МАТЕМАТИЧЕСКОЕ МОДЕЛИРОВАНИЕ В ИССЛЕДОВАНИЯХ ШЕРОХОВАТОСТИ ПРИМЕНИТЕЛЬНО К ВНУТРЕННИМ ПОВЕРХНОСТЯМ

Abstract

The article considers the problems of mathematical modeling roughness of surfaces obtained in the cutting process. Roughness is related with the technological parameters of the system “machine-fixture-tool-workpiece” and the problem of fine finish of internal threads. There have been analyzed the existing mathematical models of finished surface roughness and stated the need to develop a mathematical model of internal surface roughness. There has been worked out a mathematical model of threaded profile roughness of the internal thread made by the tap in the details made from high-strength corrosion-resistant DI-8 grade steel that is popular in ship equipment building, by using methods of planning experiments. Geometric parameters of the tap cutting part have been taken as independent: angle of the intake cone, face and rear grinding angles. There have been listed parameters for qualitative evaluating and rating sharpened surfaces that are given in GOST 2789-73: altitudinal, step, profile bearing surface parameters. A mean-square deviation of microroughness profile was suggested to use as a roughness parameter. Impression method was used to evaluate roughness, light section device МИС-11 of V.P. Linnik was used to measure mold surface roughness. The method of planning experiments of predicting the roughness of internal surfaces has been found efficient. Theoretical studies are based on metal cutting methods, as well on methods of experiment planning with application of regression analysis; experimental research was conducted under laboratory conditions by using a computation machine. The research results allow to greatly improve the surface finish technologies in shipbuilding.