Session: 02-02-01: Computer-Aided and Simulation Driven Design 1

Paper Number: 164893

Optimal Design of Die Casting Gating System for Parking Brake Housing to Prevent Gas Defects 

Die casting is a casting method that enables mass production of castings with high-quality surfaces by injecting molten metal into a mold at high speed and high pressure. However, if the gas entrapped during high-speed injection is not properly discharged from the product part, casting defects such as porosity could occur, leading to a decline in product quality. Optimizing injection conditions and improving gating system designs have been considered effective approaches to address this issue. Changing injection conditions could be conducted relatively easily by modifying the settings of the die-casting machine. On the other hand, improving the gating system design requires mold modifications, which involve significant time and economic costs. Therefore, Computational Fluid Dynamics (CFD) simulators have been widely utilized in the casting industry, including die casting, to optimize casting conditions and support the design of gating systems. However, in general, in design processes for gating systems, engineers determine the shape based on their design experiences or databases in conventionally designed gating system shapes, evaluate the CFD analysis results with determined shapes, and improve the gating system shapes through trial and error. As a result, designing gating systems for new product shapes or products with complex design constraints that do not exist in conventional databases makes it difficult to design appropriate gating systems, increasing the risk of casting defects. Therefore, the authors' research group has developed optimal design systems for die-casting gating systems that integrate CFD simulation with optimization algorithms. For example, we have developed a runner shape optimization system that minimizes entrained gas in the runner part using a curve optimization algorithm, as well as an automated overflow design system that estimates the flow direction of molten metal from velocity information, allowing the complete discharge of gas entrained molten metal from the product part without iterative calculations. In this research, we applied optimization systems to optimize the gating system design for housing used in parking brakes of cars, a product with stringent gating system design constraints due to its product specifications.  In particular, we analyzed the molten metal flow inside the product part using a CFD simulator, and the runner shape optimization system and the automated overflow design system were applied to achieve an optimized entire die-casting gating system. Finally, we produced two molds: one designed based on conventional gating system design methods and the other using the optimized design system. We applied these molds to an actual production line in the die casting foundry, and we evaluated the defect rate based on thousands of manufactured products. The results verified that the optimized gating system successfully prevented gas-related casting defects.

Presenting Author: Daichi Minamide Mie University

Presenting Author Biography: Daichi Minamide is a doctoral student at the Graduate School of Engineering, Mie University in Japan. He received his Master’s degree from the same institution. In addition to his research, he serves as a technical staff member at the Faculty of Engineering at Mie University. His research interests include casting engineering, fluid engineering, optimization, and automated design.

Authors:

Daichi Minamide Mie University
Ken’ichi Yano Mie University
Yasuhiro Hata Mie Die Casting Industry Co., Ltd.
Yusuke Yamashita Mie Die Casting Industry Co., Ltd.
Tadao Kondo Mie Die Casting Industry Co., Ltd.