A Grouping Method to Minimize Surplus Parts in Selective Assembly

Abstract

Selective assembly is an assembly method that can achieve high accurate assembly even from the low level of accuracy of manufacturing parts; however, this always exists surplus parts, especially when the clearance or interference fit requirements vary in a given range. This paper presents a method in place of reducing surplus parts based on shifting the mean dimensional values and then grouping the mating parts based on their dimension tolerance and assembly characteristic. Examination case study of piston-cylinder assembly shows that by implementing this method, the percentage of surplus parts is reduced considerably (from 40.65% and 26.18% to 2.63%) and the clearance variation is minimized in comparison with the traditional ones. This method can be applied to manufacture and assemble products with high accuracy.