复杂曲面模具钢高速铣削振动特性研究

发布时间：2018-07-16 11:59

【摘要】：复杂曲面模具是重要的工艺装备,直接影响到产品的更新换代能力,在现代制造业中占有举足轻重的作用；其加工制造能力则是国家制造水平的综合体现,具有巨大的经济和社会效益。机床的运行总伴随着振动,机床的振动会导致被加工工件的形状精度和表面精度降低,刀具寿命和生产率下降。本文将主要围绕复杂曲面模具钢高速铣削振动特性分析的相关问题,从切削机理出发,通过理论和试验分析,全面系统地对高速切削中铣削力及其切削振动问题做深入研究。1.铣削曲面的加工过程是一个复杂的加工过程,涉及到许多参数,彼此之间还相互影响,其中切削力是切削过程中一个重要参数,是研究“刀具-工件”系统、建立模型和动力学分析的基础。本文在建立的铣削力模型的基础上,通过试验对切削力系数进行识别,并对模型的精确度进行验证。此外,分析了切削速度、每转进给量和切削深度对铣削力系数的影响规律。2.考虑铣削过程的复杂性,刀具振动是影响加工工件表面质量的一个重要因素。因此借助ANSYS有限元分析软件,对实际切削加工中的刀具和工件有限元结构模型进行振动模态仿真分析,然后与试验模态分析结果进行对比验证。经过比较分析,本文通过试验模态测得的固有频率与有限元结构模态分析得到的模态振型相符,为铣削振动特性研究做好准备。3.针对高速切削系统结构和受力都比较复杂的特点,对空转条件下和高速切削过程中主轴和工件的振动进行检测并进行对比分析。通过单因素试验定量地描述并系统地分析了塑料模具钢NAK80在不同切削用量条件下主轴和工件的振动变化规律,探讨了引起切削振动的内在原因。这些对切削振动的研究,对揭示切削振动机理,检测和分析切削振动,从而采取有效措施减少切削振动、提高加工表面质量奠定了基础。
[Abstract]:The complex curved die is an important process equipment, which directly affects the upgrading ability of products and plays an important role in the modern manufacturing industry, and its processing and manufacturing ability is a comprehensive embodiment of the national manufacturing level. It has great economic and social benefits. The movement of machine tools is always accompanied by vibration. The vibration of machine tools will reduce the shape accuracy and surface precision of the workpiece being machined, and the tool life and productivity will decrease. This paper will focus on the problems related to the analysis of the vibration characteristics of high-speed milling of complex curved die steel. Based on the cutting mechanism and through theoretical and experimental analysis, the milling force and its vibration in high speed cutting will be studied thoroughly and systematically in this paper. The machining process of milling curved surface is a complicated machining process, which involves many parameters and also affects each other. Among them, cutting force is an important parameter in the cutting process and is used to study the "Cutter-workpiece" system. The foundation of model and dynamics analysis is established. On the basis of the milling force model established in this paper, the cutting force coefficient is identified by experiments, and the accuracy of the model is verified. In addition, the influence of cutting speed, feed rate per rotation and cutting depth on milling force coefficient is analyzed. Considering the complexity of milling process, tool vibration is an important factor affecting the surface quality of workpiece. Therefore, the finite element model of cutting tool and workpiece is simulated and analyzed by ANSYS finite element analysis software, and the results are compared with the experimental modal analysis results. Through comparison and analysis, the natural frequencies measured by the experimental modal are consistent with the modal modes obtained by the finite element structural modal analysis, which is prepared for the study of milling vibration characteristics. In view of the complex structure and force of high speed cutting system, the vibration of spindle and workpiece under the condition of idling and during high speed cutting is detected and compared. The vibration changes of the spindle and workpiece of plastic die steel NAK80 under different cutting parameters were described and systematically analyzed by single factor test, and the internal causes of cutting vibration were discussed. These researches on cutting vibration lay a foundation for revealing the mechanism of cutting vibration, detecting and analyzing cutting vibration, and taking effective measures to reduce cutting vibration and improve the quality of machined surface.
【学位授予单位】：沈阳理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG54

【参考文献】