Justification of the operating modes of the needle disk of a new design

Abstract

The preservation and accumulation of productive soil moisture in areas with insufficient moisture and subject to wind erosion does not lose its relevance. Known disc needle-like working bodies of rotary harrows, intended for surface treatment on stubble backgrounds, are mainly aimed at loosening the upper soil layer. An incorrectly selected mode of using existing needle harrows is dangerous by excessive spraying and drying out of the surface of fertile soil. In this regard, there was proposed a new technical solution for a needle disk with a changing shape of needles, which makes it possible to loosen the top layer of soil from making holes on the surface of the field. A tillage tool with needle discs consists of a hub with needles fixed on it. The disc is installed afrontal, each needle is made of a variable shape, the first half made from the base of the needle is square, and the second half is pyramidal with a top at the end of the needle. The use of such needle discs with needles, which more easily penetrate the soil make it possible to efficiently chop up crop residues and loosen the soil, which improves the quality of soil cultivation. The tests of the new needle disk against the background of perennial grasses made it possible to substantiate the main operating parameters of the new working body. For sandy loam soil with a hardness of 14,5 kPa with an agrophone of perennial grasses, such as awnless rump and alfalfa, it was found that the maximum parameter for moisture accumulation will be achieved at a speed of 7 km / h with an angle of attack equal to 0°, and loosening at a speed of 9 km/h with an angle of attack of 16°. A rational parameter, at which not only moisture accumulation occurs, but also high-quality soil cultivation, is achieved when the angle of attack is set to 4° and the speed of the unit is 7 km/h.