| 摘要 |
PURPOSE: To provide an injection molding method of an automobile bumper and its injection mold wherein low pressure injection molding of a thin wall bumper can be carried out, and appearance of the bumper is improved. CONSTITUTION: A mold 2 wherein a gas channel guide part 21A of which a space is thicker than that of the periphery, a lightening cavity 27 provided outside a resin fluid end position of a main cavity, and a gas force fitting channel 26 force-fitting gas to a rear surface of a bumper are provided, is used. After filling resin, gas is injected, and a gas channel is formed in the resin. Besides, gas is force fitted from the gas force-fitting channel 26. The resin is stuck fast to a surface of the main cavity by both of the gas channel gas and the gas from the gas force-fitting channel 26. Thereby, gas pressure, injection pressure, and clamping pressure are lowered, and besdies appearance of the bumper is improved. |
