HAN Jianwen

JIAN Bin

YAN Guangrong

LEI Yi
School of Mechanical
Engineering & Automation,
Beihang University,
Beijing 100083, China

Abstract: Surface classification, 3D parting line, parting surface generation and demoldability analysis which is helpful to select optimal parting direction and optimal parting line are involved in automatic cavity design based on the ray-testing model. A new ray-testing approach is presented to classify the part surfaces to core/cavity surfaces and undercut surfaces by automatic identifying the visibility of surfaces. A simple, direct and efficient algorithm to identify surface visibility is developed. The algorithm is robust and adapted to rather complicated geometry, so it is valuable in computer-aided mold design systems. To validate the efficiency of the approach, an experimental program is implemented. Case studies show that the approach is practical and valuable in automatic parting line and parting surface generation.

Key words: Visibility  Ray-testing  Surface classification  Parting line  Demoldability analysis