CAD-Methodik zur Produktivitätssteigerung in der Prozesskette Konstruktion-Fertigung
Für die wissenschaftliche und methodische Unterstützung während meiner gesamten Zeit als wissenschaftliche Mitarbeiter und Doktorand am Lehrstuhl für Rechnereinsatz in der Konstruktion gilt mein Dank meinem Doktorvater Prof. Dr.-Ing. Dipl.-Math. Peter Köhler sowie allen Lehrstuhlkollegen, vor allem jedoch Dr.‐Ing. Alexander Martha, Thivakar Manoharan M. Sc., Phil Hungenberg M. Sc. und René Andrae M. Sc.Danksagung
It is indisputable that a design engineer is responsible for the requirement-driven functional and geometrical design of new products and that through this responsibility, has a significant impact on the associated quality and manufacturing costs. The complexity of the design solutions often prohibits an adequate assessment of the production costs and can make it difficult to consider alternative manufacturing methods. The manufacturing costs normally emerge only once the product is phased into production. In order to allow the design engineer to better fulfill this responsibility for product costs, this dissertation considers the technical productivity (expressed with the terms effectivity and efficiency) of the process chain between the design engineering and production departments. There are answers to the questions formulated: What can be done to achieve an improvement in the current process-chain between the design engineering and production departments? In answering this question, CAD methods will be introduced which allow the inclusion of production knowledge into the earliest possible stages of the design and development process. Considering selected problem fields in the drilling, turning and milling processes, solutions for creating geometry through machining methods and for analyzing the producibility of 3D CAD models will be presented. Through the implementation of the methods and the development of a special machining-focused environment in the 3D CAD system, the design engineer will be given the ability to align the product modeling process with design guidelines and project-specific manufacturing and economic constraints. By using special methods of knowledge-based design engineering (KBE) and adapted web technologies (Webservice), the geometric information which is bundled in a production-focused form feature will be supplemented with additional technological parameters, such as tools, tool parameters, tool paths and necessary manufacturing operations (e.g. roughing and finishing). For more complex geometrical features, surface-based modeling methods for the design of three-dimensional and production compliant tool-movement envelopes will be provided. These increased-value, production-oriented features are the basis for the cost-estimation in the design phase and for the coupling of the CAD and CAM environments. As a result, the manufacturing-relevant data and information will be extracted by the CAM environment so that the production operations for each step can be determined in a simple manner. This approach results in a complete chain between the design engineering and production departments and can improve the quality of the CAD-CAM information exchange.