The Research Of An Aided Programming System Based On A NC Machine Center

In modern society, NC machine center has been an important device for mechanical manufacture, its appliance has been more and more widely accepted. But how to get the numerical control program quickly and accurately is really an urgent problem to be tackled. In this paper, an auto programming software is developed based on DXF files, this software mainly aims at a machine center-FEELER 800A which uses the NC system of SINUMERIK 810D from SIEMENS.DXF(Drawing Exchange Files)files are also called graphic exchange files, they translate the information about graphics into ASCII files according to the prescribed regulations. It has already been treated as the industry standard of CAD. In this paper, by analyzing the structures and contents of the main sections of DXF files, the graphic informations which are useful during NC machining are selected, then the auto programming software can automatically generate NC programmes according to these informations.Concerned that there are technical requirements on NC maching, the information picked from the DXF files can not be used directly to NC programming, they must be processed before making the final numerical control codes which can be used by the machine center.The sequence of the geometry objects that appear in DXF is depended on the sequence of the drawing, and so is the directly picking sequence, this sequence has nothing to do with the machining sequence. So, in this paper, the geometry objects picked from the DXF files are firstly resorted based on start-point method. The measurement of the directly picked geometry objects are determined by the users who made it, and generally the geometry measurement data are based on the label of the geometry objects, in this paper, the geometry measurement data arerenewed by the label information of the graphics.The graphic information picked and processed from the DXF files are different from the route which the tool actually goes about, because the positions and measurements picked are based on the Paper-Coordinate, it may be different from the Part-Coordinate which the tool should goes in. Thus, before auto programming, there must be a change from Paper-Coordinate to Part-Coordinate.According to the graphics information data, the numerical control programs which aim at the SINUMERIK 810D system are automatically made based on NC codes standards. And this system covers the machine types of mill and drill, it can also integrate dispersed points to B-curved lines which can be used as tool position.In the actual manufacturing with NC machine, in order to check whether the parts design and the cutting route are right or not, generally it is tested by examing how the tool and work plane will move with the input NC programme and without an actual part. Once the movement does not match the prescribed process, there must be a change to the design graphics and the NC programme, and then test again, until the tested one matches the requirements. This inevitably leads to the waste of manpower and time, so it is necessary to make a computer simulation to realize the fastness and preciseness of the movement and path of the machine. In this paper, OpenGL is used to simulate the NC machine process.Finally, based on all these work, FEELER 800A NC auto programming software is developed in the circumstance of Visual C++ 6.0, and it runs quite well after test on the machine center, thus it can be concluded that it has quite practical usability.