Manufacturing of Geared Sheet Metal Components Using Flexible Rolled Tailored Blanks

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.