Abstract: An arc welding method of the present invention controls a short-circuit current increasing gradient (di/dt), an inflection point at which the short-circuit current increasing gradient (di/dt) changes, the current in a peak period and in a base period, and the time of the peak period in accordance with a difference between a set voltage and an output voltage. This allows the output voltage to be matched with the set voltage, and stabilizes the arc. Thereby, a stable arc welding method can be implemented, even as a method for outputting a welding current based on a welding voltage.

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.

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: 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: 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 control method for carrying out welding by generating an arc between a wire and a base material. The wire is fed at wire feed speed (Wf) of periodically repeating forward feeding and reverse feeding with predetermined frequency and amplitude from time point (100) at which start of the welding is instructed, or from a certain time point (101) after the start of the welding is instructed, and then the wire feed speed is changed to a constant speed. Since the wire feed speed is controlled by periodically repeating forward feeding and reverse feeding at the arc start, short-circuit can be opened regardless of the electromagnetic pinch force, and spatters, which are generated at the early stage of the arc start because a molten pool is not preset, can be reduced.

Abstract: An arc welding control method carries out weld with a welding current and a welding speed different from those at a steady welding period according to intrinsic resistivity of a weld wire or a base material at a welding start period and a welding end period, so as to obtain a satisfactory welding quality.

Abstract: A control method for an arc welding apparatus having a function of prohibiting detection of neck based on a change amount of welding voltage and an arc welding apparatus using the method. Thus, since neck determination can be carried out accurately by preventing wrong detection of neck, it is possible to reduce the occurrence of spatter.

Abstract: Disclosed is a consumable electrode arc welding in which short-circuit welding is performed by alternating short-circuits and arcs while a welding wire is fed automatically. In this method, a short-circuit state and an arc state are alternately generated by feeding the welding wire in periodically alternating forward and backward directions at a predetermined frequency and a predetermined velocity amplitude with reference to a basic wire feed speed based on a set current. The speed of periodic feeding of the welding wire is controlled in such a manner that the waveform to feed the welding wire is different between the forward and backward directions.

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.

Abstract: A welding control unit has a common power section for detecting contact of a welding material and for welding. A material contact detector for detecting contact of the welding material and a workpiece, and a power controller are built in the welding control unit. This stabilizes a bead shape in starting welding. The number of components can also be reduced, resulting in more inexpensive equipment. In addition, only a space for installing the welding control unit is needed without any additional space.

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: 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: 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: An arc welding method of the present invention controls a short-circuit current increasing gradient (di/dt), an inflection point at which the short-circuit current increasing gradient (di/dt) changes, the current in a peak period and in a base period, and the time of the peak period in accordance with a difference between a set voltage and an output voltage. This allows the output voltage to be matched with the set voltage, and stabilizes the arc. Thereby, a stable arc welding method can be implemented, even as a method for outputting a welding current based on a welding voltage.

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: 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: An arc welding control method for carrying out welding by generating an arc between a wire and a base material. The wire is fed at wire feed speed (Wf) of periodically repeating forward feeding and reverse feeding with predetermined frequency and amplitude from time point (100) at which start of the welding is instructed, or from a certain time point (101) after the start of the welding is instructed, and then the wire feed speed is changed to a constant speed. Since the wire feed speed is controlled by periodically repeating forward feeding and reverse feeding at the arc start, short-circuit can be opened regardless of the electromagnetic pinch force, and spatters, which are generated at the early stage of the arc start because a molten pool is not preset, can be reduced.

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.