| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent the damage to a peripheral portion of a piston, and to prevent the entry of air into a brake fluid supplying chamber at the time of piston movement. SOLUTION: In an opening side of a cylinder 3, a sleeve 9 extending coaxially with respect to the cylinder and liquid-tightly communicating to the inside of the cylinder is provided. A seal material 16 sliding integrally with a primary piston 8 is interposed between the sleeve 9 and the primary piston 8. The sleeve 9 is provided with a stopper portion 30a abutting on a key plate 30 engaged with a primary center valve 22 and fixing a stop position of the center valve to an opening portion side of the cylinder.</p> |
