GEAR-SHIFT TORQUE DOWN CONTROL DEVICE OF AUTOMATIC TRANSMISSION

A system for controlling a torque reduction at shifting for an automatic transmission is provided with actual gear-ratio detecting means for detecting an actual gear ratio out of input rotation and output rotation of the automatic transmission, and torque-reduction amount computing means for calculating a torque-reduction amount out of a torque-reduction set gain set previously, which is a rate of change of the torque-reduction amount with respect to a change in gear ratio, and the detected actual gear ratio. With this, the start and completion timings of torque-reduction control can be optimized to prevent elongation of shifting. This results in enhancement in the shift quality and in the endurance reliability of a friction material for shifting.