Steuervorrichtung zum Herunterschalten für ein automatisches Getriebe

摘要

A downshift control device for an automatic transmission is provided in which the transmission is shifted down by releasing an oil pressure from a first engaging element that has been engaged while applying an oil pressure to a second engaging element that has been released. Thus downshift control device includes power-on downshift determining mechanism, gear-ratio detecting mechanism for detecting a gear ratio that changes during power-on downshift control, downshift released pressure control mechanism for generating a command to increase the pressure released from the first engaging element to a released pressure control actuator when the detected gear ratio reaches a first predetermined gear ratio, and downshift applied pressure control mechanism for generating a command to increase the pressure applied to the second engaging element to an applied pressure control actuator when the detected gear ratio reaches a second predetermined gear ratio that is larger than the first predetermined gear ratio and is established just before completion of shifting.