Development of an Automated Mold Design System Based on Product Geometry

The demand for shorter lead times, higher quality, and lower costs in mold manufacturing is increasing in the mold industry. In injection mold manufacturing, determining the parting surface is a crucial task. However, as molds are produced as custom-made products, mold design, including the determination of the parting surface, relies heavily on the experience and intuition of experienced engineers. Therefore, this paper proposes a system aimed at supporting the automated design of injection molds. In this system, based on a computer-aided design (CAD) model in the standard triangulated language (STL) format of the input product shape, the system first corrects misalignments in position and rotation that may have occurred during the design phase. It then determines the appropriate position of the parting surface to enable the proper removal of the product. Finally, the system outputs a CAD model of the mold with the determined parting surface. As this system automates the entire process—from loading the product model to determining the parting surface and outputting the mold model—it significantly reduces design time. To verify the validity of the proposed mold design support system, mold models were generated using the system, and actual machining was performed using an NC machine tool. The verification results confirmed that mold models could be successfully generated from the CAD model in the STL format without any issues. Additionally, the practicality of the molds was validated through actual machining, demonstrating the usefulness of this system in automating mold model generation.