Patent ID: 6070951
Filing Date: 2000-06-06
Classification: B60T,F04B

Abstract:
In a motor vehicle having a brake pedal, and at least one road wheel which is equipped with a hydraulically actuated brake cylinder,a hydraulic brake system comprising:fluid pressure generating means for generating a brake fluid pressure in accordance with an actuation of said brake pedal;a brake circuit for providing a fluid communication between said fluid pressure generating means and said brake cylinder;a fluid pressure control valve installed in said brake circuit for controlling the fluid pressure in said brake cylinder;a reservoir connected to a discharge circuit extending from said fluid pressure control valve;a pump including a cylinder member, a plunger movably disposed in said cylinder member to define a volume variable pressure chamber, and a seal member operatively disposed between said cylinder member and said plunger to hermetically insulating said pressure chamber;a first inlet circuit for conveying the brake fluid in said reservoir to said pressure chamber of said pump;a second inlet circuit for conveying the brake fluid in said fluid pressure generating means to said pressure chamber of said pump;an outlet circuit for conveying the brake fluid in said pressure chamber of said pump to said fluid pressure control valve;an outside gate valve for selectively opening and closing said brake circuit;an inside gate valve for selectively opening and closing said second inlet circuit; anda control unit for controlling said fluid pressure control valve, said pump and said outside and inside gate valves for carrying out an antilock brake control and a vehicle motion stabilizing control,wherein said cylinder remember of the pump is formed with a pressure chamber exposed opening through which said second inlet circuit is fluidly communicated with the pressure chamber of the pump, said pressure chamber exposed opening being exposed to said pressure chamber even when said plunger takes a deepest position in the cylinder member to minimize the size of said pressure chamber.