| 摘要 |
PROBLEM TO BE SOLVED: To precisely manufacture gear parts at a profitable cost by forming a disk-like blank into a cupped preform having the bottom part and the annular wall, forming an annular web part extended from the bottom part to the reverse side of the annular wall and strain- and finish-forming the annular wall into an outline formed part in the peripheral position. SOLUTION: The disk-like blank is deeply drawn into the preform having the rotational symmetry to the rotating axis. Successively, the blank is held between two halves in a strain forming device and a split roller for shearing the outer edge of the bottom part is fed in the radial direction. At this time, the annular web part extended to the reverse side of the annular wall at the bottom part and projecting the bottom part to the axial direction. Therein, the annular wall and the annular web part are mutually positioned so as to slip to the axial direction and the radial direction. The annular wall is pressed to the outer outline of the jig halves and spread to a first position 24 of the peripheral position 23 in the gear parts 20 to arrange the inner outline 26. At the same time, the annular web part is formed in a second position 25 having the outer outline 27 and outer tooth. |
