Abstract: Seam welding is performed by clamping a coupling portion of an upper sash with a first roller electrode and a second roller electrode, and applying electricity while rotating first roller electrode and the second roller electrode. The first roller electrode includes a plurality of first projecting portions and second projecting portions that are at intervals in a circumferential direction around a first rotational center. The second roller electrode may include a plurality of first opposing projecting portions and second opposing projecting portions that are at intervals in a circumferential direction around a second rotational center, by clamping a coupling portion of an upper sash and applying electricity while rotating.

Abstract: Seam welding is performed by clamping a coupling portion of an upper sash with a first roller electrode and a second roller electrode, and applying electricity while rotating first roller electrode and the second roller electrode. The first roller electrode includes a plurality of first projecting portions and second projecting portions that are at intervals in a circumferential direction around a first rotational center. The second roller electrode may include a plurality of first opposing projecting portions and second opposing projecting portions that are at intervals in a circumferential direction around a second rotational center, by clamping a coupling portion of an upper sash and applying electricity while rotating.

Abstract: A joined body of dissimilar aluminum alloy materials includes a first Al—Mg—Si aluminum alloy material, a second Al—Mg—Si aluminum alloy material, and a single Al—Mg aluminum alloy material. The joined body of dissimilar aluminum alloy materials is formed by welding the first Al—Mg—Si aluminum alloy material and the second Al—Mg—Si aluminum alloy material to the single Al—Mg aluminum alloy material. The Al—Mg aluminum alloy material and the first Al—Mg—Si aluminum alloy material are joined by arc welding. The Al—Mg aluminum alloy material and the second Al—Mg—Si aluminum alloy material are joined by friction-stir welding.

Abstract: A door frame is provided with a first fixed portion and a second fixed portion to which one end and the other end of a beltline reinforcement, with respect to the lengthwise direction thereof, are fixed, respectively; the first fixed portion is provided with a lengthwise-direction position limit portion which is positioned on an extension of the beltline reinforcement in the lengthwise direction thereof and faces against the one end of the beltline reinforcement, the second fixed portion is provided with a thickness directional position limit portion which overlaps the other end of the beltline reinforcement in the door thickness direction, and the lengthwise-direction position limit portion and the thickness directional position limit portion are fixed to the corresponding ends of the beltline reinforcement by welding.

Abstract: A smoothing method and a smoothing apparatus has been achieved, which make it possible to automate smoothing of welded members that was formerly carried out manually. The method according to the present invention uses a belt grinding apparatus, which includes an endless grinding belt and a press pad that presses the grinding belt against a welded area, and uses this belt grinding apparatus in two different modes after obtaining information on heights of surfaces of two welded members along a weld bead of the two welded members. The first mode corresponds to a bead removing step in which the grinding belt is pressed against a welded area by the press pad to reduce the height of the weld bead. At this time, the grinding belt is made to run at a fixed position, while the press pad is made to move toward and away from the welded area (the surface thereof).

Abstract: Provided is a door sash having a vertical pillar sash for vehicle that does not cause a problem of blowout when the vertical pillar sash is formed by welding a plurality of steel sheets. A vehicle door sash is characterized by having a vertical pillar sash and including an inner member and an outer member, on which overlapped portions are respectively formed to thereby form a pocket-like portion. One of the inner member and the outer member includes a bent portion which is continuous with associated the overlapped portion. At least part of a sheet-thickness end face of the other of the inner member and the outer member is in contact with the bent portion, and the bent portion and the sheet-thickness end face are laser-welded at the contact portion.

Abstract: When a formed product having undergone roll forming and welding is bent in the shape of a door sash, the formed product may distort and/or deform. Such distortion and/or deformation is reduced to a sufficient degree. A door sash is formed by bending an elongated metal plate in a widthwise direction such that portions thereof are superimposed, which are welded together for unification. The door sash has a joint portion extending in a longitudinal direction and having exposed surfaces extending continuously in the widthwise direction, a pocket portion extending continuously from one widthwise end of the joint portion and being to be located on the inner side of a vehicle, and a design portion extending continuously from the other widthwise end of the joint portion and being to be located on the outer side of the vehicle. The door sash is bent in the longitudinal direction, and has two parallel welding marks formed on each of the exposed surfaces of the joint portion and extending in the longitudinal direction.

Abstract: A joined body of dissimilar aluminum alloy materials includes a first Al—Mg—Si aluminum alloy material, a second Al—Mg—Si aluminum alloy material, and a single Al—Mg aluminum alloy material. The joined body of dissimilar aluminum alloy materials is formed by welding the first Al—Mg—Si aluminum alloy material and the second Al—Mg—Si aluminum alloy material to the single Al—Mg aluminum alloy material. The Al—Mg aluminum alloy material and the first Al—Mg—Si aluminum alloy material are joined by arc welding. The Al—Mg aluminum alloy material and the second Al—Mg—Si aluminum alloy material are joined by friction-stir welding.

Abstract: A door frame is provided with a first fixed portion and a second fixed portion to which one end and the other end of a beltline reinforcement, with respect to the lengthwise direction thereof, are fixed, respectively; the first fixed portion is provided with a lengthwise-direction position limit portion which is positioned on an extension of the beltline reinforcement in the lengthwise direction thereof and faces against the one end of the beltline reinforcement, the second fixed portion is provided with a thickness directional position limit portion which overlaps the other end of the beltline reinforcement in the door thickness direction, and the lengthwise-direction position limit portion and the thickness directional position limit portion are fixed to the corresponding ends of the beltline reinforcement by welding.

Abstract: A method of bending a long member includes applying a tensile force to the long member to draw out the long member in a lengthwise direction thereof, measuring a displacement of the long member after commencement of the application of the initial tensile force, and bending the long member by applying a correction tensile force and a bending pressure for bending the long member into a curved shape in the lengthwise direction simultaneously to the long member upon the displacement exceeding a predetermined tensile fracture threshold value within a predetermined period of time or after a lapse of the predetermined period of time without the displacement exceeding the tensile fracture threshold value. The correction tensile force is smaller than the tensile force at the time the displacement exceeds the tensile fracture threshold value or the tensile force at the lapse of the predetermined period of time.

Abstract: A smoothing method and a smoothing apparatus uses a belt grinding apparatus, including an endless grinding belt and a press pad that presses the grinding belt against a welded area, and uses this belt grinding apparatus in two different modes after obtaining information on heights of surfaces of two welded members along a weld bead of the two welded members. The first mode corresponds to a bead removing step in which the grinding belt is pressed against a welded area by the press pad to reduce the height of the weld bead. The next mode corresponds to a smoothing step in which the grinding belt presses against the welded area by the press pad while being made to move along the surfaces of the two welded members to smooth the welded area.

Abstract: A door frame structure of a vehicle door which includes an upright pillar sash and an upper sash, wherein joining end surfaces of the upright pillar sash and the upper sash are welded together along a periphery thereof, at least one of the upright pillar sash and the upper sash includes a frame body portion and a cantilever protrusion, the joining end surface of the one of the upright pillar sash and the upper sash partly including the frame body portion and the cantilever protrusion. The upright pillar sash and the upper sash are welded to each other along the frame body portion and a base portion of the cantilever protrusion which is connected to the frame body portion. A leading end portion of the cantilever protrusion which is positioned on the leading end side is not welded.

Abstract: A method of spot-welding portions of a plated steel sheet and a raw steel sheet which are overlaid on each other, the spot-welding method includes preparing a flat electrode and a radius electrode serving as a pair of welding electrodes, bringing the flat electrode and the radius electrode into contact with the portions of the plated steel sheet and the raw steel sheet, respectively, with the portions of the plated steel sheet and the raw steel sheet overlaid on each other, and performing a spot-welding process by passing a welding current through the flat electrode and the radius electrode to spot-weld the portions of the plated steel sheet and the raw steel sheet to each other while applying pressure on the portions of the plated steel sheet and the raw steel sheet by the flat electrode and the radius electrode.

Abstract: When a formed product having undergone roll forming and welding is bent in the shape of a door sash, the formed product may distort and/or deform. Such distortion and/or deformation is reduced to a sufficient degree. A door sash is formed by bending an elongated metal plate in a widthwise direction such that portions thereof are superimposed, which are welded together for unification. The door sash has a joint portion extending in a longitudinal direction and having exposed surfaces extending continuously in the widthwise direction, a pocket portion extending continuously from one widthwise end of the joint portion and being to be located on the inner side of a vehicle, and a design portion extending continuously from the other widthwise end of the joint portion and being to be located on the outer side of the vehicle. The door sash is bent in the longitudinal direction, and has two parallel welding marks formed on each of the exposed surfaces of the joint portion and extending in the longitudinal direction.

Abstract: A door frame structure of a vehicle door which includes an upright pillar sash and an upper sash, wherein joining end surfaces of the upright pillar sash and the upper sash are welded together along a periphery thereof, at least one of the upright pillar sash and the upper sash includes a frame body portion and a cantilever protrusion, the joining end surface of the one of the upright pillar sash and the upper sash partly including the frame body portion and the cantilever protrusion. The upright pillar sash and the upper sash are welded to each other along the frame body portion and a base portion of the cantilever protrusion which is connected to the frame body portion. A leading end portion of the cantilever protrusion which is positioned on the leading end side is not welded.

Abstract: A vehicle door frame structure has an upper sash member located along a roof panel of a vehicle body and also has a vertical pillar sash member located along a center pillar of the vehicle body. The upper sash member has, at its linear end joined to the vertical pillar sash member side, an aesthetically designed section and an inner frame portion. The aesthetically designed section is located on the outer side of the door, and the inner frame portion is located closer to the vehicle interior than the aesthetically designed section and is shorter in length than the aesthetically designed section. The vertical pillar sash member has at its upper end a superposed contact section that is superposed, in the direction of the thickness of the door, on an end of the inner frame portion of the upper sash member, and the superposed contact section and the inner frame portion are joined together while being superposed on each other.

Abstract: A vehicle door frame structure has an upper sash member located along a roof panel of a vehicle body and also has a vertical pillar sash member located along a center pillar of the vehicle body. The upper sash member has, at its linear end joined to the vertical pillar sash member side, an aesthetically designed section and an inner frame portion. The aesthetically designed section is located on the outer side of the door, and the inner frame portion is located closer to the vehicle interior than the aesthetically designed section and is shorter in length than the aesthetically designed section. The vertical pillar sash member has at its upper end a superposed contact section that is superposed, in the direction of the thickness of the door, on an end of the inner frame portion of the upper sash member, and the superposed contact section and the inner frame portion are joined together while being superposed on each other.