Hydraulic control system for continuously variable transmission in vehicles, controls the valve to raise the pressure from primary to secondary level, when shift to high transmission side is not accomplished

摘要

The system includes a transmission mechanism (10) provided with a set of pulleys (16,26) bridged by a belt (24). A shift control valve operated by an actuator supplies reduced pressure to chamber in controller, operates the valve to raise the pressure from primary to secondary level, when shift to high transmission side is not accomplished. The width of pulleys is being variable by the pressure applied to the chambers of respective pulleys.