JP3833137B2 - Output control method for welding power supply - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an output control method for a welding power source device that can set a proper inductance value and a proper external characteristic inclination to desired values in the welding power source device.
[0002]
[Prior art]
FIG. 1 is a configuration diagram of a consumable electrode gas shield arc welding apparatus. The welding power supply device PS is output-controlled so that the external characteristic becomes a constant voltage characteristic, and outputs a welding voltage v and a welding current i suitable for welding. The welding wire 1 is fed through the welding torch 4 by the rotation of the feeding roll 5 directly connected to the wire feeding motor WM, and is fed through the feeding tip 4a and arcs with the base material 2. 3 occurs.
[0003]
FIG. 2 is an equivalent circuit diagram of the above-described welding power source apparatus PS. As described above, since the welding power source device has a constant voltage characteristic, it can be expressed as a constant voltage source E [V]. Further, the internal resistance value of the welding power source device is Ri [Ω], and the internal inductance value is Li [H]. This internal resistance value Ri is a resistance value of a wiring cable or the like inside the welding power source apparatus, and the value is usually a small value of about 0.02 to 0.05 [Ω]. On the other hand, the above-mentioned internal inductance value Li is an inductance value of the reactor for optimizing the amount of change in the welding current that changes in accordance with the change in the welding load to obtain a stable welding state. This internal inductance value Li is set to an appropriate value within a range of about 100 to 500 [μH] according to welding conditions such as the material of the welding wire, the feeding speed, and the welding method. For example, in carbon dioxide arc welding of steel, Li = 120 [μH] is an appropriate value in the short-circuit transition region when the feed rate is low and the current is low, and the globule transition region when the feed rate is high and the current is high Then, Li = 240 [μH] is an appropriate value. In addition, in MIG welding of aluminum, Li = 200 [μH] is an appropriate value in the short-circuit transition region when the feeding speed is low and the current is low, and globules or sprays when the feeding speed is high and the current is high In the transition region, Li = 300 [μH] is an appropriate value.
[0004]
FIG. 3 is a voltage / current waveform diagram of the short-circuit transition region described above, where FIG. 3 (A) shows the time change of the welding voltage v, and FIG. 3 (B) shows the time change of the welding current i. During the short-circuit period Ts from time t1 to t2, the welding voltage v becomes a short-circuit voltage vs of about several [V] as shown in FIG. 9A, and the short-circuit current is is shown in FIG. It rises at a slope determined by the internal inductance value described above. Subsequently, during the arc period Ta from time t2 to t3, the arc voltage va becomes a voltage value corresponding to the arc length as shown in FIG. 5A, and the arc current ia as shown in FIG. Falls or changes at a slope determined by the above-described internal inductance value. If the above-described change in the short-circuit current is and the change in the arc current ia when the welding load varies due to the variation in the arc length is appropriate, a stable welding state is obtained. Therefore, in order to obtain a stable welding state, it is necessary to set the above-described internal inductance value to an appropriate value.
[0005]
4A and 4B are voltage / current waveform diagrams in the above-described globule transition region, where FIG. 4A shows the time change of the welding voltage v, and FIG. 4B shows the time change of the welding current i. When the droplet moves at time t1, the arc length suddenly increases and the welding load fluctuates, so that the welding voltage v shown in FIG. 5A and the welding current i shown in FIG. If these voltage / current changes are appropriate, the welding state becomes stable. Therefore, it is necessary to set the above-described internal inductance value that determines the voltage / current change to an appropriate value.
[0006]
As described above, in the welding power supply device for consumable electrode gas shielded arc welding, the internal inductance value is set to an appropriate value in order to obtain a stable welding state by optimizing changes in the welding voltage and welding current with respect to fluctuations in the welding load. Must be set. However, a reactor having an inductance value of several hundreds [μH] through which several hundreds [A] is energized has a very large volume, a very heavy weight, and a high cost. Furthermore, as described above, the inductance value of the reactor needs to be set to an appropriate value in a wide range of 100 to 500 [μH] according to various welding conditions, but is formed by winding a cable around an iron core. The inductance value cannot be changed to an arbitrary value in the reactor. Therefore, in general, the inductance value is set assuming standard welding conditions. For this reason, there is a problem that the inductance value is not the most stable welding state under various welding conditions.
[0007]
In order to solve the above-described problems, so-called electronic reactor control in which an electronic circuit performs an action equivalent to a reactor has been proposed. Hereinafter, this control method will be described.
[0008]
In the equivalent circuit described above with reference to FIG.
E = Ri · i + Li · di / dt + v (1)
Here, E [V] is an output voltage, Ri [Ω] is an internal resistance value, Li [H] is an internal inductance value, i [A] is a welding current, and v [V] is a welding voltage.
As described above, since the internal resistance value Ri is usually a small value and can be omitted, the above equation (1) can be arranged as the following equation.
E-Li · di / dt = v (2)
An equivalent circuit corresponding to the above equation is shown in FIG.
[0009]
Here, when the control output voltage is defined as Ec = E−Li · di / dt, Ec = v, and the equivalent circuit is as shown in FIG. Therefore, in order to perform an operation equivalent to the internal inductance value Li in FIG. 5A, the control output voltage Ec may be controlled to be E-Li · di / dt. That is, the basic formula of electronic reactor control is the following formula.
Ecr = Er−Lr · di / dt (3)
However, Ecr [V] is the control output voltage setting value, Er [V] is the output voltage setting value, Lr [H] is the inductance setting value that is the same value as the internal inductance value Li [H], and di / dt is the welding current i. Is the differential value of.
In the electronic reactor control, the output voltage set value Er and the inductance set value Lr are set in advance, the differential value of the welding current during welding is calculated, the control output voltage set value Ecr is calculated by the above equation (3), and the welding power source Control is performed so that the output voltage of the apparatus is substantially equal to the control output voltage set value Ecr. By controlling the output voltage as described above, as shown in FIG. 5 (B), an action equivalent to the internal inductance value Li of the reactor shown in FIG. 5 (A) can be obtained without inserting an actual reactor into the circuit. Can be made. An electronic reactor having an optimum inductance value can be created simply by setting the inductance setting value Lr in the above equation (3) to a desired value according to various welding conditions.
[0010]
Incidentally, the control output voltage Ec shown in FIG. 5B is generally formed by an inverter-controlled welding power supply device or the like. Therefore, a reactor having a small inductance value of about several tens [μH] for smoothing the pulse-like output on the secondary side of the inverter transformer is generally provided inside the welding power source apparatus. Furthermore, an external inductance value by a welding cable connecting the output terminal of the welding power supply device and the welding torch or the base material is also inserted into the circuit. When these internal and external inductance values are expressed as Lio [H], an equivalent circuit is shown in FIG. In the same figure, when the appropriate inductance value corresponding to the welding conditions is expressed as Lm [H], the above equation (3) becomes the following equation.
Ecr = Er− (Lm−Lioo) · di / dt (4)
That is, the inductance setting value Lr = Lm−Lio may be set.
[0011]
FIG. 6 is a block diagram of the above-described electronic reactor control welding power supply apparatus. Hereinafter, each circuit block will be described with reference to FIG.
The output control circuit INV receives a commercial power supply such as a three-phase 200 V input, performs output control such as inverter control and chopper control in accordance with a voltage error amplification signal Amp described later, and outputs an output voltage E. The direct current reactor DCL is a reactor corresponding to the aforementioned internal / external inductance value Lio, and smoothes the output. The output voltage detection circuit ED detects the output voltage E and outputs an output voltage detection signal Ed. The welding current detection circuit ID detects the welding current i and outputs a welding current detection signal id.
[0012]
The electronic reactor control circuit ERC has the above welding current detection signal id as an input,
Lr · di / dt is calculated. Here, the inductance setting value Lr is set to Lr = Lm−Lio by the appropriate inductance value Lm as described above. The output voltage setting circuit ER outputs an output voltage setting signal Er having a desired value. The subtraction circuit SUB performs a subtraction of Er−Lr · di / dt and outputs a control output voltage setting signal Ecr. Therefore, the above equation (3) is calculated by the electronic reactor control circuit ERC and the subtraction circuit SUB. The voltage error amplification circuit AMP amplifies an error between the control output voltage setting signal Ecr and the output voltage detection signal Ed and outputs a voltage error amplification signal Amp. With the above operation, a welding power source apparatus corresponding to the above-described equivalent circuit of FIG.
[0013]
[Problems to be solved by the invention]
In the conventional electronic reactor control, the output voltage is controlled based on the above-described equation (3) Ecr = Er−Lr · di / dt. And it sets to inductance setting value Lr = Lm-Lio by the suitable inductance value Lm and internal / external inductance value Lio which are decided according to welding conditions. However, since the internal inductance value of the internal reactor varies depending on the type of the welding power source device, it is necessary to finely adjust the inductance setting value Lr for each type of the welding power source device even if the appropriate inductance value Lm is the same value. It takes time to make fine adjustments. Furthermore, since the external inductance value due to the welding cable varies greatly depending on the length and the routing of the welding cable, it is necessary to finely adjust the inductance setting value Lr according to the external inductance value in order to always maintain the appropriate inductance value Lm. is there. If this is neglected, it will deviate from the appropriate inductance value, and as a result, the welding state may become unstable.
[0014]
Therefore, the present invention provides an output control method for a welding power source apparatus that can form an electronic reactor that always maintains an appropriate inductance value Lm even when the internal / external inductance value Lio changes.
[0015]
[Means for Solving the Problems]
As shown in FIG.
The welding current i is controlled by calculating the amount of change in the welding current i according to a value obtained by multiplying the difference between the output voltage set value Er of the welding power supply device and the detected value vd of the welding voltage by a predetermined coefficient. This is an output control method for the welding power source apparatus.
[0016]
As shown in FIG.
An output voltage setting value Er [V] for setting the output voltage E of the welding power source device and an inductance setting value Lr [H] for setting the appropriate inductance value Lm of the welding power source device are set in advance.
The welding voltage v and welding current i during welding are detected, and the current setting change amount ΔIr = (Er−vd) / Lr is calculated using the welding voltage detection value vd [V] as an input, and this current setting change amount ΔIr is calculated. A welding power control set value Irc is integrated to calculate the welding current control set value Irc, and the output is controlled so that the welding current detection value id is substantially equal to the welding current control set value Irc. is there.
[0017]
As shown in FIGS.
An output voltage setting value Er [V] for setting the output voltage E of the welding power source device, an inductance setting value Lr [H] for setting the appropriate inductance value Lm of the welding power source device, and a slope S of the external characteristic of the welding power source device are set. The external characteristic inclination setting value Sr [V / A] is set in advance,
The welding voltage v and welding current i during welding are detected, and the current setting change amount ΔIr = (Er−vd−Sr · id) with the welding voltage detection value vd [V] and the welding current detection value id [A] as inputs. ) / Lr is calculated, the current setting change amount ΔIr is integrated to calculate the welding current control set value Irc, and the output is controlled so that the welding current detection value id is substantially equal to the welding current control set value Irc. It is the output control method of the welding power supply device characterized by doing.
[0018]
As shown in FIGS.
In the output control method of the welding power source apparatus used for the consumable electrode gas shield arc welding that repeats the short circuit period and the arc period between the welding wire and the base material,
The second or third aspect of the invention is characterized in that the welding current control set value Irc is replaced with a predetermined short-circuit initial current set value Isi only during a predetermined short-circuit initial time Tsi after occurrence of a short circuit. It is an output control method of the described welding power supply device.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[Embodiment 1]
FIG. 7A corresponds to the above-described FIG. 5A and is an equivalent circuit diagram of a welding power supply device having a constant voltage characteristic having an appropriate inductance value Lm. In the same figure, the following formula is established in the same manner as the above-described formula (2).
E = Lm · di / dt + v
However, E [V] is an output voltage, Lm [H] is an appropriate inductance value, i [A] is a welding current, and v [V] is a welding voltage.
When the above equation is arranged, the following equation is obtained.
di / dt = (E−v) / Lm
Integrating both sides gives the following formula.
i = ∫ ((E−v) / Lm) · dt
Here, when the welding current i is replaced with the welding current control set value Irc, the output voltage E is replaced with the output voltage set value Er, and the appropriate inductance value Lm is replaced with the inductance set value Lr, the following equation is obtained.
Irc = ∫ ((Er−v) / Lr) · dt (5)
An equivalent circuit corresponding to the above equation is shown in FIG. In the figure, the welding voltage v is detected and the welding current control set value Irc corresponding to the welding current i of the constant current source CC is controlled to be the calculated value of (5) above. Thereby, the change of the welding current i with respect to the fluctuation of the welding load becomes the same as that in FIG. Therefore, the above equation (5) is the basic equation for control of the present invention.
[0020]
FIG. 7C shows an equivalent circuit when the internal / external inductance value is Lio as described above with reference to FIG. In the same figure, the change of the welding current i with respect to the fluctuation of the welding load is the same with Lr = Lm in the above formula (5). In other words, even if the internal / external inductance value Lio changes, the control method of the present invention is not affected. Therefore, even if the internal inductance value changes depending on the type of the welding power source device and the external inductance value changes depending on the length and the length of the welding cable, the inductance setting value Lr in the above equation (5) is always the appropriate inductance. The value Lm may be set as it is.
[0021]
As described above, the first embodiment of the present invention is a value obtained by multiplying the difference (Er−vd) between the output voltage set value Er of the welding power supply apparatus and the detected value vd of the welding voltage by a predetermined coefficient 1 / Lr. This is an output control method of the welding power source apparatus that calculates the amount of change Δi of the welding current i in accordance with and controls the welding current i.
[0022]
[Embodiment 2]
In the second embodiment of the present invention, an output voltage setting value Er [V] for setting the output voltage of the welding power supply device and an inductance setting value Lr [H] for setting the appropriate inductance value Lm of the welding power supply device are set in advance. The welding voltage v and welding current i during welding are detected, and the current setting change amount ΔIr = (Er−vd) / Lr is calculated based on the above equation (5) with the welding voltage detection value vd [V] as an input. Then, the welding current control set value Irc is calculated by integrating the current setting change amount ΔIr, and the output is controlled so that the welding current detection value id is substantially equal to the welding current control set value Irc.
[0023]
FIG. 8 is a block diagram of the welding power source apparatus of the second embodiment. Hereinafter, each circuit block will be described with reference to FIG.
The output control circuit INV receives a commercial power source such as a three-phase 200 V input, performs output control such as inverter control and chopper control in accordance with a current error amplification signal Api described later, and outputs a welding current i. The direct current reactor DCL is a reactor corresponding to the internal / external inductance value Lio, and smoothes the output. The welding voltage detection circuit VD detects the welding voltage v and outputs a welding voltage detection signal vd. The welding current detection circuit ID detects the welding current i and outputs a welding current detection signal id.
[0024]
The output voltage setting circuit ER outputs an output voltage setting signal Er having a desired value. The inductance setting circuit LR outputs an inductance setting signal Lr corresponding to the appropriate inductance value Lm. The current setting change amount calculation circuit DIR receives the welding voltage detection signal vd, the output voltage setting signal Er, and the inductance setting signal Lr, calculates (Er−vd) / Lr, and generates a current setting change amount signal ΔIr. Output. The integration circuit IIR integrates the current setting change amount signal ΔIr and outputs a welding current control setting signal Irc. The current error amplification circuit API amplifies an error between the welding current control setting signal Irc and the welding current detection signal id and outputs a current error amplification signal Api. With the above operation, the welding power source apparatus forms the constant current source CC described above with reference to FIGS.
[0025]
[Embodiment 3]
The third embodiment of the present invention is an output control method capable of setting the slope S [V / A] of the external characteristic of the welding power source device to a desired value in the second embodiment described above. That is, in the third embodiment of the present invention, the output voltage set value Er [V], the inductance set value Lr [H], and the appropriate external characteristic slope set value Sr [V / A] are set in advance, and the welding voltage during welding is set. v and the welding current i are detected, and the welding voltage detection value vd [V] and the welding current detection value id [A] are input to calculate a current setting change amount ΔIr = (Er−vd−Sr · id) / Lr. The welding current control set value Irc is calculated by integrating the current setting change amount ΔIr, and the output is controlled so that the welding current detection value id becomes substantially equal to the welding current control set value Irc.
[0026]
FIG. 9A corresponds to FIG. 2 described above, and is an equivalent circuit diagram of a welding power supply device having a constant voltage characteristic having an appropriate inductance value Lm and an appropriate resistance value Rm. In the same figure, the following equation is established in the same manner as the above-described equation (1).
E = Rm · i + Lm · di / dt + v (6)
However, E [V] is an output voltage, Rm [Ω] is an appropriate resistance value, Lm [H] is an appropriate inductance value, i [A] is a welding current, and v [V] is a welding voltage.
In the above equation, the relationship between the welding voltage v and the welding current i when the current change di / dt = 0 is the external characteristic. Substituting di / dt = 0 into the above equation yields the following equation.
v = E−Rm · i
The above equation is represented in a graph as shown in FIG. In the figure, the horizontal axis represents the welding current i, and the vertical axis represents the welding voltage v. Since Rm ≧ 0, the graph is a straight line that descends to the right, and the slope of the straight line is Sm [V / A] = Rm [Ω]. Therefore, in the above equation (6), when Rm = Sm is substituted, the following equation is obtained.
E = Sm · i + Lm · di / dt + v
When the above equation is arranged, the following equation is obtained.
di / dt = (E−v−Sm · i) / Lm
Integrating both sides gives the following formula.
i = ∫ ((Ev-Sm · i) / Lm) · dt
Here, the welding current i is set to the welding current control set value Irc, the output voltage E is set to the output voltage set value Er, the appropriate external characteristic slope Sm is set to the external characteristic slope set value Sr, and the appropriate inductance value Lm is set to the inductance set value Lr. When each is replaced, the following formula is obtained.
Irc = ∫ ((Er−v−Sr · i) / Lr) · dt (7)
An equivalent circuit corresponding to the above equation is shown in FIG. In the figure, the welding voltage v and the welding current i are detected, and the welding current control set value Irc corresponding to the welding current i of the constant current source CC is controlled to be the calculated value of the above equation (7). Thereby, the change of the welding current i with respect to the fluctuation of the welding load becomes the same as that in FIG. Therefore, the above equation (7) is the basic equation for the control of the third embodiment.
[0027]
FIG. 9C is an equivalent circuit in the case where the internal / external inductance value is Rio and the internal / external resistance value obtained by combining the internal resistance and the external resistance by the welding cable is Rio as described above with reference to FIG. Indicates. In the same figure, the change of the welding current i with respect to the fluctuation of the welding load is the same with Lr = Lm and Sr = Sm in the above equation (7). In other words, even if the internal / external inductance value Lio and the internal / external resistance value Rio change, the control method of the third embodiment is not affected. Therefore, even if the internal inductance value and the internal resistance value change depending on the type of the welding power source device, and the external inductance value and the external resistance value change due to the length and routing of the welding cable, The inductance setting value Lr and the external characteristic inclination setting value Sr may always be set to the appropriate inductance value Lm and the appropriate external characteristic inclination Sm.
[0028]
In the third embodiment described above, the reason for setting the appropriate external characteristic inclination setting value Sm in addition to the appropriate inductance value Lm is as follows. That is, the appropriate external characteristic gradient Sm is about 0.02 to 0.05 [V / A] in carbon dioxide arc welding or MAG welding of steel, and 0.08 to 0.15 [V / A] in aluminum MIG welding. A]. Therefore, in order to obtain a stable welding state depending on the material of the welding wire, the welding method, etc., it is necessary to set the external characteristic inclination to an appropriate value.
[0029]
FIG. 11 is a block diagram of the welding power supply apparatus of the third embodiment described above. In the figure, the same circuit blocks as those in FIG. 8 described above are denoted by the same reference numerals, and description thereof is omitted. Hereinafter, a circuit block indicated by a dotted line different from FIG. 8 will be described with reference to FIG.
[0030]
The external characteristic inclination setting circuit SR outputs an external characteristic inclination setting signal Sr having a desired value. The second current setting change amount calculation circuit DIR2 receives the welding voltage detection signal vd, the welding current detection signal id, the output voltage setting signal Er, the inductance setting signal Lr, and the above-described external characteristic inclination setting signal Sr as (Er− vd−Sr · id) / Lr is calculated and a current setting change amount signal ΔIr is output.
[0031]
[Embodiment 4]
Embodiment 4 of the present invention relates to an output control method for a welding power source apparatus used for consumable electrode gas shield arc welding in which a short-circuit period and an arc period are repeated between a welding wire and a base material. The welding current control set value Irc described in 3 is replaced with a predetermined short-circuit initial current set value Isi only during a predetermined short-circuit initial time Tsi after the occurrence of a short circuit. is there. The reason why the welding current value during the short-circuit initial time Tsi is set to a small current value is as follows. That is, if the welding current value increases immediately after the occurrence of a short circuit, the short circuit state is released in a short time, and a micro short circuit that does not involve droplet transfer is likely to occur. As a result, many spatters occur and the bead appearance also deteriorates. If the welding current value immediately after the short-circuit is reduced, the occurrence of minute short-circuits can be reduced, resulting in less spatter and better bead appearance. Hereinafter, description will be given with reference to the drawings.
[0032]
FIG. 12 is a voltage / current waveform diagram of consumable electrode gas shielded arc welding accompanied by a short circuit. FIG. 12 (A) shows the time change of the welding voltage v, and FIG. 12 (B) shows the time change of the welding current i. Show. When a short circuit occurs at time t1, the welding voltage v becomes a low value of about several [V] as shown in FIG. Therefore, in Formula (5) of Embodiment 2 or Formula (7) of Embodiment 3 described above, Er−v> 0, so the welding current control set value Irc is as shown in FIG. To increase. As described above, if the welding current i increases immediately after the short circuit, a lot of micro short circuits occur, resulting in poor bead appearance. In order to suppress this, as shown in FIG. 4B, during a predetermined short-circuit initial time Tsi after the occurrence of a short-circuit, a short-circuit initial current Isi having a predetermined small current value is applied.
[0033]
FIG. 13 is a block diagram of the welding power supply apparatus of the fourth embodiment described above. This figure is obtained by adding short-circuit initial current control to the welding power source apparatus of the third embodiment described above with reference to FIG. In the figure, the same circuit blocks as those in FIG. 11 described above are denoted by the same reference numerals, and description thereof is omitted. Hereinafter, a circuit block indicated by a dotted line different from FIG. 11 will be described with reference to FIG.
[0034]
The short circuit determination circuit SD determines the short circuit state with the welding voltage v as an input, and outputs a short circuit determination signal Sd that becomes a high level. The short-circuit initial time timer circuit TSI outputs a short-circuit initial time signal Tsi that becomes High level for a predetermined time from the time when the short-circuit determination signal Sd changes to High level (short circuit). The short-circuit initial current setting circuit ISI outputs a predetermined short-circuit initial current setting signal Isi. The current setting switching circuit ISW outputs the short-circuit initial current setting signal Isi as the current setting switching signal Isw when the short-circuit initial time signal Tsi is High level, and the welding current control setting signal Irc when the Low-level initial time signal Tsi is Low level. Output as the switching signal Isw. The welding current i is controlled according to the current setting switching signal Isw.
[0035]
Although the case where the short-circuit initial current control is added to the third embodiment has been described above, the same applies to the case where it is added to the welding power source apparatus of the second embodiment described above with reference to FIG.
[0036]
【The invention's effect】
According to the output control method of the welding power source apparatus of the present invention, the appropriate inductance value Lm can be electronically formed without being affected by the internal / external inductance value Lio, so that the welding voltage and A change in the welding current becomes appropriate, and a stable welding state can be obtained.
Furthermore, in the third embodiment of the present invention, in addition to the above effects, the external characteristic inclination of the welding power source device can be set to an appropriate value according to various welding conditions, so that the welding state is further stabilized.
Furthermore, in Embodiment 4 of the present invention, an increase in welding current immediately after the occurrence of a short circuit can be suppressed, so that the occurrence of micro short circuits is reduced and the welding quality is improved.
[Brief description of the drawings]
FIG. 1 is a block diagram of a conventional consumable electrode gas shield arc welding apparatus.
FIG. 2 is an equivalent circuit diagram of FIG.
3 is a voltage / current waveform diagram of short-circuit transfer welding in the prior art.
FIG. 4 is a voltage / current waveform diagram of globule transition welding in the prior art.
FIG. 5 is an equivalent circuit diagram for explaining prior art electronic reactor control.
FIG. 6 is a block diagram of a conventional electronic reactor control welding power source device.
FIG. 7 is an equivalent circuit diagram for explaining the first embodiment of the present invention;
FIG. 8 is a block diagram of a welding power source apparatus according to a second embodiment of the present invention.
FIG. 9 is an equivalent circuit diagram for explaining the third embodiment of the present invention;
FIG. 10 is an external characteristic diagram formed by the third embodiment of the present invention.
FIG. 11 is a block diagram of a welding power supply apparatus according to a third embodiment of the present invention.
FIG. 12 is a voltage / current waveform diagram for explaining the fourth embodiment of the present invention;
FIG. 13 is a block diagram of a welding power source apparatus according to a fourth embodiment of the present invention.
[Explanation of symbols]
1 Welding wire
2 Base material
3 Arc
4 Welding torch
4a Feeding chip
AMP voltage error amplifier circuit
Amp Voltage error amplification signal
API Current error amplifier circuit
Api Current error amplification signal
CC constant current source
DCL DC reactor
DIR Current setting change amount calculation circuit
DIR2 second current setting change amount calculation circuit
E Constant voltage source, output voltage
Ec Control output voltage
Ecr Control output voltage setting signal
ED output voltage detection circuit
Ed Output voltage detection signal
ER output voltage setting circuit
Er output voltage setting signal
ERC Electronic reactor control circuit
i Welding current
ia arc current
ID welding current detection circuit
id Welding current detection signal
IIR integration circuit
INV output control circuit
Irc welding current control setting signal
is short circuit current
ISI short-circuit initial current setting circuit
Isi short-circuit initial current (setting signal)
ISW current setting switching circuit
Isw current setting switching signal
Li Internal inductance value
Lio external inductance value
Lm Proper inductance value
LR inductance setting circuit
Lr Inductance setting signal
PS welding power supply
Ri internal resistance
Rio internal and external resistance
Rm proper resistance
SD short-circuit detection circuit
Sd Short circuit detection signal
SR external characteristic inclination setting circuit
Sr External characteristic tilt setting signal
SUB subtraction circuit
Ta arc period
Ts Short-circuit period
TSI short circuit initial time timer circuit
Tsi Short circuit initial time (signal)
v Welding voltage
va arc voltage
VD welding voltage detection circuit
vd Welding voltage detection signal
vs Short-circuit voltage
WM wire feed motor
ΔIr Current setting change (signal)

Claims (4)

A welding power source characterized in that a welding current is controlled by calculating a change amount of the welding current according to a value obtained by multiplying a difference between an output voltage setting value of the welding power source device and a detected value of the welding voltage by a predetermined coefficient. Device output control method. An output voltage setting value Er [V] for setting the output voltage of the welding power supply device and an inductance setting value Lr [H] for setting an appropriate inductance value of the welding power supply device are set in advance.
The welding voltage and welding current during welding are detected, the current setting change amount ΔIr = (Er−vd) / Lr is calculated using the welding voltage detection value vd [V] as an input, and the current setting change amount ΔIr is integrated. A welding power control set value is calculated, and the output is controlled so that the welding current detection value is substantially equal to the welding current control set value. An output voltage setting value Er [V] for setting the output voltage of the welding power source, an inductance setting value Lr [H] for setting an appropriate inductance value of the welding power source, and an external characteristic slope for setting the slope of the external characteristic of the welding power source Preset the set value Sr [V / A]
The welding voltage and welding current during welding are detected, and the welding voltage detection value vd [V] and the welding current detection value id [A] are used as inputs, and the current setting change amount ΔIr = (Er−vd−Sr · id) / Lr is calculated, the current setting change amount ΔIr is integrated to calculate a welding current control set value, and the output is controlled so that the welding current detection value is substantially equal to the welding current control set value. Output control method for welding power supply. In the output control method of the welding power source apparatus used for the consumable electrode gas shield arc welding that repeats the short circuit period and the arc period between the welding wire and the base material,
4. The welding according to claim 2, wherein the welding current control set value is replaced with a predetermined short-circuit initial current set value only during a predetermined short-circuit initial time after occurrence of a short-circuit. Power supply output control method.

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