| 摘要 |
PURPOSE: To reduce the size of a whole and to reduce a manufacturing cost by providing structure such that a distribution valve device operated by an input member and a hub structure containing the distribution valve device are disposed in a booster housing. CONSTITUTION: A brake booster is provided with housings 10 and 12 partitioned into a vacuum chamber 14 and an actuating chamber 16 by a piston device comprising a plate 18; and a flexible diaphragm 20. In this case, a central part 22 forming a hub structure 24 to contain a distribution valve device 26 is arranged at the plate 18. The distribution valve device 26 has a valve plunger 28 coupled to an input member 56 driven by a brake pedal and an elastically pressed shutter element 36 seats a valve seat 32 concentric to a valve seat 34 formed at the rear end part of the valve plunger 28 and arranged at the central part 22. An input member 56 is energized in a direction in which this member is separated away from valve seats 32 and 34 by a return spring 60. |
