JPH06171486A - Fluid pressure adjuster for antiskid system - Google Patents

Abstract

PURPOSE:To solve such a problem that a drop in brake fluid pressure becomes impossible even if a reservoir is filled up with a brake fluid by repeating ups and dawns of the brake fluid pressure in a wheel brake cylinder. CONSTITUTION:A differential pressure response valve 17 allowing a flow of fluid from the side of a brake master cylinder 12 to the side of a solenoid valve 14, a throttle passage 18 related in parallel with this response valve 17, and two check valves CV1 and CV2 being related in parallel with this valve 17 and allowing the flow from the side of the solenoid valve 14 to the side of the brake master cylinder 12 are all installed in an interval between a spot, where a discharge fluid out of a motor-driven pump 16 in a pipeline 13 flows in, and the brake master cylinder 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic pressure adjusting device for an anti-skid device such as an automobile equipped with a hydraulic brake device, and more particularly to a position for interrupting the supply of brake liquid from a brake master cylinder to a wheel brake cylinder. An electromagnetic valve having at least a position that allows the outflow of the brake fluid from the wheel brake cylinder to the reservoir, and an electric pump that returns the brake fluid in the reservoir to the conduit between the brake master cylinder and the electromagnetic valve. The present invention relates to a hydraulic pressure adjusting device for an anti-skid device provided with.

[0002]

2. Description of the Related Art In this type of brake fluid pressure adjusting device, when adjusting the brake fluid pressure in the wheel brake cylinder, the brake fluid that has flowed out of the wheel brake cylinder into the reservoir is actuated by an electric pump to the brake master cylinder side. It is desirable to reduce the kickback phenomenon of the brake pedal that occurs when the brake pedal is returned. As a conventional technique for dealing with this with a simple configuration, there is one described in Japanese Utility Model Laid-Open No. 1-65746. In this configuration, the flow from the brake master cylinder side to the solenoid valve side is not restricted between the location where the discharge liquid of the electric pump flows into the pipeline and the brake master cylinder, but a valve that throttles the reverse flow is provided. A device is provided.

[0003]

However, in the above-mentioned prior art, since the flow rate of the brake fluid discharged from the electric pump returning to the brake master cylinder is small, the brake fluid pressure in the wheel brake cylinder is repeatedly decreased and increased. There is a problem that the brake fluid accumulates in the reservoir and finally the reservoir becomes full, so that the brake fluid pressure in the wheel brake cylinder cannot be lowered.

An object of the invention of this application is to solve the above problems with a simple structure.

[0005]

In order to solve the above-mentioned technical problems, the invention of this application is directed to a position at which the supply of brake fluid from the brake master cylinder to the wheel brake cylinder is cut off, and a brake from the wheel brake cylinder to the reservoir. A liquid for an anti-skid device, which includes an electromagnetic valve having at least a position that allows the liquid to flow out, and an electric pump that returns the brake liquid in the reservoir to a line between the brake master cylinder and the electromagnetic valve. In the pressure adjusting device, between the location where the discharge liquid of the electric pump of the pipeline flows in and the brake master cylinder, a differential pressure response valve that allows a flow from the brake master cylinder side to the solenoid valve side, A throttle passage in parallel with the differential pressure response valve and a brake mass in parallel with the differential pressure response valve and from the solenoid valve side. It has a structure in which a check valve which permits flow to the cylinder side.

[0006]

In the invention of this application having the above structure,
If the hydraulic pressure on the solenoid valve side becomes higher than the hydraulic pressure on the brake master cylinder side due to the brake fluid being returned to the pipe line by the operation of the electric pump, the brake fluid on the solenoid valve side will pass through the check valve and the brake master. Since the fluid flows to the cylinder side, the brake fluid pressure in the wheel brake cylinder is not lowered and risen repeatedly, so that the reservoir is not filled with the brake fluid. Therefore, the brake fluid pressure in the wheel brake cylinder cannot be lowered. Disappears.

FIG. 1 shows an embodiment of the invention of this application. In FIG. 1, one of two pressure chambers inside a tandem type brake master cylinder 12 connected to a brake pedal 11 is provided with a pipe line 13. Valve device 14 and solenoid valve 1
Hydraulically connected to the wheel brake cylinder 16 via 5.

The solenoid valve 15 is a wheel brake cylinder 16
Normally open solenoid valve S that controls the flow of brake fluid into the
V1; a normally closed solenoid valve SV2 that controls the outflow of brake fluid from the wheel brake cylinder 16; and a check valve CV1 that is parallel to the solenoid valve SV1.

The brake fluid flowing out through the opening / closing solenoid valve SV2 is stored in the reservoir 17 and returned to the pipe line 13 between the opening / closing solenoid valve SV1 and the brake master cylinder 12 by the electric pump 18.

The valve device 14 is a brake master cylinder 1
Differential pressure response valve R that allows flow from the 2 side to the solenoid valve 15 side
V, a throttle passage CH in parallel with the differential pressure response valve RV, and a parallel relationship with the differential pressure response valve RV, and a check valve that allows a flow from the solenoid valve 15 side to the brake master cylinder 12. It is composed of a valve CV2. The throttle passage CH is preferably provided in the form of a slit on the valve seat surface of the differential pressure response valve RV.

When the driver steps on the brake pedal,
The brake master cylinder 12 sends the brake fluid to the wheel brake cylinder 16. The brake fluid flows into the wheel brake cylinder 16 through the differential pressure response valve RV and the throttle passage CH through the conduit 13, and further through the opening / closing solenoid valve SV1, and the brake fluid pressure in the wheel brake cylinder 16 rises to the wheels. The brake is applied.

When the wheels tend to lock, an electronic control unit (not shown) activates the solenoid on-off valve SV1 to stop the increase in brake fluid pressure, and if the wheel does not tend to lock, the solenoid on-off valve is further closed. The SV2 is operated in the open state so that the brake fluid in the wheel brake cylinder 16 flows out to the reservoir 17 to reduce the brake fluid pressure and reduce the braking force on the wheels. The brake fluid in the reservoir 17 is supplied to the conduit 1 between the valve device 14 and the solenoid valve 15 by the electric pump 18 when the electric pump 18 is operated.
Returned to 3. The brake fluid returned to the conduit 13 returns to the brake master cylinder 12 through the check valve CV2 and the throttle passage CH.

When the locking tendency of the wheels is eliminated, the electronic control unit returns the open / close solenoid valve SV2 to the closed state, and further returns the open / close solenoid valve SV1 to the open state. As a result, the brake fluid on the brake master cylinder 12 side flows into the wheel brake cylinder 16 through the throttle passage CH or the differential pressure response valve RV, and the brake fluid pressure in the wheel brake cylinder 16 rises. At that time, brake master cylinder 1
The flow of the brake fluid from the 2 side to the wheel brake cylinder 16 side is limited to the throttle passage C until the flow rate exceeds a predetermined value (determined by the valve opening differential pressure value of the differential pressure response valve and the sectional area of the throttle passage CH).
Since it is passed through H, it is restricted, and the rising gradient of the brake fluid pressure in the wheel brake cylinder is reduced.

Even if the brake fluid is repeatedly flown into and out of the wheel brake cylinder 16 by the operation of the solenoid valve 15, the check valve CV2 of the valve device 14 causes a large flow of brake fluid to be braked from the solenoid valve 15 side. Master cylinder 1
Since it can flow to the 2 side, the inside of the reservoir 17 is not filled with the brake fluid.

[0015]

As described above, according to the invention of this application, by repeatedly decreasing and increasing the brake fluid pressure in the wheel brake cylinder, the reservoir is filled with the brake fluid and the brake fluid pressure is reduced. It will never become impossible.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the invention of claim 1 of this application.

[Explanation of symbols]

 11 ... Brake pedal 12 ... Brake master cylinder 13 ... Pipe line 14 ... Valve device 15 ... Electromagnetic valve 16 ... Wheel brake cylinder 17 ... Reservoir 18 ... Electric pump SV1 , SV2 ... Open / close solenoid valves CV1, CV2 ... Check valve CH ... Throttle passage RV ... Differential pressure response valve

Claims (1)

[Claims] 1. An electromagnetic valve having at least a position for interrupting supply of brake fluid from a brake master cylinder to a wheel brake cylinder and a position for allowing outflow of brake fluid from a wheel brake cylinder to a reservoir, and the inside of the reservoir. In a hydraulic pressure adjusting device for an anti-skid device, which comprises an electric pump for returning the brake fluid to a pipeline between the brake master cylinder and the solenoid valve, a location where the discharge fluid of the electric pump flows into the pipeline. Between the brake master cylinder and the brake master cylinder, a differential pressure response valve that allows a flow from the brake master cylinder side to the solenoid valve side, a throttle passage in parallel relation to the differential pressure response valve, and the differential pressure response. A check valve provided in parallel with the valve and allowing a flow from the solenoid valve side to the brake master cylinder side is provided. Hydraulic pressure adjustment device for chiskid device.