Load Simulator Design for the Experimental Validation of a High Energy Saving Methodology in the Automation System of Hydraulic Presses

The present paper deals with some preliminary design and simulation activities aimed at defining possible configurations of a system able to apply actions that can reproduce the working forces in hydraulic presses. The idea of developing this kind of system arises from the will to make experimental activities to validate the systematic methodology conceived by the authors that allows to get a significant energy saving in applications where hydraulic servo-axes are used. Keeping as guideline the development of a low cost and simple system, a solution based on the use of pneumatic cylinders has been considered. The configuration of the system, composed of four pneumatic cylinders connected in parallel, is set-up by means of an optimization process, and its behavior has been analyzed through simulations in Matlab/Simulink environment. The pneumatic configuration is also compared to a servo-axis system composed of a power drive system (servo-motor and relevant drive) and a ball screw. This preliminary investigation shows that the pneumatic solution is feasible mainly for sharply changing forces, as in hydraulic presses occurs, while if a load force set-point should be accurately followed, the servo-axis solution would be preferable. The results show that, at the aim to have a load simulator for the validation of the methodology conceived by the authors, considering the working loads of hydraulic presses, the use of the pneumatic cylinders seems to be a good solution.