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: 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: 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: 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 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: 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 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: 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: 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: 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: 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: 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 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: 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: 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: 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 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.