| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing a cylindrical metal piece with a polygonal part in which the contour of the cylindrical metallic fixture with the polygonal part is easily and simply forged at a relatively small forging load, the burden on a die is suppressed, and the cylindrical metal fixture is durable for a long term use. SOLUTION: By forging a columnar stock A, a first recessed part D6 and a second recessed part D7 which are recessed inwardly in the axial direction are formed at the center of both ends of the stock A. At the same time, a head part D2, a polygonal part D4 and a leg part D5 are formed. An intermediate forging D having the contour of the cylindrical metallic fixture with the polygonal part and having the first recessed part D6 and the second recessed part D7 in the center of both ends is formed. By further forging the intermediate forging D, the first recessed part D6 and the second recessed part D7 are pierced to form a final forged stock having the contour of the cylindrical metallic fixture and having storage holes 6, 7 and 8 to be penetrated in the axial direction is formed in the center. COPYRIGHT: (C)2004,JPO&NCIPI
|
