| 摘要 |
A lock-up control device is provided to control engaging force of a lock-up clutch, which shares engine output with a torque converter to transmit it toward an input shaft of a transmission. Herein, input shaft torque is estimated based on engine speed and engine intake negative pressure, while engine torque is estimated based on engine speed and throttle opening. A weight coefficient is produced based on an amount of variations of the engine torque when the amount of variations is greater than a prescribed value. Then, weighted mean engine torque is calculated by the input shaft torque and engine torque in accordance with the weight coefficient. Thus, the lock-up control device controls the lock-up clutch based on the weighted mean engine torque in such a way that the engaging force of the lock-up clutch is increased in response to the rise timing of the weighted mean engine torque. For example, the weight coefficient is determined in such a way that the engine torque is given high distributed weight in the weighted mean engine torque as compared with the input shaft torque. Thus, it is possible to increase the engaging force of the lock-up clutch promptly in response to the rise mode of the real engine torque, by which it is possible to avoid occurrence of control delay in control of the lock-up clutch. |
