Calculation model of technological process of soil crumbling by means of tillage working organs

Working organs being used currently for subsurface tillage do not comply with agrotechnical requirements. In particular, the crumbling of soil layer is unequal across the width of cutting plane of working organ. The scientific hypothesis is that variable cutting angle along the length of blade improves the crumbling of soil layer. The mathematical model of interaction between the soil and a wedge is proposed. As the result, the theoretical dependencies of resistance force of soil to destruction and of thickness of shear layer on the setting angle of tillage tool are obtained. A set of dihedral wedges with different angles of inclination has been used in experimental studies. The tests have been performed in media with a wide range of physical and mechanical properties (ordinary humus, sand, clay). It is determined experimentally that all media interacting with the wedge have some common characteristics depending on the parameters of wedge, in spite of differences of physical and mechanical properties and the appearance of layer formation. The experimental dependence of equivalent stresses on cutting angle of the wedge is obtained. Experimental and theoretical results agree well with each other. On the basis of these studies, the working organs with variable cutting angle are developed. It is revealed that the blade with variable cutting angle creates more tension in the soil layer than a blade with constant cutting angle. It is experimentally confirmed that the working organs with variable cutting angle along the length of the coulter crumble the layer by 20-50% better than serial working organs. The economic effect of the introduction of working organs with variable cutting angle is 200-1300 rubles per hectare of cultivated area.

soil fracture model, tractive resistance, soil crumbling, dihedral wedge, interaction between working organs and soil, optimal parameters