Control device of a lock-up mechanism

摘要

A control device for a lock-up mechanism arranged parallel with a hydraulic type torque transmitting mechanism that transmits rotatory power of a pump impeller connected with an output shaft of an engine to a turbine impeller connected with a wheel side element. The lock-up mechanism controls a slip value between the rotational speeds of the pump and turbine impellers in response to supplied hydraulic pressure. The control device calculates a target slip value, detects an actual slip value based on the rotational speed difference of the pump and turbine impellers, sets an intermediate slip value between the actual and target slip values, controls the hydraulic pressure to the lock-up mechanism so that the actual and intermediate slip values coincide, and reduces the intermediate slip value to a renewed value closer to the target slip value than the intermediate slip value when the actual slip value reaches the intermediate slip value.