| 摘要 |
PROBLEM TO BE SOLVED: To improve seat quality of a dump valve and processing quality of the valve body and valve seat of the dump valve. SOLUTION: The emergency accumulator 73 of a hydraulic booster 1 is provided with a dump valve 184 which supplies accumulated pressure to a power pressure chamber 32 by conducting releasing by means of braking operation in the case of emergency. The dump valve 184 is provided with a tapered seat part and a ball 188 which is seated on the seat part, and a pin 189 which pushes up the ball 188 and releases it. The pin 189 is supported in a hole formed at a guide member 190 so as to be capable of sliding, and is guided by the guide member 190 to move back and forth. A rod 189 is separated from the ball 188, and the pin 189 is guided by the guide member 190 to move back and forth, thus it is possible for the ball 190 to be seated on the seat part completely without the pin 189 being inclined. |
