Patent ID: 6691012
Filing Date: 2004-02-10
Classification: F16H,Y10T

Abstract:
A shift control apparatus for a continuously variable transmission having a primary pulley provided with a primary cylinder and a secondary pulley provided with a secondary cylinder, whereby a continuously variable shifting is achieved by changing a wrap-contact diameter of a power transmission element relative to the primary pulley by supplying a primary pressure into the primary cylinder, comprising:a target primary pressure setting unit provided a target primary pressure according to a speed ratio deviation between an actual speed ratio between the primary pulley and the secondary pulley and a target speed ratio calculated according to running conditions of a vehicle; a shift control valve for regulating flow rate of hydraulic oil supplied to the primary cylinder by changing an opening area of the shift control valve according to current supplied to an electromagnetic coil; a primary pressure detecting unit for detecting the primary pressure supplied to the primary cylinder; and a control unit for controlling the speed ratio by correcting a basic current on the basis of the target primary pressure and supplied to the electromagnetic coil by feeding back the primary pressure.