HYDRAULIC CONTROLLER OF MULTISTAGE AUTOMATIC TRANSMISSION

摘要

Solenoid valves such as linear solenoid valves (SL1-SL5, SLU) are constituted as normal by closed solenoid valves. A first clutch apply relay valve (34) outputting a forward range pressure P_D as a reverse input pressure in the case of solenoid all off, and a second clutch apply relay valve (32) switched between a left half position for inputting the reverse input pressure reversely to a discharge port SL1d and a right half position for inputting the reverse input pressure reversely to a discharge port SL2d are provided. The second clutch apply relay valve (32) is set at right half position in the case of normal engine start and locked based on a lock pressure by passing a line pressure P_L as the lock pressure, and is set at left half position for interrupting the lock pressure after engine restart in case of solenoid all off. Consequently, a transmission is fixed to a relatively high stage of speed when solenoid all off state occurs while a vehicle is traveling, and the vehicle can be restarted.