| 摘要 |
PROBLEM TO BE SOLVED: To provide a master cylinder, preventing a piston seal from being damaged.SOLUTION: The piston seal 45 includes: a ring-like base part 90; an inner peripheral lip part 91 projected from an inner peripheral side of the base part 90 to be in slide-contact with an outer peripheral face of a piston; an outer peripheral lip part 92 projected from an outer peripheral side of the base part 90 to be in contact with a circumferential groove of a cylinder body; and an intermediate projection part 93 projected more than the outer peripheral lip part 92 from between the inner peripheral lip part 91 and the other peripheral lip part 92 of the base part 90. A plurality of projections 96 are circumferentially arranged on a tip side of the intermediate projection part 93, and the projection 96 is formed so that the rigidity of one side in the circumferential direction is different from that of the other side. |
