| 摘要 |
PROBLEM TO BE SOLVED: To provide a negative pressure booster having a simple structure and capable of promptly introducing a large quantity of atmospheric air into an operating chamber to make an input rod exercise high output, a booster limit, during emergent braking. SOLUTION: An input plunger 18 connecting with a reaction mechanism 24 is connected to an input rod 20, and a valve piston 33 having an atmospheric air introducing valve seat 31 at its back end is engaged with the outer periphery of the input plunger 18 so as to be movable between a retreat position R and a forward position F and is energized toward the retreat position R by a return spring 44. First and second permanent magnets 51, 52 are respectively annexed to a valve cylinder 10 and the valve piston 33, generate repulsion for energizing the valve piston 33 toward the retreat position R when the valve piston 33 does not cover a specified distance (s) at the time of its advancement toward the valve cylinder 10 and generate attraction for moving the valve piston 33 to the forward position F when the valve piston 33 advances, covering a distance exceeding the specified distance (s). |
