SPEED CHANGE CONTROL DEVICE OF AUTOMATIC TRANSMISSION

摘要

PURPOSE:To prevent a judder and a shock at the time of switching from a neutral range to a reverse step to set an auxiliary speed change part to a high speed step or to a forward step having a hill holding function. CONSTITUTION:This is a speed change control device of an automatic transmission A furnished with a gear row serially connecting an auxiliary speed change part capable of switching to a high speed step and to a low speed step and a main speed change part 2 capable of setting a plural number of speed change steps including a reverse step and capable of setting the auxiliary speed change part 1 to the high speed step at the time of setting the reverse step. Additionally, it is furnished with a reverse range detection means 3 to detect that it is switched from a neutral range to a reverse range, an input engine speed detection means 4 to detect input engine speed of the automatic transmission A and a high speed step indication means 5 to set the auxiliary speed change part 1 to the high speed step in the case when the input engine speed becomes lower than specified engine speed after setting the main speed change part 2 as it is switched to the reverse range.