EXTRUSION METHOD AND EXTRUSION MECHANISM

摘要

PROBLEM TO BE SOLVED: To provide an extrusion method and extrusion mechanism for pipe-shaped articles P capable of averting the fracture due to tension even if the length of the pipe-shaped articles to be extruded is set large and a drawing rate Sp/Sw is set small. SOLUTION: An insert punch (22) is made slidable relative to a punch sleeve (21) and the advance of the insert punch (22) is stopped when a small-diameter stem part (22b) of the insert punch (22) arrives at a small-diameter hole part (11b) of a die hole (11). The extrusion of a workpiece pipe (W) by a punch sleeve (21) is performed while the stop state of the insert punch (22) is held. COPYRIGHT: (C)2004,JPO