| 摘要 |
PURPOSE:To secure large hysteresis by buriedly providing the highly hard annular member of a reaction disc on which the end face of a valve plunger abuts, and also radially compressing the disc when the disc is axially compressed during the operation of a booster. CONSTITUTION:In a brake booster, a valve plunger 2 connected with an input shaft is fittedly inserted in a stepped hole 1A drilledly provided in a valve body 1, and a concave sunk part 3a formed on the basic part of an output shaft 3 is fitted in the cylindrical part 1b of the stepped hole 1A of the valve body 1. A rubber reaction disc 4 is accommodated in the concave sunk part 3a, and the tip of the cylindrical part 1b of the valve body 1 abuts on the peripheral side of the right end face 4a of the disc 4. In this case, the right end face 4a of the disc 4 is buriedly provided with an annular member 5 being harder than the disc 4, and the periphery of the annular member 5 is partially exposed. The annular projection 1c of the valve body 1 is engaged with the exposed periphery to check the radial displacement of the annular member 5. |
