Brake servo unit control device

摘要

The invention relates to a brake servo having a boost function a pressure sensor (103) for detecting the pressure of the master cylinder (102), a current source (104) for supplying the solenoid (50), a pressure-increase control function. The solenoid current increases at low temperatures and decreases at high temperatures because the modulus of elasticity (100) of an elastically deformable valve body and the slide resistance of an elastically deformable seal member vary with temperatures (70). To supply the solenoid current necessary for opening (150) the valve mechanism without directly measuring the temperature, the solenoid current indicated when the pressure varies with the opening of the valve mechanism (100) is recorded at the time of pressure increasing, and thereafter when the valve mechanism is opened again after the closing, the solenoid current computed on the basis of the pressure-increase starting current learning value thus recorded is supplied. <IMAGE>