| 摘要 |
PURPOSE:To reduce the dimension of a hydraulic boosting device in the axial direction by reducing the loss stroke in the beginning of the operation of an input shaft, and arranging a reacting piston and a stopper in an overlapped manner in the axial direction. CONSTITUTION:A reacting piston 55 is kept oiltight, and inserted and fitted to a housing (plug) 5 in a slidable manner. One end of the reacting piston is provided facing a power chamber 8, and the other end facing a discharging passage 38 on the low pressure side. The reacting piston 55 recedes against the elastic force of a spring 57 when the hydraulic pressure is introduced into the power chamber 8, and the boosting ratio is changed by bringing the piston into contact with a stopper 17A provided to the input shaft 17. A slit 55B is formed on the power chamber side of the reacting piston 55, and a stopper 61B provided to the input shaft 17 is penetrated through the slit. The stopper 61B is brought into contact with the plug 5 in the non-actuated condition, and locates the input shaft 17 in the advancing position relative to the power piston. |
