Patent ID: 6056370
Filing Date: 2000-05-02
Classification: B60T

Abstract:
A brake pressure controller for a vehicle having a brake pedal comprising:a master cylinder for generating a brake pressure through operation of the brake pedal;a wheel cylinder connected to said master cylinder by a main path to which the brake pressure generated in said master cylinder is transmitted;a pressure increasing valve provided in said main path;a relief reservoir linked to said wheel cylinder through a relief path;a pressure reducing valve provided on said relief path;a shut-off valve provided in said main path between said master cylinder and said pressure increasing valve;a hydraulic pump linked to said relief reservoir for returning brake fluid in said relief reservoir to a section in said main path between said pressure increasing valve and said shut-off valve, said hydraulic pump having a suction side and a discharge side;a suction valve provided in a suction path that links said master cylinder to a part of said relief path between the suction side of said hydraulic pump and said relief reservoir, said suction valve being positionable in one position for permitting communication between the suction side of the hydraulic pump and the master cylinder and being positionable in a second position for preventing communication between the suction side of the hydraulic pump and the master cylinder;a restricted passage provided between said shut-off valve and said pressure increasing valve;a control device for controlling the suction valve and the hydraulic pump so that when a determined value that is based on a state of the vehicle exceeds a first predetermined value, said suction valve is opened and said hydraulic pump is driven to draw brake fluid from said master cylinder and supply brake fluid to the wheel cylinder, and for controlling the shut off valve so that when said determined value based on the state of the vehicle exceeds a second predetermined value greater than said first predetermined value, said shut-off valve is closed and said hydraulic pump is driven to further supply the brake fluid in said master cylinder to said wheel cylinder;a bypass passage linking the master cylinder to the wheel cylinder; anda normally closed cut valve disposed in the bypass path.