JPS60257B2 - Brake fluid pressure control system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a two-system brake fluid pressure control device, and more specifically, to a brake fluid pressure control device for an automobile having two P valves arranged in series. This relates to a brake fluid pressure control system incorporating a brake fluid pressure control system.

A brake fluid pressure control device that controls the fluid pressure of each brake system using two P valves and has a function of increasing the breaking point of the brake fluid pressure of other systems when one system is damaged has not been provided in the past. However, these devices have the drawback of being large and having a complicated structure.

Also, it is desirable that the breaking point of each P valve increases in proportion to the load of the car, but since the spring of the previous P valve was limited to a constant load, the "fluid rises according to the load." In order to change the indentation point, it is necessary to use a load response valve, a G valve, etc., but this requires a separate spring, which also requires a large number of components.The purpose of the present invention is to To provide a brake fluid pressure control system incorporating a P valve and a G valve, which has a small and simple structure, has the same performance as the conventional system, and eliminates the problems caused by the above problems.

Hereinafter, embodiments of the present invention will be described with reference to the drawings, and common reference numerals will be used for all common items. In FIG. 1, reference numeral 100 indicates the entire P valve device, and a balance piston 1 is inserted into the cylinder hole 11 drilled in the body Q.
2 is carried in so as to be slidable on the inner wall of the cylinder hole il.

A microphone is provided in the pongee portion 13 approximately in the center of the balance piston 12. The sensing rod 15 of the switch 14 is in contact, and as the balance piston 12 moves left and right, the sensing rod 15 is pushed up by the tapered portion 16 of the balance piston 12, turning on the microswitch 14. The warning light 17 is turned on. A master cylinder 19 connected and engaged with the brake pedal 18 is connected to a first supply pipe 20 via a first supply pipe 20.
The liquid is communicated with the inlet boat 21 and the second inlet boat 23 via the second supply pipe 22, respectively.

Thus, the first inlet boat 21' communicates liquid with the third liquid chamber 28 via the first liquid chamber 24 and the first liquid passage 26.

Similarly, the second inlet boat 23 communicates with a fourth liquid chamber 29 via a second liquid chamber 25 and a second liquid passage 27. The third
The liquid chamber 28 is provided with a third IP valve 30, and the fourth liquid chamber 29 is provided with a third IP valve 31, respectively. In the conventional P valve, springs for biasing in the opening direction are individually and integrally provided, but in this embodiment, only one spring is provided separately as will be described later.

The first IP valve 39 and the second IP valve 31 are arranged in series to operate synchronously in the same direction.

That is, the first IP valve 30 and the second valve 31 can be arranged in series by bringing the tip end surface 33 of the piston 32 of the first IP valve 30 into contact with the rear end surface 35 of the piston 34 of the third IP valve 31. It is set up. Further, the specifications of the IP valve 3Q and the IP valve 31 are made the same so that they operate synchronously in the same direction by sharing the urging force as described later.

Thus, the spring 36 comes into contact with the rear end surface 37 of the piston 32 of the first IP valve 30 and biases the younger IP valve 30 and the first valve 31 in the opening direction via the retainer 38. That is, one spring biases the two P valves in the opening direction. Moreover, the third liquid chamber 28
passes through the first exit boat 39 and the liquid lotus, and the first exit boat 3
Brake fluid is transmitted from 9 to each rear wheel RW.

Similarly, the brake fluid discharged from the fourth fluid discharge chamber 29 is
It is transmitted to each rear wheel RW via the output port 40.

A conduit 41 branching off from the first supply pipe 20 is in liquid communication with the G valve device 200, and from the device 200, the liquid is communicated via a conduit 42 to the boat 43 of the P valve device 100. The hydraulic pressure introduced into the boat 43 acts on a slidable piston 44 which abuts and engages one end of the spring 36 which biases the first and second valves 30,31. still,
The G valve device 200 has a well-known configuration, and includes a G valve that rolls within a chamber 48 of a housing 45 that is disposed at a certain depression angle in the direction of vehicle bran running in response to deceleration.
A ball 46 is supported and arranged on a supporter 49.

5 G ball 4 is installed on the valve seat installed on the inner wall of the housing.
6 is seated, the outlet 47 and the chamber 48 are cut off, and the liquid flow to the conduit 42 is cut off.

In other words, the hydraulic circuit bypassed via conduit 41, G-valve device 200 and conduit 42 provides a pilot pressure for compressing spring 36. The effects of the above configuration shown in FIG. 1 will be explained.

When the brake pedal turtle 8 is depressed when the load is small, brake fluid pressure proportional to the depression force is transmitted from the master cylinder turtle 9 to the first inlet boat 21' via the first supply pipe 28. Further, the brake fluid pressure is increased from the first inlet boat 21 to the first fluid chamber 24 to the first fluid passage 26.
, third liquid chamber 28, third IP valve 38, first outlet boat 3
It is transmitted to each Lyahuir RW through the vines. Similarly, the brake fluid pressure transmitted to the second supply pipe 22 is applied to the second inlet boat 23, the second fluid chamber 25, the second fluid passage 27, and the fourth fluid chamber 25.
The 9th to 9th valves are transmitted to each rear wheel RW via the valve 31 and the second outlet boat 40.
Both valves 31 and 0 are biased in the opening direction by the spring 36 with the same force, and since both are of the same standard, the force biased in the opening direction by the brake fluid pressure is also the same.

Therefore, the relationship between the brake fluid pressure (master cylinder fluid pressure) at the first entrance boat 21 or the second entrance boat 22 and the brake fluid pressure (rear wheel fluid pressure) at the first exit boat 39 or the second exit boat 40 is , straight line (a-b') in Figure 2
As shown in FIG. set by the control fluid within.

When the load is large, the bending point a', as shown by the straight line (a'-b') in FIG. 2, is due to the combination of the conventionally known G valve characteristics and P valve characteristics. Next, a case where either the first supply pipe 20 or the second supply pipe 22 is damaged will be considered.

In either case, the balance piston 12 moves toward the fluid chamber where the brake fluid pressure is no longer applied, and as a result, the sensor turtle 5 detects the taper part 1 of the balance piston 12.
6, the microswitch 14 is turned on and the warning light 17 is turned on. This allows the driver to know if the brake system is damaged. Now, the operation of the first valve 31 when the first supply pipe 20 is damaged will be considered as follows. First, since the brake fluid pressure in the third fluid chamber 28 is zero, the only force that forces the younger brother to close the valve 31 against the spring 36 is the brake fluid pressure in the fourth fluid 29.However, Under normal conditions, the sum of the brake fluid pressure in the third fluid chamber 28 and the brake fluid pressure in the fourth fluid chamber attempts to close the IP valve 30 and IP valve 31 against the spring 36. In this case, in order to resist the force of the spring 36 and close the fourth valve 31, the brake fluid pressure in the fourth fluid chamber 29 is required to be twice that of the normal brake fluid pressure.

Therefore, the characteristic of the valve 31 is the straight line (a-
c-d). In this case, of course, the G valve device 20 does not operate. Conversely, if we consider the operation of the IP valve 3Q when the second supply pipe 22 is damaged,
In this case as well, using the same concept as in the previous case, the third IP valve 30 can be closed against the spring 36' only when the brake fluid pressure in the third fluid chamber 28 becomes twice the normal pressure.

However, due to damage to the system on one side, the braking performance is poor with only the normal braking action, so the G valve device 280
The rolling of the ball 46 is delayed. The hydraulic pressure introduced into the inlet port 43 increases by that amount, and the amount of movement of the piston 44 is slightly larger than that under normal conditions, compressing the spring 36 and raising the bending point by that amount. In short, if one of the supply pipes breaks, the brake fluid pressure in any of the fluid chambers communicating with that supply pipe becomes zero, and the area exposed to brake fluid during normal operation is halved in this case. The brake fluid pressure required to close either P-valve against the spring doubles, or even more.

As is clear from the above explanation, according to the present invention, if one of the supply pipes is damaged, a warning light is turned on to notify the driver of this fact, and the turning point of the P valve is raised to more than twice the normal value. It is possible to maintain stable running and also obtain braking performance that responds to the load, which is a characteristic of the G valve.

3 shows an embodiment in which the arrangement of the spring 36 in FIG. energizing spring 13
6a, and further a spring tendril 36 that biases between the piston 144 and the left end of the piston 32 in a direction that expands both.
b between the piston turtle 44 and the inner wall of the housing.
44 is provided with spring means 136 each having a spring tendril 36c stretched thereon.

The effect of this embodiment is the spring 36 in the military diagram.
is the same as As described above, in the present invention, the P valve and the G valve are operationally incorporated into this brake system, without impairing the original performance of the P valve and the original performance of the G valve. By generating a hydraulic pressure that is more than twice the brake fluid supply under normal conditions even when there is a hydraulic pressure deficit in the brake system, a brake hydraulic pressure control system with extremely high safety and good braking performance is constructed.

[Brief explanation of drawings]

Fig. 2 is a brake fluid pressure control system diagram showing an embodiment of the present invention, Fig. 2 is a brake characteristic diagram according to the invention, and Fig. 3 is a partial sectional view showing a modification of the P valve device 100 shown in Fig. . 30: iP valve, 3i: wave valve 2 crab 0: G valve device, 36,136: spring. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1 A first P valve having a first piston and disposed in one brake system, and a second P valve having a second piston and disposed in the other brake system are connected in series so as to operate synchronously in the same direction. A G valve is arranged between the first P valve and the master brake cylinder in the one-way brake system, and means is further arranged to bias both the P valves in the opening direction by contacting only the first piston. A brake fluid pressure control system characterized in that a fluid controlled by the G valve acts on the urging means.