A hybrid parting method based on iterative surface growth algorithm and geometric mouldability

Abstract

A parting methodology to identify cavity and core surfaces, outer and inner parting lines, and undercut features based on surface topology and mouldability reasoning is presented in this paper. The approach first determines a cavity seed surface and a core seed surface. Then, the cavity and core surface groups are searched using the proposed iterative surface growth algorithm. Meanwhile, a concept of pseudo-straddle surface is introduced to deal with model geometry imperfection and free-form surfaces with imperfect draft angles. Subsequently, the outer and inner parting lines are identified using the proposed algorithms and criteria. The undercut features are finally identified based on the results of parting lines and associated surfaces. Since the approach is fully independent of the complexity of the geometry structure, it thus gives satisfactory results for models with complex geometry features.