| 摘要 |
PURPOSE:To form a hollow nozzle blade applying load perpendicular to the tube axis and reduce the number of manhour by inserting a hollow preliminarily formed product of circular sectional form in which a coined end of a plate is joined to another end between upper and lower dies, and closing the dies while applying liquid pressure to the hollow part. CONSTITUTION:A plate 8 is cut to specified shape and dimension and coining is performed by upper and lower dies 9a, 9b for working at a specified position on an end. The coined plate 8 is inserted between upper and lower rolls 10, 11 of triple rolls and bent to give circular sectional form. Then, another end 8b of the plate 8 is butted and welded to the coined part 8a to form a preliminarily formed nozzle blade 12 provided with a hollow tube 12c having a hollow part 6 and an outer port 12b. The preliminarily formed product 12 is inserted between upper and lower dies 13a, 13b for forming nozzle blade. Pressure medium 14 is introduced to inside of the hollow tube 12c, and upper and lower dies 13a, 13b are closed while applying liquid pressure. |
