| 摘要 |
PURPOSE:To keep a speed change shock from becoming serious by setting the internal pressure of a torque converter lower during ordinary operation, temporarily increasing the internal pressure of the torque converter during speed change operation and letting operation pressure escape to an oil tank. CONSTITUTION:A torque converter T is provided with a clutch Cd for mechanically direct-coupling input and output members of the torque converter T with engagement capacity determined by a function of differential pressure between operation pressure working on the engagement side and internal pressure of the torque converter T working on the disengagement side. A switch valve 50 for letting operation pressure escape to an oil tank in synchronization with speed change operation and switch means 55 for switching the increase the internal pressure of the torque converter T in synchronization with speed change operation are connected to the direct-coupled clutch Cd. In this arrangement, the engagement of input and output members can be released quickly by the direct- coupled clutch Cd, so that at the time of speed change operation, the lock-up state can be released quickly so as to keep speed change shock from becoming serious. |
