SHIFT CONTROLLER OF AUTOMATIC TRANSMISSION FOR VEHICLE

摘要

PURPOSE:To secure the extent of stability at time of running downhill by controlling the shift speed of an automatic transmission so as to be maintained on the basis of a deviation between rotational frequency of an input shaft of the transmission and that of an internal combustion engine at a time when a decelerated driving state is judged. CONSTITUTION:When a decelerated driving state is judged on the basis of throttle valve opening by a throttle valve opening detecting means A, by a decelerated driving state judging means D, a shift maintaining means E maintains the shift speed of an automatic transmission on the basis of a deviation between rotational frequency of an input shaft of the transmission and that of an internal combustion engine. Accordingly, even if a driver separates his foot from an accelerator and fully closes a throttle valve, such a fear that shift-up operation might be busily performed in conformity with a shift line is prevented, thus operability is improved and simultaneously safety at time of running downhill is also secured.