| 摘要 |
PURPOSE:To alleviate shock upon shifting a vehicle into its lock-up mode, by coupling and discoupling a lock-up mode clutch to shift the vehicle into the lock- up mode. CONSTITUTION:Of various signals A through E introduced into a microcomputer 1, a vehicle speed signal A and a throttle opening signal B are used as parameters to control the shift positions of a speed change gear by means of a drive circuit 7 in such a way that first to third solenoid are operated to change over a hydraulic circuit. When various running conditions are judged to be suitable for such a condition that the highest shift stage may be sustained on running, a lock-up clutch is operated by changing over the hydraulic circuit in association with energization of a fourth solenoid to directly couple an input shaft with an output shaft. This lock-up clutch is discoupled and coupled to transiently and variably control the duty ratio of the clutch with respect to the holding time thereof successively from 0-100%, and the time constant thereof is regulated in accordance with an intake-air vacuum signal E. |
