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PROCEDURE FOR THE DESIGN OF THE SYSTEM OF EXPULSION RODS FOR A MOLD
P201631252
Method for designing the ejection rod system for an injection mold comprising: creating a grid of flat nodes (nk) on a plane perpendicular to the movement of the mold cavity; determine the points (pij) of the piece (m ') corresponding to the intersection with a line (rt) perpendicular to the plane passing through each node (nk); calculate the thickness (eij) corresponding to each point (pij); identify the points where they exist (pijr) and where there are no (pijv) thickness changes; determine as points (pijexp) candidates those points (pijv) whose first surrounding surface does not contain any point (pijr); calculate the number of points (pijr) contained in a second surface surrounding each point (pijexp), where the second surface is greater than the first surface; and select as points (pijexpo) of expulsion those points (pijexp) whose number of points (pijr) contained in the second surface constitutes a local maximum.
A new procedure for the automated derivation of the position of the ejector rods required to eject a plastic part to be designed. The proposed procedure will help injection mould designers to systematically obtain the optimal ejector rod position, substantially reducing the interaction time between product designers and mould designers in validating the design before manufacturing.