EXTRUSION DIE OF EXTRUSION MOLDING MACHINE AND METHOD FOR MANUFACTURING EXTRUDED PIPE

摘要

An extrusion die for an extrusion molding machine and a manufacturing method of an extruded pipe are provided to prevent thickness of a cross-shaped reinforcing rod of the extruded pipe for manufacture of a spiral pipe from getting thinner toward the center, by arranging a central reinforcement extruded pipe in the inner center of a core. In an extrusion die for an extrusion molding machine, a core(130) is fitted and fixed to a cylindrical body(120) connected to a core cover(110) and a feed passage(140) through which formed resin supplied from a first extruder is fed is formed between the core cover and the body, and the core. A central reinforcement extruded pipe(150) connected to a second extruder is arranged in the center of the core. The core cover comprises a flange part combined to the body by a bolt(116); a taper part extended from the flange part; and a square extrusion part(113) extended from the end of the taper part in a straight line. If a square tube-shaped part of the core is arranged to a square extrusion hole formed in the square extrusion part, a gap(T1) is formed between the inner peripheral surface of the square extrusion part and the square tube-shaped part of the core.