SWITCHABLE ORIFICE CONTROL VALVE IN ABS SYSTEM

摘要

An anti-lock brake system having a switchable orifice control valve (22) disposed between the master brake cylinder (16) and the brake assembly. The switchable orifice control valve, having a valve body, a stationary member, a movable member and a solenoid coil actuated armature. The switchable orifice control valve (22) has a normally open state, a closed state and a third state during an anti-lock mode of operation. In the third state the brake fluid from the master brake cylinder to the brake assembly flows through a calibrated re-apply orifice (38) which controls the rate at which the pressure of the fluid being applied to the brake assembly is increased at a predetermined rate. The switchable orifice control valve is held in the third state by a pressure differential orifice between the input and output ports of the switchable orifice control valve.