【作者】 丁静；

【导师】 陈柏金；

【作者基本信息】 华中科技大学 ， 材料加工工程， 2004， 硕士

【摘要】 二十世纪八十年代后期,以知识工程为核心的计算机辅助工艺规划成为主流,与此同时,钣金工件折弯工艺优化系统迅速发展。它的研究和开发工作对于打破国外对这一技术的垄断有着重要意义。本课题对钣金工件折弯工艺进行了深入研究。自主开发了一套钣金工件折弯工艺优化系统。该系统具有弯曲件的三维绘制、旋转操作、工件自动展开、弯曲工序的自动编排及加工模拟等功能。根据弯曲的工艺要求,对其工艺设计进行了深入的研究;根据板料折弯工件的形状特点,对弯曲件进行简化,抽象出弯曲件的树状数据结构,实现了折弯件图形的输入;通过对弯曲件顶点的各种变换,完成了与其相关的各种操作;对弯曲件的工艺性及其工艺参数进行了分析计算,并对现有的分析计算方法进行了总结,从而确定出加工过程中所需要的加工数据。对折弯件弯曲工艺的优化方法进行了深入研究。弯曲工序是钣金加工中最关键的工序之一,其中工序的编排是工艺规划的关键。工序编排问题可用解答树来描述,解答树的搜索空间通过采用复合弯曲、保存和重用前面的计算结果、从三维工件到二维展开图等多种方法进行优化。本系统中分两步来得到优化的弯曲方案。首先,以干涉作为回溯条件得到可行的弯曲方案;然后利用估算公式得到优化的弯曲工序。该优化结果优于其它已知优化方法所得的结果。更多还原

【Abstract】 The computer aided process planning whose hard-core is knowledge-engineering becomes the mainstream since the last of 1980’s. At the same time, the optimization of bending technology for sheet metal parts develops very quickly. The research and development of this technique are important to break up the foreign monopoly on this technique. This paper studies the optimization of bending technology for sheet metal parts and introduces an independent software. It can draw 3D bending part and rotate the part, automatically determinate the bending sequence and get unbend drawing, and can simulate manufacturing products.Study of the technical design has been done according to the characters of the pressed parts’ figure. The data structure about the figure and size of the pressed part has been abstracted based on the press parts’ figure character. Through the transform for the vertex of bending products, it can achieve all kinds of operations. For the sake of judging technology of the press parts and predigesting the press process, both the pressed parts’ technology and technical parameters have been analyzed and computed as well as the existing analysis method has been summarized. This paper studies the optimization of bending sequence. The bending sequence is one of the most critical stages in manufacturing sheet metal parts. The layout of bending sequence is an essential problem for process planning, which can be described as answer tree. By means of simultaneous bending,saving and reusing previous computation results, from 3D product to 2D unbend drawing and so on, the search space can be optimized. This system uses two-stage method to get optimized bending sequence. First this paper uses interruption as backdate condition to get feasible bending process. Then it uses estimating formulation to get optimized bending sequence. These results are superior to previously published results.更多还原