Research On Reliability Analysis And Control Technology Of Ak31CNC Turret

As the cell technology carrier of NC machine, the key functional components’reliability level directly affects entire machine tool’s level, however the functionalcomponents of domestic high-grade CNC machine tool are unable to get rid of thedependence on imported components, and there is a larger gap between its reliabilitylevel and the foreign advanced level, so the study of its reliability is extremely urgent.As the most critical functional unit of CNC lathe, CNC turret can guarantee completemany or all of the machining process in one clamping, cut down the auxiliary time ofprocessing, reduce the error caused by the multiple installations, however it’s any tinyfault’s happening will result in the break off or stop of the machine work, then reducethe machining efficiency and precision of machine tool, so it is necessary to do thein-depth study of the CNC turret reliability. The current domestic research on thereliability of CNC turret is focused on the reliability test and evaluation, but the detailedCNC turret reliability analysis and control research is less. So according to the majornational S&T program, with the AK31CNC turret of Yantai Universal Machine ToolAccessory Group as the study object, we have the in-depth reliability analysis andcontrol technology research to supply the good reference value for the CNC turretreliability’s promoting.The main research content of this article is as follows:①On the basis of structure and working principle of CNC turret, we get thecorresponding relation between function level and structure level, the mission reliabilitymodel through the system definition. Have the statistical analysis of the past CNCturret’s maintenance records, receiving the failure modes, causes and fault positionsstatistical results of CNC turret products. Have the FMEA to CNC turret, getting thefailure mode and the reasons of the function parts, and put forward the correspondingimprovement and compensation measures. Analysis the fuzzy perniciousness level ofCNC turret by the method of fuzzy RPN, and the risk prioritization of functional parts isreceived, providing the pointed reference for the reliability’s promoting.②Have the fault tree analysis on CNC turret, according the past FMEA situation,we select the common failure modes as the top event, and find the deep reasons of theeach failure modes. For the fault tree models, we find out the minimum cut set throughthe qualitative analysis, and through the quantitative analysis get the probability interval of top events, the important degrees of bottom events by the probability and fuzzynumber theory, and this analysis makes the results more objective and accurate, andfinally we can find the weak link of CNC turret product reliability.③Have the study of reliability control technology on the manufacturing processof AK31CNC turret. The entry inspection process of purchased components and thereliability evaluation system of components suppliers are given, having a good controlfor the incoming reliability. The related process ability of key parts is analyzed, and thecontrol measures are given. Last, the reliability-driven assembly technique for AK31CNC turret is made, have the good practical significance for the promoting of assemblereliability.