AUTOMATIC GEAR FOR VEHICLE

摘要

PURPOSE:To reliably ensure running of a vehicle even when a solenoid valve fort gear shift fails. CONSTITUTION:An automatic gear shifter for a vehicle comprises a manual valve 32 coupled to a shift lever and operated; a plurality of solenoid valves 11-14 magnetized and operated according to the running state of a vehicle; a plurality of frictional fastening elements C0-C2 and B0-B3 receiving an oil pressure and selectively coupling or fixing the constituting elements of a planetary gear train- to generate a desired wheel drive force; a manual valve 32 and solenoid valves 11-14; and mechanical type switching valves 21-29 and 35-37 arranged between friction fastening elements C0-C2 and B0-B3 and switching the feed of an oil pressure to the frictional fastening elements C0-C2 and B0-B3 according to operation of the manual valve 32 and the solenoid valves 11-14 so as to selectively operate a constituting element having a relation to bring the planetary gear train into a lock state during simultaneous operation.