HYDRAULIC PRESSURE CONTROLLING SYSTEM OF CONTINUOUSLY VARIABLE TRANSMISSION

摘要

PURPOSE: Hydraulic pressure control system for a continuously variable transmission is provided to prevent back moving by preventing hydraulic pressure from being supplied into a reverse brake. CONSTITUTION: Hydraulic pressure control system of a continuously variable transmission comprises a clutch control valve(190) supplying line pressure into a manual valve; a control unit isolating a passage connected to a reverse brake; a first port(191) receiving hydraulic pressure through a back moving pressure conduit of the manual valve; a second port(192) supplying the hydraulic pressure into the reverse brake; a third port(193) supplying the hydraulic pressure through a front moving pressure conduit; a fourth port(194) supplying the hydraulic pressure by being duty controlled from a first solenoid valve; a first land(198) closing or opening the first port; a second land(199) mounted on a valve spool; and a safety valve(190) having a spring member(197).