The Optimal Tolerance Design Based On The Sustainability Of The Product

Tolerance is a bridge between the manufacturing and the design of the mechanic product. To a great degree, the rationality of the determined tolerance decides the performance, reliability, service life and other key performance characteristics of the product. The purpose of the tolerance design is to get high quality product with low cost. With the pollution of the environment, the shortage of the resource, and the advent of "human-oriented" theory, the manufacturing industry as the main economy’s foundation, is forced to gradually change the production model from the open loop system of traditional manufacturing mode to the strategy of sustainable development considering the economic, the environment, and the society at the same time.Tolerance throughout the whole life cycle of the product has close relationship with the economic, environment, society impact of the product. Now, the optimization design of the tolerance mainly focuses on the minimization of the summation of the manufacturing cost and the quality loss cost. Some related researches based on the manufacturing environment, manufacturing procedure, robustness and so on. However, few researches about the tolerance design take the sustainable development of the product into consideration. The key of the optimal tolerance design facing the sustainability lies in the consideration of the economic, environment, and society impact of the product among its life cycle in the process of tolerance design. This research conforms to the need of the era development and has practical significance.According to the existing technology of the tolerance design and combining the core of the sustainable development, this paper proposes the optimal tolerance design facing the sustainability of the product. The main works of this paper are as follows:1) Review the history and research status of the computer aided tolerancing, the design based on the sustainability of the product, and the research status of the optimal tolerance design facing the sustainability of the product, and have a brief introduction of the concept and connotation of the sustainable development;2) Analyze the relationship between the tolerance and the sustainable influencing factors of the product, and put forward the relation model between the sustainability of the product and the tolerance decision-making;3) Combining the result of qualitative analysis between the sustainability of the product and the tolerance, have a quantitative analysis to the sustainable impact of the stages of manufacturing, usage and disposal in sequence;4) According to the result of the quantitative analysis, and combining proposed cost-tolerance functions and the existing related researches, propose the mathematic model between the tolerance and the sustainable impact cost of the product;5) Propose the objective function of optimal tolerance design facing the sustainability of the product, and get the optimal tolerance distribution outcomes; analyze and verify the proposed optimal tolerance method through the tolerance design of the milling head of a CNC milling machine.