OPENING PART WORKING METHOD OF BACKER FOR ALUMINUM EXTRUSION DIE

摘要

PROBLEM TO BE SOLVED: To permit taper working for a curved part of a backer by eliminating a cutting defect due to a difference in the cutting speed of a surface and a rear face in taper working of the curved part by gas fusion cutting. SOLUTION: The opening part of a backer 2 for aluminum extrusion die, by gas fusion cutting, is worked to the shape having a taper widening an opening area from a die side (surface) toward a counter die side (rear face). Cutting of the curved part of the opening is worked while controlling the position of a fusion cutting torch 20 in the advancing direction so that a fusion cutting speed ratio of the surface side and rear face side is 1:<=1.5. To this end, the fusion cutting torch 20 is mounted to the wrist axis of a robot, a robot wrist angle in cutting is controlled so that the cutting speed ratio of the surface and rear face of the curved part of the opening is 1:<=1.5.