VMC650Five-axis (Vertical) Machining Center Hydraulic System’s Reliability Evaluation

Machining center is the efficient and automated machine tools used for processing the complex shaped workpieces, is the typical electromechanical products combined the modern information science and mechanical technology. The type of processing center in this paper mainly aimed at mold industry, used for processing every kinds of mold. However, the reliability of the current level of domestic processing centers is significantly lower compared with the situation abroad, seriously affecting the competitiveness of the domestic processing center.Hydraulic system plays an important role in modern production equipment and control system, and plays an irreplaceable role in power transmission and control. Due to the complexity, kinds of fault type, the hydraulic system has a problem of poor reliability compared with other products. Processing center hydraulic system failure often leads to the system’s fault, resulting in significant economic losses.After briefly introducing the main content and the meaning of the research, in this paper we begin the hydraulic system’s reliability evaluation, find out the weak link, and then design a hydraulic cylinder-one of the weak link of the system with the reliability optimization.First, this paper analyses the principle and function of the hydraulic system to understand the system work flow. On the basis of the system reliability modeling theory, we build a reliability block diagram model. Based on the components reliability data collected, we get the system reliability data and other performance data from the result of simulation, pointed out weaknesses and develop a maintenance order by using of the reliability analysis software Blocksim and engineering software Matlab’s software package Simulink. In addition, this paper also studies the system fault tree. After the establishment of the system fault tree analysis of the hydraulic system, we obtain the deep reasons of the hydraulic system failure.This indicates the key points of system maintenance.Secondly, based on the analysis of the system, we carried out the hydraulic cylinder, one of the most system weak links, in the reliability optimization design. Its reliability plays an important role in the reliability of the whole system.In this paper, the design method. Of the hydraulic cylinder is on the basis of the traditional design, which combined reliability design with optimization design principle. By using of the engineering mathematical software MATLAB and using it’s Simulink package for dynamic performance simulation, we get the optimal solution quickly. Ultimately we improve the reliability of the hydraulic cylinder parts. Comparing the design and simulation results before and after in this paper this method also showed the superiority of the reliability optimization design.