Variable section extrusion mold and variable section extrusion molding method

摘要

A mold 24 which is installed to be movable in a direction orthogonal to the extrusion direction of the molding material and changes the area of the extrusion molding hole 31 to which the molding material is extruded, and can be moved forward and backward in the extrusion direction in the extrusion molding hole The mold is used for a variable cross-section extrusion die formed of a mandrel 27 provided with a tapered portion 27B which is installed in the outer periphery and has a tapered portion 27B whose outer dimensions gradually decrease from one of the forward and backward directions to the other. The mold is moved while pressing the molding material toward 24 to deform the extrusion hole 31, and the taper portion of the mandrel 27 is moved forwards and backwards into the extrusion hole to have an external shape in the longitudinal direction. The tubular molded article in which the dimension and the dimension of the inner mold are changed are extruded.