| 摘要 |
PURPOSE:To enable setting of low upsetting load and to improve forming accuracy by pressing a blank material with plural sectional dies simultaneously with pressing said material with upper and lower punches thereby obtaining a press- formed inner ring. CONSTITUTION:A blank material is axially pressed by upper and lower punches 47, 37 when a ram 45 is moved downward after setting of the blank material. As the ram 45 moves further downward, an upper die 46 depresses sectional dies 41-41 together with a holder 34 and moves the dies 41-41 in the axial center direction between the holder 34 and the die 46 by sliding on slopes 33-33. The blank material is then axially pressed by the upper and lower punches 47, 37 and at the same time the material is pressed in the axial center direction by the dies 41-41, thus the blank material receives simultaneous pressing in the axial and axial center directions. When the downward movement of the ram is completed, the blank material is formed to the press-formed inner ring by the punches 47, 37 and the six dies 41-41. |
