Study on High Quality Machining-assembly Production System Applied a Corrective Assembly Approach : The Optimal Range of Measurement Assembly Error and the Optimal Adjustment Size

摘要

In a high quality machining-assembly production system applied a corrective assembly approach, a measurement error, which occurs in measuring a processing error of assembly part, causes an incorrect allocation of reprocessing machines and reduces a production rate of high quality assembly products. In this paper we consider a method for maximizing the production rate of assembly products which consist of two assembly parts and satisfy a predetermined assembly tolerance. In this method two optimal parameters are searched in order to maximize the production rate: one is a range of measurement assembly error which determines how to select a correct reprocessing machine and another is an adjustment size of each reprocessing machine. A relay production system is used to present the validity of the method and to investigate effects of machining accuracy, measurement accuracy and adjustment accuracy on the maximum production rate and the optimal parameters. The two main results indicate: (1) A range of measurement assembly error and an adjustment size of each reprocessing machine affect the production rate of assembly products within a predetermined assembly tolerance. (2) There exist the optimal range and the optimal adjustment size which maximize the production rate, and they vary according to a combination of machining accuracy, measurement accuracy and reprocessing accuracy in a system.