| 摘要 |
PROBLEM TO BE SOLVED: To ease a shift shock and provide a smooth engine brake by changing a shift point in downshifting in coasting according to the deceleration of a vehicle. SOLUTION: A duty ratio is feedback controlled so that a target rotational speed NTt in which a turbine rotational speed NT is set higher than an engine rotational speed NE byαto maintain the vehicle in a weak engine brake state. The shift point is calculated by taking account of the deceleration of the vehicle. At first, a coasting state is detected so that the complete stop time t17 is estimated according to the deceleration. Secondly, a point on a forth gear synchronous rotational speed DK4 in the time t13 when a second gear synchronous torational speed DK2 and NTt are crossed with each other is set to P0. A 2-1 shift point P21 is a time t12 before the point P0 by such a quantity that the first clutch C1 implements a fast quick fill so as to have a capacity. The shift points P32, P43 are decided based on the shift point P21. |
