Understanding energy consumption of hydraulic press during drawing process

Prediction of manufacturing equipment’s energy consumption plays an important role in selecting appropriate process parameters for energy saving. However, it is difficult to model the energy consumption of metal forming equipment during the drawing process characterized by variable process parameters and dynamic loads. In this paper, a model was developed to quantify the energy consumption of a typical hydraulic press during the drawing process under a range of operating conditions. The hydraulic press studied consists of two different circuits and two controllable parameters, i.e., punch velocity and blank holder force can be set for drawing processes performed. To start, the energy flow during the drawing process was analyzed by using the energy conversion mechanism and components’ specifications to understand the detailed energy characteristics of each circuit. Then, orthogonal experiments including these two parameters at three levels were designed and carried out to find significant parameters. Finally, the contribution of each parameter, which was obtained from the analysis of variance (ANOVA) of the experimental results, was used to simplify energy flow modeling efforts. Consequently, a model of the press was established and used to predict the energy consumption of the drawing processes with different parameters. Good agreement with the experimental results was observed. The model can be used to identify parameters for minimal energy consumption, while the approach could be adapted to develop an energy consumption model for different hydraulic equipment.