| 摘要 |
PROBLEM TO BE SOLVED: To provide a die for extrusion, which can efficiently manufacture a flat multi-hole tube having few defects and faired holes. SOLUTION: The die for extrusion is used for forming the flat multi-hole tube having a plurality of holes arranged so as to have an interval between them in two lines. A plurality of column shape projections 4, 5 for forming the lines of holes are provided on a base body 3 in two lines. The column shape projections arranged on the different line are alternately arranged zigzag along the line. Recessed portions 6, 7 between projections are formed on the base body 3 so as to elongate from the outside of the column shape projection in one line toward the column shape projection in the other line. When the extrusion is carried out, the flow of material is smoothly carried out because the material uniformly flows. As a result, the flat multi-hole tube having the faired multi-holes and few defects can be manufactured. COPYRIGHT: (C)2006,JPO&NCIPI
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