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

摘要

A control system for an infinitely 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 to change the transmission ratio. The line pressure control valve has chambers. By controlling the pressure of oil supplied to the chambers in accordance with a desired line pressure, the spool is shifted, so that the line pressure is controlled.