| 摘要 |
PURPOSE:To produce an eye joint of good accuracy efficiently at a low cost by forming one end of a round bar blank shaft of a required length to an approximately spherical shape by cold forging and plainshing both side faces of this approximately spherical head part then piercing a circular through-hole at the center. CONSTITUTION:One end of a round bar blank shaft 1 cut to a required length is pressure-formed with cold forging dies, whereby a head part 9 of an approximately spherical shape having no sharp ends is formed. Thence, the head part 9 is placed on the horizontal axial line of another cold forging die and the two surfaces are pressure-molded at home, whereby both side faces of the head part 9 are formed to planes 5 parallel to the axial line of the shaft part 1. A circular through-hole 3 is pierced by a blanking press using a punch to the center of the planes 5 of the flat circular head part of a true circular obtained in this way, whereby an eye part 2 is formed. After these forming, required working including spot facing or tapping of the passage hole in the axial center of the shaft part 1 and the eye part 2 is carried out, whereby the eye joint is produced. |
