| 摘要 |
<p>A master cylinder device (110) comprises a main body section (650) wherein a first pressure chamber (R1) which is for pressurising an operating fluid is partitioned off, and a flange section (652) which is on the outer periphery of the main body section; the device is provided with a first pressure piston (604) wherein a facing chamber (R4) filled with operating fluid is partitioned off in front of the flange section, and an input piston (608) wherein a between-piston chamber (R6) is partitioned off at the front thereof by the first pressure piston, and which can be contracted by the operation of a brake pedal (150). The device is further provided with: an electromagnetic opening and closing valve (732) which permits the input piston to abut the pressure piston, and connects the facing chamber and the between-piston chamber to a reverser (122); and another electromagnetic opening and closing valve (742) which prevents the contraction of the input piston. By configuring the master cylinder device in this way, operational force can be depended upon and so the operational fluid in the pressure chamber can be pressurised with the contraction of the input piston prevented.</p> |
