| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent a stopper pin from coming off with a simple mechanism, and to miniaturize a master cylinder by providing a groove part on a circumferential surface of an end part of the stopper pin to support a tip of a valve stem and to regulate the backward limit of a center valve. SOLUTION: In a tandem hydraulic master cylinder, a primary piston 4 and a secondary piston are fitted in a cylinder bore 3 of a cylinder body 2, and a return spring 15 is contracted between both pistons. A longitudinal communication hole 4f and a transverse communication hole 4g are formed in the primary piston 4 in an intersecting manner, a valve stem 17 of a center valve 16 is inserted in the longitudinal communication hole 4f, and a stopper pin 18 to be fitted to an insertion hole of a stopper ring 8 is attached to the transverse communication hole 4g. A groove is formed in both end parts of the stopper pin 18, and the stopper pin 18 is prevented from coming off by engaging an end turn part of a coil spring 7 to be fitted to the stopper ring 8 with each groove.</p> |
