Patent ID: 6024424
Filing Date: 2000-02-15
Classification: B60T,Y10S,Y10T

Abstract:
A braking device comprising:a fluid pressure source for generating a brake fluid pressure according to a driver's brake operation;a brake actuating part for applying a braking force to a wheel by the fluid pressure source generating fluid pressure and transmitting fluid pressure through a brake circuit;a fluid pressure control valve, arranged in the brake circuit, capable of decreasing, holding and increasing brake fluid pressure of the brake actuating part;a pump for returning brake fluid reserved in a reservoir arranged in a drain circuit in which brake fluid is drained when the fluid pressure of the fluid pressure control valve is decreased into an upstream part of the fluid pressure control valve of the brake circuit;a suction circuit for connecting a suction side of the pump with a brake fluid source;an IN-side gate valve for opening and closing the suction circuit;an OUT-side gate valve, arranged between a discharge position of the pump and the fluid pressure source in the brake circuit, for opening and closing the brake circuit;a relief circuit which comprises a relief valve bypassing the OUT-side gate valve, arranged in parallel with the brake circuit, for relieving fluid pressure on the fluid pressure control valve side of the OUT-side gate valve into the fluid pressure source side of the OUT-side gate valve; anda control unit for controlling the pump, the fluid pressure control valve, the IN-side gate valve and the OUT-side gate valve;wherein the control unit opens the IN-side gate valve, closes the OUT-side gate valve, generates brake fluid pressure by driving the pump regardless of the driver's brake operation, controls the fluid pressure of the brake actuating part by the fluid pressure control valve at a predetermined pressure and performs motion stabilizing control stabilizing a vehicle behavior when a predetermined vehicle behavior is detected;wherein the relief valve comprises a valve element for opening and closing the relief circuit by changing from a closing condition in which the valve element abuts on a valve seat to an opening condition in which the valve element is away from the valve seat;wherein the valve element comprises an opening pressure receiving part receiving fluid pressure on the fluid pressure control valve's side of the relief circuit in a direction of opening the valve and a closing pressure receiving part receiving pressure in a direction of closing the valve;wherein the relief valve further comprises a spring for urging the valve element in a direction of closing the valve; andwherein the closing pressure receiving part faces a closing valve chamber separated from the relief circuit in a fluid-tight condition.