JPH0353952Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a brake fluid pressure holding device that maintains a vehicle in a braking state when the vehicle is stopped by operating a brake pedal.

(Prior Art) Hydraulic brakes are used as brakes for braking ordinary vehicles. This type of brake generates hydraulic pressure in the master cylinder by depressing the brake pedal, which operates a piston in the wheel cylinder attached to the brake drum, which in turn activates the brake shoe connected to this piston. It drives and brakes the wheels. In the case of brakes for such vehicles, the braking state is released when the brake pedal is released, so conventionally, as shown in Japanese Patent Application Laid-Open No. 11953/1983, the braking state is released when the brake pedal is released. If you stop the vehicle by pressing the brake pedal, even if you release the brake pedal,
Techniques have been developed that maintain hydraulic pressure in the wheel cylinders to keep the wheels in a braked state.

When performing a braking operation, it may be necessary to further apply braking force when the brake pedal is depressed to stop the vehicle. For example, in the case of an automatic car, when the vehicle is in the drive range, such as while waiting at a traffic light, the air conditioner for cooling the vehicle interior begins to operate, and the clutch is turned on to drive the compressor that drives the cooling cycle. In this case, the idling speed will be set higher in response to the operation of the compressor. Then, due to the increased engine speed, the vehicle receives a propulsive force in the direction in which it starts moving forward, so it is necessary to further increase the braking force. For example, even in the case of a manual car, the car may start to move due to car vibrations or external shocks, and in this case, it is necessary to press the brake pedal additionally to further increase the braking force. be. Furthermore, for example, when the vehicle is stopped on an uphill slope, if the brake pedal is depressed only with the braking force necessary for braking the vehicle, the braking force will not be enough, and in order to prevent the vehicle from moving backward, You may also press the brake pedal harder. Considering such a case, if the supply of liquid from the master cylinder to the wheel cylinders is cut off while the vehicle is stopped, the vehicle cannot be stopped reliably.

Therefore, in the above conventional technology, even if the brake fluid pressure holding device is activated and the vehicle is stopped, when the brake pedal is depressed again,
This allows liquid to flow from the master cylinder to the wheel cylinder.

(Problem to be solved by the invention) For this purpose, in the conventional brake fluid pressure holding device, a valve body is provided in the flow path that communicates the master cylinder and the wheel cylinder to open and close this flow path. In addition to the valve body, a one-way flow means is provided to allow liquid to flow from the master cylinder to the wheel cylinder even when the valve body closes the flow path (for example, as described in Japanese Patent Publication No. 51-26171). Disclosed “auxiliary passage” and “return check O-ring”
reference).

However, when a one-way flow means is formed by providing an auxiliary passage that bypasses this flow path in addition to the conventional valve body consisting of a ball, the valve body and the valve seat that come into contact with this valve body are It is necessary to provide auxiliary passages and check valve means to match the parts. Therefore, such a conventional brake fluid pressure holding device has a problem in that the device is complicated due to the large number of parts, and it is not easy to control the accuracy of each part.

Further, by providing the auxiliary passage, there is a problem in that the sealing performance between the valve body made of a ball and the valve seat member is insufficient, and liquid leakage may occur.

The object of the present invention is to provide a brake fluid pressure retaining device with a simple structure, and to achieve reliable sealing with this simple structure.

(Means for Solving the Problems) The present invention to achieve the above object connects the first port to which the pipe on the master cylinder side is connected and the second port to which the pipe on the wheel cylinder side is connected to the main body of the device. forming a flow path in the device main body that communicates the respective ports with each other, and providing a valve body in the device main body that opens and closes the flow path, and contacting the valve body to open the flow path. A stopper having an elastic force applied in an opening direction is provided on the device main body, and a push rod that contacts the valve body and operates in a direction to close the valve body by a solenoid against the elastic force of the stopper. is provided in the device main body, and closes the flow passage by pressing and holding the valve body at the bottom dead center of the stopper with the push rod, and a valve seat member that contacts the valve body and closes the flow passage. The brake fluid pressure holding device is configured to be movable so as to separate from the valve body and open the flow path when the pressure of the liquid reaching the flow path from the first port increases.

(Operation) When the flow path is closed by energizing the solenoid and bringing the valve element into contact with the valve seat member using the push rod, the liquid in the wheel cylinder will flow into the master cylinder due to the action of the valve element. It will not return and the braking state will be maintained. At this time, the valve body is pressed and held by the push rod at the bottom dead center of the stopper, thereby closing the flow path, so that the position where the valve body contacts the valve seat member is constant, and as a result, the valve body and The durability of the valve seat member is improved.

In addition, even in this braking state, if the brake pedal is further depressed, the fluid pressure on the first port side increases, deforming or moving the valve seat member made of an elastic body, and the fluid on the first port side flows into the valve body. It passes through the flow path which is the abutting part of the valve seat member and reaches the second port,
Liquid will flow into the wheel cylinder from this second port. This allows the brake fluid pressure to be further increased.

(Example) Hereinafter, a description will be given based on the illustrated example of the present invention. FIG. 1 is a sectional view showing a brake fluid pressure holding device according to an embodiment of the present invention, and FIG. 2 is a sectional view showing the main part of FIG. 1.

The brake fluid pressure holding device 1 of the present invention shown in FIGS. 1 and 2 is designed to be incorporated into a hydraulic brake, as schematically shown in FIG. A master cylinder MC having a brake drum 4 and a wheel cylinder WC attached to a brake drum 4 are connected by a pipe. Therefore, brake pedal 2
When you depress the lever 7, the piston 5 in the wheel cylinder WC moves forward and
rotates and brakes the vehicle body.

As shown in FIG. 1, a brake fluid pressure holding device 1
The device main body 10 includes a valve portion 10a and a solenoid portion 1.
0b, and the valve portion 10a of the device body is formed with a first port 11 to which a pipe P1 on the master cylinder side is connected, and a second port 12 to which a pipe P2 on the wheel cylinder side is connected. There is. A thread is formed in each port 11, 12, and each pipe P1, P2 is threadedly connected to the device main body 10.

A retainer 15 having a bottomed hole 14 with an open tip is fitted into the accommodation hole 13 which is in communication with each of the ports 11 and 12. A sleeve 1 is attached to the outer periphery of the tip of this retainer 15.
6 is fitted into the sleeve 16, and a receiver 17 is fitted to this sleeve 16.
is installed. This receiver 17 has a valve body 2.
A hole for supporting the flow path 3 is formed, and a radial groove for forming a flow path 21 is further formed. Also,
A plug 18 that is screwed into a screw hole formed in the rear end of the housing hole 13 is pressed against the rear end surface of the retainer 15, and the retainer 15 is positioned at a predetermined position by this plug 18. In addition, code 19
is an O-ring for sealing between the listener 15 and the accommodation hole 13.

The retainer 15 has a bottomed hole 14 and a second port 1.
2 is formed, and the tip opening of the bottomed hole 14 can communicate with the first port 11 via a groove formed in the receiver 17, The bottomed hole 14 and the opening 20 form a flow path 21 that allows the first port 11 and the second port 12 to communicate with each other.

A valve seat member 22 is attached to the stepped portion formed by the tip of the retainer 15 and the inner peripheral surface of the sleeve 16, and a valve body (ball) that contacts the tapered receiving surface formed on the valve seat member 22 is attached. )23 is
It is located on the first port 11 side with respect to the valve seat member 22.

"24" shown in FIG. 1 is a rod-shaped stopper provided in the bottomed hole 14 of the retainer 15 and movable in the axial direction. While touching the bottom,
The tip of the stopper contacts the valve body 23, and in this state, the valve body 23 contacts the valve seat member 22 to close the flow path 21 and prevent the valve body 23 from moving in the direction of the valve seat member 22. It is regulated. A compression coil spring 26 is housed between the large diameter portion 25 formed in the stopper 24 and the bottom surface of the bottomed hole 14, and the spring 26 causes the valve body 23 to pass through the flow path. An elastic force is applied in the direction of opening 21. In addition, the large diameter portion 25 of the stopper 24
One or more grooves S for communicating liquid are formed in the groove.

Therefore, when the valve body 23 is separated from the valve seat member 22 and the flow path 21 is opened by the spring 26, when the brake pedal 2 shown in FIG. 4 is depressed, the oil in the master cylinder MC is released. flows into the wheel cylinder WC through the flow path 21, and the brake shoe 6 performs a braking operation.

The solenoid section 10b of the device main body 10 includes a bracket 31 fixed to the valve section 10a by a screw 30, and a housing 3 integrated therewith.
2, and a solenoid 33 is housed in the housing 32. A push rod 35 is attached to the iron core 34 operated by the solenoid 33, and the tip of the push rod 35 is adapted to come into contact with the valve body 23. The push rod 35 moves forward toward the valve body 23 by the operation of the solenoid 33, thereby bringing the valve body 23 into close contact with the valve seat member 22 against the elastic force of the spring 26. It operates to close the flow path 21. Therefore, when the solenoid 33 is activated, the oil in the wheel cylinder WC cannot return to the master cylinder MC.

In the brake fluid pressure retaining device having the structure shown in FIG. 1, the valve seat member 22 itself, including the portion that contacts the valve body 23, is entirely formed of an elastic member such as rubber. As shown in an enlarged view in FIG. 2, before the solenoid 33 is activated, the spring 26 moves the stopper 24 forward and the valve body 23 is moved against the valve seat, as shown by the imaginary line in FIG. Member 22
The flow path 21 is in an open state.
When the solenoid 33 is activated, the push rod 35 moves the valve body 23 toward the valve seat member 22 and presses it against it, as shown by the solid line in FIG.
In this state, since the valve seat member 22 is formed of an elastic member, it deforms and the valve member 22 comes into close contact with the valve body 23, as shown by the solid line in FIG. will be closed.

Furthermore, since the valve member 22 is made of an elastic material such as rubber, and the valve body 23 is located on the first port 11 side with respect to the valve member 22, as shown by the broken line in FIG. Even if the solenoid 33 is energized and activated, if the brake pedal 2 is further depressed under this condition, the first
Since the hydraulic pressure on the port 11 side is higher than the hydraulic pressure on the second port 12 side, the valve member 22 is deformed away from the valve body 23 by the hydraulic pressure, as shown by the broken line in FIG. The hydraulic pressure in the master cylinder MC will flow into the wheel cylinder WC.

To explain the operating state of the brake fluid pressure holding device of the present invention having the above configuration, when the solenoid 33 is not energized, the valve body 23 is separated from the valve seat member 23 and the flow path 21 is open. . In this state, when the brake pedal 2 shown in FIG.
It flows into the wheel cylinder WC through the brake shoe 6, and is braked by the brake shoe 6.

As a result of this braking operation, the solenoid 33 is energized in response to a predetermined electrical signal when the vehicle comes to a stop or almost a stop state. Then, the push rod 35 moves forward to bring the valve body 23 into close contact with the valve seat member 22. At this time, the forward position of the push rod 35 is such that the tip of the stopper 24 abuts the valve body 23 and the rear end abuts the bottom surface of the bottomed hole 14 when the spring 26 reaches the bottom dead center.
The stopper 24 is set by the stopper 24 retreating against the elastic force of the stopper 24.
This state is maintained while the solenoid 33 is energized, so even if the brake pedal 2 is released, the braking state continues to be maintained.

Even if the valve body 23 is once in close contact with the valve seat member 22 and the braking state is maintained, if the brake pedal 2 is further depressed, the hydraulic pressure applied from the master cylinder MC to the first port 11 Since the valve seat member 22 is made of rubber or the like, the valve seat member 22 deforms away from the valve body 23,
Hydraulic pressure will be supplied within the wheel cylinder WC. Thereby, it is possible to increase the brake holding pressure value while maintaining the braking state.

As described above, in the brake fluid pressure holding device of the present invention, the valve seat member 22 for opening and closing the flow path 21 in cooperation with the valve body 23 can be used as a check valve with the same simple structure. It also functions as a one-way flow valve.

FIGS. 3A and 3B are cross-sectional views showing brake fluid pressure holding devices according to other embodiments of the present invention, respectively;
The same reference numerals are given to the same members as those in the previous embodiment.

In the case shown in FIG. 3A, the valve seat member 22 is made of a rigid body such as metal, synthetic resin, or ceramics, and includes a first valve seat 22a with which the valve body 23 contacts, and a front surface of the first valve seat 22a and the retainer 15. and an elastic body 22b formed of an elastic material such as rubber. This elastic body 22b
is installed in a groove 40 formed on the rear surface of the first valve seat 22a, and is connected to the first valve seat 22a and the retainer 1.
It functions as a sealing material to ensure airtightness between the first valve seat 22a and the front surface of the retainer 15, and also functions as a cushioning material between the first valve seat 22a and the retainer 15.

That is, in the state shown in FIG. 3A, the push rod 35
is activated and presses the valve body 23 against the valve seat 22a until the rear end of the stopper 24 comes into contact with the bottom surface of the bottomed hole 14, thereby closing the flow path 21. At this time, the valve body 22a A slight gap S exists between the retainer 15 and the retainer 15, and this gap S is sealed by the elastic body 22b. When the hydraulic pressure on the first port 11 side rises from this state, this hydraulic pressure acts on the front surface of the valve body 22a, and as a result, the valve body 22a resists the elastic force of the elastic body 22b and the third
In Figure A, the robot tries to move to the left. At this time,
Since the valve body 23 is fixed by the push rod 35 and the stopper 24, the valve body 23 and the valve seat 22a are relatively separated and the liquid flows from the first port 11 side to the second port 12 side. It turns out. Therefore, when the brake pedal is further depressed from the braking state, the brake holding pressure can be increased while the braking state remains.

In this case, the receiver 1 is attached to the first valve seat 22a.
7 is attached, and this receiver 17 has a hole for accommodating the valve body 23 and a radial groove. Further, in the case shown in FIG. 3A, the large diameter portion 25 of the stopper 24 has a tapered shape, and even at its maximum diameter, the hole 14
The diameter is set smaller than the inner diameter of the
It is not necessary to form the groove S in the large diameter portion 25.

Furthermore, in the case shown in FIG. 3B, the elastic body 22b is formed of a compression coil spring instead of the rubber elastic body shown in FIG. 3A.

In this case, since it is necessary to use an O-ring 45 to ensure liquid tightness between the valve seat 22a and the retainer 15, the O-ring 45 is accommodated in a groove formed on the outer periphery of the valve seat 22a. This O-ring 45 is in contact with the inner peripheral surface of the sleeve 16 fixed to the tip of the retainer 15. In this case, a receiver 17 is fixed to the tip of the sleeve 16.

In the state shown in FIG. 3B, the push rod 35 operates to push the valve body 23 so that the rear end of the stopper 24 is in the bottomed hole 14.
The retainer 15 is pressed against the valve seat 22a until it comes into contact with the bottom surface of the retainer 15, thereby closing the flow path 21. At this time, there is a slight gap S between the valve seat 22a and the retainer 15. This gap S is sealed by an O-ring 45. When the hydraulic pressure on the first port 11 side rises from this state, this hydraulic pressure acts on the front surface of the valve body 22a, and as a result, the valve body 22a
tries to move to the left in FIG. 3B against the elastic force of the elastic body 22b. At this time, the valve body 23
is fixed by the push rod 35 and the stopper 24, so the valve body 23 and the valve seat 22
a is relatively spaced apart from the first port 11 side to the second port 11 side.
Liquid will flow to the port 12 side. Therefore, when the brake pedal is further depressed from the braking state, the brake holding pressure can be increased while the braking state remains.

In each of the embodiments described above, it is also possible to install the receiver 17 inside the valve portion 10a of the main body 10 of the device.

(Effects of the invention) As described above, according to the invention, the movable valve seat member for opening and closing the flow path in cooperation with the valve body is
It also functions as a one-way flow valve by itself, and even when the valve body is in contact with the valve seat member and the flow path is closed, the vehicle can be braked by pressing the brake pedal. The brake holding pressure can be further increased. and,
Since this device has a simple structure, it is possible to not only reduce manufacturing costs but also improve durability.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a brake fluid pressure holding device according to an embodiment of the present invention, FIG. 2 is an enlarged sectional view of the main part of FIG. 1, and FIGS. 3A and B are other embodiments of the present invention. FIG. 4 is a sectional view showing an example, and is a schematic diagram showing a state in which the brake fluid pressure holding device of the present invention is incorporated into a braking device of a vehicle. 11...First port, 12...Second port, 1
5... Retainer, 21... Channel, 22... Valve seat member, 22a... First valve seat member, 22b... Second valve seat member, 23... Valve body, 33... Solenoid, 3
5...Push rod, MC...Master cylinder, WC
...Wheel cylinder.

Claims (1)

[Claims for Utility Model Registration] (1) A first port 11 to which a pipe on the master cylinder MC side is connected and a second port 12 to which a pipe on the wheel cylinder (WC side) is connected are formed in the main body of the device; Each of the ports 1 in the device body
1 and 12 A valve body 2 that forms one flow path 21 that communicates with each other and opens and closes the flow path 21
3 is provided on the device main body, and a stopper 24 having a resilient force applied in a direction in which the valve body 23 contacts and opens the valve body 23 is provided on the device main body. A push rod 35 is provided in the device main body, and the push rod 35 is operated by a solenoid 33 in a direction to close the valve body 23 against the elastic force of the stopper 24. The pressure of the liquid reaching the inside of the flow path 21 from the first port 11 increases when the valve seat member 22 contacts the valve body 23 and closes the flow path 21. The brake fluid pressure holding device is configured to be movable so as to separate from the valve body 23 and open the flow path 21 when the valve body 23 is opened. (2) The brake fluid pressure holding device according to claim 1, wherein the valve seat member 22, including the portion that contacts the valve body 23, is entirely formed of a rubber material. (3) The valve seat member 22 includes a rigid valve seat 22a having a contact surface that comes into contact with the valve body 23, and an elastic body that is assembled to the valve seat 22a and is contractible in the opening/closing direction of the valve body 23. 22b. A brake fluid pressure holding device according to claim 1, which is formed by a brake fluid pressure holding device.