| 摘要 |
PURPOSE:To ensure a certain measure of running by holding a reduction ratio at a preset given value even when defective operation occurs in a shift control solenoid valve unit for controlling the shaft of a continuously variable transmission. CONSTITUTION:A mode switching valve 60 is located in a state to be connected to a shift control solenoid valve unit 70 to control operation of a shift servo unit 30 for controlling the reduction ratio of a continuously variable transmission TM. The mode switching valve 60 is capable of selecting and switching a normal mode wherein operation of the shift control servo unit 30 is controlled by the shift control solenoid valve unit 70 and a trouble mode wherein, during defective operation of the shift control solenoid valve unit 70, the shift control servo unit 30 is fixed at a given position and a reduction ratio is set to a given value. Further, when switch to the trouble mode is effected by means of the mode switching valve, a plurality of reduction ratios can be set according to a shift range set by a shift lever 55. |
