Determination of tractive resistance of a wide-cutting chain harrow for soil mulching

Justification. One of the prerequisites for realization of mini-till and no-till technologies is accumulation of mulch layer. High efficiency in soil mulching is shown by chain harrows, but the working tools used on them are not fully able to provide sufficient depth of cultivation, as well as crushing and mixing of crop residues with soil. Taking into account the high perspective of mini-till and no-till technologies, the research aimed at improving machines for soil mulching and in particular chain harrows is relevant

Purpose of work. Development of wide-catch chain harrow and working body providing intensification of soil mulching processes, theoretical and experimental evaluation of traction resistance of the machine.

Materials and methods. On the basis of methods of agricultural mechanics the research of traction resistance value of harrow with improved chain working organ has been carried out. The laboratory-field experiment on estimation of traction resistance value of wide-catch chain harrow was carried out.

Results. Based on the analysis of drawbacks of the standard working organ of V.I. Dvurechensky's chain harrow, it was proposed to move the ripping tooth to the fixing plate located in the center of the link. This technical solution is designed to provide better burial of tines in the soil, as well as the intensity of shredding of plant residues. It is theoretically established that the value of traction resistance of the improved chain working device, depends on the weight and the main design parameters of ripping teeth: length, tooth sharpening angle and cross-sectional diameter. The conducted laboratory-field experiments allowed to establish that at changing the working speed of the machine from 15 to 21 km/h, the value of traction resistance increases from 26.2 to 32.3 kN, respectively, with the value of tractor slip not more than 3.0%. Based on the analysis of the obtained values of traction resistance and agrotechnical indicators of work determined the rational speed of the machine, which should be 18 km / h.

Practical value of the research. The value of traction resistance of the chain harrow with the improved working organ has been experimentally determined, which allows recommending a tractor of rational traction class. The rational technological mode has been revealed.