GEAR SHIFT CONTROL DEVICE FOR AUTOMATIC TANSMISSION

摘要

PURPOSE: To shorten the length of a second shift valve and to reduce the size of a gear shift control device by a method wherein when an output oil pressure is not exerted on a second shift valve from a first solenoid valve the control device is so constituted as the output oil pressure from a second solenoid valve is applied to the shift valve. CONSTITUTION: An oil passage e4 wherein the output oil pressure of a first solenoid valve d1 and the output oil pressure of a second solenoid valve d2 are exerted on a third shift valve b3 in switching directions different from each other is provided. A spring (f) is provided to be energized in a switching direction by the output oil pressure of the first solenoid valve d1. When an output oil pressure is not generated by the first solenoid valve d1 and an output oil pressure is generated only by a second solenoid valve d2, a third shift valve b3 is switched.