Research On Selective Assembly Method Optimization For Construction Machinery Remanufacturing

Under the background of establishing resource-saving and environment-friendly society, remanufacturing will bring enormous economic and social benefits. However, remanufactured products, often regarded as second-hand products with inferior quality and unstable performance, are misunderstood by the public, which constrains the development of remanufacturing. Currently, the research on improving the quality of remanufactured products mainly focuses on improving the processing quality of remanufactured parts, while improving the accuracy of assembly is ignored. What’s worse, blindly increasing the processing quality of parts will lead to a substantial increase in the cost of remanufacturing. Therefore, based on the features of assembly in the remanufacturing, a selective assembly method in remanufacturing is proposed, which aims at improving the remanufactured product quality in the absence of additional cost and increasing the success rate of assembly and utilization ratio of remanufacturing parts. The research contents mainly include:Firstly, by analyzing the basic process and the uncertainties of construction machinery remanufacturing, three main factors that may influence the assembly quality are concluded, and the error propagation mechanism of the uncertainties along the assembly dimension chain is revealed. In order to alleviate the effect that mixing reused parts, remanufactured parts and new parts make on the assembly quality by transmitting and accumulating the errors, a selective assembly method of remanufacturing is proposed. And the relevant theories are briefly introduced.Secondly, on the purpose of improving the accuracy of assembly, a mathematical model based on multivariate quality loss function and dimension chain constraint is built. At the same time, the assembly success rate and remanufacturing resource utilization rate are selected as selective assembly quality evaluation indexes based on the features that the remanufactured parts should be utilized preferentially and the remaining unmatched parts should be reduced under the condition of satisfying the accuracy of assembly. Thus, a comprehensive selective assembly model targeted at remanufacturing assembly accuracy and rem anufacturing resource utilization can be formed.Finally, as the nature of optimal selective assembly in remanufacturing is a combinatorial optimization problem, the ant colony algorithm is applied into remanufacturing selective assembly based on the analysis of the characteristics and basic principles of the ant colony algorithm. Then, according to the features of optimal selection problem in remanufacturing, a structural graph model is established, where the parts to be assembled are abstracted as nodes. And the path length, pheromone update strategy and heuristic function of the ant colony algorithm are redefined and optimized, which contribute to forming a comprehensive target in selective assembly of ant colony algorithm. Also, the steps of an alternati ve method in arithmetic implementation and the parameters affecting arithmetic performance are presented. By applying remanufacturing selective assembly method into assembling crank and connecting rod mechanism, the method is proved to be effective in guaranteeing the accuracy of assembly. Meanwhile, the matching rate of different parts and utilization rate of remanufacturing resource are obviously improved.