| 摘要 |
PURPOSE: To easily switch the boosting factor by composing a valve plunger of a second valve plunger provided with a recessed part on an input rod side and a first valve plunger having a seal valve for the atmospheric control which is interlocked to an outer circumferential end part of the recessed part of the second valve plunger through a movable member. CONSTITUTION: A control valve 20 in a brake booster is engaged with an inner circumferential part of a power piston 10 at the input side end part, and is provided with a first valve plunger 12 arranged on the tip of an input rod 11. Two movable members 31 are provided on an output rod 15 side of the valve plunger 12, and an energizing member 30 is interposed inside the movable members 31. A stepped part projecting outwardly in the radial direction on the output side is provided with a second valve plunger 13 with a recessed part opened on the input side on the tip of the movable members 31. The first valve plunger 12 is abutted on the recessed part of the second valve plunger 13 according to the moving speed of the input rod 11, and the boosting factor is switched. |
