MANUFACTURE OF MOLDING CORE MOLD OF PIPE JOINT HAVING BRANCHED PART

摘要

PURPOSE:To manufacture a molding core mold in large quantities and at low cost by making use of a split mold which is simple in structure and is identical with each other, by a method wherein a tubular molten material is cut off at the center and an obtained branched mold is connected with a cylindrical swollen-out part formed on a main body mold so that an end part of the branched mold is fitted in the cylindrical swollen-out part. CONSTITUTION:A mold member 13 for shaping a cylindrical swollen-out part positioning at an intermediate part of a split mold 1 is removed, the split mold is constituted of a molding member 11 for shaping one side connecting opening molding part and a molding member 12 for shaping the other connecting opening molding part and blow molding of a tubular molded material 9 is performed by making use of the split mold. The tubular molded material 9 is but off at the center of the same and two pieces of branched molds 4 are obtained. The diameter of an end of the branched mold is expanded and made into a port part 41 whose diameter has been expanded. On the one hand, the other end becomes a small diameter part 42 having the inside diameter which is about identical with the outside diameter of a cylindrical part 321 of the tip of a swollen-out part 32 of a main body mold 3. A small diameter part 42 of the branched mold 4 is fitted in the cylindrical part 321 of the main body mold 3 and a molding core mold 8 of a T-shaped joint is manufactured by making an end face of the small diameter part 42 abut against an annular stepped part 322.