| 摘要 |
PROBLEM TO BE SOLVED: To properly discharge air in a filling part with a simple structure, when filling molten resin in the filling part.SOLUTION: An injection molding device 1 comprises: a cavity 12 in which injected resin is filled; a vent hole 36 communicated with the cavity 12 and capable of discharging air in the cavity 12; and an ejector pin 50 for moving forward, from a closing position for closing an opening 36a of the vent hole 36 to a discharge position, for extruding a molded article from the cavity 12. The ejector pin 50 comprises a pin body 51, a tip part 52 disposed on one end side of the pin body 51 in an axial direction, and closing the opening 36a on an outer peripheral face when it is positioned on the closing position, and a groove part 54 having a groove 54b formed along the axial direction on the outer peripheral face of the pin body 51 on the axial direction center side, in which the groove 54b is exposed from the opening 36a when it is positioned on the discharge position. When the cavity 12 is filled with resin, the ejector pin 50 is retreated from the discharge position to the closing position.SELECTED DRAWING: Figure 5 |
