Patent ID: 6039675
Filing Date: 2000-03-21
Classification: F16H,Y10T

Abstract:
A slip control system for a torque converter with a lockup clutch, the slip control system controlling a slip rotation speed between a pump impeller and a turbine runner of the torque converter at a target slip rotation speed by controlling an engagement pressure of the lockup clutch, the pump impeller being connected to an engine to receive an engine output torque, the slip control system comprising:a vehicle condition detector that detects an operation condition of a vehicle equipped with the torque converter and the engine;an engine output torque determining section that determines the engine output torque on the basis of signals output from said vehicle condition detector;a turbine runner rotation speed detector that detects a rotation speed of the turbine runner;a reference value calculating section that calculates a reference value of the lockup clutch engagement pressure on the basis of the engine output torque as determined by the engine output torque determining section, the target slip rotation speed, and the rotation speed of the turbine runner as detected by the turbine runner rotation speed detector;a slip rotation speed difference lockup clutch engagement pressure calculating section that calculates a slip rotation speed difference lockup clutch engagement pressure which is a change amount of the lockup clutch engagement pressure to adjust an actual slip rotation speed to the target slip rotation speed; anda lockup clutch engagement pressure command value calculating section that obtains the sum of the lockup clutch engagement pressure reference value and the slip rotation speed difference lockup clutch engagement pressure as a lockup clutch engagement pressure command value and that outputs a signal indicative of the lockup clutch engagement pressure command value.