System for controlling the pressure of oil in a system for a continuously variable transmission

摘要

A control system for a continuously variable transmission has a line pressure control valve having ports and a spool for controlling the line pressure of oil supplied to a cylinder of a drive pulley. The line pressure control valve has chambers at opposite sides of the spool. A spring is provided between one end of the spool and a slidable spring retainer. By controlling the pressure of oil supplied to the end of the spool and the force of the spring in accordance with engine operating conditions, the line pressure is controlled.