| 摘要 |
PROBLEM TO BE SOLVED: To provide a compactly constructed negative pressure type booster. SOLUTION: This negative pressure type booster is provided with a housing, a movable wall parting a constant pressure chamber and a variable pressure chamber from each other, a power piston 10, an inputting member 12, and a control valve 19. The negative pressure booster is also provided with a movable vacuum valve seat 24, which is arranged in the power piston 10 and is engaged with a seal part, 19a so as to cut off connection between the constant pressure chamber and the variable pressure chamber and so as to energize the seal part 19a in the direction in which it is separated from the air valve seat 13a when the inputting member 12 is moved apart from the seal part 19a, and a plate spring 26, which serves as a movable vacuum valve seat operating mechanism shifting the movable vacuum valve seat 24 toward the seal part 19a when the inputting member 12 is moved apart, from the seal part 19a. |
