Technological support for the accuracy of the assembly of mechanisms

Abstract

Abstract The technological process of ensuring the accuracy of assembly of mechanisms is formally a sequential summation of primary production errors and an analysis of the obtained generalized values in order to develop and implement specific technological methods aimed at meeting the technological requirements for the accuracy of the relative position of parts. When ensuring the accuracy of the crank mechanisms for the misalignments of the axes of the piston and cylinder, assembled from specific, randomly received component parts, production personnel deal with strictly defined crankshafts, connecting rods, pistons, cylinder blocks, and, consequently, with one or another manufacturing errors. Ensuring the accuracy of the assembly of these parts in a mathematical sense with such a sequence will be nothing more than an algebraic summation of the primary errors and the compilation of their numerical values with the maximum permissible values. A different situation arises in the implementation of assembly technological processes with the automatic achievement of precision parameters by varying individual parts from their total number, which are at the disposal of designers and entered into computers as initial information. Since in this case one has to deal with fairly representative aggregates, the final result of combining parts into nodes will be satisfied with a greater or lesser probability, especially when the sum of the maximum deviations of the constituent links (parts) is not equal and not less than the maximum permissible total values. Obviously, the probability of release from the assembly site of high-quality products with automatic support and the accuracy will be determined both by the modules of individual deviations and by the distribution laws of actual deviations within the tolerance field.