GEOMETRIC MODELLING OF BIT SURFACE GUIDELINE OF CHISEL TOOL WORKING BODY

Abstract

The mathematical model for shaping the guiding surface of the working body bit of chisel tool for soil cultivation has been proposed. It has also been indicated, that chisel tools application when growing crops contribute to the formation of appropriate conditions for plants growth and development .A significant effect from chisel tools application is being achieved on the soils having signs of water or air erosion processes due to creating the optimal water and air soil regime while maintaining stubble on the field surface.Attention is drawn to the fact that in order to reduce the chisel tools traction resistance, considerable attention is paid to conducting research to define the optimal geometric parameters of the shape and position of their working bodies.

The working bodies of the chisel tools are equipped with chisels, having various design solutions with the corresponding geometric parameters of their shapes and positions. It has been proved that chisel tool traction resistance largely depends on the geometric parameters of the shape of the bit curved guide surface. Applying the bits having surface in the form of plane, as the previous research showed, increases the effort to mode the separated soil layer from the massif.

It has been defined that the task of optimizing the parameters of the bits hape is to define such a bit shape, that it would provide a decrease in the initial alue of the relative velocity of the soil particle along its surface to the minimum value at its final movement along of the surface. By means of mathematical modelling of soil movement along the bit surface, non-linear functional has been obtained, that reflects and arbitrary vector set characterizes the interaction of a soil particle with the guide bit surface in the set of real numbers. The minimum value of a defined functional ensures the emergence of a continuous function of the guide surface of the bit, at which the velocity of the soil particle at the and of its interaction with the surface will be zero. It has been noted that the calculus of variations methods for finding the optimal solution of the obtained functional are very complicated, therefore, the search for the optimal function should be carried out among the polynomials.

Key words: chisel working body, bit, guide, surface, shape parameters, relative speed, functional, soil.