| 摘要 |
<P>PROBLEM TO BE SOLVED: To suppress an abnormal increase in pressure which is produced in a master cylinder and in a boost chamber of a hydraulic booster, which is caused by pump-back of fluid when the hydraulic booster for assisting brake operation is used in combination with a return-flow type pressure adjustment unit, and which will cause reduction in the durability of the master cylinder and the hydraulic booster. <P>SOLUTION: The hydraulic booster 3 is adopted in a hydraulic brake device having the return-flow type pressure adjustment unit 30, and comprises an auxiliary hydraulic pressure source 7, a pressure adjustment device 8 which adjusts hydraulic pressure supplied therefrom to a value corresponding to the amount of operation to a brake actuation member 1 and provides the same to the boost chamber 3b, and a boost piston 3c which generates assist force with the provided hydraulic pressure in the boost chamber 3b and actuates a master piston 2a. The hydraulic booster 3 has a hydraulic passage 12 that bypasses the pressure adjustment device 8 and leads from the boost chamber 3b to the auxiliary hydraulic pressure source 7, and a check valve 13 that is disposed in the hydraulic passage and allows only hydraulic discharge from the boost chamber 3b to the auxiliary hydraulic pressure source 7. <P>COPYRIGHT: (C)2013,JPO&INPIT |
