Patent ID: 8226507

Claim:
A control device for a continuously variable transmission having a speed change pulley and a tightening pulley around which a power transmission element is wound, comprising: a speed change control valve provided between a hydraulic supply source and said speed change pulley for adjusting a speed change control pressure supplied to said speed change pulley; a tightening control valve provided between said hydraulic supply source and said tightening pulley for adjusting a tightening control pressure supplied to said tightening pulley; target gear ratio setting means for setting a target gear ratio on the basis of a running condition; actual gear ratio calculating means for calculating an actual gear ratio on the basis of a rotation speed of said speed change pulley and said tightening pulley; feedback control means for feedback-controlling said speed change control pressure on the basis of a deviation between said target gear ratio and said actual gear ratio; failure detecting means for detecting failure of said tightening control valve; and speed change region setting means for limiting a setting region of said target gear ratio during failure of said tightening control valve so as to set the target gear ratio to the value achievable as the actual gear ratio.