Hydraulic brake system for vehicle

摘要

In a hydraulic brake system for a vehicle, the brake fluid in a first wheel brake and the brake fluid in a second wheel brake which are hydraulically connected to a pressure generating chamber of a master cylinder are individually caused to flow into a low back pressure reservoir with the aid of an electromagnetic change-over valve and first and second electromagnetic cut-off valves; and with a pump driven by an electric motor, the brake fluid flowing in the low back pressure reservoir in the above-described manner is caused to flow through a first check valve and a first orifice to the first wheel brake, and through a second check valve and a second orifice to the second wheel brake. With the pump operated, the first and second electromagnetic cut-off valves are individually operated, so that the first and second wheel brakes are individually decreased or reincreased in hydraulic pressure. For traction control, electromagnetic change-over valves provided in bypass passages are operated. Thus, with the system, anti-lock control and traction control can be achieved, and, even when the valves added for traction control become out of order, brake fluid can be supplied to or drawn from the wheel brakes as required.