Hydraulic pressure control for continuously variable transmission

摘要

A belt type continuously variable transmission (CVT) (10) for a vehicle varies the speed ratio in accordance with the hydraulic pressure that is regulated via a hydraulic pressure regulating unit (30). A sensor (27) detects a vehicle speed. A CVT controller (20) calculates a target hydraulic pressure that is supplied to the CVT (10) on the basis of a predetermined speed change schedule so that the speed ratio varies in the direction of up-shifting as the vehicle speed increases (S15). The CVT controller (20) also determines whether or not a specified condition holds (S16, S160), and controls the hydraulic pressure regulating unit according to a target start-up hydraulic pressure which is larger than a target hydraulic pressure for normal running (S11, S13), thereby preventing a speed change lag when the vehicle starts to move.