Method And Key Technology Of Assembly Quality Control For Remanufactured Engine

As the final element of remanufacturing,reassembly is of vital importance in improving the utilization of remanufactured parts as well as keeping the quality of remanufactured product.The existing of remanufactured part or reused part with exceed dimension and the instability during reassembly process have resulting in various production problems,such as the waste of production materials,the low qualification rate of remanufactured product,the higher cost of remanufacturing production.Taking remanufactured engine as the research object,this paper puts forward a quality control method for remanufactured engine,and researches the critical technology of the method proposed.First,this paper introduces the typical reassembly methods and describes the technological process of remanufactured engine,and the connotation of uncertainties during reassembly process is defined.On this basis,the structure of the assembly quality system for remanufactured engine is proposed,and the technical route of the assembly quality control method for remanufactured engine is elaborated.And the connotation of the assembly quality control method is briefly described from three aspects,they are the classification management method of reassembled parts for remanufactured engine,the optimal model of assembly parts set for remanufactured engine and the assembly quality dynamic monitoring model for remanufactured engine,respectively.Next,the optimal model of assembly parts set for remanufactured engine is further researched.This paper proposes a classification method for parts' mating dimension.In order to ascertain the parts' dimension grade of follow up assembly workstation,taking parts' dimension grade as the state vector,the one-step transition probability matrix of the reassembly Markov Chain is defined,and the classification mating model for reassemble parts based on the Markov Chain is constructed.Based on the researches above,optimal model of assembly parts set for remanufactured engine is established to provide optimal solution scheme for reassembled parts selection,to make the maximum utilization of remanufactured parts with lower cost and to reduce the production cost of remanufacturing enterprise.Taking certain assembly process of remanufactured crankshaft,for example,the feasibility and effectiveness of the model is verified.Then,this paper explores in depth the assembly quality dynamic monitoring model for remanufactured engine.After analyzing the influence factors of assembly process for remanufactured engine,taking the assembly operation input and component input as the input vector,the assembly status of remanufactured engine as the state vector,the assembly precision of remanufactured engine as the output,the state space model of assembly process for remanufactured engine is constructed,and the operation compensation function is built.The assembly quality dynamic monitoring model and the flow diagram for reassembly process are put forward.And the effectiveness of the model is verified with the application example of the remanufactured crankshaft's assembly process.Finally,on the basis of the researches above,the assembly quality control prototype system of remanufactured engine is preliminary developed on analyzing the functional requirement of the quality control platform,which provides technical assistance for the assembly quality control of remanufactured engine.