Pulse Arc Welding Method

Abstract

To perform high-quality welding on a thin plate of which the base material is aluminum and which includes a large gap in a welding joint part.SOLUTION: In a pulse arc welding method for welding an aluminum material by performing feeding Fw of a welding wire, the welding is performed while alternately switching a period (times t2-t3) in which AC pulse arc welding is performed while repeating an electrode positive polarity period and an electrode negative polarity period and a period (times t3-t4) in which DC pulse arc welding is performed while repeating a peak period in which a peak current is electrified with an electrode negative polarity, and a base period in which a base current is electrified. A time ratio of the period, in which the AC pulse arc welding is performed, occupied in a total welding period ranges from 30% or more to 70% or less.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a pulse arc welding method for feeding a welding wire and welding aluminum materials. [Background technology]

[0002] In order to reduce the heat input to the base material and weld thin plates with high quality, inventions such as those disclosed in Patent Documents 1 and 2 are commonly used. In the AC pulse arc welding method disclosed in Patent Document 1, welding is performed by feeding a welding wire and repeating one cycle of passing a peak current and a base current during an electrode positive polarity period and passing an electrode negative polarity current during an electrode negative polarity period. In this AC pulse arc welding, by adjusting the electrode negative polarity period, the electrode negative polarity ratio, which is the time ratio of the electrode negative polarity period in one cycle, can be changed to control the heat input to the base metal. This enables low heat input welding and high-quality thin plate welding.

[0003] In the welding method disclosed in Patent Document 2, welding is performed by feeding a welding wire and alternating between a period of pulse arc welding and a period of DC pulse arc welding. In this welding method, the heat input to the base material can be controlled by adjusting the ratio between the period of pulse arc welding and the period of DC pulse arc welding. This enables low heat input welding and high-quality thin plate welding. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. WO2018 / 079345 [Patent Document 2] Patent Publication No. 2021-53649 Summary of the Invention [Problem to be solved by the invention]

[0005] In thin plate welding, when there is a gap in the weld joint, it is necessary to form a bead shape with a small dilution ratio, with a small penetration area and a large reinforcement area. However, with the conventional welding methods disclosed in Patent Documents 1 and 2, it was difficult to achieve high-quality welding of thin plates with large gaps when the base metal was aluminum.

[0006] Therefore, an object of the present invention is to provide a pulse arc welding method that can perform high-quality welding on thin plates whose base material is aluminum and which have a large gap at the weld joint. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems, the invention of claim 1 is as follows: A pulse arc welding method for feeding a welding wire and welding an aluminum material, comprising: welding is performed by alternately switching between a period of AC pulse arc welding in which an electrode positive polarity period and an electrode negative polarity period are repeated, and a period of DC pulse arc welding in which a peak period in which a peak current is passed with an electrode negative polarity and a base period in which a base current is passed are repeated; The pulse arc welding method is characterized by the above.

[0008] The invention of claim 2 is as follows: The time ratio of the period during which the AC pulse arc welding is performed to the total welding period is in the range of 30% to 70%. 2. The pulse arc welding method according to claim 1, wherein: [Effects of the Invention]

[0011] According to the present invention, high-quality welding can be performed on thin plates whose base material is aluminum and which have a large gap at the weld joint. [Brief explanation of the drawings]

[0012] [Figure 1]1 is a block diagram of a welding power source for carrying out a pulse arc welding method according to an embodiment of the present invention. [Figure 2] 2 is a timing chart of each signal in FIG. 1 illustrating the pulse arc welding method according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0014] 1 is a block diagram of a welding power source for carrying out a pulse arc welding method according to an embodiment of the present invention. In this diagram, the high voltage application circuit used during polarity switching is omitted. Each block will be described below with reference to this diagram.

[0015] The inverter circuit INV receives an AC commercial power supply (not shown) such as a three-phase 200V, rectifies and smooths the DC voltage, and performs inverter control by pulse width modulation control using a current error amplification signal Ei (described later), to output a high-frequency AC voltage. The inverter transformer INT reduces the high-frequency AC voltage to a voltage value suitable for arc welding. The secondary rectifiers D2a to D2d rectify the reduced high-frequency AC voltage to DC.

[0016] The electrode positive polarity transistor PTR is turned on by an electrode positive polarity drive signal Pd (described later), and at this time the output of the welding power supply has electrode positive polarity EP. The electrode negative polarity transistor NTR is turned on by an electrode negative polarity drive signal Nd (described later), and at this time the output of the welding power supply has electrode negative polarity EN.

[0017] The reactor WL smoothes the ripple in the output.

[0018] The welding wire 1 is fed through the welding torch 4 by the rotation of a feed roll 5 connected to a wire feed motor WM, and an arc 3 is generated between the welding wire 1 and the base metal 2. A welding voltage Vw is applied between the welding wire 1 and the base metal 2, and a welding current Iw flows between the welding wire 1 and the base metal 2. The base metal 2 is made of aluminum. The shielding gas ejected from the tip of the welding torch 4 is 100% argon gas.

[0019] The voltage detection circuit VD detects the welding voltage Vw and outputs a voltage detection signal Vd. The voltage averaging circuit VAV averages the absolute value of the voltage detection signal Vd and outputs a voltage average value signal Vav. The voltage setting circuit VR outputs a predetermined voltage setting signal Vr. The voltage error amplifier circuit EV amplifies the error between the voltage setting signal Vr and the voltage average value signal Vav and outputs a voltage error amplification signal Ev.

[0020] The electrode positive polarity peak period setting circuit TPR outputs a predetermined electrode positive polarity peak period setting signal Tpr, and the electrode positive polarity base period setting circuit TBR outputs a predetermined electrode positive polarity base period setting signal Tbr.

[0021] The electrode negative polarity period setting circuit TNR outputs a predetermined electrode negative polarity period setting signal Tnr.

[0022] The timer circuit TM receives as input a welding method switching signal Sm (to be described later), the electrode negative polarity period setting signal Tnr, the electrode positive polarity peak period setting signal Tpr, and the electrode positive polarity base period setting signal Tbr, performs the following processing, and outputs a timer signal Tm. 1) When the welding method switching signal Sm changes to 1, or when the electrode positive polarity base period Tb ends, the electrode negative polarity period Tn set by the electrode negative polarity period setting signal Tnr begins, and the timer signal Tm=1 is output. 2) Then, the electrode positive polarity peak period Tp set by the electrode positive polarity peak period setting signal Tpr begins, and the timer signal Tm=2 is output. 3) Then, the electrode positive polarity base period Tb set by the electrode positive polarity base period setting signal Tbr begins, and the timer signal Tm=3 is output. 4) During the period when the welding method switching signal Sm=1, the above steps 1) to 3) are repeated.

[0023] The electrode positive peak current setting circuit IPR receives the voltage error amplified signal Ev, performs feedback control so that the value of the voltage average signal Vav becomes equal to the value of the voltage setting signal Vr, and outputs the electrode positive peak current setting signal Ipr. This circuit feedback controls the electrode positive peak current Ip so that the arc length becomes an appropriate value.

[0024] The electrode positive polarity base current setting circuit IBR outputs a predetermined electrode positive polarity base current setting signal Ibr.

[0025] The electrode negative polarity current setting circuit INR outputs a predetermined electrode negative polarity current setting signal Inr.

[0026] The switching circuit SW receives the timer signal Tm, the electrode positive polarity peak current setting signal Ipr, the electrode positive polarity base current setting signal Ibr, and the electrode negative polarity current setting signal Inr as inputs, performs the following processing, and outputs the current setting signal Ir. 1) When the timer signal Tm=1, the electrode negative polarity current setting signal Inr is output as the current setting signal Ir. 2) When the timer signal Tm=2, the electrode positive polarity peak current setting signal Ipr is output as the current setting signal Ir. 3) When the timer signal Tm=3, the electrode positive polarity base current setting signal Ibr is output as the current setting signal Ir.

[0027] The DC pulse arc welding current setting circuit ISR receives a welding method switching signal Sm (described later) as input, and outputs a DC pulse arc welding current setting signal Isr by alternately repeating a predetermined base current setting value during a predetermined base period and a predetermined peak current setting value during a predetermined peak period from the time when the welding method switching signal Sm changes to 2 (DC pulse arc welding period Ts).

[0028] The AC pulse arc welding period setting circuit TAR outputs a predetermined AC pulse arc welding period setting signal Tar.

[0029] The DC pulse arc welding period setting circuit TSR outputs a predetermined DC pulse arc welding period setting signal Tsr.

[0030] The welding method switching circuit SM receives the AC pulse arc welding period setting signal Tar, the DC pulse arc welding period setting signal Tsr, the timer signal Tm, and the DC pulse arc welding current setting signal Isr as inputs, performs the following processing, and outputs a welding method switching signal Sm. 1) When the period set by the AC pulse arc welding period setting signal Tar has elapsed since the welding method switching signal Sm=1 and the timer signal Tm=1 (electrode negative polarity period Tn) is in effect, the welding method switching signal Sm=2 is output. 2) When the period set by the electrode negative polarity DC pulse arc welding period setting signal Tsr has elapsed since the welding method switching signal Sm changed to 2, and the value of the DC pulse arc welding current setting signal Isr is the predetermined base current setting value, the welding method switching signal Sm=1 is output. 3) Repeat steps 1) and 2) above.

[0031] The current detection circuit ID detects the absolute value of the welding current Iw and outputs a current detection signal Id.

[0032] The current control setting circuit ICR receives the above current setting signal Ir, the DC pulse arc welding current setting signal Isr, and the welding method switching signal Sm as inputs, and outputs a current control setting signal Icr which becomes the current setting signal Ir when the welding method switching signal Sm=1 (AC pulse arc welding period Ta), and which becomes the DC pulse arc welding current setting signal Isr when the welding method switching signal Sm=2 (DC pulse arc welding period Ts).

[0033] The current error amplifier circuit EI amplifies the error between the current control setting signal Icr and the current detection signal Id, and outputs a current error amplified signal Ei.

[0034] The drive circuit DV receives the welding method switching signal Sm and the timer signal Tm, performs the following processing, and outputs a drive signal Dv. The drive signal Dv is formed from an electrode negative polarity drive signal Nd and an electrode positive polarity drive signal Pd. 1) When the welding method switching signal Sm=2 or the timer signal Tm=1, the electrode negative polarity drive signal Nd is output. 2) When the welding method switching signal Sm=1 and the timer signal Tm=2 or 3, the electrode positive polarity drive signal Pd is output. Therefore, the electrode polarity is negative EN during the DC pulse arc welding period Ts, negative EN during the electrode negative polarity period Tn during the AC pulse arc welding period Ta, and positive EP during the electrode positive polarity peak period Tp and the electrode positive polarity base period Tb.

[0035] The AC pulse arc welding feed rate setting circuit FAR outputs a predetermined AC pulse arc welding feed rate setting signal Far.

[0036] The DC pulse arc welding feed rate setting circuit FSR outputs a predetermined DC pulse arc welding feed rate setting signal Fsr.

[0037] The feed rate setting circuit FR receives the welding method switching signal Sm, the AC pulse arc welding feed rate setting signal Far, and the DC pulse arc welding feed rate setting signal Fsr as inputs, and outputs the AC pulse arc welding feed rate setting signal Far as the feed rate setting signal Fr when the welding method switching signal Sm=1, and outputs the DC pulse arc welding feed rate setting signal Fsr as the feed rate setting signal Fr when the welding method switching signal Sm=2.

[0038] The feed control circuit FC receives the feed speed setting signal Fr as an input and outputs a feed control signal Fc to the wire feed motor WM for feeding the welding wire 1 at a feed speed Fw corresponding to this value.

[0039] Fig. 2 is a timing chart of each signal in the welding power source of Fig. 1, which illustrates a pulse arc welding method according to an embodiment of the present invention. Fig. 2(A) shows the change over time of the welding method switching signal Sm, Fig. 2(B) shows the change over time of the timer signal Tm, Fig. 2(C) shows the change over time of the feed rate Fw, Fig. 2(D) shows the change over time of the welding current Iw, Fig. 2(E) shows the change over time of the welding voltage Vw, and Fig. 2(F) shows the change over time of the drive signal Dv. The operation of each signal will be explained below with reference to Fig. 2.

[0040] The welding method switching signal Sm shown in Figure 1A corresponds to an AC pulse arc welding period Ta when Sm = 1, and to an electrode negative DC pulse arc welding period Ts when Sm = 2. The timer signal Tm shown in Figure 1B corresponds to an electrode negative polarity period Tn when Tm = 1, an electrode positive polarity peak period Tp when Tm = 2, and an electrode positive polarity base period Tb when Tm = 3. The welding current Iw shown in Figure 1D corresponds to an electrode positive polarity EP, where current flows from the welding wire to the base metal, and a negative value corresponds to an electrode negative polarity EN, where current flows from the base metal to the welding wire. The welding voltage Vw shown in Figure 1E corresponds to an electrode positive polarity EP, where the welding wire is positive and the base metal is negative, and a negative value corresponds to an electrode negative polarity EN, where the base metal is positive and the welding wire is negative. When the magnitudes of the welding current Iw and welding voltage Vw are indicated, the absolute values ​​are used regardless of the electrode polarity. The drive signal Dv shown in (F) of the same figure indicates that when it is at a high level, the electrode negative polarity drive signal Nd in Figure 1 is output, resulting in electrode negative polarity EN, and when it is at a low level, the electrode positive polarity drive signal Pd in ​​Figure 1 is output, resulting in electrode positive polarity EP. To prevent arc interruption when switching polarity, a restrike voltage of several hundred volts is applied for a short time between the welding wire and the base metal, but this is not shown in the figure.

[0041] As shown in the same figure (A), the welding method switching signal Sm is Sm=2 (DC pulse arc welding period Ts) before time t2, 1 (AC pulse arc welding period Ta) from time t2 to t3, 2 (DC pulse arc welding period Ts) from time t3 to t4, and 1 (AC pulse arc welding period Ta) from time t4 onwards.

[0042] (1) Operation of the negative electrode polarity DC pulse arc welding period Ts before time t2 During this period, as shown in FIG. 1A, the welding method switching signal Sm becomes 2, and the DC pulse arc welding period Ts is set to electrode negative polarity. As shown in FIG. 1F, the drive signal Dv becomes high level, resulting in electrode negative polarity EN. Therefore, the welding current Iw shown in FIG. 1D and the welding voltage Vw shown in FIG. 1E are negative values. The period from time t1 to t11 is a predetermined peak period, and the period from time t11 to t2 is a predetermined base period. As shown in FIG. 1D, the welding current Iw is set by the DC pulse arc welding current setting signal Isr of FIG. 1, and is a predetermined peak current value during the peak period and a predetermined base current value during the base period. As shown in FIG. 1E, the welding voltage Vw is a value proportional to the arc length, is a peak voltage value during the peak period, and a base voltage value during the base period. As shown in FIG. 1C, the feed rate Fw is a value set by the DC pulse arc welding feed rate setting signal Fsr of FIG. 1. Here, the case where arc length control is not performed during the DC pulse arc welding period Ts has been described, but as will be described later, arc length control similar to that during the AC pulse arc welding period Ta may be performed.

[0043] (2) Operation during AC pulse arc welding period Ta from time t2 to t3 At time t2, the period set by the DC pulse arc welding period setting signal Tsr in FIG. 1 has elapsed since the welding method switching signal Sm changed to 2, and the welding current Iw is at its base current value (base period). Therefore, the welding method switching signal Sm changes to 1, and the AC pulse arc welding period Ta begins. Therefore, if the peak period occurs when the period set by the DC pulse arc welding period setting signal Tsr in FIG. 1 has elapsed since the welding method switching signal Sm changed to 2, the AC pulse arc welding period Ta is delayed until the base period begins, and the AC pulse arc welding period Ta always begins with the electrode negative polarity period Tn. Therefore, as shown in FIG. 1B, the timer signal Tm is 1 (electrode negative polarity period Tn) from time t2 to t21, 2 (electrode positive polarity peak period Tp) from time t21 to t22, and 3 (electrode positive polarity base period Tb) from time t22 to t23. As shown in FIG. 1(C), the feed rate Fw changes to a value set by the AC pulse arc welding feed rate setting signal Far in FIG. (21) During the electrode negative polarity period Tn from time t2 to t21, as shown in (F) of the figure, the drive signal Dv becomes high level and the electrode polarity becomes negative EN. As shown in (D) of the figure, the welding current Iw becomes a predetermined electrode negative polarity current with a negative value, and as shown in (E) of the figure, the welding voltage Vw becomes an arc voltage value with a negative value proportional to the arc length. The electrode negative polarity period may be formed from an electrode negative polarity base period in which an electrode negative polarity base current flows and an electrode negative polarity peak period in which an electrode negative polarity peak current flows. (22) During the electrode positive polarity peak period Tp from time t21 to t22, as shown in (F) of the figure, the drive signal Dv becomes low level and the polarity is reversed to the electrode positive polarity EP. As shown in (D) of the figure, the welding current Iw becomes a feedback-controlled electrode positive polarity peak current of a positive value, and as shown in (E) of the figure, the welding voltage Vw becomes a positive arc voltage value proportional to the arc length. The value of the electrode positive polarity peak current is feedback-controlled so that the average value of the welding voltage Vw is equal to the value of the voltage setting signal Vr of Figure 1. This controls the arc length to an appropriate value. The electrode positive polarity peak period Tp is composed of a rise period, a maximum value period, and a fall period. In addition to the electrode positive polarity peak current modulation method described above, other methods of arc length control include periodic modulation and electrode positive polarity peak period modulation. (23) During the electrode positive polarity base period Tb from time t22 to t23, as shown in (F) of the figure, the drive signal Dv becomes low level and the electrode positive polarity EP is maintained. As shown in (D) of the figure, the welding current Iw becomes a predetermined electrode positive polarity base current of a positive value, and as shown in (E) of the figure, the welding voltage Vw becomes a positive arc voltage value proportional to the arc length. In the figure, two periods of the waveform are displayed during the period from time t2 to t3.

[0044] (3) Operation of the DC pulse arc welding period Ts with negative electrode polarity from time t3 to t4 At time t3, the period set by the AC pulse arc welding period setting signal Tar in FIG. 1 has elapsed since the welding method switching signal Sm changed to Sm=1 at time t1, and the timer signal Tm=1 (electrode negative polarity period Tn) is in effect. Therefore, the welding method switching signal Sm changes to Sm=2, and the electrode negative DC pulse arc welding period Ts begins. Therefore, if the period set by the AC pulse arc welding period setting signal Tar in FIG. 1 has elapsed since the welding method switching signal Sm=1 and is not in the electrode negative polarity period Tn, the welding method switching signal Sm is delayed until the electrode negative polarity period Tn is reached, and the welding method switching signal Sm transitions to the electrode negative DC pulse arc welding period Ts. This period always begins with the base period. During this period, the drive signal Dv becomes high, resulting in electrode negative polarity EN, as shown in FIG. 1(F). As shown in FIG. 1(C), the feed rate Fw changes to the value set by the DC pulse arc welding feed rate setting signal Fsr in FIG. 1. (31) During the base period from time t3 to t31, as shown in (D) of the same figure, the welding current Iw has a negative base current value, and as shown in (E) of the same figure, the welding voltage Vw has a negative base voltage value. (32) During the peak period from time t31 to t32, as shown in (D) of the same figure, the welding current Iw has a negative peak current value, and as shown in (E) of the same figure, the welding voltage Vw has a negative peak voltage value. (33) The period from time t32 to t33 becomes the base period again, and the above operation is repeated. From time t33 onwards, it becomes the peak period again. In the same figure, two cycles of the waveform are displayed during the period from time t3 to t4.

[0045] At time t4, the operation returns to that at time t2, and the above operation is repeated. Each of the AC pulse arc welding period Ta and the electrode negative polarity DC pulse arc welding period Ts has a cycle of about 10 ms. Each period includes at least one cycle and is in the range of about 1 to 50 cycles.

[0046] Numerical examples of the above parameters are shown below. Base material: aluminum, shielding gas: 100% argon gas (1) AC pulse arc welding parameters Feed speed = 10 m / min (150 A), welding voltage = 18 V, electrode negative polarity ratio = 20% Electrode negative polarity period = 1.5 ms, electrode negative polarity current = 150 A Electrode positive polarity peak period = 3.0 ms (rise period = 1.0 ms + maximum value period = 1.0 ms + fall period = 1.0 ms), electrode positive polarity peak current (feedback value) = approx. 350 A Electrode positive polarity base period = 4.0 ms, Electrode positive polarity base current = 50 A (2) DC pulsed arc welding parameters for negative electrode polarity Feed speed = 12 m / min (125 A), welding voltage = 14 V Peak period = 2ms, Base period = 2ms Peak current = 150A, base current = 100A

[0047] The effects of this embodiment will be described below. According to this embodiment, in a pulse arc welding method for welding aluminum materials using a welding wire, welding is performed by alternately switching between a period of AC pulse arc welding, which alternates between periods of electrode positive polarity and periods of electrode negative polarity, and a period of DC pulse arc welding, which alternates between a peak period in which a peak current is passed with electrode negative polarity and a base period in which a base current is passed with electrode negative polarity. To perform low-heat-input, high-deposition welding on thin plates with large gaps at the weld joint, DC pulse arc welding with electrode negative polarity is most effective. However, when the base metal is aluminum, DC pulse arc welding with electrode negative polarity does not provide a cleaning effect to remove the oxide film, resulting in poor welding. To solve this problem, a period of AC pulse arc welding is added. By adding AC pulse arc welding, a cleaning effect occurs during the electrode positive polarity peak period and the electrode positive polarity base period, thereby removing the oxide film and achieving good welding. Furthermore, AC pulse arc welding includes a period of electrode negative polarity, resulting in low-heat-input, high-deposition welding. As a result, in this embodiment, high-quality welding can be performed on thin plates whose base material is aluminum and which have large gaps at the weld joints.

[0048] More preferably, according to this embodiment, the time ratio of the period during which AC pulse arc welding is performed to the total welding period is in the range of 30% to 70%. If the time ratio is less than 30%, the cleaning effect is insufficient, resulting in poor welding. If the time ratio is more than 70%, the low heat input, high welding efficiency achieved by DC pulse arc welding with a negative electrode polarity is reduced, narrowing the range of application.

[0049] More preferably, according to this embodiment, when AC pulse arc welding is in the electrode negative polarity period, switching is made to the base period of DC pulse arc welding. The transition from the electrode negative polarity period of AC pulse arc welding to the base period of DC pulse arc welding with electrode negative polarity is smooth and the welding state is stabilized because both have the same polarity and the difference between the current values ​​is small.

[0050] More preferably, according to this embodiment, when the electrode-negative polarity DC pulse arc welding is in the base period, the welding is switched to the electrode-negative polarity period of AC pulse arc welding. The transition from the base period of electrode-negative polarity DC pulse arc welding to the electrode-negative polarity period of AC pulse arc welding is smooth and the welding state is stabilized because both have the same polarity and the difference between the current values ​​is small. [Explanation of symbols]

[0051] 1 welding wire 2 Base material 3. Arc 4 welding torches 5 Feeding roll D2a~D2d Secondary rectifier DV drive circuit Dv drive signal EI current error amplifier circuit Ei Current error amplification signal EN electrode negative polarity EP electrode positive polarity EV voltage error amplifier circuit Ev Voltage error amplified signal FAR AC pulse arc welding feed rate setting circuit Far AC pulse arc welding feed speed setting signal FC feed control circuit Fc feed control signal FR feed speed setting circuit Fr feed speed setting signal FSR DC pulse arc welding feed rate setting circuit Fsr DC pulse arc welding feed speed setting signal Fw Feed speed IBR electrode positive polarity base current setting circuit Ibr Electrode positive polarity base current setting signal ICR current control setting circuit Icr Current control setting signal ID current detection circuit Id Current detection signal INR Electrode negative polarity current setting circuit Inr Electrode negative polarity current setting signal INT Inverter transformer INV Inverter circuit Ip Electrode positive polarity peak current IPR electrode positive polarity peak current setting circuit Ipr Electrode positive polarity peak current setting signal Ir Current setting signal ISR DC pulse arc welding current setting circuit Isr DC pulse arc welding current setting signal Iw Welding current Nd electrode negative polarity drive signal NTR negative polarity transistor Pd electrode positive polarity drive signal PTR positive polarity transistor SM Welding method switching circuit Sm welding method switching signal SW switching circuit Ta AC pulsed arc welding period TAR AC pulse arc welding period setting circuit Tar AC pulse arc welding period setting signal Tb electrode positive polarity base period TBR electrode positive polarity base period setting circuit Tbr Electrode positive polarity base period setting signal TM timer circuit Tm timer signal Tn electrode negative polarity period TNR electrode negative polarity period setting circuit Tnr Electrode negative polarity period setting signal Tp electrode positive polarity peak period TPR electrode positive polarity peak period setting circuit Tpr electrode positive polarity peak period setting signal Ts DC pulse arc welding period TSR DC pulse arc welding period setting circuit Tsr DC pulse arc welding period setting signal VAV voltage averaging circuit Vav Average voltage signal VD voltage detection circuit Vd Voltage detection signal VR voltage setting circuit Vr voltage setting signal Vw welding voltage WL reactor WM Wire feed motor

Claims

1. A pulse arc welding method for feeding a welding wire and welding an aluminum material, comprising: welding is performed by alternately switching between a period of AC pulse arc welding in which an electrode positive polarity period and an electrode negative polarity period are repeated, and a period of DC pulse arc welding in which a peak period in which a peak current is passed with an electrode negative polarity and a base period in which a base current is passed are repeated; A pulse arc welding method characterized by:

2. The time ratio of the period during which the AC pulse arc welding is performed to the total welding period is in the range of 30% to 70%.

2. The pulse arc welding method according to claim 1.

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