Optimum injection considering shot timing for die casting by using CFD simulator

Die casting is adequate for mass production and it has the advantage of being able to yield a complicated shape accurately. A defect of die casting for high-speed injection molding is the occurrence of shrinkage cavities. To avoid the shrinkage cavities, velocity control of a plunger is very effective. However, the velocity control input is manually constructed by skillful workers because analysis behavior of molten metal is very difficult and the injection molding is performed in invisible places in the mold. In this paper, fluid behavior and quantity of air entrainment caused by a die casting plunger movement are analyzed by using CFD. The optimum velocity control input of die casting plunger is calculated in order to enable the reduction of air entrainment and prevent the occurrence of shrinkage cavities in die casting product. An optimization is performed by the genetic algorithm incorporating CFD simulator.