METHOD OF SELECTIVE ASSEMBLY IN SMALL-SCALE PRODUCTION

Abstract

The article investigates the method of selective assembly in small-scale production. It is noted that selective assembly is a way to achieve a high-precision gap between two parts of the assembly. The article proposes to illustrate the idea of selective assembly in small-scale production on the example of a sleeve and a shaft assembly. The general principles on the basis of which the selective method is realized are formed. The essence of the group interchangeability method is separated, which consists in the fact that the parts of the connection, made within the technologically possible tolerance, are sorted
before assembly into several groups, and then assemble the parts into groups. It is emphasized that selective assembly is used, firstly, when you want to increase the accuracy of the joints without reducing the tolerances for machining the parts to be joined, and secondly, when you want to expand the tolerances for machining to cost-effective while maintaining the specified accuracy. A binary linear system of selective addition in small-scale production is proposed, which is a special case of a multidimensional problem known as the problem of assigning a multi-index. Describes the essence of the method of selective addition, in which the total number of variable solutions and the linear system of selective addition can be solved for a globally optimal solution using a branching algorithm, with lower limits being obtained by solving linear equations. The mathematical component is formed and the influence of the mechanism of check of the collected production on cost of final quality is described. It is substantiated that the method of selective assembly in the conditions of small-scale production much improves the quality of assemblies than one hundred percent verification of the results of random assembly despite the cost of selective assembly.