| 摘要 |
PURPOSE:To save labor hours and cost for application of the titled manufacture, by a method wherein an outer wall having cylindrical parts whose inside diameter is identical with that of trough parts at fixed intervals are molded continuously, an inner wall which is made to fuse to the inside of the trough part and that of the cylindrical part of the outer wall is molded continuously, an obtained double wall molded member is cut off with the cylindrical part, the diameter of an end of the cut-off molded member is expanded and a port is molded. CONSTITUTION:Simultaneously with molding of an outer wall 3 molten synthetic resin is extruded cylindrically into the outer wall 3 through an annular second resin passage 12 of a molten resin extruding part 1 and an inner wall 4 which is made to fuse to the inside of a trough part 32 and that of a cylindrical part 33 of the outer wall 3 is molded continuously. The inner wall 4 fused in this manner is fed to a cooling cylinder 5 side along with the outer wall 3 according to running of molding blocks 21, 21', cooled, cured, unified and then the molding blocks 21, 21' are released. An obtained double wall molded member A is cut off at about the middle of a cylindrical part 33 and made into a double wall molded member B which possesses double wall cylindrical parts 6, 6 on both ends and is in a predetermined length. Then the double wall cylindrical part 6 of the one end of the double wall molded member B is made to soften, a sizing component whose outside diameter is about the same as that of the double cylindrical part is inserted for diameter expansion processing. |
