Research On Product Layer Life Matching Method For Predecisional Remanufacturing

Remanufacturing engineering is an important measure to implement the strategy of "circular economy" in China.It is an advanced form of resource reuse and was listed as a national strategic emerging industry.At present,the problems of "early" and "delayed" remanufacturing of key parts in predecisional remanufacturing lead to the low efficiency and the unsuccessful implementation of predecisional remanufacturing.Aiming at this problem,this paper focus on the design of predecisional remanufacturing at product level,and proposed a product layer life matching method for predecisional remanufacturing.The selection method of predecisional remanufacturing timing for key parts,the construction and solution of life matching function,and the design method and process of product layer life matching were mainly studied,and the method was applied and validated with diesel engine as an example.Firstly,the idea of life matching was elaborated,and the concrete connotation of structure layer and part layer life matching was given.And the idea of life matching was introduced into predecisional remanufacturing design,the concept of product layer life matching was put forward.Secondly,from the point of view of service performance of key parts,an predecisional remanufacturing timing selection method for key parts based on damage threshold was proposed.Taking diesel engine as an example,the evolution of fatigue damage and wear during crankshaft service was analyzed.Taking the fatigue strength redundancy factor and the minimum oil film thickness of bearing lubrication as evaluation indexes,the critical damage threshold of fatigue damage and wear of remanufacturing was determined.On this basis,the process of selecting the timing of predecisional remanufacturing of crankshaft based on fatigue and wear was given.And taken a single cylinder diesel engine as an example,the predecisional remanufacturing timing of crankshaft,connecting rod and piston was determined respectively.Thirdly,based on the idea of predecisional remanufacturing timing control,the concept of life matching function was proposed,and the solution of zero point of life matching function was transformed into objective optimization problem,and differential evolution algorithm was used to solve the problem.Based on this,the product layer life matching method and design process based on life matching function were given.Finally,taken the single cylinder diesel engine as an example,the application and validation of product layer life matching method were carried out.The results show thatthe equivalent matching of predecisional remanufacturing timing of diesel engine and key parts was achieved after product layer life matching design,which effectively reduces the number of disassemblies,remanufacturing and reassemblies during the whole life cycle of diesel engine,and improves the efficiency and benefit of predecisional remanufacturing for diesel engine.