VEHICLE BRAKING SYSTEM AND VEHICLE BRAKING DEVICE

摘要

A vehicle braking system and a vehicle braking device capable of effectively utilizing a braking energy stored in an auxiliary pressure source for braking even if an electric system fails, the vehicle braking system comprising a proportional pressure control valve (80) regulating a braking energy stored in the auxiliary pressure source (30) to generate a wheel brake fluid pressure, a pipe (75) introducing a fluid pressure generated by the operation of a brake pedal (1), a switching valve (76) closing the pipe when energized and opening the pipe when the electric system fails, i.e., not energized, and an auxiliary control part (81) operating the proportional pressure control valve (80) by the fluid pressure, wherein a brake pressure required for the proportional pressure control valve (80) is regulated by utilizing a high pressure output stored in the auxiliary pressure source (30) even in non-energized condition so as to utilize the pressure for braking force, whereby, if a relief valve (116) and a return valve (117) are provided in place of the switching valve (76) to operate the proportional pressure control valve (80), the high pressure output of the auxiliary pressure source (30) can be utilized more effectively even in energized condition.