| 摘要 |
PROBLEM TO BE SOLVED: To provide a master cylinder capable of suppressing rolling caused in a sealing member.SOLUTION: A sealing member 45 includes: a base portion 101 capable of abutting on a circumferential wall 89 of an opening side of a cylinder body 15 at a circumferential groove 32; an inner peripheral lip portion 102 extended from the base portion 101 toward a bottom side of the cylinder body 15 and coming into sliding contact with an outer circumference of a piston 18; an outer circumferential lip portion 103 extended from the base portion 101 toward the bottom side of the cylinder body 15 and abutting on a bottom 88 of the circumferential groove 32; a center lip portion 104 extended from the base portion 101 between the outer circumferential lip portion 103 and the inner peripheral lip portion 102 toward the bottom side of the cylinder body 15, with an end capable of abutting on a circumferential wall 90 of the bottom side of the cylinder body 15 in the circumferential groove 32; and an intermediate lip portion 105 extended from the base portion 101 between the center lip portion 104 and the inner peripheral lip portion 102 toward the bottom side of the cylinder body 15, with an extended length formed shorter than the center lip portion 104. |
