Soil–Tool Interaction Investigations of the Disc Cutter with Adjustable Setting for a Planting Machine

The paper outlines soil–tool interaction investigations according to parameters of the trencher disc cutter with a variable installation angle relative to the rotation axis that ensure the required trench shape and dimensions. The research results make it possible to improve the quality of the technological process for obtaining the needed trench shape. The movement of soil particles on the knife surface and after their removal was considered using the principles of soil mechanics, mathematical analysis, and computer (3D) modelling taking into account centrifugal force, gravity and friction. Research has shown that the soil particles’ movement is spatially complex and can be described by parabolic dependencies when projected onto coordinate planes. It is proved that changing the angle of installation of the disc in the range of 90–80° allows the furrows’ width to be adjusted within the range of 0.1–0.5 m while maintaining the required depth of cultivation. The reduction indicators of trench depth that are dependent on changing the disc installation angle were also determined. The obtained dependencies, design and technological recommendations can be used in designing of planting machines for garden and forest crops, as well as in the justification of rational operating modes for them in intensive horticulture conditions.