TRACTOR

摘要

PROBLEM TO BE SOLVED: To prevent the generation of hunting phenomenon comprising repeated lifting and lowering of a working part and improve the work accuracy and stability in a tractor provided with a means for the automatic control of tilling depth and a means for the control of the rotary load on the engine. SOLUTION: The tractor is provided with an automatic tilling depth controlling means to lift or lower the working part 3 based on the tilling depth detected by a tilling depth sensor 9 and a rotary load controlling means for engine to lift the working part 3 by a prescribed height according to the lowering of the rotational speed of the engine. The variation of the rotation of the engine is judged after the lifting of the working part 3 and, when the rotation of the engine is in stable state, the restoration to the automatic tilling depth controlling mode is restricted and the working part 3 is waited at the lifted position.