JPS6038240A - Braking hydraulic pressure control valve device for vehicle - Google Patents

Abstract

PURPOSE:To make sure of safety in time of trouble happening in a device, by setting up a bypass oil passage installing a safety valve side by side, which bypasses a valve mechanism selecting both interconnection and interception states between an oil passage at the output side of a master cylinder and an oil passage leading to a wheel brake. CONSTITUTION:A valve box 5 is installed in position between an oil passage 2 at the output side of a master cylinder M and an oil passage 4 leading to a wheel brake 3 of a wheel brake B, and a valve mechanism 6 installed inside this valve box 5 is controlled by a hydraulic control device 7, selecting both interconnection and interception states between both oil passages 2 and 4. In this case, a bypass passage 37 bypassing the valve mechanism 6 is additionally installed inside the valve box 5, and a safety valve 36 is installed in a point midway in the bypass passage 37. The safety valve 36 makes a piston 39 go to the right by means of a spring 2 and open the valve whereby hydraulic fluid out of the master cylinder M is fed to the wheel cylinder 3 by way of the bypass passage 37.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a brake hydraulic control valve device for a vehicle, in particular, a hydraulic pressure control valve device that is spring-biased toward one end in the axial direction in the middle of an oil path connecting an output port of a mask cylinder and a wheel brake. A cylinder portion in which a piston is slidably fitted is provided, and a control hydraulic chamber defined between one end of the piston and one end of the cylinder portion includes:
Hydraulic control means is connected between the other end of the piston and the other end of the cylinder portion, and operates to supply pressure oil during normal times and release the pressure oil when the wheels are about to enter the locked state. An output hydraulic chamber communicating with the wheel brake is defined, and an input hydraulic chamber formed in the piston to constantly communicate with the output port is connected to the output hydraulic chamber in response to movement of the piston toward the one end. The present invention relates to a brake hydraulic control valve device for a vehicle that is provided with a valve mechanism that operates to shut off a state.

Conventionally, in such a brake hydraulic control valve device for a vehicle, hydraulic pressure from a hydraulic control means acts on the control hydraulic chamber, and the piston is displaced toward the other end, so that the valve mechanism remains open.
When the brake is operated, the brake hydraulic pressure from the output port of the mask cylinder acts on the wheel brake to obtain braking force. When the wheels are about to lock, the hydraulic pressure in the control hydraulic chamber is released, so the piston is moved to one end. As the valve mechanism closes, the hydraulic pressure in the output hydraulic chamber decreases and the braking force is weakened, thereby preventing the wheels from becoming locked.

However, if a hydraulic source such as a hydraulic pump in the hydraulic control means malfunctions and the supply of pressure oil to the control hydraulic chamber is stopped during normal times, and the hydraulic pressure in the control hydraulic chamber becomes extremely low, the piston will be displaced to one end. Since the valve mechanism remains closed, even if the brakes are operated, brake hydraulic pressure does not act on the wheel brakes and no braking force is obtained.

The present invention has been made to solve such conventional technical problems, and provides a brake hydraulic control valve device for a vehicle that allows brake hydraulic pressure to act on wheel brakes despite a failure of the hydraulic control means. The purpose is to provide

Hereinafter, embodiments of the present invention will be explained with reference to the drawings.
First, in FIG. 1, output port 1 of mask cylinder M
A valve surface 5 is provided between the oil passage 2 extending from the wheel brake B and the oil passage 4 leading to the wheel cylinder 3 of the wheel brake B. A valve mechanism 6 provided in this valve surface 5 allows both oil passages 2
, 4 are switched between communicating and blocking states, and the operation of the valve mechanism 6 is controlled by the hydraulic control means T.

The valve surface 5 is fixed to a proper position on the vehicle body, and a cylinder portion 8 is provided inside the valve surface 5, which is closed at both ends and extends in a straight line. A piston 9 is movably slid into the cylinder portion 8 , and a control hydraulic chamber 11 is defined between one end wall 10 of the cylinder portion 8 and one end of the piston 9 . An output hydraulic pressure chamber 13 is defined between the other end wall 12 and the other end of the piston 9 .

A connecting oil passage 14 that communicates with the control hydraulic chamber 11 and an outlet oil passage 15 that communicates with the output hydraulic chamber 13 are bored in the valve surface 5.
The hydraulic pressure control means 7 is connected to the connecting oil passage 14, and the oil passage 4 communicating with the foil cylinder 3 is connected to the outlet oil passage 14.

Inside the piston 9, an input hydraulic pressure chamber 16 is provided approximately at the center thereof, and at the other end of the piston 9, a spring chamber 17 that is open toward the end wall 12 is bored. Moreover, a valve hole 18 is formed in the piston 9 concentrically connecting the input hydraulic pressure chamber 16 and the spring chamber 17, and an annular groove 19 is formed in the outer periphery of the piston 9.
An oil passage 20 is bored to communicate the input hydraulic chamber 16 and the annular groove 19.

In addition, an inlet oil passage 21 is bored in the valve surface 5 and is always in communication with the annular groove 19 regardless of the position of the piston 9. Connected. Further, a plurality of seal members 22 are attached to the outer circumferential surface of the piston 19, which perform a sealing function by slidingly contacting the inner circumferential surface of the cylinder portion 8.

A support rod 23 that can project from the spring chamber 17 of the piston 9 into the input hydraulic pressure chamber 16 through the valve hole 18 is integrally provided on the other end wall 12 of the cylinder portion 8.
The length of 3 is such that when the piston 9 is most displaced toward the other end of the cylinder portion 8 (left side in FIG. 1), its tip reaches the input hydraulic chamber 1.
It is set to within 6. In the output hydraulic chamber 13, a coil spring 24 surrounding the support rod 23 is attached to the end wall 1.
2 and the piston 9, this coil spring 24
urges the piston 9 toward one end thereof.

The valve mechanism 6 includes a spherical valve body 25 housed in the input hydraulic pressure chamber 16, a conical valve seat 26 provided at a stepped portion between the input hydraulic pressure chamber 16 and the valve hole 18, and a valve body 25 that serves as a valve. It is composed of a conical coil spring 27 that urges toward the seat 26 and the support rod 23. In this valve mechanism 6, when the piston 9 is displaced to one end side, that is, to the right side in FIG.
5 is seated on the valve seat 26 by the conical coil spring 27, and the valve hole 18 is closed, and conversely, the piston 9 is displaced to the other end, that is, to the left in FIG. 16, the valve body 25 is forcibly separated from the valve seat 26 by the support rod 23, and the valve hole 18 is opened.

The hydraulic control means 1 includes an oil tank 28, a hydraulic pump 29 that pumps pressure oil from the oil tank 2B, a relief valve 30, an accumulator 31, and an on-off valve 32 that is open during normal times.
and an on-off valve 33 which is closed during normal times. The supply oil FI 6341'i is connected to the outlet of the hydraulic pump 29, and is connected to the connection oil path 12 with an on-off valve 32 provided therebetween. A return oil passage 35 is branched from the supply oil passage 34 between the on-off valve 32 and the connection oil passage 12.
An on-off valve 33 is provided in the middle. Further, in the oil supply path 34, an accumulator 31 and a relief valve 3o are connected between the on-off valve 32 and the hydraulic pump 29. Such a hydraulic control circuit 1 is conventionally known, and the hydraulic pump 29 is always driven when the vehicle is operating, and when a wheel speed sensor (not shown) detects that the wheels are about to lock. , the on-off valve 32 is closed and the on-off valve 33 is opened.

According to the present invention, the safety valve 3 is attached to the valve surface 5 in order to apply the brake hydraulic pressure from the output port 1 of the mask cylinder AI to the foil cylinder 3 regardless of a failure of the hydraulic control means 7.
6 is provided. That is, a bypass oil passage 37 that bypasses the valve mechanism 6 is provided in the valve surface 9-5, connecting the annular groove 19 and the outlet oil passage 15, and a safety valve 36 is disposed in the middle of this bypass oil passage 37.

The safety valve 36 includes: - a sliding hole 38 that extends linearly and is closed at both ends; a piston 39 that slides into the sliding hole 38;
A hydraulic action chamber 40 defined between one end of the sliding hole 38 and one end of the piston 39; a spring chamber 41 defined between the other end of the sliding hole 38 and the other end of the piston 39;
a coil spring 42 housed in the piston 39 and biasing the piston 39 toward one end (right side in FIG. 1); a valve hole 43 formed at the other end of the sliding hole 38; It consists of a valve body 44 that can open and close the hole 43.

A connecting oil passage 45 communicating with the hydraulic pressure chamber 40 is bored in the valve surface 5, and this connecting oil passage 45 has a connection oil passage 45 located upstream of the on-off valve 32 of the supply oil passage 34 in the hydraulic control means 7 by -10=. A branch oil passage 46 branched from the portion is connected. The piston 39 is integrally provided with a support portion 47 that protrudes like a rod from the end surface facing the spring chamber 41.
A valve body 44 is integrally fixed to the tip of the valve 7 . A portion 37a on the first flow side of the bypass oil passage 37 communicates with the side portion of the spring chamber 41, and a portion 375 on the downstream side communicates with the valve hole 43. Further, the coil spring 42 surrounds the support portion 47 and is interposed between the other end of the slide hole 38 and the piston 39.

Next, to explain the operation of this embodiment, it is assumed that the hydraulic pump 29 of the hydraulic control means 7 fails and the hydraulic pressure in the control hydraulic chamber 11 drops extremely. In this case, the oil pressure in the hydraulic chamber 40 of the safety valve 36 has naturally decreased, and the pistons 9, 39 have been displaced to the right end in FIG. 1 by the coil springs 24, 42. When the brake pedal P is pressed to perform a brake operation in this state, the valve mechanism 6 is closed, but the safety valve 36 is open, so the brake oil pressure from the output port 1 of the mask cylinder AI is , the oil passage 2, the inlet oil passage 21, the annular groove 19, the bypass oil passage 31, the outlet oil passage 15, and the oil passage 4. Brake function is ensured.

Moreover, in this way, the control hydraulic chamber 11 and the hydraulic action chamber 4
When the oil pressure at 0 drops extremely, the pistons 9 and 39 are immediately displaced to the right end in Fig. 1 by the coil springs 24 and 42, so when the brake is operated afterwards, each piston 9 and 39 moves to the right. The number of invalid strokes does not increase by moving to .

When the hydraulic control means 7 is operating normally, the hydraulic pressure acts on the hydraulic chamber 40 during normal times, pushing the piston 39 to the left, and the valve hole 43 is blocked by the valve body 44.
The piston 9 and the valve mechanism 6 operate in a conventional manner without the safety valve 36. That is, during normal times, hydraulic pressure acts on the control hydraulic chamber 11 and the piston 9 is suppressed and displaced to the left in FIG. Pedal P
By stepping on the brake cylinder AI, the brake oil pressure from the mask cylinder AI acts on the wheel cylinder 3 of the wheel brake B through the valve hole 18 to obtain a braking force. Also, the wheels are locked.
When this happens, the on-off valve 32 is closed and the on-off valve 33 is opened, so the oil pressure in the control hydraulic chamber 11 decreases, and the piston 9 is displaced to the right in FIG. 1 by the force of the coil spring. Therefore, the valve body 25 is seated on the valve seat 26, and the volume of the output hydraulic pressure chamber 13 becomes enormous. Therefore, foil cylinder 3
The hydraulic pressure inside the brake system decreases, weakening the braking force and preventing the wheels from locking up. At this time, hydraulic pressure is acting on the hydraulic chamber 40 of the safety valve 13-36, and the safety valve 36 remains closed.

In the above embodiments, explanations have been given for a single wheel brake B, but the present invention can also be applied to control a pair of wheel brakes at the same time, and in this case, as shown in FIG. , the piston 9, the valve mechanism 6, etc. are arranged symmetrically with respect to the single control hydraulic chamber 11 arranged in the center, and the piston 39, the valve body 44, etc. are arranged symmetrically with respect to the single hydraulic action chamber 40 arranged in the center. It is sufficient to set it in

As described above, according to the present invention, a bypass oil passage is provided that bypasses the valve mechanism and connects the mask cylinder and the wheel brake, and in the middle of the bypass oil passage, the bypass oil passage is controlled by hydraulic pressure from the hydraulic control means. Since a safety valve is provided which is biased in the direction of closing IF and also biased with a spring in the direction of opening the bypass oil passage, even if the hydraulic pressure 14-control means fails, the bypass oil passage is opened, and therefore the brake oil pressure is applied to the wheel brakes. can be made to work.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of one embodiment of the invention, and FIG. 2 is a longitudinal sectional view of another embodiment of the invention. DESCRIPTION OF SYMBOLS 1... Output boat, 2, 4... Oil path, 6... Valve mechanism, 7... Hydraulic control means, 8... Cylinder part, 9...
... Piston, 11... Control hydraulic chamber, 13... Output hydraulic chamber, 16... Input hydraulic chamber, 36... Safety valve, 3
7...Bypass oil path 15-

Claims (1)

[Claims] A cylinder part is provided in the middle of the oil passage connecting between the output port of the mask cylinder and the wheel brake, and a piston slidingly engaged with a spring biased toward one end in the axial direction is provided, and one end of the piston and one end of the cylinder part are connected to each other. A hydraulic control means is connected to a control hydraulic chamber defined between the piston and the piston, which operates to supply pressurized oil during normal times and release the pressurized oil when the wheels are about to enter the locked state. An output hydraulic chamber communicating with the wheel brake is defined between the end and the other end of the cylinder part, and an input hydraulic chamber is formed in the piston to constantly communicate with the output port. In a vehicle brake hydraulic control valve device provided with a valve mechanism that operates to cut off communication with an output hydraulic chamber in response to movement toward one end, the valve mechanism is bypassed between the mask cylinder and the wheel brake. A bypass oil line is connected to
A safety valve is provided in the middle of the bypass oil passage, which is biased in the direction of closing the bypass oil passage by hydraulic pressure from the hydraulic pressure source of the hydraulic pressure control means, and is spring-biased in the direction of opening the bypass oil passage. A vehicle brake hydraulic control valve device characterized by: