JPH09226560A - Changeover valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent damage to a sealing member by interlocking a valve with a piston to close the first in let port for interrupting the communication between the first master cylinder and the first pressure chamber and by connecting one end of a connecting rod to a piston including a retaining means axially slidably by a predetermined distance. SOLUTION: As a brake pedal is depressed, brake fluid is fed from the second master cylinder 15 via the second inlet port 16 to the second pressure chamber 8 and moves a piston 6 leftward. In an interlocking relationship with the movement of the piston 6, a connecting rod 21 presses a metal spheric sealing member 19 against a valve seat 18 and surely interrupts the passage 17 communicating the first master cylinder 13 and the first pressure chamber 7. When the sealing member 19 abuts on the seat member 18, the sealing member 19 is not deformed by a pressure acting toward the center of the sealing member 19. Thereafter, the piston 6 is further moved and the brake fluid within the first pressure chamber 7 is pressurized and discharged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a change valve used in a hydraulic brake system for automobiles.

[0002]

2. Description of the Related Art A conventional change valve is an actual open valve 63-
As disclosed in Japanese Unexamined Patent Publication No. 24081, there is a first inlet port connected to a first master cylinder and a second inlet port and an outlet port connected to a second master cylinder, and an inner hole through which these ports communicate with each other. A cylinder body having the above, a first pressure chamber that is axially slidably assembled in the inner hole of the cylinder body, and communicates with the first inlet port and the outlet port in the inner hole, and It is divided into a second pressure chamber that communicates with the second inlet port, and the second
A piston biased to the pressure chamber side and elastically fixed at the original position, and a first inlet port when the piston is arranged in the first pressure chamber and cooperates with the piston and the piston is at the original position. And an outlet valve for communicating between the first inlet and the outlet port when the piston moves a predetermined amount from the original position to the first pressure chamber side. Is provided at a bottom portion of the piston so as to be movably fitted in a recess provided at a tip end portion of the piston on the first pressure chamber side and opening toward the first pressure chamber side so as to be movable in a sliding direction of the piston. A valve body made of an annular elastic member that is attached to and detached from a valve seat provided with a communication hole communicating with the first inlet port to interrupt communication between the first pressure chamber and the first master cylinder;
A spring, which is interposed in a recess of the piston and biases the valve body toward the valve seat, and a spring which is connected to the valve body
A connecting rod that penetrates through a support member arranged on the bottom side of the pressure chamber and a retainer fitted to the tip of the piston so that the retainer is movable by a predetermined amount in the sliding direction of the piston. The connection between the body and the connecting rod is such that the valve body is fitted to the outer periphery of one end of the connecting rod, and the one end surface of the connecting rod facing the valve seat is a flat surface, and the one end surface thereof is The outer peripheral edge of is sharp.

As for the operation of this conventional change valve, in the normal state of the change valve, the valve body of the on-off valve is separated from the valve seat, and the first master cylinder and the first pressure chamber communicate with the inlet port. Brake fluid can communicate with the holes. Therefore, when brake fluid is supplied from the first master cylinder to the change valve, the first
When the brake fluid flows from the outlet port through the pressure chamber to output the braking force, and the supply of the brake fluid from the first master cylinder is released, the braking force is also released.

On the other hand, when the brake fluid is supplied from the second master cylinder to the second pressure chamber via the second inlet port, the piston is pushed toward the first pressure chamber. The valve body comes into contact with the valve seat in conjunction with the operation of the piston, the communication between the first master cylinder and the first pressure chamber is cut off, and the piston is further operated to pressurize the brake fluid in the first pressure chamber. It is then discharged from the outlet port and the braking force is output. When the supply of brake fluid from the second master cylinder is released, the piston is slid toward the initial position by the return spring, and when the piston returns to the initial state, the other end of the connecting rod is locked to the support member. As a result, the valve body is released from the valve seat, the first pressure chamber is communicated with the first master cylinder, and the brake output is also released.

[0005]

However, in the recent hydraulic brake systems for automobiles, there is a tendency that complicated hydraulic devices such as ABS (anti-brake lock system) and TRC (traction control system) are added. When the conventional change valve described above is used in a hydraulic brake system for automobiles to which devices such as ABS are installed, the valve body is connected to the outlet port when the valve body contacts the valve seat and shields the communication hole. ABS
There is a case where the device such as the above is operated and the liquid pressure in the first pressure chamber becomes high due to the operation of the device such as the ABS.

When the liquid pressure in the first pressure chamber becomes high, the high pressure causes a force to urge the annular valve body made of an elastic member inward in the radial direction of the valve body.

When the pressure from the second master cylinder to the piston is released while the hydraulic pressure in the first pressure chamber is high, the piston returns to the initial position, and the connecting rod is also forced to the initial position. , The valve body tries to separate from the valve seat.

Alternatively, when the first pressure chamber is in a high pressure state, the brake fluid is forcibly supplied from the first master cylinder, and the valve element is biased toward the valve seat member by the spring from the valve seat member. The valve body tends to separate from the valve seat by pressing and biasing in the direction of separation against the biasing force of the spring or the brake fluid pressure of the first pressure chamber.

When the valve body is about to separate from the valve seat, the pressure acting on the valve body pushes the valve body inward in the radial direction of the valve body and opposes the valve seat of the connecting rod. The valve body falls inward in the radial direction of the valve disc with the sharp outer peripheral end of the one end face as a fulcrum, and contacts the sharp outer peripheral end of the one end face facing the valve seat of the connecting rod on the inner peripheral side of the valve disc. There is a risk that the contacting points will be damaged.

Further, when the fluid pressure of the first pressure chamber is high and the valve body is collapsed, the brake fluid is again supplied from the second master cylinder and the piston is pushed toward the first pressure chamber side, so that the valve body moves. When it abuts on the valve seat, the valve body is sandwiched between the valve seat and the flat one end face of the connecting rod facing the valve seat, and receives the pressing force by the brake fluid pressure acting on the valve body toward the valve seat. As a result, the valve body may be crushed and damaged.

It is a technical object of the present invention to provide a valve in which the seal member is not damaged.

[0012]

In order to solve the above technical problems, a cylinder body is slidably and liquid-tightly fitted into the cylinder body, and is formed at one end of the cylinder body. A piston forming a first pressure chamber communicating with the outlet port and forming a second pressure chamber on the other end side, and a first inlet port formed in the cylinder body for communicating the first pressure chamber with the first master cylinder. A second inlet port formed in the cylinder body for communicating the second pressure chamber with a second master cylinder; and a second inlet port arranged in the first pressure chamber and interlocked with the operation of the piston, with the first master cylinder. A valve for shutting off communication with the first pressure chamber, the valve coming into contact with and separating from a valve seat member having a communication hole communicating with the first inlet port; A spherical sealing member made of a metal,
A connecting rod that is in contact with the spherical seal member at one end and is slidably connected to the locking member at the other end by a predetermined amount in the axial direction, and a first biasing force that biases the connecting rod toward the valve seat member. And a second urging means for urging the spherical seal member toward one end of the connecting rod.

Preferably, the valve shuts off the communication between the first master cylinder and the first pressure chamber by closing the first inlet port in conjunction with the operation of the piston, and the connecting rod comprises: A change valve, which is slidably connected to the piston including the locking member at its other end in a predetermined amount in the axial direction, is desirable.

Preferably, the urging force of the second urging means is equal to or more than the product of the pressure of the first pressure chamber and the diameter of the communication hole of the valve seat member, and the urging force of the first urging means. Is preferably a change valve that is equal to or greater than the urging force of the second urging means.

In the change valve of the present invention, when the seal member contacts the valve seat member and the communication between the first master cylinder and the first pressure chamber is cut off, the hydraulic circuit communicating with the outlet port has a high pressure. Then, the brake fluid pressure in the first pressure chamber also becomes high, and this high pressure acts on the seal member so as to urge the seal member toward the center of the seal member.

When the pressure applied to the piston from the second master cylinder is released when the pressure in the first pressure chamber is high,
The piston returns to the initial position, and thus the connecting rod is also forced to the initial position, and the seal member is urged by the second urging means and tries to separate from the valve seat member.

Alternatively, when the first pressure chamber is in a high pressure state, the brake fluid is forcibly supplied from the first master cylinder and is urged toward the valve seat member by the first urging means through one end of the connecting rod. The seal member is pressed against the biasing force of the first biasing means or the brake fluid pressure of the first pressure chamber in the direction away from the valve seat member, so that the seal member is pushed by the valve seat member. Try to leave.

When the seal member tries to separate from the valve seat member, the pressure acting on the seal member urges the seal member toward the center of the seal member, but the seal member is made of metal. Therefore, the seal member does not deform.

Further, when the brake fluid is again supplied from the second master cylinder and the piston is pushed toward the first pressure chamber side from the state in which the first pressure chamber is in a high pressure state and the valve is forcibly released. The seal member comes into contact with the valve seat member to disconnect the first master cylinder from the first pressure chamber.
Even when the seal member comes into contact with the valve seat member, the seal member cannot be deformed by the pressure applied to the seal member toward the center of the seal member. To reliably block the communication between the first master cylinder and the first pressure chamber.

[0020]

Embodiments of the present invention will be specifically described below.

As shown in FIG. 1, reference numeral 1 denotes a change valve used in an automobile brake system to which an ABS device is added, and a ring type cup seal is provided in a cylinder body 2 in which a plug 3 is fitted at an opening end. A piston 6 having outer circumferences 4 and 5 is slidably and liquid-tightly fitted, and the first end is provided between one end of the piston 6 and the plug 3.
The pressure chamber 7 has a second pressure chamber 8 formed between the other end of the piston 6 and the closed end of the cylinder body 2.

The first pressure chamber 7 communicates with an actuator 9 forming an ABS device formed in the cylinder body 2, and further with an outlet port 11 communicating with a wheel cylinder 10.

In the plug 3 forming a part of the cylinder body 2, the first pressure chamber 7 is communicated with the first master cylinder 13, and the first inlet port 14 having the filter 25a therein is formed. , In the first pressure chamber 7,
A valve for disconnecting and communicating the return spring 12 of the piston 6 and the first pressure chamber 7 with the first master cylinder via the first inlet port 14 in response to the operation (sliding to the left in FIG. 1) and return of the piston 6. Ten are arranged.

A second pressure chamber 8 communicates with a second master cylinder 15 on the side surface of the cylinder body 2 on the closed end side.
An inlet port 16 is formed.

The plug 3 has an inner hole 3a formed in the axial direction.
And a through hole 3 for communicating the inner hole 3a with the first pressure chamber 7.
b.

The valve 10 has a valve seat member 18 having a communication hole 17 for communicating the first inlet port 14 liquid-tightly inserted into the inner hole 3a of the plug 3 and the first pressure chamber 7.
A metallic spherical seal member 19 capable of coming in and out of contact with the valve member 18, and a connecting rod 20 which is in contact with the seal member 19 at one end and is slidably connected to the piston 6 at a predetermined amount in the axial direction at the other end. , A case 21 that is inserted into the inner hole 3a of the plug 3 to slidably support the connecting rod 20 and has a filter 25b at a portion facing the through hole 3b, and the inner hole 3a of the plug 3 and, by extension, the case 21. Case 2
1, a first spring 22 that is supported in the inner surface of the end wall of the case 21 at one end and urges the connecting rod 20 toward the valve seat member 18 at the other end, and an inner hole 3a of the plug 3.
The second spring 23 is arranged inside the case 21 and is supported by the valve seat member 18 at one end and biases the seal member 19 toward one end of the connecting rod 20 at the other end.

The enlarged portion 20a, which is the other end of the connecting rod 20, is slidably inserted into the axial hole 6a of the piston 6 and is axially moved by a retainer 24 which is a locking member fixed to the piston 6. It is prevented from coming off from the hole 6a.

The urging force of the second spring 23 is set to be equal to or more than the product of the pressure of the first pressure chamber 7 and the diameter of the communication hole 17 of the valve seat member 18, and the urging force of the first spring 22 is the second spring. It is set to be equal to or greater than the biasing force of 23. The biasing force of the return spring 12 causes the piston 6 to move to the initial position (see FIG.
Condition) to open the valve 10 and
It is set to be equal to or more than the difference between the first spring 22 and the second spring 23.

Next, the operation of the change valve 1 of this embodiment will be described. In the normal state of the change valve 1, the seal member 19 is separated from the valve seat member 18, and the first master cylinder 13 and the first pressure chamber 7 are connected to the brake fluid via the inlet port 14 and the communication hole 17. Can communicate with each other. Therefore, when the brake pedal 30a is depressed, the brake fluid is supplied from the first master cylinder 13 to the change valve 1, and the braking force is applied to the wheel cylinder 10 via the first pressure chamber 7, the outlet port 11 and the actuator device 9. Is output and the depression of the brake pedal 30a is released, the braking force on the wheel cylinder 10 is also released.

On the other hand, when the brake pedal 30b is depressed, the brake fluid is supplied from the second master cylinder 15 to the second pressure chamber 8 via the second inlet port 16 and the piston 6 is pushed leftward in FIG. To be done. The connecting rod 21 is moved leftward in FIG. 1 by the first spring 22 in conjunction with the operation of the piston 6, and the connecting rod 21 moves the seal member 19 against the valve seat member 18 against the biasing force of the second spring. Then, the seal member 19 comes into contact with the valve seat member 18 to shield the communication hole 17 in a liquid-tight manner, and disconnects the communication between the first master cylinder 13 and the first pressure chamber 7. Thereafter, when the piston 6 is further operated, the brake fluid in the first pressure chamber 7 is pressurized and discharged from the outlet port 11, and the brake force is output to the wheel cylinder 10 via the actuator device 9.
When the seal member 19 and the valve seat member 18 are brought into contact with each other, since the seal member 19 has a spherical shape, liquid-tight isolation between the first master cylinder 13 and the first pressure chamber 7 is further enhanced.

When the depression of the brake pedal 30b is released, the piston 6 is slid to the right in FIG. 1 by the return spring 12, and when the piston 6 returns to the initial state of FIG. 1, the enlarged portion 20 of the connecting rod 20 is released.
By the engagement of a and the retainer 24, the connecting rod 20 is forced to the position shown in FIG. 1 against the biasing force of the first spring 22, and the seal member 19 is biased by the second spring 23 so that In the disengaged state, the first pressure chamber 7 communicates with the first master cylinder 13, and the brake output to the wheel cylinder 10 is also released.

In the state where the second brake pedal 30b is depressed, that is, when the seal member 19 contacts the valve seat member 18 and the communication hole 17 and the first pressure chamber 7 are shielded, the actuator 9 is closed. When the ABS device is operated, the brake fluid pressure in the first pressure chamber 7 becomes high. In addition, as the brake fluid pressure in the first pressure chamber 7 becomes high, this high pressure acts on the seal member 19.

When the depression of the brake pedal 30b is forcibly released to release the pressure on the piston 6 when the first pressure chamber 7 is in a high pressure state, the piston 6 is moved rightward in FIG. The piston 6 is returned to the return position shown in FIG. 1 by sliding, and the connecting rod 20 is forced to the position shown in FIG. 1 due to the engagement between the enlarged portion 20a of the connecting rod 20 and the retainer 24, and the seal member 19 is moved to the second spring. It is urged by 23 and tries to separate from the valve seat member 18.

Alternatively, when the first pressure chamber 7 is in a high pressure state, the brake pedal 30a is forcibly depressed to supply the brake fluid from the first master cylinder 13, and the first spring 22 is supplied through one end of the connecting rod 20. The seal member 19 biased toward the valve seat member 18 is pressed against the biasing force of the first spring 22 or the brake fluid pressure of the first pressure chamber 7 in the direction away from the valve seat member 18. By energizing, the seal member 19 tends to separate from the valve seat member 18.

When the seal member 19 is about to be separated from the valve seat member 17, the pressure acting on the seal member 19 presses and urges the seal member 19 toward the center of the seal member 19. Since the member 19 is made of metal, the seal member 19 is not deformed.

Further, when the brake pedal 30b is depressed again and the piston 6 is pushed leftward from the state where the first pressure chamber 7 is in the high pressure state and the valve 10 is forcibly released, the seal member 19 is pushed. Comes into contact with the valve seat member 18 to disconnect the first master cylinder 13 from the first pressure chamber 7. Even when the seal member 19 comes into contact with the valve seat member 18, the seal member 19 cannot be deformed by the pressure applied to the seal member 19 toward the center of the seal member 19, and the seal member 19 is not deformed. The member 19 comes into contact with the valve seat member 18 to reliably block the communication between the first master cylinder 13 and the first pressure chamber 7.

As described above, according to the change valve 1 of this embodiment, since the seal member 19 is made of metal, even if a high pressure is applied to the seal member 19, it may be deformed or damaged. It also has a reliable sealing force.

Further, since the seal member 19 has a spherical shape, when the seal member comes into contact with the valve seat member, a greater sealing force is exerted.

Although the present invention has been described based on the above embodiments, the present invention is not limited to only the above embodiments, but includes various embodiments according to the principle of the present invention.

[0040]

As described above, according to the present invention,
Since the seal member is made of metal, there is no fear of being deformed or damaged even when a high pressure is applied to the seal member, and it is possible to reliably exert the sealing force. Furthermore, since the seal member has a spherical shape. It is possible to exert a further sealing force when the seal member comes into contact with the valve seat member,
Therefore, it is possible to provide a change valve without the risk of damage to the seal member.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a change valve 1 according to an embodiment.

[Explanation of symbols]

 1 Change Valve 2 Cylinder Body 6 Piston 7 First Pressure Chamber 8 Second Pressure Chamber 11 Outlet Port 13 First Master Cylinder 14 Inlet Port 15 Second Master Cylinder 16 Second Inlet Port 17 Communication Hole 18 Valve Seat Member 19 Sealing Member 20 Connecting rod 22 1st spring 23 2nd spring

Claims (3)

[Claims] 1. A cylinder body and a first pressure chamber that is slidably and liquid-tightly fitted into the cylinder body and communicates with an outlet port formed in the cylinder body on one end side, and the other end is formed. A piston forming a second pressure chamber on the side, a first inlet port formed on the cylinder body for communicating the first pressure chamber with a first master cylinder, and a second pressure chamber formed on the cylinder body A second inlet port communicating with the two master cylinders; and a valve disposed in the first pressure chamber for shutting off the communication between the first master cylinder and the first pressure chamber in conjunction with the operation of the piston. A valve seat member having a communication hole that communicates with the first inlet port, and a metallic spherical seal member that comes into contact with and separates from the valve seat member.
A connecting rod that is in contact with the spherical seal member at one end and is slidably connected to the locking member at the other end by a predetermined amount in the axial direction, and a first biasing force that biases the connecting rod toward the valve seat member. And a second urging means for urging the spherical sealing member toward one end of the connecting rod. 2. The valve closes the first inlet port in conjunction with the operation of the piston to close the first inlet port.
The communication between the master cylinder and the first pressure chamber is cut off, and the connecting rod is slidably connected to the piston including the locking member at its other end in a predetermined amount in the axial direction. Change valve. 3. The urging force of the second urging means is the first urging force.
The pressure of a pressure chamber and the diameter of the communicating hole of the said valve seat member are more than the product, and the urging | biasing force of the said 1st urging means is more than the urging | biasing force of the said 2nd urging means. Change valve.