CONTROL DEVICE OF AUTOMATIC TRANSMISSION

摘要

PURPOSE:To supply enough engaging pressure to a friction element without damaging the pressure regulating accuracy in an automatic transmission including a pressure regulating valve installed in an engaging pressure supply path communicating with a designated friction element to reduce the control initial pressure to a designated pressure and a solenoid valve for controlling the control pressure of the pressure regulating valve. CONSTITUTION:The control pressure from a first linear solenoid valve 81 is introduced to a control valve 79 which is connected to an intermediate brake 26 in a main transmission for reducing the line pressure to be regulated to a designated engaging pressure, and some of engaging pressure supplied to a coast brake 27 is supplied to one end port 79b of the control valve 79 to limit a pressure regulating function.