Steuersystem für stufenloses Getriebe

摘要

A control system controls a line pressure applied to a CVT upon taking account of a centrifugal pressure caused by a rotation of pulleys. The control system determines whether the centrifugal pressure is greater than a predetermined value only by which the pulley transmits an input torque from an engine. When the determination is affirmative, a lower limit of a duty ratio for operating a line pressure control valve is switched from a lower limit of a linear range to 0% duty ratio. Therefore, an actual transmission ratio control range is expanded while preventing an undershoot of the line pressure.