FTA-based Importance Analysis Of Numerical Control Puncher

As the rapid development of electronic technology and hydraulic technology, numerical control punchers has become a kind of indispensable equipment for sheet metal processing enterprises with mature technology and reliable performance, but with the more and more complex structure, the impact of higher failure rate and maintenance costs of them on market competition at home and abroad is serious, therefore, the numerical control puncher fault analysis and research is imperative.1.Fault tree establishment and qualitative analysis of numerical control puncherAccording to the needs of the reliability analysis of numerical control puncher,we carried out experiments in its multiple users. At the initial stage of experiments, in order to guarantee the quality of experimental data, we first developed a data acquisition programme, standardized the subsystem and the mode of failure of numerical control puncher, drew a fault data record form,and cleared the purpose and tasks of the fault data collection. Through the experiments, we collected a number of very valuable fault data and got the first-hand material for our reliability analysis.During the experiments, we were fully aware of the structure, work patterns and practices of the numerical control punchers, communicated with the designers, heard a number of experts for their valuable advices, and had a more profound understanding of the numerical control punchers.Then we had fault tree analysis of the selected numerical control punchers.at first,we had a more in-depth analysis of the fault location, mode and reasons, established a complete machine fault tree and a number of subsystems fault tree of the numerical control punchers.Finally, we conducted a qualitative fault tree analysis of it,obtained its structure function and smallest cut sets, prepared for the further importance analysis.2.Importance analysis of numerical control puncher based on FTASuch a complex system as numerical control punchers, it is difficult to judge what system components are the key components to the system reliability, thus, in such circumstances,improving the reliability of the system must be blind. To this end,it is necessary to carry out importance analysis of the numerical control punchers to guide that improvement measures are proposed and implemented.Importance analysis of the numerical control punchers is just the quantitative fault tree analysis of them. This paper introduces the importance analysis based on fuzzy math to overcome the shortcomings of the traditional fault tree analysis in the event probability which is difficult to accurately assign. This approach reflects the fuzzy of the events'probability,at the same time,allows a certain degree of error of the probability,and combines the scene and the engineers'experience,So it has broad application prospects.The chapter will apply the importance analysis theory based on fuzzy math to study the numerical control punchers,to have importance analysis of their subsystems and the whole machine, Fully taking the uncertainties into account which caused the numerical control punchers'fault.It tested the numerical control punchers from two aspects including the fuzzy importance and crucial importance,and got the importance of the various components'basic fault models relative to the subsystems and the importance of the numerical control punchers'subsystems relative to the whole machine.3. The security and improvement measures for the numerical control punchers based on the importance analysisIn this chapter,according to the conclusions of the importance analysis of the numerical control punchers ,it give a number of security and improvement measures to improve the reliability of the numerical control punchers, recommending the guiding significance for the theorys and practical application value of the importance analysis.