| 摘要 |
PROBLEM TO BE SOLVED: To form an automatic transmission at a little cost by allowing two switchingly coupling devices used selectively by a switchingly adjusting element of pressure medium operating type to be controlled into two stably switched condition and two unstably switched condition by the use of three pressure systems and two multi-route valve devices. SOLUTION: In order to supply pressure to two switching elements SE-1 and SE-2 by selectively turning on or off these switching elements when a transmission stage of a transmission device of planetary gear structure is selected, the transmission device comprises a pressure system 4 capable of setting a pressure to a system pressure and pressure systems 5 and 6 capable of setting a pressure to an adjustable working pressure. A common second multi-route valve 17 is provided in the pressure routes 4 to 6, and a valve position is switched to S2 when a regulating element 26 of the second multi-route valve is energized by a control pressure through a pipe 13. Under that switched condition, for example, when the transmission capacity of the element SE-2 is increased larger than that of the element SE-1, a first multi-route valve 12 is switched to a position S2. |
