| 摘要 |
PURPOSE:To obtain a bent pipe with no generation of a material scrap by using a belt-shaped metal plate, in which large and small width parts alternately continue with one edge in a lengthwise direction in a straight line and the other edge in a wave curve, as a material, forming a double-hook in the straight line edge and a single-hook in the curved edge, helically winding the belt-shaped metal plate and fitting the adjacent single-and double-hooks. CONSTITUTION:In a coiled belt-shaped metal plate material 3, an L-shaped curved part is worked in both side edges by a omicronapprox.=ding roll 11 and formed in a double-hook of squared shape with one side open by a molding roll 14. Two sheets are cut-taken by a female roll 18, in which a groove of wavy curve is engraved in the periphery, and by a male roll 20, provided with a protrusive streak of wavy curve, and both cut edges are formed in a single-hook. One of the belt-shaped metal plate 3 is directed toward a helically winding machine 27, and the other is accumulated in a drum 28. In the helical winding machine 27, the belt-shaped metal plate material 3 is helically wound outside a roll 30, and work of meshing and fitting the double-hook with the single-hook is performed by a reciprocating roll 36. A manufactured bent pipe 1 is cut into a predetermined length by a grinding wheel cutter. By the constitution in the above, the cost down can be contrived with no scrap at all. |
