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.

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: 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: An arc welding method preforms reciprocating wire feed so as to alternately perform forward feed and reverse feed. The arc welding method includes a normal arc welding step, a normal short circuit welding step, and an abnormal arc welding step. In the abnormal arc welding step, a short circuit state occurs at a second time point, which is before a lapse of a second period from a first time point at which an arc state occurs. Further, in the abnormal arc welding step, the reciprocating wire feed continues until a third time point after a lapse of a first period from the second time point. At the third time point, the reciprocating wire feed is stopped and the abnormal arc welding step is completed. From the third time point, the welding wire is decelerated and the reciprocating wire feed is restarted.

Abstract: A laser welding method according to the present disclosure includes a coupling forming step and a welding step. In the coupling forming step, a T coupling is formed by superimposing a side surface of a first member and a lower surface of a second member on each other. In the welding step, an upper surface of the second member opposite to the lower surface is irradiated with a laser beam so that the first member and the second member are welded to each other by the laser beam. Moreover, in the welding step, the laser beam is moved in a direction along the side surface of the first member while being weaved.

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 method to determine welding conditions includes relational expressions or tables about various parameters for setting welding conditions. The method can determine and display the recommended values for the welding conditions which are suitable for the information about the object to be welded and the information about the welding method set by the operator. The welding conditions include a welding current, a welding voltage, a wire feed speed, a welding speed, and a leg length. Furthermore, if the operator changes the recommended value for a welding condition to a new value, the method can determine new recommended values for the other welding conditions compatible with the new value and display the new recommended values.

Abstract: In an arc welding control method of repeating a short circuit and an arc to perform welding, control is carried out to conduct a welding current having a first polarity for a short circuit period, and a first commutation to commutate the welding current from the first polarity to be a polarity of the welding current for the short circuit period to a second polarity to be opposite to the first polarity is carried out for an arc period subsequent to the short circuit period. Furthermore, control is performed to carry out a second commutation to commutate the welding current from the second polarity to the first polarity for the arc period in which the first commutation is executed. Consequently, it is possible to reduce an energy input amount to a base metal, thereby suppressing burn-through in welding of a thin plate.

Abstract: A method to determine welding conditions includes relational expressions or tables about various parameters for setting welding conditions. The method can determine and display the recommended values for the welding conditions which are suitable for the information about the object to be welded and the information about the welding method set by the operator. The welding conditions include a welding current, a welding voltage, a wire feed speed, a welding speed, and a leg length. Furthermore, if the operator changes the recommended value for a welding condition to a new value, the method can determine new recommended values for the other welding conditions compatible with the new value and display the new recommended values.

Abstract: An arc welding method comprising the steps of accelerating a feeding speed of a welding wire to cause shorting between the welding wire and a base metal when a welding end signal is input during a period of arcing, retracting the welding wire backward thereafter until a wire retracting speed reaches a predetermined rate, controlling the wire retracting speed constant at this speed for a predetermined duration of time, then stopping the backward retraction of the welding wire, and then terminating a welding power output after supplying a predetermined amount of welding current for a predetermined duration of time starting from a time when opening of the shorting occurs during the backward retraction of the welding wire.

Abstract: A method to determine welding conditions includes relational expressions or tables about various parameters for setting welding conditions. The method can determine and display the recommended values for the welding conditions which are suitable for the information about the object to be welded and the information about the welding method set by the operator. The welding conditions include a welding current, a welding voltage, a wire feed speed, a welding speed, and a leg length. Furthermore, if the operator changes the recommended value for a welding condition to a new value, the method can determine new recommended values for the other welding conditions compatible with the new value and display the new recommended values.

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: An arc welding method relates to consumable electrode arc welding in which a welding wire feeding rate suitable for a welding current is determined as an average feeding rate, and the short circuit state and the arc generation state are alternately generated by changing the wire feeding periodically and repeatedly between the forward feeding and the reverse feeding. The method offers arc welding with the average feeding rate according to a welding current, a predetermined frequency, and a predetermined velocity amplitude. In the method, at least any one of the frequency and the velocity amplitude is set to a value suitable for the welding current.

Abstract: A method for arc welding can control the increase slopes of the short-circuit current and the inflection point of the increase slopes in the welding start period to be smaller than in the steady-state welding period. Thus, the increase slopes of the short-circuit current and the inflection point are made different between the welding start period and the steady-state welding period, thereby reducing sputtering in the welding start period.

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: A welding control method alternately repeats a short circuit period, during which a welding wire and an object to be welded short-circuit, and an arc period, during which an arc is generated and discharged, to weld the object to be welded. The method compares average output voltage, which is an average of welding voltage calculated during welding, to set voltage preliminarily set, and controls a welding output current produced when an arc is generated based on the comparison result therefrom, to regulate the meltage of the wire for adjusting the arc length, which brings the short circuit cycle closer to a constant one when a disturbance (e.g. extended or shortened arc length) occurs.

Abstract: In a method for controlling pulse arc welding where an arc is created between a wire and a base material, a pulse waveform different from the pulse waveform for steady-state welding is outputted when a predetermined time has passed since short-circuit welding control was started at arc start, and after a sufficiently large melt pool is formed, the pulse waveform for the steady-state welding is outputted. This reduces the generation of spatters after an arc is created and until the arc is stabilized.

Abstract: A welding control method for a welding device having an output characteristic with a predetermined gradient showing a relation between a welding output voltage and a welding output current. By setting a set target welding voltage that is higher than the set initial welding voltage according to a difference between the set initial welding voltage and the welding output voltage, the welding output voltage is controlled to be the set target welding voltage. Thus, a proper arc length can be achieved early by correcting the change of the arc length due to, for example, motion of the hands of a welding operator.

Abstract: If a short circuit does not occur during deceleration of a wire feed speed in forward feed of a welding wire before the wire feed speed reaches a predetermined wire feed speed, a cyclic change is stopped and the wire feed speed is constantly controlled at the first feed speed. If a short circuit occurs during forward feed at the first feed speed, deceleration from the first feed speed starts, and the cyclic change is resumed for welding. This achieves uniform weld bead without increasing spatters even if any external disturbance such as change of distance between a tip and base material occurs.