| 摘要 |
PROBLEM TO BE SOLVED: To provide a brake hydraulic pressure source provided with an auxiliary hydraulic pressure chamber controlling the auxiliary hydraulic pressure during braking operation, and multiplying a brake operation force at a prescribed constant servo rate. SOLUTION: A booster output corresponding to a brake operation force, and an auxiliary pressing pressure corresponding to a hydraulic pressure of an auxiliary hydraulic pressure chamber 50 are applied on a pressing piston 32, the combined force forwards the pressing piston 32, and a hydraulic pressure corresponding to the combined force is generated in pressing chambers 36, 38. While the booster output is constant, when the auxiliary hydraulic pressure increases, servo rate increases, and when the auxiliary hydraulic pressure decreases, the servo rate decreases. Controlling the auxiliary hydraulic pressure maintains the servo rate close to a constant value. |
