基于GB/T 24734的三维自动标注

摘要

结合制造企业对三维CAD零件尺寸自动标注的需求,探讨了以国标GB/T 24734为依据的在CAD系统中实现三维尺寸自动标注的技术.设计并实现了三维自动标注的算法,详细阐述了其相关的技术.该算法涉及零件基准识别、特征简化、表面分组、垂向投影标注以及零件特征还原等一系列技术.其中,特征简化和还原主要涉及特征和草图级别的倒角、圆角及阵列操作.为了便于尺寸的布局和识别,采用了表面分组和垂向投影标注的方法来对零件进行分解.以CAXA实体设计软件为平台,实现了上述算法,开发了自动标注模块,并验证了算法的可行性.%To meet the requirements of manufacturing enterprises,the automatic dimensioning of 3D model in CAD system was investigated based on the national standard GB/T 24734.The algorithms of automatic dimensioning of 3D model were proposed,and the strategies of datum recognition,features simplification,surfaces grouping,vertical projection and features restoration were described in detail.Currently,the processes of features simplification and restoration mainly deal with the blending,chamfering and array operations in both feature and cross-section levels.To make the layout and identification of dimensions much easier,the methods of surface grouping and vertical projection were applied to discompose the part.All the algorithms presented were realized and a module of automatic dimensioning was developed based on CAXA Solid.Case study shows that the strategies presented are feasible.