| 摘要 |
PURPOSE:To perform automatic switch operation of the steering control mode of a traveling working vehicle according to a work and a non-work. CONSTITUTION:Right and left front wheels 6 and 6 and a right and left rear wheels 7 and 7 of a running vehicle to which a rotary tiller is elevatably coupled are formed such that the right and left wheels are steered through respective power steering mechanisms 16 and 17. The front and rear power steerings 16 and 17 are provided with angle sensors 24 and 15, respectively, to detect the respective steering angles of the front wheel 6 and the rear wheel 7. Through operation to switch a work mode by a work mode change-over switch 27 and from detecting values from the two angle sensors 24 and 25 and a detecting value from an elevation sensor 26 to detect the elevating state of the rotary tiller, the vehicle is held in a crab operation mode only when it is confirmed by a control device 23 that the rotary tiller is in a lowering state and the front and rear wheels 6 and 7 are in the same direction and have the same rotation angle. At other time, selection to a front wheel steering mode and four-wheel turn steering mode is practicable. |
