| 摘要 |
PURPOSE:To prevent defects from generating on the outer surface of a molded piece by a method wherein molding resin stock to be poured in a cavity is caused to once collide against the collar part provided on an inner peripheral part forming core in a mold cavity before the stock is poured in the mold cavity. CONSTITUTION:During molding, molding stock is poured from the nozzle of an injection machine through sprue 16, a runner 17 and a gate 18 into a cavity 15 in order to form a molded piece 29. In this case, the molding stock to be injected through the gate 18 into the cavity 15 collides against the collar part 14a provided on an inner peripheral part forming core 14, resulting in once being stored in the gate 18 side of the collar part 14a and then realizing laminar flow state in the stock when the stock clears the collar part 14a before the stock fills the cavity 15. As a result, the development of flow marks, jetting phenomenon and the like, all of which are apt to develop on the outer surface of a thick- walled molded piece 29, is suppressed. |
