| 摘要 |
<p>PROBLEM TO BE SOLVED: To maintain change gear ratio of a CVT(belt type continuously variable transmission) in spite of an on/off state of each solenoid valve for an up-shift and the solenoid valve for a down-shift when both solenoid valves break down. SOLUTION: A spool 92b is movably provided on a control valve 92 for controlling pressure oil to an actuator for a movable sheave of a primary pulley between a first position for supplying the pressure oil to a hydraulic actuator for the primary pulley, a holding position which does not supply and exhaust the pressure oil to the hydraulic actuator for the primary pulley and a second position for exhausting the pressure oil of the hydraulic actuator for the primary pulley with two solenoid valves SOL 1, SOL 2. Two elastically energizing means 92h, 92i whose energizing directions are in a reverse direction to each other are provided on the spool, and when two solenoid valves break down together, the spool can be positioned at the holding position by two elastically energizing means.</p> |
