基于草图尺寸继承的标注模板定制方法

A dimensioning template customization method based on inheritance of sketch dimensions

为保证尺寸标注的正确性和布局的合理性,避免当模型尺寸发生变化后,繁琐地重新调整布局,提出一种基于草图尺寸继承的标注模板定制方法。针对基于草图的回转(拉伸)类零件,自动提取草图对象参数信息,根据标注类型选取不同参数信息作为尺寸放置点的参考基准,并添加适当调整量,确定草图中合理的尺寸放置点。再根据齐次坐标变换原理,将草图尺寸放置点映射得到工程图尺寸放置点。最后在制图环境下完成相应的尺寸标注。将草图尺寸继承到工程图上,实现了标注模板的快速定制,保证了当模型尺寸变化时,工程图尺寸的值和布局能自动更新。以某航空发动机风扇盘的尺寸标注为例,通过对UG软件的二次开发实现该算法。实例结果表明该方法能较有效地实现尺寸标注的智能化。

In order to ensure the correctness of dimensions and rationality of layout, and avoid readjusting the layout cumbersomely when the model size was changed, a template customization method based on inheritance of sketch was put forward. The parame- ters of sketch objects could be extracted from the revolved or extruded feature based on sketch. According to the dimension type, select different parameters as reference datum for placement, and add appropriate adjustment to ensure the reasonable placement in sketch. Then map the placement to engineering drawings by means of the principle of homogeneous coordinate transformation, and complete the corresponding dimensioning in drafting, Inheriting sketch dimensions to engineering drawings quickly customized the template and ensured that the value and layout of dimensions could be updated automatically when the model size was changed. Take the dimensioning of an aero-engine fan disk for example. The algorithm could be realized through the secondary de- velopment of UG software. The result showed that the method can effectively implement the dimensioning intelligentization.