JP2958728B2 - Hydraulic pressure control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a valve housing having an input port leading to a hydraulic supply, an output port leading to an actuator, and a release port leading to a reservoir, a forward position for communicating said output port with the input port, and A spool valve element which is slidably fitted to the valve housing and which receives the hydraulic pressure of the output port in the retreating direction, and which is capable of moving between the retreating positions allowing the output port to communicate with the release port; The present invention relates to a hydraulic control device including a linear solenoid that is linked to and connected to a spool valve body so as to be able to provide a hydraulic pressure control.

[0002]

2. Description of the Related Art Conventionally, such an apparatus has been disclosed in, for example,
It is already known from Japanese Patent Publication No. 0-85676.

[0003]

By the way, in the above-mentioned conventional apparatus, a partition partitioning a spring chamber facing the front end of the spool valve element and a reaction force chamber communicating with the outlet port is provided in the valve housing. A reaction force piston that faces the power chamber and coaxially abuts the rear end of the spool valve body with the front end of the spool valve body is slidably fitted to the partition wall. For this reason, the distance between the outlet port and the reaction chamber becomes relatively long, and not only does the overall configuration increase by that much, but also the reaction chamber only opens a passage leading to the outlet port. It is difficult to bleed air from the reaction chamber at the time of filling the working fluid, and air may accumulate in the reaction chamber to adversely affect the operation of the spool.

The present invention has been made in view of the above circumstances, and provides a hydraulic pressure control device that can be made compact and that can prevent air from being accumulated in a reaction chamber. The purpose is to do.

[0005]

According to the present invention, a spool valve body has a first annular recess which communicates with an input port at a forward position thereof, and a spool valve which always communicates with an output port. In the retracted position of the valve body, a second annular concave portion communicating with the release port is provided on the outer periphery, a bottomed sliding hole having an open front end is formed, and a limit member provided in the valve housing limits a forward limit. A regulated reaction force piston is slidably fitted in the slide hole, and is provided at a front portion of a reaction force chamber formed between a rear end of the reaction force piston and a rear closed end of the slide hole. The first annular concave portion is communicated, and the second annular concave portion is communicated with a rear portion of the reaction chamber.

[0006]

An embodiment of the present invention will be described below with reference to the drawings.

Referring to FIG. 1, this hydraulic control device includes a hydraulic control valve 1 and a linear solenoid 2 for operating the hydraulic control valve 1.

The hydraulic pressure control valve 1 has a spool valve body 6 slidably fitted to a housing 3. The housing 3 has a cylindrical valve housing 4 having a stepped bottomed cylindrical cover. 5 and fixed.

[0009] valve housing 4 and the cover 5, an input port 10 leading to the liquid pressure supply source 7, an output port 11 leading to the actuator 8, such as a brake, a first release port 12 ₁ leading to the reservoir 9, the front It is provided at intervals in order from the side to the rear side (from the lower side to the upper side in FIG. 1). The spool valve element 6 forms a spring chamber 13 between the closed end of the cover 5, that is, the front end of the housing 3, and is slidably fitted to the valve housing 4. It communicates with the reservoir 9 through the release port 12 _2. Moreover, on the outer surface of the spool valve element 6, a first annular recess 14 that can communicate with the input port 10 is provided.
Always communicates with the output port 11 and
The second annular recess may communicates with the first release port 12 ₁ 1
5 are provided at intervals in the axial direction.

In the front half of the spool valve body 6, a bottomed sliding hole 16 having a front end opened and a rear end closed is coaxially formed. A reaction piston 18 forming a reaction chamber 17 between the hole 16 and the rear closed end is slidably fitted. Moreover, the first annular recess 14
Is communicated with the front of the reaction force chamber 17 through a communication hole 19 formed in the spool valve element 6 along the radial direction, and the second annular concave portion 15 is connected to the spool valve element 6 along the radial direction. The first and second annular concave portions 14 and 15 are connected to each other through the reaction force chamber 17 through the communication hole 20 formed therein and communicated with the rear portion of the reaction force chamber 17.

A cap 21 is fitted to the front end of the reaction force piston 18 projecting from the front end of the spool valve body 6. A retaining ring 22 is fitted on the inner surface of the front end of the valve housing 4, and a retainer 23 as a regulating member capable of receiving the cap 21 is locked to the retaining ring 22. In addition, a return spring 24 is contracted between the retainer 23 and the cap 21. Therefore, the spool valve element 6
When no hydraulic pressure is acting on the reaction force chamber 17, the return spring 2
4, the hydraulic pressure acts on the reaction force chamber 17, and in a state where the reaction force piston 18 advances to the forward limit where the cap 21 abuts the retainer 23, the reaction force chamber The hydraulic pressure of the output port 11 is urged in the backward direction by the hydraulic pressure of the output port 11. On the other hand, since the forward thrust acts on the spool valve element 6 from the linear solenoid 2, the spool valve element 6 moves in the front-rear direction so as to balance those forces. a retracted position closes the port 10 via the second annular recess 15 communicating between the output port 11 and the first release port 12 _1, the input port 10 first annular recess 14
The output port 11 is connected to the input port 1
With communicating to 0 moves the valve housing 4 between a forward position to cut off from the first release port 12 _1.

The linear solenoid 2 is coaxially connected to the rear end of the housing 3 in the hydraulic pressure control valve 1, and the rear end of the cover 5 is brought into contact with the rear end of the valve housing 4 in the housing 3. A fixed core 26 screwed into the opening, and a yoke 27 disposed opposite to the fixed core 26
A movable core 28 disposed between the fixed core 26 and the yoke 27; and a drive rod 29 integrally and coaxially connected to the movable core 28 and penetrating the fixed core 26 movably.
And a coil 30 for exerting an electromagnetic force for attracting the movable core 28 to the fixed core 26 side.

The fixed core 26 and the yoke 27 have cylindrical projections 26 for guiding the movable core 28 in the axial direction.
The coils 30a and 27a are coaxially opposed and protruded at an interval from each other, and the coil 30 is disposed so as to surround the protrusions 26a and 27a. Further, the fixed core 26 and the yoke 27 are mutually connected by a cylindrical tubular body 31 surrounding the coil 30.

The rear end of the drive rod 29 is supported by the yoke 27 via a bearing 32 so as to be movable in the axial direction.
A bearing 33 for guiding the drive rod 29 in the axial direction is interposed between the fixed core 9 and the fixed core 26.

The distal end of the drive rod 29 is coaxially abutted on the rear end of the spool valve element 6 in the hydraulic pressure control valve 1. The movable core 28 integral with the drive rod 29 has a coil 30 in a demagnetized state. , The spring is biased in a direction away from the fixed core 26 by the spring force of the return spring 24 interposed between the front end of the spool valve element 6 and the retainer 23.

Such a linear solenoid 2 exerts a thrust in the forward direction in accordance with the amount of power applied to the coil 30. When the coil 30 is excited, the drive rod 29 moves the spool valve 6 in the forward direction. Of thrust is given.

When a forward thrust is applied to the spool valve element 6 from the linear solenoid 2, the spool valve element 6
Is the first release port 12 ₁ shielded from the second annular recess 15 i.e. reaction chamber 17, then advanced to the position for communicating the input port 10 to the first annular recess 14, that is, the reaction force chamber 17, reaction chamber 17 The reaction force piston 18 advances with respect to the spool valve element 6 in response to the hydraulic pressure from the hydraulic pressure supply source 7 acting on the cap 2 at the front end of the reaction force piston 18.
1 is received by the retainer 23. In the state where the reaction force piston 18 is received by the retainer 23 in this manner, the thrust in the forward direction given by the linear solenoid 2 and the reaction force chamber 1
The spool valve element 6 moves in the axial direction in accordance with the magnitude relationship with the retraction force due to the hydraulic pressure of the hydraulic pressure 7, and the hydraulic pressure from the hydraulic pressure supply source 7 acts on the output port 11, When the hydraulic pressure is released, the hydraulic pressure from the hydraulic pressure source 7 is output from the output port 11 while being controlled in proportion to the exciting current of the linear solenoid 2.

Next, the operation of this embodiment will be described. The reaction piston 18 is slidably fitted in the slide hole 16 at the front part of the spool valve body 6 so that the advance limit is restricted by the retainer 23. A reaction force chamber 17 is formed between the rear end of the sliding hole 16 and the rear closed end of the sliding hole 16.
Since it communicates with the output port 11 through the 0 and the second annular recess 15, it is not necessary to provide a passage through the reaction force chamber 17 and the output port 11 in the valve housing 4,
The hydraulic pressure control valve 1 can be made more compact than a conventional one which requires a space for forming a reaction force chamber in addition to the length required for sliding of the spool 6.

Moreover, the input port 10 is connected to the first annular recess 14.
And the front part of the reaction force chamber 17 through the communication hole 19,
The rear portion of the reaction force chamber 17 is provided with a communication hole 20 and a second annular recess 15.
Communicates with the output port 11 via, the rear end of the second annular recess 15 can communicate with the first release port 12 _1, when filled with hydraulic fluid from the input port 10 side, outputs the working fluid port 11 and smoothly it can be supplied to the first release port 12 ₁ side, never accumulate air occurs in the reaction chamber 17, thus the reaction force due to the hydraulic pressure corresponding to the output of the output port 11 the spool valve body 6 And a reliable operation can be realized.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments, and various design changes can be made without departing from the present invention described in the appended claims. It is possible to do.

[0021]

As described above, according to the present invention, the spool valve element has the first annular concave portion communicating with the input port at the forward position, and the release port at the retract position of the spool valve element always communicating with the output port. A second annular recess is also provided on the outer periphery, and a bottomed sliding hole with an open front end is drilled, and a reaction force piston whose forward limit is regulated by a regulating member provided in the valve housing is provided. A first annular recess is slidably fitted in the sliding hole, and a first annular recess communicates with a front portion of a reaction force chamber formed between a rear end of the reaction force piston and a rear closed end of the slide hole, Since the second annular concave portion communicates with the rear portion of the reaction force chamber, it is not necessary to provide an extra space for forming the reaction force chamber, so that the overall configuration can be made compact and the reaction force from the input port can be reduced. Output port and release via chamber To prevent the reservoir air is generated in the reaction chamber by forming a channel through the over preparative it is possible to realize reliable actuation.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of one embodiment of the present invention.

[Explanation of symbols]

2 Linear solenoid 4 Valve housing 6 Spool valve element 7 Hydraulic pressure supply source 8 Actuator 9 Reservoir 10 Input port 11 Output port 12 ₁ Release port 14 First annular recess 15 Second annular recess 16 Sliding hole 17 Reaction force chamber 18 Reaction force Piston 23 Retainer as regulating member

Claims (1)

(57) [Claims] _1. A valve housing having an input port (10) leading to a hydraulic supply (7), an output port (11) leading to an actuator (8), and a release port (12 ₁ ) leading to a reservoir (9). 4) and a forward position where the output port (11) communicates with the input port (10), and the output port (11) is opened to the release port (12).
_A spool valve element (6) that is slidably fitted to the valve housing (4) and that receives the hydraulic pressure of the output port (11) in the reverse direction, allowing movement between the retracted positions communicating with 1). In a hydraulic pressure control device having a linear solenoid (2) that is capable of applying a thrust in the forward direction and is interlocked with and connected to the spool valve body (6), the spool valve body (6) has a forward position. A first annular recess (14) communicating with the input port (10), and a second annular recess (15) which always communicates with the output port (11) and also communicates with the release port (12 ₁ ) at the retracted position of the spool valve element (6). ) Are provided on the outer periphery, a bottomed sliding hole (16) having an open front end is formed, and a reaction force whose forward end is regulated by a regulating member (23) provided in the valve housing (4). The piston (18) is Slidably fitted in Doana (16), wherein the rear end of the reaction force piston (18) sliding hole (1
6) A first annular concave portion (14) is communicated with a front portion of a reaction force chamber (17) formed between the reaction force chamber (1) and the reaction force chamber (1).
7) The hydraulic pressure control device, wherein a second annular concave portion (15) communicates with a rear portion.