JPH0712145A - Vehicular braking device - Google Patents

Abstract

PURPOSE:To provide a vehicular braking device able to prevent the lowering of braking performance as well as to prevent the generation of knock back at the time of traveling on a bad road and during turning travel and moreover enabling the reduction of manufacturing cost. CONSTITUTION:A brake line 8 connecting a master cylinder 6 to a wheel disc brake 4 is provided with a solenoid valve 24. A hydraulic damper 26 is connected to the brake line 8 more on the disc brake 4 side than the solenoid valve 24. The solenoid valve 24 is closed by a timer switch 30 upon the lapse of the specified time after a brake pedal 20 is released and a release switch 28 is turned on.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle brake device that ensures a stable braking force.

2. Description of the Related Art In a vehicle equipped with a wheel disc brake, the disc rotor may tilt with respect to the caliper when the wheels receive a reaction force from the road surface during traveling on a rough road or during turning. When the disc rotor inclines with respect to the caliper in this way, the disc rotor comes into contact with the corners of the brake pad and pushes back the piston, and the stroke of the brake pedal fluctuates due to the increase in the gap between the disc rotor and the brake pad. The phenomenon occurs. When this phenomenon of knockback occurs, the stroke of the brake pedal is long, so when you press the brake pedal, the braking effectiveness will be delayed, or the braking effectiveness will deteriorate, resulting in poor braking performance. There was a problem such as doing. Further, since the phenomenon of knockback occurs due to the increase in the gap between the disc rotor and the brake pad, the occurrence can be suppressed by preventing the caliper piston from returning. Therefore, in order to solve this problem, a disc brake device disclosed in Japanese Utility Model Laid-Open No. 4-52631 is proposed. According to this disc brake device, the caliper is supported by the disc rotor by the follow-up mechanism, and the caliper follows the inclination of the disc rotor when traveling on a rough road or turning. . Therefore, the disc rotor is not inclined with respect to the caliper, and the caliper piston is not pushed back. That is, since the gap between the disc rotor and the brake pad does not increase, knockback is prevented.

However, since the above-mentioned disc brake device is provided with a mechanism for following the caliper to the disc rotor, not only the caliper and the support structure of the caliper are complicated, but also the cost is increased, which is not preferable. . The present invention has been made in consideration of the above circumstances, and an object thereof is to prevent the occurrence of knockback during traveling on a rough road or during turning, and
It is an object of the present invention to provide a vehicle brake device capable of preventing a decrease in braking ability and reducing the manufacturing cost.

In order to achieve the above-mentioned object, in a vehicle brake device of the present invention, a master cylinder that generates a brake pressure by operating a brake pedal and a brake pipe line to the master cylinder are provided. And a wheel disc brake connected to the brake disc, the opening and closing valve being provided in the brake pipe line, opened when the brake pedal is depressed, and released when the brake pedal is released. It is a thing. Further, it is preferable that the on-off valve is closed after a predetermined time has elapsed since the brake pedal was released. Further, a hydraulic damper may be provided in a brake pipe line connecting the wheel disc brake and the opening / closing valve.

According to the vehicle brake device of the invention, the on-off valve provided in the brake conduit is opened by depressing the brake pedal, and is closed by depressing the brake pedal. The on-off valve is closed after a predetermined time has elapsed since the brake pedal was released. Further, the hydraulic damper absorbs the pressure fluctuation in the brake pipe line on the wheel disc brake side when the opening / closing valve is closed.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described in detail below with reference to FIG. FIG. 1 shows a schematic configuration diagram of a vehicle brake device 2. The brake device 2 includes a wheel disc brake 4, a master cylinder 6 and a brake pipe line 8. The wheel disc brake 4 includes a disc rotor 12 and a caliper 16, and the disc rotor 12 is provided so as to rotate integrally with a wheel shaft 10 of a wheel. The caliper 16 includes a pair of brake pads 14 and a piston 18, and the piston 18 extends from the master cylinder 6 to the brake line 8.
It is actuated by the brake pressure supplied via. By the operation of the piston 18, the pair of brake pads 14 press the disc rotor 12 so as to sandwich the disc rotor 12 and generate a braking force on the wheels. A push rod 22 connected to the brake pedal 20 is connected to the master cylinder 6, and when the brake pedal 20 is depressed and the push rod 22 is pushed, the master cylinder 6 generates a brake pressure. An electromagnetic valve 24 is inserted in the middle of the brake pipe line 8 that connects the master cylinder 6 and the caliper 16. The electromagnetic valve 24 is an opening / closing valve with two ports and two positions. Solenoid 2 of this electromagnetic valve 24
A release switch 28 provided on the brake pedal 20 side is connected to 4a via a timer switch 30, and a current can be supplied from a power supply 32 of the vehicle. When the solenoid 24a is not energized, the electromagnetic valve 24 is opened by being urged by the spring 24b, so that the brake pressure can be supplied from the master cylinder 6 to the caliper 16 side. Further, the electromagnetic valve 24 is closed when its solenoid 24a is energized, and shuts off the supply of brake pressure from the master cylinder 6 to the caliper 16 side. The release switch 28 is interlocked with a brake lamp switch (not shown) of the brake pedal 20, and is turned off (OFF) when the brake pedal 20 is stepped on, and is turned on (ON) when the brake pedal 20 is released. ). The timer switch 30 is turned on after a predetermined time elapses after the brake pedal 20 is released and the release switch 28 is turned on. That is, the solenoid 24 a of the electromagnetic valve 24 is connected to the brake pedal 20.
Is released and the current is supplied from the power source 32 after the lapse of the predetermined time after the release switch 28 is turned on. Therefore, the electromagnetic valve 24 is not closed at the same time when the brake pedal 20 is released. Actuating the electromagnetic valve 24 in this manner is performed immediately after the brake pedal 20 is released.
There is a time lag until the brake oil is completely returned from the wheel disc 4 side to the master cylinder 6, and the electromagnetic valve 24 is not fully returned.
This is because the brake may not be completely released even if the brake pedal 20 is released when is closed. On the other hand, a hydraulic damper 26 is provided in the brake pipe 8 on the caliper 16 side of the electromagnetic valve 24. The hydraulic damper 26 is, for example, a shock absorber having a capacity of about 0.5 cc. The operation of the brake device will be described below. When the depression of the brake pedal 20 is released, the release switch 28 is on, and the solenoid valve 24 is closed by supplying current to its solenoid 24a. Since the electromagnetic valve 24 is closed,
The brake pipe 8 on the caliper 16 side of the electromagnetic valve 24 is a closed circuit, and the piston 18 in the caliper 16 is closed.
Is not going to move. Therefore, when the wheels of the vehicle receive a reaction force from the road surface during traveling on a rough road or during turning, the disc rotor 12 is driven by the caliper 16
The piston 18 does not tilt with respect to the brake pad 1
It is not pushed back to 4. Therefore, the occurrence of knockback can be prevented. Moreover, since the occurrence of knockback can be prevented, the braking performance does not deteriorate. Further, since the brake device 2 only has the electromagnetic valve 24 in the middle of the brake pipe line 8, the manufacturing cost can be reduced. When the electromagnetic valve 24 is closed, the drag of the brake pad 14 with respect to the disc rotor 12 causes a pressure change in the brake oil in the brake pipe line 8, which may cause a slight braking force. The pressure fluctuation of the brake oil is absorbed by the hydraulic damper 26. Therefore, when the electromagnetic valve 24 is closed, that is, when the brake is not activated,
Braking force does not occur. When the brake pedal 20 is stepped on, the release switch 28 is immediately turned off, the power supply to the electromagnetic valve 24 is released, and the electromagnetic valve 2 is released.
4 is opened. Then, the brake pressure is transmitted from the master cylinder 6 to the wheel disc brake 4 side via the brake pipe 8. The time from the depression of the brake pedal 20 to the opening of the electromagnetic valve 24 is extremely fast, and since the hydraulic damper 26 is set to have an extremely small capacity, the responsiveness of the brake is affected. Absent. When the brake pedal 20 is released again, the timer switch 30 acts so that the electromagnetic valve 24 is closed after a predetermined time has elapsed since the release switch 28 was turned off. Therefore, the electromagnetic valve 24 is closed after the return of the brake oil from the wheel disc brake 4 side to the master cylinder 6 is complete, and does not affect the normal brake release.

Since the vehicle brake device of the present invention is constructed as described above, it has the following effects. When the brake pedal is released, the brake line that connects the master cylinder to the wheel disc brake is closed by the on-off valve,
When the wheel receives a reaction force from the road surface during traveling on a rough road or turning, the disc rotor does not tilt with respect to the caliper, and the caliper piston is not pushed back to the brake pad. Therefore, the occurrence of knockback can be prevented. Also, because knockback can be prevented,
It is also possible to prevent deterioration of braking performance. Further, in this brake device, since the on-off valve is simply provided in the middle of the brake pipe, the manufacturing cost can be reduced. The hydraulic damper absorbs the pressure fluctuation of the brake oil in the brake pipe that occurs due to the drag of the brake pad with respect to the disc rotor when the on-off valve is closed, preventing the generation of braking force when the brake is not operating. To do. Further, the on-off valve is closed after a predetermined time has elapsed since the brake pedal was released, so that the brake oil is completely returned from the wheel disc brake to the master cylinder. Therefore, the closing of the open / close valve does not affect the release of the brake.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a disk break device.

[Explanation of symbols]

 2 Brake device 4 Wheel disc brake 6 Master cylinder 8 Brake pipeline 12 Disc rotor 14 Brake pad 16 Caliper 20 Brake pedal 24 Electromagnetic valve 26 Hydraulic damper 28 Release switch 30 Timer switch

Claims (3)

[Claims] 1. A brake device comprising: a master cylinder that generates a brake pressure by operating a brake pedal; and a wheel disc brake that is connected to the master cylinder via a brake pipe, wherein the brake device is provided in the brake pipe. A brake device for a vehicle, comprising: an opening / closing valve that is opened when a brake pedal is depressed and is closed when the brake pedal is released. 2. The brake device for a vehicle according to claim 1, wherein the on-off valve is closed after a predetermined time period has elapsed since the depression of the brake pedal was released. 3. The brake device for a vehicle according to claim 1, wherein a hydraulic damper is provided in a brake pipe line connecting the wheel disc brake and the opening / closing valve.