Method for controlling completion of welding in consumable electrode arc-welding

Abstract

To appropriately perform control of completion of welding corresponding to various welding conditions, in consumable electrode arc-welding.SOLUTION: In a method for controlling completion of welding in consumable electrode arc-welding, in which when a welding-completion signal On is inputted to a welding power source at time t1, a processing period is transferred to a welding-completion processing period at time t2, and welding currents Iw, in which peak currents in a peak period and base currents in a base period are distributed in one cycle, are repeatedly distributed in predetermined cycles to complete welding in the welding-completion processing period, welding voltages Vw at the time t2 at which the processing period is transferred to the welding-completion processing period are detected, and heat input is increased and decreased in the welding-completion processing period, in accordance with the detected welding voltages Vw at the time at which the processing period is transferred.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a method for controlling the end of consumable electrode arc welding. [Background technology]

[0002] In consumable electrode arc welding, welding end control (anti-stick control) is performed to optimize the distance between the tip of the welding wire and the base metal at the end of welding to prevent the welding wire from sticking to the molten pool, and to optimize the size of the wire tip grains formed at the end of welding to improve the next arc start. When a welding end signal is input to the welding power source, the welding end processing period begins. This is an inertia period during which the feed motor decelerates transiently due to inertia and stops, and the welding current and welding voltage are controlled.

[0003] Patent Documents 1 and 2 disclose a method for controlling the end of consumable electrode arc welding, in which a peak current and a base current are passed in one cycle to end welding when a welding end signal is input to a welding power source. Patent Document 1 is for the case where the consumable electrode arc welding is DC arc welding. Patent Document 2 is for the case where the consumable electrode arc welding is pulse arc welding. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2007-313513 A [Patent Document 2] JP 2012-130961 A Summary of the Invention [Problem to be solved by the invention]

[0005] When the arc length changes during the transition to the welding end processing period due to welding conditions such as the distance between the power contact tip and the base metal, the welding position, and the welding voltage setting, the distance between the tip of the welding wire and the base metal at the end of welding and the grain size at the tip of the welding wire change. For example, if the arc length is longer than the appropriate range, the distance between the tip of the welding wire and the base metal at the end of welding will be longer than the appropriate value, and the tip grain size will also be larger than the appropriate size, which will result in poor arc startability for the next time. Conversely, if the arc length is shorter than the appropriate range, the distance between the tip of the welding wire and the base metal at the end of welding will be shorter than the appropriate value, and the tip grain size will also be smaller than the appropriate size, which will also result in poor arc startability for the next time.

[0006] Therefore, an object of the present invention is to provide a method for controlling the end of welding in consumable electrode arc welding, which can optimize the distance between the tip of the welding wire and the base metal and the tip grain size at the end of welding, even if the arc length varies when transitioning to the welding end processing period. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems, the invention of claim 1 comprises: When a welding end signal is input to the welding power source, the welding end processing period begins. In the welding termination control method for consumable electrode arc welding, during the welding termination processing period, a cycle of passing a peak current during a peak period and a base current during a base period is set as one cycle, and the welding is terminated by repeating the cycle for a predetermined period, Detecting a welding voltage at the time of transition to the welding end processing period; increasing or decreasing the heat input during the welding termination process period in response to the detected welding voltage at the time of the transition; The present invention relates to a method for controlling the end of consumable electrode arc welding.

[0008] The invention of claim 2 is as follows: The heat input is increased or decreased by increasing or decreasing at least one value of the peak period, the peak current, the base period, and the predetermined cycle. 2. The method for controlling a welding termination in consumable electrode arc welding according to claim 1,

[0009] The invention of claim 3 is as follows: When the arc welding is pulse arc welding, an average value of the welding voltage during a predetermined period immediately before the transition is detected as the welding voltage at the time of the transition; 3. The method for controlling a welding termination in consumable electrode arc welding according to claim 1 or 2. Effect of the Invention

[0010] According to the method for controlling the welding termination of consumable electrode arc welding of the present invention, even if the arc length varies when transitioning to the welding termination processing period, the distance between the tip of the welding wire and the base metal and the tip grain size at the end of welding can be optimized. [Brief description of the drawings]

[0011] [Figure 1] 1 is a block diagram of a welding power source PS for carrying out a method for controlling a welding finish in consumable electrode arc welding according to a first embodiment of the present invention. [Diagram 2] 2 is a timing chart of each signal in the welding power source of FIG. 1, illustrating the welding termination control method for consumable electrode arc welding according to the first embodiment of the present invention. [Diagram 3] FIG. 11 is a block diagram of a welding power source PS for carrying out a method for controlling the welding finish in consumable electrode arc welding according to a second embodiment of the present invention. [Figure 4] 5 is a timing chart of each signal in the welding power source of FIG. 3, illustrating a welding termination control method for consumable electrode arc welding according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0013] [Embodiment 1] In the first embodiment, the arc welding is DC arc welding.

[0014] 1 is a block diagram of a welding power source PS for carrying out a method for controlling the welding finish in consumable electrode arc welding according to a first embodiment of the present invention. Each block will be described below with reference to the diagram.

[0015] The power supply main circuit PM receives a commercial power supply (not shown) such as a three-phase 200V commercial power supply, performs output control such as inverter control according to a drive signal Dv described below, and outputs a welding voltage Vw and welding current Iw suitable for arc welding. Although not shown, the power supply main circuit PM includes a primary rectifier circuit that rectifies the commercial power supply, a capacitor that smoothes the rectified DC, an inverter circuit driven by the drive signal Dv described above that converts the smoothed DC into high-frequency AC, a high-frequency transformer that steps down the high-frequency AC to a voltage value suitable for arc welding, a secondary rectifier circuit that rectifies the stepped-down high-frequency AC into DC, and a reactor that smoothes the rectified DC.

[0016] The welding wire 1 is fed through the welding torch 4 by the rotation of a feed roll 5 connected to a feed motor M, and an arc 3 is generated between the welding wire 1 and the workpiece 2. A welding voltage Vw is applied between the welding wire 1 and the workpiece 2, and a welding current Iw flows between the welding wire 1 and the workpiece 2. A shielding gas (not shown) is ejected from the tip of the welding torch 4. The shielding gas may be argon gas, a mixed gas of argon gas and carbon dioxide gas, a mixed gas of argon gas and oxygen, or the like.

[0017] The welding start / end circuit ON outputs the welding start / end signal On, which goes to High level (welding start signal) when welding starts and to Low level (welding end signal) when welding ends. This circuit is a switch attached to the welding torch 4. In the case of robot welding, this circuit is also built into the robot control device.

[0018] The welding current setting circuit IR outputs a predetermined welding current setting signal Ir.

[0019] The feed speed setting circuit FR receives the above-mentioned welding current setting signal Ir as an input, and outputs a feed speed setting signal Fr calculated using a predetermined current-feed speed conversion function.

[0020] The feed control circuit FC receives the above-mentioned welding start / end signal On and the above-mentioned feed speed setting signal Fr as inputs, feeds the welding wire 1 at a constant speed at the feed speed Fw set by the feed speed setting signal Fr when the welding start / end signal On is at a high level (welding start signal), and outputs a feed control signal Fc for stopping the feed motor M when the welding start / end signal On changes to a low level (welding end signal). When the welding start / end signal On changes to a low level (welding end signal), the feed speed Fw gradually decelerates due to inertia and stops. This deceleration period is the inertia period.

[0021] The rotation speed of the feed motor M is controlled by the feed control signal Fc, and the welding wire 1 is fed at a feed speed Fw.

[0022] The welding voltage setting circuit VR outputs a predetermined welding voltage setting signal Vr. The welding voltage detection circuit VD detects the welding voltage Vw and outputs a welding voltage detection signal Vd. The voltage error amplifier circuit EV amplifies the error between the welding voltage setting signal Vr and the welding voltage detection signal Vd and outputs a voltage error amplification signal Ev.

[0023] The transition welding voltage detection circuit VED receives the above-mentioned welding voltage detection signal Vd and a switching control signal Sc described later, and outputs the value of the welding voltage detection signal Vd at the time when the switching control signal Sc changes to a low level as a transition welding voltage detection signal Ved. The transition welding voltage detection signal Ved is the value of the welding voltage Vw at the time when the welding ends, and detects the arc length at the time of transition.

[0024] The pulse current setting circuit IPR receives as input the transition welding voltage detection signal Ved and the switching control signal Sc described below, and outputs a pulse current setting signal Ipr which repeats the peak current setting value during the peak period and the base current setting value during the base period for a predetermined period from the point in time when the switching control signal Sc changes to a low level, and outputs a stop signal Off which goes to a high level for a short time when the repetition ends. 1) When the value of the transition welding voltage detection signal Ved is within a predetermined appropriate range, the peak period, the peak current setting value, the base period and the specified cycle each become a predetermined reference value. 2) When the value of the transition welding voltage detection signal Ved is greater than the appropriate range, at least one of the following values ​​is modified: the peak period is decreased by a predetermined value from the reference value, the peak current set value is decreased by a predetermined value from the reference value, the base period is increased by a predetermined value from the reference value, and the predetermined period is decreased by a predetermined value from the reference value. 3) When the value of the transition welding voltage detection signal Ved is smaller than the appropriate range, at least one of the following values ​​is modified: the peak period is increased by a predetermined value from the reference value, the peak current set value is increased by a predetermined value from the reference value, the base period is decreased by a predetermined value from the reference value, and the predetermined period is increased by a predetermined value from the reference value.

[0025] The welding current detection circuit ID detects the above-mentioned welding current Iw and outputs a welding current detection signal Id. The current error amplifier circuit EI amplifies the error between the above-mentioned pulse current setting signal Ipr and the welding current detection signal Id and outputs a current error amplified signal Ei.

[0026] The arc period measurement circuit TA measures the elapsed time of the arc period from the point in time when the short circuit is released and the arc re-strikes, and outputs an arc period measurement signal Ta.

[0027] The switching control circuit SC receives the above welding start / end signal On and the above arc period measurement signal Ta as inputs, and outputs a switching control signal Sc which changes to a high level when the welding start / end signal On changes to a high level (welding start), and changes to a low level when the value of the arc period measurement signal Ta becomes equal to the value of a predetermined delay time Td after the welding start / end signal On changes to a low level (welding end). The delay time Td is about 5 ms, and may be set to 0 seconds so that there is no delay.

[0028] The switching circuit SW receives the voltage error amplified signal Ev, the current error amplified signal Ei, and the switching control signal Sc as inputs, and when the switching control signal Sc is at a high level (steady welding period), it switches to side a and outputs the voltage error amplified signal Ev as the error amplified signal Ea, and when the switching control signal Sc is at a low level (welding end processing period), it switches to side b and outputs the current error amplified signal Ei as the error amplified signal Ea. Therefore, when the switching control signal Sc is at a high level, constant voltage control is performed like a general consumable electrode arc welding power supply, and when it is at a low level, constant current control is performed, and a pulse current formed from a peak current and a base current is passed only in a predetermined cycle.

[0029] The drive circuit DV receives the above welding start / end signal On, the above stop signal Off and the above error amplified signal Ea as inputs, and performs PWM modulation control based on the error amplified signal Ea during the period from when the welding start / end signal On changes to a high level until the stop signal Off changes to a high level for a short time, and outputs the drive signal Dv. Therefore, the welding power source PS starts outputting when the welding start / end signal On changes to a high level, and when the welding start / end signal On changes to a low level and a pulse current of a predetermined cycle is conducted, the stop signal Off goes to a high level for a short time, and stops outputting.

[0030] Fig. 2 is a timing chart of each signal in the welding power source of Fig. 1, which illustrates the method for controlling welding end in consumable electrode arc welding according to the first embodiment of the present invention. Fig. 2(A) shows the change over time of the welding start / end signal On, Fig. 2(B) shows the change over time of the feed speed Fw, Fig. 2(C) shows the change over time of the welding current Iw, Fig. 2(D) shows the change over time of the welding voltage Vw, Fig. 2(E) shows the change over time of the switch control signal Sc, and Fig. 2(F) shows the change over time of the stop signal Off. The operation of each signal will be explained below with reference to the figure.

[0031] At time t1, as shown in Fig. 1(A), when the welding start / end signal On changes from high level (welding start) to low level (welding end), a transition to the welding end processing period (anti-stick control period) occurs. In response to this, the feed motor M in Fig. 1 transitions to a stopping operation, and as shown in Fig. 1(B), the feed speed Fw gradually decelerates due to inertia and becomes 0 at time t4. The period from time t1 to t4 is the inertia period, which is about 40 ms.

[0032] At time t2, when the elapsed time of the arc period from the time when the short circuit that occurred immediately before time t1 was released and the arc was re-ignited reaches a predetermined delay time Td, the switching control signal Sc changes from a high level to a low level as shown in FIG. 1(E). In response to this, a pulse current conduction period is entered, and as shown in FIG. 1(C), the welding current Iw is conducted by repeating a predetermined period in which a pulse current formed from a peak current during the peak period and a base current during the base period is one period. Here, the transition welding voltage detection circuit VED of FIG. 1 detects the welding voltage at the time of transition to the welding end processing period at time t2 as the transition welding voltage detection signal Ved. Alternatively, the welding voltage during the arc period at time t1 may be the transition welding voltage detection signal Ved. Then, the pulse current setting circuit IPR of FIG. 1 sets the values ​​of the peak period, peak current, base period, and predetermined period using the value of the transition welding voltage detection signal Ved as an input. 1) When the value of the transition welding voltage detection signal Ved is within a predetermined appropriate range, the peak period, peak current, base period and predetermined cycle are each set to a predetermined reference value. 2) When the value of the transition welding voltage detection signal Ved is greater than the appropriate range, at least one of the following values ​​is modified: the peak period is decreased by a predetermined value from the reference value, the peak current is decreased by a predetermined value from the reference value, the base period is increased by a predetermined value from the reference value, and the predetermined period is decreased by a predetermined value from the reference value. 3) When the value of the transition welding voltage detection signal Ved is smaller than the appropriate range, at least one of the following values ​​is modified: the peak period is increased by a predetermined value from the reference value, the peak current is increased by a predetermined value from the reference value, the base period is decreased by a predetermined value from the reference value, and the predetermined period is increased by a predetermined value from the reference value. As shown in FIG. 1D, for the welding voltage Vw, a peak voltage during the peak period and a base voltage during the base period are applied between the welding wire and the workpiece. The peak voltage and the base voltage are proportional to the arc length. For example, the appropriate range is 22 to 26 V. The reference value of the peak period is 1.2 ms, and the predetermined value of increase or decrease is 0.2 ms. The reference value of the peak current is 450 A, and the predetermined value of increase or decrease is 30 A. The reference value of the base period is 9 ms, and the predetermined value of increase or decrease is 2 ms. The reference value of the predetermined cycle is 4, and the predetermined value of increase or decrease is 1. The base current is 50 A.

[0033] At time t3, when the supply of the pulse current of the predetermined period ends, the stop signal Off goes to a high level for a short time, as shown in FIG. 1(F). In response to this, the welding power source stops outputting, so that the welding current Iw becomes 0 A, as shown in FIG. 1(C), and the welding voltage Vw becomes 0 V, as shown in FIG. 1(D). In FIG. 1, time t3 is immediately before time t4, when the inertia period of the feed speed Fw ends, but it may also be immediately after time t4. Time t3 is a time close to time t4.

[0034] The effects of the first embodiment will be described below. According to the first embodiment, the welding voltage at the time of transition to the welding finishing processing period is detected, and the heat input during the welding finishing processing period is increased or decreased depending on the detected welding voltage at the time of transition. By detecting the welding voltage at the time of transition to the welding finishing processing period, the arc length at the time of transition is detected. The larger the detected welding voltage, the longer the arc length at the time of transition. Therefore, by increasing or decreasing the heat input during the welding finishing processing period depending on the arc length at the time of transition, the distance between the welding wire tip and the base metal and the tip grain size at the time of welding completion can be optimized.

[0035] More preferably, according to the first embodiment, the heat input is increased or decreased by increasing or decreasing at least one of the peak period, the peak current, the base period, and the predetermined cycle. In this way, the heat input during the welding completion processing period can be optimized according to the arc length at the time of transition. As a result, in the first embodiment, even if the arc length at the time of transition to the welding completion processing period varies, the distance between the welding wire tip and the base metal and the tip grain size at the time of welding completion can be optimized.

[0036] [Embodiment 2] In the second embodiment, the arc welding is pulse arc welding.

[0037] Fig. 3 is a block diagram of a welding power source PS for implementing a method for controlling welding termination in consumable electrode arc welding according to a second embodiment of the present invention. In the figure, the same blocks as those in Fig. 1 are given the same reference numerals and their description will not be repeated. In the figure, a steady peak current modulation circuit IPF is added, a steady pulse current setting circuit IPCR is added, a welding voltage average value detection circuit VAD is added, the transition welding voltage detection circuit VED is replaced with a second transition welding voltage detection circuit VED2, the switching circuit SW is replaced with a second switching circuit SW2, and the current error amplifier circuit EI is replaced with a second current error amplifier circuit EI2, to Fig. 1. Below, these blocks that are different from Fig. 1 will be described with reference to the figure.

[0038] The steady-state peak current modulation circuit IPF receives the voltage error amplified signal Ev, performs modulation control based on the voltage error amplified signal Ev, and outputs a steady-state peak current modulation signal Ipf. This circuit controls the steady-state peak current modulation signal Ipf so that the welding voltage detection signal Vd and the welding voltage setting signal Vr are equal to each other.

[0039] The steady pulse current setting circuit IPCR receives the steady peak current modulation signal Ipf as an input and outputs a steady pulse current setting signal Ipcr that repeats the steady peak current modulation signal Ipf during a predetermined steady peak period and a predetermined steady base current setting value during a predetermined steady base period as one period.

[0040] The welding voltage average detection circuit VAD receives the above-mentioned welding voltage detection signal Vd, calculates an average value for each predetermined period, and outputs the welding voltage average detection signal Vad. The predetermined period is about 1 to 3 cycles of the steady pulse current.

[0041] The second transition welding voltage detection circuit VED2 receives the welding voltage average detection signal Vad and the switching control signal Sc as inputs, and outputs the value of the welding voltage average detection signal Vad at the time when the switching control signal Sc changes to a low level as a transition welding voltage detection signal Ved. The transition welding voltage detection signal Ved is the average value of the welding voltage Vw at the time when the welding ends and detects the arc length at the time of transition.

[0042] The second switching circuit SW2 receives as input the steady pulse current setting signal Ipcr, the pulse current setting signal Ipr, and the switching control signal Sc, and when the switching control signal Sc is at a high level (steady welding period), it switches to side a and outputs the steady pulse current setting signal Ipcr as the current control setting signal Icr, and when the switching control signal Sc is at a low level (welding end processing period), it switches to side b and outputs the pulse current setting signal Ipr as the current control setting signal Icr.

[0043] The second current error amplifier circuit EI2 amplifies the error between the current control setting signal Icr and the welding current detection signal Id, and outputs an error amplified signal Ea. By the above circuit, during the steady welding period, a pulse current whose steady peak current is modulated and controlled based on the steady pulse current setting signal Ipcr is supplied. During the welding end processing period, a pulse current of a predetermined period is supplied based on the pulse current setting signal Ipr.

[0044] Fig. 4 is a timing chart of each signal in the welding power source of Fig. 3, illustrating a method for controlling welding end in consumable electrode arc welding according to embodiment 2 of the present invention. Fig. 4(A) shows the change over time of the welding start / end signal On, Fig. 4(B) shows the change over time of the feed speed Fw, Fig. 4(C) shows the change over time of the welding current Iw, Fig. 4(D) shows the change over time of the welding voltage Vw, Fig. 4(E) shows the change over time of the switch control signal Sc, and Fig. 4(F) shows the change over time of the stop signal Off. The operation of each signal will be explained below with reference to the figure.

[0045] In the figure, the operations after time t2 are the same as those in Figure 2, and therefore the description thereof will not be repeated. Below, the operations before time t2 will be described.

[0046] The period before time t1 is the steady welding period. During the steady welding period, a pulse current formed from a steady peak current during a predetermined steady peak period and a predetermined steady base current during a predetermined steady base period is applied based on the steady pulse current setting signal Ipcr in FIG. 3. The steady peak current is modulated and controlled by the steady peak current modulation signal Ipf in FIG. 3 so that the welding voltage detection signal Vd in FIG. 3 is equal to the welding voltage setting signal Vr in FIG. 3. This controls the arc length to an appropriate value. For example, the steady peak period is 1.2 ms, the steady peak current is modulated and controlled in a range of about 400 to 550 A, the steady base period is 4 ms, and the steady base current is 50 A.

[0047] At time t1, as shown in Fig. 1(A), when the welding start / end signal On changes from high level (welding start) to low level (welding end), a transition to the welding end processing period (anti-stick control period) occurs. In response to this, the feed motor M in Fig. 1 transitions to a stopping operation, and as shown in Fig. 1(B), the feed speed Fw gradually decelerates due to inertia and becomes 0 at time t4. The period from time t1 to t4 is the inertia period, which is about 40 ms.

[0048] At time t2 when the duration of the arc period from before time t1 reaches a predetermined delay time Td, the switching control signal Sc changes from a high level to a low level, as shown in FIG. 1(E). In response to this, the pulse current conduction period of the welding end processing period begins, and as shown in FIG. 1(C), the welding current Iw is conducted by repeating a predetermined period in which a pulse current formed from a peak current during the peak period and a base current during the base period is one period. Here, the second transition welding voltage detection circuit VED2 of FIG. 3 detects the welding voltage at the time of transition to the welding end processing period at time t2 as a transition welding voltage detection signal Ved. Then, the pulse current setting circuit IPR of FIG. 3 sets each value of the peak period, peak current, base period, and predetermined period by inputting the value of the transition welding voltage detection signal Ved. The transition welding voltage detection signal Ved is the average value of the welding voltage during a predetermined period immediately before time t2, and detects the arc length at the time of transition. The predetermined period is 1 to 3 periods of the steady pulse current. The operation after this is the same as FIG. 2.

[0049] According to the second embodiment, when the arc welding is pulse arc welding, the average value of the welding voltage during a predetermined period immediately before the transition is detected as the welding voltage at the transition. This allows the arc length at the transition to be detected. The higher the detected welding voltage, the longer the arc length at the transition. Therefore, by increasing or decreasing the heat input during the welding termination processing period according to the arc length at the transition, the distance between the welding wire tip and the base metal and the tip grain size at the end of welding can be optimized. [Explanation of symbols]

[0050] 1 Welding wire 2 Work 3. Arc 4. Welding torch 5 Feeding roll DV driver circuit Dv drive signal Ea Error amplification signal EI Current Error Amplifier Circuit Ei Current error amplification signal EI2 Second current error amplifier circuit EV voltage error amplifier circuit Ev Voltage error amplified signal FC feed control circuit Fc feed control signal FR feed speed setting circuit Fr feed speed setting signal Fw Feed speed IAD Welding voltage average detection circuit Iad Welding voltage average detection signal Ice current control setting signal ID Welding current detection circuit Id Welding current detection signal IPCR Constant pulse current setting circuit Ipcr Steady pulse current setting signal IPF Constant Peak Current Modulation Circuit Ipf Steady peak current modulation signal IPR Pulse current setting circuit Ipr Pulse current setting signal IR welding current setting circuit Ir Welding current setting signal Iw Welding current M Feed motor Off stop signal ON Welding start / end circuit On Welding start / end signal PM power supply main circuit PS Welding Power Source SC switching control circuit Sc Switching control signal SW switching circuit SW2 2nd switching circuit TA Arc period measurement circuit Ta Arc period measurement signal Td Delay time VD Welding voltage detection circuit Vd Welding voltage detection signal VED Transition Welding Voltage Detection Circuit Ved Transition welding voltage detection signal VED2 Second transition welding voltage detection circuit VR welding voltage setting circuit Vr Welding voltage setting signal Vw welding voltage

Claims

1. When a welding end signal is input to the welding power source, the welding end processing period begins. In the welding termination control method for consumable electrode arc welding, during the welding termination processing period, a cycle of passing a peak current during a peak period and a base current during a base period is set as one cycle, and the welding is terminated by repeating the cycle for a predetermined period, Detecting a welding voltage at the time of transition to the welding end processing period; increasing or decreasing the heat input during the welding termination process period in response to the detected welding voltage at the time of the transition; 2. A method for controlling the end of consumable electrode arc welding.

2. The heat input is increased or decreased by increasing or decreasing at least one value of the peak period, the peak current, the base period, and the predetermined cycle.

2. The method for controlling the end of consumable electrode arc welding according to claim 1.

3. When the arc welding is pulse arc welding, an average value of the welding voltage during a predetermined period immediately before the transition is detected as the welding voltage at the time of the transition; 3. The method for controlling the end of consumable electrode arc welding according to claim 1 or 2.

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