JPS6159939B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a brake fluid pressure control valve device for an automobile.

In automobile braking systems, in order to prevent the rear wheels from locking up during braking, a hydraulic control valve device is installed in the brake fluid pressure circuit that runs from the master cylinder to the rear brake wheel cylinder, and the hydraulic pressure is supplied to the rear brakes. A measure is generally used to suppress the maximum brake fluid pressure supplied to an appropriate value (see, for example, Japanese Patent Laid-Open No. 58280/1983).

However, by installing a hydraulic pressure control valve in the rear wheel brake hydraulic circuit as described above, it is possible to improve braking stability when driving straight, but when braking when turning, the load on the inner wheel of the rear wheel is greater than the load on the outer wheel. As this decreases, a problem called inner ring front lock occurs.

The purpose of the present invention is to address the above-mentioned conventional problems.The present invention performs the conventional function when braking when driving straight, but transfers the braking force from the outer wheels to the inner wheels when braking when turning. In contrast, the present invention provides a brake fluid pressure control valve device which is made larger and can prevent the tip from locking on the inner wheel side.

The present invention will be explained below with reference to the accompanying drawings.

In Fig. 1, 1 is a brake pedal, 2 is a master cylinder, 3 and 3' are front wheel brake devices,
4 and 4' indicate rear wheel side brake devices, from the master cylinder 2 to the rear wheel side left and right brake devices 4,
Hydraulic pressure control valve devices 7, 7' are interposed in brake hydraulic pressure piping 6, 6' leading to each wheel cylinder 5, 5', respectively.

As shown in FIG. 3, the hydraulic control valve devices 7 and 7' have balls 72 and 72' loosely fitted inside cylindrical bodies 71 and 71' so as to be able to roll in the front and rear directions. Outlet ports 73, 73' are provided on the front end surfaces of the main bodies 71, 71', and the brake fluid enters the main bodies 71, 71' from the braking initial master cylinder 2 through the inlet ports 75, 75'. Fluid pressure is at outlet port 7
3, 73' to the wheel cylinders 5, 5', but when the deceleration due to braking reaches the set value, the balls 72, 72' move forward due to inertia and hit the valve seats 74, 74', causing the ball to go out. It has a structure that functions similar to what is generally called a G valve, which closes the let ports 73, 73' and suppresses any further rise in brake fluid pressure.

In the present invention, as described above, the valve device 7 controls the maximum hydraulic pressure supplied by the inertia of deceleration due to braking,
The main bodies 71, 71' of 7' are constructed as shown in FIG.

The inner cavities 76, 76' of the main bodies 71, 71' are generally formed to have a circular cross section, and when the balls 72, 72' roll forward due to inertia, the outlet ports 73, 73' provided at the center of the end face are opened. ball 72,7
Normally, the lumen 76 has a circular cross section, but in the present invention, the lumen 76 has a circular cross section.
76' is expanded to the left in the left valve body 71 and to the right in the right valve body 71' to form lumen bulges 77, 77', and the lumen 7
Projecting step portions 78, 78' are formed at the bottom of the boundaries from 6, 76' to the inner cavity bulges 77, 77', respectively.

Then, from the protruding steps 78, 78', the lumen bulge 7
The distance a to the side wall surface of balls 72 and 77' is
72' is configured to have a radius smaller than d/2.

In the above configuration, when braking while traveling straight, the balls 72 and 72' are both guided by the protruding step portions 78 and 78', and due to the inertia caused by the initial braking, the balls 72 and 72'
Valve seat 7 of outlet port 73, 73' moved forward inside 76' and provided in the center thereof.
4 and 74', and is closed to prevent further increase in rear wheel braking force and prevent the problem of rear wheel front lock.

The operating characteristics in this straight-ahead state are exactly the same as the conventional G valve.

During braking when the vehicle is turning, the ball receives lateral acceleration caused by the turning, and the ball tends to move outward with respect to the center of the turn.

For example, when turning left, the ball 72 in the left valve body 71 tries to move to the right, but the inner cavity 76
However, the ball 72' of the right valve body 71' runs onto the protruding step 78' due to the lateral acceleration as shown by the chain line, and the ball 72' of the inner lumen bulge 77' is restrained from lateral movement. Move until it hits the side wall.

When braking is performed in this state, both balls 72, 72' move forward due to the deceleration at the initial stage of braking, and the ball 72 on the left side closes the outlet port 73, but the ball center of the ball 72' on the right side moves forward. Since it is shifted to the right side of the outlet port 73', the port 73' cannot be closed even if it moves forward, and the braking force of the right brake is not controlled by the valve 7' but is generated by the master cylinder. As the brake fluid pressure increases, the braking force also increases.

Therefore, during a left turn, the braking force of the right wheel, which is the outer wheel, is greater than the braking force of the left wheel, which is the front wheel, and the problem of inner wheel front locking is completely eliminated.

When braking when turning right, completely opposite to the above,
The ball 72' on the right side controls the brake fluid pressure, but the ball 72 on the left side moves to the left as shown by the chain line and does not control the brake fluid pressure, so that the problem of the inner wheel first locking is eliminated as described above.

When returning from the turning state to the straight-ahead state, the ball pressed against the side wall surface of the lumen bulge will naturally move into the lumen due to its own weight since its center is located closer to the lumen than the protruding step. Return to the specified position.

As described above, the present invention uses an extremely simple configuration to ensure the function of preventing rear wheel front lock during braking in a straight-ahead running state, and also to accurately prevent the problem of inner wheel front lock during braking in a turning state. Therefore, it is possible to obtain a brake fluid pressure control valve device that prevents the above-mentioned problems from occurring, which can bring extremely great practical effects.

[Brief explanation of the drawing]

The attached drawings show an embodiment of the present invention. Fig. 1 is an explanatory diagram of the brake hydraulic piping system, Fig. 2 is a sectional view of the left and right hydraulic pressure control valves, and Fig. 3 is a cross-sectional view taken along line X-X in Fig. 2.
Or it is a sectional view taken along the YY line. 1... Brake pedal, 2... Master cylinder, 4, 4'... Rear wheel brake device, 5, 5'...
...Rear brake wheel cylinder, 6,6'...
...Brake hydraulic piping on the rear wheel brake side, 7, 7'...
...hydraulic pressure control valve device, 71, 71'...main body,
72, 72'...ball, 73,73'...outlet port, 75,75'...inlet port, 76,76'...lumen part, 77,77'...lumen bulge part, 78, 78'...Protruding step portion.

Claims (1)

[Scope of Claims] 1. In the brake fluid pressure supply system that supplies brake fluid pressure from the master cylinder to each wheel cylinder of the left and right rear wheel brakes, there are left and right fluids that suppress the maximum fluid pressure supplied to the brake fluid pressure to a predetermined value. In the device equipped with a pressure control valve device, the left and right hydraulic pressure control valve devices have balls loosely mounted in the inner cavity of the main body, and the balls move forward as the vehicle decelerates, The outlet port provided at the center of the front face of the brake valve is closed to stop further brake fluid pressure supply, and the inner cavity is located on the left side for the left control valve device and on the left side for the right control valve device. 1. A brake fluid pressure control valve device for an automobile, characterized in that the brake fluid pressure control valve device is configured to expand to the right side to form a lumen bulge, and to move a ball toward the lumen bulge due to lateral acceleration. 2. A protruding step that protrudes upward is formed at the bottom of the boundary between the lumen and the lumen bulge, and the distance from the protruding step to the side wall surface of the lumen bulge is equal to that of the ball. The brake fluid pressure control valve device for an automobile according to claim 1, wherein the brake fluid pressure control valve device for an automobile is configured to be smaller than the radius.