Verfahren zur Steuerung eines stufenlos arbeitenden Getriebes

摘要

A method for controlling a continuously variable transmission (6) having a pair of pulleys each of which includes a groove defined between a stationary pulley element (8,14) and a movable pulley element (10,16), including the step of using hydraulic oil for increasing and decreasing the width of the groove to respectively decrease and increase the radius of rotation of a belt (4) looped around the pulleys to thereby vary the transmission ratio. A hydraulic clutch is provided (74), and connection and disconnection of the clutch is controlled according to various predetermined control modes. Line pressure is controlled with a control device (90) which uses both open loop control, and closed loop feedback control responsive to a signal from a pressure sensor. During open loop control, the line pressure is controlled so as to reflect the clutch pressure during a vehicle start mode.