Patent ID: 6789857
Filing Date: 2004-09-14
Classification: B60T

Abstract:
A vehicle brake hydraulic pressure generating device provided with a pressure adjusting device including a master cylinder, said vehicle brake hydraulic pressure generating device comprising a hydraulic pressure source for generating a predetermined hydraulic pressure, an atmospheric reservoir, a stroke simulator, said stroke simulator comprising a simulator piston operatively coupled with a brake operating member and an elastic member for imparting a stroke corresponding to the brake operating force to said simulator piston and a simulator chamber formed in front of said simulator piston, an input piston having said simulator piston therein for receiving the brake operating force from said simulator piston through said elastic member, and a pressure adjusting valve which activates according to the displacement of said input piston or said simulator piston to adjust the hydraulic pressure supplied from said hydraulic pressure source to a value corresponding to the brake operating force, a master cylinder having a master piston and activated by the fluid pressure from said pressure adjusting valve, and an auxiliary piston provided between said input piston and said master piston with its front protruding into a fluid chamber for applying the output fluid pressure from said pressure adjusting valve to said master piston of said master cylinder, said auxiliary piston being pushed by said input piston upon failure of a hydraulic line connecting to said fluid chamber and transmitting the brake operating force to said master piston,characterized in that a shutoff valve which shuts off the communication between said simulator chamber and said atmospheric reservoir when the stroke of said input piston relative to a housing for said input piston exceeds a predetermined value and a check valve which permits the flow of brake fluid from said atmospheric reservoir to said simulator chamber are provided.