Method of controlling continuously variable transmission

摘要

A static hydraulic continuously variable transmission includes a fixed capacity swash type hydraulic pump and a variable capacity swash type hydraulic motor, connected by a hydraulic closed circuit. A control system and method controls hydraulic pressure in the variable transmission, and thereby reduces the likelihood of noise in the variable transmission under certain driving conditions. The hydraulic pressure is controlled by changing the inclination angle of a movable swash plate. The driving conditions which prompt the control system may include: (1) A signal voltage of a throttle sensor indicates the throttle opening is lower than a first threshold value; (2) A vehicle speed is over a second threshold value; (3) An acceleration is over a third threshold value; (4) An engine speed is below a fourth threshold value; and (5) Conditions (1) through (4) last for a predetermined period of time.