Patent ID: 7942483

Claim:
A brake system comprising: a master cylinder that generates a brake fluid pressure upon a driver's braking operation; a wheel cylinder for braking a wheel; a fluid passage that connects the master cylinder to the wheel cylinder; a braking force generating device that electrically generates a braking force for braking the wheel in response to the driver's braking operation; and a depressing force cut-off valve provided in the fluid passage that is closed by energizing a solenoid during normal operation of the braking force generating device, and opened by de-energizing the solenoid when an abnormality occurs, said depressing force cut-off valve operable to isolate the master cylinder from the wheel cylinder when said solenoid is energized; wherein the system is configured so that when brake fluid pressure is applied to the depressing force cut-off valve by the master cylinder, the depressing force cut-off valve is operable as a one-way valve that is urged in a valve-closing direction by the brake fluid pressure from the master cylinder.