【作者】 李琳；

【导师】 刘晓平；

【作者基本信息】 合肥工业大学 ， 计算机软件与理论， 2002， 硕士

【摘要】 冷冲模是机械生产行业的重要工艺设备，而模具的设计是一个很繁杂的检索和绘图过程，采取计算机辅助技术可以加速这一过程，产生良好的经济效益。本文首先以建立面向具体领域的三维专用冷冲模CAD系统为出发点，结合特征建模技术，分析总结了冷冲模的结构特点，给出了冷冲模的特征分类和相应的数据结构。采用模板记录特征设计树，灵活体现了设计思想和过程。针对合作的企业并没有完全实现CAD\CAM一体化，在设计、装配、审定时都要用到工程图，同时二维图样对于工程师是必不可少的思想交流媒介和资料积累，所以本文着重研究了由三维零件模型自动生成符合工程习惯二维图样的过程和方法。首先对各种剖视图的自动产生进行了分析，提出了剖切特征的概念，在此基础上讨论基于优先度和基于图遍历的两种通过寻找关键剖切特征产生最佳剖切路径算法，并给出剖切的实现过程；随后阐述如何使三维模型二维化时更符合工程标准；最后描述了零件图和装配图的自动产生过程及相应的算法实现，探讨尺寸自动标注时带来的反馈模板修改和整个设计的全相关性。 本文的主要贡献是： 1)在总结各种系统中工程剖视图生成不足的基础上，为了更好地统一剖切思想，提出了归一化剖切特征的概念。 2)为三维CAD软件进行剖切智能引导提供了有效的方法和算法，从而使工程图的生成进一步自动化。 3)总结一种基于特征的工程图自动生成方法，并在冷冲模零件图和复杂装配图上验证了其有效性。更多还原

【Abstract】 Press tools are important technical equipment in the field of mechanical engineering. In dies design, drawing and searching are time-consuming, but computer-aided technique can accelerate these processes to obtain good economic benefit. The feature category and data structure for each are provided by using feature-modeling technique, after summarizing structure feature, which is based on 3D construction of press tool CAD system in special field. Developing the template of recording feature design tree leads to flexibility and convenience of design. The integration of CAD/CAM hasn’t realized absolutely in some enterprises and the 2D drawing has taken and will take an important role in intercommunion and data accumulation, so the method of auto-transform from 3D part model to 2D drawing is the primary studying object to meet with the requirement of engineering. Firstly, a new concept of slice feature is defined after analyzing the automatic generation of many kinds of cutaway views. On the basis of it, two proposed algorithms, based on priority and graph travel respectively, are capable of choosing the key slice features for the generation of the slice path. The slice method on the given graphics platform is described subsequently. Secondly, the steps transformed from 3D to 2D are shown and make it possible to meet engineering requirements more. Finally the methods dealing with the auto-generation of the part drawings and assembly drawings are offered, including some relative algorithms. Dimension auto-placement and its relativity during the process of whole design are also discussed in this section. The main contributions of the dissertation are:1) A new concept of slice feature is proposed, on the basis of the shortage of engineering drawings in some CAD systems, which can unify the slice idea.2) The effective algorithms about the generation of cutaway drawings are provided to the guidance of intelligent slice in 3D CAD software, which can make the generation automatically and rapidly.3) This thesis summarizes a auto-generation method of engineering drawings which is based on features. And the efficiency and reliability are proved by complicated part drawings and assembly drawings of the press tool.更多还原