| 摘要 |
PURPOSE:To facilitate setting of servo ratio by arranging a reaction piston formed with an effective cross-section onto which boost liquid pressure is applied slidably in a power piston. CONSTITUTION:A power piston 5 slides in a double pressure chamber 20a then responds to boost liquid pressure to drive a master cylinder 10 through an output rod 4. A reaction piston 22 formed with an effective cross-section onto which boost liquid pressure is applied is provided in the power piston 5. One end of the reaction piston 22 is coupled with an input rod 3 while the other end faces with an output rod 4 and arranged slidably against the power piston 5 through a reaction disc 4a made of elastic member. Since reaction of boost liquid pressure is obtained through the reaction piston 22, servo ratio can be set easily by setting an easily modifiable portion in the cross-section of respective parts, e. g. small diameter portion of the reaction piston 22, to a desired value. |
