Research On Transform From 3D Part Model To Engineering Drawings

Press tools are important technical equipment in the field of mechanical engineering. In dies design, drawing and searching are time-consuming, but computer-aided technique can accelerate these processes to obtain good economic benefit. The feature category and data structure for each are provided by using feature-modeling technique, after summarizing structure feature, which is based on 3D construction of press tool CAD system in special field. Developing the template of recording feature design tree leads to flexibility and convenience of design. The integration of CAD/CAM hasn't realized absolutely in some enterprises and the 2D drawing has taken and will take an important role in intercommunion and data accumulation, so the method of auto-transform from 3D part model to 2D drawing is the primary studying object to meet with the requirement of engineering. Firstly, a new concept of slice feature is defined after analyzing the automatic generation of many kinds of cutaway views. On the basis of it, two proposed algorithms, based on priority and graph travel respectively, are capable of choosing the key slice features for the generation of the slice path. The slice method on the given graphics platform is described subsequently. Secondly, the steps transformed from 3D to 2D are shown and make it possible to meet engineering requirements more. Finally the methods dealing with the auto-generation of the part drawings and assembly drawings are offered, including some relative algorithms. Dimension auto-placement and its relativity during the process of whole design are also discussed in this section. The main contributions of the dissertation are:1) A new concept of slice feature is proposed, on the basis of the shortage of engineering drawings in some CAD systems, which can unify the slice idea.2) The effective algorithms about the generation of cutaway drawings are provided to the guidance of intelligent slice in 3D CAD software, which can make the generation automatically and rapidly.3) This thesis summarizes a auto-generation method of engineering drawings which is based on features. And the efficiency and reliability are proved by complicated part drawings and assembly drawings of the press tool.