| 摘要 |
PURPOSE:To improve the reliability of the controller by preventing a subtransmission to carry out speed change, even if one of the solenoid valves is switched, by permitting two solenoid valves to be operated and executing the speed change of the subtransmission when the supply and discharge state of the corresponding oil passage is switched. CONSTITUTION:Switching control for a subtransmission is carried out by a selecting valve 10, and when both of the first and second solenoid valves S4 and S5 are operated, the supply and discharge state of the hydraulic pressure into each control port 11, 15 of the selecting valve 10 is varied, and the valve piece of the selecting valve 10 shifts, and the supply state of the hydraulic pressure into the subtransmission is varied to select the high and low states. When any of the solenoid valves is put inoperative or operated singly, the selecting valve 10 maintains the present state by the feed and discharge states of the hydraulic pressure by an oil passage through another solenoid valve, and the electrical switching control for the subtransmission can be performed with high reliability.
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