Modeling of the worm cutter in the process of cutting the gears

Abstract

This work offers a new approach to graphical modeling of worm cutter parameters, based on analyses and synthesis of simple kinematic movements, causing its cutting elements a single move and displacement when placing metal into a hollow between spikes of the gear, which is being cut. It is one of the most difficult cutting and shaping processes, combining four kinematic movements – rotation of the cutters, their axial feed, rotation of the billet and a constructive move – displacement of cutting elements, located on the principle worm helix along the cutter axis. The modeling difficulty is that the cutting surface constantly changes its location and form in relation to the spikes. This surface is formed on the billet as a kind of a transition surface between the untreated surface, the partly treated surface and the partly treated hollow between the spikes of the gear, which is being cut. Its formation is participated by all the spikes, which have performed the cutting during all the time before a certain moment. Continuous change of the transition surface shape and size determines the shape and size of the shavings and the cross-sectional parameters of the spikes slices and the tool blades, and its reproduction is a base for a correct quantitative assessment of the cutting parameters of individual blades and spikes of the cutter. In its turn, complete and authentic information about the cross-sections and the shape and size of metal layers cut during the spike milling is a base for calculating and analysis of the cutting power, the friction force, the thermal processes, fluctuations and vibrations. The algorithm of an instant surface formation between the gear spikes and the shavings 3D geometry on all of the active spikes of the tool are realized in AutoCAD graphic system. Here are given the results of computer modeling of the shavings when using the Archimedean cutter with counter feed. Complete information about geometrical structure of the cut off layers creates the base for a detailed and system modeling of this process abreast the separate warm cutter rails, the spikes and the blades. In combination with intensity of the plastic deformation data, the tension and the temperature received in Deform system for a certain spike milling condition, the parameters of the cut layers data referred in this work, create the condition for thermo prognostication and the cutting elements waste, their power load, strength protective coatings, cutting force and temperature transition processes, optimum technological processes of spike milling projecting and its managing.