Abstract: A laser welding device includes a welding head configured to emit a laser beam to a working point, a shield gas supplying nozzle configured to supply shield gas to the working point, and a high-speed air supplying nozzle configured to supply a high-speed air stream between the shield gas supplying nozzle and the welding head, the high-speed air stream having a flow rate that is larger than a flow rate of the shield gas, and being supplied in a horizontal direction directly above the shield gas supplied to the working point, or in a direction orthogonal to an emission direction of the laser beam. The high-speed air supplying nozzle is disposed in a range from 80 mm to 200 mm, both inclusive, above the working point, or in a range equal to or lower than a half of a working distance between an emission surface of the laser beam of the welding head and the working point, and supplies the high-speed air stream in a belt shape.

Abstract: A joint structure includes a first metallic material having a first projection, a second metallic material similar in type to the first metallic material and weldable to the first metallic material, and a different type of material having a first penetrating part and sandwiched between the first metallic material and the second metallic material, the different type of material being different in type from the first metallic material and the second metallic material and difficult to be welded to the first metallic material and the second metallic material. The first projection is smaller in diameter or width than the first penetrating part and is spaced from the rim of the first penetrating part by a first gap. The first projection is positioned in the first penetrating part and is spaced from the second metallic material by a second gap in the thickness direction of the first penetrating part.

Abstract: In thin sheet welding, when a heat input amount relative to a sheet thickness is too large, a welding defect such as a deviation from aim due to occurrence of a strain or burn through may easily occur. When a welding current is decreased to reduce the heat input amount, there is an issue in which an arc tends to become unstable. In arc welding in which short-circuit and arcing are repeated, first heat input period (Th) and second heat input period (Tc) having a heat input amount less than that of first heat input period (Th) are periodically repeated and a welding current during an arc period in second heat input period (Tc) is decreased to extinguish the arc. This reduces the heat input amount into a welding object and suppresses burn through or a strain upon welding, while making the arc stable.

Abstract: A laser welding method according to the present disclosure includes a step in which a third material is interposed between a first material and a second material, which are made of the same type of metal so as to be weldable to one another, and at least one of which is provided with a protruding portion, wherein the third material is difficult to weld to the first material and the second material and has a through-hole portion into which the protruding portion is inserted. The method also includes a step in which, when the third material is interposed between the first material and the second material, a region corresponding to the protruding portion is irradiated with a laser beam from the first material side, and the first material and the second material are welded via the through-hole portion.

Abstract: In thin sheet welding, when a heat input amount relative to a sheet thickness is too large, a welding defect such as a deviation from aim due to occurrence of a strain or burn through may easily occur. When a welding current is decreased to reduce the heat input amount, there is an issue in which an arc tends to become unstable. In arc welding that repeats short-circuit and arcing, first heat input period (Th) and second heat input period (Tc) having a heat input amount less than that of first heat input period (Th) are periodically repeated. This reduces the heat input amount into a welding object and suppresses burn through and a strain upon welding while making the arc stable.

Abstract: A method for determining a laser welding condition of the present disclosure includes a first step, a second step, and a third step. In the first step, workpiece information indicating characteristics of a workpiece is input. In the second step, laser information indicating characteristics of laser light is input. In the third step, a first welding condition is calculated based on the workpiece information and the laser information, and then displayed. The first welding condition is any one of a recommended laser power of the laser light, a recommended welding speed, a recommended welding pattern, an estimated strength of a welded portion, and an estimated weld depth of the welded portion. Furthermore, the workpiece information includes a joint shape of the workpiece. Thus, an optimum weld condition can be set while considering a shape of a joint in welding.

Abstract: A joint structure includes a first material (1), a second material (2) weldable to the first material, and a third material (3) at least a portion of which being sandwiched between the first material and the second material, having a through opening portion at the sandwiched portion, and including a material that is difficult to be welded to both the first material and the second material, the first material and the second material welded the via through opening portion. At least one of the first material and the second material is provided with a protrusion (14) inserted in the through opening portion. A first gap (4) is provided between an inner peripheral surface of the through opening portion and the protrusion. A second gap (5) is provided between the first material and the second material, the second gap having a size depending on a plate thickness of the first material in a region corresponding to the protrusion. Under a condition in which the second gap has a size of greater than or equal to 0.

Abstract: A method of welding surface-treated members together using a welding wire includes a step of transferring a droplet detached from the wire to the members; and a step of pushing the melt pool in the direction opposite to the direction of welding in such a manner that the gas generated from the members during welding is released from the site of generation. The melt pool is pushed to expose the overlapped region of these members. The gas generated from the members is released to the exposed portion, preventing generation of pores such as blowholes, and also generation of spatters.

Abstract: A laser welding method of the present disclosure includes a first step, a second step, and a third step. In the first step, a first workpiece and a second workpiece are stacked on each other. Each of the first workpiece and the second workpiece has a surface coated with a first material and is made of a second material, which is different from the first material. In the second step, a first region in which the first workpiece and the second workpiece are stacked on each other is irradiated with a laser beam so that the laser beam penetrates both the first workpiece and the second workpiece. In the third step, a second region including the first region is irradiated with a laser beam in a spiral fashion.

Abstract: The laser welding method according to the present disclosure has a first step for forming a weld bead by irradiating an object to be welded with a laser beam along a first helical trajectory around a first center of rotation moving in a welding direction, and a second step for irradiating the object to be welded with a laser beam along a second helical trajectory around a second center of rotation moving in the welding direction. A diameter of rotation of the laser beam in the first step is larger than a diameter of rotation of the laser beam in the second step.

Abstract: A base material is welded by a first welding method in a case where a welding parameter related to heat input to the base material is less than a first threshold value. The base material is welded by a second welding method in a case where the welding parameter is less than a second threshold value and is more than the first threshold value. The base material is welded by a third welding method in a case where the welding parameter is more than the second threshold value. By adjusting welding conditions regardless of the thickness of the base material, a welding method suitable for the thickness of the base material is determined to provide a welding with little spatter and no meltdown of the base material.

Abstract: A welding target is irradiated with a laser beam so as to form a beam spot that moves relatively with respect to the welding target along a locus having a spiral shape rotating around a rotation center moving in a welding direction. The welding target is welded using the laser beam irradiated with. While the welding target is irradiated with the laser beam, the welding target is irradiated with the laser beam based on an interval coefficient which is a value indicating an overlapping degree of the locus having the spiral shape in the welding direction.

Abstract: A laser welding control method according to the present disclosure includes: a first step of causing a first steel plate having a protrusion and a second steel plate to overlap so that a tip of the protrusion provided on the first steel plate makes contact with the second steel plate; and a second step of irradiating the protrusion with laser light in an irradiation pattern having a size larger than a size of the protrusion in plan view after the first step. At least one of a surface of the first steel plate that faces the second steel plate and a surface of the second steel plate that faces the first steel plate is plated.

Abstract: In controlling an arc welding of consumable electrode type in which pulse welding and short-circuit welding alternately repeat, forward feeding and backward feeding of a welding electrode periodically repeat in a short-circuit welding period. The forward feeding of the welding electrode starts when a welding current is smaller than a base current immediately before a pulse period ends.

Abstract: An arc-welding method in welding by repeating a short circuit and an arc. When the sign of opening of the short circuit is detected, the welding current is reduced from a first current value at the detection of the sign to a second current value, which is lower than the first current value. When the opening of the short circuit is detected, a pulse current having a peak value higher than the first current value is supplied at a plurality of times in the arc period. This suppresses porosities and spatters when galvanized steel sheets are welded.

Abstract: An arc-welding method in welding by repeating a short circuit and an arc. When the sign of opening of the short circuit is detected, the welding current is reduced from a first current value at the detection of the sign to a second current value, which is lower than the first current value. When the opening of the short circuit is detected, a pulse current having a peak value higher than the first current value is supplied at a plurality of times in the arc period. This suppresses porosities and spatters when galvanized steel sheets are welded.

Abstract: In control applying a gradient to a command voltage value during an arc period, although stable welding can be performed even in a case where a protrusion length of a welding wire becomes long, when the disturbance such as sudden change in the protrusion length is generated, a current waveform of the arc period is undershot, the short circuit period is disturbed, and it took time to return to the stable state, and the amount of sputter generation is also increased. Therefore, it is possible to suppress a change in current such as undershoot or the like when the disturbance is generated, stabilize short circuit cycle, perform welding with a strong resistance to disturbance and a small amount of sputter generation by changing an inductance value a plurality of times during the arc period.

Abstract: In a consumable electrode-type arc welding in which pulse welding and short-circuit welding are alternately repeated, a welding current is controlled such that a welding current immediately before shifting from the pulse welding to the short-circuit welding is lower than a base current in a pulse.

Abstract: A laser machining system includes a laser oscillator, a laser machining head, and a reflection unit. The laser oscillator outputs laser light. The laser machining head, which includes a first optical member for collecting the laser light, emits the collected laser light. The reflection unit, which includes a reflective member for reflecting the laser light emitted from the laser machining head, radiates the reflected laser light onto a work.

Abstract: A laser welding method of the present disclosure includes a first step and a second step. In the first step, a first end of a first workpiece is positioned such that the first end of the first workpiece is overlapped on a second end of a second workpiece to form a corner joint. In the second step, the first end forming the corner joint is irradiated from above with a laser beam. Additionally, the first end is positioned to protrude relative to the second workpiece in the first step.