| The product reliability data is the foundation of reliability analysis and reliability growth. For a long time, most domestic machine tool companies lacked consciousness of the collecting, storing, analyzing and applying reliability data of CNC machine tools. Mass of data were saved without classification and remained idle, which could not support the implementation of the enterprise reliability engineering. Based on the national science and technology major projects "million units of CNC machine tools supporting domestic numerical control system application engineering" and "domestic high-end CNC turret series of product development and batch application demonstration", the reliability data collection in this paper was researched, and then the relevant technologies of reliability data of CNC machine tools were studied systematically. The details of paper are as follows.(1) The reliability data for CNC machine tools were classified, the characteristics and resource of the reliability data were analyzed. Then the data collection process of reliability and failure criteria were studied. On this basis, the preliminary processing technologies of reliability data were proposed. Finally, regarding the CNC lathe SK50 P as an object, the failure modes and reasons were found by analyzing and processing the failure data. Meanwhile the point estimate and interval estimation of the lathe MTBF were given.(2) The analysis technologies of little sample reliability data were studied and the information integration framework of the reliability data and information was established. In order to process the uncertain information, D-S evidence theory was researched. Then combined with the vector space, the evidence was quantified, meanwhile a simplified fusion algorithm based on evidence theory was proposed. In the end, some numerical examples were given to compare the traditional evidence fusion algorithm with simplified algorithms. Through the comparison, it can be seen that the simplified algorithm is better for solving the situation of evidence conflict, which also has a stronger engineering applicability.(3) The reliability data processing technology was used to evaluate the reliability of assembly process of CNC machine tools. Firstly, the reliability of assembly process of CNC machine was defined, then 5M1 E method was used to analyze the whole factor for the assembly process of CNC machine tools. At the same time, the simple algorithm of evidence theory was applied to evaluate the reliability of the assembly process. Finally, the assembly process of CNC lathe CK50 was taken as an example to verify the theory. |
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