Multi Shape Sheet Hydroforming Tooling Design

Abstract

In order to value the process of variables influence in sheet metal hydroforming, a special hydroforming cell has been developed. Generally, sheet hydroforming is obtained using appropriate press tooling. This option requires large investments completely dedicated to this technology of production. As an alternative, conventional hydraulic presses can be used for sheet hydroforming in combination with special hydraulic tooling named “hydroforming cells”. A special “hydroforming cell” concept has been developed to perform experimental analysis for different shapes using the same tooling set up. CAE tools had a strategic role just to develop the best layout and to find the optimum solutions for the process variables. FEA has been used to define the distribution of the blank holder variable forces: a solution which implies the use of twelve independent actuators have been implemented. The position and the load path of each one of them has been chosen for each formed shape, in accordance with the FEA results. Customized actuators have been used to solve interferences between mechanical parts of the hydroforming cell. For this specific aspects the virtual 3D design was necessary for the appropriate decisions. The developed process system is very effective so that is possible to set up experimental campaigns for sheet hydroformed components.

Computer Aided Simulation as valid tool for sheet hydroforming process development

“…Blankholder has a strategic role in metal forming processes because, thanks to its action, it is possible to manage the sheet flow in as a control parameter for possible ruptures and/or wrinkles [3]. Within a larger activity oriented to establish effective connections between process performances and its variables for sheet metal hydroforming, authors [4] have developed a numerical procedure which aims to increase the numerical simulation reliability. Each die component is verified in terms of stress and strains distribution under working conditions generated by the hydroforming process.…”