| 摘要 |
A ball joint 10 includes a first member 12 having a ball section 14 and a second member 15 having a socket 16. Ball section 14 is accommodated and supported inside socket 16. A pair of dies 20, 30 sandwich a wall 18 surrounding an opening 17 of the socket 16, and are configured to approach each other gradually, utilizing small repetitive vibrations that include an approaching and separating action, thereby intermittently pressing the wall in an inward radial direction. During each interval of the intermittent pressing action, a supporting and rotating device 40 rotates socket 16 (second member 15) in small increments about a central axis C2 of socket 16. Consequently, dies 20 and 30 successively press against a multitude of points on the circumference of the outer surface of wall 18 of the socket, thereby bending wall 18 inward so as to reduce the diameter thereof. |
