| 摘要 |
PURPOSE:To make it possible to form every shapes of open hole, and shorten the time of hole opening, by extruding a resin parison into the space of one set of devided molds, closing the one set of devided molds, pressing there compressed gas, inflating the parison, molding a hollow body made of the resin, forwarding a hole-opening tool, and forming a open hole at the wall surface of the hollow body made of resin. CONSTITUTION:A mold composed of one set of devided molds 1, 2 are mounted to an ordinary blow molding machine. A parison is extruded and the devided molds 1, 2 are closed, then a hollow body W made of resin according to the shape of cavity 3 is molded by blowing there compressed gas, inflating the parison and pressing against to the mold surface. Here the hollow body W is shaped in such a state where the cutting edge 41 of a hole-opening tool 4 bites into the section thickness of the hollow body W. After cooling at the state where the compressed gas pressure for blow molding is retained, an air cylinder 5 is drived, and the hole-opening tool 4 is projected into the forwarded cavity 3, then open hole W1 is shaped. |
