Determination of 6 stiffnesses for a press

The industry is increasingly demanding for better tolerances at cold forged products caused by the tough competition at the market. Near net-shape or net-shape production save resources for machining and reduce therefore also the material costs. During the forming process, the reaction forces from the workpiece will result in deflections of the press, which will decrease the tolerances of the component. At present, it is possible to measure the reaction forces from the workpiece, for instance by use of the model material technique as described in [1-2]. If the stiffness and clearances of the press is known too, the final dimensions can be predicted by divide the force by the stiffness and add the clearance. If the stiffness of the press is known, it is possible to optimize the orientation of the workpiece too, so the direction, in which the best tolerances is demanded, is equal to the direction in which the press has the highest stiffness. Furthermore, knowledge about the stiffnesses of all presses in a production system makes it possible to choose the press which best fit to a specific process.