SPEED CHANGE CONTROLLER FOR CONTINUOUSLY VARIABLE TRANSMISSION WITH LOCKUP TORQUE CONVERTER

摘要

PURPOSE:To restrain a torque converter from slippage by setting a desired value of the rotational frequency of a primary pulley or the like according to a traveling condition to increasingly correct the desired value to the low speed stage side in the operation of the torque converter when lockup OFF is determined. CONSTITUTION:In a control unit 70 for controlling a hydraulic control system of a lockup clutch is provided a searching section 72 for searching the desired primary pulley rotationnal frequency from an actual speed change ratio, throttle opening and shift position. A desired rotational frequency is calculated 73 from the desired primary pulley rotational frequency and secondary pulley rotational frequency. Also, the speed ratio of the input to output side of a torque converter is calculated 78 from the rotational frequencies of an engine and primary pulley and lockup ON or OFF is judged by a lockup determining section 79 from the speed ratio or the like. In the operation of the torque converter in the lockup OFF, the desired primary pulley rotational frequency is increasingly controllably corrected uniformly to the low speed stage side by a correction amount calculating means 90.