基于圆角特征简化的工序三维几何建模方法

摘要

三维实体模型是CAX集成研究中的基础，圆角特征广泛存在于零件设计模型中，为提高此类零件工序三维几何建模的准确性，提出一种基于圆角特征简化的工序几何建模方法。通过分析工序三维几何建模过程中对圆角特征几何元素的提取过程，提出构建圆角特征线段，以便准确获取三维模型上的加工特征边界；利用加工特征边界和拉伸、旋转和扫掠3种常用的几何造型方式，建立加工体积特征；通过上一道工序的三维模型与加工体积特征作布尔差运算，得到本工序的三维几何模型。最后以某零件的工序三维几何建模过程为例，采用3种方法进行工序几何建模，通过对结果的分析对比，验证了文中方法的优越性。%3D solid model is the basis of CAX integration. Fillet features widely exist in the design model of parts. In order to build in-process model forthe parts with fillet features accurately, a method was proposed, which is based on fillet feature simplification. By analyzing the extraction of geometric elements of fillet features in the process of in-process modeling, we create the fillet feature line segments to get the accurate processing feature border of 3D model, and establish machined volume features using the method of stretching, sweep and rotation. By applying boolean difference operation to themachined volume features and the former in-process model, we can get new in-process model.An in-process modeling process of a part was provided to verify the validity of the proposed method.