JP2004017059A - Arc start control method of laser irradiation electric arc welding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve such problems that a tip of a welding wire is melted by irradiation with laser beams, deposition is generated when the welding wire by the advance feeding is brought into contact with a base metal to achieve defective arc start in an arc start control method in which the advance feeding of the welding wire to the base metal is started when a welding start signal St is input, and the output of a welding power source device 6 is started in a laser beam irradiation arc welding to perform the welding by emitting laser beams on a molten pool of arc welding, the withdrawal feeding of the welding wire from the base metal is started and a small initial current runs when the welding wire is brought into contact with the base metal by this advance feeding, the advance feeding of the welding wire is re-started after the welding wire is separated from the base metal by this withdrawal feeding and the initial arc is generated, and a regular welding current runs to transfer to a stationary arc generating condition. <P>SOLUTION: In this arc start control method of a laser beam irradiation arc welding, the laser beam emission is started at or after generation of the initial arc. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
BACKGROUND OF THE INVENTION
TECHNICAL FIELD The present invention relates to an arc start control method for laser irradiation arc welding in which consumable electrode arc welding is performed while irradiating a laser, and in particular, a retract arc for starting an arc by advancing / retreating / re-forwarding a welding wire at the start of the arc. It relates to the synchronization between start and start of laser irradiation.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a laser irradiation arc welding method has been performed in which welding is performed by irradiating a YAG laser, a semiconductor laser, or the like on a molten pool of consumable electrode arc welding or its peripheral portion. According to this welding method, it is possible to improve the arc start property by irradiating a laser prior to the start of feeding of the welding wire, and further, an increase in heat input to the base material due to laser irradiation and laser irradiation. The stabilization of the arc generation state by means of this makes it possible to perform high-speed welding about 2 to 3 times that of arc welding alone. Hereinafter, an arc start control method in this laser irradiation arc welding will be described with reference to the drawings.
[0003]
[Prior art 1]
FIG. 6 is a configuration diagram of a laser irradiation arc welding apparatus. The welding power source device 6 outputs a welding voltage Vw and a welding current Iw suitable for welding, and controls feeding of the welding wire 1 although not shown. The welding wire 1 is fed to the base material 2 through the welding torch 4 at a predetermined feeding speed Fw by the rotation of the feeding roll 5 of the wire feeding device, and attached to the tip of the welding torch 4. Power is supplied from the power supply tip, and an arc 3 is generated between the base metal 2 and a molten pool 2a is formed. The laser oscillation device 9 is an oscillation device such as a YAG laser or a semiconductor laser, and outputs a laser 7 having an output value Pw. The laser irradiation head 8 irradiates the molten pool 2a or its peripheral part with the laser 7. When a welding start signal St is input from an external welding robot control device or the like, the preceding irradiation time timer circuit TTP outputs an output start signal On that is on-delayed for a predetermined preceding irradiation time Tp from that point. . Accordingly, when the welding start signal St is input to the laser oscillation device 9, the irradiation of the laser 7 is started, and then the output start signal On is output after the preceding irradiation time Tp has elapsed. Output of the welding power source 6 is started, and feeding of the welding wire 1 is also started.
[0004]
FIG. 7 is a timing chart of each signal in the above welding apparatus. FIG. 4A shows the time change of the welding start signal St, FIG. 4B shows the time change of the output start signal On, FIG. 4C shows the time change of the laser output value Pw, and FIG. FIG. (D) shows the time change of the feeding speed Fw, FIG. (E) shows the time change of the welding voltage Vw, FIG. (F) shows the time change of the welding current Iw, and FIG. -(G3) show the state of the arc generating part at each time. Hereinafter, a description will be given with reference to FIG.
[0005]
(1) Period from time t1 to t2 (preceding irradiation time Tp)
When the welding start signal St is input (High level) as shown in FIG. 9A at time t1, laser irradiation starts as shown in FIG. However, as shown in FIG. 4B, since the output start signal On is not output during this period (Low level), feeding of the welding wire is started as shown in FIG. In addition, as shown in FIG. 5E, the welding voltage Vw is not output. The state of the arc generating part immediately after time t1 is as shown in (G1) of the figure. The welding wire 1 fed through the feeding tip 4a is in a stopped state, and the base material 2 is irradiated with the laser 7. A plume 7a (high temperature plasma) is formed in the irradiated portion. During this period, no arc is generated between the welding wire 1 and the base material 2.
[0006]
(2) Period from time t2 to t3
When the preceding irradiation time Tp elapses at time t2, the output start signal On is output (High level) as shown in FIG. In response to this, as shown in FIG. 4D, feeding of the welding wire is started, and the feeding speed Fw is a speed corresponding to a slow initial feeding speed set value Fsi of about several m / min. Become. At the same time, as shown in FIG. 5E, the output of the welding voltage Vw is started, and during this period, no arc is generated between the welding wire and the base material, so that value Is the maximum no-load voltage Vnl. Further, as shown in FIG. 5F, the welding current Iw is not energized because it is in a no-load state. The state of the arc generating portion during this period is as shown in FIG. 2G2 where the welding wire 1 is fed in the direction of the arrow and the tip portion gradually approaches the base material 2. On the other hand, the space occupied by the plume 7a is gradually expanded by preceding irradiation of the laser 7, and the tip of the welding wire and the plume 7a are very close to each other immediately before time t2.
[0007]
(3) Period after time t3
As shown in the figure (G3), a welding voltage Vw is applied to the welding wire 1 and a plume 7a of high-temperature plasma is formed in the space between the welding wire tip and the base material. The arc 3 is in a state that is very easy to fire. When the arc 3 is ignited at time t3, the welding voltage Vw changes to an arc voltage value corresponding to a voltage setting value Vs equal to or lower than a predetermined first reference voltage value Vt1, as shown in FIG. . In response to this change, as shown in FIG. 4D, the feeding speed Fw becomes a speed corresponding to the steady feeding speed set value Fs, and as shown in FIG. A steady welding current Ic is obtained.
[0008]
As described above, in the arc start control method of laser irradiation arc welding, a favorable arc start is performed by forming a plume in the space between the tip of the welding wire and the base material by preceding irradiation with a laser. However, this method has the following drawbacks. That is, (1) since the welding torch normally stops without moving during the preceding irradiation of the laser, the heat input to the base metal becomes large, so that it melts down when the base material is a thin plate. May occur. (2) If the laser irradiation position on the base metal and the welding wire feeding timing are slightly shifted, the formation state of the plume changes, and the arc start becomes worse. Conventional method 2 described below has been proposed as a method for solving these problems and realizing high-speed welding by laser irradiation.
[0009]
[Prior Art 2]
The configuration of the welding apparatus of prior art 2 is such that the preceding irradiation time timer circuit TTC in FIG. 1 described above is removed and a welding start signal St is simultaneously input to the laser oscillation device 9 and the welding power source device 6. Prior art 2 performs a retract arc start method in laser irradiation arc welding. The retract arc start method is a method in which an arc start is performed by causing the welding wire to forward feed / reverse feed / re-forward feed at the time of arc start.
[0010]
FIG. 8 is a timing chart of each signal when the retract arc start method is performed in the above welding apparatus. FIG. 4A shows the time change of the welding start signal St, FIG. 2B shows the time change of the laser output value Pw, and FIG. 3C shows the time change of the feed speed Fw. Fig. (D) shows the time change of the welding voltage Vw, Fig. (E) shows the time change of the welding current Iw, and Fig. (F) shows the time change of the wire tip-base metal distance or arc length Lw. (G1)-(G5) show the state of the arc generating part at each time. Hereinafter, a description will be given with reference to FIG.
[0011]
(1) Period from time t1 to t2 (forward feed)
When the welding start signal St is input (High level) as shown in FIG. 9A at time t1, laser irradiation is started as shown in FIG. At the same time, as shown in FIG. 6C, feeding of the welding wire is started, and the feeding speed Fw becomes a speed corresponding to the initial feeding speed set value Fsi. As shown in FIG. The voltage Vw becomes the no-load voltage Vnl and, as shown in FIG. 5E, the welding current Iw is in the no-load state and is not energized. Further, as shown in FIG. 5F, the wire tip / base material distance Lw gradually decreases. The state of the arc generating part at time t1 is shown in FIG.
[0012]
(2) Period from time t2 to t3 (reverse feed)
As shown in (G2), when the welding wire 1 contacts the base material 2 at time t2 by the above-described forward feeding, the welding voltage Vw is set to a predetermined second value as shown in (D). It changes to a short circuit voltage value of about several volts below the reference voltage value Vt2. In response to this change, as shown in FIG. 5C, the backward feeding of the welding wire from the base material is started, and the feeding speed Fw becomes a speed corresponding to the backward feeding speed set value Fsr. . Here, when the feeding speed Fw is a negative value, it indicates that the feeding is backward. Further, as shown in FIG. 5E, the welding current Iw is an initial current Is having a predetermined small current value. Since the welding wire starts to be fed backward from the time t2, the time required for the rotation direction of the wire feeding motor to be reversed and the time for the backward feeding of the play of the welding wire in the welding torch is required. During this period of t3, the welding wire remains in contact with the base metal as shown in FIG.
[0013]
(3) Period from time t3 to t4 (reverse feed)
As shown in FIG. 4G3, when the welding wire 1 is separated from the base material 2 by the above-described backward feeding at time t3, an initial arc 3a is generated. When the initial arc 3a is generated, the welding voltage Vw changes to an arc voltage value that exceeds the second reference voltage value Vt2 as shown in FIG. During this period from the time of this change until a predetermined delay time Td elapses, the feed speed Fw maintains the reverse feed speed, as shown in FIG. Thus, the welding current Iw maintains the initial current Is described above. Further, as shown in FIG. 5F, the arc length Lw is gradually increased by the backward feeding while the initial arc 3a is generated.
[0014]
(4) Period after time t4 (re-forward feed)
When the delay time Td elapses at time t4, the welding wire is fed forward again as shown in FIG. 5C, and the feeding speed Fw is a speed corresponding to the steady feeding speed set value Fs. Become. At the same time, the welding voltage Vw becomes an arc voltage value corresponding to the voltage set value Vs as shown in FIG. 4D, and the welding current Iw becomes a steady welding current Ic as shown in FIG. Further, as shown in FIG. 5F, the arc length Lw converges to the steady arc length Lc at time t5 when the convergence time Tc has elapsed from time t4. As shown in FIG. 4G4, the state of the arc generating portion shifts to the steady arc 3 in which the steady welding current Ic is energized at time t4, and then at time t5 as shown in FIG. 5G5. The arc length is an appropriate value.
[0015]
As described above, in the retract arc start method, the arc start is improved regardless of the effect of laser irradiation by feeding the welding wire forward / backward / re-forwarding. Laser irradiation is necessary to increase the amount of heat input during welding and to stabilize the arc generation state to enable high-speed welding.
[0016]
[Problems to be solved by the invention]
FIG. 9 is a timing chart corresponding to FIG. 8 for explaining the problem of the related art 2. The signals in FIGS. 9A to 9G are the same as those in FIG. Hereinafter, a description will be given with reference to FIG.
[0017]
(1) Period from time t1 to t2
Since the operations of the signals in FIGS. 9A to 9F during this period are the same as those in FIG. 8, description thereof is omitted. However, as shown in FIG. 5G1, since a part of the laser is also applied to the tip of the welding wire, the tip of the welding wire melts to form a droplet 1a. Since the laser is irradiated through a narrow space between the welding wire and the base material, it is usual that a part of the laser is irradiated onto the welding wire. Therefore, the welding wire tip often melts during this period.
[0018]
(2) Period after time t2
As shown in FIG. 4G2, when the welding wire comes into contact with the base material 2 by forward feeding at time t2, the welding voltage Vw is equal to or lower than the second reference voltage value Vt2 as shown in FIG. Changes to short circuit voltage value. In response to this change, as shown in FIG. 5C, the welding wire starts to be fed backward, and the feeding speed Fw becomes a speed corresponding to the backward feeding speed set value Fsr. At the same time, the welding current Iw becomes the initial current Is as shown in FIG. As shown in FIG. (G2), when the droplet 1a at the tip of the welding wire comes into contact with the base material, as shown in FIG. (G3), the droplet 1a in the back side portion not irradiated with the laser is cooled. To form a weld 1b with the base material. When welding 1b occurs, as shown in FIG. 3C, even if the welding wire is fed backward, the welding wire is not separated from the base material, so that no initial arc is generated. Therefore, the welding voltage Vw remains at the short-circuit voltage value as shown in FIG. 4D, and the welding current Iw remains at the initial current Is as shown in FIG. Therefore, the arc does not occur indefinitely and the arc start fails.
[0019]
The above is the case of welding, but even if welding does not occur, when the droplet 1a at the tip of the welding wire comes into contact with the base material at time t2, large spatter is scattered and adheres to the base material, and the bead appearance May also worsen.
[0020]
Accordingly, the present invention provides an arc start control method for laser irradiation arc welding that solves the above-described problems and is excellent in arc start performance and capable of high-speed welding.
[0021]
[Means for Solving the Problems]
The invention of claim 1 is a laser irradiation arc welding in which welding is performed by irradiating a weld pool or its peripheral portion of consumable electrode arc welding with welding, and when a welding start signal is input to the welding power source device, Starts forward feeding to the base metal and starts output of the welding power source. When the welding wire comes into contact with the base metal by this forward feed, it starts reverse feeding from the base metal of the welding wire and reduces the current. The initial arc is generated when the welding wire is separated from the base metal by this backward feeding and the initial arc is generated, and then the welding wire is re-forwarded and the steady welding current is applied. In an arc start control method for shifting from a state to a steady arc generation state,
An arc start control method for laser irradiation arc welding, characterized in that the laser irradiation is started at or after the occurrence of the initial arc.
[0022]
The invention according to claim 2 is the arc start control method of laser irradiation arc welding according to claim 1, wherein the laser irradiation is started from the start of re-forward feeding or after.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[Embodiment 1]
Embodiment 1 of the present invention is an arc start control method of laser irradiation arc welding in which, in the above-described retract arc starting method, laser irradiation is started from the time when the initial arc is generated or after. According to this method, since the laser is not irradiated during the period until the welding wire comes into contact with the base material by forward feeding, the welding wire tip does not melt and no droplets are formed. Spatter adhesion does not occur. The first embodiment will be described below with reference to the drawings.
[0024]
FIG. 1 is a configuration diagram of a laser irradiation arc welding apparatus according to Embodiment 1 of the present invention. In the figure, the same components as those in FIG. 6 described above are denoted by the same reference numerals, and description thereof is omitted. Differences from FIG. 6 are as follows. The welding start signal St is directly input to the welding power supply device 6, and a laser output start signal Pon is output from the welding power supply device 6. When this laser output start signal Pon is input (High level), the laser oscillation device 9 starts laser irradiation. When the welding start signal St is input (High level), the welding power source device 6 starts the forward feeding of the welding wire and the output of the welding voltage.
[0025]
FIG. 2 is a timing chart of each signal in FIG. (A) shows the time change of the welding start signal St, (B) shows the time change of the laser output start signal Pon, (C) shows the time change of the feeding speed Fw, Fig. (D) shows the time change of the welding voltage Vw, Fig. (E) shows the time change of the welding current Iw, and Fig. (F) shows the time change of the wire tip-base metal distance or arc length Lw. (G1)-(G5) show the state of the arc generating part at each time. In the figure, the description of the same operation as that of FIG. 8 is omitted, and only the operation different from that of FIG. 8 will be described.
[0026]
From time t3 when the initial arc 3a is generated as shown in (G3) and the welding voltage Vw exceeds the second reference voltage value Vt2 as shown in (D), (B) in FIG. As shown in FIG. 4, the laser output start signal Pon changes to the high level, and laser irradiation is started. Thus, by starting laser irradiation from the time when the initial arc 3a is generated, formation of droplets by laser irradiation can be prevented before time t2 when the welding wire comes into contact with the base material. For this reason, adhesion of the above-mentioned welding and spatter can be prevented. The arc start can be improved by the retract arc start method even without laser irradiation. In addition, since laser is irradiated during welding after a good arc start, high-speed welding is also possible.
[0027]
By the way, the reason why laser irradiation is not started from the period of time t2 to t3 after contact is that if the laser is irradiated at the time of contact, a part of the contact portion may melt and welding may occur thereafter. Further, the laser irradiation may be started not at the time when the initial arc is generated but at a time after that. However, it is necessary to start laser irradiation before time t5 when the steady arc becomes the steady arc length Lc. This is because the arc start portion of high-speed welding tends to become shallow, and it is necessary to bring this close to an appropriate value by laser irradiation. For this purpose, it is necessary to start the laser irradiation before and after the time when it converges to the steady arc length Lc.
[0028]
FIG. 3 is a block diagram of welding power supply apparatus 6 according to the first embodiment. Hereinafter, a description will be given with reference to FIG.
[0029]
The output control circuit INV receives a commercial power supply (3-phase 200V, etc.) as input, performs output control such as inverter control and thyristor control according to a drive signal Dv described later, and outputs a welding voltage Vw and a welding current Iw suitable for welding. . The voltage detection circuit VD detects the welding voltage Vw and outputs a voltage detection signal Vd. The short circuit determination circuit SD outputs a short circuit determination signal Sd that is at a high level when the voltage detection signal Vd is equal to or lower than the second reference voltage value Vt2 shown in FIG. The delay circuit TTD outputs a delay signal Ttd that is at a high level only for a predetermined delay time Td from the time point when the short circuit determination signal Sd changes from a high level to a low level (at the time of initial arc occurrence). The initial feed speed setting circuit FSI outputs a predetermined initial feed speed setting signal Fsi. The logic negation circuit NOT logically inverts the short circuit determination signal Sd and outputs a switching signal Not. The initial feeding switching circuit SI is connected to the a side until the switching signal Not changes from the High level to the Low level (short circuit), and the initial feeding speed setting signal Fsi is used as the feeding speed control setting signal Fsc. After the output is changed from the High level to the Low level, the mode is switched to the b side, and a backward feed switching circuit output signal Sr, which will be described later, is output as the feed speed control setting signal Fsc. The reverse feed speed setting circuit FSR outputs a predetermined reverse feed speed setting signal Fsr. The steady feeding speed setting circuit FS outputs a predetermined steady feeding speed setting signal Fs. The reverse feed switching circuit SR is connected to the a side until the delay signal Ttd changes from the High level to the Low level, and outputs the reverse feed speed setting signal Fsr as the reverse feed switching circuit output signal Sr. Then, after changing from the High level to the Low level, it switches to the b side and outputs the above-mentioned steady feeding speed setting signal Fs as the backward feeding switching circuit output signal Sr. The feed control circuit FC receives a feed control signal Fc for feeding the welding wire at a speed corresponding to the feed speed control setting signal Fsc when the welding start signal St input from the outside is at a high level. Output to the wire feed motor WM.
[0030]
The voltage setting circuit VS outputs a predetermined voltage setting signal Vs shown in FIG. The initial current setting circuit ISI outputs a predetermined initial current setting signal Isi shown in FIG. The voltage error amplification circuit EV amplifies an error between the voltage setting signal Vs and the voltage detection signal Vd and outputs a voltage error amplification signal Ev. By the feedback control by this voltage error amplifier circuit EV, the external characteristic of the welding power source device becomes a constant voltage characteristic for supplying a steady welding current. The current detection circuit ID detects the welding current Iw and outputs a current detection signal Id. The current error amplification circuit EI amplifies an error between the initial current setting signal Isi and the current detection signal Id and outputs a current error amplification signal Ei. By the feedback control by the current error amplifier circuit EI, the external characteristic of the welding power source device becomes a constant current characteristic or a drooping characteristic for supplying an initial current. The external characteristic switching circuit SP is connected to the a side until the delay signal Ttd changes from the High level to the Low level, and outputs the current error amplification signal Ei as the error amplification signal Ea, and from the High level to the Low level. Then, the voltage is switched to the b side, and the voltage error amplified signal Ev is output as the error amplified signal Ea. The drive circuit DV outputs a drive signal Dv for controlling the output control circuit INV according to the error amplification signal Ea when the welding start signal St is at a high level.
[0031]
The laser output start signal generation circuit PON, which is a circuit unique to the present invention, becomes a high level when the short-circuit determination signal Sd changes from the high level to the low level (at the time of initial arc occurrence), and thereafter the laser output that maintains that state. A start signal Pon is output. Further, when laser irradiation is started after the initial arc is generated, the laser output start signal generation circuit PON determines a predetermined time from the time when the short circuit determination signal Sd changes from the High level to the Low level. A laser output start signal Pon that becomes a high level after the lapse of time and holds the state thereafter may be output.
[0032]
[Embodiment 2]
Embodiment 2 of the present invention is an arc start control method for laser irradiation arc welding in which the laser irradiation is started from the start of re-forward feeding or after that in the above-described retract arc starting method. According to this method, since the laser is not irradiated during the period until the welding wire comes into contact with the base material by forward feeding, the tip of the welding wire is not melted to form a droplet, and welding is performed after the contact. In addition, no spatter adhesion occurs. Embodiment 2 of the present invention will be described below with reference to the drawings.
[0033]
The welding apparatus according to the second embodiment is the same as that shown in FIG. However, as will be described later, the output timing of the laser output start signal Pon is different from that of the first embodiment. FIG. 4 is a timing chart of each signal in the second embodiment corresponding to FIG. 2 described above. The signals in FIGS. 5A to 5G are the same as those in FIG. Hereinafter, only operations different from those in FIG. 2 will be described.
[0034]
From the point in time when the delay time Td has elapsed at time t4 and re-forward feeding is started as shown in FIG. 10C and the state moves to the steady arc 3 as shown in FIG. ), The laser output start signal Pon changes to a high level, and laser irradiation is started. Thus, by starting laser irradiation from the start of re-advance feeding, formation of droplets by laser irradiation can be prevented before time t2 when the welding wire and the base material come into contact with each other. For this reason, adhesion of the above-mentioned welding and spatter can be prevented. The laser irradiation may be started before and after the time when the steady arc shown at time t5 converges to the steady arc length from the start of re-forward feeding shown at time t4. The reason for this is the same as in the first embodiment. The reason for starting laser irradiation not from the initial arc occurrence time but from the start point of re-forward feeding as in the first embodiment is that the arc length is still short immediately after the initial arc occurrence. This is because, when the laser is irradiated, a large droplet is formed at the tip of the welding wire and the spatter may be scattered. By the way, the arc start property can be improved by the retract arc start method even without laser irradiation.
[0035]
The block diagram of the welding power source device 6 of the second embodiment is the same except that the laser output start signal generation circuit PON in FIG. 3 described above is changed as follows. The laser output start signal generation circuit PON according to the second embodiment changes to the high level when the delay signal Ttd changes from the high level to the low level (at the time of re-forward feeding start), and then outputs the laser output start signal Pon that holds the state thereafter. Output. In addition, when laser irradiation is started after the start of re-forward feeding, the laser output start signal generation circuit PON is operated after a predetermined time has elapsed since the delay signal Ttd changed from the High level to the Low level. The laser output start signal Pon that becomes the high level and holds the state thereafter may be output.
[0036]
[effect]
FIG. 5 is a comparison diagram of good arc start rates between the prior art and the present invention. This figure shows the case of MIG welding of an aluminum alloy that is difficult to perform a good arc start. This figure uses a 1.2 mm diameter aluminum alloy wire (JIS A5356 material) as a welding wire and an aluminum alloy material (JIS A5052 material) as a base material, and repeatedly starts arcs at a welding current of 100 A. The ratio of the good arc start in which there was no adhesion of welding and large-sized spatter was measured. As is clear from the figure, in the prior art 2, the good arc start rate was 47%. In contrast, in the present invention, the good arc start rate was greatly improved to 95%. Moreover, high-speed welding can be performed by laser irradiation after arc start.
[0037]
【The invention's effect】
According to the arc start control method of laser irradiation arc welding of the present invention, the laser beam is not irradiated until the welding wire is fed forward and comes into contact with the base material. No droplets are formed, and no welding or spatter deposition occurs after the contact. For this reason, it is possible to always obtain a good arc start property. At the same time, since the laser irradiation is started after the initial arc is generated or after the re-forward feeding is started, high-speed welding can be performed by optimizing the melting of the arc start portion without impairing the arc start performance.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a welding apparatus according to Embodiment 1 of the present invention.
2 is a timing chart in the welding apparatus of FIG. 1 according to Embodiment 1. FIG.
3 is a block diagram of a welding power source device 6 according to Embodiment 1. FIG.
FIG. 4 is a timing chart in the welding apparatus according to the second embodiment.
FIG. 5 is a comparative diagram of a good arc start rate showing the effect of the present invention.
6 is a configuration diagram of a welding apparatus according to Prior Art 1. FIG.
7 is a timing chart in the welding apparatus of FIG. 6 according to Prior Art 1. FIG.
FIG. 8 is a timing chart in the welding apparatus according to Prior Art 2.
FIG. 9 is a timing chart for explaining a problem of the conventional technique 2;
[Explanation of symbols]
1 Welding wire
1a droplet
1b welding
2 Base material
2a molten pool
3 arc / steady arc
3a initial arc
4 Welding torch
4a Feeding chip
5 Feeding roll
6 Welding power supply
7 Laser
7a plume
8 Laser irradiation head
9 Laser oscillator
DV drive circuit
Dv drive signal
Ea Error amplification signal
EI current error amplifier circuit
Ei Current error amplification signal
EV voltage error amplifier circuit
Ev Voltage error amplification signal
FC feed control circuit
Fc feed control signal
FS steady feed speed setting circuit
Fs Constant feed speed setting (value / signal)
Fsc Feeding speed control setting signal
FSI initial feed speed setting circuit
Fsi Initial feed speed setting (value / signal)
FSR reverse feed speed setting circuit
Fsr Reverse feed speed setting (value / signal)
Fw Feeding speed
Ic Steady welding current
ID current detection circuit
Id Current detection signal
INV output control circuit
ISI initial current setting circuit
Isi initial current setting signal
Iw welding current
Lc Steady arc length
Lw Distance between wire tip and base metal / arc length
NOT logic negation circuit
Not switching signal
On output start signal
PON laser output start signal generation circuit
Pon laser output start signal
Pw laser output value
SD short-circuit detection circuit
Sd Short circuit detection signal
SI initial feed switching circuit
SP external characteristic switching circuit
SR Reverse feed switching circuit
Sr Reverse feed switching circuit output signal
St welding start signal
Tc convergence time
Td delay time
Tp preceding irradiation time
TTD delay circuit
Ttd delay signal
TTP Pre-irradiation time timer circuit
VD voltage detection circuit
Vd Voltage detection signal
Vnl No-load voltage
VS voltage setting circuit
Vs Voltage setting (value / signal)
Vt1 first reference voltage value
Vt2 Second reference voltage value
Vw welding voltage

Claims (2)

In laser irradiation arc welding, in which welding is performed by irradiating laser to the weld pool or its peripheral part of consumable electrode arc welding, when a welding start signal is input to the welding power source, the welding wire is fed forward to the base material. When the welding wire comes into contact with the base metal by this forward feeding, the welding wire starts to be retracted from the base material and an initial current having a small current value is applied. After the welding wire is separated from the base metal by this backward feeding and the initial arc is generated, the welding wire is re-forwarded and the steady welding current is supplied to the steady arc generating state from the initial arc generating state. In the arc start control method to shift to
An arc start control method for laser irradiation arc welding, wherein the laser irradiation is started at or after the initial arc is generated. 2. The arc start control method of laser irradiation arc welding according to claim 1, wherein the laser irradiation is started from the start of re-forward feeding or after.

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