摘要 |
An electronically controlled brake device for controlling a brake pressure according to a manual input (1). While the dynamic pressure line is functioning normally, the dynamic pressure acts on one end of a push rod (8) associated with a brake pedal (1) to give such a force as to counteract the control input to the brake pedal (1). If the dynamic pressure line fails, the push rod (8) comes into contact with a dynamic pressure piston (9) to transmit the control input force to a master cylinder (10). An electronic pressure control valve (4) is provided to adjust the connection of the dynamic pressure source (5) with a reservoir (4) and with a dynamic pressure chamber (7) in response to the commands of an electronic control unit (3) so that its output pressure will be in a predetermined relationship with the pedal stroke. Thus in normal conditions, a desired deceleration is obtained with a shorter pedal stroke and in the failure of dynamic pressure, a minimum deceleration is obtained with a lighter pedal force. |