| 摘要 |
PROBLEM TO BE SOLVED: To stably provide a hydraulic characteristic of jumping the output of a secondary master cylinder in the initial stage of brake operation and then gently increasing the output hydraulic pressure of the secondary master cylinder in a brake hydraulic servo unit comprising a primary master cylinder for outputting a hydraulic pressure according to a brake operating input, a hydraulic pressure source, a proportional pressure intensifying valve for drawing and outputting the assisting hydraulic pressure according to the output hydraulic pressure of the primary master cylinder from the hydraulic pressure source, and the secondary master cylinder for operating a wheel brake with the brake hydraulic pressure according to the assisting hydraulic pressure outputted from the proportional pressure intensifying valve. SOLUTION: In this brake hydraulic servo unit, a proportional pressure reducing valve 8F for proportionally reducing the output hydraulic pressure of the proportional pressure intensifying valve 4F when the output hydraulic pressure of the valve 4F is a set pressure or more is provided between the proportional pressure intensifying valve 4F and the input hydraulic chamber 51 of the secondary master cylinder M2F. |
