Research On Process Drawing Generation Method And System For Shaft Parts

Computer Aided Process Planning (CAPP) is the bridge of CAD&CAM and the key technique of CIMS. CAPP has become the research focus because of its importance in the manufacture field. Process drawing generation system is one of important part in CAPP system, which would be helpful for improvement of efficiency, and of great purport on practicality of CAPP system. Nowadays, Methods of process drawing generation is difficult to solve problem about dynamic model edition, and the low automation efficiency in the process drawing production, as one of the main bottlenecks in CAPP.Presently, the process drawing is produced in reverse order, which can make full use of the information inside the part drawing, and is much easier and more applicable than the one obtained in normal order. But the technology of process drawing production is in urgent need of improvement in terms of efficiency. In this paper, shaft parts, which are the relatively simple rotational parts, will be discussed as a researched object. More specifically, by utilizing the AutoLISP provided by AutoCAD2005and Microsoft Visual Basic, we present a new approach to better the production efficiency of the process drawing of shaft parts. The main conclusions were as follows:(1) Parts information coding storage. According to the structural characteristics of shaft parts, with the parts classification and coding method for the foundation, developed a suitable system of2D part drawing primitives, named coding rules. Then by the man-machine interactive way of obtaining characteristic parameters, in drawing parametric feature, and store it in the table structure, implementation of shaft parts information storage, and provide the basis for drawing processing sketch.(2) Automatic generation of process drawing. Process drawing based on the features of the graphic element modification method, according to the process drawing generation process, feature modification follow different principle, the traditional machining technology documents reclassification, putted forward a new classification method of process information. According to the method presented in this paper generate data files. Then the computer read the data file, generated the process independence, and save. Finally in the system provided a visual interface, from the block pool tagging symbols, realization of symbols fast marking.(3) Linear size chain of technology computer aided solution. By means of technological dimension chain tracking chart method to express, processed dimension information into a plurality of data matrix; then the size information matrix inputted into computer, through the computer resulted the dimension chain trace, established of dimension chain matrix; then check the design tolerance and process margin by computer; finally completed the calculation process dimension.