| 摘要 |
<p>A fluid operated booster comprising a first valve (4) for controlling the communication between an accumulator and a hydraulic pressure chamber (11), and a second valve (16,17) for controlling the communication between the hydraulic pressure chamber (11) and a reservoir, in which, a brake pedal rod (2) is operated to close the second valve (16,17) and to open the first valve (4), so that a hydraulic pressure is applied from the accumulator to the hydraulic pressure chamber (11) to act on a power piston (9), to cause the power piston (9) to provide an operating force, which is transmitted to a master cylinder (8) piston to provide a boosted hydraulic pressure for a brake system; in which, according to the invention, the first valve (4) is a spool valve which is mounted on the brake pedal rod (2) with a predetermined frictional force in such a manner that the spool valve (4) is movable a predetermined distance, and the first valve (4) is closed when the brake system is not in operation, so that no hydraulic pressure from the accumulator is applied to the sliding portion of the brake pedal rod (2). <IMAGE></p> |
