JPH0985442A - Controller for setting droplet transfer state in arc welding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To establish an automatic welding program incorporated with an operation capable of selectively setting the proper welding conditions of a droplet transfer state specified for each joint. SOLUTION: A welding controller 4 is provided which gives a command to switch the current output mode of a welding power source 3 to a pulse mode and an ordinary mode; and the welding voltage imparted from the welding power source to a wire through the welding controller 4 is defined by a polynomial composed of a welding current term, tip-base material distance term and voltage constant term. At the time of initial setting, the polynomial is selected based on the input of specifications, thereby setting the welding conditions of pulse welding and of each droplet transfer state for spray transfer type and short circuiting transfer type, so that the correction of the welding voltage is performed on the basis of this polynomial during welding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a consumable electrode type arc welding using a shield gas, in which the droplet transfer mode can be designated for each welded joint of one workpiece. Regarding the setting management device.

[0002]

2. Description of the Related Art When welding one welded work piece, there are mixed joints that require bead appearance, joints that require strength, and joints that require both of these. Based on specifications, experience, etc., the person selects the droplet transfer mode, that is, the mode of the droplet separation phenomenon mainly due to electromagnetic force, according to these joints.

In particular, a short-circuit transfer type in which droplets having a large diameter are welded to the joint, a spray transfer type in which droplets are sprayed and welded, and one pulse / one melt controllable in synchronization with the droplet detachment operation of one drop Drop transfer type pulse welding and the like are used in welding sites of relatively small-scale workpieces in electric and machine manufacturing plants. By the way, it is said that the short-circuit transfer type is suitable for welding thin plates, the spray transfer type is suitable for welding thick plates, and the pulse welding is suitable for welded joints where importance is placed on appearance (reduction of spatter).

[0004]

When incorporating the above-mentioned operation of selecting a droplet transfer form into an automatic welding (semi-automatic welding) program, the droplet transfer form is specified by inputting specifications for each joint before the main welding, and during the main welding. It is conceivable to switch and set the welding conditions of current and voltage for the same droplet, but the welding conditions differ depending on the distance between the tip base metal (distance between the tip of the torch and the base metal) of each joint. The same welding condition cannot be set for two joints having different distances between the tip base metals even if they are in the transition form. Particularly, in the case of consumable electrode type arc welding, if the distance between the tip base materials is different, the arc length is changed and the welding current is also changed, so that the optimum voltage for maintaining the droplet transfer form also changes.

Therefore, in order to incorporate the droplet transfer mode selection operation into the automatic welding program, even if the same droplet transfer mode is selected, appropriate currents and voltages are applied to different tip base metal distances and optimum voltage changes for each joint. However, conventionally, there is no idea to set different welding conditions for each joint. Also, the change of droplet transfer form becomes spray transfer type as the current increases, but in the case of consumable electrode type arc welding, if the wire feed rate is constant and the distance between the tip base metal fluctuates during welding, Since the balance is lost and the current also fluctuates, it deviates from the optimum conditions of the spray transfer type. This also applies to the short-circuit transfer type.

Therefore, in order to incorporate the droplet transfer mode selection operation into the automatic welding program, it is necessary to properly set the welding conditions for the target droplet transfer mode and to maintain the droplet transfer mode during welding. It is necessary to control the welding conditions. The present invention
In view of the above conventional problems, a welding voltage is defined by a polynomial consisting of a welding current term, a distance between tip base metals and a voltage constant term, and the relationship between the current and the voltage according to the joint is defined by the polynomial. It is possible to freely set
The problem to be solved is to be able to control the optimum state of droplet transfer morphology with respect to variations in the distance between tip base materials during welding.

[0007]

The gist of the invention of claim 1 which has solved the above-mentioned problems is (a) a pulse mode for converting a welding current applied to a wire through a tip of a welding torch tip to a pulse mode and a direct current or an alternating current. The welding power source that can be switched to the normal mode, and (b) the welding power source is being welded to the welding power source in accordance with the droplet transfer mode specified by the operator at the time of inputting specifications to satisfy the welding quality items required for each joint. A welding controller that sends a mode switching signal for switching between a pulse mode and a normal mode, wherein the welding controller (c) gives a welding voltage applied to the wire from the welding power source to a welding current term and a tip base metal distance term. Is defined by a polynomial consisting of the voltage constant term and the voltage constant term, and at the time of initial setting, the above polynomial is determined based on the specification input. And there to the setting of the welding condition of each droplet transfer form of short circuit transfer type.

The gist of the invention of claim 2 is that, in the welding controller, the number of short-circuiting phenomena in which the tip of the wire comes into contact with the base metal during welding in the pulse welding setting is a preset number. Thus, the welding voltage is controlled by detecting the number of times of the short circuit phenomenon. The gist of the invention of claim 3 is that the welding controller substitutes the distance between the tip base metal obtained from the detected wire feeding speed and the detected welding current into the polynomial during the welding of the spray transfer type or the short circuit transfer type. It is to control the welding voltage.

The gist of the invention of claim 4 is that, even when the welding controller is set to (a) the spray transfer type, the number of short circuits in which the tip of the wire comes into contact with the base metal is a preset number. First, the number of times of the short circuit phenomenon is detected to control the welding voltage.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION A droplet transfer mode setting control device for arc welding according to the present invention will be described below in detail with reference to the drawings. As shown in FIG. 1, the equipment to which the droplet transfer mode setting control device for arc welding according to the present invention is applied includes an articulated robot 2 holding a welding torch (hereinafter abbreviated as torch) 1,
Based on the welding power output of the output terminals 3a, 3b, the welding power source 3 for supplying power to the tip 16 of the torch tip, and the welding power source 3 for outputting the current I and voltage V of the welding power output. A welding controller 4 that automatically sets command parameters P _I and P _V to be commanded and sends out the command signals i and v, and controls the articulated robot 2 based on teaching data TD including a command signal of welding speed. Robot controller 5, a wire feeder 8 for feeding the wire 7 as a consumable electrode filled in the drum 6 to the torch 1, and a jig 9 on which a welded article is placed.
It is composed of Here, the welding power source 3 can be switched between a pulse mode in which the welding current applied to the wire 7 via the tip 16 is pulsed and a normal mode in which the welding current is converted into a direct current or an alternating current.

It is assumed that the articulated robot 2 is provided with a waveform operation circuit for converting the teaching data TD into a drive signal format for activating the actual robot shaft based on the welding speed. The wire feeding device 8 assembled in the articulated robot 2 includes a bending straightener 11,
An encoder 12, a pair of feed rollers 13a and 13b sandwiching the wire 7, a rotary actuator 14 that drives the rollers 13a and 13b, and a torch cable 1a that guides the wire 7 to the torch 1, and the wire 7 is a nozzle in the torch 1. The tip 16 in the portion 15 is projected. Then, the rotary actuator 14 is controlled by the drive signal of the feed rate proportional to the magnitude (average value) of the welding current i from the robot controller 4 to feed out the wire 7, and the detection wire feed at that time is fed. The feed rate MR _a is sent from the encoder 12 to the welding controller 4.

The welding controller 4 automatically sets the welding conditions (current, voltage and speed) and automatically corrects the welding conditions with respect to disturbance, and its hardware is conceptually shown in FIG. , Joint shape, posture, welding method (spray transfer type and short circuit transfer type in the case of pulse welding and mag welding), leg length, tip base metal distance and plate thickness, or welding speed or fillet welding if necessary The basic specifications such as the welding cross-sectional area of (1) are set, for example, by the specification inputting means 41 which is input for every N joints in one product, and the welding conditions are calculated from the basic specifications input to the specification inputting means 41. Initial condition setting means 42 and the initial condition setting means 4
Calculation formula memory 4 storing each calculation formula used for calculation 2
3, the condition file 45 for storing the welding conditions set by the initial condition setting means 42, and the initial current command parameter P _I and the initial voltage command parameter P _V among the welding conditions set by the initial condition setting means 42. It is mainly composed of a condition automatic management correcting means 44 for setting a corrected current command parameter P _I ′ and a corrected voltage command parameter P _V ′ according to disturbance.

The correction current command parameter P _I ′ and the correction voltage command parameter P _V ′ in digital signal form are D
The / A converter converts the analog current command signal i and the voltage command signal v into the welding power source 3, and commands the current and voltage to be derived from the output terminals 3a and 3b. Further, the welding controller 4 sends to the welding power source 3 a mode switching signal 4a for switching between a pulse mode in which the welding current is pulsed and a normal mode in which the welding current is turned into a direct current or an alternating current.

Furthermore, the welding controller 4 detects the welding current I and the voltage output from the welding power source 3 by the welding current I.
_{The a} (average current of pulse current during pulse welding) and the detected welding voltage V _a are sampled. Here, the relationship between the initial current command parameter P _I and the modified current command parameter P _I ′ and the welding current I and the relationship between the initial voltage command parameter P _V and the modified voltage command parameter P _V ′ and the welding voltage V are as follows. The relationship is set such that the characteristics of the power supply 3 are corrected. That is, the current command parameters P _I and P _I ′ and the voltage command parameters P _V and P _V ′ are set so that the welding current and the welding voltage calculated in the welding controller 4 are output even if the welding power source changes. It is corrected every time.

On the other hand, the robot controller 5 is an electronic control device having a teaching data memory for each joint, and the robot controller 5 is used for actual welding.
Reads the data in each memory in order and reads the articulated robot 2
Each of the axes is driven and a condition calling signal 5a is sent to the welding controller 4 every time one memory is read out to access the condition file 45. As a result, the welding conditions (P _I , P _{I) for} each joint are synchronized with the teaching data TD.
_V , I, V and welding speed WS) are read.

The set of arithmetic expressions stored in the arithmetic expression memory 43 is obtained in advance by an experiment for each joint. Further, the arc ON / OFF signal, which means start and stop of main welding, is sent from the robot controller 5 to the welding controller 4
Sent to Next, how to set the droplet transfer form of the present invention and maintain and manage the droplet transfer form during welding according to the above configuration will be described with reference to FIGS.

The overall program flow is shown in FIGS. 3 and 4.
As shown in step S ₁ [Basic specifications input] and a preparation process consisting of steps S ₂ [Auto setting of the optimum welding condition] Step S ₄ [the welding start], step S ₁₈ [Requirement automatic management] and welding The main welding process includes a termination judgment (step S ₁₄ ). The preparation process is a process performed by the specification input unit 41 and the initial condition setting unit 42, and the main welding is a process performed by the condition automatic management correction unit 44. However, between the preparation process and the welding process, the welded joint and is determined whether the step S ₃ there is a gap (between the ski) is inserted into, if the gap is there a step S ₁₇ [gap Automatic management]. Note that the automatic management when there is this gap and the processing in the main welding are not directly related to the present invention, and therefore the description thereof is omitted.

The setting of the droplet transfer form of the present invention is performed in the above step S ₂ , and the condition setting is made according to the droplet transfer form of each joint specified at the time of inputting the basic specifications. The maintenance of the form is performed in step S ₁₈ .
That is, in step S _{2 of} FIG. 3, whether the welding speed is automatically set or the welding speed is manually set after the leg length is determined in step S ₂₁ [leg length setting] (determination of one-layer pile or multi-layer pile etc.). the determination (step S ₂₂₎ and, for each of the welding speed automatically set and the welding speed manual configuration, condition setting when pulse welding is specified (step S _23, step S _24), spray transfer type welding in MAG welding There condition setting if specified (step S _25, step S ₂₇₎ and the and conditions set when the short-circuit transfer type welding in MAG welding is specified (step S _26, step S ₂₈₎ is executed.

[0019] In the above steps S ₂₃ to S _28, first, determines the welding current I supplied from said welding power source 3 based on the welding speed of the determined leg or leg and manual input in step S ₂₁ to the wire 7. In the case of pulse welding, the average value of pulse current is determined. The actual pulse current consists of a base current and a peak current that exceeds the critical current. After this, the welding voltage V is defined by the following polynomial.

[0020]

[Equation 1] _{V = K a · I + K} b · EXT + K c I the welding current, EXT chip base distance, K _a,
K _b, K _c is a constant determined by using gas, wire, power supply, etc., particularly Kc is a constant that determines the shorted transitional spray transfer type. In the present invention, the constants K _a, K _b, K
_c is determined in advance by an experiment for each droplet transfer mode in which the distance between the tip base materials is changed, and each polynomial of the determined constants is prepared in the arithmetic expression memory 43. When the distance between the tip base metal and the droplet transfer form is specified for each joint at the time of inputting the basic specifications, a polynomial is selected according to the specified distance and the welding voltage V
To determine.

Here, the constants in the above polynomial for the spray transfer type and the short circuit transfer type are K _a and K _{b, respectively.}
Substantially equal, to increase the spray transfer type from short circuiting transfer-type K _c. Short circuit transfer type has arc voltage V _A (arc length)
This is because the welding voltage V that substantially determines the welding is smaller than the spray transfer type welding. In this way, the welding voltage V is defined by a polynomial consisting of a welding current term, a tip base metal distance term, and a voltage constant term, so that each welding under welding conditions according to an arbitrary tip base metal distance for each joint. The droplet transfer mode can be set. The commands to the welding power source 3 for outputting the set current and voltage are the command parameters P _I and P _{V, respectively.}
For each command signal v and i to the welding power source 3.

In this way, after the proper welding conditions of the target droplet transfer form are set according to the joint, in the main welding, the welding condition control for maintaining the specified droplet transfer form is performed. The welding condition for maintaining the droplet transfer form in the main welding is controlled by turning on the arc from the robot controller 5.
When a signal is output, the signal is received and the welding controller 4 receives it.
Step S ₅ [Welding parameters (I _a , V _a , S _a M
Sampling of R _a )] to Step S ₁₄ [Arc OFF
Signal input? ] Executing the control loop.

In sampling the above welding parameters,
The detection wire feeding speed MR _a , the detection welding current I _a , the detection welding voltage V _a, and the number of detected short-circuits S _a (including the fraction of less than 1 in the number of short-circuits per control interval) are sampled. Here, the number of detected short circuits S _a is the number of times per control interval at which the detected welding voltage V _a (voltage at the time of short circuit) falls below a predetermined threshold value.

The control loop performs the welding in step S ₇ [constant current control] depending on the determination in step S ₆ [constant current control] determined at the time of inputting the basic specifications, or step S _6.
8 [leg constant control] and Step S ₉ [penetration depth ensures control] branches to or complementarily performed welding. Welding with constant current control gives priority to keeping the current constant and keeps the penetration depth constant.It is suitable for welding thin plates and not only secures the welding strength, but also eliminates the loss due to the increase in welding current. Prevent occurrence.

Welding in which the constant leg length control and the control for ensuring the specified penetration depth are complementarily performed means that even if the current fluctuations, in particular, decrease during the constant leg length control by giving priority to the constant wire feeding speed. When it is below a certain value, the welding current is increased to secure the specified penetration depth, which is suitable for welding thick plates. The specified penetration depth value is set when entering the basic specifications. Further, the welding controller 4 executes step S ₁₀ [short-circuit count / arc length constant control] in the case of pulse welding while controlling the above current, and determines step S ₁₁ [with spray] in the case of mag welding. After that, step S ₁₂ [spray transfer type control] or step S ₁₃ [short circuit transfer type control] is executed.

The short-circuit count / arc length constant control in the above-mentioned pulse welding means that the detected short-circuit count _Sa is substantially equal to the short-circuit count set at the time of inputting the basic specifications (specifically, the lower limit value S ₁
And within the range of the upper limit S ₂ ), the voltage is controlled so as to be stable, and the spatter generation amount is suppressed and
The arc length is kept to a minimum (constant) to prevent undercuts and blow holes from occurring.

The spray transfer type control in the case of the above-mentioned MAG welding is a function of always maintaining the optimum voltage (called spraying voltage) of the spray transfer type welding set by the calculation in the initial condition setting means 42, if the disturbance causes disturbance. Even if the distance between the chip base materials EXT changes, the spraying voltage is calculated and corrected accordingly, and the voltage is controlled so that the detected welding voltage V _a becomes almost equal to the spraying voltage, and the optimum bead appearance is maintained. Is.

The short-circuit transition type control in the case of the above-mentioned mag welding is a function of always maintaining the optimum voltage of the short-circuit transition type welding set by the calculation in the initial condition setting means 42. When the voltage changes, the short-circuit transfer type voltage is calculated and corrected accordingly, and the detected welding voltage V
_The voltage is controlled so that a is approximately equal to the optimum voltage of the short-circuit transfer type, and the optimum bead appearance is maintained.

Further, in step S ₁₅ [EXT calculation] and step S ₁₆ [display (warning)] which are processed in parallel with the control loop, the distance between the chip base materials is calculated, and if this distance is too short, If it is too long, a warning is given, but the distance between the chip base materials obtained in this process is used for control in the case of mag welding. Specifically, in the pulse welding control, since the one pulse / one droplet transfer type is maintained, the determination in step _S42 [with pulse] in FIG. 5 is with pulse (Y) (at this time, from the welding controller 4 to the pulse mode). The mode switching signal 4a is commanded to the welding power source 3),
Step S ₄₃ [arc length calculating a] subsequent processing (corresponding to Step S ₁₀ of FIG. 4 [number of short circuits, the arc length constant control])
Proceed to. This arc length a is the distance between the chip base materials EXT,
It can be obtained by an arithmetic expression using the welding voltage V, the peak current I _a of the pulse welding current, the base current I _b, and the average current I _av as parameters.

The obtained calculated arc length a is compared with the maximum allowable arc length a ₀ in the following step S ₄₄ [a _O ≤a]. If the calculated arc length a is larger than the maximum allowable arc length a _o ,
Step S ₄₇ [P _V ′ = P _V −K ₁₄₆ ] is performed (K ₁₄₆ is a unit change amount), and step S ₅₀ [P _V ′ → D /
Then, the welding power source 3 is commanded by the voltage command signal v based on the corrected voltage command parameter P _V ′ in step S ₅₁ [P _V ′ analog signal output].

Next, if the operation arc length a maximum allowable arc length a _o is smaller than in step S _44, step S ₄₅ [S
_a ≦ S ₁ ], the detected short circuit frequency S _a obtained at the time of sampling is compared with the lower limit value S ₁ of the short circuit frequency. When the number of detected short circuits S _a is less than or equal to the lower limit value S _{1 of the} number of short circuits,
The calculation of step S ₄₈ [P _V ′ = P _V −ΔP _V ] is performed, and the process proceeds to step S ₅₀ [P _V ′ → D / A conversion]. As a result, when the number of short circuits decreases below the lower limit S ₁ , the correction voltage command parameter P _V ′ is decreased (the relationship between the number of short circuits and the arc length (arc voltage) is inversely proportional) and the number of short circuits is increased. .

If the calculated arc length a is smaller than the maximum allowable arc length a _{0 and} the judgment in step S ₄₅ is “the detected short circuit count S _a is larger than the lower limit S _{1 of the} short circuit count”, step S _{46 is executed.} Proceed to [S _a ≤ S ₂ ] and compare the detected short circuit count S _a with the upper limit S ₂ of the short circuit count. When the detected number of short circuits S _a is larger than the upper limit value S _{2 of the} number of short circuits, the calculation of step S ₄₉ [P _V ′ = P _V + ΔP _V ] is performed and step S ₅₀ [P _V ′ → D / A conversion ] To proceed. As a result, when the number of short circuits is larger than the upper limit value S ₂ , the correction voltage command parameter P _V ′ is increased and the number of short circuits is reduced.

Furthermore, if the determination of step S ₄₆ is "detected number of short circuits S _a is an upper limit values S ₁ following short number", the flow proceeds to step S ₁₄ without performing the correction of the initial voltage command parameters. In this way, the amount of spatter generated in pulse welding is suppressed, the arc length is kept to a minimum, and the one-pulse / one-droplet transfer type welding condition in which undercuts and blowholes are prevented from occurring is maintained.

Next, when the MAG welding is set at the time of inputting the basic specifications, the determination at step _S42 [with pulse] in FIG. 5 is MAG welding (N) (at this time, the welding controller 4
From the welding power source 3 to the normal mode switching signal 4a
Command) to the flow chart of FIG. In FIG. 6, it is further determined in step S ₁₁ whether spray transfer type welding or short circuit transfer type welding is performed. When performing spray transfer type welding, step S ₅₂ [EXT = f
(MR _a , I _a )] and the following PI control. When short-circuit transfer type welding is performed, the PI control is performed after step S ₅₇ .

The polynomial expression of Formula 1 used at the initial setting is again used for the calculation of each PI control of the spray transfer type welding and the short circuit transfer type welding. First, the detected welding current I _a and the detected welding current I _a detected in step S ₅ are detected. The inter-chip-base-material distance EXT is calculated from the wire feeding speed MR _a (steps S ₅₂ and S ₅₇ ), and I _a and EXT are substituted into the polynomial of Formula 1 in steps S ₅₃ and S ₅₈ to form a spray. Voltage V _sc
And the voltage V _C for the short-circuit transfer type is calculated.

Next, for example, in the spray transfer type PI control, a difference ΔV between the spraying voltage V _sc obtained by the above calculation and the detected welding voltage V _a is obtained (step S ₅₄ ), and then the difference ΔV is substantially obtained. The time T _{i +} (integral term) required to change the welding current until it becomes zero is obtained by integrating ΔV with time (step S ₅₅ ), and the initial voltage command parameter P _V is adjusted by the correction amount by ΔV and T _{i +.} Then, the corrected voltage parameter P _V ′ is calculated (step S ₅₆ ).

The same applies to the PI control of the short-circuit transfer type. Step S ₅₉ is the proportional term V _C -V _a , step S ₆₀ is the integral term T _{i +} , and step S ₆₁ is the corrected voltage command parameter P _V ′.
Is calculated. As described above, in the present invention, even during welding, even if the distance between the tip base metals changes and the arc length changes and the wire feeding speed changes, the distance between the tip base materials is calculated from the wire feeding speed and the detected welding current. , Welding voltage is calculated by substituting these calculated tip base metal distance and detected welding current into the polynomial at the time of initial setting, and the welding voltage is controlled so that the difference with the detected welding voltage becomes almost zero. It can be corrected to an optimum voltage that maintains the specified droplet transfer morphology regardless of the variation in the distance between the tip base materials.

As another embodiment, in the case of the spray transfer type, as in the case of pulse welding, the arc length and the number of short circuits are calculated by the program of FIG. 5 and the command parameter of the welding voltage is corrected from the detected welding voltage. You may. According to this, even in the case of spray transfer type, like pulse welding,
It is possible to maintain the droplet transfer form with the arc length kept constant.

In the claims of the present invention, in the case of pulse welding and spray transfer type welding, keeping the arc length constant is not a requirement, but the requirements of step S ₄₃ , step S ₄₄ and step S ₄₇ are satisfied. It is also possible to add.

[0040]

As described above, according to the present invention, proper welding conditions for the intended droplet transfer form are set according to the joint, and the droplet transfer form specified for each joint during welding is set. The function of selecting and switching can be incorporated into the automatic welding program. Particularly, in the modes of claims 2, 3, and 4, it is possible to perform management to maintain the designated droplet transfer mode while welding while satisfying the welding quality items.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing the entire equipment embodying the present invention.

FIG. 2 is a conceptual diagram of FIG. 1 when the welding controller is represented by hardware.

FIG. 3 is a flowchart showing an overall operation centered on initial setting of a droplet transfer form setting management device for arc welding according to an embodiment of the present invention.

FIG. 4 is a flowchart showing an overall operation centered on control during welding of the droplet transfer pattern setting management device for arc welding according to the embodiment of the present invention.

FIG. 5 is a flowchart showing a voltage control program according to the present invention in the case of pulse welding.

FIG. 6 is a flowchart showing a program for voltage control according to the present invention in the case of mag welding.

[Explanation of symbols]

1 is a welding torch, 2 is a robot, 3 is a welding power source, 4 is a welding controller, 12 is an encoder, 14 is a rotary actuator, 44 is a condition automatic management correction means, EXT is a distance between chip base materials, I is a welding current and V welding voltage, I _a is detected welding current, V _a is detected welding voltage, MR _a detection wire feed rate, i is the current command signal, v is the voltage command signal, common to the same elements in the drawings Is attached.

Claims (4)

[Claims] 1. A welding power source capable of switching between a pulse mode for pulsing a welding current applied to a wire through a tip of a welding torch and a normal mode for directing or alternating current, and a welding quality item required for each joint. The welding controller sends a mode switching signal for switching between the pulse mode and the normal mode during welding to the welding power source according to the droplet transfer mode specified by the operator at the time of inputting the specifications so as to satisfy Is defined by a polynomial consisting of a welding current term, a tip base metal distance term, and a voltage constant term determined by each droplet transfer mode from the welding power source to the wire. By selecting the above polynomial, the welding voltage for each droplet transfer type of pulse welding, MAG welding spray transfer type and short-circuit transfer type can be set. Droplet transfer mode setting management device of an arc welding, characterized by. 2. The welding controller detects the number of short-circuit phenomena such that the number of short-circuit phenomena in which the tip of the wire comes into contact with the base metal is a preset number of times during welding in the pulse welding setting and performs welding. The droplet transfer form setting management device for arc welding according to claim 1, wherein the droplet transfer form for pulse welding is maintained by controlling the voltage. 3. The welding controller controls the welding voltage by substituting the distance between the tip base metal obtained from the detected wire feeding speed and the detected welding current into the above polynomial during the welding of the spray transfer type or the short circuit transfer type setting. By doing so, each droplet transfer form is maintained, and the droplet transfer form setting management device for arc welding according to claim 1 or 2, characterized in that. 4. The welding controller detects the number of short-circuiting phenomena such that the number of short-circuiting phenomena in which the tip of the wire comes into contact with the base metal is a preset number of times even in the spray transfer type setting. The welding voltage setting control device for arc welding according to claim 2, wherein the welding voltage is controlled.