Research On The Design Of Core-pulling Mechanism In Injection Mold Based On Knowledge

The structures of plastic products are more and more complex, and the plastic partsthose have lateral concave-convex structures are more and more. Side core-pullingmechanism should be used for this kind of parts, which not only causes more problemson mould design, but also needs higher request on molding quality. Now，the sidecore-pulling mechanism design still highly relies on the designers’ knowledge andexperience, and the designers need to do a large number of manual operations andcalculations, which reduce the mold design efficiency. Therefore, the development of anintelligent system of side core-pulling mechanism has a great significance to improve theefficiency and quality of injection mold design.On the basis of summary of design knowledge and experience of side core-pullingmechanism, this paper applies knowledge-based engineering, rule library and knowledgelibrary are built. With in-depth analysis of structure characteristics of the typical sidecore-pulling mechanism, this paper uses parametric modeling technology and associatedtechnical, a standard component library of side core-pulling mechanism is created. In thispaper, for the given parting direction, a recognition method of undercut features wasproposed. The geometric properties of part’s surfaces were analyzed to identify all thefaces of undercut features. Then a graph-based recognition method was used to get thetype of undercut feature, Face Adjacency Attribute Graph (FAAG) of undercut featurewas created, and the recognition rules were defined for sub-graph matching. Rule-BasedReasoning is used to achieve an appropriate side core-pulling mechanism. By automaticdesign of forming head and automatic load of standard part, the intelligent design ofcore-pulling mechanism is achieved.At last, a design example is used to show the whole process of side core-pullingmechanism design. The results show that system of side core-pulling mechanism researched in this paper can improve the efficiency and quality of injection mold design.