Pulse arc welding apparatus and pulse arc welding method

Abstract

To suppress deterioration in welding quality due to magnetic blow when welding is performed by generating each arc on a common workpiece by a plurality of pulse arc welding power supplies.SOLUTION: In a pulse arc-welding device provided with a plurality of pulse arc-welding power sources PS1, PS2 for generating arcs 31, 32 by feeding weld wires 11, 12 to weld, the pulse arc-welding power sources PS1, PS2 have a normal weld mode and a magnetic blow countermeasure mode, and when the plurality of pulse arc-welding power sources PS1, PS2 generate the arcs 31, 32 to weld a common workpiece 2, the pulse arc-welding power sources PS1, PS2 are switched to the magnetic blow countermeasure mode to weld.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a pulse arc welding apparatus and a pulse arc welding method. [Background technology]

[0002] Consumable electrode pulsed arc welding (CPAW) is used for welding steel and other materials. In this consumable electrode pulsed arc welding process, a welding wire is fed, and a rising transition current (rising from a base current to a peak current) is applied during the peak rise period, the peak current is applied during the peak period, a falling transition current (declining from the peak current to a base current) is applied during the peak fall period, and the base current is applied during the base period. These welding currents are repeated as one pulse cycle to perform welding. Furthermore, the arc length is maintained at an appropriate value by feedback-controlling the peak current, peak period, or pulse period so that the average welding voltage is equal to the welding voltage setting. In pulsed arc welding, one droplet is transferred per pulse period, resulting in stable droplet transfer, which minimizes spatter and produces a beautiful bead.

[0003] In consumable electrode pulsed arc welding, a magnetic field is formed around the arc due to the welding current flowing through the arc and workpiece, and the arc may be deflected by the force of this magnetic field. This condition is generally referred to as magnetic arc blow. In consumable electrode pulsed arc welding, the base current value is small, so the arc is easily deflected when it receives a biased force from the magnetic field, easily causing magnetic arc blow. Therefore, in consumable electrode pulsed arc welding, arc deflection due to magnetic arc blow is likely to occur during the base period. When magnetic arc blow occurs, the arc deflects, resulting in poor welding quality. Furthermore, if the arc deflection becomes too large, arc interruption may occur, resulting in welding defects. Therefore, measures to prevent magnetic arc blow are important for achieving good welding quality.

[0004] Various countermeasures against magnetic arc blow have been proposed in consumable electrode pulsed arc welding. A typical example is a method in which, when magnetic arc blow is detected, the base current is increased to strengthen the rigidity of the arc, thereby suppressing arc deflection (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 4319432 Summary of the Invention [Problem to be solved by the invention]

[0006] When multiple pulse arc welding power sources are used to generate arcs on a common workpiece, magnetic arc blow is likely to occur due to the influence of the magnetic fields formed by the welding currents output from each pulse arc welding power source. In such cases, even if conventional countermeasures against magnetic arc blow are implemented, it has not been possible to prevent deterioration in welding quality due to magnetic arc blow.

[0007] Therefore, an object of the present invention is to provide a pulse arc welding device and a pulse arc welding method that can suppress deterioration of welding quality due to magnetic arc blow, for example, when multiple pulse arc welding power sources are used to generate arcs on a common workpiece for welding. [Means for solving the problem]

[0008] A pulse arc welding apparatus provided by a first aspect of the present invention is a pulse arc welding apparatus including a plurality of pulse arc welding power sources that feed a welding wire to generate an arc for welding, wherein the pulse arc welding power sources have a normal welding mode and a magnetic arc blow prevention mode, and when the plurality of pulse arc welding power sources each generate an arc to weld a common workpiece, the pulse arc welding power sources are switched to the magnetic arc blow prevention mode to perform welding.

[0009] As an example, the pulse arc welding apparatus of the present invention is characterized in that, in the magnetic arc blow prevention mode, the value of the base current and / or the length of the peak fall period are increased by an increased value compared to in the normal welding mode.

[0010] As an example, the pulse arc welding device of the present invention is characterized in that the increase value is set in accordance with the number of the plurality of pulse arc welding power sources.

[0011] As an example, the pulse arc welding device of the present invention is characterized in that, when welding in the magnetic arc blow prevention mode, if the occurrence of magnetic arc blow is determined based on an increase in welding voltage, the increased value is increased.

[0012] A pulse arc welding method provided according to a second aspect of the present invention is a pulse arc welding method in which a welding wire is fed using a plurality of pulse arc welding power sources to generate an arc for welding, wherein the pulse arc welding power sources have a normal welding mode and a magnetic arc blow prevention mode, and when the plurality of pulse arc welding power sources each generate an arc to weld a common workpiece, the pulse arc welding power sources are switched to the magnetic arc blow prevention mode to perform welding. [Effects of the Invention]

[0013] According to the above configuration, for example, in a pulse arc welding apparatus and a pulse arc welding method, when a plurality of pulse arc welding power sources are used to generate arcs on a common workpiece for welding, deterioration of welding quality due to magnetic arc blow can be suppressed. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a configuration diagram of a pulse arc welding device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a detailed block diagram of the first pulse arc welding power supply PS1 and the second pulse arc welding power supply PS2 described above in FIG. 1. [Figure 3]3 is a timing chart of each signal in the pulse arc welding power supply of FIG. 2, illustrating the pulse arc welding method according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0016] Fig. 1 is a configuration diagram of a pulse arc welding apparatus according to an embodiment of the present invention. The diagram shows a case in which two pulse arc welding power sources are used to simultaneously weld two welding locations on a single common workpiece. Each component will be described below with reference to the diagram.

[0017] First pulse arc welding power supply PS1 outputs a first welding voltage Vw1 and a first welding current Iw1, and also outputs a first feed control signal Fc1 to first feeder FD1 for feeding first welding wire 11. First feeder FD1 receives this first feed control signal Fc1 and feeds first welding wire 11 through first welding torch 41. A first arc 31 is generated between first welding wire 11 and workpiece 2, and welding is performed. First feeder FD1 and first welding torch 41 are held by a robot (not shown).

[0018] A cable connects the positive terminal of first pulse arc welding power supply PS1 to first welding torch 41. A cable connects the negative terminal of first pulse arc welding power supply PS1 to workpiece 2.

[0019] The second pulse arc welding power supply PS2 outputs a second welding voltage Vw2 and a second welding current Iw2, and also outputs a second feed control signal Fc2 to the second feeder FD2 for feeding the second welding wire 12. The second feeder FD2 receives the second feed control signal Fc2 and feeds the second welding wire 12 through the second welding torch 42. A second arc 32 is generated between the second welding wire 12 and the workpiece 2, and welding is performed. The second feeder FD2 and the second welding torch 42 are held by a robot (not shown).

[0020] A cable connects the positive terminal of second pulse arc welding power supply PS2 to second welding torch 42. A cable connects the negative terminal of second pulse arc welding power supply PS2 to workpiece 2.

[0021] First welding current Iw1 and second welding current Iw2 are applied to a common workpiece 2, each forming a magnetic field. First arc 31 and second arc 32 are subjected to a force from this magnetic field, deflecting them and causing magnetic arc blow. While the figure shows a case where two pulse arc welding power sources are used, there are also cases where three or four power sources are used.

[0022] Figure 2 is a detailed block diagram of the first pulse arc welding power supply PS1 and the second pulse arc welding power supply PS2 described above in Figure 1. In the figure, the first and second descriptions of each block are omitted. Each block will be described below with reference to the figure.

[0023] The pulse arc welding power supply PS is composed of the following blocks: The main power supply circuit MC receives an AC commercial power supply (not shown) such as a three-phase 200V, performs output control such as inverter control in accordance with a drive signal Dv described below, and outputs a welding voltage Vw and welding current Iw suitable for welding. Although not shown, the main power supply circuit MC also includes a primary rectifier circuit that rectifies the AC commercial power supply, a capacitor that smooths the rectified DC, an inverter circuit that converts the smoothed DC into high-frequency AC in accordance with the drive signal Dv, an inverter transformer that steps down the high-frequency AC to a voltage suitable for welding, and a secondary rectifier circuit that rectifies the stepped-down high-frequency AC.

[0024] The reactor WL is inserted between the positive output of the main power supply circuit MC and the welding torch 4, and smoothes the output of the main power supply circuit MC.

[0025] The feeder FD is rotationally driven by a feed control signal Fc, which will be described later. The welding wire 1 is fed at a feed speed Fw through the welding torch 4 by the rotation of a feed roll 5 in the feeder FD, and an arc 3 is generated between the workpiece 2 and the feeder FD. The feeder FD and the welding torch 4 are mounted on a robot. A welding voltage Vw is applied between a power feed tip (not shown) in the welding torch 4 and the workpiece 2, and a welding current Iw flows between the workpiece 2 and the feeder FD.

[0026] The welding voltage detection circuit VD detects the welding voltage Vw and outputs a welding voltage detection signal Vd. The welding voltage averaging circuit VAV averages the welding voltage detection signal Vd (by passing it through a low-pass filter) and outputs a welding voltage average value signal Vav. The welding voltage setting circuit VR outputs a predetermined welding voltage setting signal Vr. The voltage error amplification circuit EV amplifies the error between the welding voltage setting signal Vr(+) and the welding voltage average value signal Vav(-) and outputs a voltage error amplification signal Ev.

[0027] The peak current modulation circuit IPC receives the voltage error amplified signal Ev, performs current modulation control based on the voltage error amplified signal Ev, and outputs a peak current setting signal Ipr. This circuit feedback controls the peak current setting signal Ipr so that the value of the welding voltage average value signal Vav is equal to the value of the welding voltage setting signal Vr. This allows arc length control.

[0028] The welding mode setting circuit MR outputs a welding mode setting signal Mr that is low in normal welding mode and high in magnetic arc blow prevention mode. The normal welding mode is when the workpiece 2 is welded with one pulse arc welding power source PS. The magnetic arc blow prevention mode is when the workpiece 2 is welded with multiple pulse arc welding power sources PS.

[0029] The number setting circuit NR outputs a number setting signal Nr for setting the number of pulse arc welding power sources PS that will simultaneously weld a common workpiece 2. The number setting signal Nr is an integer in the range of 2-4.

[0030] The base current setting circuit IBR receives the welding mode setting signal Mr, the number setting signal Nr, and a magnetic blow determination signal Ad (described later) as inputs, performs the following processing, and outputs a base current setting signal Ibr. 1) When the welding mode setting signal Mr is at a low level (normal welding mode), a base current setting signal Ibr having a predetermined initial value is output. For example, the initial value is set to 50 A. 2) When the welding mode setting signal Mr is at a high level (magnetic blow prevention mode) and the magnetic blow detection signal Ad is at a low level, an increment value of 25 × Nr is added to the initial value described above and the base current setting signal Ibr is output. Since Nr is an integer in the range of 2 to 4, when Nr = 2, Ibr = 100 A, when Nr = 3, Ibr = 125 A, and when Nr = 4, Ibr = 150 A. 3) When the welding mode setting signal Mr is at a high level (magnetic blow prevention mode) and the magnetic blow detection signal Ad is at a high level, an additional 50 A is added to the above-mentioned increased value to output the base current setting signal Ibr. Therefore, when Nr=2, Ibr=150 A, when Nr=3, Ibr=175 A, and when Nr=4, Ibr=200 A.

[0031] The peak rise period setting circuit TUR outputs a predetermined peak rise period setting signal Tur.

[0032] The peak period setting circuit TPR outputs a predetermined peak period setting signal Tpr.

[0033] The peak fall period setting circuit TKR receives the welding mode setting signal Mr, the number setting signal Nr, and a magnetic blow determination signal Ad (described later) as inputs, performs the following processing, and outputs a peak fall period setting signal Tkr. 1) When the welding mode setting signal Mr is at a low level (normal welding mode), a peak fall period setting signal Tkr having a predetermined initial value is output, for example, 1 ms. 2) When the welding mode setting signal Mr is at a high level (magnetic blow prevention mode) and the magnetic blow determination signal Ad is at a low level, an increment value of 0.25 × Nr is added to the initial value described above, and the peak fall period setting signal Tkr is output. Since Nr is an integer in the range of 2 to 4, when Nr = 2, Tkr = 1.5 ms, when Nr = 3, Tkr = 1.75 ms, and when Nr = 4, Tkr = 2 ms. 3) When the welding mode setting signal Mr is at a high level (magnetic blow prevention mode) and the magnetic blow detection signal Ad is at a high level, 0.25 is added to the above-mentioned increased value to output the peak fall period setting signal Tkr. Therefore, when Nr=2, Tkr=1.75 ms, when Nr=3, Tkr=2 ms, and when Nr=4, Tkr=2.25 ms.

[0034] The base period setting circuit TBR outputs a predetermined base period setting signal Tbr.

[0035] The welding current setting circuit IR receives the peak rise period setting signal Tur, the peak period setting signal Tpr, the peak fall period setting signal Tkr, the base period setting signal Tbr, the peak current setting signal Ipr, and the base current setting signal Ibr as inputs, performs the following processing, and outputs the welding current setting signal Ir. 1) During the period determined by the peak rise period setting signal Tur, the welding current setting signal Ir is output, which increases from the value of the base current setting signal Ibr to the value of the peak current setting signal Ipr. 2) Subsequently, during the period determined by the peak period setting signal Tpr, the peak current setting signal Ipr is output as the welding current setting signal Ir. 3) Subsequently, during the period determined by the peak fall period setting signal Tkr, the welding current setting signal Ir is output, which decreases from the value of the peak current setting signal Ipr to the value of the base current setting signal Ibr. 4) Subsequently, during the period determined by the base period setting signal Tbr, the base current setting signal Ibr is output as the welding current setting signal Ir. 5) Repeat steps 1) to 4) above.

[0036] The magnetic blow detection circuit AD receives the welding voltage detection signal Vd as an input, and when the value of the welding voltage detection signal Vd during the base period reaches or exceeds a predetermined reference voltage value Vt, it determines that magnetic blow has occurred and outputs a magnetic blow detection signal Ad that goes high. The occurrence of magnetic blow may also be determined when the rate of increase of the welding voltage detection signal Vd reaches or exceeds a reference value. Once the magnetic blow detection signal Ad goes high, it will maintain that state unless the welding conditions, such as the welding voltage setting signal Vr and the feed speed setting signal Fr, change.

[0037] The welding current detection circuit ID detects the welding current Iw and outputs a welding current detection signal Id. The current error amplifier circuit EI amplifies the error between the welding current setting signal Ir(+) and the welding current detection signal Id(-) and outputs a current error amplification signal Ei. The drive circuit DV receives the current error amplification signal Ei and an activation signal On from the robot control device RC (described later), and performs pulse width modulation control based on the current error amplification signal Ei when the activation signal On is high (welding starts) and outputs a drive signal Dv for driving the inverter circuit in the main power supply circuit MC, but does not output the drive signal Dv when the activation signal On is low (welding stops).

[0038] The feed speed setting circuit FR outputs a predetermined feed speed setting signal Fr.

[0039] The feed control circuit FC receives as input the feed speed setting signal Fr and a start signal On from the robot control device RC described later, and outputs a feed control signal Fc to the feeder FD for feeding the welding wire 1 at the value of the feed speed setting signal Fr when the start signal On is at a high level (welding starts), and outputs a feed control signal Fc to the feeder FD for stopping feeding when the start signal On is at a low level.

[0040] The robot control device RC moves a robot (not shown) in accordance with a pre-taught work program, and outputs a start signal On to command the start or stop of welding.

[0041] Fig. 3 is a timing chart of each signal in the pulse arc welding power supply of Fig. 2, which illustrates a pulse arc welding method according to an embodiment of the present invention. Fig. 3(A) shows the change over time in welding current Iw, Fig. 3(B) shows the change over time in welding voltage Vw, and Fig. 3(C) shows the change over time in magnetic arc blow detection signal Ad. The operation of each signal will be explained below with reference to the diagram.

[0042] In the pulse period Tf from time t1 to t2, during the peak rise period Tu, as shown in FIG. 1A, an upward transition current Iu is passed, which rises from a base current Ib to a peak current Ip, and as shown in FIG. 1B, an upward transition voltage is applied between the welding wire and the workpiece, which rises from a base voltage Vb to a peak voltage Vp. During the subsequent peak period Tp, as shown in FIG. 1A, a peak current Ip having a large current value equal to or greater than the critical value is passed to transfer a droplet from the welding wire, and as shown in FIG. 1B, a peak voltage Vp proportional to the arc length is applied. During the subsequent peak fall period Tk, as shown in FIG. 1A, a downward transition current Ik is passed, which falls from the peak current Ip to a base current Ib, and as shown in FIG. 1B, a downward transition voltage is applied, which falls from the peak voltage Vp to a base voltage Vb. During the subsequent base period Tb, as shown in Figure 1(A), a base current Ib of a small value below the critical value is applied to prevent droplet formation, and as shown in Figure 1(B), a base voltage Vb proportional to the arc length is applied. The arc length increases during the peak period Tp and decreases during the base period Tb.

[0043] The peak current Ip is feedback-controlled (current modulation-controlled) so that the value of the welding voltage average value signal Vav of FIG. 2 is equal to the predetermined value of the welding voltage setting signal Vr of FIG. 2. To achieve this, the peak rise period Tu determined by the peak rise period setting signal Tur of FIG. 2, the peak period Tp determined by the peak period setting signal Tpr of FIG. 2, the peak fall period Tk determined by the peak fall period setting signal Tkr of FIG. 2, the base period Tb determined by the base period setting signal Tbr of FIG. 2, and the base current Ib determined by the base current setting signal Ibr of FIG. 2 are all set to predetermined values. The peak current Ip is controlled by the peak current setting signal Ipr of FIG. 2, and is determined by feedback control so that the average value of the welding voltage Vw is equal to the predetermined welding voltage setting value. For example, Tu = 1 ms, Tp = 1.2 ms, and Tb = 3 ms. Ip is not a predetermined value, but varies within a range of approximately 400 to 550 A.

[0044] At time t11 during the base period Tb, a magnetic arc blow occurs, deflecting the arc and lengthening the arc length. As a result, the base voltage Vb rises from its normal value to a large value, as shown in (B) of the figure. Then, at time t12, the base voltage Vb exceeds a predetermined reference voltage Vt (approximately 50 V), indicated by the dashed line. When it is determined that the base voltage Vb has exceeded the reference voltage Vt, the magnetic arc blow detection signal Ad changes to a high level, as shown in (C) of the figure. In response to this, the base current Ib increases, as shown in (A) of the figure. This further increases the arc rigidity, thereby suppressing arc deflection due to magnetic arc blow. As a result, at time t13, the base voltage Vb returns to approximately its normal value, as shown in (B) of the figure. As shown in (C) of the figure, the magnetic arc blow detection signal Ad remains high even after time t12 unless the welding conditions change.

[0045] The pulse period from time t2 to t3 repeats the operation of the previous period. However, as shown in (C) of the same figure, because the magnetic blow detection signal Ad is at a high level, the length of the peak fall period Tk is longer than in the previous period, and the value of the base current Ib is the same as that after time t12 in the previous period. As a result, the occurrence of magnetic blow is suppressed, and as shown in (B) of the same figure, the base voltage Vb remains at approximately the normal value.

[0046] The value of the base current Ib and the length of the peak fall period Tk are set as follows depending on the number of pulse arc welding power sources PS. (1) When welding a workpiece with one pulse arc welding power source PS The base current Ib is set to the initial value (50 A), and the peak fall time Tk is set to the initial value (1 ms). (2) When welding a common workpiece using multiple pulse arc welding power sources PS When there are two units, Ib = 100A and Tk = 1.5ms; when there are three units, Ib = 125A and Tk = 1.75ms; and when there are four units, Ib = 150A and Tk = 2ms. (3) When multiple pulse arc welding power sources PS are used to weld a common workpiece and the magnetic arc blow detection signal Ad is at a high level The value of the base current Ib is the value obtained by adding 50 A to the value in (2) above, and the length of the peak fall period Tk is the value obtained by adding 2.5 ms to the value in (2) above.

[0047] In the above-described embodiment, the case where the value of the base current Ib and the length of the peak fall period Tk are increased in the magnetic blow countermeasure mode has been described, but it is also possible to increase only one of them.

[0048] The effects of this embodiment are described below. According to this embodiment, the pulse arc welding power supply has a normal welding mode and a magnetic arc blow prevention mode. When multiple pulse arc welding power supplies each generate an arc to weld a common workpiece, the pulse arc welding power supply switches to the magnetic arc blow prevention mode to perform welding. When multiple pulse arc welding power supplies are used to weld a common workpiece, the arc is likely to be deflected due to the influence of the magnetic fields generated by the welding currents, resulting in magnetic arc blow. In conventional technology, control to suppress magnetic arc blow individually is initiated after the occurrence of magnetic arc blow is determined. In contrast, in this embodiment, when multiple pulse arc welding power supplies are used to weld a common workpiece, the welding is performed by switching to the magnetic arc blow prevention mode to suppress magnetic arc blow in advance. This makes it possible to prevent deterioration of welding quality due to magnetic arc blow in advance.

[0049] More preferably, according to this embodiment, in the magnetic arc blow prevention mode, the value of the base current and / or the length of the peak fall period are increased by an increment compared to the normal welding mode. Magnetic arc blow occurs during the base period when a small current value is flowing. Therefore, by increasing the value of the base current, the rigidity of the arc is strengthened, thereby suppressing the occurrence of magnetic arc blow. Furthermore, by increasing the length of the peak fall period, the arc length at the start of the base period is shortened. When the arc length is shortened, it is possible to suppress arc deflection due to a magnetic field. As a result, in this embodiment, the occurrence of magnetic arc blow can be suppressed and welding quality can be improved.

[0050] More preferably, according to this embodiment, the increase value is set according to the number of pulse arc welding power sources. As the number of pulse arc welding power sources increases, the generated magnetic field also increases, making magnetic arc blow more likely to occur. Therefore, by setting the value of the base current and / or the length of the peak fall period according to the number of power sources, the occurrence of magnetic arc blow can be effectively suppressed.

[0051] More preferably, according to this embodiment, when welding is performed in the magnetic blow prevention mode and it is determined that magnetic blow has occurred based on an increase in the welding voltage, the increase value is increased. Even when welding is performed in the magnetic blow prevention mode, magnetic blow may occur depending on the shape of the workpiece. In such cases, when it is determined that magnetic blow has occurred, the increase value is further increased to more reliably suppress the occurrence of magnetic blow.

[0052] Furthermore, according to this embodiment, the pulse arc welding power source has a normal welding mode and a magnetic arc blow prevention mode, and when multiple pulse arc welding power sources each generate an arc to weld a common workpiece, the pulse arc welding power sources are switched to the magnetic arc blow prevention mode to perform welding. The pulse arc welding method according to this embodiment can achieve the above-mentioned effects. [Explanation of symbols]

[0053] 1: welding wire, 11: first welding wire, 12: second welding wire, 2: work, 3: arc, 31: first arc, 32: second arc, 4: welding torch, 41: first welding torch, 42: second welding torch, 5: feed roll, AD: magnetic blow detection circuit, Ad: magnetic blow detection signal, DV: drive circuit, Dv: drive signal, EI: current error amplifier circuit, Ei: current error amplifier signal, EV: voltage error amplifier circuit, Ev: voltage error amplifier signal, FC: feed control circuit, Fc: feed control signal, Fc1: first Feed control signal, Fc2: second feed control signal, FD: feeder, FD1: first feeder, FD2: second feeder, FR: feed speed setting circuit, Fr: feed speed setting signal, Fw: feed speed, Ib: base current, IBR: base current setting circuit, Ibr: base current setting signal, ID: welding current detection circuit, Id: welding current detection signal, Ik: falling transition current, Ip: peak current, IPC: peak current modulation circuit, Ipr: peak current setting signal, IR: welding current setting circuit, Ir: welding current setting signal, I u: rising transition current, Iw: welding current, MC: main power supply circuit, MR: welding mode setting circuit, Mr: welding mode setting signal, NR: number of units setting circuit, Nr: number of units setting signal, On: start signal, PS: pulse arc welding power source, PS1: first pulse arc welding power source, PS2: second pulse arc welding power source, RC: robot control device, Tb: base period, TBR: base period setting circuit, Tbr: base period setting signal, Tk: peak fall period, TKR: peak fall period setting circuit, Tkr: peak Peak fall period setting signal, Tp: Peak period, TPR: Peak period setting circuit, Tpr: Peak period setting signal, Tu: Peak rise period, TUR: Peak rise period setting circuit, Tur: Peak rise period setting signal, VAV: Welding voltage averaging circuit, Vav: Welding voltage average value signal, Vb: Base voltage, VD: Welding voltage detection circuit, Vd: Welding voltage detection signal, Vp: Peak voltage, VR: Welding voltage setting circuit, Vr: Welding voltage setting signal, Vt: Reference voltage value, Vw: Welding voltage, WL: Reactor

Claims

1. A pulse arc welding apparatus having a plurality of pulse arc welding power sources that feed a welding wire to generate an arc for welding, The pulse arc welding power source has a normal welding mode and a magnetic arc blow prevention mode, a pulse arc welding power supply for switching to the magnetic arc blow prevention mode when the plurality of pulse arc welding power supplies each generate an arc to weld a common workpiece;

2. 2. The pulse arc welding device according to claim 1, wherein the value of the base current and / or the length of the peak fall period are increased by an increment value in the magnetic arc blow prevention mode compared to the normal welding mode.

3. The pulse arc welding device according to claim 2 , wherein the increase value is set in accordance with the number of the plurality of pulse arc welding power sources.

4. 4. The pulse arc welding device according to claim 2, wherein when welding is performed in the magnetic arc blow prevention mode, if occurrence of magnetic arc blow is detected based on an increase in welding voltage, the increased value is increased.

5. A pulse arc welding method in which welding wires are fed by a plurality of pulse arc welding power sources to generate arcs for welding, comprising: The pulse arc welding power source has a normal welding mode and a magnetic arc blow prevention mode, a pulse arc welding method, characterized in that when the plurality of pulse arc welding power sources each generate an arc to weld a common workpiece, the pulse arc welding power sources are switched to the magnetic arc blow prevention mode to perform welding.

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