JPS6439907A - Paddy field working machine - Google Patents

Abstract

PURPOSE:To facilitate automatic control of the vertical control sensitivity of a working machine independent of the traveling speed of the machine, by providing a detection mechanism to detect the relative level difference between a mud-face detection member and a member sinking in the mud. CONSTITUTION:A mud-face detection member 13 is vertically moved by sliding on the mud face M and a detection mechanism 14 detects the level of the mud face M relative to the leveling float 7 from the vertical motion of the mud-face detection member 13. The ground-leveling float 7 acts as a member sinking in the mud and varying its depth corresponding to the hardness of the mud surface M. The sunk depth D of the leveling float 7 is outputted as a detection result transmitted from the detection mechanism 14. Signals from a pressure- sensitive element 11 and the detection mechanism 14 are inputted into a controlling device 15 furnished with a micro-processor and a controlling signal is transmitted from the controlling device 15 to an electro-magnetic valve 16 operating a hydraulic cylinder 5. The controlling sensitivity is automatically and reversibly varied by a regulating means 17 toward a state to increase the controlling sensitivity when the sinking amount of the leveling float 7 detected by the detection mechanism 14 is large.