五轴龙门加工中心可靠性分析与评价

发布时间：2018-08-16 15:03

【摘要】：提升国产高档加工中心及其关键功能部件的可靠性水平,是顺应数控设备高精、高效、高速、柔性和复合加工发展趋势的首要任务。本文在江苏省科技支撑计划重点项目——"大型五轴高速精密龙门加工中心绿色设计技术与应用研究"项目的资助下,以五轴龙门加工中心为研究对象,通过综合运用可靠性技术体系,有效评估新研制的加工中心的可靠性水平。论文主要研究内容如下:1、在产品设计阶段,根据收集的相似成熟产品的故障数据信息,通过FMEA方法对故障部位、故障模式和故障原因进行分析,找到该类产品的薄弱部位并提出相应的改进措施,提高设计产品的可靠性。2、以相似成熟产品服役阶段的故障间隔时间数据为基础,采用分布拟合检验方法建立故障时间模型,确定该批加工中心的故障数据服从威布尔分布,得到可靠度的分布规律。通过研究各次故障时间的可靠性分布规律,建立基于各次故障时间的可靠性模型,来描述各次故障时间之间的关系,实现对加工中心可靠性水平的评估。3、在样机试制阶段,综合考虑加工中心的实际工况,通过正交试验设计切削力试验,得到相对全面的载荷谱。以载荷谱的幅值均值为单一协变量建立WPHM可靠性评估模型。利用ADAMS软件结合试验载荷建立整机动力学仿真模型,获得关键零部件滚珠丝杠的载荷谱,进而对其进行静强度可靠性分析和疲劳寿命分析,验证了所选滚珠丝杠符合可靠性要求。4、以灰色理论为基础,建立基于故障间隔时间的灰色GM(1,1)预测模型,来实现对未来故障发生时间的预测,以便提早做好防护工作,提高加工中心运行过程中的可靠性水平。5、利用Matlab GUI语言根据可靠性评价和分析工作的要求开发可靠性信息管理系统,实现故障数据的管理、统计分析、可靠性评价和预测等功能。
[Abstract]:To improve the reliability level of domestic high-grade machining center and its key functional components is the primary task to conform to the development trend of CNC equipment with high precision, high efficiency, high speed, flexibility and compound machining. In this paper, we take the five-axis gantry machining center as the research object, funded by the key project of Jiangsu Science and Technology support Program, "Green Design Technology and Application Research of Large-scale Five-axis Precision Gantry Machining Center". The reliability level of the newly developed machining center is evaluated effectively through the comprehensive application of the reliability technology system. The main contents of this paper are as follows: in the stage of product design, according to the fault data of similar mature products, the fault location, fault mode and fault cause are analyzed by FMEA method. The weak parts of this kind of products are found and the corresponding improvement measures are put forward to improve the reliability of the design products. Based on the fault interval time data of similar mature products in service stage, the fault time model is established by using the distributed fitting test method. The fault data distribution of the batch machining center is determined from Weibull distribution, and the distribution rule of reliability is obtained. By studying the reliability distribution law of each failure time, the reliability model based on each failure time is established to describe the relationship between each failure time, and to realize the evaluation of reliability level of machining center. Considering the actual working conditions of machining center, a relatively comprehensive load spectrum is obtained by orthogonal design of cutting force test. The reliability evaluation model of WPHM is established with the amplitude mean of load spectrum as a single covariable. The dynamic simulation model of the whole machine is established by using the ADAMS software combined with the test load, and the load spectrum of the ball screw of the key parts is obtained, and then the static strength reliability analysis and fatigue life analysis of the ball screw are carried out. It is verified that the selected ball screw meets the requirements of reliability. Based on the grey theory, a grey GM (1 / 1) prediction model based on the fault interval time is established to predict the future fault occurrence time, so as to do the protection work well ahead of time. The reliability level of machining center is improved. The reliability information management system is developed by using Matlab GUI language according to the requirements of reliability evaluation and analysis, and the fault data management and statistical analysis are realized. Reliability evaluation and prediction functions.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG659

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