| 摘要 |
This method entails injection-molding a spacer (1) using an injection molding die having resin passages designed in such a manner that a plurality of gates (6) are arranged in a longitudinal direction at a position that corresponds to the outer peripheral surface of a sidewall (4) in which a plurality of arcuate peripheral surface sections (2) are connected to one another with waist parts (3) interposed therebetween, cooling the spacer while leaving the runner (7) which is connected to the gate (6) after opening the mold and ejecting the spacer, and then cutting off the runner (7). By doing so, when using injection molding to produce a water jacket spacer which is built-in to the interior of a water jacket, and which controls the flow of coolant, deformation in the post-molding cooling step is prevented, while enabling high-productivity production without being affected by design restrictions caused by draft angle. |
