Anselm Schüle

Feature precedence graphs as an approach for the forming operations planning of integral sheet metal parts

Feature precedence graphs are well-known models to describe products for process planning purposes. In this paper, we propose a process planning approach for integral sheet metal parts with higher order bifurcations. Those products are produced in a continuous manufacturing process by applying the new manufacturing technologies of linear flow splitting and linear bend splitting in combination with roll forming. We introduce new form-features, operation features, and forming features to represent integral sheet metal parts of higher order bifurcations from a design and manufacturing perspective on different levels of detail. The resulting feature precedence graphs are acyclic directed graphs. Thus, topological sorting algorithms can be applied to generate feasible sequences in the model.

A Simultaneous Engineering Approach for Free Form Bifurcated Sheet Metal Products

In this paper a simultaneous engineering approach is introduced to cope with the complex and elaborative engineering design process for bifurcated sheet metal products. The design process comprises product design, sheet blank design, and tool design. Free form surfaces derived from mathematical optimization processes are the starting point for product, tool, and sheet blank design. Part design is strongly connected and references to the underlying free form surface. For the 3D-CAD models a modeling concept is introduced where free form surfaces are referenced from an external source. A workflow to manage the design process and to deal with possible changes and iterations during product development is also developed and presented.

Automatic 3D Documentation Method for Manufacturing Processes

Product documentation plays an important role in product creation. Many parts of the documentation are used for manufacturing, assembly and quality assurance processes. Until today the leading document for manufacturing processes is the engineering drawing. With more complex product designs the clarity of the drawings decreases. Modern technologies enable the transition to a paperless manufacturing documentation without the need for expensive licenses. 3D-PDF technology offers a way to provide manufacturers with 3D-CAD models containing the appropriate product manufacturing information.In this paper a generative document that provides only the essential information for certain manufacturing steps is presented. 3D-PDF technology is used to present the results to the machinist. The recommended documentation provides two different views: the input and output status of a product at a specific manufacturing station. Those views are created automatically from the ERP database containing manufacturing knowledge of the product. The presented models are supplemented with general information, e.g. material, designer, general tolerances. The limitation on necessary information for only one manufacturing step at a time increases the comprehensibility of the product documentation and thus accelerates the manufacturing process and improves product quality.Copyright