| 摘要 |
PROBLEM TO BE SOLVED: To provide a forming method for forming a forged product without developing the underfill at one-end side in the axial direction of a tooth tip and a tooth-shape in the method for forming the forged product having the tooth-shape at the outer periphery and a through-hole in the axial center part. SOLUTION: The forming method for forming the forged product W3 having the tooth-shape 63 on the outer periphery and the through-hole 96 in the axial center part comprises: an intermediate forging process, in which a pre-forged material W1 having almost the same diameter as the addendum circle diameter of the tooth-shape 63, is pressed in from one-end side in the axial direction of the pre-forged material W1 into an intermediate forging material forming die 33 having a tooth-shape forming part 38 in the inner periphery, and the tooth-shape is formed on the outer periphery of the pre-forged material W1 and at the same time, the axial center part at one-end side of the pre-forged material W1 is pressed with a first punch 34 to form a first recessed part 71 in the axial center part at the one-end side, and the intermediate forged material W2 forming the tooth-shape by fluidizing the thickness of the axial center part at the one-end side into the outer periphery at the one-end side in the axial direction of the tooth-shape; and a pierce-forming process, in which the through-hole 76 is formed by punching out the bottom part 75 in the first recessed part 71 in the intermediate forged material W2 and thus, the forged product W3 is formed. COPYRIGHT: (C)2008,JPO&INPIT
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