| 摘要 |
PROBLEM TO BE SOLVED: To accurately control the transmission ratio even at low oil temperature time by driving a shift control valve on the basis of the target transmission ratio and the actual transmission ratio from a mechanical feedback means, and controlling a flow rate and the direction of a hydraulic fluid supplied to a hydraulic cylinder connected to a trunnion. SOLUTION: A toroidal continuously variable transmission 2 and a constant transmission 3 including a power roller sandwiched between input and output discs so as to be freely tiltable are connected to an output shaft 1 in a parallel state, and output shafts of these transmissions 2, 3 are connected to an output shaft 6 via a planetary gear mechanism 5, a motive power circulating mode clutch 9 and a dirctly coupled mode clutch 10. In controlling a shift of such transmissions, a shift control valve using a step motor 36 as a displacement driving source is provided to control the supply direction and hydraulic pressure supplied to a hydraulic cylinder for tilting the power roller. When a vehicle driving state becomes a preset state, the step motor 36 is controlled in driving according to preset creep torque and the actual transmission ratio.
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