Research On The Development Of Sheet Metal Parts Based On 2D Drawing Feature

It is a basic step to determine the blank of a sheet metal part for analyzing the deformation and deciding the stamping process of the part. The blank as an important parameter, it will directly impact the quality of the formed sheet metal part. Since 3D CAD software is expensive, 2D CAD software, such as AutoCAD, is still widely used in medium and small scale corporation to design stamping dies. For the sheet metal parts are represented by 2D drawing, the blank is manually determined by a designer. If a sheet metal part is complex, the calculating is very tedious and time-consuming. In order to simplify the calculating and raise its efficiency, in this thesis, the methodology of developing the sheet metal parts represented in 2D drawing is researched.According to the deformation characteristics of sheet metal part, the form features of the sheet metal part are classified into main features and add-on features. Main features mainly include bending features and drawing features, add-on features mainly include hole-features and partial forming features.Based on the characteristics of 2D representation of features, a method of feature extraction which integrates interactive recognition with automatic recognition is put forward. After extraction from 2D drawing, features can then be developed respectively according to their types and their development rules. The final blank shape of the sheet metal part can be gotten by translating and rotating all the developed features to combine them together.Base on the methods discussed above, the CAD system for calculating the blank shapes of sheet metal parts has been implemented by using ObjectARX under AutoCAD2000 platform. The system can help user easily and effectively expand a sheet metal part which is represented by 2D drawing.