SHIFT CONTROL SYSTEM OF HYDRAULIC CONTINUOUSLY VARIABLE TRANSMISSION FOR VEHICLE

A shift control system of a hydraulic CVT for an automotive vehicle with which it is possible to control a speed ratio to a target value with certainty while maintaining a required primary pressure, even when the vehicle is substantially stationary. Normally, a speed feedback control means sets a target speed of a rotating element on the basis of the vehicle speed and the load on the vehicle engine. The speed feedback control means feedback-controls a hydraulic pressure control means of the rotating element so that the actual speed approaches the target speed. When the vehicle becomes substantially stationary, control of the hydraulic pressure control means is switched from the speed feedback control executed by the speed feedback control means to pressure feedback control executed by a pressure feedback control means. That is, the actual hydraulic pressure acting on the rotating element is detected by a hydraulic pressure detecting means. A target hydraulic pressure setting means sets a target hydraulic pressure to act on the rotating element, and the shift control valve is feedback-controlled so that the actual pressure approaches the target pressure.