Topology Optimization of Valve Lever Taking into Account Possible Manufacturing Processes of Prototype

Topology optimization often results in a complex 3 dimensional geometry that can only be achieved through considerable effort. If the smoothed optimization result has undercuts or even hollow cavities, a reaction with metallic materials is possible, for example by laser melting. An interpretation of the optimization results is essential for the use of cost-effective production techniques. The final component geometry must not be too different from the actual optimization result whilst taking into account the economic factors of production.

Due to manufacturing restrictions such as maintaining a minimum / maximum wall thickness or ejection direction, the manufacturability of these products increases greatly. This simplified geometry is often still so complex that it can only be done by removing material layer by layer using 5-axis milling or electrical discharge machining. In addition to being time consuming, such production techniques also result in high costs. Manufacturing processes such as casting and forging can also be used, even when the geometry involved is relatively complex. When only a small number of items are to be produced, these production techniques don’t come into consideration due to the high tooling costs and the limitations on the material.

Lightweight construction already plays an important role in the preliminary development of valve levers, particularly in high-speed piston engines. Because of short switching times and the resulting high acceleration forces and stresses, load bearing and weight-optimized geometry is already required for the prototype in order to keep the high dynamic forces acting on the valve train to a minimum.

Due to the small numbers of prototypes, the often limited possibilities of the prototype workshop have to be taken into account during optimization. By varying the manufacturing restrictions the possible manufacturing processes can be made visible. Based on these results, appropriate manufacturing processes can be chosen.

The final optimization is then responsible for selecting the restrictions considered necessary to choose which manufacturing processes can be implemented.

This presentation shows how a clever combination of different optimization results can make an apparently complex initial set of results less complex, and at the same time lead to a faster and more cost-effective manufacturing process. This approach is often limited in terms of model building due to the available manufacturing processes without making it too different from the actual results of optimization.

The Author

belCAT Ingenieurbüro Stuttgart plans, develops and designs products for many different industries. Founded in 2006, the engineering services provider is based in Stuttgart and covers entire development projects. belCAT‘s customers are well known companies from the automotive and consumer goods industries.