Brake system for electric motor-powered vehicle

摘要

Improving operating feelings and energy saving are aimed for a brake system of the type in which a predetermined differential pressure is produced between a master cylinder and wheel cylinders by a hydraulic pressure limit/changeover means during regenerative braking, and at the end of regenerative braking, the differential pressure is cancelled by increasing the pressure in the wheel cylinders with fluid sucked up from a reservoir for pressure increase by an electric pump. A reservoir for pressure increase, which is also used as a stroke simulator, is provided on the master cylinder side of the hydraulic pressure limit/changeover means, an on-off valve and a check valve are provided parallel to each other on the inlet side of the reservoir for pressure increase, so that the split point hydraulic pressure and the pressure-reducing ratio of a proportional pressure-reducing valve for supplying brake fluid toward the wheel cylinders during the initial period of braking can be brought unlimitedly close to zero.