Research On The Feasibility Judgment And Feedback Mechanism Of Remanufacturing Retired Mechanical Parts

Remanufacturing is one of the effective ways to recycle the residual value of retired mechanical parts and realize the recycling of resources.The judgment and feedback of remanufacturing feasibility is of great significance for improving the quality of remanufacturing blanks and obtaining good comprehensive benefits of technology,economy and environment.In order to overcome the shortcomings of the existing remanufacturing feasibility evaluation methods,such as incomplete evaluation indexes and lack of feedback mechanism research on non remanufactable parts,this project carries out the remanufacturing feasibility judgment and feedback mechanism research on retired mechanical parts based on "retirement remanufacturing redesign",from the remaining fatigue life of retired mechanical parts,remanufacturing forming scheme and environmental impact The comprehensive evaluation of remanufacturability of retired mechanical parts is carried out from various angles,and the remanufacturability classification is carried out according to the evaluation results.For the retired mechanical parts that can't be remanufactured,the feedback mechanism of remanufacturability is established from the perspectives of disassembly,detection and repair.The main research contents are as follows:(1)Research on comprehensive decision model and method of product remanufacturing forming scheme based on KT method and entropy weight methodDetermining the appropriate remanufacturing scheme is the premise of remanufacturing the retired mechanical parts.Considering the expected remanufacturing effect,technical difficulty,economic cost and resource environment,the hierarchical decision-making model of product remanufacturing scheme is constructed.Taking mechanical method,coating method,laser method and surfacing method as the alternative remanufacturing forming scheme,the index weight is obtained by structure entropy weight method,the weight calculation and high sub item risk assessment are carried out by KT decision method,and the optimal remanufacturing forming scheme is obtained.Taking the forearm gear of a shearer as an example,the feasibility of the method is verified,and it is used to select the remanufacturing forming scheme of Passat B5 gearbox gear.(2)Research on the evaluation model and method of multi-dimensional hierarchical remanufacturabilityIn view of the current remanufacturability evaluation neglecting the influence of recycling,sale,policy environment,social environment and remanufacturing forming scheme on remanufacturability and the complexity and coupling caused by multiple indexes,22 influencing factors are extracted by analyzing the task flow of Remanufacturing System of retired mechanical parts,and the key efficiency index system is composed of Technology,economy and environment A multi-dimensional hierarchical remanufacturability evaluation model of retired mechanical parts is established.In order to solve the problem that the index is difficult to quantify,a method of index quantification based on fuzzy evaluation method is proposed,and the index weight is calculated by using the method of structure entropy weight,so as to take into account the subjective and objective.To solve the problem of complexity and coupling caused by multiple indexes,a new method of remanufacturability evaluation based on the method of weighted rank sum ratio is proposed.Taking the main parts of Passat B5 engine as an example,the feasibility of the method is verified and applied to evaluate the remanufactability of Passat B5 gearbox.(3)Residual life prediction method based on program load spectrumThe remanufactured blanks selected through qualitative evaluation need to be predicted for remaining life to further ensure that remanufactured products have the ability of next service cycle.In order to accelerate the fatigue test and improve the efficiency of residual fatigue life prediction,the program load spectrum acquisition method based on the rain flow counting method is studied.The mathematical model of counting results is determined by hypothesis test,and probability density function is determined by maximum likelihood estimation.On this basis,the maximum load is determined and program load spectrum is established.According to the program load spectrum,miner fatigue accumulation hypothesis and local stress-strain method are used to calculate the life.According to the relationship between the predicted life and the actual service life of gears,the remaining life of retired parts is calculated.Taking a gear as an example,the validity of the method is verified by comparing the predicted results with the fatigue test results.(4)Research on feedback mechanism of Remanufacturing Design Based on frame representationThe selected non remanufacturable parts need to be redesigned to optimize their Remanufacturability,but a large number of mechanical parts circulating in the market are not designed for the purpose of remanufacturing,resulting in many retired mechanical parts with sufficient remaining life cannot be remanufactured.In view of this phenomenon,a feedback mechanism for Remanufacturing Design of auxiliary mechanical parts is established based on the frame representation method,starting from three main factors that affect the retired mechanical parts: disassembly,cleaning and repair.The application of wechat small program framework(Mina framework),through the java script language to achieve software development.The effectiveness of the small program is verified by an example of the unsuccessful remanufacturing of the front arm gear of a Shearer in a company,and the poor Remanufacturability of the gear in the remanufacturing prediction results of Passat B5 gearbox is studied,and the reason why it can't be remanufactured is fed back.