JP2014083553A - Pulsed arc welding control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the following problems in pulsed arc welding: melt down and an undercut are apt to occur when arc length is lengthened in order to prevent a short circuit caused when a droplet is separated; and the short circuit is apt to occur and the sputter increases when the arc length is shortened.SOLUTION: A pulsed arc welding control method is provided for repeatedly supplying a peak current and a base current in a pulses shape between a weld wire and a welding object. During a predetermined period up to second time in a base current period from first time in a peak current period, a feeding speed of the weld wire is lowered more than a feeding speed in rising time of the peak current, or the weld wire is inversely fed for feeding in the direction for separating from the welding object. Thereby, the arc length is shortened, and the short circuit is restrained when separating the droplet.

Description

  The present invention relates to a pulse arc welding control method for repeatedly supplying a peak current and a base current in a pulsed manner between a welding wire and a welding object.

  With regard to pulse arc welding, various techniques are used to stabilize the arc, prevent welding defects, and achieve a beautiful bead appearance.

  A method is known in which the feeding speed of the welding wire is changed in synchronization with the pulse current to induce the detachment of the droplets (see, for example, Patent Document 1). This method induces droplet detachment during peak current periods. However, during the peak current period, the arc reaction force is also strong, and it is difficult to detach, and the bead toes are uneven.

JP 60-180675 A

  In pulse arc welding, it is necessary to set a long arc length in order to prevent a short circuit when a droplet is detached. In this case, since the droplets transfer to the spray, a short circuit does not occur. However, increasing the arc length increases the welding voltage. Therefore, heat input to the base material increases, and the base material may be melted down. Further, since the arc spreads, a welding defect called undercut may occur.

  On the other hand, when the arc length is set short, there is a problem that a short circuit occurs when the droplets are detached and a large amount of spatter is generated.

  In the present invention, the pulse arc welding is considered to be classified into two periods, namely, a droplet detachment prediction period in which droplet detachment is expected to occur, and a wire preheating period that is a period other than the droplet detachment prediction period. In the preheating period, the welding voltage is set so that the arc length is as short as possible to prevent welding defects such as undercut. In the droplet detachment prediction period, the welding wire feeding speed is set to the feeding speed in the wire preheating period. It is another object of the present invention to provide a pulse arc welding control method that suppresses the occurrence of a short circuit and reduces the amount of spatter as much as possible by controlling the feed back in the direction of lowering or pulling up the welding wire.

  In order to solve the above problems, a pulse arc welding control method of the present invention is a pulse arc welding control method for repeatedly supplying a peak current and a base current in a pulsed manner between a welding wire and a welding object, During a predetermined period from the first time point during the peak current period to the second time point during the base current period, the feeding speed of the welding wire is set lower than the feeding speed at the rising edge of the peak current. Alternatively, the welding wire is fed backward in a direction in which the welding wire is pulled away from the welding object.

  In addition to the above, the pulse arc welding control method of the present invention is configured such that the first time point is a time point when the first predetermined time has elapsed from the rising time point of the peak current.

  In addition to the above, the pulse arc welding control method of the present invention is such that the first predetermined time is different for each pulse period or the same for each pulse period.

  In addition to the above, in the pulse arc welding control method of the present invention, the second time point is set to a time point when a second predetermined time has elapsed from the falling time point of the peak current.

  In addition to the above, the pulse arc welding control method of the present invention, when detecting the detachment of the droplet, returns the feeding speed to the feeding speed before the change without waiting for the elapse of the second predetermined time. It is.

  Further, in addition to the above, the pulse arc welding control method of the present invention further reduces the feeding speed of the welding wire when detecting a short circuit between the welding wire and the welding object during the second predetermined time, or The reverse feed amount of the welding wire is further increased.

  In addition to the above, the pulse arc welding control method of the present invention is such that the predetermined period is shorter than the peak current period.

  Further, in addition to the above, the pulse arc welding control method of the present invention provides a welding wire and an object to be welded when the welding wire is fed at the same feeding speed as the feeding speed at the rise of the peak current. When a short circuit is detected, the feeding speed of the welding wire is made lower than the feeding speed at the time of rising of the peak current, or the reverse feeding is performed in which the welding wire is fed away from the welding object. It is what.

  According to the present invention, by controlling the wire feed speed in addition to the output waveform control of pulse arc welding, the arc length can be kept as short as possible, welding defects such as undercuts are hardly generated, and spatter is generated. The amount can be reduced, and a good bead appearance can be obtained.

The figure which shows schematic structure of the pulse arc welding machine in Embodiment 1 of this invention. Time chart of welding current and wire feed speed in Embodiment 1 of the present invention Time chart of welding current and wire feed speed in embodiment 2 of the present invention The figure which shows the relationship between the base current period and 1st predetermined time in Embodiment 2 of this invention. Time chart of welding current and wire feed speed in Embodiment 3 of the present invention The figure which shows schematic structure of the pulse arc welder in Embodiment 4 of this invention. Time chart of welding current, droplet detachment detection signal, and wire feed speed in Embodiment 4 of the present invention The figure which shows schematic structure of the pulse arc welder in Embodiment 5 of this invention. Time chart of welding current, short circuit detection signal, and wire feed speed in embodiment 5 of the present invention The figure which shows schematic structure of the pulse arc welder in Embodiment 6 of this invention. Time chart of welding current, short circuit detection signal, and wire feed speed in Embodiment 6 of the present invention

(Embodiment 1)
This Embodiment 1 is demonstrated using FIG. 1 and FIG. FIG. 1 is a diagram showing a schematic configuration of a consumable electrode type DC pulse arc welder according to the first embodiment. FIG. 2 is a time chart of the pulse welding current and wire feed speed in the first embodiment.

  The pulse arc welding machine shown in FIG. 1 performs full-wave rectification on the AC power input from the three-phase AC input 1 by the primary side rectifier 2, smoothes it by the smoothing capacitor 3, and converts it to DC power. DC power is converted into AC power by inverter control by the switching unit 4, and the voltage is stepped down to a welding voltage suitable for arc welding via a welding transformer 5. The output of the welding transformer 5 is full-wave rectified by the secondary side rectifier 6 and the reactor 7, and is supplied to the welding wire 9 serving as a consumable electrode of the anode via the welding tip 8. The welding wire 9 is fed by a wire feed motor 11, supplied with power from the welding tip 8, and generates an arc 26 between the base material 10 as a welding object and performs arc welding.

  The welding tip 8 is provided in a welding torch (not shown). The welding torch is attached to, for example, a manipulator of an industrial robot (not shown) and moved along the welding line.

  In arc welding, control is performed to keep the arc length constant. The arc voltage fed back by the voltage detector 12 and the set voltage preset by the voltage setting unit 13 are compared by the pulse current pulse time setting unit 14. The current value detected by the current detector 15 is also fed back to the pulse current pulse time setting unit 14. The pulse current pulse time setting unit 14 resets the necessary pulse current and pulse time based on the input information, etc., drives the switching unit 4 via the inverter drive circuit 16 to perform inverter control, and is necessary A good welding power.

  The wire feed motor 11 is driven via a wire feed motor drive circuit 17. Basically, the wire feed speed is the wire feed speed WF1 set by the wire feed speed WF1 setting unit 18. The welding wire 9 is fed toward the base material 10 to perform arc welding. Although details will be described later, the wire feed speed WF2 setting unit 21 is set with a wire feed speed WF2 that is slower than the wire feed speed WF1.

  A pulse arc welding control method using the pulse arc welder configured as described above will be described. In the pulse arc welding of the first embodiment, two periods are defined: a droplet detachment prediction period in which droplet detachment is considered to occur, and a wire preheating period that is a period other than the droplet detachment prediction period. explain. In the first embodiment, the feeding control of the welding wire 9 is performed in the two periods.

  In the wire preheating period, the wire feed speed is set on the wire feed speed WF1 setting section 18 side, and the pulse current pulse time setting section 14 is fed while feeding the welding wire 9 at the wire feed speed WF1. The output of the peak current Ip set in is started. The switching control unit 27 receives the rising of the peak current Ip set by the pulse current pulse time setting unit 14, and when the first predetermined time t1 set by the first predetermined time setting unit 19 has elapsed, the wire feeding The speed switching unit 20 is switched to the wire feed speed WF2 setting unit 21 side. The switching control unit 27 has a time counting function, a determination function for determining whether or not a predetermined time has elapsed, and the like. The wire feed speed WF2 set in the wire feed speed WF2 setting unit 21 is set to a value (slower value) lower than the wire feed speed WF1, or the welding wire 9 is moved from the base material 10. A reverse wire feed speed for feeding in the direction of separation is set.

  After the pulse current pulse time setting unit 14 starts outputting the peak current Ip, when the peak current period Tp elapses, the base current Ib is passed. The switching control unit 27 receives the falling of the peak current Ip from the pulse current pulse time setting unit 14, and after the second predetermined time t2 set in the second predetermined time setting unit 22 has elapsed, the wire feeding The speed switching unit 20 is switched to the wire feed speed WF1 setting unit 18 side. That is, switching to the higher wire feed speed side during the wire preheating period.

  In the pulse arc welding of the first embodiment, the timing (period) at which the droplets are detached is predicted in advance, and the peak current Ip is increased from the time tA when the first predetermined time t1 has elapsed from the rise of the peak current Ip. During the predetermined period t3 from the falling to the time tB when the second predetermined time t2 has elapsed, the wire feeding speed is reduced or the wire feeding speed is reversely fed, and the droplets are released in this state. Reduce the amount of spatter generated. The predetermined period t3 is a droplet detachment prediction period, and the period other than the predetermined period t3 is a wire preheating period.

  As described above, in the arc welding control method of the first embodiment, the wire feed speed WF is set to the wire feed rate at the rising edge of the peak current during the predetermined period t3 in which the droplets are predicted to be detached. The wire feed speed WF2 is lower than the wire feed speed WF1, which is the speed, or the wire feed speed WF2 is the reverse feed that feeds the welding wire 9 away from the base material. By doing so, when the droplet is about to leave, the distance between the welding wire 9 and the base material 10 is kept long, and the contact between the droplet and the base material 10 is prevented. It is possible to suppress spatter generated by contact between the droplet and the base material 10 before the separation.

  Note that the predetermined period t3 is a period from the first time point (time point tA) in the peak current period Tp to the second time point (tB) in the base current period. The first time point is a time point when the first predetermined time t1 has elapsed from the rising time point of the peak current Ip. The second time point is a time point when the second predetermined time t2 has elapsed from the falling time point of the peak current Ip.

  It should be noted that the predetermined period t3, the first predetermined time t1, the second predetermined time t2, and the like that the droplets are expected to detach are obtained in advance through experiments or the like, for example.

  In the first embodiment, an example in which the predetermined period t3, the first predetermined time t1, and the second predetermined time t2 are constant values is shown.

(Embodiment 2)
The second embodiment will be described with reference to FIG. 1, FIG. 3, and FIG. In the second embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. FIG. 1 is a diagram showing a schematic configuration of a consumable electrode type DC pulse arc welder according to the second embodiment. FIG. 3 is a time chart of pulse welding current and wire feed speed in the second embodiment. FIG. 4 is a diagram showing the relationship between the base current period and the first predetermined time in the second embodiment. The main difference from the first embodiment is that the first predetermined time is changed according to the base current period.

  As shown in FIG. 3, in the pulse arc welding control, the base current period Tb through which the base current Ib flows may change due to the constant arc length control. When the base current period Tb in which the base current Ib flows is the base current period Tb1, the switching control unit 27 receives the rising of the peak current Ip, and the first predetermined time t1 set by the first predetermined time setting unit 19 is After the elapse, the wire feeding speed switching unit 20 is switched to the wire feeding speed WF2 setting unit 21 side, and the wire feeding speed is reduced from the wire feeding speed WF1 to the wire feeding speed WF2.

  However, as shown in FIG. 3, when the base current period Tb2, which is the base current period subsequent to the base current period Tb1, becomes longer than the base current period Tb1, it is set by the first predetermined time setting unit 19. The first predetermined time t4 from the rise of the peak current Ip to the reduction of the wire feed speed to WF2 is the first predetermined time t1 from the previous rise of the peak current Ip to the reduction of the wire feed speed to WF2. Set it shorter. This is because the preheating of the welding wire 9 in the base current period Tb2 in which the base current Ib flows is increased, so that it is assumed that the timing at which the droplets are released becomes earlier. The first predetermined time t4 is calculated by the first predetermined time setting unit 19 based on the base current period.

  Conversely, although not shown, when the base current period Tb3, which is the base current period next to the base current period Tb1, becomes shorter than the base current period Tb1, it is set by the first predetermined time setting unit 19. The first predetermined time is set longer than the first predetermined time t1 until the wire feed speed is reduced to WF2 from the previous rise of the peak current Ip. This is because the preheating of the welding wire 9 in the base current period Tb3 in which the base current Ib flows is reduced, so that it is assumed that the timing at which the droplets are detached is delayed. The first predetermined time is calculated by the first predetermined time setting unit 19 based on the base current period, as described above.

  As described above, in the second embodiment, the first predetermined time set by the first predetermined time setting unit 19 can be changed and set based on the previous base current period Tb. Specifically, as shown in FIG. 4, the relationship between the base current period Tb and the first predetermined time is stored in the first predetermined time setting unit 19, and in the first predetermined time setting unit 19, The first predetermined time is determined based on the base current period Tb. Thus, the arc length can be controlled to be short by controlling the first predetermined time.

(Embodiment 3)
The third embodiment will be described with reference to FIGS. 1 and 5. In the third embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. FIG. 1 is a diagram showing a schematic configuration of a consumable electrode type DC pulse arc welding machine according to the third embodiment. FIG. 5 is a time chart of pulse welding current and wire feed speed in the third embodiment.

  The main difference from the first embodiment is that the predetermined period t3, which is a droplet detachment prediction period, is shorter than that described in the first embodiment.

  The droplet detachment reduces the arc force including the base current period Tb after the welding current is reduced from the peak current Ip to the base current Ib, or the transition period in which the welding current is reduced from the peak current Ip to the base current Ib. This occurs mainly when the arc reaction force on the droplets is reduced. Therefore, as shown in FIG. 5, the wire feed speed switching unit 20 is connected to the wire feed speed WF2 only during the period Td from immediately before the peak of the peak current Ip to just after the peak of the peak current Ip. Switch to the setting unit 21 side. By doing in this way, effects, such as sputter suppression, can be acquired in the minimum required droplet detachment prediction period. If the droplet detachment prediction period is short, the feeding speed can be increased. In the third embodiment, the period Td of the wire feed speed WF2 is controlled to be shorter than the peak current period Tp.

  The above-mentioned immediately before the fall of the peak current Ip is, for example, a time point between 85% and 95% of the peak current period Tp when the start of the peak current is used as a reference. Further, the above-mentioned immediately after the fall of the peak current Ip is, for example, a time point between 5% and 15% of the base current period when the start of the base current is used as a reference.

(Embodiment 4)
This Embodiment 4 is demonstrated using FIG. 6 and FIG. In the fourth embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. FIG. 6 is a diagram showing a schematic configuration of a consumable electrode type DC pulse arc welder according to the fourth embodiment. FIG. 7 is a time chart of the pulse welding current and the wire feed speed in the fourth embodiment. The main difference from the first embodiment is that a droplet detachment detection unit 23 is provided, and the wire feed speed is switched based on detection of droplet detachment.

  During the wire preheating period, the wire feeding speed is set on the wire feeding speed WF1 setting unit 18 side, and the pulse current pulse time setting unit 14 peaks while feeding the welding wire 9 at the wire feeding speed WF1. The output of the current Ip is started. The switching control unit 27 receives the rising of the peak current Ip set by the pulse current pulse time setting unit 14, and when the first predetermined time t1 set by the first predetermined time setting unit 19 has elapsed, the wire feeding The speed switching unit 20 is switched to the wire feed speed WF2 setting unit 21 side and waits for the detachment of the droplets. Thereafter, after the peak current Ip is continuously output by the pulse current pulse time setting unit 14, when the peak current period Tp elapses, the pulse current pulse time setting unit 14 shifts to the base current Ib, and the droplets are detached due to the reduced arc reaction force.

  Here, in the above-described first embodiment, the output of the base current Ib is continued by the pulse current pulse time setting unit 14 even after the droplets are detached, and the second predetermined time t2 is set from the falling point of the peak current Ip. When the time has elapsed, the wire feed speed is switched from the wire feed speed WF2 to the wire feed speed WF1. That is, it switches to the high wire feed speed side at the time of steady welding.

  However, in the fourth embodiment, when the switching control unit 27 receives the droplet detachment signal Rd (ON) indicating that the droplet has separated from the droplet detachment detecting unit 23, the second predetermined time t2. Without waiting for the elapse of time, the wire feeding speed switching unit 20 is switched to the wire feeding speed WF1 setting unit 18 side, that is, the high wire feeding speed side which is the wire feeding speed in the wire preheating period. Thereby, the fall period of wire feeding speed can be suppressed to the minimum.

(Embodiment 5)
The fifth embodiment will be described with reference to FIG. 8 and FIG. In the fifth embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. FIG. 8 is a diagram showing a schematic configuration of a consumable electrode type direct-current pulse arc welder according to the fifth embodiment. FIG. 9 is a time chart of the pulse welding current and wire feed speed in the fifth embodiment. The main difference from the first embodiment is that a short-circuit detection unit 24 and a wire feed speed WF3 setting unit 25 are provided, and the wire feed speed is switched based on detection of a short circuit.

  During the wire preheating period, the wire feeding speed is set on the wire feeding speed WF1 setting unit 18 side by the switching control unit 27. The pulse current pulse time setting unit 14 starts outputting the peak current Ip while feeding the welding wire 9 at the wire feed speed WF1. The switching control unit 27 receives the rising edge of the peak current Ip set by the pulse current pulse time setting unit 14, and after the first predetermined time t1 set by the first predetermined time setting unit 19 has elapsed, the wire feeding The speed switching unit 20 is switched to the wire feed speed WF2 setting unit 21 side. The wire feed speed WF2 is set to a value lower than the wire feed speed WF1. Alternatively, the wire feeding speed WF2 is set to the wire feeding speed for reverse feeding.

  After that, the pulse current pulse time setting unit 14 continues to output the peak current Ip. When the peak current period Tp elapses, the pulse current pulse time setting unit 14 shifts to the base current period Tb in which the base current Ib is output, thereby reducing the arc reaction force. Drops come off.

  Here, it is desirable to transfer to the spray when the droplets are detached. However, a short circuit may occur during the second predetermined time t2 set by the second predetermined time setting unit 22 in response to the falling of the peak current Ip. When a short circuit detection signal Sd (ON) indicating that a short circuit has occurred is output by the short circuit detection unit 24 during the second predetermined time t2, as shown in FIG. The feeding speed switching unit 20 is switched to the wire feeding speed WF3 setting unit 25 side in which the wire feeding speed is further reduced from the wire feeding speed WF2, and the wire feeding speed is further reduced to the wire feeding speed WF3. Minimize spatter generation. When the wire feed speed WF2 is reverse feed, when the short circuit detection signal Sd (ON) is output, control is performed so that the reverse feed amount of the wire feed increases.

  Thereafter, after the short circuit is opened and the short circuit detection signal Sd is terminated by the short circuit detection unit 24 (the short circuit detection signal Sd is OFF), the switching control unit 27 switches the wire feed speed switching unit 20 to the wire feed speed WF1 setting unit. Switch to the 18th side. As a result, the amount of spatter generated can be suppressed.

(Embodiment 6)
The sixth embodiment will be described with reference to FIG. 10 and FIG. In the sixth embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. FIG. 10 is a diagram showing a schematic configuration of a consumable electrode type DC pulse arc welding machine according to the sixth embodiment. FIG. 11 is a time chart of pulse welding current and wire feed speed in the sixth embodiment. The main difference from the first embodiment is that a short-circuit detection unit 24 is provided and the wire feed speed is switched based on the detection of the short-circuit.

  During the wire preheating period, the wire feeding speed is set on the wire feeding speed WF1 setting unit 18 side, and is peaked by the pulse current pulse time setting unit 14 while feeding the welding wire 9 at the wire feeding speed WF1. The output of the current Ip is started. The switching control unit 27 receives the rising of the peak current Ip set by the pulse current pulse time setting unit 14, and after the first predetermined time t1 set by the first predetermined time setting unit 19 has elapsed, The feeding speed switching unit 20 is switched to the wire feeding speed WF2 setting unit 21 side. The wire feed speed WF2 is set to a value lower than the wire feed speed WF1. Alternatively, the wire feeding speed WF2 is set to the wire feeding speed for reverse feeding.

  After that, the pulse current pulse time setting unit 14 continues to output the peak current Ip. When the peak current period Tp elapses, the pulse current pulse time setting unit 14 shifts to the base current period Tb in which the base current Ib is output, thereby reducing the arc reaction force. Drops come off.

  However, in the case where the next peak current Ip is output without completing the detachment of the droplet during the base current period, the wire feed speed WF1 is set to the wire feed speed WF1 setting unit 18 side. A short circuit may occur while the welding wire 9 is being fed.

  Therefore, in the sixth embodiment, a short circuit detection signal Sd that means that a short circuit has occurred by the short circuit detector 24 while the wire feed speed switching unit 20 is switched to the wire feed speed WF1 setting unit 18 side. When (ON) is output, the switching control unit 27 switches the wire feeding speed switching unit 20 to the wire feeding speed WF2 setting unit 21 side to smoothly open the short circuit.

  Thereafter, after the short circuit is opened and the short circuit detection signal Sd is terminated by the short circuit detection unit 24 (the short circuit detection signal Sd is OFF), the switching control unit 27 switches the wire feed speed switching unit 20 to the wire feed speed WF1 setting unit. The wire feed speed WF1 setting unit 18 side is continued until switching to the 18 side and receiving the next rising of the peak current Ip.

  Thereafter, the switching control unit 27 receives the rise of the next peak current Ip set by the pulse current pulse time setting unit 14, continues the wire feed speed WF1 until the first predetermined time t1 elapses, When the predetermined time t1 of 1 elapses, the wire feeding speed is set to the wire feeding speed WF2, and the falling of the peak current Ip set by the pulse current pulse time setting unit 14 is received, and when the second predetermined time t2 elapses, The wire feed speed is returned from the wire feed speed WF2 to the wire feed speed WF1.

  As described above, according to the sixth embodiment, it is possible to minimize the amount of spatter generated even when the regularity of droplet detachment is disturbed, for example.

  In the sixth embodiment, the wire feed speed WF2 may be lower than the wire feed speed WF1, which is the feed speed at the time of rising of the peak current Ip, or the welding wire 9 is used as the base material. It is good also as a reverse feed which feeds in the direction pulled away from 10.

  It should be noted that the first to sixth embodiments described above may be implemented in appropriate combination.

  In the present invention, the arc length can be kept as short as possible, welding defects such as undercuts are hardly generated, the amount of spatter can be reduced, and a good bead appearance can be obtained. This is industrially useful as a pulse arc welding control method to be performed.

DESCRIPTION OF SYMBOLS 1 3 phase alternating current input 2 Primary side rectifier 3 Smoothing capacitor 4 Switching part 5 Welding transformer 6 Secondary side rectifier 7 Reactor 8 Welding tip 9 Welding wire 10 Base material 11 Wire feed motor 12 Voltage detector 13 Voltage setting part 14 Pulse Current pulse time setting section 15 Current detector 16 Inverter drive circuit 17 Wire feed motor drive circuit 18 Wire feed speed WF1 setting section 19 First predetermined time setting section 20 Wire feed speed switching section 21 Wire feed speed WF2 setting Unit 22 Second predetermined time setting unit 23 Droplet separation detection unit 24 Short circuit detection unit 25 Wire feed speed WF3 setting unit 26 Arc 27 switching control unit

Claims (8)

A pulse arc welding control method for repeatedly supplying a peak current and a base current in a pulsed manner between a welding wire and a welding object,
During a predetermined period from the first time point during the peak current period to the second time point during the base current period, the feeding speed of the welding wire is set lower than the feeding speed at the rising edge of the peak current. Alternatively, a pulse arc welding control method in which the welding wire is fed backward in a direction in which the welding wire is pulled away from the welding object. The pulse arc welding control method according to claim 1, wherein the first time point is a time point when a first predetermined time has elapsed from a rising time point of the peak current. The pulse arc welding control method according to claim 2, wherein the first predetermined time is different for each pulse period or is the same for each pulse period. The pulse arc welding control method according to any one of claims 1 to 3, wherein the second time point is a time point at which a second predetermined time has elapsed from a falling time point of the peak current. 5. The pulse arc welding control method according to claim 4, wherein when the detachment of the droplet is detected, the feeding speed is returned to the feeding speed before the change without waiting for the elapse of the second predetermined time. 6. A short circuit between the welding wire and the welding object during the second predetermined time is detected, the feeding speed of the welding wire is further reduced, or the reverse feed amount of the welding wire is further increased. The pulse arc welding control method described in 1. The pulse arc welding control method according to any one of claims 1 to 6, wherein the predetermined period is a period shorter than the peak current period. When the welding wire is being fed at the same feeding speed as the feeding speed at the time of rising of the peak current, if a short circuit between the welding wire and the welding object is detected, the feeding speed of the welding wire is 8. The pulse arc according to claim 1, wherein the pulse arc is set to be lower than a feeding speed at a rising point of a peak current, or reverse feeding is performed so that the welding wire is fed away from the welding object. Welding control method.

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