| 摘要 |
<p>PURPOSE:To make an operating stroke unvaried according to the operating speed of a brake operating member as well as to prevent the operating stroke from being enlarged even at the time of breakage in both first and second systems, by installing a second power piston which heightens hydraulic pressure in a second pressurized chamber in response to a second power pressure chamber, and interconnecting this second power pressure chamber to a first power pressure chamber. CONSTITUTION:In a housing 12, there is provided with a second power piston 90 which is operated by receiving hydraulic pressure of a second pressurized chamber 20 one side and also receiving fluid pressure of a second power pressure chamber 92 on the other, and heightens the hydraulic pressure of the second pressurized chamber 20 in response to the second power pressure chamber 92, then the second power pressure chamber 92 is interconnected to a first power pressure chamber 58. Therefore, the second power piston 90 is set in motion in almost synchronous with the actuation of a first power piston 52 based on operation of an operating member 40, feeding a first system 24 with a fluid inside the second pressurized chamber 20, and an operating stroke is not varied according to an operating speed of the operating member 40. And, even in case of breakage in the first system 24 and a second system 26, the operating stroke is not enlarged.</p> |
