基于DXF 轴类零件特征的NC 车削自动编程图形输入系统的研究

在计算机辅助NC 车削自动编程系统中，既快速又准确输入零件图形信息，是实现数控编程自动化的首要环节。基于DXF 轴类零件图形的特征信息，通过深入分析DXF 文件结构，构造基于轴类零件的数据结构(包含几何信息和工艺信息)，采用图素求交算法提取与输入各图素的特征信息，客户可在屏幕上点选特征图素并输入对应的工艺信息，然后利用动态绑定技术将处理后的数据储存到数据库中。不同的特征图素将产生不同类型的表，可通过打开数据库的方式输入零件图形，最终输出系统所需的数据结构。结果表明：开发的程序系统可以快速准确地输入DXF 轴类零件图形，生成的数据结构满足刀位点计算要求，能够为虚拟NC 加工仿真提供技术支持。

Research on NC Lathe Turning Automatic Programming Graphic Input System Based on DXF Shaft Parts Feature

In computer aided numerical control (NC) lathe turning automatic programming system,fast and accurate parts graphic input is the primary link of realizing CNC automatic programming.Based on the feature of DXF shaft parts graphic information, through in-depth analysis of DXF filestructure, data structure was set up based on the data of shaft parts (including geometry informationand process information). Graphic element intersection algorithm was adopted to extract and put inthe feature information of each figure, and users could click on the feature of graphic element on thescreen and enter the corresponding process information, and then data processed will be stored in thedatabase by using dynamic binding technology. Different feature of the graphic element will producedifferent types of table. It can input part graphics through the way of opening the database, and finallyit outputs data structure required by the system. Results show that the developed application systemcan rapidly and accurately input DXF shaft parts graphics, and data structure generated meets thedemands of calculating tool locus, which is able to provide technical supports for virtual NCmachining simulation.