PURPOSE: To manufacture a three dimensional extruded material having a sectional shape changed in the longitudinal direction by changing over the position of the tip forming part of a working body for forming during extrusion.
CONSTITUTION: A working body for forming 4 of the male die 3 of a port hole die 1 is moved back and forth. A small diameter part 4b is provided together with a convergent tapered part 4c at its tip and a forming part 4d having a circular outer periphery on the working body for forming 4. When the working body for forming 4 is moved back and forth by giving hydraulic pressure to a large diameter piston part 4a, the clearance between the forming hole 2a of a female die 2 changes and the thickness of the extruded material can be changed. The three dimensional extruded material having a sectional shape changed in the longitudinal direction can be manufactured.
SUGIO EIJI
MICHISAKA KOUZOU
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