Displacement and dual-pressure compound control for fast forging hydraulic system

The poor energy efficiency is a big issue in the conventional electro-hydraulic proportional valve controlled fast forging system due to the huge throttling losses and overflow losses. Aimed to address this problem, a new compound control strategy of displacement and dual-pressure was proposed in this study. Firstly, the mathematic model of the main components was built, and the compound control strategy was designed depending on the different working conditions. Then, the overall control system was integrated for both down-stroke stage and return-stroke stage. The proposed control strategy was tested and evaluated in a 0.6 MN fast forging press. Results indicated that the input energy was reduced by 50% and energy loss decreased dramatically while control performance was good. Results also show that control performance and energy saving are significantly affected by the variation of Delta p and p(b). Overall, the proposed new control strategy could be used for the fast forging press with high energy efficiency.