| 摘要 |
PURPOSE:To prevent a thick wall part from deforming by supplementing the shrinkage consequent upon the solidification in the thick wall part by a structure wherein a mechanism to locally pressurize the thick wall part of a resin molding in a molding die. CONSTITUTION:When molten resin is cast from an ingate 9, the molten resin flows through a runner 10 and a gate a in 10a cavity 6. A compression pin 15 is displaced so far by the pressure of the molten resin against the spring force of a coiled spring 17 until the lower end of the compression pin 15 abuts against the underside of a spring receiving chamber 11a. When the resin in the gate 10a starts to solidify, the pressure in the cavity 6 becomes lower due to the shrinkage consequent upon the solidification of the resin. Especially, the outside part of a boss part 5a having a thick wall part deforms so as to dent inside. At this time, the compression pin 15 is raised by the spring force of the coiled spring 17 so as to press the ceiling of the boss part 5a having the thick wall part. Since the shrinkage consequent upon the solidification of the thick wall part 5a, which is still in un-solidified state, is supplemented by the resin shifted by said pressing, the outside part of the boss part 5a solidifies without deforming inside. |
