JPS5829575A - Electric power source device for welding - Google Patents

Abstract

PURPOSE:To prevent spatters by transfer to arc generation and to make continuous welding possible by storing the min. voltage in the short circuiting stage and suppressing the short circuiting current when the terminal voltage of a power source device rises higher than the min. voltage. CONSTITUTION:In the short circuiting stage, a trigger circuit 51 instructs a storage device 50 to start storing when the output of a voltage detector 20 drops lower than the output of a setter 53 for reference voltage, thereby storing the min. values of output terminals 100 and 101. A subtractor 54 outputs the difference between the signals of the detector 20 and the device 50. Further, a comparator 55 turns an analog switch 57 on when the output of the subtractor 54 rises higher than the set value of a level setter 56, thereby inputting the signal of a setter 58 for the current in the late period of the short circuiting to an error amplifier 60. The deviation between the signal of the setter 58 and the signal of a current detector 21 is compared and amplified by an error amplifier 60, and the output current is controlled by the current of the setter 58.

Description

[Detailed description of the invention] do.

The process of short-circuit transition welding is shown in Figure 1 (a), (+)), and (C).
Explain using. In Figure 1, (a) shows the voltage waveform during the droplet transfer process (l), and (C) shows the current waveform.
′, ■ “~5”. ■ indicates the arc is occurring, 2 indicates the early stage of the short circuit when the droplet is in contact with the surface of the U material, 3 indicates the middle stage of the short circuit when the short circuit is definitely present, 4 indicates the late stage of the short circuit when the droplet is constricted, and 5 indicates the short circuit is broken. Indicates the moment when arc generation begins, 1
The steps 5 to 5 are repeated.

In this process, it has been revealed that spatter is generated at the moment when the short circuit breaks and an arc is generated, and it has also been revealed that the amount of spatter generated increases when the current during arc regeneration is high. .

Focusing on this cause, attempts have been made to lower the current during arc regeneration, but this has not yet been put to practical use.

No. 2.1974 (referred to as Reference (1)), the large current energization period is limited to the middle period of the welding arc and the final period of σ, and the large current is turned off during the 101st period (L electrode wire and The technology detects the voltage, sets the voltage when the droplet becomes constricted, and controls the program so that the high current period ends when the detected voltage becomes equal to the set voltage, thereby suppressing spatter generation. Disclosed.

However, as described in Reference (1), in practice, the voltage drop during the extension changes depending on the variation in the distance between the torch and the Iu material (extension variation), and the constriction of the droplet This causes an error in the voltage setting value when For this reason, there is an error in the timing at which the large current period ends (1:ji), arcing occurs during the large current period and spatter is generated.There are drawbacks such as difficulty in setting the voltage when the droplet is constricted. .Furthermore, references (
Although not mentioned in 1), there are also error factors such as the voltage drop in the welding cable, the voltage drop at the grounding part, and the voltage drop at the contact part between the contact tip and the electrode wire.

In order to stably reduce spatter, a large current Jtf is required.
It is necessary to accurately determine the termination timing of l71 under various conditions, but as in the past, it is not possible to control the output voltage by controlling the firing angle of the thyristor according to a preset value. Since this cannot be achieved with conventional welding power sources, it has not been put into practical use.

Another problem in practical application is that the short-circuit period is 1msec to 5msec, which is a very short phenomenon, and in order to control this phenomenon, the power supply needs to have a response of 100μs or more. . Although it is difficult to evaluate the responsiveness of the entire power supply, it is necessary to perform feedback at least once every 100 μs.

On the other hand, the above-mentioned three-phase AC 50 (60) I
I7. In conventional power supply devices that control voltage or current using a thyristor, the feedback is 27 to 3. 3
Once every m sec, the response is too slow to be usable.

The present invention eliminates the drawbacks mentioned in 1. In short-circuit transition m-contact, the present invention can accurately determine the end timing of the high current period under various conditions, and has a response speed sufficient to control the short-circuit phenomenon. It is an object of the present invention to provide a welding power supply device that can reduce spatter using a device that has the same structure.

An embodiment of the present invention will be described below with reference to the drawings.

The present invention will be explained in detail using FIGS. 2 and 3. In FIG. 2, 6 is a DC power supply that outputs a predetermined voltage, 7 is a current detector, and 8 is a voltage detector. A contact tip 10 is connected from one terminal of the power supply 6 through a power supply cable 9.
is energized. Welding wire 11 is contact tip 10
An arc 12 is generated between the welding wire 11 and the cutting material 13, but the arc disappears when a short circuit occurs. On the other hand, the other terminal of the power source 6 is connected to the base material 13 using a ground cable 14.

At the time of short circuit, the current is 1 (ampere), the voltage is ■ (volt), the resistance of the power supply cable 9 is R1, the contact resistance between the contact tip 10 and the welding wire 11 is I(2, the resistance in the wire extension is R3, The resistance of the molten part at the tip of the wire is RA, and the contact resistance between the base material and the ground terminal is 1 (
4. If the resistance of the ground cable 14 is 1 (5), the following formula (1
) holds true.

V = T (1-1-R2+R3+R4 to R-A+,
-1-R5) ... (1) 1ζ1 to 15 will vary due to changes in welding location, change in power supply cable length, change in power supply cable temperature, change in ground terminal installation method, etc.
Even during welding, it changes due to variations in the extension. However, during one short circuit period, the short circuit period ranges from 1 n'l sec to 5 rn sec, so it can be considered to be constant.

At this moment RB=R1±R2-1-R3+R4 5 in 10
Then, equation (1) is V = I (RA-1-RB) = VA-t-VB
-(21 Here, VA is the voltage V that drops at the melted part of the wire tip, and n is the voltage that drops in the power supply cable 9 and wire extension mentioned above. The voltage V detected by the voltage detector 8 is This is the sum of VA and vB.

In Fig. 3, time E1 corresponds to the middle period of the short circuit when the short circuit is certain, as shown in 3 in Fig. 1.
2 corresponds to the time after the short circuit when the droplet was constricted as shown in 4 in FIG. 1, and corresponds to time t4(r3', when the arc 1lfi shown in 5 in FIG. 1 is low).

To explain the shortcomings of the prior art again using FIG. 3, under certain conditions (shown by the solid line), the large current period ends when the value detected by the voltage detector 8 becomes equal to VM. When the power supply is driven at 4, the current decreases slightly with a slight delay, but the current decreases before time point 4 and no spatter occurs. However, if the aforementioned R1'% is small due to some kind of enshrinement,
VB becomes smaller, and Ichikawa ■ becomes smaller as shown by the broken line in V-VA-1-VB than in the case of the solid line. For this reason■
The point at which λ4 is reached is point I3, which is immediately before point 4 when the current occurs, so even if the power supply is turned on to end the high current period, a slight delay in the decrease of the current will be the cause. At time L4, a large current is flowing and spatter occurs. [In order to instruct the power supply to end the high current period at point 2, it is necessary to
It is necessary to do it when it becomes. However, wire extensions change after 1 second, so in effect,
It is not possible to change the detection level from VM to VM/.

Therefore, the present invention eliminates the variation in vB due to the variation in RB, and makes it possible to extract only the resistance change of the constriction at the tip of the wire. In FIG. 3, if the voltage Vi at time L1, which indicates the lowest voltage during the short circuit period, is VM, and the voltage at time E2, where constriction occurs, is VM, then VH-= VAL-1-VBL=' (RAL+RB
L) ......(3) VM = VAM-4
-VT3M=I (RA, M-1-RBM)...
-・14. ], and if ΔV-VM-■■-, then △V=VM-Vr-= I (RAM-RA, r-)
+ (RBM-RBI-) (5). P-RM and RBT- are resistances that depend on the power supply cable and wire extension, but the resistance RBM at [10 false low light RBL and L2] is [1 and t
2 interval Δt = t 2 - t 1 is very short. That is, since the short circuit period is 1 m5 ec to 5 m5 ec, it is about 0.5 m5 ec to 2.5 m sec, and 1 (13) changes within this armor time (not exceeding 5" sec at least). and during one short-circuit period, RB = Const and therefore R]HL
-RBM, so equation (5) becomes △■2VM-V I-, = I (艮AM-RAr-)
-VAM-VAr- (6) Equation (6) shows that the difference between the voltage drop at the fused end of the wire at time 11, 3 in Figure 1, and the voltage drop when a constriction occurs at the fused end of the wire, at time 12, 4 in Figure 1, is △V.
, and this △V was detected by a voltage-sparing 1''i device~
This means that it is the difference between 1M and V)-. Therefore, if you memorize ■■7 during the short circuit period, and when the set value △■ with a difference from the subsequent voltage VM is reached, it will be considered as the end of the large current period, and the power supply will be driven to reduce the current. As shown by the solid line in FIG. 3(1)), the current can be lowered before the 14th point, and spatter can be prevented from occurring.

If RB changes when the extension length changes or the welding location changes during welding, and the voltage characteristics change as shown in Figure 3 (a), then equation (7) holds true and △ VM'-V r-'= I (RAM'-r(AL
') -1-I (lJ1'M-R-B r-')...
(7) Also here, for the reason mentioned above, RBM = Rn r- during the short-circuit period of - times, so ΔV'-VM'-
V L'-1(RAMI'-4tA I-') -VA
4-VA I', ts+RA'l-, l<A
Since Q is the resistance of the molten part at the tip of the wire in states 3 and 4 in Fig. 1, respectively, they take the same values as in equations (5) and (6), and RAL = RAl-, RAM = 1'-AM and VAM=VAM, Vhr−=VAr−to(
8) Formula 1riΔv'-vM'-J'-VAM-VAL-
VAM-VAI-Δ(9). Equation (9) is △■
(Δ■, and ΔV always changes, △■′, that is, △
(2) means that it is equal to VM'-vL. The time when the difference between vM' and Vl- becomes equal to Δv' (-ΔV) is at time 12, shown in FIG. By instructing the power supply to terminate the process, the current becomes a solid line instead of the dotted line in FIG.

As explained in Section 1, if VA4dvl- is detected during the short circuit period and the high current period ends when the difference between them becomes equal to the set △V value, the extension 7 By removing the voltage drop caused by external factors caused by changes such as wire tips, etc., only the voltage drop at the wire tip;

11 (Although it may be practical to measure and memorize - immediately after the start of the short circuit, in order to ensure a further reduction in spatter, it is necessary to measure and store the negative value immediately after the point 10 shown in Figure 3 (1)). It is desirable to do this after the short circuit current has reached a nearly constant level.

The short circuit current must be constant, but the average upstream current is 150A.
It is sufficient for practical use if the short circuit current is fixed at 40OA in a case of about 250A. However, if it is preferable to make the short-circuit current variable for special purposes in terms of shot contact, then the following procedure may be used. From equation (6), △V=VM□−Vr−=r(RA
M-RAr-) -・-(101RAM and kAl
- is affected by the wire diameter and wire material, but as long as they are the same, it has a unique constant, so it can be set as RAM-RAL=k.
Equation (10) is ΔV = kI ・River...
(11). Equation (11) means that Δ■ is the short-circuit current value multiplied by the constant k. Therefore, V
The difference between M and Vi detects the short circuit current value, and a constant k is applied to that value.
If the power supply is driven so that the high current period ends when the output becomes equal to △V (=lcI),
Even if the short circuit current changes, spatter can be stably reduced.

There is no point in saying that instead of detecting the short-circuit current, a signal from a reference device or the like for setting the short-circuit current may be used.

In order to control the current and voltage at the time of the short circuit described above, a power source is required that has a response that is 10 times or more the short circuit time 1 ms to 5 ms, that is, a power source that can perform feedback control at least once every 100 μs. FIG. 4 shows one of the power supplies that satisfies this condition. The power supply shown in Fig. 4 is an inverter-type power supply, in which three-phase AC 200V is converted to DC by a rectifier 15, converted to AC of 5 kHz or higher by an inverter 16, and this AC is converted to AC by a transformer 17 for individual welding. After the voltage drops to the same voltage, it is rectified by a rectifier 18 and power is supplied to the contact chip 10 through a reactor 19. A wire 11 is fed through the contact tip 10 and an arc 12 is formed between it and the base material 13. In response to signals from the voltage detector 20 and current detector 21, an inverter control circuit 22 controls the pulse width of the inverter so that desired current and voltage outputs are obtained.

When the frequency of the inverter is 5KTlz, feedback control can be performed twice in one cycle, so feedback can be performed at a rate of 1.15000×2, that is, once every 100 μs. Needless to say, in order to control the short-circuit welding phenomenon, the higher the frequency of the inverter, the more desirable it is.

Examples will be described in further detail below. In Figure 5, commercial frequency three-phase AC (200v) is connected to diodes 23 to 2.
When the base drive circuits 30 and 31 simultaneously turn on the transistors 34 and 35, a current flows in the direction of the arrow on the next side of the transformer 42, and then the base drive circuits 30 and 31 turn on the transistors. After turning off at the same time, the base 1 drive circuit 32.33 turns off the transistor 36.3.
7 is turned on, a current flows through the primary side of the transformer 420 in the direction of arrow B. In this way, the current flows through the transformer 4
The 1s of 2 alternately flow to the next side. This frequency', ()Kl-1z
Perform this at a higher frequency than above. The transformer 42 has an appropriate turns ratio, and a voltage suitable for welding is applied to the transformer 42.
occurs on the secondary side of Here, the diodes 38 to 41 conduct when the primary winding of the transformer 42 becomes equal to or higher than the input voltage, and at the same time, the transistors 34 to 37 are turned off to clamp the primary winding of the transformer 42 so that the voltage does not exceed the input voltage. It has the function of returning the energy stored in the primary winding of the transformer to the input power source.

The secondary output of the transformer 42 is connected to a diode 43 or 4.
6, and is supplied to the contact chip 10 through a reactor 19. When the wire 11 passes through the contact tip 10, power is supplied to the wire 11, and an arc is generated between the wire 11 and the wire 13. Note that the reactor 19 may be omitted in some cases.

The current or voltage at the output terminals 100 and 101 of the inverter is
Time and OJ”F of transistors 34, 35, 36°37
'Adjusted by changing the waiting time ratio.

20 is a voltage detector, and 21 is a current detector.

A circuit for controlling the output of the power supply described above to reduce spatter will be described below.

In FIG. 5, a voltage detector 20 connected to output terminals 100 and 101 outputs a detected voltage signal having a magnitude corresponding to the DC voltage applied between the output terminals 100 and 101.

The output terminal of the voltage detector 20 is connected to one input terminal of an error amplifier 61 that controls the output voltage between the terminals 100 and 101 when an arc occurs, and the other input terminal of the error amplifier 61 is connected to an arc voltage setting device. 62.

On the other hand, current detector 21 still produces a signal proportional to the output current of the power supply. The output terminal of this current detector 21 is connected to one input terminal of an error amplifier 63 for output current control, and the other input terminal of the error amplifier 63 is connected to a short circuit current setting device 64.

The output terminal of each error intensifier 11ffl 61, 63 is connected to the input terminal of a pulse width setter 67 via a diode 65, 66, respectively.

In the above configuration, during arc generation, the signal from the voltage detector 20 and the signal from the voltage setter 62 are compared and amplified by the error amplifier 61, and the error amplification 1 produces a signal proportional to the deviation between the two signals. The signal is diode 65
The pulse width setting device 67 sends a pulse width signal set corresponding to the above deviation to the base drive circuits 30, 31 and 32, 33 alternately. Base drive circuits 30.31 and 32.33 are connected to transistors 34, . 35 and 36.37 are turned on alternately by the aforementioned set pulse width 64.1, the output electric power of the power supply is controlled to the voltage set by the voltage setting device 62.

On the other hand, when a short circuit occurs, the arc disappears and the load impedance rapidly decreases, causing the current to increase. Then, the signal from the current detector 21 and the signal from the current setter 64 are compared and amplified by the error amplifier 63, and input to the pulse width setter 63 through the diode 66. The output current is controlled to be the current specified by short circuit current setting 2 (64).

Further, the output terminal of the voltage detector 20 is connected to a memory 5 which stores the lowest voltage of the voltage applied between the welding wire 11 and the cutting material 13.
0, and also connected to one input terminal of a comparator 52 of a trigger circuit 51 that controls the memory 50's operation. The other input terminal of the comparator 52 is connected to a reference voltage setter 53 that outputs a reference voltage corresponding to a value between the short circuit voltage and the arc voltage. The output terminal of the comparator 52 is connected to the above-mentioned unit 50, and when the detected voltage becomes lower than the reference voltage and the output of the comparator 52 becomes 1, the memory 50 is activated and the memory 5o is activated. Voltage detector 20
The lowest value of the terminal voltage detected is stored.

The output terminal of the memory device 50 is connected to one input terminal of a subtracter 54, and the other input terminal of this subtractor 54 is connected to the output terminal of the voltage detector 2o.
Difference △V between the lowest value stored in 0 and the terminal voltage (Figure 3)
Calculate.

The output terminal of the gray reducer 54 is connected to one input terminal of a comparator 55, and the other input terminal of the comparator 55 is connected to D? A
The output terminal is connected to a level setter 56, and the output terminal is connected to an analog switch 57. The input terminal of the analog switch is connected to a short-circuit late current setting device 58, and the output terminal is connected to an error amplifier 6o for short-circuit current reduction.

In the configuration shown in ``-'', the voltage decreases when a short circuit occurs, and there is a clear voltage difference from when an arc occurs. When the output of the voltage detector 2o becomes smaller than the output of the base thread voltage setter 53, the trigger circuit 51 instructs the storage device 50 to start storing 1, [:. This 1.1-1m'd7H50 records the lowest value of the voltage detector 20 and the lowest voltage of the Zunawa output terminals -100 and 101 after the start of storage. and 71
．． [The device 54 outputs 6 of the voltage detector 20 and the output of the voltage detector 50, and the output device 55 sets the output of the subtractor 54 to the level setting device 56. analog switch 57 when it becomes larger than the installation rL.
/'\ is turned ON to set the current after short circuit 'A:'f, the signal of 58 is input to the error amplifier 60, and the signal of 58 is input to the error amplifier 60,
8 signals and currents, i', I', t W 21's signal bias;' (1 is amplified by the error amplifier 60,
The output current of the power supply is controlled to be the current value instructed by the short-circuit late current setting device 58. Here, although not shown, the IIS with the analog switch 53 turned OFF has a current setting value larger than the current value instructed by the short-circuit current setting device 64, or a current limit value, Lli!
The error amplifier 60 is configured such that a signal with no L is inputted to the error amplifier 60.

Diodes 65, 66, and 68 are so-called diode OR
The pulse width setting unit 67 sets a pulse width that satisfies the condition of any one of the error amplifiers 60, 61, and 63.

The operation of this power supply will be explained below. Short circuit late current setting device 5
8 generates a signal corresponding to an output current of 200A, the short circuit current setting device 64 generates a signal corresponding to an output current of 400A, and the voltage setting device 62 generates a signal corresponding to an output type IE23V. Wire 11 has an average current of 21O
When the current is being fed at a speed corresponding to A, the current is approximately 23V-180A during arcing, and at this time the analog switch 57 is OFF and there is no limit to the current.

Therefore, the error amplifiers 60, 61, and 63 respectively instruct the power supply to output ωA, 400A, and 23V, but the diode OR circuit satisfies the voltage of 23V, so the output voltage of the power supply becomes 23V.

Next, when the output of the comparator 55 has not yet turned on the analog switch 57 after a short circuit between the welding wire 11 and the workpiece 13 has occurred, the error amplifiers 60, 61, and 63 are connected to the pulse width setting device, respectively. 67VC'AJ,cy)A,
The I'M output is 400A and 23V. The power supply device i is trying to output 23 V, but due to a short circuit, the load impedance decreases, so the load current increases, and the output terminal voltage does not reach 23 V, and the load receives a current of 400 A. flows. At this time, the error amplifier 6
Short circuit current setting device 6 for the value indicated by 0.61.63
Since the 400A set in 4 is satisfied, the power supply outputs 4.0 OA regardless of the voltage. The power supply voltage at the short-circuit amount is applied to the comparator 52 via the voltage detector 20 and compared with the setter FE by the reference voltage setter 53, and when the power supply voltage is lower than the set value, the comparator 52 disappears:
A command is given to the memory 50 to start recording the lowest voltage. When the detected voltage obtained from the voltage detector 2o becomes the lowest, the lowest one voltage VL is stored in the memory 50.

Next, the short circuit time has elapsed and the lowest value V stored in the memory 5o
The difference between 1 and the output VM of the voltage detector 20 is calculated by the subtracter 54, and when the difference becomes larger than the setting value of the level setter 56, the comparator 55 turns on the analog switch 57. The signal from the short-circuit late current setting device 58 is then input to the error amplifier 60 via the analog switch 57.

The error amplifiers 60, 61, and 63 are 200A and 4.
The power supply is instructed to output 0OA, 23y, but the output of the error amplifier 60 is given priority and the output of the power supply is determined with a target of 20OA. Power supply output current U240
It drops from 0A to 200A.

In this way, since the open current in the subsequent arc generation 1 from the latter stage of the short circuit is as low as 20 OA, the occurrence of spatter is reduced.

When an arc occurs in the next arc generation period, the trigger circuit 51 instructs to erase the memory in the memory 50, and as a result, the analog switch 57 is turned OFF and the operation returns to the above-described operation during arc generation.

As mentioned above, in order to ensure a reduction in spatter, it is effective to start storing data in the memory device 50 after the time tQ shown in FIG. However, this purpose can be achieved by configuring the contents of the trigger circuit 51 as shown in FIG.

In FIG. 6, a comparison is made in which a signal is generated when the signal of the electric current detection delay 20 is smaller than the signal of the basic voltage generator 71, which generates a voltage corresponding to the voltage between the ground voltage and the arc voltage. When the signal from the current detector 72 and the current detector 21 becomes equal to or slightly larger than the signal from the reference voltage setter 73, which generates a signal corresponding to a current slightly smaller than the short-circuit current value, the signal is output. Generated comparator 74 and comparator 72
．． A trigger circuit 51 comprising a logic circuit 75 instructs the memory 50 to start storing when both signals from the comparator 74 output signals and to erase the memory when the signal output from the comparator 72 disappears. Memory starts when a short circuit occurs and the current reaches the short circuit current value, and the memory can be erased as soon as an arc occurs.

Further, in order to ensure a reduction in spatter even when the short circuit current is made variable, the level setter 56 may be configured as shown at 80 in FIG. 7.

That is, after the output of the current detector 21 is waveform-shaped by the filter circuit 81, it is multiplied by a constant k, which is a multiplier 82, and input to the comparator 55. Here, the multiplier 82 includes an operational amplifier Q and a resistor RI.
It is sufficient to configure the structure as shown in FIG. 7 with O and R11.''--The constant described is R11/R1,0. In this way, the level setter 80 inputs k·I(-Δ■) to the comparator 55, so that spacks can be reliably reduced even in special applications where the short circuit current is varied as described above. Here, the filter circuit 81 is not required if the current waveform is smooth.

As described in detail below, according to the present invention, in a power supply device for short-circuit transition welding that performs welding while repeatedly generating an arc and shorting, the lowest voltage at the time of a short-circuit between the welding wire and the base metal is set for each short-circuit. Each cycle is stored in a memory, and when the terminal voltage of the power supply device becomes higher than the minimum voltage stored above by a predetermined value, the short circuit current is suppressed and arcing occurs, which occurs at the end of the short circuit. It is now possible to effectively prevent spatter, thereby improving the wire welding effect and eliminating spatter that forms on the base metal. -1- The number of welding interruptions required to remove spatter adhering to the nozzle is greatly reduced, making continuous welding possible for a long time. The effect of being able to perform continuous welding for long periods of time is not only that the ratio of arc generation time to working hours increases, but also that the number of times spatter adhering to the nozzle can be removed is reduced due to robotization of welding work, which is currently being rapidly expanded in application. Since this method greatly reduces the amount of energy generated, it has the effect of being able to operate almost unmanned, making it very effective industrially.

[Brief explanation of the drawing]

Figure 1 shows the process of short-circuit transfer welding, and (a) shows the droplet transfer process. , (1)) shows the voltage waveform, and (C) d shows the current waveform. Figure 2 is a circuit diagram showing an example of a short-circuit transition welding device, Figure 3 is a method for detecting the point at which the current is lowered before arc regeneration, and Figure 4 is a schematic diagram of an inverter-type welding power source. FIG. 5 is a block diagram showing an embodiment of the present invention.
Figure 6 is a circuit diagram showing another modification of the trigger circuit used in the embodiment of Figure 5, and Figure 7 is a detailed diagram of the level setter used in the embodiment of Figure 5. This is a circuit diagram. 6... Power supply, 7... Current detector, 8... Voltage detector, 9... Power supply cable, 10... Contact tip, 11... Welding wire, 14... Earth cable, 19...Reactor, 20...Voltage detector, 21
...Current detector, 30-33...Transistor, 4
2...Transformer, 43-46...Diode, 50
... Memory device, 51 ... Trigger circuit, 52 ... Comparator, 53 ... Reference electronic setter, 54 ... Subtractor, 5
5... Comparator, 56... Level setter, 57...
Analog switch, 58...Short circuit late current setting device, 6
0...error amplification? Doo, 61...Error amplifier, 62.
...Voltage setting device, 63...Error amplifier, 64...Current setting device, 65.66.68...Diode, 67 width Patent applicant Murase Kogyo Co., Ltd. and one other attorney attorney Aoyama Hajime 2 people outside

Claims (1)

[Claims] (1) A welding power supply device used for short-circuit transition welding in which short circuits and arcs occur alternately, including a voltage detector that detects the output voltage of the power supply device and a voltage detector that detects the lowest value of the output voltage in the event of a short circuit. A memory device for storing data, a trigger circuit for instructing the memory device to start and erase data, a level setter, an output voltage detected by the voltage detector, and a minimum of the output voltages stored in the memory device. The present invention includes a comparator that outputs a signal when the difference between the output signal and the output signal of the level setting device is greater than the output signal of the level setting device, a short-circuit late current setting device, and a welding power output section, A power supply device for welding, characterized in that a power output section outputs a current instructed by an early short circuit/later current setting device in response to the current setting device. (2) Claims characterized in that the trigger circuit includes a second comparator that determines whether a short circuit or an arc occurs, and instructs the memory device to start storing when a short circuit occurs and erase the memory when an arc occurs. The welding power supply device according to item 1. A second comparator that determines whether the f31 to IJ circuit is short-circuited or an arc has occurred, a third comparator that determines whether the return current has reached the setting current, and a second comparator that determines whether the return current has reached the Comparator and third
It consists of a logic circuit that receives the output of the comparator and determines the instructions to the memory, which starts the memory when a short circuit occurs and the short circuit current reaches the set value, and erases the memory when an arc occurs. The welding power supply device according to claim 1, wherein the welding power supply device is configured to provide instructions. (4) The level setter is composed of a current detector that detects the current output from the power supply device and a multiplier, and the value obtained by multiplying the signal of the current detector by a certain constant is used as the output signal of the level setter. A welding power supply device according to claim 1, characterized in that: (5) The power output section consists of a primary rectifier, an inverter, a transformer, and a secondary rectifier, and the inverter frequency is 5
Claim 1 characterized in that:
” [The device described in paragraphs 1 to 4.