| 摘要 |
PURPOSE:To obtain an injection molding method by which in injection molding a molded item with hollows in a plurality of predetermined parts thereof, a dispersion of a gas blowing amount for each predetermined part from a specified value can be prevented even in the presence of a variation in resin pressure in the predetermined parts without requiring a larger device and remarkably increasing a facility cost. CONSTITUTION:A melt resin is injected into a molding space 9. Thereafter, a gas is blown into each of a plurality of thick-wall parts of a molded item 10. At this time, resin pressures in these thick-wall parts are respectively detected. Based on the detection values, control valves 18A-18D provided in gas supply paths to the thick-wall parts are so controlled that a gas is blown into the thick-wall parts in the order of increasing resin pressure with the highest one first, or gas blowing is finished in the order of decreasing resin pressure with the lowest one first. In this manner, a gas of a predetermined amount is blown into each of the thick-wall parts. |
