SPEED CHANGE CONTROLLER OF AUTOMATIC TRANSMISSION

摘要

PURPOSE:To enable a tie-up in the case of manual downshift to be reliably avoided. CONSTITUTION:A speed change controller of an automatic transmission A is provided with a frictional engaging device 1 for engine brake and a valve mechanism 2 to be electrically controlled, and for selectively supplying oil pressure to the frictional engaging device 1. And a speed change judging means 3 for judging the speed change into the speed change stage with which the frictional engaging device 1 is engaged and an engagement delaying means 4 for maintaining the frictional engaging device 1 in the releasing state until the fixed period determined on the basis of the traveling state including any one of car speed, throttle opening and speed change stage as a parameter passes after commanding the speed change into the speed change stage when the speed change into the speed change state is judged are provided. Accordingly, the engagement timing of the frictional engaging device for engine brake is accurately controlled, so as to prevent a tie-up in the case of downshifting into the speed change stage for bringing engine brake in its play.