Patent ID: 6597979
Filing Date: 2003-07-22
Classification: F16H,Y10T

Abstract:
A lock-up control system for an automatic transmission including a torque converter having a power input element connected to an engine of a vehicle and a power output element connected to a power input shaft of the transmission, and a lock-up clutch housed in the torque converter and being capable of directly coupling the power input element and the power output element of the torque converter, said lock-up control system comprising:an accelerator pedal depression amount sensor for detecting a depression amount of an accelerator pedal; and a controller including: an accelerator pedal movement speed calculating section for calculating a movement speed of the accelerator pedal, a lock-up control section adapted to disengage the lock-up clutch in a condition in which a driving point of the vehicle is within a lock-up condition releasing region in a set lock-up schedule, and to engage the lock-up clutch in a condition in which the driving point is within a lock-up condition applying region, said lock-up control section including a first lock-up releasing control section adapted to gradually disengage the lock-up clutch from an engaging state and put the lock-up clutch into a disengaging state when the accelerator pedal movement speed is not lower than a set speed and an initial accelerator pedal depression amount in the accelerator pedal depression amount is not smaller than a set accelerator pedal depression amount to establish a driving condition of the vehicle under the engaging state of the lock-up clutch.