Reliability Technology Research Of Heavy CNC Machine Tools

Heavy CNC machine tools has become the basic equipment which processing large and super large parts, especially in the processing of key national projects for example defense, military, aerospace, shipbuilding, transportation and other items of products is inseparable from heavy CNC machine tools. With the advancement of national key project, the project to the requirement of increasing the quality of its products, and therefore a high level of heavy CNC machine tool for national defense project is of great significance. However, reliability has become one of the main factors affecting heavy CNC machine tool, so improve the reliability of heavy CNC machine tool has very important practical significance. In this paper, the reliability of heavy CNC machine tools were researched, the main tasks which have been done are as follows.Firstly, based on weibull distribution theory, the paper analyzes the reliability data of heavy CNC machine tool, the distribution mode of reliability life is established. The probability density function was obtained fitting the reliability data. Then makes linear correlation and hypothesis testing of the hypothesis Weibull distribution, Finally obtains the estimated value of reliability target.Secondly, using FMECA analysis method for heavy CNC machine tool malfunction was analyzed, and the heavy CNC machine tool fault database is established, the failure analysis of heavy CNC machine tool, establishment of a heavy CNC machine tool fault database. Finding out failure patterns, failure mode and failure reason of the machine,finding out failure mode and the cause of the key parts, To solve these failure mode and the reason for heavy duty CNC machine tools improvement opinions are put forward.Thirdly, the reliability allocation of heavy CNC machine tools was studied. The reliability of heavy-duty CNC machine tools was distributed by the means of fuzzy analytic hierarchy process (FAHP), which overcomes the disadvantages of traditional distribution method. At first, a weight value of fuzzy complementary matrix was established between the two factors, the weight matrix was also obtained by the integrated use of this, secondly, the fuzzy matrix of CNC every party in view of the factors influencing the reliability allocation was established. Finally based on the requirements of the project goals for heavy nc machine tool reliability allocation.Finally, In order to solve the problem of fault date of Heavy CNC machine is little,can not be used to assess the reliability evaluation method of traditional, using the Bayes method under the condition of Weibull on the reliability of heavy CNC machine tool reliability evaluation. Using the method of Bootstrap to get a large of prior information and fitting out the prior distribution. Get MTBF posteriori distribution through on the reliability index of MTBF posteriori inference. The data in test of prototype will heavy CNC machine tool into the posteriori distribution of MTBF and get a more accurate assessment of the results.