| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a vehicular hydraulic master cylinder can gradually increase hydraulic pressure and obtain an excellent operation feeling during operation with a simple structure. <P>SOLUTION: A cup seal 12 is suitable for a cylinder hole bottom part side surface of a large diameter flange part 10b formed in a piston 10. A recess part 10c for elastically deforming the outer peripheral side of a base part 12c and the base end side of an outer peripheral lip part 12a to the cylinder hole opening part side when preset predetermined hydraulic pressure is generated in a hydraulic chamber 13, is formed on the cylinder hole bottom part side surface outer peripheral side of the large diameter flange part 10b. <P>COPYRIGHT: (C)2010,JPO&INPIT |
