KR0167180B1 - Generating power controller for arc welder - Google Patents

Abstract

The present invention relates to an output control apparatus for a short-circuit arc transition type welding power source. In the related art, an electric current of an optimum pattern according to a shield gas type, a base material, and a material of a material is formed by performing a current control of a predetermined pattern in accordance with a welding current regulation during a short circuit. It is difficult to secure good welding quality by not performing control, and by performing open loop constant voltage control during arcing, it is not possible to prevent the spatter generated at the beginning of arcing and to respond to changes in load conditions. Defective welding quality is deteriorated because it may not be able to bring the stability of the arc, and judges both short circuit and arc at the time of short circuit and arc judgment by short circuit and arc judgment voltage. There is a problem that causes. Therefore, the present invention separates the setting part of the initial short circuit and the final current slope at the time of short-circuit and the conversion point setting part of the two slopes, so that the optimum current pattern is set at the time of short-circuit despite the conversion of welding conditions by substrate, material, and gas. In the arc, the arc initial welding current abatement setting part is provided, and the arc abruptly reduces the current to the abatement setting value at the beginning of arc transition, and then controls the welding voltage to feedback constant voltage to suppress spatter generation and increase arc stability. By determining the short circuit and the arc by two comparison reference voltage values due to hysteresis when the short circuit / arc is judged, the possibility of short circuit / arc judgment error during low current welding is reduced, and the welding quality can be improved.

Description

Output control device of short-circuit arc transition type welding power supply

1 is a block diagram of an output control apparatus of a conventional short-circuit arc transition type welding power supply.

2 is a waveform diagram of welding voltage and welding current in FIG.

Figure 3 is a block diagram of the output control device of the present invention short-circuit arc transition type welding power supply.

4 is a welding voltage and welding current waveform diagram in FIG.

5 is an enlarged view of the welding current waveform in FIG.

* Explanation of symbols for main parts of the drawings

1: rectification smoothing part 12: load voltage detection part

11: inverter drive unit 15: welding voltage setting unit

13: voltage / current control switching unit 16: welding current setting unit

19: wire supply control unit 20: welding voltage detection unit

22: current sudden abrupt value setting unit 23: sudden abrupt value reaching determination unit

24: voltage control unit 25: primary current slope setting unit

26: secondary current slope setting unit 27: current control unit

28: current slope conversion point setting unit 29: conversion point arrival determination unit

The present invention relates to a short-circuit arc transition type welding apparatus for improving the welding quality by improving the stability of the welding arc and reducing the spatter, especially the short-circuit initial and the last current slope setting unit at the time of short-circuit, respectively. By setting the conversion point setting part of the two slopes separately, it is possible to set the optimum current pattern during short-circuit despite the change of welding condition by base material, material, and gas. And an output control device for a short-circuit arc-conducting welding power supply which reduces the generation of spatters and increases the arc stability by controlling the welding voltage by feedback constant voltage after sharply reducing the voltage to a sudden reduction set value.

The conventional output control device of the short-circuit arc transition type welding power supply includes a power supply unit 100 for supplying a DC voltage obtained by rectifying the applied AC power to the wire supply device, as shown in FIG. Detects the voltage supplied from the power supply unit 100 to the wire feeder, and determines whether it is a short circuit state or an arc state during welding, and according to the determination result, the current supply and voltage control are performed on the power supply unit 100 to set the load value. And a wire supply unit 300 to determine the wire supply speed according to the welding current set by the controller 200 and to supply the wire according to the determined speed.

The power supply unit 100 is rectified with respect to the three-phase AC power input to the first rectifier (1) for converting and outputting the DC voltage, and smoothed with respect to the DC voltage output through the first rectifier (1) The smoothing part 2, the inverter part 3 which converts the direct current smoothed by the smoothing part 2 into the high frequency alternating current, and the high frequency alternating current of the inverter part 3 are transformed into the AC low voltage suitable for welding, A transformer 4 for outputting and a second rectifying section 5 for rectifying the output of the transformer 4 again with a DC voltage and outputting it through the current smoothing reactor 6.

The controller 200 may include a load voltage detector 12 that detects a load voltage from a load when welding is performed by repeating short circuiting and arcing from tens to hundreds (Hz), and a current detector that detects a current from the load ( 7) and a short circuit / arc judging unit 14 which compares the load voltage detected by the load voltage detecting unit 12 with the short / arc judging voltage to determine whether it is a short circuit state or an arc state, and a current control during short circuit. When inputting the welding current setting unit 16 for setting the welding current setting value to be performed, and when the welding current setting value of the welding current setting unit 16 is short-circuit When short-circuit by product A current controller 18 and a current controller 18 to follow the current pattern set by the current pattern setter 17 at the time of short-circuiting of the current value detected by the current detector 7 and Perform voltage control The welding voltage setting unit 15 for setting the welding voltage set value for the purpose, and the welding voltage setting unit for arcing the output of the current control unit 18 when the short circuit / arc determination unit 14 determines that the output is short. The inverter of the power supply unit 100 according to the voltage / current control switching unit 13 for selecting and outputting the welding voltage set value of 15) and the voltage or current value input through the voltage / current control switching unit 13. It consists of an inverter drive unit 11 to control the control to be a welding power source.

In addition, the wire supply unit 300 is a wire supply control unit 19 for determining the wire supply speed according to the welding current setting value set in the welding current setting unit 16, and the supply speed of the wire supply control unit 19 And a torch 9 for welding the wire to the base metal 10 to be welded with the wire fed through the wire feeder 8 and the wire fed through the wire feeder 8.

Looking at the conventional technology configured as described above are as follows.

The three-phase AC power is input to the first rectifying unit 1 of the power supply unit 100 and is primarily rectified, so that the DC voltage is smoothed by the capacitor of the smoothing unit 2.

When the smoothed DC voltage is converted into high frequency AC by the inverter unit 3 and is transformed into an AC low voltage suitable for welding by the transformer 4 and transferred to the second rectifier 5, the second rectifier 5 ) Rectifies the AC low voltage of the transformer 4 back to DC, and outputs the same to the wire supply unit 8 through the current smoothing capacitor 6.

The reason why the inverter unit 3 converts into high frequency alternating current is because the core cross-sectional area of the main transformer 4 is inversely proportional to the frequency. Thus, the power supply unit 100 is reduced by reducing the size and weight of the main transformer 4. It is to reduce the size and weight.

At this time, the operation of the controller 200 is as follows.

Short-circuit arc-type welding is a load voltage detection part when the short circuit and arc phenomenon are repeated from several tens to several hundreds (Hz) like the welding current waveform of (b) of FIG. 2 between the wire end and the base material continuously fed. In (12), the load voltage as in (a) of FIG. 2 is detected.

From the load voltage waveform shown in (a) of FIG. 2 detected by the load voltage detector 12, the short circuit time increases gradually as the welding current increases at a low level, and the arc time welds at a high voltage level. It can be seen that as the current decreases, it gradually decreases.

Therefore, the short / arc determination unit 14 receives the load voltage transmitted from the load voltage detection unit 12 and compares the predetermined voltage value, that is, the short / arc determination voltage shown in (a) of FIG. If it is lower than the short / arc determination voltage, it is determined as a short circuit T1, or an arc T2.

When the short / arc judging unit 14 determines whether the load state is a short circuit or an arc, and outputs the voltage / current control switching unit 13 to the voltage / current control switching unit 13, the voltage / current control switching unit 13 performs the current control at the time of short circuit. In order to carry out, switching to the output side of the current control unit 18 is performed.

Then, the short circuit and arc time control are as follows.

When the short circuit outputs the welding current setting value set by the welding current setting unit 16 to the current pattern setting unit 17 during the short circuit, the current pattern setting unit 17 during the short circuit is weld current patterns classified according to products. Is determined and the determined welding current pattern is output to the current control unit 18.

Therefore, the current controller 18 compares the welding current pattern of the current pattern setting unit 17 at the time of short-circuit with the current of the current detector 7 detecting the current flowing through the load, and the detected current follows the welding current pattern. The current value to be provided is provided to the voltage / current control switching unit 13.

The output of the current control unit 18 is applied to the voltage / current control unit switching unit 13 so that the voltage / current control switching unit 13 switches to the current control side at the time of short circuit according to the determination result of the short circuit / arc determination unit 14. As it is switched, it is transmitted to the inverter driver 11 and accordingly the inverter unit 3 of the power supply unit 100 is driven so that the current pattern set by the current pattern setting unit 17 when the short-circuit utility current is short-circuited. To follow.

Then, the open loop constant voltage control is performed by outputting the welding voltage set by the arc-cyene welding voltage setting unit 15 to the voltage / current control switching unit 13.

That is, the output of the welding voltage setting unit 15 is applied to the voltage / current control switching unit 13 so that the arc-time voltage / current control switching unit 13 receives the voltage according to the determination result of the short circuit / arc determination unit 14. As it is switched to the control side, it is transmitted to the inverter driver 11 and the inverter 3 is driven accordingly so that the set value of the arc welding voltage setting unit 15 is applied to the load.

On the other hand, the wire supply control unit 19 of the wire supply unit 300 determines the supply speed according to the welding current set value set by the welding current setting unit 16 and outputs to the wire supply unit 8, the wire feed The supply part 8 supplies a wire to the torch 9 at a feeding speed to be delivered.

Therefore, the torch 9 is welded to the required portion of the base material 10 to be welded.

The welding current pattern at the time of short circuit affects the shape of the welding bit and spatter generation, that is, welding quality.

In addition, it is known that the optimum welding current pattern at the time of short circuit according to the type of shield gas, the material of the base material and the material of the material is not the same.

Therefore, the prior art classifies the short-circuit arc transition welding power supply into MIG, CO2, and MAG in order to perform the current control of the optimum pattern according to the type of shield gas, the material of the base material, and the material of the material during short circuit. Optimal welding current patch control is performed in case of short-circuit by product, but basically, MIG, CO2 and MAG welding power supply are the same.

In order to obtain good welding quality by the short-circuit arc transition type welding power source, the arc should not be interrupted during welding, that is, ensuring the stability of the arc and reducing the spatter is the key. The open loop (OPEN LOOP) constant voltage control is performed. The method alone does not prevent the spatter generated during arcing.

It is known that spatter generated at this time can be significantly reduced by drastically reducing the welding current at the beginning of the arc.

Therefore, a control method capable of drastically reducing the welding current in the arc initial stage is required.

In addition, the open loop constant voltage control alone may not bring about good stability of the arc when the load conditions such as the operator's vibration or the weld's bending are not well compensated for.

Therefore, a control method is required to achieve the required voltage compensation when the welding load conditions change.

However, in the conventional short-circuit arc transition type welding, in the form of the load voltage, when the short circuit occurs, the load voltage gradually increases with the increase of the welding current, and during the arc, the load voltage increases with the decrease of the welding current from the high value. It can be seen that the decrease.

In particular, the lower the diameter of the wire, the longer the wire protruding length in the low current welding, the greater the increase in the load voltage according to the increase in the welding current in the short circuit, the prior art is as shown in (a) of FIG. When judging both short circuit and arc by one comparative voltage value (short / arc judgment voltage) at low current welding, voltage control should be performed due to the judgment error which is actually judged by arc period or short circuit, but by T3 and The same arc anxiety period occurs.

On the other hand, if the comparison voltage is further lowered, an error which is determined as an arc during a short circuit period can be made, which in turn causes instability of the arc.

Such arc instability causes a large amount of spatters, as well as a decrease in welding quality, so there is a problem in judging both short circuits and arcs with one comparison voltage value.

Accordingly, an object of the present invention to solve the above problems is to determine the possibility of a short circuit / arc determination error during low current welding by judging the short circuit or arc by two comparison reference voltage values due to hysteresis when the short circuit / arc judgment by the load voltage The present invention provides an output control apparatus for a short-circuit arc transition type welding power supply to reduce welding.

Another object of the present invention is to separate the current slope setting unit for setting the initial short circuit and the final current slope at the time of short-circuit and the conversion point setting unit of the two current slopes in spite of the change of welding condition by base material, material, and gas. It is to provide the output control device of short-circuit arc transition type welding power supply which enables users to set MIG and CO2 and MAG welding with only one power supply device by setting and controlling the optimum current pattern at the time.

Still another object of the present invention is to provide the arc initial arc current welding current abrupt value setting portion to reduce the spatter generated during arc by feedback control to abruptly reduce the welding current at the initial arc transition to the abrupt set value, by controlling the feedback voltage constant feedback The present invention provides an output control device for a short-circuit arc transition type welding power source that increases the arc stability since the welding voltage is compensated for the bending of the weld or the vibration of the operator.

The output control device of the present invention, the short-circuit arc transition type welding power supply for achieving the above object, as shown in Figure 3, the power supply for supplying the DC voltage obtained by rectifying the applied AC power supply as a welding power supply Determination unit 400 that determines whether the load is a short circuit state or an arc state by comparing the load voltage applied to the load with the hysteresis arc and the short-circuit determination voltage, respectively, and determines the short circuit through the determination unit 400. Setting current 600 to set the welding current and the short-circuit initial and final short-circuit current slope at the time of arcing, and to determine the welding voltage and the current sudden decrease value at the time of arcing, and compares the current slope change point set point according to the welding current at the short-circuit with the actual current. And the current / voltage control unit 700 to control the current to the primary slope by the initial short circuit or the secondary slope by the last short circuit. The welding power adjusting unit 500 for controlling the welding power supplied to the load by the current / voltage of the current / voltage controller 700 and the wire according to the welding current set by the setting unit 400 according to the determination result of 400. The supply speed is determined, and the wire supply unit 300 is configured to perform welding by supplying a wire according to the determined speed.

The determination unit 400 is a load voltage detection unit 12 for detecting a voltage supplied from the power supply unit 100 to the load, the short circuit determination voltage and arc determination by the load voltage and hysteresis of the load voltage detection unit 12 The hysteresis short circuit / arc judging section 21 determines whether the load is in a short circuit state or an arc state by comparing voltages, respectively.

In addition, the welding power supply adjusting unit 500 switches the inverter driving unit 11 for driving the inverter unit 3 to the current or voltage control side during a short circuit or an arc determined by the determination unit 400. It consists of a switching part 13.

In addition, the setting unit 600 is a welding voltage / current setting unit 15, 16 for setting the welding current and the welding voltage during short circuit and arc, and the first slope or short circuit by the initial short circuit according to the welding current at the time of short circuit It consists of the primary and secondary current slope setting parts 25 and 26 which set the secondary slope by the end, and the arc current ramp value setting part 22 for setting an arc current ramp value.

The current / voltage control unit 700 compares the welding voltage detection unit 20 that detects the welding voltage supplied to the load, and the voltage control unit when the actual current is greater than the current sudden reduction value by comparing the arc sudden current abrupt value and actual rectification. (24) outputs the welding voltage in the zero state so that the welding current can be drastically reduced, and if the actual current is small, the voltage controller 24 causes the voltage of the welding voltage setting unit 15 and the welding voltage detection unit ( The sudden decrease value determination unit 23 outputs a determination signal to control the voltages of the same 20, and the welding voltage set in accordance with the control output of the sudden decrease value determination unit 23 and the voltage of the welding voltage detection unit 20. The voltage control unit 24 which performs constant voltage control so as to coincide with this, the current gradient conversion point setting unit 28 for setting the current slope conversion point according to the set welding current, and the conversion set value of the current slope conversion point setting unit 28 and the actual By comparing the current, and controlling the current to be controlled by the primary current slope when the actual current is smaller than the conversion set value, and outputting a control signal to perform the current control by the secondary current slope when the actual current is large. 29) and a current control unit 27 for controlling and outputting the current detected by the current detection unit 7 in accordance with the control signal of the conversion point arrival determination unit 29.

When described in detail with respect to the operation and effect of the present invention configured as described above.

When a three-phase AC power is input to the first rectifying unit 1 of the power supply unit 100, the first rectifying unit 1 rectifies the input AC power to make a DC voltage, and the smoothing unit receives the DC voltage. In (2), a capacitor is used to output a smoothed and smooth DC voltage.

The smoothed DC voltage is converted into high frequency AC by the inverter unit 3, and is transformed into an AC low voltage suitable for welding by the transformer 4 and transferred to the second rectifying unit 5. ) Rectifies the AC low voltage of the transistor former 4 back to DC and outputs the same through the current smoothing capacitor 6.

Then, the short-circuit arc transition type welding has short-circuit and arc phenomena from tens to hundreds [Hz] like the welding current waveform shown in (b) of FIG. 4 between the wire tip and the base material, which is continuously fed from the wire supply section 8. It is repeated and welding is made.

At this time, the load voltage detection unit 12 of the determination unit 400 detects the load voltage as shown in (a) of FIG.

It can be seen from the load voltage waveform of FIG. 4 (a) that the short circuit time increases gradually as the welding current increases at a low level, and the arc time gradually decreases as the welding current decreases at a high level. have.

When the load voltage of the load voltage detection unit 12 is input to the hysteresis short circuit / arc judging unit 21, it is determined whether a short state or an arc state.

That is, the hysteresis short circuit / arc judging section 21 shows that the welding load voltage Vwel is higher than this in FIG. Judging by the paragraph.

Here, the configuration of the hysteresis short circuit / arc judging unit 21 uses a single power supply comparator as shown in FIG. 6 (b), where Vref is a reference voltage as a value between Varc and Vshort.

The output voltage Vo of the comparator has one of two values, Vsat or ZERO of FIG. 6 (a). Vsat is a value close to the power supply voltage + B of the comparator, and Varc and Vshort is defined as in the following equations (1) and (2).

Therefore, Varc and Vshort can be arbitrarily adjusted by properly setting the Vref and the resistance ratio n.

By the operation of the comparator, the output voltage Vo of the comparator becomes Vsat when the input voltage Vwel is larger than the above-defined Varc, and becomes zero when Vwel is smaller than Vshort.

The voltage / current control switching unit 13 of the welding power supply adjusting unit 500 switches the output voltage Vo of the hysteresis short circuit / arc judging unit 21 to Vsat, that is, the arc surface voltage control side to output the voltage control unit 24. If the output voltage Vo is zero (zero), that is, a short circuit, the output voltage Vo is switched to the current control side and the output of the current control unit 27 is applied to the inverter driver 11.

As a result, in Fig. 6 (a), the transition determination reference voltage Varc of the short circuit in the short circuit is different from the arc-short transition determination reference voltage Vshort in the arc. Since it is set higher than the reference voltage (Vshort) from the transition to the short circuit, it can be seen from the welding load voltage waveform that a determination error is not made even when the wire diameter is small and the wire length is long when welding low current. .

When the hysteresis short circuit / arc judging section 21 determines that the short circuit is outputted to the voltage / current control switching section 13, it operates as follows to control the waveform in the section T1 of FIG.

When the welding current set by the welding current setting unit 16 of the setting unit 600 is short-circuited, the current slope conversion point setting unit 28 of the current / voltage control unit 700 sets the current slope conversion point setting value according to the welding current. The conversion point arrival determination unit 29 outputs the result.

Then, the conversion point arrival determination unit 29 compares the output of the current detection unit 7 with the current slope conversion point setting value of the current slope conversion point setting unit 28, and when the actual current is smaller than the conversion point setting value, the current is changed to the primary current slope. A signal is sent to the current control unit 27 to perform control, and a signal is sent to the current control unit 27 so as to perform current control with a secondary current slope when the actual current is larger than the set point.

Accordingly, the current controller 27 controls the input current detected by the current detector 27 by the signal from the conversion point arrival determiner 29 to the primary or secondary current slope to control the voltage / current control procedure. Output to the affected part 13.

At this time, as determined by the short circuit, the voltage / current control switching unit 13 is switched to the current control unit 27 and the inverter driver 11 controls the inverter unit 3 according to the current value transmitted therefrom.

The two current slopes can be set separately in order to respond to changes in welding conditions by base metal, material, and gas, and by lowering the secondary current slope below the primary current slope, This is to reduce the spatter generated.

Arc time control is to control like the waveform in the section T2 of FIG. 5. Looking at this, when the current sudden value set by the arc current abrupt value setting unit 22 is outputted to the abrupt value reaching determination unit 23. The abrupt value arrival determination unit 23 receives the arc sudden current abrupt value and the actual current value of the current detector 7 and compares them. When the actual current is greater than the abrupt value, the voltage controller 24 causes the voltage controller 24 to provide a welding voltage. Is applied to zero to output a determination signal to the voltage controller 24 so that the welding current can be drastically reduced. If the actual current is smaller than the sudden decrease of the current, the voltage controller 24 causes the welding voltage setting unit 15 to be reduced. Outputs a determination signal to the voltage controller 24 to control the voltage of the same with the voltage of the welding voltage detector 20.

According to the signal of the sudden decrease value determination unit 23, when the actual current is smaller than the current sudden decrease value, the voltage of the welding voltage setting unit 15 may match the voltage of the welding voltage detection unit 20. FEED BACK constant voltage control.

The reason for sharply reducing the welding current during arcing is to reduce the spatter generated at the beginning of the arc transition, and the reason for performing the feedback constant voltage control is to increase the arc stability.

On the other hand, the wire supply speed is determined by the wire supply control unit 19 of the wire supply unit 300 determines the supply speed according to the welding current setting value set in the welding current setting unit 16, and outputs to the wire supply unit 8, The wire supply unit 8 supplies the wire to the torch 9 at a feeding speed to be transmitted.

Therefore, the torch 9 is welded to the required portion of the base material 10 to be welded.

As described in detail above, the present invention separates the setting part of the initial short circuit and the last current slope at the time of short-circuit and the conversion point setting part of the two inclinations in the event of short-circuit in spite of the change of base material, material, gas, and welding conditions. The optimum current pattern can be set and controlled.In case of arc, the arc initial welding current drop setting section is used to reduce the generation of spatter and increase the arc stability by controlling the welding voltage to feedback constant voltage. When short / arc is judged by load voltage, short circuit and arc are judged by two comparison reference voltage values by hysteresis to reduce the possibility of short-circuit / arc decision error during low current welding and improve welding quality. There is.

Claims (9)

The power supply unit 100, which supplies the DC voltage obtained by rectifying the applied AC power as a welding power source, and compares the load voltage applied to the load with the hysteresis arc and the short-circuit determination voltage, respectively, to determine whether the load is in a short state or an arc state. Determination unit 400 for determining, and a setting unit for setting the welding current and the initial short-circuit and the current short-circuit current slope when judged to be a short circuit through the determination unit 400 and the setting of the welding voltage and the current sudden decrease in the arc when judged as arc (600) and the current / voltage control unit 700 to compare the current slope conversion point set value according to the welding current in the short circuit and the real current to perform the current control to the primary slope by the initial short circuit or the secondary slope by the last short circuit. And, welding power adjustment for controlling the welding power supplied to the load by the current / voltage of the current / voltage control unit 700 according to the determination result of the determination unit 400 And a wire supply unit 300 to determine the wire supply speed according to the welding current set by the setting unit 600 and to supply the wire according to the determined speed. Output control device for short-circuit arc transition type welding power supply. According to claim 1, The determination unit 400 is a load voltage detection unit 12 for detecting a voltage supplied from the power supply unit 100 to the load, and the short circuit determination by the load voltage and hysteresis of the load voltage detection unit 12 An output control apparatus for a short-circuit arc transition type welding power source, comprising: a hysteresis short-circuit / arc judging unit 21 for comparing a voltage and an arc judging voltage to determine whether a load is in a short-circuit state or an arc state. 3. The output control apparatus according to claim 2, wherein the hysteresis short circuit / arc judging section comprises a short power comparator. The method of claim 1, wherein the welding power supply adjusting unit 500 switches to the inverter driving unit 11 for driving the inverter unit 3 and the short circuit or arc time determined by the determination unit 400 to the current or voltage control side. An output control device for a short-circuit arc transition type welding power source, characterized in that it comprises a voltage / current control switching unit (13). According to claim 1, wherein the setting unit 600 is a welding voltage / current setting unit (15) (16) for setting the welding current and the welding voltage during short circuit and arc, and by the initial short circuit according to the welding current at the time of short circuit To the primary and secondary current slope setting units 25 and 26 for setting the primary slope or the secondary slope at the end of the short-circuit, and the arc current ramping unit 22 for setting the arc current ramp. An output control device for a short-circuit arc transition type welding power source, characterized in that the configuration. According to claim 1, the current / voltage control unit 700 is compared with the welding voltage detection unit 20 for detecting the welding voltage supplied to the load, the arc-time current abrupt value and the actual rectification compared to the actual current abrupt value If the flow rate is large, the voltage controller 24 outputs the welding voltage in zero state so that the welding current can be drastically reduced. If the actual current is small, the voltage controller 24 causes the welding voltage setting unit 15 to The welding voltage and the welding voltage set according to the control output of the abrupt value reaching determination unit 23 and the sudden output reduction determination unit 23 for outputting a determination signal to control the voltage and the voltage of the welding voltage detection unit 20 to be equal. A voltage controller 24 which performs constant voltage control so that the voltages of the detector 20 match, a current gradient conversion point setting unit 28 for setting a current gradient conversion point according to the set welding current, and the current slope conversion point setting unit 28 Of The conversion point that compares the conversion set value and the real current and outputs a control signal to perform current control with the primary current slope when the actual current is smaller than the conversion set value, and performs the current control with the secondary current slope when the actual current is large. Short-circuit-arc transition characterized in that it consists of an arrival determination unit 29 and a current control unit 27 for controlling and outputting the current detected by the current detection unit 7 in accordance with the control signal of the conversion point arrival determination unit 29. Output control device of the welding power source. 7. The output control apparatus of a short-circuit arc transition type welding power supply according to claim 6, wherein the secondary current slope and the primary current slope correspond to changes in welding conditions by base material, material, and gas. 8. The output control apparatus according to claim 7, wherein the secondary current slope is lower than the primary current slope to reduce the spatter generated in proportion to the current peak value during the short circuit. 7. The output control apparatus for a short-circuit arc transition type welding power supply according to claim 6, wherein the voltage control section performs feedback constant voltage control.