| 摘要 |
PROBLEM TO BE SOLVED: To simplify a system and to further improve the responsiveness of a hydraulic booster. SOLUTION: With brake operation, the operation of a pump 40 is started, and at the same time an input shaft 22 and a valve spool 26 move forward. Communication between an annular groove 26e and a radial hole 17d is thereby cut off, and a conical valve 73a is separated from a valve seat 17d to open a first hydraulic pressure supply valve. Pump pressure and accumulator pressure are thereby introduced into a power chamber 13 through the open first hydraulic pressure supply valve. Then a power piston 12 moves forward, and a hydraulic booster 2 is actuated to be output. When pump delivery pressure reaches a prescribed pressure, supply of accumulator pressure is stopped by an accumulator pressure supply passage cutoff valve 42. In addition, a diameter contracted part 32 is positioned in front of a sealing member 29 by the forward movement of the valve spool 26, and a second hydraulic pressure supply valve is opened. Pump pressure and accumulator pressure the introduced into the power chamber 13 through the second hydraulic pressure supply valve.
|
