| 摘要 |
PROBLEM TO BE SOLVED: To enlarge a play margin of an input rod in the assisting force limit region and avoid a sense of backlash feeling of a brake pedal owing to the play margin. SOLUTION: A brake booster is composed of a boosting chamber 23 connected with the negative pressure of engine, a pressure change chamber 15 connected with the atmospheric pressure and the negative pressure, a diaphragm 13 to partition them from each other, a piston 2 fixed to the diaphragm 13, a poppet valve 7 which divides the internal space into a first space A in communication with the boosting chamber 23, a second space B in communication with the atmopheric pressure and a third space C in communication with pressure change chamber 5 and performs changing-over of the passage, an input rod 4, a plunger 8 which is coupled with the input rod and opens the opening of the valve 7 interlocking with the movement (+x) generated by the braking operation of the input rod, and a key 9 which regulates the relative displacement of the plunger 8 relative to the piston 2. An initially conical leaf spring 10a/10b is interposed between the key 9 and the key supporting surface of the piston 2 or the undersurface of the plunger 8. |
