SPEED CHANGE CONTROLLER OF AUTOMATIC TRANSMISSION

摘要

PURPOSE:To appropriately control release operation of especially the first frictional element, in an automatic transmission in which the release operation of the first frictional element and jointing operation of a second frictional element are carried out simultaneously at the time of specified speed change. CONSTITUTION:An exhaust gas pressure control valve 74 in which throttle function of an orifice 74e formed on a valve body 74b is suppressed until the pressure on the low cource side drops beyond a preset pressure is set a servo apply line 121 connected from a 1-2 shift valve 63 to the apply port 45b of a 2-4 brake 45. A bypass line 145 which bypasses up and down streams of the control valve 74 is provided and a timing valve 94 is set on the line 145. This timing valve 94 is operated in the last half phase of speed change operation, and the bypass line 145 is opened.