Mal'kova

pp. 56-68

pp. 101-110

pp. 65-73

Based on the developed geometrical model an experiment is conducted to calculate the values of tooth profile angles of thread milling cutter with helical flutes at variation of five factors in the established factorial space. When planning the experiment the full central composite draft has been elaborated in the coded form for five factors at three levels taking into account the orthogonality and the impossibility to conduct repeatedly experiments in the chosen points. Mathematical models are developed to calculate the tooth profile angles of thread milling cutter with helical flutes allowing to obtain the values of angles depending on a pitch of thread, a cutter diameter, a rake angle, an angle of lead of helical flutes, and a back angle. Calculation of the profile angles made according to polynoms for all combinations of factors has shown that an error of calculated values in comparison with the values obtained using a geometrical model do not exceed a tolerance for a half of tooth profile angle according to GOST 1336-77.

This article considers a possibility and an algorithm of the mathematical study of polynomial dependences which are used for describing characteristics of machining. The authors describe advantages of polynomial dependences obtained on the basis of a complete factorial experiment in multidimensional parameters spaces. For illustrative purposes, an analysis of energy consumption during two-stage lathing was carried out on the basis of the obtained polynomial dependence of the tangential cutting force on processing factors. The influence of the specified factors was established a priori on the basis of conducted experimental studies or literary sources. Conditions and results of all the conducted experiments are presented in this paper along with the algorithm for determining the minimal value of energy consumption.