JPH1134835A - Brake pressure control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the air pressure from being accumulated in a back pressure chamber of a decay diaphragm and a hold diaphragm by providing a one-way valve to permit the air passage from an exhaust port side to an input port side in a flow passage to communicate the exhaust with the input port. SOLUTION: When a brake pedal is opened, the pressure on an input port 11 side becomes the atmospheric pressure, and the air pressure on an exhaust port 13 side is released into the atmosphere through a one-way valve 18. At the same time, the air pressure in a back pressure chamber 15a of a hold diaphragm 15 is released through a valve output port 14b of a hold valve 14 ...a valve exhaust port 14c ... the one-way valve 18. In addition, the air pressure on a back pressure chamber 17a side of a decay diaphragm 17 is released through a valve output port 16b of a decay valve 16 ... a valve input port 16a, and no air pressure is left in the back pressure chamber 15a of the hold diaphragm 15 and the back pressure chamber 17a of the decay diaphragm 17.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brake pressure control device capable of adjusting a brake pressure by an air control valve for antilock control.
In particular, when the anti-lock control is performed while the exhaust port in the control valve is blocked by snow, ice, mud, etc., and then when the brake pedal is released, the air on the diaphragm back pressure chamber side of the decay valve is released. The present invention relates to a brake pressure control device that can be reliably released to the atmosphere via a brake valve by returning the brake pressure to a brake valve side, thereby avoiding a brake dragging phenomenon.

[0002]

2. Description of the Related Art Conventionally, an air brake device which performs a brake operation by air pressure and has an air control valve for anti-lock control is well known. In such a brake device, an exhaust port in the valve has a snow port. In the state where the air on the exhaust port side is not released due to being blocked by ice, mud, etc., the anti-lock control is entered and the decompression valve side back pressure is not released during the decompression mode, so the brake pressure is maintained And the brakes are not released and the tires remain locked. Further, when the brake pedal is released in this state, the air pressure on the exhaust port side goes around the diaphragm back pressure chamber side of the decay valve, and acts on the plunger on the decay valve side, and the air pressure acting on the plunger returns. If the spring is stronger than the biasing force of the spring, the plunger will keep the flow path closed by air pressure, the air pressure in the hold valve and decay valve back pressure chamber will not be released, and residual pressure will be generated in the brake side, causing A drag phenomenon occurs.
Further, even if the brake pedal is depressed in a state in which the air pressure in the back pressure chamber on the hold valve side does not release, the hold valve may not open and the vehicle may enter a no-brake state.

As a brake device taking measures to prevent such a situation, for example, a brake device described in Japanese Patent Application Laid-Open No. 2-256555 is known. The brake pressure control device of the above publication discloses a brake valve between a brake valve and a brake device that converts a low pressure of compressed air pumped from the brake valve into a high oil pressure and brakes the wheels by the oil pressure. A modulator valve for selectively communicating the compressed air fed from the compressor to the brake device or reducing the pressure of the communicated compressed air, and selectively closing the modulator and closing the communication. Has a port provided between the brake valve and a line leading to the brake device, and a valve biased by a spring to the port side, and the valve selectively opens the port or closes the port. In the above configuration, the brake valve is provided in the modulator valve. An anti-lock brake device comprising: a check valve for preventing a flow from an upstream side to a downstream side in a pipe line before and after the valve between pipe lines leading to the brake device. Thus, it is possible to reduce or eliminate the brake drag after returning the brake pedal.

[0004]

However, in the brake device having the above-described structure, when the exhaust port is closed, the air on the brake device side is released via the aforementioned check valve when the brake pedal is opened. Although the brake drag phenomenon can be eliminated, the back pressure of the hold valve side and the decay valve side diaphragm is not released as usual, so there is a problem that the hold valve cannot be opened at the time of brake operation and the brake does not work. . In view of this, the present invention newly forms a flow path that connects the two paths between the exhaust port passage and the brake valve side passage in the air control valve, and forms a flow passage from the exhaust port side to the brake valve side in this flow path. Providing a one-way valve that allows flow prevents the residual pressure from being generated on the back pressure chamber side of the hold valve and decay valve when the brake pedal is released, causing a brake drag phenomenon or a state where the brake does not work. It is an object of the present invention to solve the above-mentioned problems by avoiding such problems.

[0005]

Means for Solving the Problems In order to solve the above problem, the present invention has been made to solve the above problem by providing a brake valve and a brake device for braking the wheels by the action of air pressure fed from the brake valve. An air control valve for selectively communicating the air pressure fed from the brake valve to the brake device or reducing the pressure of the communicated air pressure is opened, and In the brake pressure control device wherein the communication and the closing of the communication are performed by a diaphragm provided in a pipe leading from the brake valve to the brake device, an exhaust port side of the air control valve, a brake valve side passage, And a brake valve is formed in this flow path from the exhaust port side. Providing the one-way valve which permits flow to the side is a brake pressure control apparatus according to claim.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of a brake pressure control device according to the present embodiment, and FIG. 2 is a configuration diagram of a flow path of an air control valve. In FIG. 1, 1 is an air tank, 2 is a brake valve, 3 is a relay valve, 10 is an air control valve according to the present invention, 4 is an air master cylinder, 5 is a brake cylinder, and these constitute a brake pressure control device. I have.

In this brake pressure control device, when the brake pedal is depressed, the brake valve 2 opens, and the air corresponding to the depression force of the brake pedal is supplied from the air tank 1 to the air control valve 10 by the action of the relay valve 3. The output air from the control valve 10 acts on the air master cylinder 4, where the air pressure is converted to a hydraulic pressure, so that the brake cylinder 5 can be operated to operate the brake. The air master cylinder 4
May be omitted so that the air pressure can be directly supplied to the brake cylinder 5.

As shown in FIG. 2, the air control valve 10 has an input port 11 communicating with the brake valve 2,
It has a flow path provided with an output port 12 communicating with the air master cylinder 4 side and an exhaust port 13 for releasing air pressure to atmospheric pressure. In the flow path, a hold valve 14, a hold diaphragm 15, a decay A valve 16, a decay diaphragm 17, and a one-way valve 18, which is a feature of the present invention, are arranged as shown. In the drawing, a thick flow path is a main flow path during braking, and a thin flow path is a flow path on the back pressure side when each valve is controlled.

The input port 11 communicates with an output port 12 communicating with the air master cylinder 4 via a hold diaphragm 15 in the main flow path, and the output port 12 communicates with an exhaust port via a decay diaphragm 17 in the main flow path. 13. The hold diaphragm 15 has a function of interrupting communication between the input port 11 and the output port 12, and the decay diaphragm 17 has a function of interrupting communication between the output port 12 and the exhaust port 13.

The hold valve 14 has an enlarged configuration shown in FIG. 3. The hold valve 14 has a valve input port 14a, a valve output port 14b, and a valve exhaust port 14c. Is located within. Plunger 14
e is provided with flow passage blocking members 14f and 14g at both ends, and a spring 1 is provided between the flow passage blocking members 14f and 14g.
4h, and the urging force of the spring 14h causes the flow path blocking members 14f and 14g to elastically
a, 14c can be closed. The plunger 14e is normally urged leftward in the figure by the return spring 14k, and can be moved rightward from the state shown in the figure when the solenoid 14d is energized.

The valve input port 1 of the hold valve 14
4a communicates with the input port 11, the valve output port 14b communicates with the back pressure chamber 15a of the hold diaphragm 15, and the valve exhaust port 14c communicates with the exhaust port 13 on the main flow path. The output port 14b is shut off and the valve output port 14b
And the valve exhaust port 14c are in communication. When the solenoid 14d of the hold valve 14 is energized and the plunger 14e moves to the right in the drawing, the valve input port 14a and the valve output port 14b
And the valve output port 14b and the valve exhaust port 14c are shut off. The hold diaphragm 15 is formed of an elastic body, and is normally urged by a return spring 15b disposed on the back pressure chamber 15a side in a direction to close the communication between the input port 11 and the output port 12.

The decay valve 16 has the same configuration as the hold valve shown in an enlarged manner in FIG. 3, but as shown in FIG. 2, a port corresponding to the valve input port 14a of the hold valve 14 is connected to a valve discharge port 16c, and A port corresponding to the valve discharge port 14c is a valve input port 16a. The other configuration is the same as that of the hold valve 14.

The valve input port 1 of the decay valve 16
6a is on the input port 11 side communicating with the brake valve,
The valve output port 16b communicates with the back pressure chamber 17a of the decay diaphragm 17, the valve exhaust port 16c communicates with the exhaust port 13 on the main flow path side, and communicates with the valve input port 16a and the valve output port 16b when not in operation.
The valve output port 16b and the valve exhaust port 16c are shut off. When the solenoid 16d of the decay valve 16 is energized and the plunger 16e moves to the right in the drawing, the valve input port 16a and the valve output port 16b are shut off, and the valve output port 1
6b communicates with the valve exhaust port 16c.

The decay diaphragm 17 is made of an elastic material, and is always urged by a return spring 17b disposed on the side of the back pressure chamber 17a in a direction to close the communication between the output port 12 and the exhaust port 13. A bypass passage 19 is provided between the passage on the input port 11 side of the hold diaphragm 15 and the passage on the exhaust port 13 side of the decay diaphragm 17, and a passage on the exhaust port 13 side of the decay diaphragm 17 is provided in this passage. A one-way valve 18 is provided to allow the hold diaphragm 15 to pass through to the passage on the input port 11 side.

The operation of the brake pressure control device according to the above configuration will be described. When the brake pedal is depressed, the brake valve 2 opens, and the air corresponding to the depression force of the brake pedal is supplied from the air tank 1 to the air control valve 10 by the action of the relay valve 3. The air pressure flowing from the input port 11 of the air control valve 10 is applied to the hold diaphragm 15
To move the hold diaphragm 15 to the left in the drawing against the urging force of the return spring 15b to communicate the input port 11 and the output port 12. The air pressure flows to the brake device through the open flow path, and operates the brake cylinder 5 to operate the brake similarly to the conventional brake pressure control device.

At this time, the air pressure also acts on the decay diaphragm 17 from the output port 12 side, but is input to the back pressure chamber 17a of the decay diaphragm 17 via the valve input port 16a of the decay valve 16 → the valve output port 16b. Since the air pressure on the port 11 side acts, the decay diaphragm 17 does not open due to the air pressure on the brake device side. When the brake pedal is released, the pressure on the input port 11 side becomes the atmospheric pressure via the brake valve. At this time, the back pressure chamber 17a of the decay diaphragm 17 is input through the valve output port 16b of the decay valve 16 → the valve input port 16a. To communicate with port 11, hold diaphragm 15 or decay diaphragm 1
7 is opened by the air pressure on the brake device side, the air pressure on the brake device side is released to the atmosphere via the hold diaphragm 15 and the decay diaphragm 17, and the brake is released.

When the brake is activated, the anti-lock control is started, and when a command to hold the brake pressure is issued, the solenoid 14d of the hold valve 14 is energized and the plunger 14e
Operates, and the valve input port 14 of the hold valve 14
a and the valve output port 14b are communicated with each other, and the air pressure from the air tank is applied to the back pressure chamber 15a of the hold diaphragm 15.
, The communication between the input port 11 and the output port 12 is cut off, and the air pressure on the brake device side is maintained at the air pressure at that time. When the brake pressure reducing command is issued, the solenoid 16d of the decay valve 16 is energized to operate the plunger 16e, and the decay valve 16 is connected to the valve output port 16b.
And the valve exhaust port 16c are communicated with each other, and the air pressure on the back pressure chamber 17a of the decay diaphragm 17 is released while the air pressure is applied to the back pressure chamber 15a of the hold diaphragm 15, so that the air on the brake device side is released. The pressure is exhausted from the exhaust port 13 via the decay diaphragm 17, and the brake pressure is reduced.

When the exhaust port of the air control valve is closed by snow, ice, mud, etc. and the air on the exhaust port side is not released, the air pressure in the back pressure chamber of the decay diaphragm and the hold diaphragm is as follows. Open. When the anti-lock control is started and a command to hold the brake pressure is issued, the hold valve 14 is operated, the valve input port 14a and the valve output port 14b of the hold valve 14 are communicated, and the air pressure from the air tank 1 is applied to the hold diaphragm 15 The hold diaphragm 15 cuts off the communication between the input port 11 side and the output port 12 side, and the air pressure on the brake device side is held at the air pressure at that time.

When the brake pressure reducing command is issued, the decay valve 16 is operated, and the valve output port 16b and the valve exhaust port 16c are connected on the decay valve 16 side.
The air pressure in the back pressure chamber 17a of the decay diaphragm 17 is exhausted, and the air pressure on the brake device side is exhausted through the decay diaphragm 17. However, at this time, if the exhaust port is closed by snow or the like, exhaust cannot be performed. Thereafter, when the brake pedal is released, the input port 11 side becomes atmospheric pressure, so that the air pressure on the exhaust port 13 side is released to the atmosphere via the one-way valve 18. At the same time, the hold diaphragm 15
The air pressure in the back pressure chamber 15a is also opened via the valve output port 14b of the hold valve 14, the valve exhaust port 14c, and the one-way valve 18, and the air pressure in the back pressure chamber 17a of the decay diaphragm 17 is Valve output port 16b → Valve input port 16
a, the back pressure chamber 15a of the hold diaphragm 15, the back pressure chamber 17a of the decay diaphragm 17
No air pressure remains. However, the back pressure chamber 17a of the decay diaphragm 17 and the valve output port 16
If the solenoid of the decay valve 16 is energized when the pressure b is high and the plunger 16e is operated, even if the energization of the solenoid of the decay valve 16 is terminated thereafter, the plunger 16e is kept at the pressure contained in the valve output port 16b and the valve exhaust port 16c. When the return spring is defeated, the plunger 16e cannot return and the pressure in the back pressure chamber 17a of the decay diaphragm 17 does not release, and after that, the energization of the solenoid of the hold valve 14 ends and the plunger 14e returns. A mode in which high pressure is confined in the hold-side diaphragm back pressure chamber 15a and the hold valve does not open and the pressurization failure occurs is achieved by returning the confined pressure to the brake valve side after releasing the brake valve by the one-way valve 18. To resolve.

As described above, when the brake pedal is released in the anti-lock control and the pressure reduction mode is set, the air pressure which always flows to the hold diaphragm back pressure chamber side is supplied via the one-way valve 18 and the decay diaphragm. The air pressure sneaking into the back pressure chamber side is input port 1 when the pressure is low.
1 to the atmosphere, and when the pressure is high, the containment pressure is eliminated by the above-described movement, so that the brake dragging phenomenon can be eliminated. Further, once the brake pedal is released, the normal brake is applied again. Even when the brake pedal is depressed, it is possible to avoid a situation in which the vehicle enters the no-brake state. As described above, the present invention newly forms a flow path that connects the exhaust port passage and the brake valve side passage, and provides a one-way valve that allows a flow from the exhaust port side to the brake valve side in this flow path. Therefore, generation of residual pressure of the hold valve and the decay valve can be prevented.

[0021]

As described in detail above, the present invention provides an exhaust port side in a flow path connecting an exhaust port and an input port even when the exhaust port is closed by snow, ice, mud, or the like. A one-way valve is provided to allow air to pass through to the input port side, so that when the brake pedal is released and the input port side is at atmospheric pressure, the air pressure at the exhaust port side always passes through the one-way valve through the input port side. Because it is opened to the atmosphere, the air pressure does not accumulate in the back pressure chamber of the decay diaphragm and hold diaphragm, and it is possible to achieve an excellent effect that it is possible to avoid a situation in which the brake is dragged or the brake does not work. .

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of the present brake pressure control device.

FIG. 2 is a configuration diagram of an air control valve used in the brake pressure control device.

FIG. 3 is an enlarged sectional view of a hold valve arranged in the air control valve.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Air tank 2 Brake valve 3 Relay valve 4 Air master cylinder 5 Brake cylinder 10 Air control valve 11 Input port 12 Output port 13 Exhaust port 14 Hold valve 15 Hold diaphragm 16 Decay valve 17 Decay diaphragm 18 One way valve 19 Bypass flow path

Claims (1)

[Claims] An air pressure pumped from a brake valve is selectively supplied to a brake device between a brake valve and a brake device that brakes a wheel by the action of air pressure fed from the brake valve. An air control valve is opened to communicate with or to reduce the pressure of the communicated air pressure. The selective communication at the air control valve and the closing of the communication are performed from the brake valve to the brake device. In a brake pressure control device configured to be performed by a diaphragm provided in a communicating pipe, a flow path communicating between an exhaust port side of the air control valve and a brake valve side passage is formed, and an exhaust port is formed in the flow path. Features a one-way valve that allows flow from the side to the brake valve side And brake pressure control device.