Control system for an infinitely variable transmission

摘要

A control system for an infinitely variable transmission has a transmission ratio control valve having a spool for controlling oil supplied to a cylinder of a drive pulley to change the transmission ratio. The transmission ratio control valve has chambers at both ends of the spool. By controlling the pressure of oil supplied to the chambers in accordance with engine operating conditions, the spool is shifted, so that the speed of changing the transmission ratio is controlled.