Papers by Author: Simon Opel

Abstract: Manufacturing of functional sheet metal products with integrated gear teeth by form-ing can be realised with the application of bulk forming operations on sheet metals. Due to the desired part geometry simultaneous 2D and 3D stress and strain states occur during the forming operations. The main challenges of sheet-bulk metal form-ing are high resulting forming forces and the demand on a specific control of the material flow. In addition, there is a distinctive interaction between blank thickness and resulting part quality. To meet these challenges at high material efficiency, the application of tailored blanks with a defined sheet thickness distribution is a promising way. The process adapted semi-finished used in the presented work are formed by a flexible rolling process. First of all, the forming concept for the realization of geared sheet metal components using flexible rolled tailored blanks is presented. Afterwards, the developed rolling machine to produce rotational symmetric tailored blanks is shown, as well as the fundamental process influences during rolling. Based on that, the development of suitable process strategies to produce tailored blanks with a thickened sheet edge is presented. The further processing of those tailored blanks for the realization of external geared sheet metal components will show the advantages compared to the application of conventional sheet metals of constant sheet thickness. Therefore the concept of a combined deep drawing and ironing process is presented. The results show, that on the one hand the material efficiency is increased in comparison to the usage of conventional sheets of the same maximum thickness. On the other hand, the application of flexible rolled tailored blanks improves the accuracy of shape of the gear teeth. Both approaches prove that the application of flexible rolled is an appropriate procedure to enhance the limits of using conventional sheet metals within sheet-bulk metal forming.

Abstract: Manufacturing of functional sheet metal products by forming can be realised with the application of conventional bulk forming operations on sheet metals. The challenges of those sheet bulk metal forming processes are high resulting forming forces and the demand on a specific control of material flow. To meet these challenges well-directed thinning of blanks as well as accumulations of material to form functional elements is employed. Due to local loads, simultaneous 2D and 3D stress and strain states occur. Process adapted semi-finished products, containing a defined sheet thickness characteristic, are formed in the presented work by the technologies upsetting and orbital forming. Orbital forming is an incremental bulk forming operation to decrease the forming zone extension and consequently the required process force. Afterwards a process combination of deep drawing and upsetting in order to manufacture a cup-shaped workpiece with external gearing is presented. The results of this integrated single-stage forming process are discussed and subsequently the potential to enhance the process limits is shown by using process adapted semi-finished products.

Abstract: The demand on closely-tolerated and complex functional components in the automotive sector, like e.g. synchronizer rings, leads to the development of a new process-class named “sheet-bulk metal forming”. Within this technology bulk metal forming operations are applied on sheet metals. In the following two novel approaches considering machines and tools for sheet-bulk metal forming are presented. The first approach aims on a technology based on rolling, which is suitable for mass production. The second one is an incremental forming solution for low batch production. Both machine concepts allow the application of different forming strategies to manufacture individual tailored semi-finished products in term of a pre-distribution of material. These products feature variable sheet thicknesses and mechanical properties, which can be adapted to their case of applica-tion. Depending on the individual batch size, the blanks can be finished to functional parts by sub-sequent forming processes like deep drawing and upsetting, extrusion or incremental forming. In this paper the case of an incremental tooth-forming is mainly considered. Forming sequences and resulting loads are modeled and calculated by finite elements simulations for all discussed processes to serve as a basis for the design and dimensioning of the machine components and forming tools.