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 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, the second metallic material having a first penetrating part larger in diameter or width than the first projection, the first projection being positioned in the first penetrating part; and a different type of material 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 different type of material having a second penetrating part larger in diameter or width than the first projection, the rim of the second penetrating part being spaced radially or widthwise from the first projection by a first gap.

Abstract: A joint structure includes: a first same-type metal member; a second same-type metal member that can be mutually welded with the first same-type metal member; and a different-type member that has a penetrating portion, is interposed between the first same-type metal member and the second same-type metal member. In the plate thickness direction of an emission region in which a laser beam is emitted toward the penetrating portion, the plate thickness at the emission region of the first same-type metal member positioned on the side on which the laser beam is emitted is a predetermined thickness corresponding to a first gap. The first same-type metal member and the second same-type metal member are fused and bonded together via the penetrating portion, and the different-type member is compressed and fixed, such that the different-type member is fixed to the first same-type metal member and the second same-type metal member.

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 welder alternately repeats a short circuit period in which a wire and a welding object are short-circuited and an arc period in which an arc occurs between the wire and the welding object. The arc welder includes a welding output section, a joint type setting section, a storage section, and a waveform parameter determining section. The welding output section performs welding output, and the joint type setting section sets a joint type. The storage section stores a plurality of combinations of joint types and waveform parameters. The waveform parameter determining section determines a waveform parameter based on the joint type set by the joint type setting section and the plurality of combinations. The welding output section performs welding output based on the waveform parameter determined by the waveform parameter determining section. Thus, vaporized zinc is easily released and sufficient welding is performed.

Abstract: As a conventional problem, welding on surface-treated material, such as a zinc-coated steel plate, considerably generates air holes including blowholes and also generates lots of spatters. Present invention provides a method of controlling arc welding performed in a manner that a short-circuit period, in which a short circuit is generated between a welding wire and an object to be welded, and an arc period, in which an arc is generated after release of the short circuit, are repeated alternately. According to the method, welding current is increased from an arc-regeneration-before current to a first welding current at a detection of release of the short circuit such that an increase gradient of the welding current becomes not less than 750 A/msec. This suppresses generation of air holes and spatters in welding work on a surface-treated material, such as a zinc-coated steel plate.

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: Disclosed is a method for controlling arc welding where an arc is generated between a welding wire as a consumable electrode and an object to be welded. The method includes: keeping a wire feed speed at a predetermined constant speed in a steady-state welding period; and at a time point when welding termination is ordered, either switching the wire feed speed from the predetermined constant speed to a wire feed speed at which the welding wire is fed in alternating forward and backward directions, or decreasing the wire feed speed from the predetermined constant speed with time, and then switching the wire feed speed to the wire feed speed at which the welding wire is fed in alternating forward and backward directions at a time point when a predetermined time period has passed since when welding termination was ordered.

Abstract: In arc welding, determining a current value to be high in an early stage of the arc period is effective in reducing spatters caused by feeble short circuit in the arc period. In that case, to sharply decrease the voltage that has increased with increase in current, an inductance value of a reactor has to be kept small. However, a small inductance value causes a problem—weakness against disturbance. The present invention provides an arc welding control method that performs arc welding while repeating the short-circuit period and the arc period. According to the method, changing an inductance value relating to welding output in the arc period offers stable arc welding with fewer spatters and insusceptibility to disturbance.

Abstract: A lap-joined structure including at least one similar metallic material weldable to each other and a different material different in type from the at least one similar metallic material and difficult to be welded to the similar metallic material. The different material is sandwiched and fixed between the similar metallic material. The similar metallic material has at least one exhaust hole or exhaust groove around the weld zone where the similar metallic material is melted and joined together. The exhaust hole or exhaust groove extends through the similar metallic material along its thickness. Thus, the similar metallic material and the different material are fixed and joined together.

Abstract: A laser welding method of the present disclosure includes the step of irradiating a workpiece with a laser beam in a helical shape along a weld part of the workpiece. The helical shape is a combination of a circular trajectory in which a laser beam is moved circularly, and a movement trajectory in which the laser beam is moved in a proceeding direction along the weld part. Furthermore, first energy of the laser beam moving so as to have a component of the proceeding direction in the circular trajectory is larger than second energy of the laser beam moving so as to have a component of an opposite direction to the proceeding direction in the circular trajectory.

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: Disclosed is a method for controlling arc welding where an arc is generated between a welding wire as a consumable electrode and an object to be welded. The method includes: keeping a wire feed speed at a predetermined constant speed in a steady-state welding period; and at a time point when welding termination is ordered, either switching the wire feed speed from the predetermined constant speed to a wire feed speed at which the welding wire is fed in alternating forward and backward directions, or decreasing the wire feed speed from the predetermined constant speed with time, and then switching the wire feed speed to the wire feed speed at which the welding wire is fed in alternating forward and backward directions at a time point when a predetermined time period has passed since when welding termination was ordered.

Abstract: A junction structure includes a first metallic material, a second material different in type from the first metallic material, and a welding wire as a third material similar to the first metallic material. The second material is stacked on the first material. The molten metal of the third metallic material is deposited by arc welding into the through part of the second material so as to form a flanged or tapered bead, so that the first and third metallic materials and the second material are fixed together.

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: An arc welding device includes memory in which a combination of a short circuit frequency, a peak current, and a peak current period is stored and determinator that determines a peak current and a peak current period based on a set short circuit frequency and the combination stored in memory. A welding output part performs welding output based on the peak current and the peak current period determined by determinator.

Abstract: To provide a compact welding torch in which a motor can be easily replaced, in which, when a motor capable of high-speed welding is used for a long time in a high current region, heat generated by the motor can be sufficiently cooled, and in which the motor can be protected from spatters or the like. A first cooler that cools a first side surface of a motor parallel to a shaft of the motor and a second cooler that cools a second side surface of the motor different from the first side surface are included. The first cooler has a first inflow port and a first outflow port for a cooling fluid, and a first flow passage that connects the first inflow port and the first outflow port. The second cooler has a second inflow port and a second outflow port for the cooling fluid, and a second flow passage that connects the second inflow port and the second outflow port.

Abstract: A method of controlling arc welding with a consumable electrode includes repeating the following periods in sequence: a short-circuit welding period to perform short-circuit arc welding; a pulse welding period to perform pulse welding; and a cooling period in which the welding current output is zero.

Abstract: A laser welding method of the present disclosure has a first step and a second step. In the first step, a first workpiece and a second workpiece are overlaid in a first machining region. In the second step, the first workpiece and the second workpiece are irradiated with laser beam in the first machining region while the laser beam is moved in a spiral path. Moreover, in the second step, the first workpiece and the second workpiece are melted by irradiation of the laser beam to form a liquid phase portion. Furthermore, in the second step, the laser beam is moved so that the liquid phase portion is not irradiated with the laser beam again.