JPH06312656A - Anti-skid brake device for vehicle - Google Patents

Abstract

PURPOSE:To ensure required braking force at the time of pump failure by setting the capacity of decompressive cylinder which relieves fluid pressure applied to the control mechanism of wheels smaller than working oil discharge capacity by the full stroke of a master cylinder which operates the control mechanism. CONSTITUTION:A master cylinder 22 receives brake operation force to operate a control mechanism 2 and brake rotating wheels. The control means 6 judges if wheel locking is proper based on the input from a wheel speed sensor 7 which detects the rotational speed of the wheels to operate a directional control valve 3, and relieves oil pressure applied to the control mechanism 2. The pump unit 5 returns working oil which is accumulated in the decompressive cylinder 23 to the master cylinder 22. With such a vehicle anti-skid brake device 21, the capacity of the decompressive cylinder 23 is set smaller than the discharge capacity of the working oil in the full stroke of the master cylinder 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antiskid brake device for a vehicle, which prevents the wheels from being locked during sudden braking.

[0002]

2. Description of the Related Art FIGS. 2 (A) and 2 (B) are configuration diagrams of a general anti-skid brake device used in vehicles such as automobiles and motorcycles. This anti-skid brake device 100 includes a master cylinder 1, a braking mechanism 2 that brakes the rotation of wheels, a directional control valve 3, and a pressure reducing cylinder 4.
, A pump unit 5, a control means 6, and a wheel speed sensor 7 for detecting the rotational speed of the wheels.

When the brake operating force from the brake pedal or the brake lever is applied to the master cylinder 1, the internal piston 1a is pushed in as shown in FIG. (Brake fluid) is discharged. On the other hand, the braking mechanism 2 is
It is composed of a disc rotor 2a that is provided integrally with the wheel so as to rotate, and a brake caliper 2b that sandwiches the disc rotor 2a.

The master cylinder 1 is connected to the directional control valve 3 by a flow path 8, and the directional control valve 3 is connected to the brake caliper 2b by a flow path 9. Further, the flow paths 8 and 9 are connected by a flow path 11, and the brake caliper 2 is provided in the middle of the flow path 11.
A check valve 12 that allows only the flow of hydraulic oil returning from b to the master cylinder 1 side is connected.

The depressurizing cylinder 4 is connected to the direction control valve 3 by a flow path 13, and the flow path 13 and the flow path 8 are connected by a flow path 14. The pump 5a of the pump unit 5 is connected to an intermediate portion of the flow path 14, and the check valve 1 that allows only the flow of hydraulic oil returning from the pressure reducing cylinder 4 to the master cylinder 1 side is provided before and after the pump 5a.
5, 16 are connected. The pump unit 5
Is equipped with a motor 5b for driving the pump 5a.

The control means 6 is connected to the solenoid 3a for operating the directional control valve 3, the motor 5b, and the wheel speed sensor 7.

In FIG. 2A, when the brake pedal or the brake lever is operated, the hydraulic oil in the master cylinder 1 is pressure-fed to the brake caliper 2b through the flow passages 8 and 9, and the hydraulic pressure causes the hydraulic oil to flow. The brake caliper 2b sandwiches the disc rotor 2a to brake the rotation of the wheels.

When the brake pedal or the brake lever is released, the working oil sent to the brake caliper 2b returns through the flow paths 9 and 8 and is refilled in the master cylinder 1, so that the hydraulic pressure is applied to the brake caliper 2b. It consists of hangings. Therefore, the braking of the wheels is released.

During sudden braking or braking on a slippery road surface, the possibility that the wheels will lock increases as the braking force increases. The control means 6 catches the sign that the wheel is locked by the input from the wheel speed sensor 7. At that time, the solenoid 3a is operated to move the directional control valve 3 from the state shown in FIG. ) To operate.

Then, the flow passage 8 is closed so that the hydraulic oil in the master cylinder 1 is not sent to the brake caliper 2b, and the hydraulic pressure applied to the brake caliper 2b due to the communication between the flow passage 9 and the flow passage 13 is reduced. 4 and the hydraulic oil is accumulated in the pressure reducing cylinder 4. For this reason,
The force with which the brake caliper 2b sandwiches the disc rotor 2a is relaxed, and the locking of the wheels is avoided. The hydraulic oil accumulated in the decompression cylinder 4 is returned to the master cylinder 1 by the operation of the pump unit 5, and the piston 1a of the master cylinder 1 is pushed back.

As soon as there is no sign that the wheels will be locked, the control means 6 causes the directional control valve 3 to move from the state shown in FIG.
In order to return to the state of (A), the hydraulic oil discharged from the master cylinder 1 is sent to the brake caliper 2b again, and the brake caliper 2b brakes the rotation of the wheels.

By rapidly repeating these operations (anti-skid action), a strong braking force can be obtained without locking the wheels, and the vehicle can be stopped safely at the shortest distance.

[0013]

By the way, in the anti-skid brake device 100 constructed as described above, the pump unit 5 should fail and the hydraulic oil accumulated in the pressure reducing cylinder 4 may be returned to the master cylinder 1. When it becomes impossible, the control means 6 senses the failure and continues to increase or decrease the hydraulic pressure applied to the brake caliper 2b until all the hydraulic oil in the master cylinder 1 is sent to the pressure reducing cylinder 4. It is conceivable to immediately stop the operation and operate it in the same manner as a general braking device.

As described above, when the pressure increase / decrease of the hydraulic pressure applied to the brake caliper 2b is continued until all the hydraulic oil in the master cylinder 1 is sent to the pressure reducing cylinder 4, even if the pump unit 5 fails, it will take a while. Since the anti-skid action is obtained and the operation stroke of the brake pedal or the brake lever is suddenly deepened, there is an advantage that the driver can immediately recognize the failure.

However, as shown in FIGS. 2 (A) and 2 (B), since the capacity of the decompression cylinder 4 has been made larger than the working oil discharge capacity of the full stroke of the master cylinder 1 in the prior art, the inside of the master cylinder 1 If the pressure increase / decrease of the hydraulic pressure applied to the brake caliper 2b is continued until all the hydraulic oil of (1) is sent to the pressure reducing cylinder 4, the piston 1a of the master cylinder 1 bottoms out, and thereafter the braking force is not exerted. In this case, in order to obtain the braking force again, it is necessary to depress the brake pedal or re-grip the brake lever, which may increase the braking distance.

On the other hand, as described above, when the pump unit 5 fails and the anti-skid action is immediately stopped and the brake device is operated in the same manner as a general brake device, the anti-skid action is suddenly performed during braking accompanied by the anti-skid action. The operation was interrupted, and the wheels could be locked without the passengers of the vehicle having to deal with it.

The present invention has been made in order to solve the above problems. Even if the pump unit should fail, an antiskid action can be obtained for a while, and the brake pedal or the brake lever can be re-operated thereafter. It is an object of the present invention to provide an anti-skid brake device for a vehicle that can exhibit a braking force similar to that of a general brake device without using the vehicle.

[0018]

In order to achieve the above object, a vehicle anti-skid brake device according to the present invention includes a master cylinder for actuating a braking mechanism by receiving a brake operating force to brake the rotation of wheels. A wheel speed sensor that detects the rotation speed of the wheel and a sign that the wheel is locked by the input from this wheel speed sensor, and at that time, operate a directional control valve to release the hydraulic pressure applied to the braking mechanism to the decompression cylinder. And a pump unit that is also controlled by the control means and returns the hydraulic oil accumulated in the depressurizing cylinder to the master cylinder, the capacity of the depressurizing cylinder is set to the full capacity of the master cylinder. It is characterized in that it is smaller than the hydraulic oil discharge capacity for the stroke.

[0019]

According to the anti-skid brake device for a vehicle having the above-mentioned structure, the control means is normally operated when a sign that the wheels are locked is generated when the anti-skid action is applied when the pump unit fails. As described above, the hydraulic pressure applied to the brake caliper is released to the decompression cylinder in order to loosen the braking force, and hydraulic oil is accumulated in the decompression cylinder.

The hydraulic oil accumulated in the depressurizing cylinder is not returned to the master cylinder because the pump unit has failed. Therefore, as the pressure applied to the brake caliper is repeatedly increased and decreased, the pressure reducing cylinder is filled with the hydraulic oil.

Since the capacity of the depressurizing cylinder is smaller than the capacity of the master cylinder for discharging the full stroke of hydraulic oil, even if the depressurizing cylinder is filled with the hydraulic oil, the piston of the master cylinder does not bottom out. Therefore, after the pressure reducing cylinder is filled with hydraulic oil,
Even if the brake pedal or the brake lever is not operated again, a braking force similar to that of a general brake device is exerted.

[0022]

EXAMPLE An example of the present invention will be described below with reference to FIG.
Explanation will be given with reference to (B).

The components other than the master cylinder 22 and the pressure reducing cylinder 23 of the antiskid brake device 21 according to the present invention are the same as those of the conventional antiskid brake device 100 shown in FIGS. 2 (A) and 2 (B). Therefore, the same reference numerals are given and the description thereof is omitted.

The capacity of the decompression cylinder 23 is smaller than the working oil discharge capacity for the full stroke of the master cylinder 22. For example, master cylinder 2
When the hydraulic oil discharge capacity of No. 2 is 1.5 cc, the capacity of the pressure reducing cylinder 23 is set to 0.6 cc to 1.3 cc.

In this anti-skid braking device 21, if the pump unit 5 should fail and the braking that requires the anti-skid action is performed at that time, the anti-skid braking device 21 operates as follows.

First, when there is no sign that the wheels are locked, the hydraulic oil in the master cylinder 22 is pressure-fed to the brake caliper 2b through the flow paths 8 and 9, and the hydraulic pressure causes the brake caliper 2b to move the disk rotor 2a. It is pinched and brakes the rotation of the wheels.

When the control means 6 captures a sign that the wheels are locked by the input from the wheel speed sensor 7, the control means 6 is controlled.
Operates the solenoid 3a as usual to change the directional control valve 3 from the state of FIG. 1 (A) to the state of FIG. 1 (B). Then, the flow passage 8 is closed and the hydraulic oil in the master cylinder 22 is no longer sent to the brake caliper 2b, and the hydraulic pressure applied to the brake caliper 2b is released to the decompression cylinder 23 due to the communication between the flow passage 9 and the flow passage 13. The working oil is removed and accumulated in the depressurizing cylinder 23. Therefore, the force with which the brake caliper 2b sandwiches the disc rotor 2a is relaxed, and the locking of the wheels is avoided.

The hydraulic oil accumulated in the pressure reducing cylinder 23 is
Since the pump unit 5 is out of order, it cannot be returned to the master cylinder 22. Therefore, the brake caliper 2b
As the pressurization and depressurization of the hydraulic pressure applied to the pressure reducing cylinder 23 is repeated, the hydraulic oil is filled to the full capacity of the pressure reducing cylinder 23.

As described above, since the capacity of the decompression cylinder 23 is smaller than the working oil discharge capacity of the master cylinder 22 for the full stroke, the decompression cylinder 2
3 is filled with hydraulic oil, the master cylinder 22
The piston 22a has no bottom.

The control means 6 holds the directional control valve 3 in the state shown in FIG. 1 (A) at the time when the pressure reducing cylinder 23 is filled with hydraulic oil, and applies the hydraulic pressure of the master cylinder 22 to the brake caliper 2b. Therefore, after that, it is possible to obtain the same braking force as a general brake device without re-operating the brake pedal or the brake lever.
There is no fear of increasing the braking distance.

In this way, even if the pump unit 5 should fail, the antiskid action will be obtained for a while, and the braking force similar to that of a general brake device will be exerted thereafter, so that the pump unit 5 will fail. At the same time, the antiskid action is not interrupted and time is provided for the vehicle occupant to recognize and address the failure.

[0032]

As described above, the vehicle anti-skid brake device according to the present invention receives the brake operating force to operate the braking mechanism to brake the rotation of the wheels, and the rotation speed of the wheels. And a control means for detecting the sign that the wheel is locked by the input from this wheel speed sensor and operating the directional control valve to release the hydraulic pressure applied to the braking mechanism to the pressure reducing cylinder at the same time. In a vehicle anti-skid brake device equipped with a pump unit which is controlled by a control means and returns the hydraulic oil accumulated in the depressurizing cylinder to a master cylinder, the capacity of the depressurizing cylinder is set to the hydraulic oil for the full stroke of the master cylinder. It is characterized in that it is smaller than the discharge capacity.

In the vehicle anti-skid brake device thus constructed, the control means is usually provided to prevent the wheels from being locked if the anti-skid action is applied in the event of a failure of the pump unit. As described above, the pressurization and depressurization of the hydraulic pressure applied to the brake caliper is repeated, and the hydraulic oil is accumulated in the depressurization cylinder.

The hydraulic oil accumulated in the depressurizing cylinder is not returned to the master cylinder because the pump unit is out of order, and therefore the depressurizing cylinder is filled with the hydraulic oil. Is smaller than the hydraulic oil discharge capacity for the full stroke of the master cylinder, the piston of the master cylinder will not bottom up even if the pressure reducing cylinder is filled with hydraulic oil.

Therefore, after the pressure reducing cylinder is filled with the hydraulic oil, it is possible to obtain the same braking force as that of a general brake device without re-operating the brake pedal or the brake lever, and the braking distance is extended. There is no fear.

In this way, even if the pump unit should fail, the antiskid action will be obtained for a while, and after that, the braking force similar to that of a general brake device will be exerted.
The antiskid action is not interrupted at the same time as the pump unit fails, providing time for the vehicle occupant to recognize and address the failure.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an anti-skid brake device showing an embodiment of the present invention, (A) is a diagram showing a state in which there is no sign that the wheel is locked, and (B) is a sign that the wheel is locked. The figure which shows the state in the case of occurrence.

FIG. 2 is a configuration diagram of an anti-skid brake device showing a conventional technique, (A) is a diagram showing a state in which there is no sign that the wheel is locked, and (B) is a sign that the wheel is locked. The figure which shows the state when there is.

[Explanation of symbols]

 2 Braking mechanism 3 Directional control valve 5 Pump unit 5a Pump 5b Motor 6 Control means 7 Wheel speed sensor 21 Anti-skid brake device 22 Master cylinder 23 Pressure reducing cylinder

Claims (1)

[Claims] 1. A master cylinder that receives a brake operating force to actuate a braking mechanism to brake the rotation of a wheel, a wheel speed sensor that detects the rotational speed of the wheel, and a wheel that receives an input from the wheel speed sensor. A control means for catching the sign of locking and operating the directional control valve to release the hydraulic pressure applied to the braking mechanism to the decompression cylinder at that time, and the hydraulic oil accumulated in the decompression cylinder controlled by the control means as well as the master cylinder. An anti-skid brake device for a vehicle, comprising: a pump unit for returning to the vehicle, wherein the capacity of the decompression cylinder is smaller than the hydraulic oil discharge capacity of a full stroke of the master cylinder.