Patent ID: 6126248
Filing Date: 2000-10-03
Classification: B60T

Abstract:
A hydraulic brake device comprising:a master cylinder for generating a master cylinder pressure in response to a brake pedal pressure;a high pressure source for generating an accumulator pressure higher than the master cylinder pressure;an electrical system for electrically controlling a brake fluid pressure supplied to a wheel cylinder based on the accumulator pressure supplied from the high pressure source into the wheel cylinder;a pressurizing chamber connected to the master cylinder for receiving the master cylinder pressure generated by the master cylinder;a pressure adjusting chamber connected to the high pressure source for receiving the accumulator pressure generated by the high pressure source;a booster piston movably provided between the pressurizing chamber and the pressure adjusting chamber, the booster piston being actuated in a first direction away from the pressurizing chamber by a pressure in the pressurizing chamber, and the booster piston being actuated in a direction opposite to the first direction by a pressure in the pressure adjusting chamber; anda flow control mechanism responsive to a movement of the booster piston for making the pressure adjusting chamber open to the high pressure source when the booster piston is moved in the first direction exceeding a predetermined distance, and for closing the pressure adjusting chamber to be cut off from the high pressure source when the booster piston is moved in the opposite direction back to an initial position,wherein the hydraulic brake device allows a boosted pressure in the pressure adjusting chamber to be produced based on the accumulator pressure when a malfunction in the electrical system is detected, and supplies the boosted pressure from the pressure adjusting chamber into the wheel cylinder.