| 摘要 |
PROBLEM TO BE SOLVED: To provide a running speed change control device of an agricultural tractor capable of performing gear shift to a gear position corresponding to the condition without troublesome speed adjustment. SOLUTION: The running speed change control device 1 of an agricultural tractor comprises a main speed change mechanism d having a plurality of gear positions capable of selecting the transmission gear ratio for a vehicle speed zone in service among a plurality of vehicle speed zones set to be in a speed change range by a running transmission, and a speed change command means to command the speed change of the gear position of the main speed change mechanism d. The speed change command means has an automatic gear change means to count (S7) the maintenance time of the gear position selected when a machine runs, store (S11) the longest gear position when the service of each vehicle speed zone is completed, and command (S12) the speed change to the gear position related to the storage when the corresponding vehicle speed zone is used next. COPYRIGHT: (C)2004,JPO&NCIPI |
