SPEED CHANGE CONTROLLER FOR AUTOMATIC TRANSMISSION

摘要

PURPOSE:To prevent the occurrence of two speed change shocks by performing the speed change control attaining the Nth speed stage during the down-shift from the (N+1)th speed stage to the (N-1)th speed stage so that the (N-1)th speed stage is attained when the input rotating speed reaches the rotating speed lower by the preset quantity than the rotating speed synchronized with the Nth speed stage. CONSTITUTION:An electronic controller 70 first performs the speed change control during the down-shift from the fourth speed stage to the second speed stage, and it performs the speed change control attaining the second speed stage when the input shaft rotating speed Nt detected by a rotating speed sensor 78 reaches the preset rotating speed Ntset lower by the preset quantity than the rotating speed Nt3 synchronized with the third speed stage. The speed change to the second speed stage is started before the input shaft rotating speed Nt reaches the rotating speed Nt3 synchronized with the third speed stage, the input shaft rotating speed Nt does not maintain the rotating speed synchronized with the third speed stage at all, and the repeated occurrence of two continuous speed change shocks is avoided.