JP4175781B2 - Multi-electrode pulse arc welding control method and welding apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a multi-electrode pulse arc welding method in which two arcs are generated between two welding wires electrically insulated from one welding torch and a workpiece to be welded. The present invention relates to a multi-electrode pulse arc welding control method that suppresses an arc generation state from becoming unstable due to mutual interference of arcs caused by forces acting between each other.
[0002]
[Prior art]
In the multi-electrode pulse arc welding method, two welding wires are fed through two electrically insulated contact tips provided on one welding torch, and two welding wires are connected between the welding wire and the work piece. Welding is performed by generating a pulse arc. In this welding method, since two welding wires are melted simultaneously, a high welding amount can be obtained, so that high-speed welding exceeding 4 [m / min] can be performed in thin plate welding. In multi-layer welding, the number of layers can be reduced and welding can be performed, and the efficiency of welding work can be increased. And since this welding method is a pulse arc welding method, there is little generation | occurrence | production of a spatter and a beautiful bead appearance can be obtained. This welding method can be used for various metals such as steel, stainless steel, and aluminum alloys.
[0003]
[First prior art]
As this welding method, for example, “Twin-Wire GMAW: Process Characteristics and Applications” described on pages 31 to 34 of the May 1999 issue of Welding Journal includes GMAW (gas metal) using two wires. In arc welding), it has been proposed to apply a pulse current shown in FIG. 2 to two wires, and to control so that peak periods of the pulse currents to be supplied to the two wires do not overlap each other. FIG. 4A shows the change over time of the first wire welding current AIw energized to the first welding wire, and FIG. 4B shows the second wire welding current BIw energized to the second welding wire. The time change of is shown. AIp and BIp are the first peak current value and the second peak current value, AIb and BIb are the first base current value and the second base current value, and ATp and BTp are the first peak current energization. Time and second peak current energization time, and ATb and BTb are the first base current energization time and the second base current energization time. In this case, when the first wire welding current AIw energized to the first welding wire is the first base current energization time ATb, the electromagnetic force of the arc of the first welding wire A1 is applied to the arc of the second welding wire B1. It has been shown that the molten pool is stable and a beautiful bead is obtained because it does not have a strong influence.
[0004]
However, in order to improve the welding speed, the wire feed speed and the average welding current value must be increased to increase the amount of melting of the wire. Therefore, when the pulse frequency of the first wire welding current AIw and the second wire welding current BIw becomes dense as shown in FIG. 3 by increasing the pulse frequency in order to increase the average welding current value, the following reason is given. As a result, a large amount of spatter is generated. FIG. 3 is a diagram showing a case where the pulse frequency of the first wire welding current AIw and the second wire welding current BIw becomes dense by increasing the pulse frequency.
When the second peak current BIp of the second wire welding current BIw shown in (B) is energized immediately after the first peak current AIp of the first wire welding current AIw shown in (A) is energized, The droplet detachment of the first welding wire A1 occurs at the time when the first base current AIb that has fallen from the first peak current AIp at the time t2 starts to flow. This time is the time when the second peak current BIp begins to be energized, as shown in FIG. The value of the second peak current BIp is considerably larger than the value of the first base current AIb. Therefore, as shown in FIG. 4, the first arc A3 is attracted to the second arc B3 by the electromagnetic force F acting on the first arc A3. FIG. 4 is a diagram for explaining a state in which the droplet 1 is detached at time t2 shown in FIG. In the figure, when the droplet 1 is detached from the first welding wire A1, the droplet 1 jumps out in the direction of the second welding wire B1, so that it does not fall into the molten pool but becomes spatter.
[0005]
For example, in the case of a mild steel welding wire having a wire diameter of 1.2 [mm], an appropriate pulse condition for performing one pulse / one droplet transfer generally has a peak current value of 450 [A] to 500 [A]. When the peak current application time is 1.5 [ms] to 2.0 [ms] and the peak current value is smaller than 450 [A], the melting energy and the pinch force are insufficient. In this pulse, one pulse is transferred from the tip of the welding wire to n pulse 1 droplet transfer or short circuit transfer. Further, when the peak current value is larger than 500 [A], the melting energy and the pinch force become excessive, and therefore one pulse n droplet in which several droplets are separated from the tip of the welding wire by one pulse. It becomes a transition. In these cases, the occurrence of spatter increases and the arc state becomes unstable.
[0006]
Further, as described on page 240 of the 66th Annual Meeting Summary (2000), the inventor of the present application, the average energization current value of the trailing wire is the average of the first welding wire A1. It was proposed that about 40% of the energization current value is an appropriate value. The reason will be described below.
FIG. 5 is a diagram showing the relationship between the average energization current value [A] (horizontal axis) and the maximum welding speed [m / min] (vertical axis) of the second welding wire B1 in the two-electrode arc welding control method. . The figure shows that the welded material is mild steel, a mild steel wire with a diameter of 1.2 [mm], and argon is 80 [%] and carbon dioxide gas is 20 [%] shielding gas, and the first welding The average energization current value [A] (horizontal axis) and maximum of the second welding wire B1 when welding is performed by changing the average energization current value of the wire A1 to 300 [A], 350 [A], and 400 [A]. The relationship with the welding speed [m / min] (vertical axis) is shown.
Of the above three types of average energization current values, for example, the average energization current value of the first welding wire A1 is 400 [A], and the average energization current value of the second welding wire B1 is 100 [A]. In this case, since the amount of the weld metal formed by the arc B3 of the second welding wire B1 is insufficient, the weld bead is thinned over the entire surface, causing an undercut or flowing behind the molten pool. Since the arc force of the arc B3 of the second welding wire B1 cannot be suppressed in the flowing hot water, a humping bead is generated. Therefore, the maximum welding speed is limited to 2.3 [m / min].
[0007]
Further, when the average energization current value of the second welding wire B1 is increased to 200 [A], the average energization current value of the second welding wire B1 becomes excessive, and therefore the arc B3 of the second welding wire B1. As a result, the molten pool is deeply digged down, the molten metal flow is disturbed, and a large pool is formed between the arcs. This unstable pool accumulates the weld bead shape. Therefore, the maximum welding speed is limited to 3.3 [m / min].
Further, when the average energization current value of the second welding wire B1 is increased to 250 [A], the arc force of the second welding wire B1 becomes further excessive, and the tendency to generate an undercut or a humping bead increases. To do. Therefore, the maximum welding speed at which a normal weld bead can be formed is reduced to 2.2 [m / min].
[0008]
On the other hand, when the average energization current value of the second welding wire B1 is about 150 [A], the arc force of the second welding wire B1 flows backward by the arc force of the first welding wire A1. Since the metal flow is reduced and the surface height of the weld bead is made uniform, the weld bead shape is good even in the case of 4.0 [m / min] high-speed welding.
[0009]
In the same figure, when the average welding current value of the first welding wire A1 is 350 [A], the maximum welding speed is when the average welding current value of the second welding wire B1 is about 130 [A]. It becomes 4.2 [m / min], and the weld bead shape is also good. When the average energization current value of the first welding wire A1 is 300 [A], the maximum welding speed is 3.2 when the average energization current value of the second welding wire B1 is about 120 [A]. [M / min] and the weld bead shape is good.
Thus, in the technique proposed by the present applicant, the ratio of the average conduction current value of the second welding wire B1 and the average conduction current value of the first welding wire A1 is 150/400 = 0.38, Since 130/350 = 0.37 and 120/300 = 0.40, the average conduction current value of the second welding wire B1 is about 40% of the average conduction current value of the first welding wire A1. Sometimes it was possible to form normal weld beads at the highest speed.
[0010]
Therefore, in the waveform of FIG. 3 in which the pulse frequency is increased to increase the average welding current value, an appropriate pulse condition for performing one pulse / one droplet transfer is satisfied, and at the same time, the average value of the second wire welding current BIw is set to When trying to set to about 40% of the average value of the wire welding current AIw, there is the following problem.
For example, in the case of a mild steel welding wire having a wire diameter of 1.2 [mm], the first peak current value AIp is 500 [A], the first peak current conduction time ATp is 2 [ms], and the second peak Since the current value BIp is only 450 [A] and the second peak current conduction time BTp is only about 1.5 [ms], the average current value between the first welding wire A1 and the second welding wire B1 is It becomes substantially the same value, and the condition that the average value of the second wire welding current BIw suitable for high-speed welding is about 40% of the average value of the first wire welding current AIw cannot be satisfied.
[0011]
In addition, since the average current value of the first welding wire A1 and the second welding wire B1 becomes substantially the same value, the average current value per wire is maximum (peak current value + base current value) / 2. Therefore, it is difficult to increase the current required for high-speed welding.
[0012]
In order to solve the above problems, a patent application (Japanese Patent Application No. 2000-228330) (hereinafter referred to as second prior art) was filed on July 28, 2000 by the same applicant as the present applicant.
In order to satisfy the condition that the average value of the second wire welding current BIw suitable for high-speed welding is about 40% of the average value of the first wire welding current AIw, the second welding wire B1 is energized. A method has also been proposed in which the current pulse frequency is set to 1 / n (n is a natural number of 2 or more) of the current pulse frequency applied to the first welding wire A1.
The second conventional multi-electrode pulse arc welding control method and welding apparatus will be described below.
[0013]
[Second prior art]
FIG. 6 is a block diagram showing a circuit configuration of a second conventional multi-electrode pulse arc welding apparatus. As shown in the figure, this welding apparatus includes a first welding power supply device APS, a first wire feeding device AWF, a first feeding speed setting circuit AWS, a second welding power supply device BPS, and a second welding power device APS. It consists of a wire feeder BWF, a second feed speed setting circuit BWS, and a welding torch 4. Hereinafter, these components will be described with reference to FIG.
[0014]
A first contact tip A41 and a second contact tip B41, which are electrically insulated from each other, are mounted on the welding torch 4, and the first welding wire A1 and the second contact tip A41 are passed through these contact tips A41 and B41. The first welding wire B1 is fed and fed to generate the first arc A3 and the second arc B3 between the workpiece 2 and the workpiece 2.
[0015]
The first welding power supply device APS is composed of each circuit block within a range surrounded by a one-dot chain line, and these circuit blocks will be described below.
The output control circuit INV performs output control using a commercial power supply as an input, and supplies an output suitable for the arc load. In general, an inverter control circuit, a chopper control circuit, a thyristor phase control circuit, etc. are commonly used as the output control circuit INV. For example, the above inverter control circuit is formed of the following circuits. In other words, a primary side rectifier circuit that rectifies commercial power, a smoothing circuit that smoothes the rectified ripple voltage, an inverter circuit that converts the smoothed DC voltage into high-frequency alternating current, and high-frequency alternating current suitable for arc loads A high-frequency transformer that steps down the voltage to a predetermined voltage, a secondary side rectifier circuit that rectifies the stepped-down alternating current again, and a direct current reactor that smoothes the rectified rippled direct current. Output control is performed by controlling a plurality of sets of power transistors forming the inverter circuit according to Ei.
[0016]
The voltage detection circuit VD detects the first welding voltage AVw and outputs a voltage detection signal Vd averaged. The voltage setting circuit VS is provided outside the power supply device and outputs a voltage setting signal Vs. The voltage error amplification circuit EV amplifies an error between the voltage detection signal Vd as a feedback signal and the voltage setting signal Vs as a target value, and outputs a voltage error amplification signal Ev. The V / F conversion circuit VF receives the voltage error amplification signal Ev as described above, performs V / F conversion, and outputs a V / F conversion signal Vf. The peak current conduction time setting circuit TP outputs a preset peak current conduction time setting signal Tp. The mono multivibrator MM has the time High level set by the peak current energization time setting signal Tp as a trigger when the V / F conversion signal Vf changes from Low level to High level as described above with reference to FIG. The first pulse period signal ATf is output.
[0017]
The modulation circuit MC surrounded by a dotted line is formed from the voltage error amplification circuit EV, the V / F conversion circuit VF, the peak current conduction time setting circuit TP, and the mono multivibrator MM. The modulation circuit MC receives the voltage detection signal Vd and the voltage setting signal Vs, and outputs the first pulse period signal ATf by pulse frequency modulation control based on an error between the signals.
[0018]
The first peak current setting circuit AIP outputs a preset first peak current setting signal AIp. The first base current setting circuit AIB outputs a preset first base current setting signal AIb. The first switching circuit ASW is connected to the a side when the first pulse period signal ATf is at a high level, and outputs the first peak current setting signal AIp as the first current control setting signal AIsc. When the first pulse period signal ATf is at a low level, the first base current setting signal AIb is output as the first current control setting signal AIsc by being connected to the b side. The current detection circuit ID detects the first wire welding current AIw and outputs a current detection signal Id. The current error amplification circuit EI amplifies an error between the current detection signal Id as a feedback signal and the first current control setting signal AIsc as a target value, and outputs a current error amplification signal Ei. According to the current error amplification signal Ei, the output control circuit INV controls the first wire welding current, and the first welding voltage AVw is applied.
[0019]
The first feed speed setting circuit AWS is provided outside the power supply device and outputs a first feed speed setting signal AWs. The feed control circuit WC receives the first feed speed setting signal AWs and outputs a feed control signal Wc. The first wire feeder AWF controls the feeding of the first welding wire A1 in accordance with the feeding control signal Wc.
[0020]
Next, each circuit block constituting the second welding power supply device BPS will be described.
The magnification setting circuit NS outputs a magnification setting signal n which is an integer of 1 or more. The period conversion circuit TC receives the first pulse period signal ATf output from the first welding power source device APS and the magnification setting signal n as input, and synchronizes with the first pulse period signal ATf, and The signal is converted into a signal having a period n times that of the signal, and a second pulse period signal BTf is output.
[0021]
The second switching circuit BSW is connected to the a side when the second pulse cycle signal BTf is at the High level, and outputs the second peak current setting signal BIp as the second current control setting signal BIsc. When the second pulse period signal BTf is at the low level, the second base current setting signal BIb is output as the second current control setting signal BIsc by being connected to the b side. The current error amplification circuit EI amplifies an error between the current detection signal Id that is a feedback signal and the second current control setting signal BIsc that is a target value, and outputs a current error amplification signal Ei. The output control circuit INV controls the second wire welding current in accordance with the current error amplification signal Ei, and the second welding voltage BVw is applied.
[0022]
For the explanation of the other symbols, the first welding voltage AVw and the first wire welding current AIw are changed to the second welding voltage BVw and the second wire welding current BIw, the first peak current setting circuit AIP and the first The peak current setting signal AIp is set to the second peak current setting circuit BIP and the second peak current setting signal BIp, and the first base current setting circuit AIB and the first base current setting signal AIb are set to the second base current setting. The first switching circuit ASW and the first current control setting signal AIsc are sent to the second switching circuit BSW and the second current control setting signal BIsc to the first transmission circuit BIB and the second base current setting signal BIb. The feed speed setting circuit AWS and the first feed speed setting signal AWSs are changed to the second feed speed setting circuit BWS and the second feed speed setting signal BWs, and the first wire feeding device AWF. Is replaced with the second wire feeder BWF, and the description thereof will be omitted.
As a result, the second welding voltage BVw is applied by the second welding power source device BPS, and the second welding wire B1 is fed by the second wire feeding device BWF. A second arc B3 is generated between the object 2 and the second wire welding current BIw is energized.
[0023]
Further, in the second conventional multi-electrode pulse arc welding apparatus shown in FIG. 6, the welding current and welding voltage waveforms in the case of the magnification setting signal n = 1 output from the magnification setting circuit NS are shown in FIG. FIG. 8 shows waveforms of the welding current and the welding voltage when the magnification setting signal n = 2. Comparing FIG. 7 and FIG. 8, by setting the magnification setting signal n = 2, the average welding current applied to the succeeding wire can be reduced to about 40% of the average welding current applied to the preceding wire. it can. The droplet transfer phenomenon in this case will be described with reference to FIGS. As shown in FIG. 9, the first peak current AIp and the second peak current BIp are respectively supplied to the first welding wire A1 and the second welding wire B1 during the period from time t2 to time t4. During the period in which the first peak current AIp and the second peak current BIp are applied, the current value is large, so that the first arc A3 and the second arc are shown in FIG. B3 is generated in the feeding direction of the first welding wire A1 and the second welding wire B1. Therefore, one arc is not pulled in the direction of the other arc, and stable arc length control can be performed.
Further, droplet detachment from the first welding wire A1 and the second welding wire B1 occurs near time t5 shown in FIG. 9, and the first base current AIb and the second base current with the least magnetic interference of the arc are generated. Since the droplet detachment occurs at a time close to the energization period of the base current BIb, as shown in FIG. 11, the droplet 1 falls into the molten pool, and the generation of spatter can be significantly reduced.
[0024]
Further, in the welding method in which the first wire welding current AIw and the second wire welding current BIw are simultaneously supplied to the first welding wire A1 and the second welding wire B1 of the second prior art, the magnification setting circuit NS includes The second wire suitable for high-speed welding is obtained by setting the output frequency setting signal n to 1 / n the pulse frequency of the pulse current applied to the first welding wire A1 to the pulse frequency of the pulse current applied to the second welding wire B1. The condition that the average value of the welding current BIw is approximately 40 [%] of the average value of the first wire welding current AIw can be satisfied.
[0025]
[Problems to be solved by the invention]
However, in the second prior art, the arc length control of the first welding wire A1 is performed by pulse frequency modulation by feeding back the first welding voltage AVw. On the other hand, the second wire welding current BIw energized to the second welding wire B1 merely changes in synchronization with the pulse frequency of the first wire welding current AIw, and the second welding voltage BVw is changed. Since the feedback is not performed, the arc length control of the second welding wire B1 is not performed. Therefore, when the torch vibrates during welding or there are irregularities on the weld line of the work piece 2, the arc length of the first welding wire A1 can be controlled, but the arc length of the second welding wire B1 can be controlled. A beautiful weld bead cannot be formed because of insufficient control.
[0026]
[Means for Solving the Problems]
[0028]
The invention described in claim 1 is the second embodiment shown in FIG. 15, wherein the first and second welding wires A1 and B1 are made to have the same peak current and base current energization period, respectively. This is a case where the pulse frequency of the pulse current applied to the welding wire B1 is set to 1 / n of the pulse frequency applied to the first welding wire A1, and n = 2.
  A first welding wire A1 and a second welding wire B1 that are electrically insulated from each other from one welding torch 4 are fed at a preset feeding speed, and the first welding wire A1 is preset. The energization of the first peak current AIp and the energization of the first base current AIb set in advance are repeated as one cycle, and the second peak voltage BVp set in advance is applied to the second welding wire B1. Energization of the second peak current BIp by the application of the second and energization of the second base current BIb by the application of the second base voltage BVb is repeated for one cycle, and the first welding wire A1 and the second welding current A2 are repeated. In the multi-electrode pulse arc welding control method of generating and welding two arcs A3 and B3 between the welding wire B1 and the work piece 2
  The second peak current BIp is applied to the second welding wire B1 by applying the second peak voltage BVp during the first energization period of the first peak current AIp,
  In the energization period of the first base current AIb, the second base voltage BVb is applied to apply the second base current BIb,
  Subsequently, in the second energizing period of the first peak current AIp and the energizing period of the first base current AIb, the second base current BIb is energized by applying the second base voltage BVb,
  Further, the energization similar to the second time is repeated up to the n-th time by a magnification n which is a preset integer of 2 or more, and the first to n-th current energization is repeated as one set and energized.
  First pulse voltage time ATp is determined in advance, and the pulse frequency of first wire welding current AIW is changed so that the average value of first welding voltage AVw is equal to first predetermined voltage setting value AVs. To control the arc length of the first welding wire A1,
By controlling the second peak voltage to be equal to a predetermined peak voltage setting value, the arc length of the second welding wire B1 during the application period of the second peak voltage is controlled, and the second peak voltage is controlled. A multi-electrode pulse arc for controlling the arc length of the second welding wire B1 during the application period of the second base voltage by controlling the base voltage of 2 to be equal to a predetermined base voltage set value. It is a welding control method.
[0029]
Invention of Claim 2 is Example 3 shown in FIG. 16, Comprising: It is a case where the pulse of 1st peak current conduction period ATp and 2nd peak current conduction period BTp is complete | finished simultaneously,
  A first welding wire A1 and a second welding wire B1 that are electrically insulated from each other from one welding torch 4 are fed at a preset feeding speed, and the first welding wire A1 is preset. The energization of the first peak current AIp and the energization of the first base current AIb set in advance are repeated as one cycle, and the second peak voltage BVp set in advance is applied to the second welding wire B1. Energization of the second peak current BIp by the application of the second and energization of the second base current BIb by the application of the second base voltage BVb is repeated for one cycle, and the first welding wire A1 and the second welding current A2 are repeated. In the multi-electrode pulse arc welding control method of generating and welding two arcs A3 and B3 between the welding wire B1 and the work piece 2
  The second base voltage BVb is applied to the second welding wire B1 during the period from the start of the energization period of the first peak current AIp to the elapse of a preset delay time Tod. Energize the base current BIb,
  During the period from the elapsed time to the end of the energization period of the first peak current AIp, the second peak current BIp is energized by applying the second peak voltage BVp,
  In the energization period of the first base current AIb, the second base voltage BVb is applied to apply the second base current BIb,
  First pulse voltage time ATp is determined in advance, and the pulse frequency of first wire welding current AIW is changed so that the average value of first welding voltage AVw is equal to first predetermined voltage setting value AVs. To control the arc length of the first welding wire A1,
By controlling the second peak voltage to be equal to a predetermined peak voltage setting value, the arc length of the second welding wire B1 during the application period of the second peak voltage is controlled, and the second peak voltage is controlled. A multi-electrode pulse arc for controlling the arc length of the second welding wire B1 during the application period of the second base voltage by controlling the base voltage of 2 to be equal to a predetermined base voltage set value. It is a welding control method.
[0030]
The invention according to claim 3 is the fourth embodiment shown in FIG. 17, wherein the pulses of the first peak current conduction period ATp and the second peak current conduction period BTp are simultaneously terminated to produce the second welding wire. The pulse frequency of the pulse current energized to B1 is 1 / n of the pulse frequency energized to the first welding wire A1, and n = 2,
  A first welding wire A1 and a second welding wire B1 that are electrically insulated from each other from one welding torch 4 are fed at a preset feeding speed, and the first welding wire A1 is preset. The energization of the first peak current AIp and the energization of the first base current AIb set in advance are repeated as one cycle, and the second peak voltage BVp set in advance is applied to the second welding wire B1. Energization of the second peak current BIp by the application of the second and energization of the second base current BIb by the application of the second base voltage BVb is repeated for one cycle, and the first welding wire A1 and the second welding current A2 are repeated. In the multi-electrode pulse arc welding control method of generating and welding two arcs A3 and B3 between the welding wire B1 and the work piece 2
  The second base voltage BVb set in advance is applied to the second welding wire B1 during a period from the start of the first energization period of the first peak current AIp to the elapse of a preset delay time Tod. To apply the second base current BIb,
  During the period from the elapsed time to the end of the energization period of the first peak current AIp, the second peak current BIp is energized by applying the second peak voltage BVp,
  In the energization period of the first base current AIb, the second base voltage BVb is applied to apply the second base current BIb,
  Subsequently, in the second energizing period of the first peak current AIp and the energizing period of the first base current AIb, the second base current BIb is energized by applying the second base voltage BVb,
  Further, the energization similar to the second time is repeated up to the n-th time by a magnification n which is a preset integer of 2 or more, and the first to n-th current energization is repeated as one set and energized.
  First pulse voltage time ATp is determined in advance, and the pulse frequency of first wire welding current AIW is changed so that the average value of first welding voltage AVw is equal to first predetermined voltage setting value AVs. To control the arc length of the first welding wire A1,
By controlling the second peak voltage to be equal to a predetermined peak voltage setting value, the arc length of the second welding wire B1 during the application period of the second peak voltage is controlled, and the second peak voltage is controlled. A multi-electrode pulse arc for controlling the arc length of the second welding wire B1 during the application period of the second base voltage by controlling the base voltage of 2 to be equal to a predetermined base voltage set value. It is a welding control method.
[0031]
As shown in FIG. 18, the invention according to claim 4
  A first welding wire A1 and a second welding wire B1 that are electrically insulated from each other from one welding torch 4 are fed at a preset feeding speed, and the first welding wire A1 is preset. The energization of the first peak current AIp and the energization of the first base current AIb set in advance are repeated as one cycle, and the second peak voltage BVp set in advance is applied to the second welding wire B1. Energization of the second peak current BIp by the application of the second and energization of the second base current BIb by the application of the second base voltage BVb is repeated for one cycle, and the first welding wire A1 and the second welding current A2 are repeated. In the multi-electrode pulse arc welding apparatus that generates and welds two arcs A3 and B3 between the welding wire B1 and the work piece 2;
  A voltage detection circuit VD that detects a first welding voltage AVw between the first welding wire A1 and the workpiece 2 and outputs a voltage detection signal Vd;
  A voltage setting circuit VS that outputs a voltage setting signal Vs;
  A modulation circuit MC that receives the voltage detection signal Vd and the voltage setting signal Vs as inputs and outputs a first pulse period signal ATf by pulse frequency modulation control based on an error between the signals;
  A first peak current setting circuit AIP that outputs a first peak current setting signal AIp;
  A first base current setting circuit AIB for outputting a first base current setting signal AIb;
  The first pulse period signal ATf, the first peak current setting signal AIp, and the first base current setting signal AIb as inputs, and the first peak current setting signal AIp according to the first pulse period signal ATf. And a first switching circuit ASW that switches between the first base current setting signal AIb and outputs it as the first current control setting signal AIsc.
  A first welding power supply device APS for controlling the first wire welding current AIw by the first current control setting signal AIsc;
  A magnification setting circuit NS that outputs a magnification setting signal n that is an integer of 2 or more;
  A period conversion circuit TC that receives the first pulse period signal ATf as an input, converts it into a signal that is synchronized with the signal and has a period of the magnification setting signal n times the signal, and outputs a second pulse period signal BTf; ,
  A delay time setting circuit TOD that outputs a delay time setting signal Tod;
  With the second pulse period signal BTf and the delay time setting signal Tod as inputs, a low level period determined by the delay time setting signal Tod from the time when the second pulse period signal BTf changes from Low level to High level. A delay circuit OD that outputs a delay signal Od
  A logical product circuit AND that performs a logical product (AND) of the second pulse period signal BTf and the delayed signal Od and outputs a switching signal Ad;
  A peak voltage setting circuit BVP that outputs a peak voltage setting signal BVp;
  A base voltage setting circuit BVB that outputs a base voltage setting signal BVb;
  The switching signal Ad, the peak voltage setting signal BVp, and the base voltage setting signal BVb are input, and the switching signal Ad is used to switch the peak voltage setting signal BVp and the base voltage setting signal BVb as a voltage control setting signal BVsc. A second switching circuit BSW for outputting;
  A second voltage detection circuit BVD that detects a second welding voltage BVw between the second welding wire B1 and the workpiece 2 and outputs a second voltage detection signal BVd;
  A voltage error amplification circuit EV that receives the second voltage detection signal BVd and the voltage control setting signal BVsc and outputs a voltage error amplification signal Ev;
  This is a multi-electrode pulse arc welding apparatus composed of a second welding power source BPS that controls the second welding voltage BVw by the voltage error amplification signal Ev.
[0032]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a diagram that best represents the features of the invention according to the present application. Since this is the same as FIG. 18 described later, the description will be described later with reference to FIG.
The embodiment of the invention is a multi-electrode pulse arc welding apparatus according to claim 5 at the time of filing, wherein the first welding wire A1 and the second welding wire A1 electrically insulated from each other from one welding torch 4 are used. The welding wire B1 is fed at a preset feeding speed, and the first welding wire A1 is energized with a preset first peak current AIp and a preset first base current AIb. While repeating energization for one cycle, the second welding wire B1 is energized with a second peak current BIp by applying a preset second peak voltage BVp and second by applying a second base voltage BVb. The base current BIb is energized repeatedly for one cycle, and two arcs A3 and B3 are generated between the first welding wire A1 and the second welding wire B1 and the workpiece 2 to be welded. In a multi-electrode pulse arc welding apparatus in contact, a voltage detection circuit VD that detects the first welding voltage AVw between the first welding wire A1 and the workpiece 2 and outputs a voltage detection signal Vd, and a voltage setting A voltage setting circuit VS that outputs a signal Vs, and a modulation circuit MC that receives the voltage detection signal Vd and the voltage setting signal Vs as inputs and outputs a first pulse period signal ATf by pulse frequency modulation control based on an error between the signals. A first peak current setting circuit AIP that outputs a first peak current setting signal AIp, a first base current setting circuit AIB that outputs a first base current setting signal AIb, and the first pulse period The signal ATf, the first peak current setting signal AIp, and the first base current setting signal AIb are input to the first pulse period signal ATf. Therefore, the first peak current setting signal AIp and the first base current setting signal AIb are switched to output the first current control setting signal AIsc and output as the first current control setting signal AIsc. A first welding power supply device APS that controls the first wire welding current AIw by a control setting signal AIsc, a magnification setting circuit NS that outputs a magnification setting signal n that is an integer of 2 or more, and the first pulse period signal ATf Is input to the period conversion circuit TC that outputs the second pulse period signal BTf by converting the signal into a signal having the period of the magnification setting signal n times that of the signal and outputting the delay time setting signal Tod The second pulse period signal BTf is inputted with the delay time setting circuit TOD, the second pulse period signal BTf and the delay time setting signal Tod as inputs. A logical product of a delay circuit OD that outputs a delay signal Od that is Low level for a period determined by the delay time setting signal Tod from the time when the ow level changes to High level, and the second pulse period signal BTf and the delay signal Od AND circuit that performs (AND) and outputs switching signal Ad, peak voltage setting circuit BVP that outputs peak voltage setting signal BVp, base voltage setting circuit BVB that outputs base voltage setting signal BVb, and the switching signal First, Ad, the peak voltage setting signal BVp, and the base voltage setting signal BVb are input, and the peak voltage setting signal BVp and the base voltage setting signal BVb are switched by the switching signal Ad and output as a voltage control setting signal BVsc. 2 switching circuit BSW, and by the voltage control setting signal BVsc A multi-electrode pulse arc welding device and a second welding power supply BPS for controlling the second welding voltage BVW.
[0033]
【Example】
[Example 1]
FIG. 12 is a diagram showing a welding current of the multi-electrode pulse arc welding control method according to the first embodiment corresponding to the invention of claim 1 at the time of filing, and FIG. 12 (A) shows the time change of the first wire welding current AIw. FIG. 4B shows the time change of the second wire welding current BIw. A circuit configuration of a welding apparatus for carrying out the multi-electrode pulse arc welding control method of the first embodiment is shown in FIG. 18 and will be described later.
In FIG. 12, for the first welding wire A1, the arc length of the first welding wire A1 is increased or decreased by changing the pulse frequency of the first wire welding current AIw to increase or decrease the average value of the first wire welding current AIw. Control. Further, for the second welding wire B1, the second pulse period BTf and the second peak current conduction time BTp are set to the first pulse period ATf and the first peak current conduction time ATp of the first wire welding current AIw. The arc length of the second welding wire B1 is controlled by changing the value of the second peak current BIp of the second wire welding current BIw to increase or decrease the average value of the second wire welding current BIw.
[0034]
Here, with reference to FIG. 13, it will be described that the arc length is controlled to be constant by changing the pulse frequency of the first wire welding current AIw shown in FIG. An explanation will be given of controlling the arc length to be constant by changing the value of the second peak current BIp of the wire welding current BIw.
[0035]
FIG. 13 is a diagram for explaining that the arc length is controlled to be constant by changing the pulse frequency of the first wire welding current AIw shown in FIG. 12 (A). This will be described with reference to voltage waveform diagrams. In the figure, the time at which the next pulse is generated is obtained in order to bring the average value of the actual voltage waveform closer to the first voltage setting value AVs starting from time t1. Here, the relationship among the first peak voltage AVp, the first peak voltage time ATp, the first base voltage AVb, and the first base voltage time ATb is expressed by the following equation (1).
AVs × (ATp + ATb) = AVp × ATp + AVb × ATb (1)
It is assumed that the first peak voltage time ATp and the first voltage set value AVs are set in advance.
When the first base voltage time ATb is obtained from this equation (1), equation (2) is obtained.
ATb = ATp × (AVp−AVs) / (AVs−AVb) (2)
The state in which the arc length is increased is that the values of the first peak voltage AVp and the first base voltage AVb are increased. In this case, (AVp−AVs) on the right side of Equation (2) increases and (AVs−AVb) decreases. Therefore, the first base voltage time ATb is increased. The increase in the first base voltage time ATb delays the time for generating the next pulse.
[0036]
Next, based on the above relationship, the time change of the first wire welding current AIw shown in FIG. It is assumed that the welding wire feeding speed of the first welding wire A1 and the welding wire melting amount are balanced during the period from time t1 to time t2.
In the period from time t2 to time t3, when the distance between the contact tip and the workpiece is changed due to, for example, the processing accuracy and positioning accuracy of the workpiece, the first base current energizing time is shortened. ATb becomes ATb2 shorter than ATb1 in the period from time t1 to time t2, and a pulse is generated at time t3.
Next, during the period from time t3 to t4, when the distance between the contact tip and the workpiece is fluctuated and the arc length is increased, the first base current energization time ATb is increased to ATb3, and at time t4, A pulse is generated.
Then, from time t4 to t5, the first wire welding current AIw and the second wire welding current BIw having the same pulse period as the period from time t1 to t2 described above are energized.
[0037]
FIG. 14 is a diagram for explaining that the arc length is controlled to be constant by controlling the second peak voltage to be equal to a predetermined peak voltage setting value during the application period of the second peak voltage. The second peak current BIp [A] (horizontal axis) and the second peak voltage BVp [V when the arc length, which is the distance from the tip of the second welding wire B1 to the work piece 2, changes. ] (Vertical axis).
  During the period from time t1 to time t2 shown in FIG. 12, BIp2 is energized as the second peak current BIp shown in FIG. 14, and the welding wire feed speed of the second welding wire B1 and the welding wire melting amount are balanced, The arc length L at this time is L2.
  Since the first welding wire A1 and the second welding wire B1 are integral with the welding torch 4, during the period from time t2 to t3 shown in FIG. 12, similarly to the first welding wire A1 described above. The distance between the contact tip and the workpiece is changed, and the arc length L is shortened to L3 shown in FIG.
  At this time, the second peak current energization time BTp is controlled so that the second peak voltage becomes equal to a predetermined peak voltage setting value. As shown in FIG. Shows a straight shoulder. As a result, when the arc length L is shortened to L3, the second peak voltage BVp is lowered, and the intersection of the straight line of the peak setting voltage 2 and the arc length L curve moves to the right. Then, the second peak current BIp increases to BIp3, and the second peak current BIp energized at time t3 shown in FIG. 12 increases. Accordingly, the melting rate of the second welding wire B1 increases and the arc length L returns to L2.
  Next, during the period from time t3 to time t4 shown in FIG. 12, the distance between the contact tip and the workpiece is fluctuated, the arc length L becomes long, and when it becomes L1 shown in FIG. As the voltage BVp increases, the intersection of the straight line of the peak voltage set value and the curve of the arc length L moves to the left. Then, the second peak current BIp decreases to BIp1, and the second peak current BIp that is energized at time t4 shown in FIG. 12 decreases. Therefore, the melting rate of the second welding wire B1 decreases and the arc length returns to L2.
  Then, at time t4 to t5 shown in FIG. 12, the second welding current BIw having the same pulse period as that of the above-described period from time t1 to t2 is energized. Similarly to the above, during the application period of the second base voltage,The arc length is controlled to be constant by controlling the second base voltage to be equal to a predetermined second base setting voltage.
[0038]
Therefore, in Example 1,
(1) By controlling the arc length of the second welding wire B1 using the pulse peak modulation method by feeding back the second welding voltage, the arc length control of the second welding wire B1 can be performed more stably. it can.
(2) By ending the pulses of the first peak current energizing period ATp and the second peak current energizing period BTp simultaneously, the droplet detachment between the first welding wire A1 and the second welding wire B1 is arced. The base current can be applied in a period with little magnetic interference, and the occurrence of sputtering can be reduced.
[0039]
[Example 2]
FIG. 15 is a diagram showing a welding current of the multi-electrode pulse arc welding control method according to the second embodiment corresponding to the invention of claim 2 at the time of filing, and FIG. FIG. 4B shows the time change of the second wire welding current BIw. Further, a circuit configuration of a welding apparatus for carrying out the multi-electrode pulse arc welding control method of Example 2 is shown in FIG. 18 and will be described later.
In the figure, Example 2 is the same as Example 1 above, except that the pulse frequency of the pulse current applied to the second welding wire B1 is set to 1 / n of the pulse frequency applied to the first welding wire A1. The figure is for n = 2. Therefore, the second pulse cycle BTf of the second wire welding current BIw shown in FIG. 5B is twice as long as the first pulse cycle ATf of the first wire welding current AIw shown in FIG. Become. Therefore, the condition that the average value of the second wire welding current BIw suitable for high-speed welding is about 40% of the average value of the first wire welding current AIw can be satisfied, and the efficiency of the welding operation can be improved. Can do.
[0040]
[Example 3]
FIG. 16 is a diagram showing the welding current of the multi-electrode pulse arc welding control method of the third embodiment corresponding to the invention of claim 3 at the time of filing, and FIG. FIG. 4B shows the time change of the second wire welding current BIw. Further, a circuit configuration of a welding apparatus for carrying out the multi-electrode pulse arc welding control method of Example 2 is shown in FIG. 18 and will be described later.
[0041]
In the figure, Example 3 is the same as Example 1 described above, except that the peak current conduction period BTp of the second wire welding current BIw is shorter than the peak current conduction period ATp of the first wire welding current AIw.
(1) By controlling the arc length of the second welding wire B1 using the pulse peak modulation method by feeding back the second welding voltage, the arc length control of the second welding wire B1 can be performed more stably. it can.
(2) By ending the pulses of the first peak current energizing period ATp and the second peak current energizing period BTp simultaneously, the droplet detachment between the first welding wire A1 and the second welding wire B1 is arced. The base current can be applied in a period with little magnetic interference, and the occurrence of sputtering can be reduced.
(3) Since the peak current conduction period BTp of the second wire welding current BIw can be set to a value different from the peak current conduction period ATp of the first wire welding current AIw, it can be used for welding under various conditions. it can.
[0042]
[Example 4]
FIG. 17 is a diagram showing the welding current of the multi-electrode pulse arc welding control method of Example 4 corresponding to the invention of claim 4 at the time of filing, and FIG. 17 (A) shows the time change of the first wire welding current AIw. FIG. 4B shows the time change of the second wire welding current BIw. Further, a circuit configuration of a welding apparatus for carrying out the multi-electrode pulse arc welding control method of Example 2 is shown in FIG. 18 and will be described later.
[0043]
In the figure, Example 4 is the same as Example 3 described above except that the pulse frequency of the pulse current applied to the second welding wire B1 is set to 1 / n of the pulse frequency applied to the first welding wire A1. The figure is for n = 2. Therefore, the second pulse cycle BTf of the second wire welding current BIw shown in FIG. 5B is twice as long as the first pulse cycle ATf of the first wire welding current AIw shown in FIG. Become. Therefore, the condition that the average value of the second wire welding current BIw suitable for high-speed welding is about 40% of the average value of the first wire welding current AIw can be satisfied, and the efficiency of the welding operation can be improved. Can do.
[0044]
FIG. 18 is a block diagram showing a circuit configuration of a welding apparatus for carrying out the multi-electrode pulse arc welding control method according to the first to fourth embodiments. In the same figure, the same circuit blocks as those in FIG. 6 described above are denoted by the same reference numerals, and description thereof is omitted. Hereinafter, the delay time setting circuit TOD, the delay circuit OD, the AND circuit AND, the base voltage setting circuit BVB, the peak voltage setting circuit BVP, and the voltage error detection circuit EV, which are circuit blocks different from those in FIG. I will explain.
[0045]
The delay time setting circuit TOD outputs a delay time setting signal Tod. The delay circuit OD uses the second pulse cycle signal BTf, which has a cycle obtained by multiplying the cycle of the first pulse cycle signal ATf by n, as a trigger to set the above delay time from that point. A delay signal Od that is Low level for a period determined by the signal Tod is output. The AND circuit AND performs a logical product (AND) of the second pulse period signal BTf and the delay signal Od, and outputs a switching signal Ad.
The first embodiment shown in FIG. 12 is a case where the delay time setting signal Tod is zero and the magnification setting signal n = 1, and the second embodiment shown in FIG. 15 is that the delay time setting signal Tod is zero and the magnification is This is a case where the setting signal n = 2. Further, the third embodiment shown in FIG. 16 is a case where the magnification setting signal n = 1, and the fourth embodiment shown in FIG. 17 is a case where the magnification setting signal n = 2.
In FIG. 18, the magnification setting circuit NS and the delay time setting circuit TOD are in the second welding power supply device. However, these circuits may be provided outside the power supply device. Further, the magnification setting signal n and the delay time setting signal Tod may be set by a communication signal from the welding robot control device.
[0046]
  The peak voltage setting circuit BVP outputs a preset peak voltage setting signal BVp. The base voltage setting circuit BVB outputs a preset base voltage setting signal BVb. The second switching circuit BSW is connected to the a side when the switching signal Ad is at a high level, and outputs the peak voltage setting signal BVp as the voltage control setting signal BVsc. Further, when the switching signal Ad is at the low level, it is connected to the b side and outputs the base voltage setting signal BVb as the voltage control setting signal BVsc. The second voltage detection circuit BVD detects a second welding voltage BVw between the second welding wire B1 and the workpiece 2 and outputs a second voltage detection signal BVd. The voltage error amplification circuit EV amplifies an error between the second voltage detection signal BVd as a feedback signal and the voltage control setting signal BVsc as a target value, and outputs a voltage error amplification signal Ev. Output control by the output control circuit INV is performed according to the voltage error amplification signal Ev, and the second welding voltage BVw is applied.
[0047]
In the welding apparatus for carrying out the first to fourth embodiments described above,
(1) The arc length control of the second welding wire B1 can be performed by a pulse peak modulation method,
(2) The pulses of the first peak current conduction period ATp and the second peak current conduction period BTp can be terminated simultaneously,
(3) The peak current conduction period BTp of the second wire welding current BIw can be set to a value different from the peak current conduction period ATp of the first wire welding current AIw.
(4) Since the pulse frequency of the pulse current energized to the second welding wire B1 can be reduced to 1 / n of the pulse frequency energized to the first welding wire A1, the following effects are provided.
[0048]
【The invention's effect】
The multi-electrode pulse arc welding control method and welding apparatus of the present invention have the following effects.
(1) Instability of the arc generation state such as deformation of the arc shape caused by mutual interference between the two arcs and fluctuation of the arc length can be suppressed, and good welding quality can always be obtained.
(2) By performing the arc length control of the second welding wire B1 by the pulse peak modulation method, the arc length control of the second welding wire B1 can be performed more stably.
(3) By simultaneously ending the pulses of the first peak current energizing period ATp and the second peak current energizing period BTp, the droplet detachment between the first welding wire A1 and the second welding wire B1 is arced. It can be performed in a base current conduction period with little magnetic interference.
(4) By making the energization period BTp of the second peak current BIp different from the energization period ATp of the first peak current, it can be used for welding under various conditions.
(5) By setting the pulse frequency of the pulse current applied to the second welding wire B1 to 1 / n of the pulse frequency applied to the first welding wire A1, the second wire welding current BIw suitable for high-speed welding The condition that the average value is about 40 [%] of the average value of the first wire welding current AIw can be satisfied, and the efficiency of the welding operation can be improved.
[Brief description of the drawings]
FIG. 1 is a diagram that best represents the features of the invention according to the present application;
FIG. 2 is a diagram illustrating a pulse current for explaining that control is performed by energizing two wires according to the prior art 1 so that peak periods of the respective pulse currents do not overlap each other.
FIG. 3 is a diagram showing a case where the pulse frequency of the first wire welding current AIw and the second wire welding current BIw becomes dense by increasing the pulse frequency of the prior art 1;
4 is a diagram for explaining a state in which the droplet 1 is detached at time t2 shown in FIG. 3. FIG.
FIG. 5 shows a consumable electrode gas shielded arc with a shield gas of argon [80] and carbon dioxide [20] using mild steel wire with a diameter of 1.2 [mm] to be welded. It is a figure which shows the relationship between the average energization electric current value [A] (horizontal axis) and the maximum welding speed [m / min] (vertical axis) of 2nd welding wire B1 when a welding control method is implemented.
FIG. 6 is a block diagram showing a circuit configuration of a second conventional multi-electrode pulse arc welding apparatus.
7 is a diagram showing waveforms of a welding current and a welding voltage when a magnification setting signal n = 1 output from a magnification setting circuit NS in the second conventional multi-electrode pulse arc welding apparatus shown in FIG. 6; is there.
8 is a diagram showing waveforms of a welding current and a welding voltage when a magnification setting signal n = 2 output from a magnification setting circuit NS in the second conventional multi-electrode pulse arc welding apparatus shown in FIG. 6; is there.
9 is a diagram showing a detailed waveform of a welding current when a magnification setting signal n = 2 output from a magnification setting circuit NS in the second conventional multi-electrode pulse arc welding apparatus shown in FIG. 6; .
10 is a diagram showing an arc generation state when the magnification setting signal n = 2 output from the magnification setting circuit NS in the second conventional multi-electrode pulse arc welding apparatus shown in FIG. 6. FIG.
11 is a diagram showing droplet transfer when the magnification setting signal n = 2 output from the magnification setting circuit NS in the second conventional multi-electrode pulse arc welding apparatus shown in FIG. 6;
FIG. 12 is a diagram showing a welding current and a welding voltage of the multi-electrode pulse arc welding control method of the first embodiment corresponding to the invention of claim 1 at the time of filing.
FIG. 13 is a diagram for explaining that the arc length is controlled to be constant by changing the pulse frequency of the first wire welding current AIw shown in FIG. 12 (A).
FIG. 14 shows the relationship between the second wire welding current BIw [A] (horizontal axis) and the second welding voltage BVw [V] (vertical axis) when the arc length of the second welding wire B1 changes. FIG.
FIG. 15 is a diagram showing a welding current and a welding voltage of the multi-electrode pulse arc welding control method of Example 2 corresponding to the invention of claim 2 at the time of filing.
FIG. 16 is a diagram showing a welding current and a welding voltage of the multi-electrode pulse arc welding control method according to the third embodiment corresponding to the invention of claim 3 at the time of filing;
FIG. 17 is a diagram showing a welding current and a welding voltage of the multi-electrode pulse arc welding control method of embodiment 4 corresponding to the invention of claim 4 at the time of filing.
FIG. 18 is a block diagram illustrating a circuit configuration of a welding apparatus for carrying out the multi-electrode pulse arc welding control method according to the first to fourth embodiments.
[Explanation of symbols]
  1 droplet
  2 Workpiece
  4 Welding torch
  A1 first welding wire
  A3 First arc
  A41 First contact chip
  Ad switching signal
  AIB first base current setting circuit
  AIb first base current, first base current setting signal
  AIP first peak current setting circuit
  AIp first peak current, first peak current setting signal
  AIsc first current control setting signal
  AIw 1st wire welding current
  AND AND circuit
  APS first welding power source
  ASW first switching circuit
  ATf first pulse period, first pulse period signal
  ATb first base current conduction time (first base voltage time)
  ATp first peak current conduction time (first peak voltage time)
  AVb first base voltage
  AVp first peak voltage
  AVw 1st welding voltage
  AWF first wire feeder
  AWS First feed speed setting circuit
  AWs First feed speed setting signal
  B1 Second welding wire
  B3 Second arc
  B41 Second contact chip
  BIB second base current setting circuit
  BIb second base current, second base current setting signal
  BIP second peak current setting circuit
  BIp second peak current, second peak current setting signal
  BIsc second current control setting signal
  BIw Second wire welding current
  BPS second welding power supply
  BSW second switching circuit
  BTf Second pulse period, second pulse period signal
  BTp Second peak current conduction time
  BVb second base voltage
  BVD second voltage detection circuit
  BVd second voltage detection signal
  BVp second peak voltage
  BVsc voltage control setting signal
  BVw Second welding voltage
  BWF Second wire feeder
  BWS Second feed speed setting circuit
  BWs Second feed speed setting signal
  EI current error amplifier circuit
  Ei Current error amplification signal
  EV voltage error amplifier circuit
  Ev Voltage error amplification signal
  F Electromagnetic force
  ID current detection circuit
  Id Current detection signal
  INV output control circuit
  L Arc length
  MC modulation circuit
  MM mono multivibrator
  NS magnification setting circuit
  n Magnification, magnification setting signal
  OD delay circuit
  Od Delay signal
  TC period conversion circuit
  TOD delay time setting circuit
  Tod delay time setting signal
  TP peak current conduction time setting circuit
  Tp Peak current conduction time setting signal
  VD voltage detection circuit
  Vd Voltage detection signal
  VF V / F conversion circuit
  Vf V / F conversion signal
  VS first voltage setting circuit
  Vs first voltage setting signal
  WC feed control circuit
  Wc Feed control signal

Claims (4)

A first welding wire and a second welding wire, which are electrically insulated from each other from one welding torch, are fed at a preset feeding speed, respectively, and a first preset wire is supplied to the first welding wire. Repeating energization with one cycle of energization of the peak current and energization of the first base current set in advance, and the second peak current by applying the preset second peak voltage to the second welding wire And energizing the second base current by applying the second base voltage are repeated one cycle, and 2 between the first welding wire and the second welding wire and the work piece. In a multi-electrode pulse arc welding control method for generating and welding two arcs,
During the first energization period of the first peak current, the second peak current is applied to the second welding wire to energize the second peak current, and the first base current is energized. During the period, the second base voltage is applied to apply the second base current, and the second peak current supply period and the first base current supply period are the second time. Applying a base voltage of 2 to pass the second base current;
Further, the energization similar to the second time is repeated up to the n-th time by a magnification n which is a preset integer of 2 or more, and the first to n-th current energization is repeated as one set and energized.
The first peak voltage time is determined in advance, and the pulse frequency of the first wire welding current is changed so that the average value of the first welding voltage becomes equal to the predetermined first voltage setting value. Control the arc length of 1 welding wire,
The arc length of the second welding wire is controlled during the application period of the second peak voltage by controlling the second peak voltage to be equal to a predetermined peak voltage setting value, and the second Multi-electrode pulse arc welding control for controlling the arc length of the second welding wire during the application period of the second base voltage by controlling the base voltage of the second base voltage to be equal to a predetermined base voltage setting value Method. A first welding wire and a second welding wire, which are electrically insulated from each other from one welding torch, are fed at a preset feeding speed, respectively, and a first preset wire is supplied to the first welding wire. Repeating energization with one cycle of energization of the peak current and energization of the first base current set in advance, and the second peak current by applying the preset second peak voltage to the second welding wire And energizing the second base current by applying the second base voltage are repeated one cycle, and 2 between the first welding wire and the second welding wire and the work piece. In the multi-electrode pulse arc welding control method for generating and welding two arcs, a period from the start of the energization period of the first peak current to the elapse of a preset delay time is applied to the second welding wire. The second base voltage is applied to apply the second base current, and the second peak voltage is applied during the period from the elapsed time to the end of the first peak current application period. Energizing the second peak current, applying a second base voltage to energize the second base current during an energization period of the first base current, and determining a first peak voltage time in advance, Controlling the arc length of the first welding wire by changing the pulse frequency of the first wire welding current so that the average value of the first welding voltage is equal to the predetermined first voltage setting value;
The arc length of the second welding wire is controlled during the application period of the second peak voltage by controlling the second peak voltage to be equal to a predetermined peak voltage setting value, and the second Multi-electrode pulse arc welding control for controlling the arc length of the second welding wire during the application period of the second base voltage by controlling the base voltage of the second base voltage to be equal to a predetermined base voltage setting value Method. A first welding wire and a second welding wire, which are electrically insulated from each other from one welding torch, are fed at a preset feeding speed, respectively, and a first preset wire is supplied to the first welding wire. Repeating energization with one cycle of energization of the peak current and energization of the first base current set in advance, and the second peak current by applying the preset second peak voltage to the second welding wire And energizing the second base current by applying the second base voltage are repeated one cycle, and 2 between the first welding wire and the second welding wire and the work piece. In the multi-electrode pulse arc welding control method in which two arcs are generated and welded, an elapse time of a preset delay time from the start time of the first energization period of the first peak current is applied to the second welding wire. Until During the period of time, the second base voltage set in advance is applied to apply the second base current, and the period from the elapsed time point to the end point of the energization period of the first peak current is the second time period. A second peak current is applied to apply the second peak current, and the second base voltage is applied to supply the second base current during an energization period of the first base current. In the first energization period of the first peak current and the energization period of the first base current, the second base current is applied by applying the second base voltage, and an integer of 2 or more set in advance The same energization as the second time is repeated up to the nth time with the magnification n, and the first time to the nth current energization is repeated as one set,
The first peak voltage time is determined in advance, and the pulse frequency of the first wire welding current is changed so that the average value of the first welding voltage becomes equal to the predetermined first voltage setting value. Control the arc length of 1 welding wire,
The arc length of the second welding wire is controlled during the application period of the second peak voltage by controlling the second peak voltage to be equal to a predetermined peak voltage setting value, and the second Multi-electrode pulse arc welding control for controlling the arc length of the second welding wire during the application period of the second base voltage by controlling the base voltage of the second base voltage to be equal to a predetermined base voltage setting value Method. A first welding wire and a second welding wire, which are electrically insulated from each other from one welding torch, are fed at a preset feeding speed, respectively, and a first preset wire is supplied to the first welding wire. Repeating energization with one cycle of energization of the peak current and energization of the first base current set in advance, and the second peak current by applying the preset second peak voltage to the second welding wire And energizing the second base current by applying the second base voltage are repeated one cycle, and 2 between the first welding wire and the second welding wire and the work piece. In multi-electrode pulse arc welding equipment that generates and welds two arcs,
A voltage detection circuit for detecting a first welding voltage between the first welding wire and the workpiece and outputting a voltage detection signal; a voltage setting circuit for outputting a voltage setting signal; the voltage detection signal; A modulation circuit that receives the voltage setting signal as an input and outputs a first pulse period signal by pulse frequency modulation control based on an error between the signals; a first peak current setting circuit that outputs a first peak current setting signal; The first base current setting circuit for outputting the first base current setting signal, the first pulse period signal, the first peak current setting signal, and the first base current setting signal as inputs. And a first switching circuit that switches between the first peak current setting signal and the first base current setting signal in accordance with a first pulse period signal and outputs the first current control setting signal. , A first welding power supply device that controls the first wire welding current by the first current control setting signal, a magnification setting circuit that outputs a magnification setting signal n that is an integer of 2 or more, and the first pulse period A period conversion circuit that receives a signal as an input and is synchronized with the signal and converts the signal into a signal having a period of the magnification setting signal n times, and outputs a second pulse period signal, and a delay that outputs a delay time setting signal A low level period determined by the delay time setting signal from the time when the second pulse period signal changes from a low level to a high level by inputting the time setting circuit, the second pulse period signal, and the delay time setting signal. A delay circuit that outputs a delay signal, and a logical product circuit that ANDs the second pulse period signal and the delay signal and outputs a switching signal A peak voltage setting circuit that outputs a peak voltage setting signal, a base voltage setting circuit that outputs a base voltage setting signal, the switching signal, the peak voltage setting signal, and the base voltage setting signal as inputs, and the switching signal A second switching circuit for switching a peak voltage setting signal and the base voltage setting signal to output as a voltage control setting signal; and detecting a second welding voltage between the second welding wire and the workpiece 2 A second voltage detection circuit that outputs a second voltage detection signal, and a voltage error amplification circuit that outputs the voltage error amplification signal with the second voltage detection signal and the voltage control setting signal as inputs. A multi-electrode pulse arc welding apparatus composed of a second welding power source device for controlling a second welding voltage by the voltage error amplification signal.

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