OIL PRESSURE CONTROL APPARATUS FOR STARTING APPARATUS

摘要

Oil pressure control apparatus (1), which has multi-plate type lockup clutch (3) and is connected to torque converter (4) by three oil paths, is equipped with a torque converter circulation modulator valve (5), which switches between a non-depressurization state, wherein secondary pressure PSEC is output unchanged as circulation pressure PB to input port (4b), and a depressurization state, wherein an oil pressure obtained by adjusting the secondary pressure PSEC to a constant pressure based on the feedback pressure of circulation pressure PB and the energizing force of spring (5s) is output as circulation pressure PB to input port (4b). In this way, the circulation pressure PB in torque converter (4) can be held in a stable depressurization state so that the controllability can be improved when lockup clutch (3) is engaged.