CONTROL DEVICE FOR AUTOMATIC TRANSMISSION

摘要

PURPOSE:To generate a good performance of shift operation with less shocks by providing possibility of forming a rack pressure properly corresponding to the shifting direction in either of the shifting modes in which the shift motions in opposite directions are made through engaging and disengaging of a friction element. CONSTITUTION:A 1-2 accumulator 74 is connected with a servo apply line 118 leading to an apply port 45b at the servo piston 45a of a 2-4 brake 45. At the time of 3-4 shifting where the 2-4 brake 45 is put in engagement, the back pressure is supplied to the secondary back pressure chamber 74b of the 1-2 accumulator 74 through the first shift valve 63 which is to switch the supply and exhaust of the servo apply pressure to/from the apply port 45b.