An apparatus to produce a self-piercing and clinch nut, the apparatus comprising:
- a first forging die assembly configured to subject a blank to first processing, the first forging die assembly comprising:
- a first die comprising a first insert hole and a first inner peripheral wall defining the first insert hole;
- a first cylindrical insert comprising a first platform, the first cylindrical insert being fitted in the first insert hole with the first platform opposed to the blank so as to define a first processing space in which the blank is to be processed, the first platform comprising a first side wall, the first side wall and the first inner peripheral wall defining a first surrounding groove;
- a first punch movable to and away from the first processing space;
- and
- a first pin fitted in a first hole of the first cylindrical insert;
- a second forging die assembly adjacent to the first forging die assembly and configured to subject the blank to second processing after the blank has undergone the first processing in the first forging die assembly, the second forging die assembly comprising:
- a second die comprising a second insert hole and a second inner peripheral wall defining the second insert hole;
- a second cylindrical insert comprising a second platform, the second cylindrical insert being fitted in the second insert hole with the second platform opposed to the blank so as to define a second processing space in which the blank is to be processed, the second platform comprising a second side wall, the second side wall and the second inner peripheral wall defining a second surrounding groove;
- and
- a second punch movable to and away from the second processing space, an inner peripheral length of the second inner peripheral wall in the second surrounding groove decreasing as a distance from the second punch increases;
- a third forging die assembly adjacent to the second forging die assembly and configured to subject the blank to third processing after the blank has undergone the second processing in the second forging die assembly, the third forging die assembly comprising:
- a third die comprising a third insert hole;
- a cylindrical guide comprising a third hole, the cylindrical guide comprising an annular protrusion along an opening of the third hole, the annular protrusion being inserted in the third insert hole to define a third processing space, the annular protrusion being provided on an opposed surface opposed to the blank, a height of the annular protrusion from the opposed surface being larger than at least a height of a surrounding wall of the blank;
- and
- a third punch fitted in the third hole and comprising:
- a rod-shaped shank;
- a rod-shaped distal end closer to the blank than the rod-shaped shank;
- and
- an inclined frustum portion between the rod-shaped shank and the rod-shaped distal end;
- and
- a fourth cylindrical punch movable to and away from the third processing space, the fourth cylindrical punch being configured to clamp the blank between the third punch and the fourth cylindrical punch so as to define a through hole in the blank;
- a transfer mechanism configured to transfer the blank between adjacent two forging die assemblies among the first forging die assembly, the second forging die assembly, and the third forging die assembly;
- and
- a controller configured to control the first forging die assembly, the second forging die assembly, the third forging die assembly, and the transfer mechanism to operate, the controller being configured to clamp the blank in the first processing space between the first pin, the first cylindrical insert, and the first punch so as to press the blank forced in the first hole of the first cylindrical insert using a first end portion of the first pin to provide a pilot portion on the blank, and so as to provide the blank forced in the first surrounding groove with the surrounding wall surrounding the pilot portion, the controller being configured to clamp the blank in the second processing space between the second cylindrical insert and the second punch so as to incline the surrounding wall inserted in the second surrounding groove toward the pilot portion, the controller being configured to clamp the blank in the third processing space between the cylindrical guide, the third punch, and the fourth cylindrical punch so as to provide the through hole in the blank and incline the pilot portion toward the surrounding wall.