The Hydro-Multipoint Forming Process of Complex Sheet Metal Parts

The paper presents the concept of a new tool for the sheet metal blanks deformation which is based on the hydro-multipoint method. In this method the upper die with pins is replaced with a hydraulic pressure chamber. The blank sheet is placed between two flexible interpolators and it is deformed under the action of the pressure applied from the hydraulic chamber until it takes the shape of the multipoint die located at the bottom of the equipment. A critical review of the main hydroforming and multipoint forming methods is done. Then, a simulation model for the new hydro-multipoint forming tool is developed. Material thickness, stresses and part dimensions are analysed. A mechanical hydro-multipoint forming tool which was designed and manufactured based on the new concept is presented. Using this tool a number of experiments are done. The real parts are evaluated in terms of surface quality and parts dimensions. The experimental results come to validate the numerical ones. Finally, it was concluded that this new die concept could be used in manufacturing complex sheet metal parts.