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. A hydraulic circuit is provided for supplying oil to a port of the line pressure control valve so as to shift the spool. A pressure reducing valve is provided in the hydraulic circuit for keeping the pressure in the circuit constant and a control valve is provided in the hydraulic circuit so as to control the quantity of the constant pressure oil supplied to the end of the spool.