Assembly quality improvement using selective assembly

Abstract

Quality is an important aspect in any manufacturing process. newlineCustomer wants the product with high quality at cheaper cost. The quality of the newlineproduct depends on the quality of its assembly. The quality of the assembly newlinedepends on its functional performance. The functional performance of the newlineproduct depends on conformance to the dimensions of its mating components newlineand tolerance or clearance between them. The quality of an assembly can be newlineimproved by manufacturing the components to their closer tolerances with newlineimproved processes and better machines. It may not be possible due to newlineeconomical aspect and also technically not feasible beyond certain limits. newlineIn such situations, selective assembly method can be used to improve newlinethe quality of the assembly with available resources. Selective assembly method newlineis used where the components are manufactured with wider tolerances and newlinerequires high precision assemblies. In this method, the mating components are newlinegrouped according to their size and the components in the corresponding groups newlineare assembled interchangeably. In an interchangeable assembly the mating newlinecomponents are randomly selected and assembled. In this case there will be no newlinesurplus parts but the assembly tolerance / clearance variation will be high. In newlineconventional selective assembly, the variation is grouped. It will be less within newlinethe group. However, the population variation will be the same. newlineIn this research, a new selective assembly model is proposed for newlineattaining specified tolerance / clearance and also minimizing the surplus parts. In newlinethis proposed model, selective group combinations are used to get maximum newlinenumber of assemblies for the specified tolerance /clearance. Genetic algorithm is newlineused to get the best group combinations along with the number of assemblies to newlinebe made in each combination to produce maximum number of assemblies. The newlineproposed model is applied for a linear assembly and a radial assembly. In newlinecontinuous manufacturing environment, the surplus parts will get accumulated newlinecontinuously newline