Patent ID: 6740005
Filing Date: 2004-05-25
Classification: B60W,F16H,Y02T,Y10T

Abstract:
A shift control apparatus of an automatic transmission of a motor vehicle to which a torque is transmitted from an engine via a fluid coupling device, the automatic transmission including a plurality of hydraulically operated friction elements, wherein a clutch-to-clutch downshift is carried out during coasting of the vehicle by releasing one of the friction elements as a release-side friction element and engaging another of the friction elements as an engagement-side friction element, comprising:a speed difference detecting unit that detects a difference between input and output rotation speeds of the fluid coupling device; and a minimal driving state controller that increases an engine speed by a controlled amount based on the difference between the input and output rotation speeds detected by the speed difference detecting unit when the clutch-to-clutch downshift is carried out during coasting of the vehicle, so that the vehicle is brought into a minimal driving state in which the engine speed is slightly higher than the output rotation speed of the fluid coupling device.