| 摘要 |
PURPOSE:To reduce a speed change shock in the case of a downshift following the speed reduction of a car by correcting hydraulic pressure supplied to a frictional engaging element on the deceleration of the car. CONSTITUTION:A detection signal issued from a rotational speed sensor 37 is sent to an electronic control unit to control the operating state of an engine 11 for calculation of the deceleration of the car. The auxiliary duty rate to the basic duty rate of a hydraulic control valve to control engaging hydraulic pressure to a frictional engaging element on an engaging side is read out of a map according to the value of the deceleration of the car for the calculation of a target duty rate. Thus, in the case of a downshift in a rapid decelerating state, tone hydraulic pressure supplied to the frictional engaging element on the engaging side is established to somewhat higher value. In the case of the downshift following the slow deceleration, the hydraulic pressure supplied to the frictional engaging element on the engaging side is established to somewhat lower value. Thus the frictional engaging element on the engaging side engages timely for the downshift executed under a speed change shock. |
