应用过渡特征简化的工序几何建模方法

摘要

To build In-Process model rapidly,an In-Process modeling method was proposed by combining blend feature simplification with boundary extraction of machining feature.Boundary of the machining feature was obtained by simplifying blend features in machining feature,and it was selected to build processing volume characteristic by rotation,sweep,or stretching.Boolean subtraction between the former In-Process model and the processing volume characteristics was operated to obtain In-Process model.Edge blends and vertex blends were distinguish,and the situation of support surface lose was analyzed when blend features simplified.A process of typical shaft parts turning In-Process modeling was provided to analyze the In-Process model's dimension change rule which was built by different boundary of machining feature.The effectiveness of proposed method was verified by examples.%为了快速建立工序几何模型,提出一种将过渡特征简化和加工特征边界提取相结合的工序几何模型建立方法.首先对加工特征中的过渡特征进行简化,获得加工特征边界；然后选择加工特征边界,利用旋转、扫掠或拉伸方法建立加工体积特征；用前一道工序的几何模型与该加工体积特征做布尔差运算,求得本工序的工序几何模型.在简化过渡特征时区分边过渡和点过渡,并综合考虑支持面丢失等情况.以典型轴类零件的车削加工工序几何建模为例,分析了选择不同加工特征边界建立的工序几何模型的尺寸变化规律,验证了该方法的有效性.