JPH02220B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an anti-skid brake device used in a brake device for a vehicle or the like.

Conventionally, as this type of device, for example,
As shown in Japanese Patent No. 76774, the first one prevents liquid movement from the master cylinder to the wheel cylinder.
a shutoff valve; a second shutoff valve provided between the first shutoff valve and the wheel cylinder to prevent liquid movement toward the first shutoff valve; The hydraulic pressure of the cylinder is received at the other end by hydraulic pressure from a hydraulic pump and is moved according to the hydraulic pressure difference acting on both ends, thereby opening and closing the first shutoff valve and increasing/decreasing the volume on the wheel cylinder side. a bypass passage that directly communicates the master cylinder and the wheel cylinder; a third shutoff valve that shuts off the bypass passage; and a plunger provided for opening and closing the second shutoff valve and the third shutoff valve, and When the pressure pump is normal, the second
A piston is known that has a piston that is in a position that opens a shutoff valve and closes the third shutoff valve, and is displaced to a position that closes the second shutoff valve and opens the third shutoff valve when the hydraulic pump fails. ing.

However, in the conventional system, the pressure from the master cylinder and the pressure from the hydraulic pump act oppositely on the piston, and when the hydraulic pump fails, the pressure in the master cylinder rises to a higher level than the pressure of the hydraulic pump. This moves the piston to a position where the second shutoff valve is closed and the third shutoff valve is opened. Therefore, when the brakes are applied, a portion of the discharge fluid supplied from the master cylinder to the wheel cylinder via the bypass passage is consumed to displace the piston to the above position.
There is a problem in that the pressure in the master cylinder is not quickly transmitted to the wheel cylinders, resulting in a delay in the start-up of brake operation.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide an anti-skid brake device that can quickly supply the output of a master cylinder to a wheel cylinder in the event of a pump failure. In order to achieve this, the piston has one pressure receiving part that always receives atmospheric pressure, and one that receives negative pressure when the hydraulic pump is normal,
The other pressure receiving part receives atmospheric pressure when the hydraulic pump fails.

By doing this, the piston is displaced not by the master cylinder pressure but by the pressure difference, so if the hydraulic pump fails, the fluid discharged from the master cylinder will be consumed to displace the piston. pressure is quickly transmitted to the wheel cylinder.

Hereinafter, the anti-skid brake device of the present invention will be explained in detail based on the illustrated embodiment.

FIG. 1 is a diagram showing an embodiment of the present invention.

In the figure, the anti-skid brake device is
The device 1, designated as a whole by 1, has a tandem master cylinder 3 actuated by the driver of a vehicle or the like via a brake pedal 2, one pressure chamber of the master cylinder 3 is connected to a pipe 4. The other pressure chamber is connected to the front wheel brake devices 9, 11 through a pipe 8. A brake switch 11 is closed when the driver depresses the brake pedal 2 to turn on a brake lamp (not shown), and is connected to a control circuit (not shown) for anti-skid control.

The regulator 5 includes a pressure regulator 12 that regulates the output of the master cylinder 3, that is, brake pressure, which is supplied to the rear wheel brake devices 6 and 7, and a generator that generates high pressure to operate the pressure regulator 12. 13.

The inlet port 14 of the pressure regulating section 12 and the inlet port 15 of the generating section 13 are connected to the discharge side of a hydraulic pump 16 driven by an engine of a vehicle, etc. Drain port 17 and
A drain port 18 of the generating section 13 is connected to a liquid storage tank 20 via a piping 19 indicated by a broken line. Further, the outlet port 21 of the generator 13 is connected to the liquid storage tank 20 via a pipe 22 and a power steering device 23.

A pressure switch 25 connected to the anti-skid control circuit described above is connected to the piping 24 connected to the discharge side of the liquid pump 16.
The pressure switch 25 is configured to close when the hydraulic pump 16 is driven and relatively low pressure is generated in the pipe 24 due to pipe resistance or the like.

The pressure regulating section 12 of the regulator 5 includes a master cylinder 3.
An inlet chamber 26 that communicates with the side and an outlet chamber 27 that communicates with the rear wheel brake devices 6 and 7 are provided, and both chambers 26 and 27 have an approximately U-shaped main passage 28 and an approximately L-shaped bypass passage. 29, they can communicate with each other. In the main passage 28, a check valve 32 as a first cutoff valve that prevents liquid movement from the inlet chamber 26 toward the outlet chamber 27 is provided on a stepped piston 30 as a plunger and receives pressure on the outlet chamber 27 side. The check valve 32 is arranged to be opened and closed by the small diameter portion 31, and a pressure regulating chamber 33 whose volume is increased or decreased according to the movement of the stepped piston is provided on the outlet chamber 27 side of the check valve 32. be.

Further, the right end side of the large diameter portion 34 of the stepped piston 30 is configured to receive atmospheric pressure, and the left end side is configured to receive the solenoid valve 3.
The stepped piston 30 is configured to receive pressure from the hydraulic pump 16 introduced through the stepped piston 5, and the stepped piston 30 is moved in accordance with the hydraulic pressure difference acting between the left end side of the large diameter portion 34 and the small diameter portion 31. It's summery. Solenoid valve 35
is a pressure chamber 36 formed on the left end side of the large diameter portion 34
is operated in response to a command from a control circuit for anti-skid control so as to selectively communicate with piping 24 and piping 19.

A main passage 2 is provided from the outlet chamber 27 to the outlet chamber 27.
A tilted check valve 37 serving as a second shutoff valve that prevents liquid movement toward the outlet chamber 27 is disposed so as to open by engaging with a branch 38 extending from the bypass passage 29 toward the outlet chamber 27. The branch portion 38 is provided on the side of the small diameter protrusion 41 of the piston 40.

The piston 40 has a pressure receiving part that constantly receives atmospheric pressure at one end on the small diameter protrusion 41 side, and a pressure receiving part that receives negative pressure or atmospheric pressure introduced into the negative pressure chamber 39 in response to switching of a solenoid valve 58, which will be described later, at the other end. A pressure receiving part is provided respectively, and a seat part 4 is provided at the left end of the small diameter protrusion 41 and near the left end.
2 and 43 respectively, and relatively light springs 4
4, the entire body is urged to move to the left. One seat 42 has an opening 4 in the main passage 28.
5 to block communication between the inlet chamber 26 and the main passage 28 , and the other seat 43 is configured to block communication between the bypass passage 29 and the inlet chamber 26 together with the opening 46 of the bypass passage 29 . and seat part 43
and the opening 46 function as a third shutoff valve. When atmospheric pressure is introduced into the negative pressure chamber 39, the piston 40 closes the check valve 37 and closes the seat portion 4.
3 to the bypass position where it is separated from the aperture 46,
When negative pressure is introduced into the negative pressure chamber 39, the check valve 37 is opened and the seat 43 is moved to the non-bypass position where it is seated in the opening 46. In the bypass position, The inlet chamber 26 and the outlet chamber 27 communicate with each other via the bypass passage 29, and in the non-bypass position, the inlet chamber 26 and the bypass passage 2
The direct communication with the inlet chamber 26 and the outlet chamber 27 is cut off.
and communicate with each other through the main passage.

The generator 13 is a spool 47 that can be moved left and right.
At the end of the small diameter portion 48 provided at the left end of the spool 47, there is a diaphragm 50 that can receive atmospheric pressure on the right side and negative pressure in the negative pressure chamber 49 on the left side.
is installed, and this diaphragm 50 is
Due to the pressure difference acting on both sides, the spool 47
can be moved to the left against the tension of the return spring 51 that urges it to the right. 52 is a spring receiver.

The spool 47 itself faces the chamber leading to the drain port 18 on its left and right sides, and is provided with a groove 53 in the center that constantly communicates with the outlet port 21. Depending on the position of the spool 47, the groove 53 and By changing the communication area with the groove 54 communicating with the inlet port 15, in other words, by changing the effective passage area, high pressure is generated within the pipe 24. That is, when the spool 47 is moving to the right due to the tension of the return spring 51, a relatively low pressure is generated in the pipe 24 due to pipe resistance, and conversely, the spool 47 is moved to the right by the small diameter portion 48 of the pipe 24. When the left end is in the position where it abuts the protrusion 55, a relatively high pressure sufficient to perform pressure regulation control in the pressure regulating section 12 is generated in the pipe 24.

A passage 56 whose one end communicates with the atmosphere is provided between the pressure regulating part 12 and the generation part 13.
The other end side of 6 communicates with both negative pressure chambers 39, 49, and cuts off the communication between this passage 56 and both negative pressure chambers 39, 49, and connects to negative pressure chambers (not shown) through an internal passage 57. A solenoid valve 58 capable of communicating both negative pressure chambers 39, 49 is provided with a pressure source. This solenoid valve 58 is connected to the control circuit for anti-skid control described above, and is connected to the pressure switch 25 and the brake switch 11.
When both of the negative pressure chambers 39 and 49 are closed, the negative pressure chambers 39 and 49 are connected to a negative pressure source, and during demagnetization, both negative pressure chambers 39 and 49
be positioned so that it communicates with the atmosphere.

The negative pressure source stores the negative pressure generated by the suction force of the intake manifold of the gasoline engine or the negative pressure generated by driving the vacuum pump.

The operation of the above-mentioned embodiment will be described below.

If the engine of the vehicle is currently being driven and the vehicle is running, negative pressure is stored in the negative pressure source and the pump 16 is continuously discharging liquid. At this time, since the brake is not applied, the brake switch 11 is open, so the solenoid valve 58 is demagnetized and each negative pressure chamber 39, 49 is open.
, the spool 47 is moved to the right by the biasing force of the return spring 51, and the fluid discharged from the pump 16 is sent to the power steering device 23 without restriction, and the piston 40 is moved to the right by the biasing force of the return spring 51. It is moved to the bypass position with a biasing force of 44. Note that the pressure switch 25 is closed because the pump 16 is operating normally.

When the driver of the vehicle or the like depresses the brake pedal 2 to apply the brakes in this state, the brake switch 11 closes almost simultaneously with the start of depressing, and the solenoid valve 58 is energized.

Then, by introducing negative pressure into each of the negative pressure chambers 39 and 49, the piston 40 moves to the non-bypass position and moves to a position where the small diameter portion 48 of the spool 47 abuts the protrusion 55. This generates high pressure within the pipe 24, which is introduced into the pressure chamber 36, moves the stepped piston 30 to the right, opens the check valve 32, and causes the pressure regulating chamber to open. 33 at a position that minimizes its volume.

Then, when you press brake pedal 2 further,
Pressure fluid discharged from the master cylinder 3 flows through the main passage 2
8 to the rear wheel brake devices 6 and 7,
Together with the front wheel brake devices 9 and 10 to which pressurized fluid is sent out without restriction from the master cylinder 3, the vehicle etc. are decelerated.

During such brake operations, if the brake pressure supplied to the rear wheel brake devices 6 and 7 is excessive,
The rear wheels become skidded and anti-skid control is started. Then, the electromagnetic valve 35 is energized to cut off the communication between the pressure chamber 36 and the pipe 24, connect the pressure chamber 36 and the pipe 19, and cause the pressure liquid in the pressure chamber 36 to flow out to the tank 20. Therefore, the stepped piston 30 moves to the left due to the pressure in the pressure regulating chamber 33, closes the check valve 32, and closes the rear wheel brake device 6,
7, and after the check valve 32 closes, the stepped piston 30 is further moved to the left to increase the volume of the pressure regulating chamber 33. Wheel brake device 6,
Reduce the pressure supplied to 7. This pressure drop brings the wheels out of the skid condition.

After that, when the wheel rotation recovers too much, the solenoid valve 35 is demagnetized, the pressure chamber 36 is connected to the piping 24, pressure fluid is supplied to the pressure chamber 36, and the stepped piston 3
0 to the right to reduce the volume of the pressure regulating chamber 33. As a result, the pressure being supplied to the rear wheel brake devices 6, 7 increases, and the brakes are strongly applied.

In this way, by repeatedly increasing and decreasing the pressure, the pressure is controlled to prevent skidding of the rear wheels.

The above explanation is for when each part is normal, but the case when the pump 16 breaks down will be described below.

Assume that a vehicle or the like is currently running and no liquid is being discharged into the pipe 24 even though the pump 16 is being driven.

Then, since no pressure is generated in the pipe 24, the pressure switch 25 remains open, and the solenoid valve 58 is not energized even if the brake switch 11 is closed. Therefore, since negative pressure is not supplied to each negative pressure chamber 39, 49, the spool 47 is positioned on the right side by the return spring 51, and the piston 4
0 are each biased to the bypass position by a spring 44.

Therefore, the pressure fluid from the master cylinder 3 is supplied to the rear wheel brake devices 6, 7 without restriction through the bypass passage 29.

The above-described embodiments have the following effects.

That is, the bypass piston 40 does not receive negative pressure if the pressure switch 25, which closes at the low pressure generated when the pump 16 is operating normally, remains open. Since the piston 40 is previously biased to the bypass position by the biasing force of the spring 44, the piston 40 is located at the bypass position regardless of the brake fluid pressure, and therefore, there is no delay in the rise of the brake during braking.

Further, even when the pump 16 is normal, the piston 40 is moved to the non-bypass position almost simultaneously with the start of braking, and the spool 4 is moved to the non-bypass position.
When high pressure starts to be generated in the piping 24 due to the displacement of the stepped piston 30, the pressure regulating chamber 33
The volume of the piston 40 decreases to compensate for the increase in volume due to the displacement of the piston 40, so there is no delay in the start-up of the brake.

Note that in this embodiment, the seat portion 4 of the piston 40
Since the sealing area for the openings 45 and 46 of No. 2 and 43 is larger than the sealing area of the small diameter protrusion 41 for the bypass passage 29, in other words, the action of moving the piston 40 by the brake pressure Since the force is applied to the left side in the bypass position and to the right side in the non-bypass position, the brake is applied to hold the piston 40 at each position. Hydraulic pressure acts on it, and it has excellent reliability in achieving stable functions as a device.

As is clear from the above, according to the present invention, the pistons that open and close the second and third shutoff valves have one pressure receiving part that always receives atmospheric pressure, and one that receives negative pressure when the hydraulic pump is normal. However, when the hydraulic pump fails, the other pressure receiving part receives body pressure, and the piston is displaced by the pressure difference, so that part of the fluid discharged from the master cylinder is not consumed to displace the piston. As a result, there is no delay in the start-up of the brake, and the output of the master cylinder can be quickly supplied to the wheel cylinders.

It goes without saying that the present invention is not limited to the illustrated embodiment and can be implemented in various forms.

That is, for example, an example in which the solenoid valve 58 is energized and demagnetized only in response to the opening and closing of the pressure switch 25, and a closing signal of the brake switch 11 and the pressure switch 25
An example in which the solenoid valve 58 is excited by a combination of the closing signal of the pressure switch 25 and a signal indicating that the accelerator pedal has returned to the non-depressed position, instead of the combination with the closing signal of For example, it may be made proportional to the brake pressure.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1...Anti-skid brake device, 16...Hydraulic pressure pump, 39...Negative pressure chamber, 40...Piston.

Claims (1)

[Claims] 1. A first shutoff valve that prevents fluid movement from the master cylinder to the wheel cylinder; and a second shutoff valve that is provided between the first shutoff valve and the wheel cylinder and prevents fluid movement toward the first shutoff valve. The shutoff valve is disposed between the two shutoff valves, and receives the hydraulic pressure of the wheel cylinder at one end and the hydraulic pressure from the hydraulic pump at the other end, and is moved according to the hydraulic pressure difference acting on both ends. a plunger that opens and closes a first shutoff valve and increases or decreases the volume on the wheel cylinder side; a bypass passage that directly communicates the master cylinder and the wheel cylinder; a third shutoff valve that shuts off the bypass passage; A cutoff valve and a third cutoff valve are provided for opening and closing, and when the hydraulic pump is normal, the second cutoff valve is opened and the third cutoff valve is closed, and when the hydraulic pump is in a malfunction, the second cutoff valve is in a position. In the anti-skid brake device, the piston has one pressure receiving part that always receives atmospheric pressure, and a piston that is displaced to a position where the third shutoff valve is closed and the third shutoff valve is opened. An anti-skid brake device is provided with a pressure receiving part that receives negative pressure and another pressure receiving part that receives atmospheric pressure when the hydraulic pump fails.