Device and method of producing ball joint

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.

主权项

1. A die for manufacturing a ball joint having a ball accommodated inside a socket that includes a wall having an outer surface, the die comprising:
a concave surface-shaped pressing surface which abuts against the outer surface of the wall of the socket and presses the wall in an oblique direction having an inward radial direction component and a rearward axial direction component; wherein:
the die is used to reduce a diameter of the wall of the socket by repeated and intermittent pressing in an inward radial direction against the outer surface of the wall of the socket;the pressing surface has a first subsidiary pressing surface and a second subsidiary pressing surface;each subsidiary pressing surface has a substantially spherical shape characterized by a radius and a center of curvature; andat least one of the radius and the center of curvature of the first subsidiary pressing surface differs from the respective radius and the center of curvature of the second subsidiary pressing surface.