Torque converter slip control device

摘要

A torque converter slip control device used in an automatic transmission of an internal combustion engine of a vehicle has a torque converter to transfer engine torque to an input shaft of the automatic transmission. A feed-forward slip control subroutine controls a hydraulic circuit in a feed-forward control to vary the coupling efficiency of a lockup clutch to cause the torque converter to allow slippage at a rate suitable for cancelling a fluctuation of engine torque when the internal combustion engine is at rotational speeds higher than a preselected rotational speed higher than a predetermined fuel injection recovery speed at which an injection of fuel by a fuel system is recovered during the detection of the deceleration state of the vehicle by a deceleration senser. A feed-back slip control subroutine controls the hydraulic circuit in feed-back control to vary the coupling efficiency of the lockup clutch to make a difference of rotational speed between input and output shafts of the torque converter suitable for cancelling a fluctuation of engine torque when the internal combustion engine is at rotational speeds lower than the preselected rotational speed during the detection of the deceleration state of the vehicle by the deceleration sensor.