| 摘要 |
PURPOSE: To injection mold a long and narrow, thin-walled closed-end cylindrical body in the even wall thickness by sensing that resin is backflowed in the state of retaining a core pin not to fall and then deforming the core pin so that a space between a cavity and the core pin is even all over. CONSTITUTION: A recessed section 8 of a top section of a second core pin 7 is fitted firmly into a fitting protruded section 3. Resin is flowed in from a gate opening 4 in the above state. The resin flowed in from the gate opening 4 is guided into a cavity 2 through a channel section 9. At that time, one end of the second core pin 7 is fitted into the fitting protruded section 3, while the other end is fixed to a core plate 11, and the pin is not fallen or bent by the resin pressure. The state that the resin flowing to almost a middle section of the cavity 2 is visualized or sensed by a sensor, and the second core pin 7 is moved backward to form a space between a first core pin 6 and the cavity 2 even all over. Also the resin is flowed into the cavity 2, and resin is filled in a site where the top section of the second core pin 7 exists to mold a molded product. |
