Research on automatic generation technology of ejector pin for injection mold

When having narrow slot features in the mold core, the molded products cannot be smoothly removed from the mold core. Through ejector pin design, during the ejection process, the ejector pin can eject products to successfully leave the mold core. Under the framework of CAD software, this study developed the narrow slot feature recognition, integrated the mold design, and automated ejector pin production. Based on the geometric relationship of the surfaces, edges of the core’s narrow slot, this study summarized an algorithm to automatically recognize the narrow slot feature by programming an algorithm. Through computer programming calculation and judgment, the proposed method can automatically recognize narrow slot features to reduce the time at the recognition stage and record the diameters of the ejector pin and its coordinate position in feature parameters. At the mold design stage, through the acquisition of its parameters, it can automatically produce a suitable ejector pin. Through standardized design process, it can greatly shorten the design time to guide users to quickly complete the design, while reducing design errors to improve working efficiency by the automatic integration function.