可制造性评价中的尺寸分析和评价

Dimensions Analysis and Evaluation Study in Manufacturability Evaluation

通过建立子结构类型及其各定位关系的描述规则，可以自动得到零件上不能在制造中直接保证的设计尺寸．对设计尺寸进行必要的转换，使得零件上所有的尺寸都能直接保证．这样就可以根据加工设备的能力，判断零件的设计尺寸是否满足制造约束．

The dimensions, just as the structures of the parts designed, should be checked whether they meet the manufacture constraints so as to guarantee the maufacturability of the parts. The dimensions are the attributes of features and can be judged directly through the capabilities of the equipment that manufacture the features. The dimensions that constrains the relations among features of a part are contained in the structures larger that features—substructures. Not all dimensions that constrains the relations among features can be guaranteed directly by manufacture equipment. Some of them may be guaranteed indirectly through other dimensions related too. Substructures that may contain such indirectly guaranteed dimensions are extracted from part information according to the corresponding descriptions of such kind of substructures, so that the dimensions on the part which can not be guaranteed directly can be identified, and used in dimensions tree transformation. In dimensions tree transformation, the dimensions tree, which represents the related dimensions in a certain direction, are transformed to a new dimensions tree which contains no indirectly guaranteed dimensions. Dimensions represented by such new dimensions tree can be judged directly through capabilities of the corresponding manufacture equipment.