| 摘要 |
PROBLEM TO BE SOLVED: To provide a master cylinder of improved quality.SOLUTION: A through hole which an input member penetrates is formed at a primary piston. The through hole is provided with a closing seal and a communication path which extends in a radial direction of the primary piston on a side opposite to a pressure chamber relative to the closing seal, so as to communicate the through hole with an outer periphery of the primary piston. Between a slide support part 28 to which a seal member of a cylinder body 15 is provided and a slide support part 27 to which a piston seal that slides and contacts to the primary piston is provided, a large diameter groove 47 acting as a refill path which recesses toward outer diameter side than the former is formed to communicate with the communication path. At the large diameter groove 47, an intermediate slide support part 210 is formed at a position at which it is divided in an axial direction to form a plurality of division groove parts 211, 212, with each of them shorter than dimension in an axial direction of a secondary piston 19. |
