JPS5823736Y2 - Pressure control device for vehicle brake anti-skid - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a brake pressure control device for anti-skid control of a vehicle equipped with an air brake device.

This type of brake pressure control device for anti-skid control consists of a solenoid valve device, and when a wheel skids or is about to skid, a control unit consisting of electronic components detects this and supplies the signal to the brake device for that wheel. The solenoid valve device exhausts the pressurized air to lower the brake pressure, and when the wheel recovers from the skid state, the solenoid valve device is demagnetized and pressurized air is supplied to the brake device again to reduce the brake pressure. Increase pressure -g
It's set.

In other words, a solenoid valve device is installed in the piping between the brake valve operated by the driver and the brake device, and when a brake release command is issued from the control unit, communication between the brake valve and the wheel brake device is cut off, and at the same time, the brake device is connected to the brake device. The supplied pressurized air is exhausted to lower the brake pressure, and the solenoid valve device is brought into communication by the brake command from the control unit, and the pressurized air from the brake valve is supplied to the wheel brake device to brake. Increase pressure to bribe.

Furthermore, if necessary, the solenoid valve device is shut off by a brake hold command from the control unit to keep the brake pressure supplied to the wheel brake device constant.

In this way, the brake pressure to the wheel brake equipment was controlled.

However, because the electromagnetic valve device is built into the piping between the brake valve and the wheel brake device, there is a delay in the start-up of the brake, that is, the delay between when the driver operates the brake valve and when the wheel brake device applies the brake. It was necessary to make the passage area of the solenoid valve device sufficiently large so as not to increase the time delay.

Therefore, when a command to apply the brakes is given from the control unit during anti-skid control, pressurized air from the brake valve is supplied to the wheel brake device through the large passage area of the solenoid valve device, and the brake pressure of the wheel brake device is The result was a rapid increase.

This sudden increase in brake pressure not only causes abnormal shock vibrations to the vehicle body and makes the occupants uncomfortable, but also increases the number of times the anti-skid system is operated, increasing the amount of pressurized air consumed, and causing the wheels to skid. Accelerate the progress toward
This has the disadvantage of making anti-skid control difficult.

Therefore, in order to eliminate the above drawbacks, a throttle device is installed on the inlet side of the solenoid valve device that normally supplies pressurized air to the solenoid valve without throttling it, but during anti-skid control, it throttles the pressure supply to the solenoid valve device to a predetermined value. Conventionally, a system has been proposed in which the rise of the brake is delayed under normal conditions, but during anti-skid control, the brake pressure rise speed is optimally controlled by throttling.

However, the conventional throttling device detects the fluid pressure difference between the brake valve and the brake chamber, and when the pressure in the brake chamber decreases to a predetermined value or more than the pressure in the brake valve, a The aperture member was moved forward and backward into the hole, thereby changing the cross-sectional area of the communicating hole, so in order to accurately define the aperture cross-sectional area,
It is necessary to accurately determine the relative positional relationship between the communication hole and the aperture member, which not only requires high processing precision but also makes the mechanism complicated.

In addition, when the brake valve is suddenly operated and the brake pressure rises rapidly, the fluid pressure in the brake chamber increases with a delay compared to the discharge fluid pressure of the brake valve due to piping resistance in the brake system. There is a risk that a pressure difference greater than a predetermined value is generated between the brake valve and the brake valve, and the throttle device malfunctions due to the pressure difference, thereby unnecessarily restricting the rate of pressure increase in the brake chamber.

The present invention was devised in view of the above-mentioned problems, and is equipped with a throttling device that performs a stable and accurate throttling action and does not malfunction even in the event of a sudden rise in brake pressure. The purpose is to provide a pressure control device for brake anti-skid, and its features are as follows:
The above-mentioned throttle device has a main body with a stepped cylinder bored inside, and a cylinder with a membrane that is slidably inserted into the main body, and a brake valve is connected to the outer periphery of the small diameter part via a supply port, and a large diameter hole and A first pressure chamber is connected to the solenoid valve through a throttle hole, a second pressure chamber is connected to the brake chamber at the end of the small diameter portion, and a third pressure chamber is connected to the first pressure chamber through a small hole at the end of the large diameter portion.
a stepped piston forming a pressure chamber;
When the fluid pressure in the pressure chamber is lower than the fluid pressure in the first pressure chamber by a predetermined value or more, the large diameter hole is closed by the piston, and pressurized fluid is supplied to the electromagnetic valve only by the throttle hole. be.

In other words, when the fluid pressure in the brake chamber decreases by more than a predetermined value than the fluid pressure in the brake valve, the large diameter hole is closed by the piston and pressurized fluid is supplied to the solenoid valve only through the throttle hole. By determining the amount of pressure, the throttling effect can be set constant and a stable increase in brake pressure can be obtained at all times.In addition, when the pressure difference between the brake chamber and the brake valve exceeds a predetermined value, the piston increases the Since it is only necessary to close the diameter hole, the structure is simple and does not require dimensional accuracy.Furthermore, a third pressure chamber is provided opposite to the second pressure chamber connected to the brake chamber, and this third pressure Since the chamber is communicated with the first pressure chamber through a small hole, if the pressure of the brake valve suddenly increases, the pressure in the third pressure chamber will increase after the pressure in the first pressure chamber, and the pressure in the first pressure chamber will increase. Since a transient pressure difference is generated between the pressure in the pressure chamber and the pressure in the pressure chamber, even when a transient pressure difference is generated between the first pressure chamber and the second pressure chamber, the piston It will not move and the iris device will not malfunction.

To explain according to the drawings below, 1 is an air reservoir which is constantly compressed at 6 to 9 kg/cr by a compressor (not shown).
The pressure is maintained at fL2.

2 is a brake valve equipped with a brake pedal 3 that is operated by the driver; 4 is a throttle device; 5 is a solenoid valve for shutoff; 6
is a solenoid valve for exhaust, and both solenoid valves form a solenoid valve device.

When both solenoid valves are demagnetized, the plunger 5a of the isolation solenoid valve 5 is pushed upward by the spring 5b and is in a communicating state, and the plunger 6a of the exhaust solenoid valve 6 is pushed down by the spring 6b. Communication with the exhaust port 6C is cut off.

Therefore, the inlet lower and outlet 8 of the solenoid valve device are maintained in a communicating state.

9 is a brake chamber of a wheel brake device.

To explain the aperture device 4 in detail, the main body 41 has a small diameter portion 4.
A stepped cylinder 53 having a 1a1 large diameter portion 41b is provided, and a stepped piston 42 is slidably inserted into the stepped cylinder 53.

A sealing material 43 is attached to the outer periphery of the small diameter portion of the piston 42 that engages with the small diameter portion 41a.
A second pressure chamber 44 formed at the bottom of the cylinder 2 and a first pressure chamber 45 formed between the piston 42 and the large diameter portion 41b of the stepped cylinder 53 are airtightly sealed.

The piston 42 is pressed upward by a spring 46, and its upward movement is restricted by a lid 47 screwed onto the main body 41.

Further, a third pressure chamber 54 formed between the upper end of the large diameter portion of the piston 420 and the lid 47 communicates with the first pressure chamber 45 through a small hole 42a provided in the piston 42.

In addition, the main body 41 is provided with a supply port 48 connected to the brake valve 2, an outlet port 49 connected to the inlet lower of the solenoid valve device, and a control port 50 connected to the outlet 8 of the solenoid valve device. The outlet port 49 and the first pressure chamber 45 communicate with each other through a large diameter hole 51 and a throttle hole 52, and the large diameter hole 51 allows the pressure air supplied from the supply port 48 to be connected to the outlet port 49 without being throttled.
The restricting hole 52 is set to be large enough to send the air to the air outlet 49, and the throttle hole 52 is set so that the pressure air is sent to the air outlet 49 at an optimal charging speed for anti-skid control.

When the piston 42 is in the position shown in the drawing, the supply port 48
and the outlet 49 are connected through a large diameter hole 51 and a throttle hole 52, and the piston 42 descends and the large diameter portion 4
When the large diameter hole 51 is interrupted by the large diameter hole 51, the connection is made only through the throttle hole 52.

A case in which anti-skid control is not required will be explained below.

When a brake pedal force is applied to the brake pedal 3, the brake valve 2 is actuated, and the compressed air is supplied to the supply port 48 of the throttling device 4 in accordance with the brake pedal force, passes through the first pressure chamber 45, and passes through the discharge port 49 to the electromagnetic valve. Supplied to the input lower of the device.

In this state, both the barrier solenoid valve 5 and the exhaust solenoid valve 6 are in a demagnetized state, so the inlet T and outlet 8 of the solenoid valve device are in communication.

Therefore, the pressurized air supplied to the input lower is supplied from the outlet 8 to the brake chamber 9 to apply the brake.

At the same time, the pressurized air at the outlet 8 of the solenoid valve arrangement is also supplied to the second pressure chamber 44 through the control port 50 of the throttle arrangement 4 .

However, since the pressure in the first pressure chamber 45 and the pressure in the second pressure chamber 44 are almost the same, the piston 42
remains pressed upward by the first pressure chamber 4.
The pressurized air 5 passes through the large diameter hole 51 and the throttle hole 52 and is sent out from the outlet 49 without being throttled.

The set tension of the spring 46 is set to a value such that the piston 42 does not move downward due to the differential pressure between the first pressure chamber 45 and the second pressure chamber 44 caused by the frictional resistance of the air flow.

Further, when the brake is suddenly operated, the brake fluid is sent out from the brake valve 2.

When the fluid pressure rises rapidly, a pressure difference that exceeds the set tension of the spring 46 occurs between the first pressure chamber 45 and the second pressure chamber 44 due to the resistance flowing through the pipeline and the delay in pressure transmission.

However, since pressure fluid is supplied to the third pressure chamber 54 through the small hole 42a, the pressure in the third pressure chamber 54 increases with a little delay to the pressure increase in the first pressure chamber 45, and also , when the piston 42 attempts to move downward, the third pressure chamber 5
Since the volume of the chamber 4 increases and acts to lower the pressure in the chamber 54, the piston 42 does not move downward, so even if the brakes are suddenly applied,
The piston 42 does not move downward to close the large diameter hole, and the rate of pressure increase in the brake chamber 9 is not limited.

The brake valve 2 then supplies air at a high enough pressure to the brake chamber 9 for anti-skid control, and when the wheels (not shown) begin to skid, the skid is controlled by the control unit (not shown). A brake pressure release command, that is, an excitation signal is sent to the shield solenoid valve 5 and the exhaust solenoid valve 6.

As a result, the shield solenoid valve 5 is energized, and the plunger 5
At the same time, the exhaust solenoid valve 6 is energized, the plunger 6a is pulled upward, the outlet 8 and the exhaust port 6c are brought into communication, and the brake chamber is closed. 9 pressure air is at exhaust port 6C
As the exhaust increases, the brake pressure decreases and the brakes loosen.

This decrease in brake pressure also occurs in the second pressure chamber 44 via the control port 50 of the throttle device 4.

Since the pressure in the first pressure chamber 45 is maintained at the pressure supplied from the brake valve 2, the pressure in the second pressure chamber 44 becomes lower than the pressure in the first pressure chamber 45, and this pressure difference causes the piston 42 to move. The piston 420 moves downward in the drawing against the tension of the spring 46, closes the large diameter hole 51 with the dog diameter portion 42b, and communicates the first pressure chamber 45 and the outlet 49 only through the throttle hole 52.

When the skid of the wheels is eliminated by loosening the brake, the control unit sends a brake command, that is, a degaussing signal, to the solenoid valve device, and the solenoid valve 5 for the shutoff cylinder and the solenoid valve 6 for exhaust are demagnetized, and each plunger is demagnetized. 5a and 6a are returned to their original states, ie, the state shown in the figure, by springs 5b and 6b, and the exhaust port 6c is closed, so that the lower inlet and the outlet 8 communicate with each other.

Therefore, the pressurized air from the brake valve 2 is supplied to the brake chamber 9 again, and the brake pressure increases.

However, as described above, since the dog diameter hole 51 of the throttle device 40 is blocked by the large diameter portion 42b of the piston, pressurized air is supplied only through the throttle hole 52, and the rate of increase in brake pressure is appropriately limited. has been done.

This pressure increase causes the wheels to skid again.
The brake pressure decreases again by the same operation as described above.

Further, when a brake holding command is given from the control unit, only the solenoid valve 5 for the closing cylinder is energized and communication between the inlet lower and the outlet 8 is cut off, and the brake pressure in the brake chamber 9 is kept constant.

Then, the anti-skid control is completed and the first pressure chamber 45 and the second
When the pressure in the pressure chamber 44 becomes the same, the piston 42 is pushed back upward by the spring 46, the large diameter hole 51 opens again, and the throttling action of the throttling device 4 is stopped.

As is clear from the above explanation, the present invention is designed so that when the fluid pressure in the brake chamber decreases by more than a predetermined value than the fluid pressure in the brake valve, the large diameter hole is closed by the piston and pressurized fluid is supplied to the solenoid valve only through the throttle hole. Therefore, the rate of pressure rise in the brake chamber during anti-skid control is uniquely set by the cross-sectional area of the throttle hole, making it possible to always obtain a stable brake pressure rise.
When the pressure difference between the brake valve and the brake chamber exceeds a predetermined value, it is only necessary to close the large diameter hole with the piston, so the structure is simple and does not require dimensional accuracy. Since the third pressure chamber is provided opposite to the third pressure chamber, it is possible to obtain an excellent effect that malfunction does not occur even when the brake valve is suddenly operated and the brake pressure rises rapidly.

Although the embodiment described a solenoid valve device consisting of a solenoid valve for a solenoid valve and a solenoid valve for exhaust, the present invention can also be applied to a two-position single solenoid solenoid valve that takes two positions, supply and exhaust. effect can be obtained.

[Brief explanation of the drawing]

The drawing is a sectional view showing an embodiment of a brake pressure control device embodying the present invention. 2... Brake valve, 4... Throttle device, 5... Solenoid valve for cylinder, 6... Solenoid valve for exhaust, 41... Main body,
42... Piston, 44... Second pressure chamber, 45...
・First pressure chamber, 46... Spring, 51... Large diameter hole, 52... Calibration hole, 53... Stepped cylinder, 54...
...Third pressure chamber.

Claims (1)

[Scope of utility model registration request] In the communication path connecting the brake valve and the brake chamber,
A solenoid valve that opens and closes according to commands from a control unit is provided between the solenoid valve and the brake valve, and when the solenoid valve operates and the fluid pressure difference between the brake valve and the brake chamber exceeds a predetermined value, both In an anti-skid device including a throttle device that throttles a communication path between valves, the throttle device includes a main body having a stepped cylinder bored therein;
A first pressure chamber is slidably inserted into the cylinder with an accidental discharge, and is connected to the brake valve via a supply port on the outer periphery of the small diameter portion, and is also connected to the electromagnetic valve via a dog diameter hole and a throttle hole. , a stepped-shaped piston forming a second pressure chamber connected to the pre-pressure chamber at the end of the small diameter part and a third pressure chamber communicating with the first pressure chamber via the small hole at the end of the large diameter part, When the fluid pressure in the second pressure chamber is lower than the fluid pressure in the first pressure chamber by a predetermined value or more, the large diameter hole is closed by the piston, and pressurized fluid is supplied to the electromagnetic valve only by the throttle hole. Pressure control device for anti-skid brakes on vehicles.