Abstract: A method of laser welding where two steel sheets are welded by a laser beam after the two steel sheets are overlapped with a predetermined gap is disclosed. The method includes: a stitch welding step where a laser beam of focal region is irradiated along a welding portion of the upper steel sheet and the lower steel sheet such that a molten slot is formed at the upper steel sheet along the welding portion and an heat expansion portion is formed at the lower steel sheet along the welding portion by thermal conduction; and a pattern welding step where the laser beam of focal region is irradiated along the welding portion with a predetermined pattern such that an edge of the molten slot formed at the upper steel sheet is melted together with the heat expansion portion of the lower steel sheet so as to form a molten pool.

Abstract: A self-piercing rivet is disclosed. The self-piercing rivet integrally joins an upper plate member and a lower plate member overlapped with each other. The self-piercing rivet includes: a head portion; and a shank portion integrally connected to the head portion and provided with more than two slits.

Abstract: The present invention provides a laser welding method for steel sheets. The laser welding method includes irradiating a low heat input laser beam to a weld zone with a uniform welding pattern of a zigzag shape, with a constant pitch, and with a constant welding speed, so that autogenous welding may be achieved without a feed wire, such that cost of material may be reduced and joinability and performance may be improved.

Abstract: A bumper beam assembly for a vehicle may include a bumper beam having a horizontal support plate, front and rear vertical support plates attached to the horizontal support plate, wherein the rear vertical support plate includes an insertion hole, a partition formed along the horizontal support plate between the front and rear vertical support plates, and a stay, an end portion of which may be inserted into the insertion hole.

Abstract: The present invention relates to a notch pressing device for a crash box of a vehicle. The notch pressing device for a crash box of a vehicle includes a lower fixing plate, an upper fixing plate mounted to the lower fixing plate by a plurality of posts, a core rotating unit that selectively rotates a core where the crash box is put and is disposed to one end of the lower fixing plate, a supporting unit that is connected to a moving die for selectively supporting a lower portion of an end of the core and that is disposed to a side of the lower fixing plate, and a forming unit which is connected to a punch, which selectively pushes the crash box put to the core for forming the notch, and that is disposed to the upper fixing plate.

Abstract: A welding device for a stretch bender is disclosed. The welding device for the stretch bender may include: an operating unit adapted to move forward toward or rearward from a bending die for shaping a shaped beam and mounted in front of the bending die; and a welding unit mounted at the operating unit and welding flange portions of the shaped beam that is completely formed by the bending die so as to prevent the flange portions from being overlapped with each other when extracting the shaped beam, the welding unit being movable forward or rearward against the operating unit.

Abstract: A roll forming system and a roll forming method are disclosed. The roll forming system according to an exemplary embodiment of the present invention includes a bending unit provided with synchronizing means moving a synchronizing table in keeping pace with a forming speed of a shaped beam along a process line, clamping means clamping both sides of the shaped beam, position conversion means converting a position of the shaped beam between a cutting position and a bending position, cutting means cutting one side of the shaped beam by a cutting wheel, and a bending means stretch-bending the shaped beam to have a predetermined curvature.

Abstract: A roll forming system which roll-forms a shaped beam by a roll forming unit including a plurality of roll formers is disclosed. A laser welding device for the roll forming system may include: front and rear guide means disposed apart from each other at the rear of the roll forming unit, and guiding movement of the shaped beam; laser welding means mounted above and between the front and rear guide means, reciprocatedly rotating a mirror by controlling a mirror motor so as to irradiate a laser beam to a welding position of the shaped beam, and thereby forming a welding bead having a predetermined welding pattern; forming speed detecting means detecting a forming speed of the shaped beam and transmitting a signal corresponding thereto to a controller; a camera disposed at the rear of the laser welding means, photographing a welding portion of the shaped beam, and transmitting an image signal corresponding thereto to the controller.

Abstract: A bumper beam assembly for a vehicle may include a bumper beam having a horizontal support plate, front and rear vertical support plates attached to the horizontal support plate, wherein the rear vertical support plate includes an insertion hole, a partition formed along the horizontal support plate between the front and rear vertical support plates, and a stay, an end portion of which may be inserted into the insertion hole.

Abstract: The present invention relates to a bending device of which a beam is inserted between laminated moldings formed by slidably layering a plurality of molding plates, and the bending device of which deformation of the laminated moldings may simultaneously realize bending of up and down directions and side directions of a curved portion of a beam, and thus the bending device may realize a 3-dimensional bending process at once.

Abstract: The present invention provides a laser welding method for steel sheets. The laser welding method includes irradiating a low heat input laser beam to a weld zone with a uniform welding pattern of a zigzag shape, with a constant pitch, and with a constant welding speed, so that autogenous welding may be achieved without a feed wire, such that cost of material may be reduced and joinability and performance may be improved.

Abstract: As to the method for fabricating a member of vehicle, after a member for vehicle having high-rigidity of martensite organization is fabricated by a hot stamping forming, the martensite organization is transformated to a ferrite having a low-rigidity partially and improved toughness or to a metal organization heat treated by tempering process through induction heating or secondary heat treatment using laser beam of conduction area, and thereby collision absorption performance is improved by stabilizing the absorption directivity of the collision energy without additional reinforcement.

Abstract: A roll forming apparatus and a method thereof form a composite panel by simultaneously roll forming upper and lower plates with different thicknesses and a zigzag-shaped core panel, and welding them together. A bumper beam is manufactured by using the composite panel.

Abstract: The present invention relates to a laser welding method for galvanized steel sheets where galvanized steel sheets are lap-welded by using a laser beam of a keyhole welding zone in a state in which a gap for exhausting zinc fumes is formed by embossing a plurality of protrusions along a welding line on one galvanized steel sheet among the galvanized steel sheets by using a laser beam of a conducting welding region.

Abstract: A roll forming apparatus and a method thereof form a composite panel by simultaneously roll forming upper and lower plates with different thicknesses and a zigzag-shaped core panel, and welding them together. A bumper beam is manufactured by using the composite panel.

Abstract: A warm hydro-forming device comprises: an upper mold and a lower mold respectively mounted to an upper mold die and a lower mold die; a lifting die installed to the lower mold die through a guide unit, an upper portion of the lifting die being connected to the upper mold die through a lifting unit to cooperatively operate in an upward and downward direction with the upper mold die; a pair of hydraulic pressure cylinders for providing an axial compression force to the tube component and supplying a forming hydraulic fluid into the tube component; an ascending and descending unit for ascending or descending the upper mold die; and a heating unit associated with the lifting die such that the heating unit can move toward or away from the tube component. The heating unit heats the tube component and a forming hydraulic fluid through a high frequency induction heating.

Abstract: Disclosed is an apparatus and method for making an automotive bumper beam by a single roll forming. The apparatus of the present invention comprises an uncoiler; a straightener; a brake press; a first group of roll formers; a second group of roll formers; a final sweep roll former; adjuster; welding member; and cutting member. The method of the present invention is comprising of a step of preparing the steel sheet; a step for forming the tubular cross-sectional shape on the steel sheet; a step for forming a sweep on the steel sheet; a step for adjusting the tubular cross-sectional shape of the steel sheet; a step for welding two flanges to each other at their terminal ends; and a step for cutting the steel sheet to the predetermined length.