Vorrichtung zur Steuerung der Überbrückungskupplung eines Drehmomentwandlers in einem automatischen Kraftfahrzeuggetriebe

摘要

A spool of a lock-up control valve has a first effective area exposed to a release pressure which is supplied to a release chamber of the lock-up clutch and a second larger effective area which is exposed to the apply pressure which is supplied to an apply chamber. When acceleration is demanded when the lock-up clutch is in one of slip or fully lock-up modes and a sudden demand for acceleration is made, the pressure differential between the apply and release pressures is reduced below the normal level for a predetermined period of time.