621.941.08 A. V. Isaev, S. V. Bushuev, and V. B. Romanov A technique of predicting the parameters of the microtopography of a surface is presented. The results are confi rmed by measurements of the roughness of the surface of an intricately shaped part produced by means of turning.Quality control of the surface of a part with a contoured profi le represents a complex problem [1]. Prediction of the roughness of a surface on the initial stages of technological conditioning of a plant makes it possible to substantially simplify the process of producing parts in accordance with technical requirements [2]. The present article presents a technique of predicting the parameters of microscopic irregularities in the treatment of intricately shaped bodies of revolution. Through the use of the conclusions of [1, 2], it becomes possible to predict these parameters in different sections of a part (cylindrical, conical, or shaped on the basis of an arc of a circle or any other curve) based on the form and parameters of the cutting edge of a tool, disregarding deformation of the tool and the stiffness of the machine [3]. Experiments that include fabrication of four intricately shaped parts in different cutting regimes with subsequent measurement of the parameters of the microtopography on equipment of the Time-Sharing Center at STANKIN were performed in order to confi rm the capabilities of the technique.The irregularities of a surface at the microlevel that arise when working a part and that are caused by different parts of the cutting edge of a tool are different [4,5]. In the present article, we will consider exclusively cases of working by a tool in which the smooth angle ϕ in plan exceeds the auxiliary angle ϕ 1 . The types of forming of the microtopography when working differently shaped parts are limited by the ranges of feed rates of the tool [6,7].The roughness parameter R a when working a cylindrical inner or outer surface by a tool with null vertex radius r is found by means of the formula R a = S/[2(cotϕ + cotϕ 1 )],where S is the feed rate, mm/rev. It is preferable to apply this formula in roughing with cutting depth substantially greater than the radius r. The precision of the prediction of the parameter R a may be increased with the use of relationships that take into account the infl uence of r on the conditions under which residual irregularities are formed [8]. The conditions of formation of the microtopography are expressed by inequalities that limit the range of feed rates in which the formation of residual irregularities is caused by different sections of the cutting edge [9].When working a cylindrical section by a tool with r ≠ 0, the following formulas are used to predict R a :

No abstract

No abstract

No abstract

No abstract