Research On Remanufacturing Design Quality Control Method For The Used Machine Tools

As a new mode of machine tools manufacturing based on the recycling of waste resources,machine tools remanufacturing can not only save resources and protect the environment effectively,but also become a new economic growth point.But machine tools remanufacturing in China is developing slowly at present.It is lack of systematic and in-depth research on remanufacturing design quality control methods.For the great part,it leads to unstable quality,less competitiveness and less social recognition for remanufactured machine tools.As the competition in the machine tools industry is getting fiercer and fiercer,remanufacturing design for the used machine tools must be carried out in order to reach or even exceed performance and quality of the new ones.So the remanufacturing design quality control method for the used machine tools based on robustness was proposed,which is significant to guarantee the quality of remanufactured machine tools,improve the market competitiveness and promote the development of machine tools remanufacturing industry.With the support of the National Natural Science Foundation Project(51305279)and Shenyang Jingxin Remanufacturing Co.,Ltd,the whole remanufacturing process of used machine tools was analyzed in depth.Especially the research on remanufacturing design quality control method was done.The main contents are as follows:(1)As for the unstable remanufacturing quality,the mapping and transformation relationships of quality characteristics in different stages were revealed and the whole process quality model of used machine tools remanufacturing was constructed.And a remanufacturing design quality control framework based on robustness was built,providing the theoretical basis for the quality control research.(2)As for the recycling quality uncertainty of used parts,the method of extensive and comprehensive evaluation and classification was put forward based on multiple index and interval numbers.It can not only effectively evaluate the remanufactable quality attribute,but also distinguish the degree of remanufacturability,thus to provide scientific basis for the remanufacturing process decision-making.(3)As for the lower market competitiveness of remanufactured machine tools,the programming model based QFD and nonlinear fuzzy regression was set up for redesign quality parameters.It can fully consider discrete values and minimize fuzzy outputs of correlations,between customer demands and remanufacturing design quality parameters and self-correlations among these parameters.Then overall quality planning for remanufactured machine tool was done in order to improve customer satisfaction.(4)As for the conflicts between original restricts of the used machine tool and increasing customer requirements,the method of remanufacturing design conflict resolution based on TRIZ and Extenics was proposed.The technology conflict matrix for remanufacturing design was constructed,then some inventive principles were obtained.The matter-element of conflict structure was transformed to expansion diverging tree.And the optimal remanufacturing design scheme was determined through extensive goodness decision.(5)Aimed at the difficult problem of used parts remanufacturing process decision-making with multiple objectives,multiple attributes and uncertainty,the method of remanufacturing process decision-making based on Extenics and grey correlation analysis was put forward.The decision matrix was constructed with grey interval numbers,fully considering the correlations among decision indexes.A decision model based on the optimal degree of extension grey correlation was established and the optimal remanufacturing process scheme was determined.Remanufacturing design for an used CAK6136 machine tool was applied to verify the method proposed.Firstly,the remanufacturable quality attribute of its guiderails was evaluated.On this basis,overall quality parameters planning of remanufacturing design was carried out,fully considering customer satisfaction.Then the remanufacturing design conflict was resolved for its spindle box and the optimal remanufacturing design scheme was determined.Finally,the process decision-making was made for its guiderails and the optimal remanufacturing process scheme was determined.So the proposed method can better guarantee the efficiency and quality of remanufacturing design process,improve the comprehensive performance and customer satisfaction of remanufactured machine tools,and the remanufacturing benefits are remarkable.