APPARATUS FOR MANUFACTURING PIPE

摘要

PURPOSE:To prepare a pipe having a smooth surface and to eliminate the leakage of the liquid passing through the pipe to the outside of the pipe by providing a magnetic core having a taper part whose diameter is successively increased in the feed direction of a resin and the core position control body arranged so as to cover a part of the core and forming a magnetic field changing the position of the core in the flow area of the resin extruded from a pipeline. CONSTITUTION:A columnar core 14 is inserted in a pipeline 18. A leading end core part 13 is equipped with a taper part 13a having a taper surface whose diameter is successively widened toward the downstream part in a resin feed direction and integrated with the core 14 through the taper part 13a. A core position control body 17 is arranged on the resin emitting side of the pipeline 18 so as to cover a part of the outer periphery of the leading end core part 13. Since both of the inner peripheral part of the core position control body and the outer peripheral part of the leading end core part 13 are set to the same polarity in the opposed surfaces thereof, repulsive force is generated between both of them to fix the leading end core part 13 at the center position of the core position control body 17. Therefore, a bridge inserting the core 14 in the pipeline 18 in concentric relation thereto is not required within the pipeline 18 and a pipe having no bridge line remaining therein at all can be prepared.