| 摘要 |
PROBLEM TO BE SOLVED: To provide a hydraulic brake device having a closed chamber formed between a master piston and a power piston, capable of communicating the closed chamber with a reservoir during non-operation of the brake and surely forming the closed chamber at the start of brake operation. SOLUTION: The power piston 21 is disposed in the rear of the master piston 12 through the closed chamber R3, and output power liquid pressure of an auxiliary liquid pressure source 40 is supplied to a power chamber R6 formed in the rear of the piston 21 through a pressure regulating means. The closed chamber R3 and the power chamber R6 are connected to each other through a normally opened opening and closing valve (e.g. a differential pressure responding check valve 30) closing in response to the start of brake operation, and during non-operation, the closed chamber is communicated with a reservoir 4 through the normally opened valve means, the power chamber and a pressure regulating means. |
