SIMULATION OF THE DYNAMIC CHARACTERISTICS OF AN INJECTION MOLDING MACHINE BY THE BOND GRAPH METHOD

The present study deals with the estimation of the dynamic characteristics of the hydraulic system used in an injection molding machine. It is usually not easy to estimate its dynamic behavior, however, because the characteristics of the plastics as a load is not well analyzed. The aim of this study is to estimate the dynamic behavior of the plastics in the mold by bond-graph simulation. The hydraulic components used in the hydraulic circuit were decomposed into simple elements which were replaced with corresponding bond-graph elements, and finally a bond-graph diagram for the hydraulic circuit was obtained. On the other hand, six models for the behavior of the plastics had been assumed, and after calculation using those models these results were compared with experimental results. One of them was selected as the most preferable model, which best simulates the behavior of the plastics.