CONTROL DEVICE FOR CONTINUOUSLY VARIABLE TRANSMISSION

摘要

PROBLEM TO BE SOLVED: To provide a control device for a continuously variable transmission in failure of a ratio control solenoid due to disconnection, etc., not only being free from causing an abrupt downshift and belt slip but also being capable of restarting. SOLUTION: This control device for the continuously variable transmission is provided with the ratio control solenoid 16 operated by an electric signal and controlling a shift control valve 17 provided in a hydraulic feed circuit 8 which feeds a pressure oil to a primary pulley 3, and changes the rotation radius of a belt 5 wound around between the primary pulley 3 and a secondary pulley 4 by controlling the shift control valve 17 so as to steplessly change the change gear ratio. A selector valve 18 capable of changing over the pressure oil to the primary pulley 3 to a discharge position is provided between the primary pulley 3 and the shift control valve 17, and a pressure retaining valve 20 is provided in the discharge position of the selector valve 18 in a discharge circuit 19 communicated with the primary pulley 3.