线材折弯设备设计及线材折弯回弹特性研究

发布时间：2018-11-16 16:00

【摘要】：随着装备制造业的发展,对金属线材弯曲件的形状复杂程度、产品精度及加工速度要求越来越高,传统的手工或半自动弯曲方式很难满足需求,发展全自动线材折弯设备十分必要。且在卸载过程中,线材不可避免的发生回弹,更是严重影响产品成形质量。因此,研究各工艺参数和材料参数对线材回弹现象的影响,尽可能减小回弹,提高成形质量,具有重要的现实意义。本文针对线材折弯设备及线材折弯回弹特性进行深入研究,具体内容如下:首先,根据对线材折弯设备的需求分析,进行线材折弯设备方案设计,并针对储料模块、送料校直模块、上料模块以及联动折弯模块四个主要功能模块逐一进行设计,最终实现线材折弯设备的总体结构设计,在结构方面实现了更好的柔性和更高的集成化程度,并实现了连续加工,提高了加工效率。其次,对线材折弯回弹现象进行研究,采用解析法和数值法分别对线材进行两种弯曲角度的分析计算,并将回弹角度的理论计算结果与数值模拟结果进行对比分析,具有良好的一致性,证明数学模型的正确性及可靠性。另外,对线材卸载回弹过程中线材内部残余应力进行了分析。再次,运用正交试验法,以线材的回弹角度及回弹半径作为指标,研究相对弯曲半径、弯曲角度、相对弯曲力矩、弯曲力臂长度、硬化指数及强度系数六个影响因素对线材折弯回弹的影响,得到线材对回弹影响因素的灵敏度排序。并基于矩阵分析法,得到线材折弯最佳参数组合,并验证最佳参数组合的正确性。最后,基于Visual Basic 6.0编程软件开发一款线材折弯回弹预测系统,用户通过选择或设置与实际工况相符的参数,提交后系统自动调用ABAQUS有限元分析软件进行数值模拟,直接显示所预测的回弹角度并输出后处理文件,为回弹问题的解决提供了新途径,具有传统方法无法比拟的效率优势。
[Abstract]:With the development of equipment manufacturing industry, the requirements of shape complexity, product precision and processing speed of metal wire bending parts become more and more high. Traditional manual or semi-automatic bending methods are difficult to meet the demand. It is necessary to develop automatic wire bending equipment. In the process of unloading, the springback of wire is inevitable, which seriously affects the forming quality of the product. Therefore, it is of great practical significance to study the effect of various process parameters and material parameters on the springback of wire rod, to minimize the springback and improve the forming quality as much as possible. In this paper, the bending characteristics of wire bending equipment and wire bending are studied. The specific contents are as follows: firstly, according to the demand analysis of wire bending equipment, the project design of wire bending equipment is carried out, and the material storage module is designed. The four main function modules of feeding straightening module, feeding module and linkage bending module are designed one by one. Finally, the overall structure design of wire bending equipment is realized, which realizes better flexibility and higher integration degree in structure. Continuous machining is realized and processing efficiency is improved. Secondly, the springback phenomenon of wire bending is studied. The analytical method and numerical method are used to analyze and calculate the two kinds of bending angles, and the theoretical results of springback angle are compared with the results of numerical simulation. It has good consistency and proves the correctness and reliability of the mathematical model. In addition, the internal residual stress of wire during unloading springback is analyzed. Thirdly, the relative bending radius, bending angle, relative bending moment, length of bending force arm are studied by using orthogonal test method, with the springback angle and springback radius of wire rod as the index, the relative bending radius, the bending angle, the relative bending moment and the bending force arm length are studied. The influence of six factors, hardening index and strength coefficient, on the springback of wire is obtained, and the order of sensitivity of wire to springback is obtained. Based on matrix analysis, the best parameter combination of wire bending is obtained, and the correctness of the best parameter combination is verified. Finally, based on the programming software of Visual Basic 6.0, a springback prediction system of wire bending is developed. The user chooses or sets the parameters consistent with the actual working conditions, and the system automatically calls the ABAQUS finite element analysis software to carry on the numerical simulation after submitting. Direct display of the predicted springback angle and output of post-processing files provide a new approach to the resolution of the springback problem and have an incomparable efficiency advantage compared with the traditional method.
【学位授予单位】：江苏科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG305

【参考文献】