| 摘要 |
PURPOSE:To make it possible to run safely even if a solenoid becomes out of order in running, and yet to start again by providing an oil chamber for reducing speed for making speed changing direction change over to reducing speed side and a signal pressure generating means for generating signal pressure to supply it to the oil chamber for reducing speed. CONSTITUTION:When something unusual occurs to the solenoid of a first electromagnetic valve 266, and if it is in an increasing speed mode of change gear ratio control, a speed change direction changeover valve 262 is placed in an increasing speed side position, and if it is in a decreasing speed mode, the speed change direction changeover valve 262 is placed in a reducing speed position, then speed change gear ratio control for making actual input shaft revolution speed coincide with targeted revolution speed is continuously performed. In this way, usually, if solenoids of the first electromagnetic valve 266 and a second electromagnetic valve 268 become out of order, a CVT becomes in slowly increasing mode, therefore even if solenoid trouble is generated during high speed running, it is possible to continue running, but when change gear ratio is required to be switched to reducing speed side at the time of starting vehicle and so on requiring large driving force, a signal pressure Psol5 generated by a fifth electromagnetic valve 392 is supplied to an oil chamber for reducing speed 283 of the speed change direction changeover valve 262, thus the speed being reduced, and changed. |
