HYDRAULIC PRESSURE CONTROL DEVICE

摘要

A hydraulic pressure control device including a valve for generating a circulating pressure to a hydraulic power transmission chamber in which power is transmitted between an input- and output side of a hydraulic power transmission element via hydraulic oil; and a valve for generating a lock-up pressure supplied to a lock-up chamber that faces the hydraulic power transmission chamber with a lock-up piston included in a lock-up clutch interposed therebetween. The hydraulic pressure control device controls the hydraulic pressures in the hydraulic power transmission chamber and in the lock-up chamber; and the circulating pressure valve has a spool to which the circulating pressure is applied as a feedback pressure and another hydraulic pressure is applied when the lock-up clutch is engaged/disengaged, and a spring urges the spool, and sets the circulating pressure to a constant first pressure when the lock-up clutch is disengaged and to a constant second different pressure when the lock-up clutch is engaged, depending on forces to the spool by the feedback pressure and on the spring.