Research On The Automatic Generation Technology For The Gating System Of Injection Mold

Gating system is the channel of plastic melt, when filling the mold cavities. Its design will directly affect the quality of products formed by injection mold. The traditional process of gating system design usually needs too many interactive operations. When the design of gating system is complete, you also need to manually import the gating system into flow simulation software for mold filling analysis, which further resulted in a waste of time and resource. To improve the automatic level of the gating system design, an automatic generation system of gating system has been developed on the platform of UG NX.Firstly, the process of gating system design is analyzed deeply in the paper. According to the process, this paper sums up the key steps of gating system design. Then the framework of the system is proposed, and the key technologies in the system are introduced in details at the same time. The key technologies used in the system include the automatic design of runner layout, the reconstruction of runner centerlines on the complex parting surface of injection mold, and the three-dimensional modeling of gating system for CAD/CAE.Runner layout is an important part of gating system design. Based on the analysis of the topological features and structural forms of multi-cavity mold runner, a topology templates database of common runner units is constructed. By combining these runner units according to the rules,it can achieve the automatic design of runner layout. For a variety of layout schemes that may arise during the process of combination, a fuzzy evaluation method is designed to evaluate these layout schemes.During the generation of runner on the complex parting surface of injection mold, the runner centerlines need to be projected onto the parting surface. It may lead to interrupt or cusp issues when projecting the centerlines, which will affect the generation of runner. So the projected centerlines must be reconstructed. For the reconstructed centerlines, the paper uses an algorithm based on the maximum spanning tree of graph to check their topological structure.The three-dimensional modeling of gating system for CAD/CAE uses the runner centerlines as a transformational bridge between CAD and CAE model. When the solid model of gating system is being generated, the data needed by finite element analysis is also added onto the runner centerlines as their attributes. By extracting these attributes, it can achieve a rapid transformation from CAD model to CAE model.On the basis of the above research achievement, a prototype system has been developed. And some cases have been studied to illustrate the module function and prove the great significance of the system to improve the efficiency and quality of gating system design.