JPH0531577A - Method and device for controlling output of consumable electrode arc welding machine - Google Patents

Abstract

PURPOSE:To furnish the output control method and device of the consumable electrode arc welding machine capable of detecting feed abnormality of a welding wire, avoiding the occurrence of buckling, burn-back, etc., of the above- mentioned welding wire and preventing surely malfunction at the time of changing the feed rate of the welding wire. CONSTITUTION:A motor rotating speed set value increase detector 7 outputs a signal, which is made to 'L' only for the specified time when the increase of a motor rotating speed set value given to a motor drive control circuit 3 is detected. Meanwhile, a comparator 8 compares a current value (If) carried to a wire feed motor 5 with a limit current value (Ir) to detect overload of the wire feed motor 5. An AND circuit 9 calculates AND of the output of the motor rotating speed set value increase detector 7 and the comparator 8. A control circuit 10 turns off a switch 2 and a welding power source 11 when the output of this AND circuit 9 attains a 'H' level.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a function of detecting a feeding abnormality of a consumable electrode (hereinafter referred to as a welding wire) and stopping a welding operation, thereby preventing buckling and burnback of the welding wire. The present invention relates to a method and an apparatus for controlling the output of a consumable electrode type arc welder provided.

[0002]

2. Description of the Related Art In a consumable electrode type arc welding machine, a welding wire is fed to a torch portion through a feeding tube and welding power is supplied to the torch portion to generate an arc for welding. ing. Generally, the inner diameter of the feed tube is set to be slightly larger than the outer diameter of the welding wire, and due to bending of the feed tube and clogging of the welding wire in the feed passage due to accumulation of shavings, welding If the feeding is continued with the wire feeding resistance increased, the welding wire may buckle. In particular, buckling is likely to occur in the case of a soft welding wire made of aluminum or the like. Further, the fluctuation of the wire feed amount may cause the arc to become unstable and cause burnback, and the arc may burn up to the tip, and the welding wire and the tip may be fused. In order to avoid such a situation, in the consumable electrode type arc welding machine, the current flowing through the wire feeding motor is detected, the overload of the motor due to the wire feeding abnormality is detected, and burnback occurs. An output control device is provided to stop the welding operation before.

FIG. 6 is a block diagram showing an output control device of the conventional consumable electrode type arc welding machine.

The welding wire 12 is supplied to the welding torch by a pair of feeding rolls 14 which are rotationally driven by the wire feeding motor 5. Welding power is supplied from the welding power source 11 to the welding torch, and the tip of the welding wire 12 and the base metal 1
Welding is performed by generating an arc between 3 and 3.

The welding wire feeding motor 5 is driven by the motor drive circuit 3 based on the set value of the rotation speed setting device 1. A switch 2 is interposed between the rotation speed setting device 1 and the motor drive control circuit 3, and a current detector 4 is interposed between the motor drive control circuit 3 and the wire feeding motor 5. Has been done.

The comparator 8 for comparing the output of the current detector 4 with the value set in the limiter current value setting device 6 outputs the result to the control circuit 10 via the switch 15.

The control circuit 10 is a circuit for controlling the start and stop of welding work, and is adapted to turn on / off the switch 2, the timer 16 and the power supply 11. The timer 16 is set to a time that is slightly longer than the time required for the rotation speed to stabilize after the wire feeding motor 5 starts rotating.

Next, the operation of the conventional output control device of the consumable electrode type arc welding machine configured as described above will be described.

First, when welding is started, the power source 11 is turned on to start welding power supply to the welding torch, and the switch 2 is closed to set the motor drive control circuit at the value set in the rotation speed setting device 1. 3 drives the wire feeding motor 5. The timer 16 also starts operating. As a result, the welding wire 12 is fed to the welding torch at a predetermined speed, and welding power is supplied to the welding torch from the power source 11 to carry out welding. In this case, the overload signal is output from the comparator 8 at the start of rotation of the wire feeding motor 5, but at this time, since the switch 15 is off, the overload signal is not transmitted to the control circuit 10. . After that, after the wire feeding motor 5 reaches the steady rotation, the timer 16 times up and the switch 15 is turned on.

After that, the comparator 8 compares the output of the current detector 4 for detecting the current flowing in the wire feeding motor 5 with the limiter current value set in the limiter current value setting device 6,
The comparison result is given to the control circuit 10 via the switch 15. Normally, the limiter current value set in the limiter current value setting unit 6 is larger than the current flowing in the wire feeding motor 5, so the control circuit 10 keeps the switch 2 and the power supply 11 in the ON state.

However, for some reason, the welding wire 12
Is not fed at a predetermined speed, an overcurrent flows in the wire feeding motor 5 and the comparator 8 outputs an overload signal. This overload signal is output to the control circuit 10 via the switch 15, and the control circuit 10 turns off the switch 2 to stop the power supply to the wire feeding motor 5, and at the same time, the power supply 11
To turn off the supply of welding power,
Prevent buckling and burnback of 2.

However, in the conventional output controller for a consumable electrode type arc welding machine, the horizontal axis represents time and the vertical axis represents the motor current of the wire feeding motor 5, as shown in FIG. Although an increase in the motor current at the time of starting the feed motor 5 is not judged as an overload and a malfunction can be prevented, the wire feed motor 5 is changed by changing the welding conditions.
If the number of revolutions increases, the motor current increases as at startup, and if the number of revolutions increases sharply, the motor current will be the limiter current even if overload does not actually occur. There is a problem that the limiter current value set in the value setter 6 is exceeded and the overload is erroneously determined to stop the welding operation. In addition, the commercial power supply voltage is 180-200V ± 1
It fluctuates within a range of about 0V. Due to this voltage fluctuation, the output of the current detector 4 may fluctuate, and as a result, the comparator 8 may malfunction and output an overload signal to stop the welding operation.

Therefore, there has been proposed an output control device for a consumable electrode type arc welder capable of measuring a change in the motor rotation speed and distinguishing an actual overload from an increase in the motor rotation speed. Fairness 3-4309).

FIG. 8 shows a block diagram of the output control device of the consumable electrode type arc welding machine described in Japanese Patent Publication No. 3-4309. In addition to the overload detector 41 similar to the above-mentioned conventional technique, an acceleration detector 42
Is provided and outputs the output of the motor speed detector 46 to the differentiator 47.
The differential value discriminator 48 determines whether the motor is in an accelerating state or a decelerating state. Then, on the basis of the outputs of the overload detector 41 and the acceleration detector 42, it is discriminated whether it is overload or when the rotation speed of the motor is increased, and the welding operation is stopped only in the case of overload.

At the time of starting the motor and increasing the wire feeding speed during operation, the motor current value Ia> the limiter current value Ir and the speed differential value α> 0. Also,
At the time of steady rotation and deceleration of the motor, the motor current value Ia <
In addition to the limiter current value Ir, the velocity differential value α ≦ 0. Further, in the case of overload, the motor current value Ia> the limiter current value Ir and the speed differential value α ≦ 0. In this way, it is possible to distinguish between an actual overload and an increase in the number of rotations of the motor.

[0016]

[Problems to be Solved by the Invention]
In the output control device for a consumable electrode type arc welding machine disclosed in No. 3-4309, the horizontal axis represents time, and the vertical axis represents the rotation speed of the motor. As shown in FIG. The rotation rising speed is slower than the motor current rising speed. Therefore, when the interlock circuit 49 detects an increase in the motor rotation speed, the motor current value has already exceeded the limiter current value, and the output of the overload detection circuit becomes valid, causing a malfunction and stopping the welding work. Will end up.

In order to avoid such a malfunction, it is conceivable to provide the motor current detector with a smoothing circuit having a time constant corresponding to the time required for the rotation of the motor to rise. Detection will be delayed if a load occurs. This delay in overload detection causes bending of the welding wire and clogging of the tip or the like even if the welding wire does not buckle.

The present invention has been made in view of the above problems, and it is possible to reliably detect an abnormality in the feeding of the welding wire and avoid the occurrence of inconveniences such as buckling and burnback of the welding wire. An object of the present invention is to provide an output control method and device for a consumable electrode type arc welder capable of preventing malfunctions when the feed motor rotation speed is increased.

[0019]

An output control method for a consumable electrode type arc welding machine according to the present invention is a consumable electrode type arc welding machine for performing welding while feeding a welding wire to a welding portion by a wire feeding motor. In the output control method, an overload signal is output when the current flowing through the wire feeding motor exceeds a limiter current value, and the wire is output based on the overload signal when the motor rotation speed setting value has not increased. The driving of the feed motor and the welding power source is stopped, and when the set value of the motor rotation speed is increasing, the operation due to the overload signal is blocked for a predetermined period.

The output control device of the consumable electrode type arc welding machine according to the first invention device of the present application controls the output of the consumable electrode type arc welding machine for performing welding while feeding the welding wire to the welding portion by the wire feeding motor. In the apparatus, a rotation speed setting device that sets a rotation speed of the wire feeding motor, a driving unit that drives the wire feeding motor based on a rotation speed setting value set in the rotation speed setting device, and the welding device. A welding power supply for supplying welding power between the wire and the weld,
An overload signal generating means for detecting a current flowing through the wire feeding motor, comparing the current with a limiter current value, and generating an overload signal for stopping the operation of the driving means and the welding power source based on the result; A rotation speed set value increase detection means for detecting an increase in the rotation speed set value; and the drive by the overload signal for a predetermined period when the rotation speed set value increase detection means detects an increase in the rotation speed set value. Means and overload signal control means for preventing the stopping operation of the welding power source.

Further, the output control device of the consumable electrode type arc welding machine according to the second invention device of the present application is the consumable electrode type arc welding machine for performing welding while feeding the welding wire to the welding portion by the wire feeding motor. In the output control device, drive control means for rotationally controlling the wire feeding motor based on a predetermined rotation speed set value, a welding power supply for supplying welding power between the welding wire and the welding portion, and the wire. A command signal output means for outputting a command signal for increasing the rotation speed setting value of the feed motor to the drive control means, and a current flowing through the wire feed motor are detected and compared with a limiter current value to obtain the result. An overload signal generating means for generating an overload signal for stopping the operation of the drive control means and the welding power source based on the above, and the overload signal generating means for a predetermined period when the command signal is output. And having a overload signal control means for inhibiting said drive control means and a welding power source stop with load signal.

[0022]

In the method of the present invention, the overload signal is output when the current flowing through the wire feeding motor exceeds the limiter current value. At this time, if the set value of the motor rotation speed is not increased, the drive of the wire feeding motor and the welding power source is stopped based on the overload signal, and if the set value of the motor rotation speed is increased. Stopping the drive of the wire feeding motor and the welding power source based on the overload signal for a predetermined period. That is, in the method of the present invention, when the motor rotation speed setting value is increasing, it is not determined that the motor is substantially overloaded, and for example, a period sufficient for the rotation speed of the wire feeding motor to stabilize. Make sure that the wire feeding motor and welding power source do not stop. On the other hand, when the current flowing through the wire feeding motor increases and an overload signal occurs even though the motor rotation speed setting value has not increased, the driving of the wire feeding motor and the welding power source is stopped. As a result, it is possible to reliably avoid buckling, burnback, etc. of the welding wire, and prevent malfunctions when the wire feeding motor is started and when the welding wire feeding speed is changed.

In the first invention device of the present application, the rotational speed set value increase detecting means for detecting an increase in the rotational speed set value of the wire feeding motor is provided. Then, the overload signal control means invalidates the output of the overload detection means only for a predetermined period after the rotation speed set value increase detection means detects the increase in the rotation speed set value. As a result, it is possible to prevent a malfunction when the rotation speed of the wire feeding motor is increased. Further, when the current flowing through the wire feeding motor increases without detecting the increase in the rotation speed setting value, the driving of the wire feeding motor and the welding power source is stopped by the overload signal. Thus, it is possible to reliably detect the feeding error of the welding wire, and it is possible to reliably avoid buckling and burnback of the welding wire.

In the second invention device of the present application, the wire feeding motor is rotationally driven by the drive control means on the basis of a predetermined rotation speed set value, and the rotation speed set value is outputted from the command signal generating means. It is designed to increase according to the output command signal. When this command signal is output, the overload signal control means prevents the drive control means and the welding power source from stopping due to the overload signal for a predetermined period. As a result, it is possible to prevent a malfunction when the number of rotations of the welding wire feeding motor is increased and to detect a welding wire feeding abnormality.

The predetermined time period is determined according to the increase amount of the rotational speed set value, so that the current stop value of the wire feeding motor exceeds the limiter current during the stop operation stop time due to the overload signal. It can be approximately equal to time. Therefore, it is preferable that the predetermined period is determined according to the increase amount of the rotation speed setting value.

[0026]

Embodiments of the present invention will now be described with reference to the accompanying drawings.

FIG. 1 is a block diagram showing an output control device of a consumable electrode type arc welding machine according to a first embodiment of the present invention.

A predetermined motor rotation speed set value is set in the rotation speed setter 1, and the motor drive control circuit 3 drives the wire feeding motor 5 based on this set value, and a pair of predetermined rotation speeds are set. The welding wire 1 is rotated by rotating the feeding roll 14.
2 is supplied to the welding torch. Also, this welding wire 12
, Welding power is supplied from the power source 11, and an arc is generated with the base material 13.

A current detector 4 is interposed between the motor drive control circuit 3 and the wire feeding motor 5 to detect the current flowing through the wire feeding motor 5. A switch 2 is interposed between the rotation speed setting device 1 and the motor drive control circuit 3 described above. Further, the motor rotation speed set value increase detector 7 detects an increase in the motor rotation speed set value provided to the motor drive control circuit 3 via the switch 2.

The comparator 8 compares the output signal If of the current detector 4 with the limiter current value Ir set in the limiter current value setting unit 6. This limiter current value Ir is
It is set to a value slightly larger than the current that flows when the motor 5 is in steady rotation. The AND circuit 9 calculates the logical product of the output S1 of the comparator 8 and the output signal S2 of the motor rotation speed set value increase detector 7. The control circuit 10 turns off the switch 2 and the power supply 11 when the output signal S3 of the AND circuit 9 becomes "H" level.

FIG. 2 is a block diagram showing details of the motor rotation speed set value increase detector 7. The motor rotation speed set value increase detector 7 is set in a differentiation circuit 21 that inputs the motor rotation speed setting value a and differentiates and outputs the motor rotation speed setting value a, an output signal b of the differentiation circuit 21 and a reference value setting device 24. It is composed of a comparator 22 for comparing the reference value and the one-shot circuit 23 to which the output signal c of the comparator 22 is given.

FIG. 3 is a timing chart showing the operation of the motor rotation speed set value increase detector 7. When the motor rotation speed setting value a increases, the differentiating circuit 21 outputs an output signal b corresponding to the increase in the motor rotation speed setting value a. When the output signal b exceeds the value set in the reference value setting unit 24, the comparator 22 outputs the “H” level as the output signal c. The output signal S2 of the one-shot circuit 23 is
It goes to "L" level for a predetermined time from the rising of the signal c. The pulse width of the output pulse of the one-shot circuit 23 is set to be slightly longer than the time required for the rotation speed of the wire feeding motor 5 to stabilize.

Next, the operation of the output control device of the consumable electrode type arc welding machine according to the present embodiment constructed as described above will be described.

At the start of welding, the switch 2 and the power source 11 are turned on, and the motor rotation speed setter 1 supplies the motor rotation speed set value to the motor drive control circuit 3. The motor drive control circuit 3 drives the wire feeding motor 5 based on the motor rotation speed setting value. At the start of rotation of the wire feeding motor 5, a relatively large current flows, so that the output signal If of the current detector 4 exceeds the limiter current value Ir set in the limiter current value setter 6.
Therefore, the output signal S1 of the comparator 8 becomes "H" level. On the other hand, the motor rotation speed set value increase detector 7 outputs the "L" level as the output signal S2 at the start of welding in order to detect the change in the motor rotation speed set value. Therefore,
The output signal S3 of the AND circuit 9 becomes "L" level.

After that, when the rotation of the wire feeding motor 5 becomes stable and becomes a steady state, the output signal If of the current detector 4 becomes lower than the limiter current value Ir, and the output signal S1 of the comparator 8 becomes "L". Become a level. Therefore, even if the output signal S2 of the motor rotation speed set value increase detector 7 becomes "H" level, the output of the AND circuit 9 remains "L" level.

When welding is carried out in a steady state, the wire feed motor 5 is rotating based on the rotation speed set value set in the rotation speed setting device 1, whereby the welding wire 12 is kept constant. It is fed toward the base material 13 at a speed.
Further, in this case, the motor rotation speed set value increase detector 7
The output of is maintained at "H" level.

At this time, assuming that the welding wire 12 is being fed smoothly, the output signal If of the current detector 4
Is lower than the limiter current value Ir set in the limiter current value setter 6. Therefore, the output signal S1 of the comparator 8
Is at the "L" level, and the output signal S3 of the AND circuit 9 also maintains the "L" level.

When the feeding speed of the welding wire 12 is increased, the motor rotation speed set value given from the rotation speed setting device 1 to the motor drive control circuit 3 is increased. This allows
The current flowing from the motor drive control circuit 3 to the wire feeding motor 5 increases, and the rotation speed of the wire feeding motor 5 increases. At this time, the motor rotation speed set value increase detector 7 detects an increase in the motor rotation speed set value and sets the output signal S2 to the "L" level for a predetermined time. In addition, the current detector 4
Output signal If exceeds the limiter current value Ir, the output signal S1 of the comparator 8 becomes "H" level. Therefore,
The output of the AND circuit 9 maintains the "L" level. After that, when the number of rotations of the wire feeding motor 5 becomes stable and becomes a steady state, the output If of the current detector 4 becomes the limiter current value Ir.
The output of the comparator 8 becomes "L" level. Then, the output signal S2 of the motor rotation speed set value increase detector 7 becomes "H" level. Therefore, even if the wire feeding speed is increased, the output signal S3 of the AND circuit 9 is "L".
It is maintained at the level, and it is possible to prevent the welding work from being stopped due to a malfunction.

On the other hand, if the welding wire 12 is not fed smoothly, the wire feeding motor 5 becomes overloaded,
The output signal If of the current detector 4 exceeds the limiter current value Ir. As a result, the output signal S1 of the comparator 8 becomes "H" level. At this time, since the output signal S2 of the increase detector 7 is at "H" level, the output signal S3 of the AND circuit 9 is at "H" level. Therefore, the control circuit 10
Turns off the switch 2 and the power supply 11. This allows
The welding work is stopped.

In this embodiment, the motor rotation speed set value increase detector 7 detects a change in the motor rotation speed set value, and when the set value increases, the signal S1 from the comparator 8 is invalidated. As a result, it is possible to reliably prevent erroneous operation when the rotational speed of the wire feeding motor 5 is increased, and it is possible to reliably avoid occurrence of inconveniences such as buckling and burnback of the welding wire 12. Also,
Since the malfunction at the time of changing the rotation speed of the wire feeding motor 5 can be surely prevented, it is only necessary to set the limiter current value to be slightly higher than the motor current in the steady state, which increases the feeding resistance of the wire feeding path. Can be reliably detected. Further, for example, a smoothing circuit having a large time constant is not required, a wire feeding abnormality can be detected at an early stage, and clogging of the chip due to buckling of the wire can be avoided.

In this embodiment, the increase in the motor rotation speed set value is detected by the motor rotation speed set value increase detector 7, and the output of the comparator 8 when the rotation speed of the wire feeding motor 5 is increased. Although the case of invalidating is described, the rotation speed of the wire feeding motor 5 may be controlled by using a microcomputer. In this case, for example, a command signal for increasing the motor rotation speed setting signal is given from the CPU (central processing unit) to the motor drive control circuit 3. In addition to providing a circuit that outputs "L" level for a predetermined period when this command signal is output,
By providing the current detector, the comparator, and the like, the same effect as that of the above-described embodiment can be obtained.

FIG. 4 is a block diagram showing a motor rotation speed set value increase detector of the output control device of the consumable electrode type arc welding machine according to the second embodiment of the present invention.

The present embodiment is different from the first embodiment in that the configuration of the motor rotation speed set value increase detector is different, and other configurations are basically the same as those in the first embodiment.

This motor rotation speed set value increase detector is
It is configured by a signal differentiating circuit 30 to which a signal delay element is added, a reference value setting device 31 for setting a reference value, and a comparator 32 for comparing the output signal b of the differentiating circuit 30 with the reference value.

FIG. 5 is a timing chart showing the operation of the motor rotation speed set value increase detector. When the increase amount of the motor rotation speed set value a is large, the amplitude of the output signal b of the differentiating circuit 30 becomes relatively large as shown by the solid line, and the comparator 32 outputs a pulse having a large pulse width as the output signal S2. To do. On the other hand, the motor rotation speed set value a
If the amount of increase in the signal is small, as shown by the broken line, the amplitude of the output signal b of the differentiating circuit 30 is small, and the comparator 32 outputs a pulse having a short pulse width as the output signal S2.

That is, in the first embodiment, after the increase in the set value is detected, the signal S2 is set to the "L" level for a certain period, whereas in the present embodiment, the motor rotation speed set value a is changed. The "L" level period of the signal S2 is changed according to the increase amount.

In this embodiment, the invalid period of the overload detection signal can be minimized in response to the difference in the motor acceleration period due to the difference in the increase amount of the motor rotation speed set value. As a result, there is an effect that the control for preventing the wire buckling can be performed more effectively while preventing the malfunction.

[0048]

As described above, according to the present invention, the drive of the wire feeding motor and the welding power source is stopped when the overload signal is output even though the set value of the motor rotation speed is not increased, When an overload signal is output while the set value of the motor rotation speed is increasing, the wire feed motor and the welding power source are prevented from being stopped for a predetermined period of time. It is possible to avoid the inconvenience and to prevent the welding work from being stopped due to a malfunction when the wire feeding speed is changed.

[Brief description of drawings]

FIG. 1 is a block diagram showing an output control device of a consumable electrode type arc welder according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing the motor rotation speed set value increase detector.

FIG. 3 is a timing chart showing an operation of the motor rotation speed set value increase detector.

FIG. 4 is a block diagram showing a motor rotation speed set value increase detector of the output control device of the consumable electrode type arc welder according to the second embodiment of the present invention.

FIG. 5 is a timing chart showing the same operation.

FIG. 6 is a block diagram showing an output control device of a conventional consumable electrode type arc welder.

FIG. 7 is a graph showing a change with time of a current flowing through a wire feeding motor.

FIG. 8 is a block diagram showing an output control device of another conventional consumable electrode type arc welder.

FIG. 9 is a graph showing the same problem.

[Explanation of symbols]

1; Rotation speed setting device 2,15; switch 3; Motor drive control circuit 4; Current detector 5; Wire feeding motor 6; Limiter current value setting device 7: Motor rotation speed set value increase detector 8,22,32; comparator 9; AND circuit 10; Control circuit 11; power supply 12; Welding wire 16; Timer 21, 30; differentiating circuit 23; One-shot circuit 24; Reference value setting device

Claims (4)

[Claims] 1. In an output control method of a consumable electrode type arc welder for performing welding while feeding a welding wire to a welding portion by a wire feeding motor, a current flowing through the wire feeding motor exceeds a limiter current value. When an overload signal is output and the set value of the motor speed has not increased, the drive of the wire feed motor and welding power source is stopped based on this overload signal, and the set value of the motor speed increases. The output control method of the consumable electrode type arc welder is characterized in that the above-mentioned operation due to this overload signal is blocked for a predetermined period when the arc welding machine is operating. 2. An output control device for a consumable electrode type arc welder that performs welding while feeding a welding wire to a welding portion by a wire feeding motor, and a rotation speed setting device for setting the rotation speed of the wire feeding motor. A driving means for driving the wire feeding motor based on the rotation speed set value set in the rotation speed setting device; a welding power supply for supplying welding power between the welding wire and the welding portion; Overload signal generating means for detecting the current flowing through the wire feeding motor, comparing it with a limiter current value, and generating an overload signal for stopping the operation of the driving means and the welding power source based on the result, Rotation speed set value increase detection means for detecting an increase in the rotation speed set value, and the overload for a predetermined period when the rotation speed set value increase detection means detects an increase in the rotation speed set value. An output control device for a consumable electrode type arc welding machine, comprising: the driving means by a load signal and an overload signal control means for preventing a stopping operation of the welding power source. 3. An output control device for a consumable electrode type arc welder which performs welding while feeding a welding wire to a welding portion by a wire feeding motor, wherein the wire feeding motor is controlled based on a predetermined rotational speed setting value. Outputting to the drive control means a drive control means for rotationally driving control, a welding power supply for supplying welding power between the welding wire and the welding portion, and a command signal for increasing the rotation speed set value of the wire feeding motor. And a command signal output means for detecting the current flowing through the wire feeding motor, comparing this with a limiter current value, and based on the result, an overload signal for stopping the operation of the drive control means and the welding power source. Overload signal generating means for generating, and an overload signal for preventing a stop operation of the drive control means and the welding power source by the overload signal for a predetermined period when the command signal is output. And an output control device of the consumable electrode type arc welding machine. 4. The output control device for a consumable electrode type arc welder according to claim 2, wherein the predetermined period is determined according to an increase amount of the rotation speed set value.