| 摘要 |
PROBLEM TO BE SOLVED: To provide an injection molding device which, even when a thin molded article is injection molded, can prevent the occurrence of sinking and thinning while suppressing an overload on an injection device.SOLUTION: Since the ratio of the diameter φt of an injection port 21t to the inner diameter φb of a body part 21b of a nozzle 21 is in a range of 3:10 to 3:20, the pressure loss in the nozzle 21 due to a decrease in a cross section area can be reduced. Since a clearance Ga between a check ring 24 and a cylinder 22 is 50 μm or more and 100 μm or less, the pressure loss due to a back flow is reduced. Consequently, the filling performance of a resin is improved to enable filling of the resin into a cavity CA corresponding to a thin lens LP. At this time, the filling can be performed without excessively increasing the temperature of the resin and the temperature of molds 41, 42, so that molding can be performed without destroying the physical properties of the resin. In addition, the filling can be performed without excessively increasing the filling speed of a molten resin, so that loads applied to a servomotor and a screw 23 of an injection device 16, and the like can be reduced.SELECTED DRAWING: Figure 2 |
