Integration of design and manufacture of complex geometries through solid and surface modeling techniques

This paper presents the concepts of integrating a solids and surface modeler database with a manufacturing postprocessor in the production of complex shapes and geometries encountered in high technology manufacturing. The postprocessor translates information between a standard IGES file and the solid modeler to be fed to a 5 axis CNC machine. This process is demonstrated through an example which generates the mold cavities of an injection molding toll. IGES surface entities are created individually for each face of the solid model and the postprocessor creates a CNC program based on ruled surfaces corresponding to the IGES surface information. A second method is presented in the transfer of information between a surface modeler, a design database and the postprocessor. The design database provides information for blade shapes which are altered periodically. The surface modeler builds the complete impeller shape based on cross sectional geometries, overall design dimensions and number of blades on a given impeller. The postprocessor transfers the geometrical data from the surface modeler into a 5 axis CNC machine to manufacture the impeller blades. Blades are exclusively defined by ruled surfaces, so, the tool design and dimensions are critical to the success of the machining operation.