【正文】 感謝所有關(guān)心我、支持我、幫助我的朋友！最后，要感謝家人的支持、關(guān)懷和鼓勵(lì)！ 林慶潮 2006年6月外文翻譯1：Fault Mode and Effect Analysis for VMC Vertical CNC Machining CentersXianglei Chi, Xucheng Li (Beijing Machinery and Electricity Institute)Yazhou Jia, Jie Yu and Yi Dai (Jilin University)Abstract: FMEA method is used to analyze the faults of vertical machining center. We should find out the ratios of the fault positions and the fault modes, the weak links and latent weakness of the should feed the analysis back to the departments responsible for the designing, manufacturing and assembling. Some measures are adopted and the reliability levels of Machining Center are enhanced clearly.Key Words: Machining Center, FMEA, faults analysis, information collecting 1. Introduction Machining Center is a typical united product which bines modern information science with mechanical technology. With the development of science and technology and the continuous quotation from new technology, the mechanical and electronic products are getting more plicated and more plicated, the using conditions of the products are more and more, so the demands for the products’ reliability are getting higher and higher[1].Fault Mode and Effect Analysis (FMEA) is an important part of the reliability and is also one of the important method and measure of reliability enhancing and designing[2]. In order to enhance the reliability of the machining center, the weak links and latent weaknesses according to the analysis of the products’ construction and the fault modes must be found and the analyses must be feed back to the departments responsible for the designing, manufacturing, assembling, supplying and service after selling. Thus the products’ reliability can be enhanced.According to the fault data collected on the spots of VMC750 CNC Machining Center, FMEA method is used to analyze the faults. We should find out the fault positions and the ratios of the fault modes and fault causes. We should find out the fault modes which greatly affect the reliability of the whole machine. We should further analysis the fault modes and fault causes which frequently arise in the subsystems and parts. We should seek the trends of the enhancement and design of the reliability. Through the analyses of fault modes and effects, we should learn the weak links of VMC CNC Machining Center and provide based for removing the products’ faults.2. Fault modes of Machining Center The objective fault data should be firstly gained for carrying out FMEA analysis. So the enterprise should set up Failure Reporting, Analysis and Corrective Action Systems. The fault data are all collected from the users’ fault reports and the manufacture’s maintenance records. These data basically reflect the fault status of the machining center. When we collect the reliability information, the codes of the fault modes and subsystems (fault positions) must be defined at first so as to set up fault information data base[3]. In this paper, fault positions table (see table 1) and fault modes table ( see table 2) of machining center and defined.Table 1 Subsystems of Machining Center (fault positions)CodeNameCodeNameSSpindle boxXFeed system of X axisYFeed system of Y axisZFeed system of Z axisMTool magazineHHydraulic systemNCCNC systemDManipulatorPLCPLC systemWCooling systemLLubricating systemEPower supplyQProtective equipmentVElectrical systemTable 2 Fault Modes of Machining CenterFault typeFault modeCodeFault modeCode01damatged01spare parts damaged010103wire and cable broken010302elements damaged010204wir and cable short circuits010402loosed01tighen parts loose020103wire and electrical parts poor contacted020302protighten parts loosed020203blocked up or leaked out01liqued, gas, oil leaked out030102liquid, gas, oil blocked up030204dislocated01tolerance of moving parts dislocated040103spindle dislocated040302flows of hydraulic parts dislocated040204tool magazine dislocated040405moving01spindle and tool magazine collided050104turning and moving exceeded050402moving parts blocked up050205returning zero inaccurate050503turning and moving parts illlocated050306status01temperature raised060104the foundation parts vibrated060402too loud noisy060205abnornal noise060503large strike of moving parts060307technology01geometric precision over standard070103working precision over standard070302position precision over standard070208nonmechanical faults01warning by mistakes080107parts function lost080702control of gas and liquid out order080208system parameters wrong080803mechanical and electronic mutual lock mechanism out of order080309ground wire illlinked080904sensor parts out of order080410the external power unstable081005motor out of order080511virus infect system081106parts parameters wrong08063. Analysis of Fault Positions is the fault frequency and fault block chart of machining center. The codes of abscissa see Table 1.From , we can see:(1) In the parts and subsystems of VMC750 CNC machining centers, the faults ratios of CNC system and spindle box occupy of a large part and both are %. The faults of CNC system major in CRTs and the percent is 9 which is almost half of the system fault. On the other hand, the fault of CNC system major in the bought and joint parts. In order to decrease the faults ratio of CNC system, CRT must be changed first and selected the optimization ones. Assembling links of spindle box must be adjusted.(2) The third faults ratio is Electrical system. The electrical system here excludes CNC system and includes the power supply