| 摘要 |
PROBLEM TO BE SOLVED: To prevent the occurrence of a trouble that, in a conventional working vehicle, though deceleration is effected by decreasing the number of revolutions of an engine during turning, when it is set that a working machine is automatically raised in linkage with steering operation, deceleration is not effected unless it comes to a time right before completion of turning, and smooth turning is sometimes impracticable, and when deceleration is effected at a low speed working time, work precision, on the contrary, is reduced or smooth turning is sometimes interrupted. SOLUTION: An automatic transmission mechanism is provided with a straight advance state detecting means switch 48 to detect whether steering is in a straight advancing state and a steering operation speed detecting sensor 44 to detect a steering operation speed. This mechanism is constituted such that when it is detected by a straight advance state detecting switch that steering is in a straight advance state, when a detecting value by a steering operation speed detecting sensor 44 is higher than a detecting value by the steering operation speed detecting sensor 44 is higher than a predetermined set value, a car speed is automatically changed to a predetermined speed, and the operation state of an automatic transmission mechanism is rendered effective or ineffective. |
