| 摘要 |
PURPOSE:To manufacture a hollow blade of high precision at a low cost by forming a hollow pipe-like body by bending a blank plate whose one end is coined. by means of a completely sealed two-pieces mold. CONSTITUTION:A blank plate 10 whose one end is formed into a coining part 10a is bent by a three-rolls bender, and the coined part 10a is welded to the other end of the blank plate 10 in order to form a hollow, pipe-like body. After this hollow, pipe-like body is filled with lead 20, it is formed into a hollow blade by using a completely sealed two-pieces mold 22. Then it is heated to remove the lead 20, leaving a hollow internal space. |
