UTILIZING CAD/CAM SYSTEMS TO DESIGN PATTERN EQUIPMENT MACHINING USING CNC MACHINE TOOLS ON THE BASE OF THE UNIGRAPHICS SYSTEM

摘要

Taking a core box as an example, the problems of computer-aided design (CAD) and computer aided manufacturing (CAM) of foundry tooling using the UNIGRAPHICS system have been presented. Delivered by the customer three-dimensional geometry of the product is the base of rapid making of the pattern equipment. In the environment of CAD of the UNIGRAPHICS system a foundry pattern is formed taking into account, among others, casting contraction and machining allowances. After a logical operation of removing the solid of a casting from the solid of a pattern one can obtain the solid of the inside of the casting, which - after adding the core prints - is changed into a core. In the successive operation of removing a core from the monolithic block with the dimensions consistent with the outer outline of a core box, one can obtain a core box, and in effect its suitable part. Next, by means of CAM modules of the UNIGRAPHICS system, the strategy of the core box machining using a numerically controlled milling machine is formed. The system renders it possible to choose any milling cutter you like and to programme an adequate sequence of machining, comprising in this case rough, profile and finishing milling. After generating the tool path, it is sent to the machine tool, on which the process of automatic milling of the cavity of a given part of a core box takes place. The application of CAD and CAM enables a considerable shortening of the production preparation time as well as fulfilling the increasing quality demands. The use of this type of software is one of the elements which makes the facing of challenges standing before a foundry of today possible.