Investigation of the Accuracy of the Height Dimensions of Forgings for Cold Volumetric Stamping Processes by the Computational and Analytical Method

Abstract

In mechanical engineering, product quality indicators are inextricably linked with the accuracy of machining parts. The dimensions, shape and location of the surfaces obtained during processing determine the actual gaps and tightnesses in the joints of machine parts, and consequently, the technical parameters that affect the quality, reliability and economic performance of production and operation. Very often in practice, the achievable accuracy of processing, including cold volumetric stamping (HOS), is judged by the accuracy tables contained in special reference literature. Such tables contain indicative data on achievable accuracy for various technological operations, obtained by systematization of direct long-term observations in production conditions. However, the peculiarities of individual operations do not allow us to give a conclusion about the accuracy of stamping by analogy with other operations, since there is no comprehensive similarity between them. In particular, the sizes and shape of the initial blanks differ, mechanical the properties of their material, the friction conditions in the die cavity, the characteristics of the press used and other technological factors. Thus, taking into account the listed circumstances, in each specific case it is necessary to calculate the accuracy of processing, which should have the ultimate goal not only to obtain a numerical result, but first of all to disclose the mechanisms of accuracy control. The calculation of the processing accuracy should be carried out taking into account the methods of obtaining dimensions and methods of setting up the technological system. The article is devoted to the computational and analytical method for calculating the forging accuracy based on the application of the theory of parametric sensitivity.