| 摘要 |
PURPOSE:To obtain the socket part of a desired shape certainly, even though the heating temperature of a plastic pipe is low, by blocking the pipe end of the plastic pipe with a pipe end blocking member provided to slide freely on a second mold and evacuating to a vacuum, pulling out it. CONSTITUTION:After the diameter of the rising part 1a of a first mold 1 is expanded until it is protruded by a predetermined height to an outer peripheral face of a second mold 2 and a pipe end blocking member 5 is approached to the rising part 1a of the mold 1, a pipe end of a preheated plastic pipe P is fitted in the mold 1 until a predetermined length of a pipe end part P'a comes out to the mold 2 side. Then, making a vacuum by exerting a negative pressure through a vacuum sucking hole 11b the blocking member 5 is moved to an arrow direction. A diameter of the end part P'a is contracted due to an action of a sucking force and the end part P'a is contacted to the rising part 1a and the mold 2 when the blocking member 5 is pulled out from the pipe P. Then, a socket part Pa being water-cooled, solidified, the diameter of the mold 1 being contracted and the pipe end blocking member 5 being moved to a guide 3 side, the plastic pipe P is pushed out from a forming mold. |
