细长轴尺寸误差有限元分析与补偿研究

发布时间：2018-02-11 18:08

本文关键词： 细长轴尺寸精度 DEFORM ANSYS 数控车削让刀量补偿　出处：《西华大学》2014年硕士论文　论文类型：学位论文

【摘要】：轴类零件在机械工业领域占有相当大的比重，是一类不可缺少的重要零件,它主要用于支撑回转零件以及传递转矩或运动。轴类零件被大量用于众多领域中，而这些轴之中存在一种非常特殊的轴，其长径比大于20，把它定义为细长轴；由于它的长径比大、刚性不足以及加工过程中振动等因素影响,在切削加工时极容易因弯曲而发生形变，因而极不容易满足设计精度要求。伴随高科技技术的不断发展与进步，对零件的设计和制造精度提出了更加严格的要求,针对传统加工方法已难以加工出符合设计精度要求的细长轴，因此寻找新的方法和途径是未来提高细长轴加工精度的研究重点。提高细长轴的加工精度，主要在于提高细长轴的加工尺寸精度。本文采用理论分析—仿真分析—实验验证的逻辑思维方式。首先结合国内外参考文献对引起细长轴尺寸误差的众多因素进行了分析，归纳出引起细长轴加工尺寸误差的主要因素包括：径向力引起的弯曲变形、工件和刀具的热变形；然后分别建立径向力作用下的弯曲变形模型、工件和刀具的热变形模型，并推导出了一个与细长轴切削参数、材质、刀具热膨胀系数等相关的理论让刀量预测公式;接着,通过DEFORM软件测出了切削力的分力-径向力Fp的大小，为接下的ANSYS仿真提供了仿真参数,同时DEFORM仿真结果表明刀具切削加工中刀具温升T随时间不断增大，在切削初期温升T急剧上升并趋于热平衡时的温升值；使用ANSYS软件对细长轴车削加工进行了静力学分析,并将径向力作用下的理论让刀量值和仿真值进行了对比分析，结果表明二者具有高度的一致性，并利用MATLAB软件对理论让刀量公式进行了预修正优化处理，求得了更为精确的让刀量补偿预测公式。最后论文介绍了一种误差补偿方法，并利用该补偿法将优化后的精确让刀量补偿公式用于数控车削加工，实验结果表明，运用该优化让刀量补偿公式能显著提高细长轴的加工尺寸精度,达到了本次研究的目的，同时为以后细长轴尺寸精度的进一步研究提供了重要的参考依据。
[Abstract]:Shaft parts occupy a large proportion in the field of mechanical industry. They are a kind of indispensable important parts. They are mainly used to support rotary parts and transfer torque or motion. Shaft parts are widely used in many fields. And there is a very special shaft in these shafts, with a aspect ratio greater than 20, which is defined as a slender shaft, because of its large aspect ratio, the lack of rigidity, and the vibration during processing, and so on. It is easy to deform when cutting because of bending, so it is very difficult to meet the requirement of design precision. With the development and progress of high technology, the design and manufacture precision of parts is required more strictly. In view of the fact that the traditional machining methods are difficult to produce slender shafts that meet the requirements of design accuracy, finding new methods and approaches is the focus of research on improving machining accuracy of slender shafts in the future. Improve the machining accuracy of slender shaft, The main purpose of this paper is to improve the machining accuracy of the slender shaft. In this paper, the logical thinking mode of theoretical analysis, simulation analysis and experimental verification is adopted. Firstly, many factors causing the dimension error of the slender shaft are analyzed in combination with references at home and abroad. The main factors causing machining dimension error of slender axis are summarized as follows: bending deformation caused by radial force, thermal deformation of workpiece and cutting tool, and then the bending deformation model under radial force and the thermal deformation model of workpiece and cutter are established respectively. A theoretical prediction formula related to the cutting parameters, material and thermal expansion coefficient of the cutting tool is derived, and the magnitude of the cutting force, the radial force F p, is measured by DEFORM software. At the same time, the DEFORM simulation results show that the temperature rise T of the tool increases with time, and the temperature rise of the cutting tool increases sharply at the beginning of the cutting and tends to the heat balance. The static analysis of slender shaft turning is carried out by using ANSYS software, and the theoretical value of radial force is compared with the simulation value. The results show that they are highly consistent. By using MATLAB software, the precorrection and optimization of the theoretical tool size formula are carried out, and a more accurate prediction formula for the compensation of the tool size is obtained. Finally, an error compensation method is introduced, and the optimized accurate compensation formula is used in NC turning. The experimental results show that, The precision of machining dimension of slender shaft can be improved significantly by using the optimized compensation formula, and the purpose of this study is achieved. At the same time, it provides an important reference basis for further research on dimension accuracy of slender shaft in the future.
【学位授予单位】：西华大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TH133.2

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