Based On FMEA And Important Analysis Of CNC Lathe Designed To Improve Reliability

1. The purpose of the study and its significanceThe production, possession and use of the field for CNC machine tool has become a measure of a country's level of industrial development in one of the important symbols。In recent years ,CNC machine tools are faster development in the production and application fields in China,but,there are still large gaps between the industrialized countries and China. Improve the reliability of CNC machine tools has become a important key of the current machine manufacturing enterprises for their own survival and development. While users often give more attention on function and the maintenance of the advanced nature than the features and advanced machine, that is, reliability. The reliability of CNC machine tool have become an important standard to purchase machines for users, reliability of China's CNC machine tool product facing severe challenges.In this paper, Jilin province science fund project"for the life cycle of computer-aided NC machine tool usability research of key technologies"on the CNC lathe reliability were studied. FMEA analysis and important analysis were used for CNC lathe based on the failure data which has been collected, and provide a theoretical basis for formulated neasures of reliability growth technology,as well as evaluated the reliability of the machine, design for the specified direction ,and then improve the reliability of CNC lathe effectively.2.The content of the study and resultsFMEA analysis of CNC lathe with the fault data. in the first before establish a fault location, pattern and the cause of the malfunction table. In this paper,the pattern classification has been improved on the basis of the original fault mode table. CNC lathe will be what happened to the failure mode of a specific subsystems, and so on can be more effective analysis of CNC lathe reliability, which is to improve the design.In this paper, through FMEA analysis of CNC lathe, we can see that the fault CNC lathe multiple site electrical systems, turret Turret, clamping annex, the three different parts of the fault by the occurrence of total failure of 2 / 3 also more. The most frequent failure mode of CNC Lathe is the damaged devices, the damaged parts, transfer or transfer is not in place, lines and cable connections bad, and other moving parts, which accounted for five failure mode of the overall failure mode Nearly 80 percent more. The multiple reasons of CNC lathe for the respective percentages of fault are the device damaged, and parts damaged, open misplacement, and so on, they all cause of the malfunction of the 2 / 3. CNC lathe against the most vulnerable to the faulty parts (electrical systems, turret Turret, clamping annex) again FMEA analysis to identify the impact of these key subsystem failure mode and the cause of the malfunction. We can obtained some of the CNC lathe reliability analysis by the data through FMEA analysis, laying a foundation for reliability design.FMEA analysis is a important way of the analysis of the reliability of CNC lathe, although a simple FMEA analysis can also compare CNC lathes and thoughtful analysis of the reliability of indicators, but I think that is not comprehensive enough and accurate, and can be impact too great by the people,so the reliability of the methods are questionable, which is the reliability of CNC lathe works is a defect.In this paper a more comprehensive understanding accurate summary of important equipment method was supported to address the problem.Important analysis is a method that analysis of the fault position , failure mode and the cause of the malfunction on the basis of FMEA and FMECA (Hazard degrees),the and further CNC lathee. Although some subsystem fault are too much but have less interferences with the normal operation of the affected less than some subsystems do not happen often but once there will be the normal operation of CNC lathe impact is fatal. Therefore this paper use the CNC lathe important grade analysis, which considered not only from the failure of a single occurrence, but also the impact of this factor, more objective and accurate reflection of each subsystem on the importance of the CNC lathe. In this paper, an important analysis will be divided into: Necessity, fault, impact, the impact that these are important factors of the reliability of CNC lathe. Through the important analysis of CNC lathe that the various subsystems important difference from high to low levels are electrical systems, the main drive system, feed systems, turret Turret, hydraulic system, clamping annex, bed tail planes, and the protection system.Reliability design is an important componentto improving the reliability of CNC lathe. In this paper, on the basis of CNC lathe FMEA analysis and the analysis of important degrees, combining the the results research of institute predecessors made specific improvements designed to enhance the level of reliability of CNC lathe.