| 摘要 |
PURPOSE:To prevent dry blow-up from occurring by detecting a variation in an actual gear ratio from input-output shaft rotational frequency, and for a period when this variation is within the specified range, maintaining a friction factor, varying from the clamp side to the release side, in a clamped state. CONSTITUTION:An automatic transmission control unit 19 selectively clamps and releases a frictional engaging element 8 of a gear shifting mechanism 7 according to a specified shift characteristic curve on the basis of each signal out of a throttle sensor 14 and a car speed sensor 15 and performs a speed change. In this case, a variation in an actual gear ratio is calculated from rotational frequency Nt of an input shaft 5 to be detected by a turbine speed sensor 16 and rotational frequency of an output shaft 6 or a car speed signal, and for a period when this variation is within the both upper and lower gear ratio reference values, a friction factor of the frictional engaging mechanism 8, varying from the clamp side to the release side, is maintained in a clamped state. Thus, supposing that engine output tries to start up to a high output range by foot operation from power-on, any blow-up of an engine can be prevented from occurring. |
