Research On Reliability Modeling Technology Of Tool Magazine System

Tool magazine system is the key functional components of Machining Center, which isresponsible for quick tool changing, tool inserting. The reliability level of tool magazine systemhas the direct bearing on fast and qualified fulfilled the machining task of Machining Center,which is the key factor of Machining Center reliability. The research on reliability modelingtechnology of tool magazine system is of great significance, because it will lay a solid foundationfor understanding the failure rule of tool magazine system, reliability evaluation, reliability testand making reasonable maintenance strategy.This paper takes tool magazine to research reliability modeling technology, it relies on“High-end CNC machine tools and basic manufacturing equipment” the national science andtechnology major projects--the reliability design and testing techniques of key functionalcomponents (2010ZX04014-011).The reliability test of tool magazine is usually time truncated test which includes field test andlaboratory test. According to the characteristic of failure data of two kinds of test, this paper takesfailure truncation time, the size of sample and the proportion of failure model into account, at thesame time, the mean rank order, secondary distribution method and Bayesian theory wasintroduced to research reliability modeling of tool magazine. According to failure data ofmachining center in field test, considering the impact of truncation data of time truncated test andmultiple truncation data of tool magazine caused by failure of other machining center subsystem,the mean rand order was used to modified the order of failure data, then the reliability model ofsubsystem of machining center is built; the index of correlation was used to compare the seriessystem reliability model of by mean rank order and traditional complete machine reliability model,the result shows the rationality and validity of this method which will ensure the accuracy of fieldtest reliability model of tool magazine system. According to failure data of machining center inlaboratory test, if the sample size is enough and the repeated failure mode dominates in all failuremodes, the secondary distribution method was introduced to build the reliability model of toolmagazine system. The validity of this method could guarantee by the comparasion with firstdistribution method; if the sample size is small, the Bayesian theory was introduced to buildreliability model of tool magazine based on failure rate. The small sample reliability model inlaboratory test of tool magazine system was built by taking binomial distribution as likelihoodfunction, conjugate distribution as prior distribution, parameter estimation by moment estimation.This paper takes the characteristic of failure data in different reliability test into account tomake specific reliability modeling technology research. This research has practical significant forperfecting reliability modeling technology system, improving the accuracy and rationality ofreliability prediction and evaluation...