| 摘要 |
A plate plunger 17 that determines a servo ratio SR of a vacuum booster 1 pertaining to the present invention has, on a corner portion between its outer peripheral surface and its surface that opposes a reaction disc 16, a servo ratio determination surface 17c that is formed by an inclined surface and determines the servo ratio. The servo ratio determination surface 17c comprises a reaction disc contact surface 17f that determines the servo ratio and a reaction disc non-contact surface 17g. Additionally, a variety of different servo ratios are obtained by performing secondary processing such as cutting or grinding on just the servo ratio determination surface 17c to change the outer peripheral diameter of the reaction disc contact surface 17f. |
