Development of loading devices to evaluate the stiffness of forging presses in realistic operating conditions

Due to their great influence on part accuracy and tooling preservation, the elastic behaviour and stiffness of forging presses have considerable impact on both technical and economical success of the forging operations. Accordingly, both manufacturers and users of forging presses need for practical guidelines, tools and reliable data to evaluate the elastic behaviour of presses and its effects on product geometrical accuracy. This paper deals with an innovative approach to model the elastic and dynamic behaviour of the overall system comprising workpiece, tooling and press and to evaluate its working accuracy. The paper focuses on the development of the two loading devices that together with the measurement of relative displacements between upper and lower beds of the press permit to evaluate the dynamic stiffness of forging presses in realistic operating conditions.