Моделирование влияния сил закрепления на точность формы обрабатываемой заготовки с помощью метода конечных элементов

Abstract

In the article, the modeling of the impact of hold-down forces on the accuracy of the shape of the workpiece using the finite element method was carried out. The operation of mechanical processing (turning cut) of a workpiece of the body of rotation type on a milling machine with basing and fixing along the inner cylindrical surface of the workpiece is considered. The study was conducted for four different types of machine retaining devices used on machines of this group. A consistent description and illustration of the method of modeling the process of the impact of hold-down forces on the workpiece is made for each type of the device under consideration. The force constraints and effects imposed on the model are described and illustrated, the parameters of the finite element grid used in modeling are presented, the displacement profiles obtained in the modeling process and the stages of modeling the machining process are described, and the values of the largest deviations from the shape of the workpiece are determined. The results of the modeling are presented: a qualitative picture of the shape errors obtained as a result of mechanical processing — the values of the largest deviation from the roundness and the largest deviation from the cross-section profile of the workpiece to be processed, as well as the shape of the cutting obtained in the cross-section of the workpiece for each type of the devices under consideration. On the basis of the obtained results, estimates of the degree of accuracy of the shape and the relative geometric accuracy provided by the considered devices were made in accordance with GOST 24643–81. The conclusion is made about the suitability of using the considered variants of machine retaining devices for the proposed technological process according to the criterion of the provided accuracy of the shape of the processed surface. English version of the article is available at URL: https://panor.ru/articles/modeling-the-influence-of-the-fastening-forces-on-the-accuracy-of-the-workpiece-shape-using-the-finite-element-method/65043.html