Abstract: Method and apparatus are disclosed wherein a hydroformed part remains in a hydroforming die cavity under hydroforming pressure while an attachable fastener nut is operated to pierce and form a collar in the part by forced insertion of the nut into the part and wherein the nut is fastened to the collar by friction welding, friction skip welding or mechanical locking depending on the form of the fastener nut.

Abstract: A fastener nut for hydroformed parts comprises a nut body for receiving a threaded fastener and a locking ring with depending fingers that is received on the nut body. The nut body is adapted to pierce and then form a collar thereabout in a hydroformed part while the part remains in a die cavity under hydroforming pressure. The nut body and the collar formed thereby have a configuration that prevents turning of the locking ring while permitting turning of the nut body relative to the locking ring on full insertion of the nut in the collar, and a cam surface on the nut body that on partial turning of the nut body then forces the locking ring into locking engagement with the collar to thereby attach the fastener nut to the hydroformed part.

Abstract: An in-die hydropiercing device comprises a punch with an annular shearing blade which is operated by a hydraulic cylinder and is received in a ring-shaped die button mounted in one of the dies that form a die cavity for the hydroforming of a part, a center support member that is received in the center of the punch and supports the wall of the part inward of the shearing blade during the hydroforming of the part and also during the piercing of the part with the shearing blade, a slug collector, and a slug retainer that is mounted on the center support member and provides for retention of a slug produced from the piercing operation against the center support member and later releases the slug onto the slug collector for disposal following the opening of the dies and insertion of the slug collector between the open dies and then retraction of the slug collector with the slug for slug disposal.

Abstract: A hydrotapping power unit is disclosed that is operable to hold a hydrotapping tool in a home position adjacent a part while the latter is being hydroformed in a die cavity, to then advance the tool to pierce a hole in the hydroformed part while the part remains in the die cavity and under pressure and then continue to advance the tool to inwardly extrude the part about the hole, to then further advance while also rotating the tool at a feed rate equal to the thread pitch of the tool to thereby form a thread in the pierced hole, and finally retract while also rotating the tool but in the reverse direction and at the same feed rate to release the tool from the threaded hole.

Abstract: Method and apparatus are disclosed wherein a required threaded hole is formed in a hydroformed part with a single tool while the part remains in a hydroforming die cavity. In forming the threaded hole, a hole is first pierced in the wall of the part and then an annular region of the part extending about the hole is extruded inwardly to form an integral tubular neck defining a hole of predetermined depth. The hole is then expanded in a sizing operation to a diameter determined by the required thread to be formed therein by material displacement and the required thread is then formed in the wall of the hole in a material displacing manner.

Abstract: Method and apparatus for forming unobstructed holes in a hydroformed metal part employs a punch having a peripheral side conforming to the desired hole shape and an end face having a central cutting edge with a high point that contacts on closure of a hydroforming die with an unsupported wall section of the part initiating a stress riser therein. During forming of the part, the hydraulic pressure forces the above wall section outward against this high point increasing the magnitude of the stress riser. The punch is advanced while maintaining the hydraulic pressure causing the above high point to fracture this wall section at the stress riser and the above cutting edge to then split and cut this wall section to form oppositely facing cut edges in this section. Simultaneously, oppositely angled cutting edges at opposite ends of the central cutting edge and at the punch end face periphery then cut this wall section in directions away from the oppositely facing cut edges to form oppositely extending slugs.

Abstract: A tubular member is manufactured in a hydroforming and hydroshearing apparatus. A substantially right circular cylindrical workpiece is placed in a die and pressurized to hydroform a substantially rectangular tubular product. The workpiece is presheared during the pressurization period and is fully sheared during the withdrawal of a plurality of plunger members while the internal pressure is maintained. The plunger members are positioned in the die by respective power cylinders which control the withdrawal thereof.