Abstract: A welding tip includes a tip body having a wire insertion bore along a central axis and a leaf spring configured to press a welding wire onto a feeding point disposed on an inner surface of the wire insertion bore. The tip body 1a has an aperture on an outer circumferential surface on the distal end side. The leaf spring has a first end that is a free end disposed on the distal end side of the tip body and a second end fixed to the tip body. The aperture includes a first aperture accommodating the leaf spring and second apertures disposed in communication with the first aperture and configured to discharge wear particles created during welding to the outside.

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: 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 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 pulse arc welding device is controlled so as to weld an object by removing, from a welding wire, a molten droplet produced by melting the welding wire by applying a welding voltage between the welding wire and the object and allowing a welding current to flow through the welding wire such that the welding current alternately repeats, at pulse frequency, a peak current period in which the welding current is a peak current and a base current period in which the welding current is a base current smaller than the peak current. A removal time point at which the molten droplet is removed from the welding wire is determined. In a case where the removal time point is not in the base current period, a pulse waveform parameter which is at least one of the peak current and the peak current period is adjusted, and the pulse frequency based on a predetermined relationship between the pulse frequency and the pulse waveform parameter is adjusted so as to cause the removal time point to be in the base current period.

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: 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: 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: 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 consumable electrode arc welding method includes: setting an optimal voltage and an increasing slope of a short circuit current to correspond to a setting current; feeding a consumable electrode wire; and alternately generating a short circuit condition and an arc condition, thereby carrying out welding, wherein the short circuit current is controlled by changing the increasing slope of the short circuit current according to a difference between the setting voltage and the optimal voltage when the setting voltage is different from the optimal voltage. With this, the increasing slope of the short circuit current and the current value corresponding to the inflection point of the short circuit current are automatically changed.

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: An arc welding method alternately generates a short-circuit state and an arc state. In the method, short circuits are generated also in the arc period. This more than doubles the total number of short circuits, which is the sum of the short circuits generated in the short circuit period and those generated in the arc period. This enables a thin plate to be arc welded at a higher speed, while reducing its burn-through.

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.