Effective Method of Selecting Interference Fit Based on Automated Computer Model Construction

Abstract

The proposed scientific work considers and substantiates an effective method for selecting interference fit on smooth cylindrical surfaces of parts, which can be successfully applied in automated design of fit. Based on the analysis of numerical and analytical research of the results of calculation and design of the considered joints, a flat image of a mathematical model of the area of existence of geometric parameter values in a two-dimensional coordinate system (diameter and working length of the fit) was first obtained. At the next stage of modeling many alternative i-th standard interference fits were built. Within each i-th object centers of grouping rational values of geometric parameters were defined. They are formed by crossing the largest segments of allowable ranges of changing values of diameter and working length in each of the models of sets. The position of such centers is analytically described using the mathematical apparatus of the theory of R-functions. On the considered specific example of this research, the criterion for choosing a rational standard interference fit is formulated depending on the values of geometric parameters. The meaning of this criterion is that within the flat geometric image of the model, the shortest distance is analytically determined - the segment between the points of the grouping centers of the model of set of the �-th fit and the model of the area of existence of values. The effectiveness and advisability of the formulated criterion is illustrated by comparison with other criterions obtained in previous researches of the authors. As a result of the research, it was revealed that the task of choosing a single rational design solution is significantly simplified if several criterions of one of the alternative fits coincide.