Submerged arc welding system

Abstract

To provide a submerged arc welding system that allows even operators with little experience in submerged arc welding to properly adjust the amount of sprayed flux.SOLUTION: A welding system A1 for performing submerged arc welding includes: a welding power supply 2 equipped with an inverter circuit 25 to supply power; a sprayer 7 for spraying flux 79 onto a workpiece W; and a controller 1 for controlling the welding power supply 2 and the sprayer 7. The sprayer 7 automatically varies the amount of flux 79 sprayed, depending on at least one of the welding current, welding voltage, welding speed, stick-out length, and groove angle.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a submerged arc welding system for performing submerged arc welding. [Background technology]

[0002] Submerged arc welding has been known for some time. In submerged arc welding, granular flux is spread on the workpiece, a welding wire is fed into the flux, and an arc is generated between the tip of the welding wire and the workpiece to perform welding. In submerged arc welding, a large current is passed through a large diameter welding wire, thereby enabling high efficiency welding of thick plates.

[0003] The flux shields the periphery of the arc and stabilizes the arc. In addition, a part of the flux is melted by the arc heat to become slag, which protects the molten metal from the atmosphere and also shapes the bead when the molten metal solidifies. If the flux is not sprayed enough, the welded part may be exposed to the atmosphere, resulting in poor welding. Conversely, if too much flux is sprayed, the bead shape may become rough. Therefore, the amount of flux sprayed needs to be appropriately adjusted. Patent Document 1 discloses an example of a submerged arc welding device. The submerged arc welding device supplies flux stored in a hopper to the welded part through a nozzle (hose). The operator adjusts the amount of flux sprayed by adjusting a valve. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2000-117442 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in order to properly adjust the amount of flux to be sprayed, a worker with a lot of experience, such as a skilled worker, has difficulty in properly adjusting the amount of flux to be sprayed by a worker with little experience.

[0006] The present invention has been devised in light of the above-mentioned circumstances, and an object of the present invention is to provide a submerged arc welding system that enables even an operator with little experience in submerged arc welding to appropriately adjust the amount of flux sprayed. [Means for solving the problem]

[0007] The submerged arc welding system provided by the present invention is a submerged arc welding system for performing submerged arc welding, and includes a welding power supply unit having an inverter circuit for supplying power, a sprayer unit for spraying flux onto a workpiece, and a control device for controlling the welding power supply unit and the sprayer unit, and the sprayer unit automatically changes the amount of the flux sprayed in response to at least one of the welding current, welding voltage, welding speed, extension length, and groove angle.

[0008] The "welding current" is the current flowing through the electrode during welding, and may be a set value of the welding current or a measured value of the welding current that is actually measured. The "welding voltage" is the voltage applied between the workpiece and the tip of the electrode during welding, and may be a set value of the welding voltage or a measured value of the welding voltage that is actually measured. The "welding speed" is the speed at which the weld bead is placed, and a set value of the phase speed of the electrode (carriage) is used. The "extension length" is the length by which the electrode (welding wire) protrudes from the tip of the contact tip, and a set value of the extension length is used. The "groove angle" is the angle of the groove, which is a groove-shaped depression provided in the workpiece, and a set value of the groove angle is used.

[0009] In a preferred embodiment of the present invention, the control device is provided with a spray amount setting unit that sets a spray setting value corresponding to the spray amount, and the spraying device is provided with a spray amount changing mechanism that changes the spray amount in accordance with the spray setting value.

[0010] In a preferred embodiment of the present invention, the spray amount setting unit sets a spray set value based on the welding current, and corrects the spray set value in accordance with the welding voltage.

[0011] In a preferred embodiment of the present invention, the spraying device further includes a hopper for storing the flux and a hose for guiding the flux from the hopper onto the workpiece, and the spray amount change mechanism changes the height of the tip of the hose from the workpiece in accordance with the spray setting value.

[0012] In a preferred embodiment of the present invention, the spraying device further includes a hopper for storing the flux and a hose for guiding the flux from the hopper onto the workpiece, and the spraying amount changing mechanism includes an opening / closing valve arranged between the hopper and the hose, and changes the opening degree of the opening / closing valve in accordance with the spraying set value. Effect of the Invention

[0013] According to the present invention, the spraying device automatically changes the amount of flux sprayed in accordance with at least one of the welding current, welding voltage, welding speed, extension length, and groove angle. Therefore, the spraying device can automatically adjust and spray an appropriate amount of flux. As a result, the submerged arc welding system according to the present invention allows even an operator with little experience in submerged arc welding to appropriately adjust the amount of flux sprayed. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a diagram for explaining a welding system according to a first embodiment, where (a) is a block diagram showing the overall configuration of the welding system, and (b) is a block diagram showing the internal configuration of a welding power supply and a control device. [Diagram 2] 11 is a diagram for explaining adjustment of the spray amount by the spray device. FIG. [Diagram 3]5A and 5B are diagrams for explaining a welding system according to a second embodiment, where FIG. 5A is a block diagram showing the overall configuration of the welding system, and FIG. 5B is a block diagram showing the internal configurations of a welding power supply and a control device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0016] [First embodiment] Fig. 1 and Fig. 2 are diagrams for explaining a welding system A1 according to a first embodiment. Fig. 1(a) is a block diagram showing the overall configuration of the welding system A1. Fig. 1(b) is a block diagram showing the internal configuration of a welding power supply 2 and a control device 1. Fig. 2 is a diagram for explaining adjustment of the amount of spraying by a spraying device 7.

[0017] The welding system A1 is a welding system for performing submerged arc welding. As shown in FIG. 1(a), the welding system A1 includes a control device 1, a welding power supply 2, a carriage 4, a wire feeder 5, a wire reel 6, a sprayer 7, and an electrode 8. The welding system A1 causes the sprayer 7 to spray granular flux 79 and the wire feeder 5 to feed the welding wire into the flux 79 while moving the carriage 4 along the welding line of the workpiece W. The welding wire is supplied from the wire reel 6. The welding power supply 2 converts AC power supplied from a commercial power source P into power suitable for welding and outputs it, and generates an arc between the electrode 8, which is the tip of the welding wire, and the workpiece W inside the flux 79. Welding is performed by the heat of the arc. As a result, welding is performed along the welding line of the workpiece W. Instead of using the carriage 4, the workpiece W may be moved or rotated.

[0018] The control device 1 performs various controls of the welding system A1. The control device 1 may be a general-purpose computer with a program installed therein for performing various controls of the welding system A1, or may be a dedicated device for controlling the welding system A1. The control device 1 moves the carriage 4 at a predetermined moving speed. The moving speed is set according to the material and thickness of the workpiece W. The control device 1 instructs the spraying device 7 to start and end the spraying of the flux 79. The control device 1 also instructs the spraying device 7 as to the amount of the flux 79 to be sprayed. The control device 1 instructs the wire feeder 5 to start and stop the feeding of the welding wire and the feeding speed of the welding wire. The feeding speed is set according to the welding current to be set. The control device 1 instructs the welding power source 2 to output power. Details of the method in which the control device 1 instructs the spraying device 7 as to the amount of the flux 79 to be sprayed will be described later.

[0019] Welding power supply 2 converts AC power supplied from commercial power source P into AC power of a desired frequency and outputs the AC power. As shown in Fig. 1(b), welding power supply 2 includes a rectifying and smoothing circuit 21, an inverter circuit 22, a transformer 23, a rectifying and smoothing circuit 24, an inverter circuit 25, a current sensor 26, a voltage sensor 27, and a control circuit 28.

[0020] The rectifying and smoothing circuit 21 converts AC power input from the commercial power source P into DC power and outputs it. The inverter circuit 22 converts the DC power input from the rectifying and smoothing circuit 21 into high-frequency power and outputs it by switching the switching elements according to an output control drive signal input from the control circuit 28. The transformer 23 transforms the high-frequency voltage output by the inverter circuit 22 and outputs it to the rectifying and smoothing circuit 24.

[0021] The rectifying and smoothing circuit 24 converts the high frequency power input from the transformer 23 into DC power and outputs it. The inverter circuit 25 converts the DC power input from the rectifying and smoothing circuit 24 into AC power and outputs it by switching the switching elements according to a switching drive signal input from the control circuit 28. The inverter circuit 25 switches between a positive polarity in which the potential of the output terminal a (connected to the workpiece W) is higher than the potential of the output terminal b (connected to the welding wire), and a reverse polarity in which the potential of the output terminal a is lower than the potential of the output terminal b.

[0022] Current sensor 26 detects the output current of welding power supply 2, and in this embodiment, is disposed on a connection line connecting one output terminal of inverter circuit 25 and output terminal a. The output current of welding power supply 2 detected by current sensor 26 is approximately equal to the current flowing through electrode 8. Current sensor 26 outputs a current value signal corresponding to the detected current instantaneous value to control circuit 28 and control device 1. Voltage sensor 27 detects the output voltage of welding power supply 2, and in this embodiment, detects the inter-terminal voltage between output terminal a and output terminal b. This voltage is approximately equal to the voltage applied between workpiece W and the tip of electrode 8. Voltage sensor 27 outputs a voltage value signal corresponding to the detected voltage instantaneous value to control circuit 28 and control device 1.

[0023] Control circuit 28 is a circuit for controlling welding power supply 2, and is realized by, for example, a microcomputer. Control circuit 28 receives a current value signal from current sensor 26, a voltage value signal from voltage sensor 27, and various command signals and various set values ​​from control device 1. Control circuit 28 then outputs drive signals to inverter circuit 22 and inverter circuit 25, respectively.

[0024] When the control circuit 28 receives a command signal from the control device 1 to start power output, it starts outputting drive signals to the inverter circuits 22 and 25, respectively, to start power output. When the control circuit 28 receives a command signal from the control device 1 to stop power output, it stops outputting the drive signals to stop power output.

[0025] Control circuit 28 also calculates the effective current value from the current value signal input from current sensor 26. Then, control circuit 28 generates an output control drive signal for controlling the switching elements of inverter circuit 22 based on the effective current value and a current command value (set value of welding current) input from control device 1, and outputs the signal to inverter circuit 22. That is, control circuit 28 performs feedback control (constant current control) so that the effective current value coincides with the current command value. Control circuit 28 can also generate an output control drive signal based on a voltage value signal and a voltage command value (set value of welding voltage) input from voltage sensor 27, and perform feedback control (constant voltage control) so that the effective voltage value coincides with the voltage command value.

[0026] Furthermore, the control circuit 28 generates a switching drive signal for controlling the switching elements of the inverter circuit 25 based on the current value signal input from the current sensor 26 and the waveform command signal generated inside, and outputs the signal to the inverter circuit 25. That is, the control circuit 28 performs feedback control so that the waveform of the output current matches the waveform commanded by the waveform command signal. In this embodiment, the waveform command signal is a sine wave signal. The control circuit 28 generates a switching drive signal based on the waveform command signal and outputs the signal to the inverter circuit 25, so that the inverter circuit 25 outputs a sine wave AC current according to the waveform command signal. The control circuit 28 may generate the switching drive signal based only on the waveform command signal, without using the instantaneous value of the output current.

[0027] Furthermore, when a command signal for DC output is input from the control device 1, the control circuit 28 outputs a switching drive signal to the inverter circuit 25 as a signal for fixing a predetermined switching element to an ON state and fixing the other switching elements to an OFF state. For example, when the state of each switching element is fixed so that the output terminal on the positive side of the rectifying smoothing circuit 24 is connected to the output terminal a and the output terminal on the negative side of the rectifying smoothing circuit 24 is connected to the output terminal b, the welding power supply 2 outputs DC power with the output terminal a as the positive electrode and the output terminal b as the negative electrode. In other words, the welding system A1 is an AC / DC dual-purpose welding system that can output not only AC power but also DC power. Furthermore, the welding power supply 2 can control the output current based on the current command value input from the control device 1. Therefore, the welding system A1 can appropriately control the output current. The configuration of the welding power supply 2 is not limited.

[0028] Next, the details of the spraying device 7 and the method of spraying the flux 79 will be described.

[0029] The appropriate amount of flux 79 to be scattered varies depending on various welding conditions. It is empirically known that the appropriate amount of flux 79 to be scattered varies depending on the welding current, welding voltage, welding speed, extension length, and groove angle. In addition, there is a correlation between each of the above welding conditions and the appropriate amount of flux 79 to be scattered. The welding current is a current that flows through the electrode 8 during welding, and the larger the current value, the larger the appropriate amount of flux 79 to be scattered. The welding voltage is a voltage applied between the workpiece W and the tip of the electrode 8 during welding, and the larger the voltage value, the larger the appropriate amount of flux 79 to be scattered. The welding speed is the speed at which the weld bead is placed, and is generally expressed as bead length per minute. In this embodiment, the welding speed corresponds to the moving speed of the carriage 4. The higher the welding speed, the larger the appropriate amount of flux 79 to be scattered. The extension length is the length of the welding wire that protrudes from the tip of the contact tip, and the larger the extension length, the larger the appropriate amount of flux 79 to be scattered. The extension length may be the distance from the tip of the contact tip to the arc, or the distance from the tip of the contact tip to the workpiece W. The groove angle is the angle of the groove, which is a groove-shaped depression provided in the workpiece W, and the larger the groove angle is, the greater the appropriate amount of flux 79 to be sprayed. The control device 1 determines the amount of spray based on each welding condition, and instructs the spraying device 7 to spray the determined amount of flux 79. Specifically, the control device 1 outputs a spray setting value corresponding to the amount of spray to the spraying device 7. In this embodiment, the spray setting value is increased as the amount of spray is increased.

[0030] The spraying device 7 is a device that sprays flux 79 in response to an instruction from the control device 1, and includes a hopper 71, an opening / closing valve 72, a hose 73, and a moving mechanism 74. The hopper 71 stores the flux 79. The hose 73 guides the flux 79 stored in the hopper 71 from the hopper 71 onto the workpiece W.

[0031] The opening / closing valve 72 is disposed between an opening provided at the bottom of the hopper 71 and the hose 73, and is switched between an open state and a closed state in response to an instruction from the control device 1. The opening / closing valve 72 is, for example, a solenoid valve. When the opening / closing valve 72 is in an open state, the opening / closing valve 72 allows the flux 79 stored in the hopper 71 to pass through. This causes the flux 79 to be sprayed through the hose 73. On the other hand, when the opening / closing valve 72 is in a closed state, the opening / closing valve 72 does not allow the flux 79 stored in the hopper 71 to pass through. Therefore, the flux 79 is not sprayed. The opening / closing valve 72 may be disposed in the middle of the hose 73. In addition, the configuration of the opening / closing valve 72 is not limited. For example, the opening / closing valve 72 may be configured to be manually switched between an open state and a closed state, rather than in response to an instruction from the control device 1.

[0032] The moving mechanism 74 is a mechanism that moves the tip of the hose 73 up and down according to the spray setting value (signal based on the spray setting value) input from the control device 1. As shown in FIG. 2(a), the moving mechanism 74 moves the tip of the hose 73 up and down by moving a moving part 741, to which the vicinity of the tip of the hose 73 is fixed, up and down along a rail 742 fixed to the cart 4 and extending in the vertical direction. This changes the height H of the tip of the hose 73 from the workpiece W, and changes the amount of flux 79 sprayed. FIG. 2(b) shows a state in which the moving part 741 has moved downward and the height H has become smaller. In this case, when the flux 79 sprayed on the workpiece W reaches the tip of the hose 73, the flux 79 is no longer discharged, so the amount of flux 79 sprayed decreases. FIG. 2(c) shows a state in which the moving part 741 has moved upward and the height H has become larger. In this case, the flux 79 sprayed on the workpieces W is discharged until it reaches the tip of the hose 73, so that the amount of flux 79 sprayed is large. In this manner, the moving mechanism 74 changes the height H according to the spray setting value input from the control device 1, thereby changing the amount of flux 79 sprayed. Note that the specific configuration of the moving mechanism 74 is not limited as long as it changes the height H. For example, the moving mechanism 74 may be a so-called ball screw mechanism that includes a screw shaft having a screw groove formed thereon instead of the rail 742, and moves the moving part 741 by rotating the screw shaft about its axis.

[0033] The control device 1 instructs the spraying device 7 on the amount of flux 79 to be sprayed. Specifically, the control device 1 determines a spraying set value corresponding to the amount of spraying based on each welding condition, and outputs the determined value to the spraying device 7. In this embodiment, the spraying set value is set to a value corresponding to the height H of the tip of the hose 73 from the workpiece W. The spraying device 7 changes the amount of flux 79 to be sprayed by causing the moving mechanism 74 to move the tip of the hose 73 up and down in accordance with the spraying set value. The control device 1 includes a setting unit 11 and a spraying amount setting unit 12 as shown in FIG. 1(b) as a configuration for instructing the spraying device 7 on the amount of flux 79 to be sprayed.

[0034] The setting unit 11 is configured to set each welding condition. The setting unit 11 sets a value input by an operator by operating an operation unit (not shown). The setting unit 11 sets each set value such as the welding current, welding voltage, welding speed (movement speed of the carriage 4), extension length, groove angle, wire feed speed, wire material, wire diameter, material of the workpiece W, and thickness of the workpiece W. The setting unit 11 may set a value calculated from the set values ​​of other welding conditions as the set value. The setting unit 11 outputs each set value of the welding current, welding voltage, welding speed, extension length, and groove angle to the spray amount setting unit 12. The setting unit 11 also outputs the set value of the welding current (current command value) and the set value of the welding voltage (voltage command value) to the control circuit 28 of the welding power supply 2.

[0035] The scattering amount setting unit 12 sets a scattering set value corresponding to an appropriate scattering amount based on each welding condition. In this embodiment, the scattering amount setting unit 12 first sets a scattering set value based on the welding current. Specifically, the scattering amount setting unit 12 sets a scattering set value corresponding to the set value of the welding current set by the setting unit 11. The scattering amount setting unit 12 reads out a scattering set value corresponding to the set value of the welding current from a memory unit in which a scattering set value corresponding to the set value of the welding current is stored, and sets the scattering set value by linear interpolation. The scattering amount setting unit 12 may calculate a scattering set value corresponding to the set value of the welding current based on an arithmetic expression. The scattering amount setting unit 12 sets a scattering set value to a larger value as the set value of the welding current increases. For example, the dispersion amount setting unit 12 sets the dispersion setting value so that the height H is 30 mm when the welding current setting value is 800 A, sets the dispersion setting value so that the height H is 20 mm when the welding current setting value is 600 A, and sets the dispersion setting value so that the height H is 40 mm when the welding current setting value is 1000 A.

[0036] Next, the scattering amount setting unit 12 corrects the scattering set value according to each of the set values ​​of the welding voltage, the welding speed, the extension length, and the groove angle set by the setting unit 11. The scattering amount setting unit 12 corrects the scattering set value by adding a value corresponding to the difference between the set value of the welding voltage and the reference value. The scattering amount setting unit 12 increases the scattering set value when the set value of the welding voltage is greater than the reference value, and decreases the scattering set value when the set value of the welding voltage is smaller than the reference value. For example, the scattering amount setting unit 12 corrects the scattering set value so that the height H increases by 1 mm every time the set value of the welding voltage increases by 2 V from the reference value. Similarly, the scattering amount setting unit 12 corrects the scattering set value by adding a value corresponding to the difference between the set value of the welding speed and the reference value, adding a value corresponding to the difference between the set value of the extension length and the reference value, and adding a value corresponding to the difference between the set value of the groove angle and the reference value. The scattering amount setting unit 12 may correct the scattering set value by multiplying a value corresponding to the difference between each set value and the reference value. The method of correction performed by the spray amount setting unit 12 is not limited. For example, the spray amount setting unit 12 may perform correction according to any one of the set values ​​of the welding voltage, welding speed, extension length, and groove angle, rather than performing correction according to all of the set values. Also, the spray amount setting unit 12 may output the spray set value based on the welding current as is without performing correction. The spray amount setting unit 12 outputs the corrected spray set value to the movement mechanism 74 of the spraying device 7.

[0037] The scattering amount setting unit 12 may use the actual measurement value of the welding current detected by the current sensor 26 instead of the set value of the welding current. Also, the actual measurement value of the welding voltage detected by the voltage sensor 27 may be used instead of the set value of the welding voltage. Also, the method of setting the scattering set value by the scattering amount setting unit 12 is not limited. For example, the scattering amount setting unit 12 may set a scattering set value based on the welding voltage and correct it according to other welding conditions. Also, the scattering amount setting unit 12 may set a scattering set value based on the welding current and the welding voltage and correct it according to other welding conditions. The scattering amount setting unit 12 may set the scattering set value according to at least one of the welding current, the welding voltage, the welding speed, the extension length, and the groove angle. Also, the scattering amount setting unit 12 may use other welding conditions such as the wire feed speed, the wire material, the wire diameter, the material of the workpiece W, and the thickness of the workpiece W in setting the scattering set value. In welding system A1, welding power supply 2 performs feedback control of the welding current or welding voltage using inverter circuit 22, making it possible to automatically adjust the amount of flux 79 sprayed according to the welding current or welding voltage.

[0038] Next, the operation and effects of the welding system A1 according to this embodiment will be described.

[0039] According to this embodiment, the spray amount setting unit 12 sets a spray set value corresponding to an appropriate spray amount based on each welding condition. The spraying device 7 changes the spray amount of the flux 79 according to the spray set value. In other words, the spraying device 7 can automatically adjust the amount of the flux 79 to an appropriate amount according to each welding condition and spray it. This allows the welding system A1 to appropriately adjust the spray amount of the flux 79 even if the worker has little experience with submerged arc welding.

[0040] Also, according to this embodiment, the spray amount setting unit 12 sets a spray set value based on the welding current, and corrects the spray set value according to the welding voltage. Therefore, the spray amount setting unit 12 can appropriately set the spray set value. Furthermore, the spray amount setting unit 12 corrects the spray set value according to the welding speed, the extension length, and the groove angle. Therefore, the spray amount setting unit 12 can more appropriately set the spray set value.

[0041] Furthermore, according to this embodiment, the movement mechanism 74 moves the tip of the hose 73 up and down in accordance with the set spray value. This changes the height H of the tip of the hose 73 from the workpiece W, and changes the spray amount of the flux 79. Therefore, the spraying device 7 can spray the flux 79 at a spray amount according to the set spray value.

[0042] Second Embodiment Fig. 3 is a diagram for explaining a welding system A2 according to a second embodiment. Fig. 3(a) is a block diagram showing the overall configuration of the welding system A2. Fig. 3(b) is a block diagram showing the internal configuration of a welding power supply 2 and a control device 1. In Fig. 3, elements that are the same as or similar to those in the first embodiment are given the same reference numerals as those in the first embodiment. The welding system A2 according to this embodiment differs from the welding system A1 according to the first embodiment in the method of adjusting the amount of flux 79 sprayed.

[0043] In this embodiment, the hose 73 is fixed to the cart 4, and the position of the tip of the hose 73 cannot be changed. In this embodiment, the opening of the opening valve 72 is adjusted to adjust the amount of flux 79 to be sprayed. The opening of the opening valve 72 according to this embodiment can be adjusted from 0% to 100%, and the opening is adjusted according to an instruction from the control device 1. When the opening is 0%, the opening valve 72 is closed and does not allow the flux 79 to pass. When the opening is 100%, the opening valve 72 is fully open and allows the maximum amount of flux 79 to pass. Therefore, the amount of flux 79 to be sprayed is maximized. The spray amount setting unit 12 sets a value corresponding to the opening of the opening valve 72 as a spray setting value, and outputs the spray setting value to the opening valve 72. The opening valve 72 changes the opening according to the spray setting value (a signal based on the spray setting value) input from the spray amount setting unit 12, thereby changing the amount of flux 79 to be sprayed.

[0044] In this embodiment, the spray amount setting unit 12 also sets a spray set value corresponding to an appropriate spray amount based on each welding condition. The spray device 7 changes the spray amount of the flux 79 according to the spray set value. Therefore, even an operator with little experience in submerged arc welding can appropriately adjust the spray amount of the flux 79 in the welding system A2. Furthermore, according to this embodiment, the welding system A2 has a common configuration with the welding system A1, and thus has the same effect as the welding system A1. Furthermore, according to this embodiment, the opening and closing valve 72 changes the spray amount of the flux 79 by changing the opening degree according to the spray set value. Therefore, the spray device 7 can spray the flux 79 at a spray amount according to the spray set value.

[0045] The welding system according to the present invention is not limited to the above-described embodiment, and the specific configuration of each part of the welding system according to the present invention can be freely designed in various ways. [Explanation of symbols]

[0046] A1: welding system, 1: control device, 12: spray amount setting unit, 2: welding power supply device, 22: inverter circuit, 7: spray device, 72: opening / closing valve, 74: moving mechanism

Claims

1. 1. A submerged arc welding system for performing submerged arc welding, comprising: a welding power supply device having an inverter circuit for supplying power; A spraying device for spraying flux onto the workpiece; a control device for controlling the welding power supply and the spraying device; Equipped with The spraying device automatically changes the amount of the flux sprayed in accordance with at least one of a welding current, a welding voltage, a welding speed, a welding extension length, and a groove angle. Submerged arc welding system.

2. The control device includes a spray amount setting unit that sets a spray setting value corresponding to the spray amount, The spraying device is provided with a spray amount changing mechanism that changes the spray amount according to the spray setting value.

2. The submerged arc welding system of claim 1.

3. The dispersion amount setting unit sets a dispersion set value based on the welding current and corrects the dispersion set value in accordance with the welding voltage.

3. The submerged arc welding system of claim 2.

4. The spraying device is A hopper for storing the flux; a hose for directing the flux from the hopper onto the workpiece; Further equipped with The spray amount change mechanism changes the height of the tip of the hose from the workpiece in accordance with the spray setting value.

3. The submerged arc welding system of claim 2.

5. The spraying device is A hopper for storing the flux; a hose for directing the flux from the hopper onto the workpiece; Further equipped with The spray amount change mechanism is An opening and closing valve is disposed between the hopper and the hose, changing the opening degree of the opening / closing valve in accordance with the spray setting value; 3. The submerged arc welding system of claim 2.

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