| 摘要 |
PURPOSE:To mass-produce a titled pipe easily and at a low cost, by cold-forging successively a center recessed part of one end face, a hole in the axial direction of the center of one side part and a center recessed part of the other end face, and a hole in the axial core direction of the center of the other side part, and thereafter, extruding a part between holes of both sides, and subsequently, cold-forging a shake proof washer in both end parts. CONSTITUTION:The first work 4 is prepared by cold-forging a center recessed part 5 on one end face of a blank material 3 obtained by cutting a round bar and internal chamfering 6 of one end part. Subsequently, the second work 7 is prepared by forming on the first work 4 successively a hole 8 in the axial core direction in the center of one side part, a center recessed part 9 of the other end face, internal chamfering 10 of the other end part and external chamfering 11 of the other end part, by means of cold forging, respectively. Subsequently, the third work 12 is obtained by cold-forging a hole 13 in the axial core direction in the center of the other side part of the second work 7. Subsequently, the blank material 3 is formed to a pipe by pressing a part 15 positioned betwen the holes 8, 13, and external chamfering of one end part is executed, by which the fourth work 14 is obtained, and subsequently, an object pipe 1 having a shake proof washer in both ends is obtained by cold-forging a shake proof washer 2 in both end parts of the fourth work 14. |
