System for controlling a continuously variable transmission having a torque converter.

摘要

A continuously variable belt drive transmission has a torque converter (3) with a lockup clutch (15). The transmission ratio of the transmission starts is changed, and the lockup clutch is engaged, in accordance with driving conditions of the vehicle. Thus, a start signal for starting of the changing of the transmission ratio is produced in accordance with driving conditions, and a lockup signal for engaging of the lockup clutch is produced in accordance with driving conditions by a control unit (80). In response to the start signal and to the lockup signal, the changing of the transmission ratio and engagement of the lockup clutch are performed at the same time by means of transmission ratio valve (45) and lockup control valve (63), respectively.