Wire feeding system and wire feeding method

Abstract

To provide a wire feeding system and a wire feeding method which can suppress service life of components such as a chip and a motor from being shortened.SOLUTION: A wire feeding system 1 comprises: a wire feeding part 10 that feeds a welding wire 4; a wire feeding control part 20 that controls the wire feeding part 10 so that forward feeding that feeds the welding wire 4 in a forward direction which is a direction of a base material or forward and reverse feeding that repeatedly feeds the welding wire 4 in the forward direction and in the reverse direction is performed; and a sensing part 30 that senses whether arc starts or not in slow-down control by which the welding wire 4 is fed in the forward direction in order to generate arc. The wire feeding control part 20, when the sensing part 30 senses that the arc does not start, controls the wire feeding part 10 so that the forward and reverse feeding is performed, while keeping on applying voltages for generating arc.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a wire feeding system and a wire feeding method. [Background technology]

[0002] Generally, when performing arc welding, slag is generated on the surface of the metal, and the slag may affect the finish of the welding or may hinder the generation of an arc. For this reason, when performing arc welding, the generated slag is removed.

[0003] Patent Document 1 discloses a technology in which, in a slag removal process, slag is removed by periodically repeating high-speed back and forth movements of a welding wire, and the slag removal process is terminated when a short circuit between the welding wire and the workpiece is detected by a short circuit monitoring unit. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5230600 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the technology disclosed in Patent Document 1, the repeated cyclical high-speed back and forth movement of the welding wire causes wear at the tip end and increases the load on the motor that moves the welding wire, resulting in a problem of shortening the lifespan of parts such as the tip and the motor.

[0006] Therefore, an object of the present invention is to provide a wire feeding system and a wire feeding method that reduce the shortening of the lifespan of components such as tips and motors. [Means for solving the problem]

[0007] A wire feeding system according to one aspect of the present invention includes a wire feeding unit that feeds a welding wire, a wire feeding control unit that controls the wire feeding unit to perform forward feeding, which feeds the welding wire in a forward direction that is the direction of a base material, or forward and reverse feeding, which feeds the welding wire repeatedly in the forward and reverse directions, and a detection unit that detects whether an arc has started during slow-down control in which the welding wire is forward fed to generate an arc. When the detection unit detects that an arc has not started, the wire feeding control unit controls the wire feeding unit to perform forward and reverse feeding while continuing to apply a voltage to generate an arc.

[0008] According to this aspect, when the detection unit detects that an arc has not started during slow-down control in which the welding wire is forwardly fed to generate an arc, the wire feed control unit controls the wire feed unit to feed the welding wire forward and backward while continuing to apply a voltage to generate an arc. This makes it possible to avoid excessive load on the motor caused by continuing the forward feeding of the welding wire and to avoid damage caused by strong contact between the tip and the base material. As a result, it is possible to reduce the shortening of the lifespan of parts such as the tip and the motor.

[0009] In the above aspect, when the wire feed control unit controls the wire feed unit to perform forward and reverse feed under slow-down control, the feed speed of the welding wire in the forward direction among the forward and reverse feeds may be greater than the feed speed of the welding wire in forward feed under slow-down control.

[0010] According to this aspect, in the slow-down control, the feeding speed of the welding wire in the forward direction among the forward and reverse feeds is greater than the feeding speed of the welding wire in the forward feed, so that slag, etc. adhering to the tip of the welding wire and slag, etc. present between the welding wire and the base metal can be appropriately removed.

[0011] In the above aspect, in the forward and reverse feed, the amount of welding wire fed in the forward direction may be equal to or greater than the amount of welding wire fed in the reverse direction.

[0012] According to this aspect, in the forward and reverse feed, the amount of welding wire fed in the forward direction is equal to or greater than the amount of welding wire fed in the reverse direction, so that the tip at the end of the welding wire repeatedly comes into contact with the base metal, and slag, etc. adhering to the end of the welding wire and slag, etc. present between the welding wire and the base metal can be appropriately removed.

[0013] In the above aspect, the wire feed control unit may control the wire feed unit to perform forward and reverse feed if an arc is not started within a predetermined time period after the slow-down control is started.

[0014] According to this aspect, if an arc does not start within a predetermined time after the slow-down control is started, forward and reverse feed of the welding wire is started, thereby preventing the forward feed of the welding wire from continuing and placing an excessive load on the tip, motor, etc.

[0015] In the above aspect, the predetermined time may be calculated based on at least one of a history of when an arc has started and a history of when an arc has not started.

[0016] According to this aspect, the predetermined time is calculated based on at least one of the history of when an arc was started and the history of when an arc was not started, so that forward and reverse feeding of the welding wire can be started at a more appropriate timing depending on the welding machine, each part of the wire feeding system, and the type and performance of the welding wire, etc. This makes it possible to more appropriately avoid placing an excessive load on the motor by continuing the forward feeding of the welding wire, and to avoid damage caused by strong contact between the tip and the base material. As a result, it is possible to reduce the shortening of the lifespan of parts such as the tip and the motor.

[0017] A wire feeding method according to one aspect of the present invention is a wire feeding method executed by a wire feeding system that feeds welding wire, and includes, in a slow-down control for feeding the welding wire to generate an arc, a forward feeding step of feeding the welding wire in a forward direction that is the direction of the base material, a detection step of detecting whether or not an arc has started in the forward feeding step, and, if it is detected in the detection step that an arc has not started, a forward / reverse feeding step of repeatedly feeding the welding wire in the forward and reverse directions while continuing to apply a voltage to generate an arc.

[0018] According to this aspect, in the slow-down control for feeding the welding wire to generate an arc, if it is detected in the detection step that an arc has not started, the welding wire is fed repeatedly in the forward and reverse directions in the forward and reverse feeding step while continuing the application of voltage to generate an arc. This makes it possible to avoid excessive load on the motor caused by continuing the forward feeding of the welding wire, and to avoid damage caused by strong contact between the tip and the base material. As a result, it is possible to reduce the shortening of the lifespan of parts such as the tip and the motor. Effect of the Invention

[0019] According to the present invention, it is possible to provide a wire feeding system and a wire feeding method that reduce the shortening of the lifespan of components such as tips and motors. [Brief description of the drawings]

[0020] [Figure 1] 1 is a block diagram illustrating a schematic configuration of a wire feeding system 1 according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a diagram showing how a welding wire 4 is fed and an arc is started in the wire feeding system 1 according to one embodiment of the present invention. [Diagram 3] 1 is a flowchart showing a wire feeding method M100 executed by a wire feeding system 1 according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. Note that the embodiment described below is merely a specific example for carrying out the present invention, and is not intended to limit the interpretation of the present invention. In addition, in order to facilitate understanding of the description, the same reference numerals are used as far as possible for the same components in each drawing, and duplicated descriptions may be omitted.

[0022] <One embodiment> [Wire feeding system configuration / function] 1 is a block diagram illustrating a schematic configuration of a wire feeding system 1 according to an embodiment of the present invention. The wire feeding system 1 is a system that feeds a welding wire 4 wound around a wire reel 2 to a welding torch 3 that performs arc welding. The wire feeding system 1 includes, for example, a wire feeding unit 10, a wire feeding control unit 20, and a detection unit 30. The wire feeding unit 10 includes a first wire feeding unit 11, a wire buffer 12, and a second wire feeding unit 13.

[0023] The first wire feeder 11 feeds the welding wire 4 wound around the wire reel 2 toward the welding torch 3. The first wire feeder 11 has, for example, a roller (not shown) that moves the welding wire 4 forward or backward, and a motor (not shown) that rotates the roller. The forward movement of the welding wire 4 means that the welding wire 4 moves toward the welding torch 3 (forward feed), and the backward movement of the welding wire 4 means that the welding wire 4 moves toward the wire reel 2 (reverse feed).

[0024] The motor rotates in a direction to advance or retreat welding wire 4 according to an instruction from wire feed control unit 20.

[0025] For example, during welding, first wire feeder 11 feeds welding wire 4 in an advancing direction in accordance with an instruction from wire feed control unit 20. Furthermore, during calibration, first wire feeder 11 moves welding wire 4 in an advancing direction or a retracting direction in accordance with an instruction from wire feed control unit 20.

[0026] The second wire feeder 13 feeds the welding wire 4 stored in the wire buffer 12 to the welding torch 3. The second wire feeder 13 has a roller and a motor, similar to the above-described first wire feeder 11. Details of the roller and the motor will be omitted.

[0027] For example, during welding, second wire feeder 13 feeds welding wire 4 to welding torch 3 while repeatedly moving welding wire 4 forward and backward at high speed relative to the base material (forward and reverse feed) in accordance with instructions from wire feed control unit 20. Furthermore, during calibration, second wire feeder 13 moves welding wire 4 in an forward or backward direction in accordance with instructions from wire feed control unit 20.

[0028] Wire buffer 12 is provided between first wire feeder 11 and second wire feeder 13, and absorbs the difference in the amount of welding wire 4 fed by first wire feeder 11 and second wire feeder 13. Wire buffer 12 enables welding wire 4 to be fed smoothly in either the forward or backward direction.

[0029] The wire feed control unit 20 is physically configured with, for example, a control unit including a processor, a memory, and a communication interface. The processor executes a predetermined program stored in the memory, so that the wire feed control unit 20 realizes a function of controlling the wire feeder 10 to feed the welding wire 4 in an advancing direction, a retreating direction, or alternately in an advancing direction and a retreating direction.

[0030] The detector 30 detects whether an arc starts during slow-down control in which the welding wire 4 is forwardly fed to generate an arc. For example, when performing welding, the welding torch 3 is moved to a welding start position and the welding wire 4 is fed, but the slow-down control is performed until an arc is generated. During the slow-down control, the welding wire 4 is fed at a speed slower than the feeding speed at which the welding wire 4 is fed during welding.

[0031] Usually, wire feed control unit 20 moves welding torch 3 to the welding start position, and controls wire feed unit 10 to feed welding wire 4 in the normal direction under slow-down control, and generates an arc by bringing the tip of welding wire 4 into contact with the base metal. Here, even though an arc should be generated if the tip of welding wire 4 is in normal contact with the base metal, there are cases where an arc does not actually start, and detection unit 30 detects that an arc has not started.

[0032] For example, the detection unit 30 detects whether an arc starts in slow-down control in which the welding wire 4 is forward-fed to generate an arc by monitoring the load of the motor. The welding wire 4 is fed by driving the motor, but if the tip of the welding wire 4 directly or indirectly contacts the base metal and feeding of the welding wire 4 is continued, the load on the motor increases. In other words, if an arc does not start even when the load of the motor reaches a threshold value, the detection unit 30 may detect that the tip of the welding wire 4 and the base metal are not in normal contact with each other, for example, because slag or the like is interposed between the tip of the welding wire 4 and the base metal, and thus the arc does not start in slow-down control in which the welding wire 4 is forward-fed to generate an arc.

[0033] Incidentally, to determine whether an arc has started, the detection unit 30 may typically detect a short circuit, which is an electrical contact between the welding wire 4 and the base metal. The detection unit 30 may be any device that can detect the start of an arc by detecting a short circuit between the welding wire 4 and the base metal, and may be realized, for example, by using a short circuit determination circuit that detects a voltage signal (voltage value, voltage waveform) or a current signal (current value, current waveform) to determine a short circuit.

[0034] The wire feed control unit 20 determines the feeding method of the welding wire 4 based on the detection status and detection result of the detection unit 30. For example, when the welding wire 4 is fed in the forward direction and the detection unit 30 detects that an arc has not started, the wire feed control unit 20 controls the wire feed unit 10 to perform forward and reverse feeding while continuing to apply a voltage for generating an arc. This will be described in detail below.

[0035] [Welding wire feed control in wire feed system] 2 is a diagram showing how the welding wire 4 is fed and an arc is started in the wire feeding system 1 according to one embodiment of the present invention. For example, when performing welding, the welding torch 3 is moved to a welding start position and the welding wire 4 is fed, but slow-down control is performed until an arc is generated.

[0036] 2, first, the welding wire 4 is fed from the welding torch 3 in the forward direction, which is the direction of the base material (forward feed). Specifically, the wire feed control unit 20 controls the wire feed unit 10 to feed the welding wire 4 in the forward direction from the welding torch 3. As described with reference to FIG. 1, the wire feed unit 10, in accordance with an instruction from the wire feed control unit 20, drives a motor that rotates a roller in a direction to advance the welding wire 4, thereby forward feeding the welding wire 4.

[0037] In the slow-down control, the tip of the welding wire 4, which is slowly fed in the direction of the base material, reaches the base material. If electrical contact (short circuit) occurs between the welding wire 4 and the base material at this point, an arc will be generated. However, there are cases where, for example, due to the influence of slag, etc., electrical contact (short circuit) does not occur between the welding wire 4 and the base material, and an arc is not generated.

[0038] In other words, it may appear that the tip of the welding wire 4 has reached the base material, but strictly speaking, due to reasons such as the presence of slag between the welding wire 4 and the base material, the detection unit 30, which is a short circuit determination circuit, may not detect that the welding wire 4 and the base material have made electrical contact (short circuit).

[0039] In this manner, in the slow-down control in which the welding wire 4 is forwardly fed to generate an arc, if the forward feeding of the welding wire 4 continues without starting an arc, the load on the motor will further increase.

[0040] Then, when the load on the motor increases and reaches a preset threshold, the welding wire 4 is fed from the welding torch 3 in a forward direction toward the base material and a reverse direction opposite thereto (forward and reverse feeding). Specifically, the wire feed control unit 20 controls the wire feed unit 10 to feed the welding wire 4 from the welding torch 3 in a forward and reverse direction repeatedly. As described with reference to FIG. 1, the wire feed unit 10 drives a motor that rotates a roller to feed the welding wire 4 forward and backward repeatedly according to an instruction from the wire feed control unit 20. At this time, the forward and reverse feeding of the welding wire 4 in the slowdown control is performed in a state where a voltage for generating an arc is continuously applied. The voltage for generating an arc is output by, for example, a welding power source unit (not shown) that may be included in the wire feeding system 1. The welding power source unit may be provided separately and distributed as a welding power source device.

[0041] As described above, the slow-down control is performed until an arc is generated, and therefore, even during this forward / reverse feed, the welding wire 4 is fed forward / reversely at a speed slower than the feed speed at which the welding wire 4 is fed during welding.

[0042] Here, the forward and reverse feed in the slow-down control will be described in detail. Forward and reverse feed is performed by repeating forward feed in a direction in which the welding wire 4 approaches the base metal (forward direction, forward advance) and reverse feed in a direction in which the welding wire 4 moves away from the base metal (reverse direction, backward), but the feed amount of the welding wire 4 in the forward feed and the feed amount of the welding wire 4 in the reverse feed are set to be the same.

[0043] If the feed rate of the welding wire 4 differs between forward feed and reverse feed, for example, if the feed rate of the welding wire 4 in reverse feed is greater than the feed rate of the welding wire 4 in forward feed, the distance between the tip of the welding wire 4 and the base metal increases. For this reason, there are cases where slag, etc. adhering to the tip of the welding wire 4 and slag, etc. present between the welding wire 4 and the base metal cannot be removed. In other words, slag, etc. that inhibits electrical contact between the welding wire 4 and the base metal cannot be removed, and an arc does not start.

[0044] Even if the vibration caused by forward and reverse feed can remove slag and the like adhering to the tip of the welding wire 4, the distance between the tip of the welding wire 4 and the base metal increases, and therefore the welding wire 4 and the base metal no longer come into physical contact during forward and reverse feed. As a result, no electrical contact (short circuit) occurs, and an arc does not start.

[0045] In addition, in forward and reverse feed, for example, if the welding wire 4 is fed forward and the tip of the welding wire 4 comes into contact with the base metal, the tip of the welding wire 4 presses the surface of the base metal. In this case, even if the feed amount of the welding wire 4 in forward feed and the feed amount of the welding wire 4 in reverse feed are set to be the same, the amount of movement in the reverse direction may actually be greater than the amount of movement in the forward direction. As a result, the distance between the tip of the welding wire 4 and the base metal increases in forward and reverse feed, so that the welding wire 4 and the base metal do not physically come into contact with each other in the forward and reverse feed. In other words, in order to appropriately bring the welding wire 4 into contact with the base metal in forward and reverse feed, it may be preferable to set the feed amount of the welding wire 4 in forward feed to be greater than the feed amount of the welding wire 4 in reverse feed.

[0046] When the feed amount of the welding wire 4 in forward feeding is larger than the feed amount of the welding wire 4 in reverse feeding, the welding wire 4 and the base metal are appropriately brought into contact with each other in forward and reverse feeding, and therefore the possibility of removing slag, etc., adhering to the tip of the welding wire 4 and slag, etc., present between the welding wire 4 and the base metal is improved. In forward and reverse feeding, the welding wire 4 is repeatedly brought into contact with the base metal, and for example, the slag, etc., adhering to the tip of the welding wire 4 and the slag, etc., adhering to the surface of the base metal are cracked and removed by the vibration and the impact of the contact. However, if the feed amount of the welding wire 4 in forward feeding is too large compared to the feed amount of the welding wire 4 in reverse feeding, the contact between the tip at the tip of the welding wire 4 and the base metal becomes strong, which may damage the tip and the base metal.

[0047] Therefore, in forward and reverse feed under the slow-down control, it is preferable that the feed amount of the welding wire 4 in forward feed and the feed amount of the welding wire 4 in reverse feed are set to be equal or nearly equal, and the feed amount of the welding wire 4 in forward feed is set to be equal to or greater than the feed amount of the welding wire 4 in reverse feed. That is, area A1 (reverse feed amount)≦area A2 (forward feed amount) and area B1 (reverse feed amount)≦area B2 (forward feed amount) shown in Fig. 2 are satisfied. This reduces the possibility of damaging the tip or base metal due to contact between the tip at the end of the welding wire 4 and the base metal, and improves the possibility of removing slag, etc. adhering to the end of the welding wire 4 and slag, etc. present between the welding wire 4 and the base metal.

[0048] As a result, electrical contact (short circuit) occurs between the welding wire 4 and the base material, generating an arc and performing welding.

[0049] Furthermore, in forward and reverse feeding under the slow-down control, it may be preferable that the feeding speed of the welding wire 4 in the forward direction during the forward and reverse feeding is higher than the feeding speed of the welding wire 4 in the forward feeding under the slow-down control. As described above, when an arc is not generated during forward feeding under the slow-down control, the welding wire 4 is controlled to be forward and reverse fed. At this time, by making the feeding speed of the welding wire 4 in the forward direction during forward and reverse feeding higher than the feeding speed during forward feeding, the possibility of properly removing slag, etc., adhering to the tip of the welding wire 4 and slag, etc., present between the welding wire 4 and the base metal is improved. As a result, by removing the cause of preventing the generation of an arc, electrical contact (short circuit) occurs between the welding wire 4 and the base metal, an arc is generated and welding is performed.

[0050] [Wire feeding method] Next, a wire feeding method executed by the wire feeding system 1 according to one embodiment of the present invention will be specifically described in detail.

[0051] 3 is a flowchart showing a wire feeding method M100 executed by the wire feeding system 1 according to one embodiment of the present invention. As shown in FIG 3, the wire feeding method M100 includes steps S101 to S104, and each step is executed by a processor included in the wire feeding system 1.

[0052] In step S101, the wire feeder 10 feeds the welding wire 4 in the forward direction toward the base material (forward feed step). Specifically, the wire feed control unit 20 controls the wire feeder 10 to forward feed the welding wire 4 in the slow-down control.

[0053] In step S102, if the welding wire 4 is fed in the normal direction under slow-down control in step S101 and the detection unit 30 detects the start of an arc (detection step), the process proceeds to step S104 (Yes in step S102), and if the start of an arc is not detected, the process proceeds to step S103 (No in step S102).

[0054] In step S103, the wire feeder 10 repeatedly feeds the welding wire 4 in the forward and reverse directions (forward and reverse feed step). Specifically, the wire feeder control unit 20 controls the wire feeder 10 in the slow-down control so as to feed the welding wire 4 in the forward and reverse directions while continuing to apply a voltage for generating an arc.

[0055] In step S104, welding is performed, and the wire feeding system 1 feeds the welding wire 4 in accordance with the welding. Specifically, the wire feed control unit 20 controls the wire feeder 10 to transition from the slow-down control to the welding control and feed the welding wire 4 at a faster speed than the feeding speed in the slow-down control.

[0056] Note that, here, in step S103, it is assumed that an arc is started by controlling wire feeder 10 to feed welding wire 4 in the forward and reverse directions, and the process proceeds to step S104, but more specifically, if the start of an arc is detected by feeding welding wire 4 in the forward and reverse directions, the process proceeds to step S104. For example, even if wire feeder 10 is controlled to feed welding wire 4 in the forward and reverse directions in step S103, if an arc does not start within a predetermined time, it may be assumed that an arc has not started, and a notification of an abnormality may be sent to the user.

[0057] As described above, according to the wire feeding system 1 and wire feeding method M100 of one embodiment of the present invention, in the slow-down control for forward feeding of the welding wire 4 to generate an arc, if the load on the motor reaches a threshold without starting an arc, the wire feed control unit 20 controls the wire feeder 10 to feed the welding wire 4 forward and backward while continuing to apply a voltage to generate an arc. This makes it possible to avoid excessive load on the motor and to avoid damage caused by strong contact between the tip and the base material. As a result, it is possible to reduce the shortening of the lifespan of components such as the tip and the motor.

[0058] In this embodiment, if an arc does not start even when the motor load reaches a threshold value, the detection unit 30 detects that an arc has not started, and the wire feed control unit 20 controls the wire feed unit 10 to feed the welding wire 4 forward and backward. However, the means by which the detection unit 30 detects that an arc has not started is not limited to this.

[0059] For example, based on the amount of welding wire 4 actually fed and the state of wire buffer 12 corresponding to a feeding command from wire feed control unit 20, detection unit 30 may detect that an arc has not started, and wire feed control unit 20 may control wire feed unit 10 to feed welding wire 4 in the forward and reverse directions.

[0060] More specifically, in the slow-down control in which the welding wire 4 is forward-fed to generate an arc, if the welding wire 4 continues to be forward-fed in response to a feed command from the wire feed control unit 20 without the arc being started, the tip of the welding wire 4 is already in direct or indirect contact with the base material, and therefore the amount of welding wire 4 fed does not actually reach the amount corresponding to the feed command, and the amount of welding wire 4 accommodated in the wire buffer 12 increases, resulting in an excess state. In this way, the detection unit 30 may detect that an arc has not been started based on the actual feed amount corresponding to the feed command and the excess state of the welding wire 4 in the wire buffer 12.

[0061] Furthermore, normally, when welding wire 4 is fed in the forward direction under slow-down control, electrical contact (short circuit) occurs between welding wire 4 and the base metal and an arc is started if no slag or the like is present between welding wire 4 and the base metal. Therefore, if detection unit 30 does not detect the start of an arc within a predetermined time period after the start of slow-down control, it may be determined that an arc has not started, and wire feed control unit 20 may control wire feed unit 10 to feed welding wire 4 in the forward and reverse directions.

[0062] Furthermore, the predetermined time may be calculated based on at least one of a history of when an arc was started and a history of when an arc was not started. For example, there may be variation in the time from when the welding wire 4 is forwardly fed under the slow-down control until the arc is started due to various factors such as the type and performance of the welding machine, the wire feeding system 1, the detection unit 30, the welding wire 4, and other factors such as the environment. For this reason, the time from when the welding wire 4 is forwardly fed under the slow-down control until the arc is started may be stored as history in a memory or the like, and the predetermined time may be set based on the history.

[0063] In addition, the detection unit 30 may use an optical sensor such as a CCD camera or a laser sensor to detect that the tip of the welding wire 4 has apparently reached the base material, and if an arc is not started even though an arc should be started, it may detect that an arc has not started.

[0064] In this embodiment, the wire feed control unit 20 and the detection unit 30 are arranged in the same housing as the wire feeder 10, and the wire feed system 1 shown in Fig. 1 can be regarded as one wire feeder, but is not limited to this. For example, all or a part of the wire feed control unit 20 and the detection unit 30 may be arranged in a housing (e.g., a control device) different from that of the wire feeder 10, and may be controlled by transmitting a feed command or the like to the wire feeder 10 via wire or wirelessly.

[0065] Furthermore, wire feed control unit 20 controls wire feeder 10 to feed welding wire 4 in the forward and reverse directions when welding wire 4 is forward fed in the slow-down control and an arc is not started, but the user may select whether to enable or disable the function associated with this control. The user may select enable or disable by operating a teaching pendant or the like, for example.

[0066] The above-described embodiments are intended to facilitate understanding of the present invention, and are not intended to limit the present invention. The elements of the embodiments, as well as their arrangements, materials, conditions, shapes, sizes, etc., are not limited to those shown as examples and can be changed as appropriate. In addition, configurations shown in different embodiments can be partially substituted or combined with each other. [Explanation of symbols]

[0067] 1...wire feeding system, 2...wire reel, 3...welding torch, 4...welding wire, 10...wire feeding section, 11...first wire feeding section, 12...wire buffer, 13...second wire feeding section, 20...wire feeding control section, 30...detection section, M100...wire feeding method, S101 to S104...each step of wire feeding method M100

Claims

1. A wire feeder that feeds a welding wire; a wire feed control unit that controls the wire feed unit to perform forward feeding, which feeds the welding wire in a forward direction that is a direction of a base material, or forward / reverse feeding, which feeds the welding wire repeatedly in the forward direction and a reverse direction; a detection unit that detects whether an arc is started during slow-down control of forward feeding of the welding wire to generate an arc, the wire feed control unit controls the wire feed unit to perform the forward / reverse feed while continuing to apply a voltage for generating the arc when the detection unit detects that an arc has not started, When the wire feeder is controlled by the wire feed control unit to perform the forward / reverse feed under slow-down control, a feed speed of the welding wire in the forward direction among the forward / reverse feeds is greater than a feed speed of the welding wire in the forward feed under slow-down control. Wire feeding system.

2. A wire feeding unit that feeds a welding wire; a wire feed control unit that controls the wire feed unit to perform forward feeding, which feeds the welding wire in a forward direction that is a direction of a base material, or forward / reverse feeding, which feeds the welding wire repeatedly in the forward direction and a reverse direction; a detection unit that detects whether an arc is started during slow-down control of forward feeding of the welding wire to generate an arc, the wire feed control unit controls the wire feed unit to perform the forward / reverse feed while continuing to apply a voltage for generating the arc when the detection unit detects that an arc has not started, In the forward and reverse feeding, the amount of welding wire fed in the forward direction is equal to or greater than the amount of welding wire fed in the reverse direction. Wire feeding system.

3. A wire feeding section that feeds a welding wire; a wire feed control unit that controls the wire feed unit to perform forward feeding, which feeds the welding wire in a forward direction that is a direction of a base material, or forward / reverse feeding, which feeds the welding wire repeatedly in the forward direction and a reverse direction; a detection unit that detects whether an arc is started during slow-down control of forward feeding of the welding wire to generate an arc, the wire feed control unit controls the wire feed unit to perform the forward / reverse feed while continuing to apply a voltage for generating the arc when the detection unit detects that an arc has not started, the wire feed control unit controls the wire feed unit to perform the forward / reverse feed when an arc is not started within a predetermined time period after the slow-down control is started, The predetermined time is calculated based on at least one of a history of when an arc has started and a history of when an arc has not started. Wire feeding system.

4. A wire feeding method performed by a wire feeding system that feeds a welding wire, comprising: a forward feeding step of feeding the welding wire in a forward direction, which is a direction of a base metal, in a slow-down control of feeding the welding wire to generate an arc; a detection step of detecting whether an arc starts during the positive feeding step; and a forward / reverse feeding step of feeding the welding wire repeatedly in the forward direction and the reverse direction while continuing application of a voltage for generating the arc when it is detected in the detection step that an arc has not been started, a feed speed of the welding wire in the forward direction when the welding wire is repeatedly fed in the forward and reverse directions in the forward and reverse feed step is greater than a feed speed of the welding wire in the forward direction in a slow-down control of the forward feed step. Wire feeding method.

5. A wire feeding method performed by a wire feeding system that feeds welding wire, comprising: a forward feeding step of feeding the welding wire in a forward direction, which is a direction of a base metal, in a slow-down control of feeding the welding wire to generate an arc; a detection step of detecting whether an arc starts during the positive feeding step; and a forward / reverse feeding step of feeding the welding wire repeatedly in the forward direction and the reverse direction while continuing application of a voltage for generating the arc when it is detected in the detection step that an arc has not been started, an amount of the welding wire fed in the forward direction when the welding wire is fed repeatedly in the forward and reverse directions in the forward and reverse feeding step is equal to or greater than an amount of the welding wire fed in the reverse direction; Wire feeding method.

6. A wire feeding method performed by a wire feeding system that feeds welding wire, comprising: a forward feeding step of feeding the welding wire in a forward direction, which is a direction of a base metal, in a slow-down control of feeding the welding wire to generate an arc; a detection step of detecting whether an arc starts during the positive feeding step; and a forward / reverse feeding step of feeding the welding wire repeatedly in the forward direction and the reverse direction while continuing application of a voltage for generating the arc when it is detected in the detection step that an arc has not been started, in the forward and reverse feeding step, if an arc is not started within a predetermined time period after the slow-down control is started, feeding of the welding wire in the forward and reverse directions repeatedly is started while continuing application of a voltage for generating the arc; The predetermined time is calculated based on at least one of a history of when an arc has started and a history of when an arc has not started. Wire feeding method.

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