Oil pressure control system for continuously variable transmission.

摘要

A control system for a continuously variable transmission has a spool valve (40) for controlling the line pressure of oil supplied to a cylinder of a pulley device to change the transmission ratio. An idle switch (86) and driven pulley speed sensor (72) are arranged to detect a condition in which the motor vehicle is decelerated while the engine is coasting, and the spool (42) of the line pressure control valve is then shifted by controlling the amount of oil supplied to the chambers of the valve, so that the line pressure increases in accordance with the magnitude of the deceleration.