Analysis and Design Bulb Shield Progressive Drawing by FEM Simulation 2007-01-1674

Bulb shields are important components in automobile headlamps and are primarily manufactured by progressive draw dies. Among progressive forming, multiple station progressive draw dies are the most formidable and thus among the most difficult of all progressive dies. Draw processes of a dome shape bulb shield are modeled and analyzed by FEM code DYNAFORM v5.2. Simulation prediction matches well with the measurement from the prototype test. A surface distortion problem is also identified and a solution is obtained through punch nose radius effect on stress distribution analysis. The tooling based on the suggested design has been manufactured and is running successfully in a Cleveland based production plant. Since the forming problems can be visually identified before physical tooling is manufactured, compared with the traditional development, the tooling tryout time has been shortened from several weeks to several days.