Arc welding system

Abstract

To provide a welding system that can wholly manage welding using a plurality of electrodes.SOLUTION: A welding system A1 is provided with: a plurality of electrodes 8 that form one welding bead on an object W to be welded, by fusing; a plurality of welding power supply devices 2 that respectively supply electric power to any of the plurality of electrodes 8; and a managing device 61 that receives information concerning welding from the plurality of welding power supply devices 2. The plurality of welding power supply devices 2 include a welding power supply device 2a and a welding power supply device 2b. The managing device 61 comprises a calculating part 65 that performs calculation using information received from the welding power supply device 2a and information received from the welding power supply device 2a.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] Submerged arc welding has been known for some time. In submerged arc welding, granular flux is dispersed on the workpiece, a welding wire is fed into the flux, and an arc is generated between the tip of the welding wire (electrode) and the workpiece to perform welding. In submerged arc welding, welding is performed while moving the welding point, for example, by running a cart along the welding line. In submerged arc welding, a large current is passed through a large-diameter welding wire, allowing thick plates to be welded with high efficiency. In addition, a method of submerged arc welding in which multiple electrodes are used to generate an arc at each electrode is known.

[0003] Furthermore, in welding work, there are cases where it is required to manage the heat input to confirm that welding is being performed properly, or to calculate energy efficiency in accordance with the ISO 14000 standard. Patent Document 1 discloses a welding heat input measuring device that can measure the heat input. This welding heat input measuring device calculates the welding heat input from the welding voltage, welding current, and welding time detected by the welding machine, and the input weld length. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-71564 Summary of the Invention [Problem to be solved by the invention]

[0005] In submerged arc welding using multiple electrodes, each welding power supply that supplies power to each electrode manages its own heat input. Therefore, when welding using multiple electrodes, the heat input from each welding power supply corresponding to each electrode must be output to a file and then added manually or using a macro to calculate the overall heat input for the welding. Because calculating the heat input takes time, there is a problem in that the heat input cannot be checked promptly after the welding is completed. Because each welding power supply manages only its own welding information, in welding using multiple electrodes, it is not possible to consider not only the heat input but also the influence of welding by other welding power supplies, and therefore it is not possible to manage the welding as a whole.

[0006] The present invention has been devised in light of the above circumstances, and has an object to provide a welding system that can manage the entire welding process when a plurality of electrodes are used. [Means for solving the problem]

[0007] The arc welding system provided by the present invention comprises a plurality of electrodes that melt to form a single weld bead on a workpiece, a plurality of welding power supplies, each supplying power to one of the plurality of electrodes, and a management device that receives information about welding from the plurality of welding power supplies, wherein the plurality of welding power supplies include a first welding power supply and a second welding power supply, and the management device comprises a calculation unit that performs calculations using the information received from the first welding power supply and the information received from the second welding power supply.

[0008] In a preferred embodiment of the present invention, the welding machine further comprises a carriage on which the plurality of electrodes are mounted and which travels along the welding line.

[0009] The management device receives the detected voltages and detected currents detected by each of the multiple welding power sources, and the calculation unit calculates the amount of heat input to the workpiece using each detected voltage and each detected current and the traveling speed of the cart.

[0010] The management device receives the detected voltages and currents detected by each of the multiple welding power supplies, and the calculation unit generates an estimated image of the weld bead shape of the workpiece using each detected voltage and each detected current, the traveling speed of the carriage, the EN ratio of each welding power supply, and the phase difference between each welding power supply. [Effects of the Invention]

[0011] According to the present invention, the calculation unit of the management device performs calculations using information received from the first welding power supply and information received from the second welding power supply, and therefore the calculation unit can perform calculations that take into account the influence of welding by each of the first and second welding power supplies. As a result, the welding system according to the present invention can manage the welding as a whole when a plurality of electrodes are used for welding. [Brief explanation of the drawings]

[0012] [Figure 1] 1A and 1B are diagrams for explaining a welding system according to a first embodiment, in which FIG. 1A is a block diagram showing the overall configuration of the welding system, and FIG. 1B is a block diagram showing the internal configurations of a plurality of welding power supplies, a control device, and a management device. [Figure 2] FIG. 10 is a diagram showing an example of a display screen that the management device causes the display unit of the display unit to display. [Figure 3] 10A and 10B are diagrams for explaining a welding system according to a second embodiment, in which FIG. 10A is a block diagram showing the internal configurations of a plurality of welding power supplies, a control device, and a management device, and FIG. 10B is a diagram for explaining a bead shape image generating unit provided in a calculation unit of the management device. [Figure 4] 10A and 10B are diagrams for explaining a welding system according to a third embodiment, in which FIG. 10A is a block diagram showing the overall configuration of the welding system, and FIG. 10B is a block diagram showing the internal configurations of a plurality of welding power supplies, a control device, and a management device. DETAILED DESCRIPTION OF THE INVENTION

[0013] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0014] [First embodiment] FIG. 1 is a diagram illustrating 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 configurations of multiple welding power supplies, a control device, and a management device. Note that in FIG. 1(b), the internal configuration of one of the welding power supplies is omitted.

[0015] Welding system A1 is a welding system for performing submerged arc welding. As shown in FIG. 1(a), welding system A1 includes a control device 1, a carriage 4, a sprayer 7, a management device 61, and a plurality of welding power sources 2, welding torches 3, wire feeders 5, wire reels 6, and electrodes 8. While traveling along a weld line of workpieces W, welding system A1 controls sprayer 7 to spray granular flux 79 and wire feeder 5 to feed welding wire into the flux 79. The welding wire is supplied from wire reel 6. Welding power source 2 converts AC power supplied from commercial power source P into power suitable for welding and outputs it. An arc is generated within the flux 79 between electrode 8, which is the tip of the welding wire, and workpiece W. Heat from the arc causes welding. This results in welding along the weld line of workpieces W.

[0016] Welding torch 3 guides the welding wire fed by wire feeder 5 to the welding point. The tip of the welding wire becomes electrode 8, which protrudes from the tip of welding torch 3. Welding torch 3 has a contact tip (not shown) located at the tip and connected to welding power supply 2. Welding power supply 2 applies a welding current to the welding wire that contacts the contact tip. Welding torch 3 is mounted on carriage 4 and moves as carriage 4 moves. Therefore, electrode 8 is also mounted on carriage 4 and moves as carriage 4 moves. Welding torch 3 may be fixed directly to carriage 4 or indirectly via an arm or the like.

[0017] In this embodiment, welding system A1 includes a welding power supply 2, welding torches 3, wire feeders 5, wire reels 6, and two electrodes 8. Welding system A1 performs so-called tandem welding, in which two electrodes 8 pass the same welding location at different times and each electrode 8 generates an arc, enabling highly efficient, high-speed welding. Two welding torches 3 are arranged side by side in the traveling direction of carriage 4. Therefore, as carriage 4 travels along the weld line of workpieces W, one electrode 8 passes a welding location, and then the other electrode 8 passes the welding location later than the first electrode 8. Each electrode 8 melts the workpieces W, forming a single weld bead. Hereinafter, the leading electrode 8 that passes the welding location first may be referred to as electrode 8a, and the trailing electrode 8 that passes the welding location later than electrode 8a may be referred to as electrode 8b. Additionally, welding torch 3 that guides welding wire to be electrode 8a may be referred to as welding torch 3a, and welding power supply 2 that supplies power to electrode 8a may be referred to as welding power supply 2a. Additionally, welding torch 3 that guides welding wire to be electrode 8b may be referred to as welding torch 3b, and welding power supply 2 that supplies power to electrode 8b may be referred to as welding power supply 2b.

[0018] Welding power supply 2 converts AC power supplied from commercial power supply P into power suitable for welding and supplies it to welding torch 3 (electrode 8). In this embodiment, as shown in FIG. 1(a), welding power supply 2a supplies power to welding torch 3a (electrode 8a), and welding power supply 2b supplies power to welding torch 3b (electrode 8b). As shown in FIG. 1(b), welding power supply 2 includes rectifying and smoothing circuit 21, inverter circuit 22, transformer 23, rectifying and smoothing circuit 24, inverter circuit 25, current sensor 26, voltage sensor 27, first communication unit 29, second communication unit 20, and control circuit 28.

[0019] 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 in response 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. The rectifying and smoothing circuit 24 converts the high-frequency power input from the transformer 23 into DC power and outputs it.

[0020] Inverter circuit 25 converts the DC power input from rectifying and smoothing circuit 24 into AC power and outputs it by switching the switching elements in response to a switching drive signal input from control circuit 28. Inverter circuit 25 switches between EN (Electrode Negative), in which the potential of output terminal a (connected to workpiece W) is higher than the potential of output terminal b (connected to the contact tip of welding torch 3), and EP (Electrode Positive), in which the potential of output terminal a is lower than the potential of output terminal b. Note that welding power supply 2 may be a DC-only power supply that does not include inverter circuit 25.

[0021] 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 with output terminal a. The output current of welding power supply 2 detected by current sensor 26 is substantially equal to the current flowing through electrode 8. There are no limitations on the location where current sensor 26 is disposed. Current sensor 26 detects a current detection signal (analog signal) corresponding to the output current of welding power supply 2, and outputs the signal to control circuit 28.

[0022] Voltage sensor 27 detects the output voltage of welding power supply 2, and in this embodiment, detects the 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 detects a voltage detection signal (analog signal) corresponding to the output voltage of welding power supply 2 and outputs it to control circuit 28. Note that voltage sensor 27 may also detect the voltage between a lead wire conductively connected to the contact tip of welding torch 3 and a lead wire conductively connected to workpiece W.

[0023] The first communication unit 29 communicates with a first communication unit 11 (described later) of the control device 1 via the communication line 9. The first communication unit 29 and the first communication unit 11 perform digital communication, and in this embodiment, the communication is performed in accordance with the CAN (Controller Area Network) communication standard. The standard of communication between the first communication unit 29 and the first communication unit 11 is not limited and may be, for example, field bus communication or Ethernet communication. The first communication unit 29 and the first communication unit 11 may perform analog communication. The communication between the first communication unit 29 and the first communication unit 11 may be wireless communication that does not use the communication line 9. The first communication unit 29 receives a power output start command and a power output stop command from the control device 1 (first communication unit 11) and inputs the received command to the control circuit 28. The information that the first communication unit 29 receives from the control device 1 (first communication unit 11) is not limited. Furthermore, the first communication unit 29 transmits the detected current and voltage detected by the control circuit 28 to the control device 1 (first communication unit 11), as will be described later. Note that the information transmitted by the first communication unit 29 to the control device 1 (first communication unit 11) is not limited.

[0024] The second communication unit 20 communicates with a communication unit 62 (described later) of the management device 61 via a communication line 69. The second communication unit 20 and the communication unit 62 communicate digitally, and in this embodiment, they communicate in accordance with the Ethernet communication standard. The standard of communication between the second communication unit 20 and the communication unit 62 is not limited, and may be, for example, field bus communication or CAN communication. The second communication unit 20 and the communication unit 62 may also communicate analogically. Communication between the second communication unit 20 and the communication unit 62 may be wireless communication without using the communication line 69. The second communication unit 20 transmits the detected current and detected voltage detected by the control circuit 28 to the management device 61 (communication unit 62). The second communication unit 20 also transmits the set voltage of the output voltage and the set current of the output current of the welding power supply 2, which are set in the control circuit 28, to the management device 61 (communication unit 62). The information transmitted by the second communication unit 20 to the management device 61 (communication unit 62) is not limited. Furthermore, there are no limitations on the information that second communication unit 20 receives from management device 61 (communication unit 62). Welding power supply 2 may not include second communication unit 20, and first communication unit 29 may communicate with management device 61 (communication unit 62).

[0025] Control circuit 28 is a circuit for controlling welding power supply 2, and is realized by, for example, a microcomputer. Control circuit 28 controls the driving and stopping of inverter circuits 22, 25 based on an output start command and an output stop command received from control device 1 (first communication unit 11) via first communication unit 29. Specifically, control circuit 28 starts outputting a drive signal to inverter circuits 22, 25 when it receives an output start command, and stops outputting the drive signal when it receives an output stop command.

[0026] Control circuit 28 detects the output current value, which is a digital signal, based on the current detection signal input from current sensor 26. The output current value is the instantaneous value of the output current, obtained by converting the current detection signal (analog signal) into a digital signal. The output current value may be the absolute value of the instantaneous value of the output current, or may be an effective value or an average value. Control circuit 28 also detects the output voltage value, which is a digital signal, based on the voltage detection signal input from voltage sensor 27. The output voltage value is the instantaneous value of the output voltage, obtained by converting the voltage detection signal (analog signal) into a digital signal. The output voltage value may be the absolute value of the instantaneous value of the output voltage, or may be an effective value or an average value. Control circuit 28 transmits the detected output current value and output voltage value as detected current and detected voltage to control device 1 via first communication unit 29 and to management device 61 via second communication unit 20.

[0027] Control circuit 28 generates an output control drive signal to be output to inverter circuit 22 and a switching drive signal to be output to inverter circuit 25 according to the detected output current value, output voltage value, various setting values, etc. The configuration of welding power supply 2 is not limited.

[0028] Control device 1 performs various controls of welding system A1. Control device 1 includes a control board equipped with a microcomputer, a communication module, etc., an operation panel for operation, and a display panel for display. Control device 1 may be mounted on carriage 4 or may be located separately from carriage 4 (for example, adjacent to welding power supply 2). Control device 1 may also be a general-purpose computer with a program installed that performs various controls of welding system A1. Control device 1 controls the travel of carriage 4. Control device 1 instructs sprayer 7 to start and stop spraying flux 79. Note that sprayer 7 may start and stop spraying flux 79 manually. Control device 1 instructs each wire feeder 5 to start and stop feeding the welding wire and to set the welding wire feed speed. The feed speed is set according to the set welding current, etc. Control device 1 also communicates with each welding power supply 2 and controls each welding power supply 2. Control device 1 commands each welding power supply 2 to start and stop outputting power. Control device 1 also communicates with management device 61 and transmits welding-related information to management device 61. As shown in FIG. 1(b), control device 1 includes first communication unit 11, second communication unit 12, speed setting unit 13, and speed detection unit 14. Note that control device 1 also includes other components, but these are not shown in FIG. 1 and will not be described in detail.

[0029] The speed setting unit 13 sets the set speed of the travel speed of the carriage 4. The set speed is set depending on the material and thickness of the workpieces W. The set speed is preset in the speed setting unit 13 by an operator operating an operation panel. The speed setting unit 13 may also automatically set the set speed based on the material and thickness of the workpieces W. The speed detection unit 14 detects the detected speed, which is the actual travel speed of the carriage 4. The method for detecting the detected speed is not limited. The control device 1 drives a motor (not shown) to perform feedback control so that the detected speed becomes the set speed. The control device 1 may also perform feedforward control so that the travel speed of the carriage 4 becomes the set speed.

[0030] First communication unit 11 communicates with first communication unit 29 of each welding power supply 2 via communication line 9. First communication unit 11 transmits a power output start command and a power output stop command to each welding power supply 2 (first communication unit 29). The information that first communication unit 11 transmits to each welding power supply 2 (first communication unit 29) is not limited. First communication unit 11 receives detected current, detected voltage, etc. from each welding power supply 2 (first communication unit 29). The information that first communication unit 11 receives from each welding power supply 2 (first communication unit 29) is not limited.

[0031] The second communication unit 12 communicates with the communication unit 62 of the management device 61 via a communication line 69. The second communication unit 12 transmits the set speed set by the speed setting unit 13 and the detected speed detected by the speed detection unit 14 to the management device 61 (communication unit 62). The information that the second communication unit 12 transmits to the management device 61 (communication unit 62) is not limited. The information that the second communication unit 12 receives from the management device 61 (communication unit 62) is not limited. The control device 1 may not include the second communication unit 12, and the first communication unit 11 may communicate with the management device 61 (communication unit 62).

[0032] Management device 61 is a device that manages multiple welding power supplies 2. Management device 61 is realized by installing a management program on a general-purpose computer (for example, a notebook computer, a desktop computer, or a tablet terminal). The management program is provided in a state stored in a storage medium such as a USB memory. The management program may also be downloaded from a server via a communication line. Management device 61 may also be a dedicated device in which the management program is stored in advance on a computer.

[0033] In addition to welding power supplies 2a and 2b, many other welding power supplies are registered in management device 61. Management device 61 manages the operating status and error occurrences of each welding power supply. Management device 61 also acquires, records, and displays various information about each welding power supply. Management device 61 manages the welding power supplies by dividing them into multiple groups. Each welding power supply registered in management device 61 is associated with a group having a corresponding group number by the operator selecting the group number. The method for selecting the group number is not limited, and may be input in a dialog box or by selecting a check box. Each welding power supply may also be associated with a group by selecting the group number when registering it in management device 61. In this embodiment, a case will be described in which welding power supplies 2a and 2b are registered in a certain group, "Group 1." Management device 61 can manage the overall welding status of the welding power supplies belonging to each group.

[0034] In this embodiment, management device 61 manages the heat input for all welding operations in "group 1" by registering welding power supplies 2 (2a, 2b) that supply power to electrodes 8 in submerged arc welding using multiple electrodes 8 in "group 1." Management device 61 displays a list of the welding statuses of the welding power supplies that belong to the group, and also displays the heat input for all welding operations. Management device 61 includes a communication unit 62, a memory unit 63, a display unit 64, and a calculation unit 65.

[0035] Communication unit 62 communicates with second communication unit 20 of each welding power supply 2 via communication line 69. Communication unit 62 receives the detected current, detected voltage, set current, and set voltage from each welding power supply 2 (second communication unit 20). Note that the information that communication unit 62 receives from each welding power supply 2 (second communication unit 20) is not limited. Also, the information that communication unit 62 transmits to each welding power supply 2 (first communication unit 29) is not limited. Also, communication unit 62 communicates with second communication unit 12 of control device 1 via communication line 69. Communication unit 62 receives the set speed and detected speed from control device 1 (second communication unit 12). Note that the information that communication unit 62 receives from control device 1 (second communication unit 12) is not limited. Also, the information that communication unit 62 transmits to control device 1 (second communication unit 12) is not limited.

[0036] The calculation unit 65 calculates the heat input. The heat input is an approximate value obtained by converting the heat generated by the arc during welding and is expressed as the heat generated by the arc per unit length (J / cm). In submerged arc welding using multiple electrodes 8, the multiple electrodes 8 simultaneously weld to the workpiece W and apply heat, so the heat input must be calculated as the total heat generated by the arcs generated by the multiple electrodes 8. The calculation unit 65 calculates the effective current value Ia [A] using the detected current received from welding power supply 2a and calculates the effective voltage value Va [V] using the detected voltage. The calculation unit 65 also calculates the effective current value Ib [A] using the detected current received from welding power supply 2b and calculates the effective voltage value Vb [V] using the detected voltage. The calculation unit 65 also calculates the average speed v [cm / min] using the detected speed received from control device 1. Then, the calculation unit 65 calculates the heat input X [J / cm] from the effective current value Ia [A], the effective voltage value Va [V], the effective current value Ib [A], the effective voltage value Vb [V], and the average speed v [cm / min] based on the following equation (1). X=(Ia·Va+Ib·Vb)·60 / v ···· (1)

[0037] Memory unit 63 stores various information received by communication unit 62 and various information calculated by calculation unit 65. In this embodiment, memory unit 63 stores the detected current, detected voltage, set current, and set voltage received from each welding power supply 2, and the set speed and detected speed received from control device 1. Memory unit 63 also stores the heat input calculated by calculation unit 65. Note that the information stored in memory unit 63 is not limited, and it is not necessary to store all of the above information, or other information may be stored as well. The information stored in memory unit 63 can be used for calculations or displayed as a graph, according to instructions from the operator.

[0038] The display unit 64 is provided with a display means such as a liquid crystal display device, and performs various displays. The display unit 64 causes the display means to display an image generated based on the various information received by the communication unit 62 and the various information calculated by the calculation unit 65.

[0039] FIG. 2 is a diagram showing an example of a display screen 100 that the management device 61 causes the display means of the display unit 64 to display.

[0040] On the display screen 100, information on multiple welding power supplies is displayed by group, and tabs 101 for selecting a group are displayed. In this embodiment, for example, five groups are set. Note that the number of groups is merely an example and is not limited. The operator selects a desired group from the multiple tabs 101 by operating an operating means (not shown). For example, the operator operates a mouse to move the pointer so that it overlaps with the tab 101 representing the desired group, and then clicks to select it. Note that the operation method is not limited. In FIG. 2, the tab 101 representing "Group 1" is selected, and the statuses of the two welding power supplies 2 registered in "Group 1" are displayed. Note that in FIG. 2, welding power supply 2a is named "Power Supply 1," and welding power supply 2b is named "Power Supply 2," and the statuses of each are displayed in display frames 102. In the example of FIG. 2, five display frames 102 are arranged. Note that the number of display frames 102 to be arranged is not limited. Display frames 102 to which no welding power supplies are registered are indicated by dashed lines. The display mode of the display frame 102 may be changed depending on whether welding is being performed or not, or may also be changed when an abnormality occurs.

[0041] Each display frame 102 displays the RMS current value of the detected current, the RMS voltage value of the detected voltage, the set current, and the set voltage of the corresponding welding power supply 2. In the example of FIG. 2 , these are displayed numerically, but they may also be displayed together as a meter display, graph, or the like. These displays are based on the detected current, detected voltage, set current, and set voltage received from the welding power supply 2. The displayed items are not limited to those described above; for example, the wire feed speed may also be displayed. A heat input display frame 103 is located in the area of ​​the display area of ​​the tab 101 where no display frame 102 is located. The heat input display frame displays the heat input calculated by the calculation unit 65. The displayed heat input is the heat input from the most recent welding operation, but the operator may select to display the average or cumulative value of the heat input from past welding operations. The display area of ​​the tab 101 may also display information other than the heat input. For example, the set speed and detected speed of the carriage 4 may also be displayed. Note that the display screen 100 shown in FIG. 2 is an example, and the layout and display items of the display screen 100 are not limited.

[0042] Next, the operation and effects of the welding system A1 according to this embodiment will be described.

[0043] In this embodiment, calculation unit 65 of management device 61 performs calculations using information received from welding power supply 2a and information received from welding power supply 2b. Therefore, calculation unit 65 can perform calculations that take into account the influence of welding by welding power supply 2a and welding power supply 2b. This allows welding system A1 to manage the welding as a whole when multiple electrodes 8 are used for welding.

[0044] Furthermore, in this embodiment, calculation unit 65 of management device 61 calculates the overall heat input of welding to workpiece W using the detected current and voltage received from welding power supply 2a, the detected current and voltage received from welding power supply 2b, and the detection speed received from control device 1. This allows welding system A1 to calculate the overall heat input of welding using multiple electrodes 8. Therefore, the operator can quickly and easily check the heat input after welding is completed, making it easier to manage the welding results and reducing the amount of work required.

[0045] Furthermore, when the second communication unit 20 of the welding power supply 2 and the communication unit 62 of the management device 61 communicate digitally via the communication line 69, the welding system A1 can suppress communication failures caused by noise even in a noisy welding site.

[0046] In this embodiment, the case has been described where control device 1 transmits the set speed and detected speed of the travel speed of carriage 4 to management device 61, but this is not limited to this. The set speed and detected speed may be transmitted by control device 1 to welding power supply 2, and then welding power supply 2 may transmit them to management device 61 via second communication unit 20. In addition, if welding power supply 2 sets the set speed and detects the detected speed, welding power supply 2 may transmit them to management device 61.

[0047] In addition, in this embodiment, the case where the calculation unit 65 of the management device 61 calculates the heat input amount X based on the detected speed of the carriage 4 has been described, but this is not limiting. If the control device 1 does not detect the speed of the carriage 4, the management device 61 may calculate the heat input amount X using a set speed instead of the detected speed.

[0048] In addition, in this embodiment, the case where welding power supply 2 controls output using inverter circuit 22 has been described, but this is not limiting. Welding power supply 2 may also be configured to control output using a configuration other than an inverter circuit, such as a thyristor-controlled power supply or a moving-iron-core power supply.

[0049] In the present embodiment, welding system A1 has been described as a case in which wire feeder 5 feeds a welding wire and the tip portion of the welding wire protruding from the tip of welding torch 3 serves as electrode 8, but this is not limited to this. Welding system A1 may use an electrode made of non-melting material such as tungsten as electrode 8.

[0050] Second Embodiment FIG. 3 is a diagram illustrating a welding system A2 according to a second embodiment. FIG. 3(a) is a block diagram illustrating the internal configuration of multiple welding power supplies 2, a control device 1, and a management device 61. Note that the internal configuration of each welding power supply 2 is omitted in FIG. 3(a). FIG. 3(b) is a diagram illustrating a bead shape image generation unit 66 provided in a calculation unit 65 of the management device 61. Note that a block diagram showing the overall configuration of the welding system A2 is omitted because it is similar to FIG. 1(a). In FIG. 3, elements that are the same as or similar to those in the first embodiment are assigned 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 that it generates an estimated image of a bead shape.

[0051] Communication unit 62 of management device 61 according to this embodiment further receives the set EN ratio from each welding power supply 2. The EN ratio is the ratio of the EN period, and is obtained by dividing the EN period by the total period of the EN period and the EP period. The EN ratio is set in each welding power supply 2. Communication unit 62 also receives the set phase difference from welding power supply 2b that supplies power to trailing electrode 8b. The phase difference is the difference between the phase of the output current of welding power supply 2a and the phase of the output current of welding power supply 2b, and is set in welding power supply 2b.

[0052] Calculation unit 65 of management device 61 includes a bead shape image generation unit 66. Bead shape image generation unit 66 receives the detected current, detected voltage, and EN ratio (i.e., of the leading electrode) received from welding power supply 2a, the detected current, detected voltage, EN ratio, and phase difference (i.e., of the trailing electrode) received from welding power supply 2b, and the detected speed received from control device 1, and generates an estimated image of the bead shape. As shown in FIG. 3(b), in this embodiment, bead shape image generation unit 66 includes a welding mark parameter generation unit 661 and an image generation unit 662.

[0053] The welding mark parameter generator 661 receives input of the detection current, detection voltage, and EN ratio of the leading electrode, and the detection current, detection voltage, EN ratio, phase difference, and detection speed of the trailing electrode (hereinafter, these pieces of information may be collectively referred to as "welding information parameters"). Note that the welding information parameters input to the welding mark parameter generator 661 do not need to include all of the above, and may include other information. For example, the welding information parameters may include the material and thickness of the workpiece W, the material and diameter of the welding wire, and the like. The welding mark parameter generator 661 outputs welding mark parameters for generating a bead shape image. The welding mark parameters are parameters for indicating the shape of the so-called "scales," which are welding marks formed by a single arc generation. The appearance of the scales, including the clarity of the ripples, is formed depending on this single arc generation and the subsequent cooling time, etc. The weld bead is formed by the continuous formation of scales through repeated arc generation and cooling. The welding mark parameter generating unit 661 outputs, as the welding mark parameters, the size, spacing, and height of the scales, the clarity of the ripples, etc. Note that the welding mark parameters output by the welding mark parameter generating unit 661 do not have to include all of the above, and may include other information.

[0054] The welding mark parameter generation unit 661 generates welding mark parameters using artificial intelligence technology. In this embodiment, the welding mark parameter generation unit 661 has a welding mark neural network (hereinafter referred to as a "welding mark NN") as a trained model based on machine learning. The welding mark NN is a trained recurrent neural network having an input layer, multiple intermediate layers, and an output layer. The input layer includes multiple neurons to which welding information parameters are input. The output layer includes multiple neurons that output welding mark parameters. Note that the structure of the welding mark NN, such as the number of intermediate layers and the number of neurons in each layer, is not particularly limited. Furthermore, the welding mark NN is not limited to a recurrent neural network and may be configured using other types of neural networks. The welding mark NN undergoes pre-learning machine learning by providing a combination of welding information parameters and welding mark parameters measured from scales of weld beads formed by actual welding as training data to a pre-learning recurrent deep neural network. Furthermore, the welding mark NN undergoes further machine learning by a learning processing unit (not shown), thereby improving the accuracy of the generated parameters. The welding mark parameter generating unit 661 may be provided with artificial intelligence that performs machine learning other than the neural network.

[0055] Note that the welding mark parameter generating unit 661 may be configured without using artificial intelligence. For example, the welding mark parameter generating unit 661 may output welding mark parameters corresponding to input welding information parameters using a table or database that stores correspondence relationships between welding information parameters and welding mark parameters. The welding mark parameter generating unit 661 may also store an arithmetic expression for calculating the welding mark parameters from the welding information parameters, and output the welding mark parameters calculated by the arithmetic expression based on the input welding information parameters.

[0056] The image generation unit 662 generates an estimated image of the bead shape based on the welding mark parameters input from the welding mark parameter generation unit 661. Note that the bead shape image generation unit 66 may not include the welding mark parameter generation unit 661 and may be a so-called image generation AI that generates an estimated image of the bead shape based on the input welding information parameters. The calculation unit 65 of the management device 61 causes the display means of the display unit 64 to display the estimated image of the bead shape generated by the bead shape image generation unit 66 in response to an operation by the operator.

[0057] In this embodiment as well, calculation unit 65 of management device 61 performs calculations using information received from welding power supply 2a and information received from welding power supply 2b. Therefore, calculation unit 65 can perform calculations that take into account the influence of welding by welding power supply 2a and welding power supply 2b. This allows welding system A2 to manage the welding as a whole when multiple electrodes 8 are used for welding.

[0058] Furthermore, according to this embodiment, calculation unit 65 (bead shape image generation unit 66) of management device 61 generates an estimated image of the bead shape using the detected current, detected voltage, and EN ratio received from welding power supply 2a, the detected current, detected voltage, EN ratio, and phase difference received from welding power supply 2b, and the detected speed received from control device 1. This allows welding system A2 to generate and display an estimated image of the bead shape resulting from welding using multiple electrodes 8. Therefore, even if the weld bead is buried in flux 79 and cannot be seen, the operator can grasp the bead shape by looking at the estimated image. Furthermore, welding system A2 according to this embodiment has a configuration in common with welding system A1, and thereby achieves the same effects as welding system A1.

[0059] Third Embodiment FIG. 4 is a diagram illustrating a welding system A3 according to a third embodiment. FIG. 4(a) is a block diagram showing the overall configuration of the welding system A3. FIG. 4(b) is a block diagram showing the internal configuration of multiple welding power supplies 2, a control device 1, and a management device 61. Note that FIG. 4(b) omits the internal configuration of each welding power supply 2. In FIG. 4, elements that are the same as or similar to those in the first embodiment are assigned the same reference numerals as those in the first embodiment. The welding system A3 according to this embodiment differs from the welding system A1 according to the first embodiment in that it includes three electrodes 8.

[0060] In this embodiment, welding system A3 includes three welding power supplies 2, welding torches 3, wire feeders 5, wire reels 6, and electrodes 8. Hereinafter, the welding power supplies 2, welding torches 3, and electrodes 8 added to welding system A1 may be referred to as welding power supplies 2c, welding torches 3c, and electrodes 8c, respectively. Welding torch 3c is positioned alongside welding torches 3a and 3b, on the opposite side of welding torch 3b from welding torch 3a in the traveling direction of carriage 4. Welding torch 3c guides the welding wire that becomes electrode 8c. Therefore, due to the traveling of carriage 4, electrode 8c passes the welding point later than electrode 8b. Welding power supply 2c supplies power to electrode 8c. First communication unit 29 of welding power supply 2c communicates with first communication unit 11 of control device 1 via communication line 9. Second communication unit 20 of welding power supply 2c communicates with communication unit 62 of management device 61 via communication line 69.

[0061] In addition, in management device 61 according to this embodiment, welding power supply 2c is also registered in "Group 1." Communication unit 62 also communicates with second communication unit 20 of welding power supply 2c via communication line 69 to receive the detected current, detected voltage, set current, and set voltage. Calculation unit 65 calculates the effective current value Ic [A] using the detected current received from welding power supply 2c, and calculates the effective voltage value Vc [V] using the detected voltage. Calculation unit 65 then calculates the heat input amount X [J / cm] from the effective current value Ia [A], effective voltage value Va [V], effective current value Ib [A], effective voltage value Vb [V], effective current value Ic [A], effective voltage value Vc [V], and average speed v [cm / min] based on the following equation (2): X=(Ia·Va+Ib·Vb+Ic·Vc)·60 / V ···· (2)

[0062] In this embodiment, calculation unit 65 of management device 61 performs calculations using information received from welding power supply 2a, information received from welding power supply 2b, and information received from welding power supply 2c. Therefore, calculation unit 65 can perform calculations that take into account the influence of welding by welding power supply 2a, welding power supply 2b, and welding power supply 2c. This allows welding system A3 to manage welding as a whole when multiple electrodes 8 are used.

[0063] Furthermore, according to this embodiment, calculation unit 65 of management device 61 calculates the overall heat input of welding to workpiece W using the detected current and voltage received from welding power supplies 2a, 2b, and 2c, respectively, and the detected speed received from control device 1. This allows welding system A2 to calculate the overall heat input of welding using multiple electrodes 8. Furthermore, welding system A3 according to this embodiment has a common configuration with welding system A1, and thereby achieves the same effects as welding system A1.

[0064] In the first embodiment, a case where two electrodes 8 are provided has been described, and in the third embodiment, a case where three electrodes 8 are provided has been described. As can be understood from these descriptions, the welding system according to the present invention may be provided with four or more electrodes 8. Even in this case, the calculation unit 65 can calculate the heat input X [J / cm].

[0065] In the first to third embodiments, the welding systems A1 to A3 are described as performing submerged arc welding, but the present invention is not limited to this. The present invention can also be applied to welding systems that perform arc welding other than submerged arc welding, when multiple electrodes are used.

[0066] The arc welding system according to the present invention is not limited to the above-described embodiment, and the specific configuration of each part of the arc welding system according to the present invention can be freely designed and modified in various ways. [Explanation of symbols]

[0067] A1 to A3: welding system, 2, 2a, 2b, 2c: welding power supply, 4: carriage, 61: control device, 65: calculation unit, 8, 8a, 8b, 8c: electrodes, W: workpiece

Claims

1. a plurality of electrodes that melt to form a weld bead on the workpiece; a plurality of welding power supplies, each of which supplies power to one of the plurality of electrodes; a management device that receives information about welding from the plurality of welding power sources; Equipped with the plurality of welding power sources include a first welding power source and a second welding power source; the management device includes a calculation unit that performs calculations using the information received from the first welding power supply and the information received from the second welding power supply. Arc welding system.

2. The welding machine further includes a carriage on which the plurality of electrodes are mounted and which travels along the welding line. The arc welding system of claim 1 .

3. the management device receives the detected voltages and currents detected by the plurality of welding power supplies, The calculation unit calculates the amount of heat input to the workpieces using each detected voltage and each detected current and the traveling speed of the carriage. The arc welding system of claim 2 .

4. the management device receives the detected voltages and currents detected by the plurality of welding power supplies, the calculation unit generates an estimated image of the weld bead shape of the workpiece using each detected voltage and each detected current, the traveling speed of the carriage, the EN ratio of each welding power supply device, and the phase difference between each welding power supply device; The arc welding system of claim 2 .

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