Control system for torque converter

摘要

A control system for a torque converter includes a lockup clutch provided in the converter for connecting input and output shafts of the torque converter directly. The lockup clutch includes an engaging chamber and a releasing chamber. The control system further includes a lockup shift valve for selectively switching communication between a fluid line, having a predetermined pressure, and the engaging chamber and communication between the fluid line and the releasing chamber. A lockup control valve is provided for controlling a pressure difference between fluid pressures in the engaging chamber and the releasing chamber and a control valve is provided for controlling the lockup clutch so that it engages completely. A first on-off solenoid valve controls the lockup shift valve, a duty solenoid valve controls the lockup control valve, and a second on-off solenoid valve controls the control valve.