JPS5850901B2 - anti-strain - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention uses the power pressure of a hydraulic brake booster that assists braking force with hydraulic pressure in response to the brake pedal depression force as an input signal pressure, and generates and achieves hydraulic pressure according to the pressure. The present invention relates to a type of anti-skid control device that utilizes the hydraulic pressure as power pressure for a hydraulic actuator that reduces wheel cylinder pressure to prevent wheel skidding.

This system eliminates the disadvantages of anti-skid devices that apply power pressure using wheel cylinder pressure as an input signal, such as increased fluid loss in the braking system and the complicated separation structure for dissimilar fluids between brake fluid and power oil. In conventional anti-skid control devices, the valve that controls the power pressure and the valve that controls the actuator according to the skid condition are generally constructed separately, which is disadvantageous in terms of cost. , it was also structurally complex.

The present invention provides a device that eliminates the above drawbacks,
The feature is that the ratio between the power pressure of the booster and the power pressure for operating the actuator is changed depending on the anti-skid condition, thereby increasing or decreasing the power pressure to operate the actuator.

An embodiment of the present invention device will be described below according to the drawings.
In Fig. 1, 1 is a mask cylinder, 2 is a front wheel wheel cylinder that communicates with the mask cylinder 1, 3 is a rear wheel wheel cylinder, 4 is an actuator body, 5 is a sensor that detects wheel locking, and 6 is a 7 is a pump, 8 is a hydraulic brake booster, 9 is a power steering device;
10 is a brake pedal, 11 is a reservoir, 12 is a safety valve for supplying mask hydraulic pressure to the wheel cylinder to ensure brake operation when the power source is lost, and can be seated on a valve seat 13 or 14; 15 is a piston, as shown in the figure. Safety valve 12 is on the right side
16 is a spring retainer, the left side of which is in contact with the safety valve 12, 17 is a spring that constantly biases the spring retainer 16 to the left in the diagram;
18 is a cut valve that opens and closes communication between the mask cylinder and the rear wheel cylinder 3 without attaching or detaching it to the valve seat 19; 20 is a pressure reducing piston having a pressure-receiving cross-sectional area A1; the right end of the piston is in contact with the cut valve 18; 21 22 is a power piston having a pressure-receiving cross-sectional area A2; 23 is a control valve; 24 is a power pressure detection piston having a pressure-receiving cross-sectional area A3; 25 is a pressure-receiving cross-sectional area A4; 26 is a spool having a pressure-receiving cross-sectional area A5, 27 is a weak spring that always urges the power piston 25 to the left in the drawing, 28 is a weak spring that always urges the spool 26 to the right in the drawing, and 29 is a weak spring that always urges the spool 26 to the right in the drawing. The orifice 30 is a nozzle, and 31 is a plunger, which closes the nozzle 30 by the upward biasing force of a spring 33 when the solenoid coil 32 is not energized.

34, 35, 36, 37, 38 and 39 are chambers, 40.4
1 and 42 are brake pipes.

43.44, 45 and 46 are brake passages, 47.48
, 49, 50 51, 52 and 53 are power pressure pipes, 54
, 55, 56, 57, 58, 59 and 60 are power pressure passages.

Next, in Fig. 2, the A diagram is a characteristic diagram showing the relationship between the mask cylinder pressure and the power pressure of the brake booster, and the B diagram is a characteristic diagram showing the relationship between the brake booster power pressure and the actuator when the nozzle 30 is fully opened. A characteristic diagram showing the relationship between the power pressure (power pressure) and the C diagram shows the power pressure of the booster and the power pressure (power pressure) to the actuator when the nozzle 30 is closed.
The D diagram is a characteristic diagram showing the relationship between the power pressure to the power piston 22 and the brake oil pressure to the decompression piston 20, and the F diagram is the characteristic diagram showing the relationship between the power pressure to the power piston 22 and the brake oil pressure to the decompression piston 20. The F diagram shows the relationship between the power pressure to the power piston 22 and the brake oil pressure to the pressure reducing piston 20 when the nozzle 30 is fully open. The characteristic diagram showing , and the relational expressions of the above B, C and D diagrams are as follows.

However, frictional resistance is ignored.

That is, the relational expressions of the B, C, and D diagrams are as follows: PAB, PAc, PAD... Power pressure (power pressure) to the actuator PPB, PPO...・Booster power pressure PBD ・・・・・・Brake pressure PCB, Pcc, PcD ・・・・・・・・・Constant determined by spring force, etc. In the above configuration, explain its action. do.

First, regarding the normal braking operation, the nozzle 30 is normally operated by the spring 33 acting on the plunger 31.
It is closed by the urging force on the upper blade shown in the figure.

Therefore, when the pedal 10 is depressed now, the discharge flow that was flowing from the pump 7 to the pipe 47 → passage 55 → passage 56 → pipe 49 → brake booster 8 → pipe 51 → power steering device 9 → pipe 52 → reservoir 11 is throttled between the pipe 49 and the pipe 51, and the upstream pressure (power pressure) of the booster 8 increases.

This power pressure acts on the chamber 39 via the pipe 48 and the passage 54 to push the piston 24 to the left in the drawing, and this force pushes the spool 26 to the left in the drawing.

Therefore, the discharge flow from the pump 7 is throttled between the passage 55 and the passage 56 by the leftward movement of the spool 26, and hydraulic pressure is generated. It acts on

At this time, since the nozzle 30 is closed as described above, the chambers 3T and 38 are balanced, and the hydraulic pressure to the piston 25 and the power pressure of the booster to the piston 24 are balanced, so the actuator power from the passage 59 to the chamber 36 is The pressure (power pressure) increases as shown by the C diagram in FIG.

First, the pressure in the mask cylinder 1 increases as shown by the A diagram in FIG. Cylinder 2 and pipe 41
It acts on the pressure reducing piston 20 via → passage 43 → cut valve 18 → chamber 35.

The pressure (brake pressure) that can be maintained in the pressure reducing piston 20 by the power pressure (power pressure) acting on the power piston 22 is given by the D diagram in FIG. 2, and the power pressure when the nozzle 30 is closed is , as mentioned above, is given by the C diagram in Fig. 2, and the relationship between power pressure and brake pressure at this time is given by the E diagram in Fig. 2, that is, the D diagram is better than the E diagram. Since it is in the horizontal position, the pressure reducing piston 20 is in the illustrated position, and the cut valve 18 is disengaged from the valve seat 19.

Further, the pressure of the booster 8 acts on the pipe 50 → the passage 60 → the chamber 34 → the piston 15, and presses the safety valve 12 against the biasing force of the spring 17 to seat it on the valve seat 13.

Therefore, the hydraulic pressure from the mask cylinder 1 acts on the gap between the cut valve 18 and the valve seat 19 -> the chamber 35 -> the passage 45 -> the gap between the safety valve 12 and the valve seat 14 -> the passage 46 -> the pipe 42 -> the rear wheel wheel cylinder 3 .

Next, regarding the anti-skid control operation, first, the pressure reduction effect is determined from the output of the sensor 5, and when the wheels are locked or are about to lock due to overbraking, the computer 6
outputs the skid control activity, causes a specified current to flow through the solenoid coil 32 to excite it, attracts the plunger 31 to the lower blade shown in the figure against the biasing force of the spring 33, and the nozzle 3
0 is opened, the oil pressure in the chamber 38 is transferred to the reservoir 11 via the nozzle 30 and the pipe 53, and the pressure in the chamber 38 decreases depending on the degree of opening.

When the degree of opening increases and the pressure in the chamber 38 becomes approximately atmospheric pressure,
The only pressure acting on the spool 26 is the oil pressure in the chamber 37.

The spool 26 is balanced by the oil pressure in the chamber 37 and the power pressure of the booster 8 to the piston 24.

Booster power pressure and actuator power pressure at this time (
Since the relationship between power pressure and brake pressure is given as shown in the B diagram in Figure 2, the relationship between the power pressure and brake pressure at this time is given by the F diagram in Figure 2, which is better than the D diagram. Since line F is downward (i.e., sufficiently downward to reduce brake pressure and avoid locking or near-locking of the wheels), the pressure reducing piston 20 moves to the left in the diagram, and the cut valve 18 It is pushed to the left in the figure by the biasing force of the spring 21 and is seated on the valve seat 19.

Therefore, the supply of mask cylinder pressure to the rear wheel wheel cylinder 3 is cut off, and the volume of the chamber 35 is expanded by the leftward movement of the pressure reducing piston 20, and the oil pressure in the chamber 35 is lowered to reduce the pressure of the brake. .

Next, talking about the pressure recovery effect, when the current to the solenoid coil 32 decreases according to a command from the computer 6, the plunger 31 is moved to the nozzle 3 by the action of the spring 33.
Close 0.

Therefore, when the amount of closing is completed, the state is the same as when the brake is normally applied, and the pressure reducing piston 20 moves to the right, disengaging the cut valve 18 from the valve seat 19 and supplying the hydraulic pressure of the mask cylinder 1 to the foil cylinder 3. .

In addition, in the above, if the opening degree of the nozzle 30 is changed according to the current value to the solenoid coil 32, the pressure in the chamber 38 can be arbitrarily changed, and the power pressure (power pressure), that is, the wheel cylinder oil pressure can be arbitrarily changed. Variable linear control is also possible.

Also, during normal braking, the power pressure acting on the chamber 34 presses the piston 15 to the right in the figure and seats the safety valve 12 on the valve seat 13. However, when the pump system that is the pressure source is damaged, the spring 17 is The force and the hydraulic pressure on the passage 44 side push the safety valve 12 to the left in the figure, and the safety valve 12 is moved to the valve seat 1.
3, and the passages 43 and 46 are connected to each other without passing through the passage 45, thereby enabling brake manual operation.

As is clear from the above explanation of the structure and operation, the power pressure control valve and the actuator operation control valve are integrated into one unit, resulting in low cost, simple structure, and improved reliability. .

Also, depending on the solenoid control method, on/off control and linear control are possible.

Further, by applying the power pressure of the booster to the power pressure control valve, excellent effects such as improved responsiveness and no loss of braking force can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a diagram illustrating the central longitudinal section of the device of the present invention applied to an automobile braking system, and FIG. 2 is a diagram showing the characteristics of the device of the present invention. 18... Cut valve, 20... Pressure reducing piston, 22... Power piston, 24...
...Power pressure detection piston, 25...Power piston, 26...Spool, 29...
Orifice, 30... Nozzle, 31...
・Plunger, 32...Solenoid coil○

Claims (1)

[Claims] 1. A brake booster that generates brake pressure in a mask cylinder by applying the power pressure generated by brake pedal operation to the brake pedal depression force, and is arranged between the mask cylinder and the foil cylinder and increases the brake pressure of the foil cylinder by the operation of power pressure. actuators that reduce and increase pressure;
first valve means for supplying power pressure to the actuator;
Normally, when the brake is applied, the power pressure of the booster and the power pressure are matched on both sides of the piston to balance the piston, and in the balanced position, the power pressure is applied to the actuator via the first valve means to brake the wheel cylinder. An anti-skid control device which increases pressure and operates a second valve means to reduce power pressure when wheels are locked or about to lock.