Core and cavity generation method in injection mould design

In a computer-aided injection mould design system, the generation of parting surfaces and the creation of core and cavity blocks is usually a bottleneck. The parting surfaces and core/cavity blocks are created based on the parting direction and parting lines. Here, the architecture of an injection mould design system is proposed on the basis of the practical information flow and processing steps in mould production lifecycle. In this architecture, the methodology to generate the parting surfaces and the core/cavity blocks is proposed. To generate the parting surfaces, the parting line edges are classified and the extruded directions specified to the different groups of parting line edges. Extruding the parting line edges to the boundary of the core/cavity bounding box generates the parting surfaces. To create the core/cavity blocks, the Boolean regularized difference operation (BRDO) is used and the related algorithms are presented. The criterion to identify whether the undercut features need local tools for moulding is proposed. The case studies illustrate and validate the methodology to generate the parting surfaces and core/cavity blocks.