In a master cylinder, a piston seal provided in a circumferential groove includes an annular base section, an inner circumferential lip section protruding from an inner circumferential side of the base section to come into sliding contact with an outer circumferential surfaced of a piston, an outer circumferential lip section protruding from an outer circumferential side of the base section to abut the circumferential groove, and an intermediate protrusion section protruding from a portion between the inner circumferential lip section and the outer circumferential lip section of the base section to a position further forward than the outer circumferential lip section. At least one inner circumferential side groove extending in an axial direction and opened at a front end side of the intermediate protrusion section is formed in a surface of the inner circumferential lip section side of the intermediate protrusion section.
Master cylinder
2019-07-16
Patent
Electronic Resource
English