JPH0427733Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to an auto-stop valve for maintaining brake fluid pressure when a vehicle is stopped.

[Conventional technology]

An auto-stop valve for maintaining brake fluid pressure when the vehicle is stopped is described in Japanese Patent Laid-Open No. 11953/1983, which was previously filed by the applicant.
The auto-stop valve for vehicles described in this publication has an input chamber 2 connected to a master cylinder M/C and an output chamber 3 connected to a wheel cylinder W/C, as shown in FIG. 14, and a valve opening rod 15 that presses the valve body 25 that opens and closes the flow passage 14 in the opening direction, and a set spring 16 that presses the valve opening rod 15 in the opening direction,
A push rod 26 is provided to press the valve body 25 against the valve seat 11, and the push rod 26 is inserted into the fixed core 28, and the rear part of the push rod 26 is fitted into a fitting hole 40 formed in the armature 29, so that the armature This is an auto stop valve for a vehicle which is formed so as to press a push rod 26 at 29.

This auto stop valve for vehicles stops the master cylinder M/M when the brake pedal is depressed.
The hydraulic pressure of C is transmitted to the wheel cylinder W/C via the flow path 14, and when the vehicle stops, the coil 3
2, the armature 29 moves toward the valve body 25, the push rod 26 presses the valve body 25, brings the valve body 25 into pressure contact with the valve seat 11, and the flow path 14
Even if the brake pedal is closed and the brake pedal is no longer depressed, the hydraulic pressure in the wheel cylinder W/C is maintained.

[The problem that the idea attempts to solve]

In auto stop valves for vehicles, if the hydraulic pressure contained and held in the wheel cylinder W/C is made higher than necessary, flow velocity noise may occur when the brake fluid returns to the master cylinder M/C when the hydraulic pressure is released, and , disadvantages such as a decrease in the strength of the master cylinder M/C due to impact pressure occur.

In the conventional auto-stop valve for vehicles shown in FIG. 3, the hydraulic pressure of the brake fluid contained and held in the wheel cylinder W/C is determined by the thrust of the coil 32 that presses the valve body 25 against the valve seat 11 with the push rod 26. is determined, and the thrust of the coil 32 is
It is determined by the distance between the rear end surface of the fixed core 28 and the front surface of the armature 29 when the armature 29 is operated and the valve body 25 is pressed against the valve seat 11, but there may be variations depending on the dimensional tolerance of the parts. Therefore, it is difficult to set it constant.

This invention was made in view of the above matters,
A technical problem is to easily set the hydraulic pressure of brake fluid contained and held in a wheel cylinder W/C.

[Means to solve the problem]

In the present invention, a valve seat body 10 is slidably fitted into a cylinder 1, and a hold spring 12 is provided to press the valve seat body 10 toward a valve body 25. Between the 10 seats,
a valve opening rod 15 that presses the valve body 25 in the opening direction;
A set spring 16 is provided to press the valve opening rod 15 in the opening direction, and the input chamber 2 on the front side of the valve seat 11 is connected to the master cylinder M/C, and the output chamber 3 connected to the flow path 14 is connected to the wheel cylinder W/C.
A push rod 26 is connected to C and presses the valve body 25 against the valve seat 11. The push rod 26 is inserted into the fixed core 28 and has its rear end pressed against the front part of the armature 29. It is a top valve.

[Effect]

In the present invention, when not in operation, the hold spring 12 is extended and the valve seat body 10 is moved toward the valve body 25 side. And set spring 16
extends and presses the valve opening rod 15, and the valve opening rod 15
presses the valve body 25, separates the valve body 25 from the valve seat 11, and connects the flow path 14. The valve body 25 presses the push rod 26, and the push rod 26 presses the front surface of the armature 29, causing the armature 29 to move backward, and the gap between the fixed core 28 and the armature 29 widens.

When you press the brake pedal (not shown),
The brake fluid in the master cylinder M/C is introduced into the wheel cylinder W/C through the flow path 14, and the wheels are braked.

When a current flows through the coil 32 while braking the wheels,
The armature 29 moves to the fixed core 28 side, presses the push rod 26, presses the valve body 25 against the valve seat 11, and then stops pressing the brake pedal, even if the hydraulic pressure in the master cylinder M/C disappears. , the flow path 14 is closed, and the hydraulic pressure in the wheel cylinder W/C is sealed and maintained.

At this time, the hydraulic pressure of the wheel cylinder W/C is
If the hydraulic pressure is higher than the set value, the hydraulic pressure in the output chamber 3 causes the valve seat body 10 to compress the hold spring 12 and move away from the valve body 25 . That is, the force acting in the direction in which the valve seat body 10 compresses the hold spring 12 is the product of the cross-sectional area of the valve seat body 10 and the hydraulic pressure in the output chamber 3, and presses the valve seat body 10 in the opposite direction. Since the force is the product of the difference between the cross-sectional area of the valve seat body 10 and the valve body pressure receiving area 24 and the hydraulic pressure in the output chamber 3, the higher the hydraulic pressure in the output chamber 3, the more the valve seat body 1
0 means that the valve body 2 receives a force in the direction away from the valve body 25.
Stay away from 5. Therefore, the brake fluid in the wheel cylinder W/C introduced above the set fluid pressure is
It flows out from between the valve seat 11 and the valve body 25 to the master cylinder M/C side, and the hydraulic pressure of the wheel cylinder W/C is maintained at the set hydraulic pressure.

In addition, the valve body 25 is connected to the valve seat 1 by the push rod 26.
1, the push rod 26 is pressed by the armature 29, and the wheel cylinder W/C
When the hydraulic pressure is higher than the set hydraulic pressure, the valve body 25 is pushed by the hydraulic pressure in the output chamber 3, moves away from the valve seat 11 against the pressing force of the armature 29, and the brake fluid with the set hydraulic pressure or higher is mastered. This will flow out to the cylinder M/C side.

〔Example〕

1 and 2 show an auto-stop valve for a vehicle according to an embodiment of the present invention. Inside the cylinder 1, which is formed by a small-diameter cylinder 1a and a large-diameter cylinder 1b, is a bottomed cylindrical valve. A valve seat body 10 is slidably fitted into the opening of the valve seat body 10, and a valve seat 11 formed as a flanged cylindrical body is fitted and fixed in the opening of the valve seat body 10. A seal cup 17 that contacts the small-diameter cylinder 1a and a seal ring 18 that contacts the large-diameter cylinder 1b are fitted on the outside, and a hold spring 12 that presses the valve seat body 10 toward the valve body 25 is attached to the valve seat body 10. It is provided between the plugs 13. A flow path 14 is provided within the valve seat 11 and the valve seat body 10, and a valve opening that presses the valve body 25 in the opening direction is provided between the valve body 25 that opens and closes the flow passage 14 and the valve seat body 10. A rod 15 and a set spring 16 for pressing the valve opening rod 15 in the opening direction are provided.

The input chamber 2 in front of the valve seat 11 is connected to the master cylinder M/C, and the output chamber 3 connected to the flow path 14 is connected to the wheel cylinder W/C.

A push rod 26 for pressing the valve body 25 against the valve seat 11 is provided on the opposite side of the valve opening rod 15, and the push rod 26 is connected to the fixed core 28.
A flange 27 is formed at the rear end of the armature 29, and the flange 27 is pressed against the front surface of the armature 29, and an adjustment screw 30 and a lock nut 31 are used to restrict the retreating position of the armature 29. , and a coil 32 for operating the armature 29, and a seal cup 17 and a seal ring 18 are inserted at the end of the fixed core 28.

In the above embodiment, the cylinder 1 is a small diameter cylinder 1.
a and the large-diameter cylinder 1b, there is a pressure-receiving area for the hydraulic pressure that acts in a direction that moves the valve seat body 10 away from the valve body 25, and a pressure-receiving area for the liquid pressure that acts in a direction that presses the valve seat body 10 against the valve body 25. The difference between the pressure and the pressure-receiving area becomes even larger.

The flange 27 provided on the push rod 26 prevents the front surface of the armature 29 from coming into close contact with the rear end surface of the fixed core 28 when the valve seat body 10 moves largely away from the valve body 25.
Therefore, the current in the coil 32 is cut off, and the flow path 1
4, the armature 29 is in close contact with the fixed core 28, preventing backward movement and preventing pressure reduction in the wheel cylinder W/C.

Furthermore, since the push rod 26 contacts the armature 29 at the flange 27, the armature 29
The length from the to the tip of the push rod 26 can be easily and accurately adjusted.

[Effect of idea]

In the auto-stop valve for vehicles of the present invention, the armature 29 operates, the push rod 26 presses the valve body 25 against the valve seat 11, closes the flow path 14, and transfers brake fluid pressure to the wheel cylinder. When the valve seat body 10 is sealed and held in the W/C, the pressure receiving area of the hydraulic pressure that acts in a direction that moves the valve seat body 10 away from the valve body 25 is larger than the pressure receiving area of the hydraulic pressure that acts in a direction that presses the valve seat body 10 against the valve body 25. Therefore, if the hydraulic pressure is higher than the set hydraulic pressure, the valve seat body 10
moves to discharge the pressure fluid and maintain the hydraulic pressure at the set hydraulic pressure, and since the set hydraulic pressure is determined by the strength of the hold spring 12, the set hydraulic pressure can be accurately and easily set.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention, FIG. 2 is an enlarged sectional view of a part thereof, and FIG. 3 is a sectional view of a conventional example. DESCRIPTION OF SYMBOLS 1...Cylinder, 2...Input chamber, 3...Output chamber, 10...Valve seat body, 11...Valve seat, 12...Hold spring, 14...Flow passage, 15...Valve opening rod, 16 ... Set spring, 25 ... Valve body, 26 ... Push rod, 28 ... Fixed core, 29 ... Armature.

Claims (1)

[Scope of utility model registration request] The valve seat body 10 is slidably fitted into the cylinder 1, and a hold spring 12 is provided to press the valve seat body 10 toward the valve body 25, and between the valve body 25 and the valve seat body 10, which open and close the flow passage 14. includes a valve opening rod 15 that presses the valve body 25 in the opening direction, and a valve opening rod 1 that presses the valve body 25 in the opening direction.
A set spring 16 is provided to press the valve 5 in the opening direction, and the input chamber 2 on the front side of the valve seat 11 is connected to the master cylinder M/C, and the output chamber 3 connected to the flow passage 14 is connected to the wheel cylinder W/C. ,
A push rod 26 is provided for pressing the valve body 25 against the valve seat 11, and the push rod 26 is inserted into the fixed core 28, and the rear end of the push rod 26 is pressed against the front part of the armature 29. valve.