| 摘要 |
PURPOSE:To make it possible to facilitate the drive of a vehicle running on a road, by providing a means for locking wheels which are rear in the travel direction of a vehicle, in a impossible steering condition at a rectilinear travel position when front and rear working machines are both raised and the operator takes his seat. CONSTITUTION:When the operator sits on a seat 24, a seat detector 50 is turned on. Further, when front and rear working machines 27, 28 are both raised, an elevation detector 49 is turned on. With this arrangement, a signal from a steering instructing unit 42 is cut off by means of a gate circuit 51, and a rear wheel locking means 54 is energized. That is, a comparator 57 compares a signal from a turn angle detector 55, and a discriminator 58 judges the direction of return to energize one of solenoids 46, 48. With this arrangement, the rear wheels returns to the rectilinear position to lock a clocking cylinder 19. Accordingly, the front wheel 2 is alone steered during running on a road to facilitate the drive of the vehicle. |
