 7a, 7b and the retainer valves 7a, 7b (that is, a groove for inserting an O-ring may be provided in one of the retainer valves 7a, 7b or the spool housings 3a, 3b). ). In each of the above embodiments, the control valve is applied to a power steering device of a vehicle, but the present invention is not limited to this and can be applied to other devices.

(Effects of the invention) As is clear from the above explanation, according to this invention, an annular washer is sandwiched between one end of the spool housing and the stepped bottom of the retainer valve,
A seal storage chamber is formed between the inner periphery of the washer, the bottom of the step, the outer periphery of the step, and one end of the spool housing, and a seal member is interposed in the seal storage chamber, so that the space is completely sealed. Strict control such as increasing the surface roughness of the contact surface between the retainer valve and the spool housing becomes unnecessary. Also,
Since the space between the spool housing and the retainer valve is completely sealed, the damper effect of the damper chamber is improved and the diameter of the orifice hole can be easily controlled. Therefore, the cost of the control valve according to this invention can be reduced.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing one embodiment of the control valve according to this invention. FIG. 2 is a perspective view showing a washer and a seal member used in this control valve. FIG. 3 is a sectional view of a main part showing another embodiment of the present invention, and FIG. 4 is an exploded perspective view showing the seal member and washer. FIG. 5 is a sectional view showing a conventional control valve, and FIG. 6 is a sectional view showing another type of conventional control valve. 3a, 3b...Spool housing, 4a, 4
b...Spool valve, 5a, 5b...hole, 7
a, 7b...retainer valve, 8a, 8b...damper chamber, 9a, 9b...orifice hole, 21a,
21b, 23...Sealing material, 22a, 22b, 2
4...Watsiya.

Claims (1)

[Scope of utility model registration request] a spool valve that is slidably fitted into a spool housing; and a retainer valve that has a step formed on its outer periphery, seals one end of the spool housing with the step, and has an orifice hole formed therein. In this control valve, a damper chamber is defined by the spool housing, the retainer valve, and the spool valve. forming a seal storage chamber between the inner periphery of the washer, the bottom of the step, the outer periphery of the step and one end of the spool housing;
A control valve characterized in that a seal member is interposed in the seal housing chamber.