Wire reel rotating device and welding system

Abstract

To reliably feed the wire to the welding torch with simple control. [Solution] A wire reel rotating device 1 used to supply wire W to a welding torch 3 comprises holding parts 11, 12, 14, 15, a drive unit 172, a detector 18, and a control unit 171. The holding parts 11, 12, 14, 15 rotatably hold a wire reel 9 on which the wire W is wound. The drive unit 172 rotates the wire reel 9. The detector 18 outputs a signal related to the amount of slack in the wire W. The control unit 171 receives the signal and controls the drive unit 172. The control unit 171 causes the drive unit 172 to rotate the wire reel 9 when the amount of slack in the wire W related to the signal is less than or equal to a predetermined amount.

Description

Technical Field

[0001] The present disclosure relates to a wire reel rotating device and a welding system, and more particularly relates to stably feeding a wire to a welding torch in arc welding.

Background Art

[0002] In arc welding, a wire feeding device that feeds a wire serving as a welding material to a welding torch is used. The wire feeding device pulls out the wire from a wire supply source by the force of a motor and supplies the wire to the welding torch.

[0003] When the wire feeding device pulls out the wire from the wire reel, the tension of the wire fluctuates due to the inertial force of the wire reel, which may make it difficult to stably supply the wire to the welding torch. Regarding suppressing the tension fluctuation of the wire and stably supplying the wire, Japanese Patent No. 7240544 (Patent Document 1) and Japanese Patent Laid-Open No. 2019-126821 (Patent Document 2) disclose a wire feeding device that is controlled such that the wire is loosened between a push feeder and a pull feeder.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] In a wire feeding system where the wire is controlled to slacken between a push feeder and a pull feeder, it is necessary to control the rotational speed of the push feeder and the rotational direction and speed of the pull feeder according to the amount of wire fed by the welding torch and the amount of wire slack. Generally, information output from the motor of the push feeder is used to drive the motor of the pull feeder. Therefore, means for acquiring information from each motor and means for controlling each motor are required, which can make the configuration of the wire feeding system complex.

[0006] This disclosure has been made in light of these circumstances, and its purpose is to stably feed the wire to the welding torch with simple control. [Means for solving the problem]

[0007] A wire reel rotating device according to an aspect of the present disclosure is a wire reel rotating device used for supplying wire to a welding torch, and comprises a holding unit, a drive unit, a detector, and a control unit. The holding unit rotatably holds a wire reel on which wire is wound. The drive unit rotates the wire reel. The detector outputs a signal related to the amount of wire slack. The control unit receives the signal and controls the drive unit. The control unit rotates the wire reel with the drive unit when the amount of wire slack related to the signal is less than or equal to a predetermined amount. [Effects of the Invention]

[0008] According to this disclosure, the wire can be stably fed to the welding torch with simple control. [Brief explanation of the drawing]

[0009] [Figure 1] This is a front view showing the schematic configuration of a welding system according to an embodiment. [Figure 2] This is a plan view showing the schematic configuration of a welding system according to an embodiment. [Figure 3] This is a rear perspective view of a wire reel rotating device according to an embodiment. [Figure 4] This figure shows the schematic configuration of a welding system related to a comparative example. [Figure 5] This figure shows a schematic configuration of the detector according to the embodiment. [Figure 6] This diagram illustrates a method for detecting wire slack in a detector according to an embodiment. [Figure 7] This figure shows a flowchart of the process for adjusting and controlling the amount of wire slack in a wire reel rotating device according to an embodiment. [Figure 8] This is a diagram illustrating the configuration of the detector in the modified example 1. [Figure 9] This diagram illustrates a method for detecting wire slack in a detector according to Modification 1. [Figure 10] This diagram illustrates a configuration for rotating a wire reel according to modified example 2. [Figure 11] This diagram illustrates the configuration for rotating the wire reel according to Modification 3. [Figure 12] This diagram illustrates the configuration for rotating the wire reel according to Modification 4. [Figure 13] This diagram illustrates a method for detecting wire slack in the detector according to Modified Example 5. [Modes for carrying out the invention]

[0010] The embodiments of this disclosure will be described in detail below with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and their descriptions will not be repeated.

[0011] [Overview of the welding system] FIG. 1 and FIG. 2 are diagrams schematically showing an example of the configuration of a welding system 100 provided with a wire reel rotation device 1 according to the present embodiment. The welding system 100 is used for arc welding, for example. The welding system 100 includes the wire reel rotation device 1, a wire feeding device 2, a welding torch 3, a robot arm 4, and a wire reel 9. When performing welding, the welding system 100 pulls out the wire W wound around the wire reel 9 attached to the wire reel rotation device 1 and feeds it to the welding torch 3. Hereinafter, a plane parallel to the base 11 included in the wire reel rotation device 1 is defined as an XY plane, the direction in which the wire W is fed out from the wire reel rotation device 1 is defined as an X-axis direction, and one direction orthogonal to the XY plane is defined as a Z-axis direction.

[0012] The wire reel rotation device 1 includes a base 11, a support post 12, a cap 13, a rotation shaft 14, a fixed shaft 15, a cover 16, a drive device 17, and a detector 18. The wire reel rotation device 1 rotates the wire reel 9 in accordance with the output of the detector 18, and suppresses fluctuations in the tension of the wire W between the wire reel 9 and the wire feeding device 2.

[0013] The base 11 has the other components of the wire reel rotation device 1 mounted thereon and supports these components. The base 11 is, for example, a flat steel plate.

[0014] The support post 12 is fixed to the upper surface of the base 11, and extends perpendicularly to the XY plane along the Z-axis direction. As shown in FIG. 2, the support post 12 is located on one side of the wire reel 9 in a plan view.

[0015] The cap 13 is screwed into the distal end portion of the rotation shaft 14. By attaching the cap 13, the wire reel 9 is fixed to the rotation shaft 14.

[0016] The fixed shaft 15 is fixed to the support post 12. The rotation shaft 14 is rotatably supported by the fixed shaft 15. The wire reel 9 is attached to the rotation shaft 14. The cover 16 is attached so as to cover the rotation shaft 14 on the side opposite to the mounting side of the wire reel 9 with the support post 12 as a boundary.

[0017] The drive unit 17 is configured to rotate the wire reel 9 fixed to the rotating shaft 14 by rotating the rotating shaft 14. The drive unit 17 comprises a control unit 171 and a motor 172. The control unit 171 controls the motor 172 based on a signal received from the detector 18 to rotate the rotating shaft 14. In this embodiment, the motor 172 is an electric motor, but is not limited to this. The motor 172 is an example of a "drive unit" in this disclosure.

[0018] The rotational drive of the wire reel 9 by the motor 172 of the drive unit 17 will be explained in more detail. Figure 3 is a rear perspective view of the wire reel rotating device 1. Note that in Figure 3, the control unit 171, detector 18, and wire W are omitted from the illustration.

[0019] Referring to Figure 3, the motor 172 is connected to the rotating shaft 14. In this embodiment, the motor 172 is an electric geared motor, and the rotational force of the motor is transmitted to the rotating shaft 14 via a reduction gear, causing the wire reel 9 to rotate.

[0020] The rotational speed of the wire reel 9 must be at least faster than the speed at which the wire feeder 2 feeds the wire W to the welding torch 3 during welding. Therefore, the rotational speed of the motor 172 may be constant at a speed faster than the speed at which the wire feeder 2 feeds the wire W to the welding torch 3, or it may be variably controlled according to the speed at which the wire feeder 2 feeds the wire W.

[0021] The configuration of the control unit 171 is not limited as long as it can receive signals output from the detector 18 and control the start and stop of the rotation of the rotating shaft 14 by the motor 172. For example, the control unit 171 is composed of an electrical circuit (hardware) that switches the voltage value or frequency supplied to the motor 172 according to the signal received from the detector 18. Alternatively, the control unit 171 may include a processor and memory and control the drive of the motor 172 by software processing.

[0022] In this embodiment, the drive unit 17 includes a control unit 171 and a motor 172, but the control unit 171 may be configured as a separate device from the drive unit 17.

[0023] Referring again to Figures 1 and 2, the detector 18 detects a signal related to the amount of slack in the wire W and outputs it to the control unit 171. The signal related to the amount of slack in the wire W may be the amount of slack in the wire W, the tension in the wire W, or the position of the wire W. Details of the detector 18 will be described later. The detector 18 and the control unit 171 may be connected by a wire or by wireless connection.

[0024] The welding torch 3 is attached to the tip of the robot arm 4. The wire W passes inside the welding torch 3, and a welding current is supplied by a power supply tip (not shown) located inside the nozzle 33. The wire W is melted by an arc discharge that occurs between it and the workpiece.

[0025] The robot arm 4 is a multi-jointed arm, for example, a 6-axis multi-jointed arm. The welding torch 3 is fixed to the tip of the robot arm 4. The robot arm 4 functions as a mobile device that moves the welding torch 3 at a set welding speed.

[0026] The wire reel 9 is the source of the wire W. The wire reel 9 has a winding section 91 and a pair of flanges 92, and the wire W is wound around the winding section 91. The wire reel 9 is also called a wire spool. The wire reel 9 is attached to the wire reel rotating device 1.

[0027] The winding section 91 is cylindrical. The wire W is wound along the outer circumferential surface of the winding section 91. The outer edges of the pair of flanges 92 extend radially outward from both ends in the axial direction of the winding section 91 and are located radially outward from the outer circumference of the wire W. Each outer edge of the flange 92 is circular.

[0028] The wire feeding device 2 feeds the wire W wound on the wire reel 9 to the welding torch 3. The wire feeding device 2 includes a housing 21, a base 22, a feeding roller 23, and a pressure roller 24.

[0029] The base 22 supports and mounts other components of the wire feeder 2. The base 22 is, for example, a flat steel plate. The base 22 is fixed, for example, in the same XY plane as the base 11.

[0030] The housing 21 houses the feed roller 23 and the pressure roller 24. In this embodiment, the feed roller 23 and the pressure roller 24 are housed in the housing 21, but the wire feeding device 2 may also have a configuration in which the feed roller 23 and the pressure roller 24 are enclosed in a frame.

[0031] The wire feeding device 2 includes a pair of feeding rollers 23 and pressure rollers 24 spaced apart in the wire feeding direction of the wire W. Each feeding roller 23 rotates in the same direction via a gear mechanism, for example, driven by a motor. Each pressure roller 24 is positioned above the corresponding feeding roller 23. Each pressure roller 24 rotates in accordance with the movement of the wire W, sandwiching the wire W between itself and each feeding roller 23.

[0032] During welding, the feed rollers 23 are driven by a motor, causing each of the feed rollers 23 to rotate and feed the wire W to the welding torch 3. The wire feeding speed is set appropriately according to the welding operation.

[0033] [Comparative Example] In arc welding, a wire feeder is used to supply the welding wire to the welding torch. The wire feeder uses a motor to draw the wire from the wire supply source and supply it to the welding torch.

[0034] Figure 4 shows a welding system 500 according to a comparative example. Unlike the wire reel rotating device 1 of the welding system 100 shown in Figures 1 and 2, the wire reel rotating device 5 of the welding system 500 does not have a drive device 17 and a detector 18.

[0035] In the welding system 500, during welding, a motor drives the feed rollers 23 of the wire feed device 2, causing each of the feed rollers 23 to rotate and feed the wire W to the welding torch. As the feed rollers 23 rotate, the wire reel 9 rotates and the wire W is pulled out. At this time, the tension of the wire W increases due to the inertia of the wire reel 9. This increase in wire W tension can make it difficult for the feed rollers 23 to stably feed the wire W to the welding torch 3. If the feeding of the wire W becomes unstable, the quality of the welding may decrease.

[0036] Patent documents 1 and 2 disclose wire feeding devices in which the wire is controlled to slacken between a push feeder and a pull feeder. In these wire feeding devices, it is necessary to control the rotational speed of the push feeder and the rotational direction and rotational speed of the pull feeder according to the amount of wire fed by the welding torch and the amount of wire slack. Generally, information output from the motor of the push feeder is used to drive the motor of the pull feeder. Therefore, means for acquiring information from each motor and means for controlling each motor are necessary, which can make the configuration of the wire feeding device complex.

[0037] [Welding system according to an embodiment] Therefore, the welding system 100 according to this embodiment uses a motor 172 to rotate the wire reel 9, thereby suppressing fluctuations in the tension of the wire W between the wire reel 9 and the wire feeding device 2. This allows the wire W to be stably fed to the welding torch 3 with simple control.

[0038] Specifically, the suppression of tension fluctuations in the wire W is achieved by rotating the wire reel 9 in accordance with the amount of slack in the wire W detected by the detector 18. This makes it possible to maintain a predetermined amount of slack in the wire W between the wire reel 9 and the wire feeding device 2, thereby reducing tension fluctuations in the wire W.

[0039] The following describes the process for adjusting the amount of slack in the wire W using the wire reel rotating device 1.

[0040] The wire reel rotating device 1 determines whether the amount of slack in the wire W is below a predetermined amount based on a signal related to the amount of slack in the wire W detected by the detector 18. If it determines that the amount of slack in the wire W is below a predetermined amount, the wire reel rotating device 1 rotates the wire reel 9.

[0041] Figures 5 and 6 illustrate the detection principle of wire W slack in the detector 18. Figure 5 shows the inside of the detector 18 when the wire W is not slack. Figure 6 shows the inside of the detector 18 when the wire W is slack.

[0042] Referring to Figures 5 and 6, the detector 18 comprises a housing 181, an inlet 182, an outlet 183, a cylinder 184, a potentiometer 185, and a stopper 186.

[0043] The housing 181 houses the cylinder 184, the potentiometer 185, the stopper 186, and a portion of the wire W. The housing 181 is provided with an inlet 182 through which the wire W is inserted from the outside of the housing 181 toward the inside of the housing 181, and an outlet 183 through which the wire W is led out from the inside of the housing 181 toward the outside of the housing 181. The inlet 182 is located below the outlet 183 in the Z-axis direction.

[0044] The inlet 182 has a pair of non-driven rollers 1821, and the outlet 183 has a pair of driven rollers 1831. The driven rollers 1831 drive the wire W in the direction of introducing it into the housing 181. The speed at which the driven rollers 1831 take in the wire W is at least slower than the speed at which the wire W is supplied from the wire reel rotating device 1. The wire W that has passed through the outlet 183 is drawn out to the wire feeding device 2.

[0045] The cylinder 184 is made of an insulating material. The wire W passes through the cylinder 184. A potentiometer 185 is mounted near the center of the cylinder 184. The resistance value of the potentiometer 185 changes according to the rotation angle of the cylinder 184. The control unit 171, which is connected to the potentiometer 185, detects the change in the resistance value of the potentiometer 185.

[0046] The reference position is defined as the point when the long axis of the cylinder 184 is parallel to the XY plane, and the resistance value of the potentiometer 185 at that time is defined as R0. The rotation angle of the cylinder 184 from this reference position is defined as θ, and the resistance value of the potentiometer 185 increases as θ increases. A stopper 186 is provided at a position corresponding to the position of the cylinder 184 when θ=0, so θ cannot be less than 0. The control unit 171 detects the resistance value R1 of the potentiometer 185. The resistance value R1 of the potentiometer 185 received by the control unit 171 is an example of a "signal related to the amount of slack in the wire W".

[0047] As shown in Figure 5, when there is no slack in the wire W, the cylinder 184 is pulled in the direction of the outlet 183 in the Z-axis direction relative to the wire W, and θ increases. Therefore, if ΔR = R1 - R0, ΔR increases as θ increases.

[0048] As shown in Figure 6, when the wire W is slack near the outlet 183, the force with which the wire W pulls up the cylinder 184 decreases, and one end of the cylinder 184 on the outlet 183 side is directed downward in the Z-axis direction due to gravity, so θ becomes smaller compared to the state in Figure 5. Therefore, ΔR decreases as the amount of slack in the wire W increases.

[0049] The control unit 171 compares the resistance value R1 of the potentiometer 185 received from the detector 18 with R0. Specifically, it determines whether the difference ΔR between R1 and R0 is greater than or equal to a predetermined threshold α. If ΔR is greater than or equal to the threshold α (ΔR≧α), the control unit 171 determines that the amount of slack in the wire W is small, drives the motor 172 to rotate the wire reel 9, and supplies the wire W into the detector 18. The value of the predetermined threshold α is determined in advance by, for example, the business operator or user providing the wire reel rotating device 1. In this embodiment, ΔR≧α is an example of "when the amount of wire slack is less than or equal to a predetermined amount".

[0050] As the wire reel 9 rotates, the wire W is supplied to the detector 18, and the amount of slack in the wire W increases. This reduces θ, and consequently reduces ΔR. The control unit 171 rotates the wire reel 9 to supply the wire W until ΔR < α.

[0051] With the control described above, if the amount of slack in the wire W within the detector 18 is less than or equal to a predetermined amount, the control unit 171 can rotate the wire reel 9 to supply wire W, thereby slackening the wire W. This suppresses fluctuations in the tension of the wire W between the wire reel 9 and the wire feeding device 2, allowing the wire feeding device 2 to stably feed the wire W to the welding torch 3.

[0052] [Flowchart for adjusting wire slack] Figure 7 is a flowchart illustrating an example of the process for adjusting the amount of wire slack by the wire reel rotating device 1. The process shown in Figure 7 is called and executed from the main routine when welding is started in the welding system 100, for example.

[0053] Referring to Figure 7, in step S12, the control unit 171 receives a signal from the detector 18 related to the amount of slack in the wire W. The signal related to the amount of slack in the wire W is, for example, the resistance value R1 of the potentiometer 185.

[0054] In step S14, the control unit 171 compares the magnitude of the resistance value R1 received in step S12 with the difference in magnitude ΔR between the resistance value R0 when the rotation angle of the cylinder 184 is 0 and the threshold α. If the control unit 171 determines that the difference ΔR between the resistance values ​​R1 and R0 is greater than or equal to the threshold α (ΔR = R1 - R0 ≥ α) (YES in step S14), it proceeds to step S16. Otherwise (NO in step S14), it terminates the process shown in Figure 7 and returns to the main routine. In step S16, the wire reel rotating device 1 rotates the wire reel 9 to supply the wire W to the detector 18. After that, the control unit 171 terminates the process shown in Figure 7 and returns to the main routine.

[0055] By controlling the wire reel according to the above process, the wire reel rotating device according to this disclosure can maintain a predetermined amount of wire slack during welding, thereby suppressing fluctuations in wire tension when the wire is pulled out from the wire reel. This enables stable feeding of the wire to the welding torch during arc welding.

[0056] Furthermore, since fluctuations in wire tension are suppressed according to the wire reel rotating device of this disclosure, the force required to pull out the wire in the wire feeding device can be reduced. In other words, the motor of the wire feeding device can be made smaller.

[0057] [Example 1] In the embodiments described above, an example was described in which the detector 18 includes a potentiometer 185. In the wire reel rotating device according to the present disclosure, the signal related to the amount of wire slack is not limited to the resistance value of the potentiometer, but may be output by, for example, a microswitch.

[0058] Figures 8 and 9 show a schematic configuration of the detector 18A according to Modification 1. The detector 18A has a housing 181, an inlet 182, an outlet 183, a cylinder 184, and a microswitch 187. One end of the cylinder 184 is supported by a rotation axis P, and the cylinder 184 can rotate on the XZ plane about the rotation axis P.

[0059] As shown in Figure 8, when there is no slack in the wire W, the cylinder 184 is pulled in the direction of the outlet 183 in the Z-axis direction relative to the wire W, and the cylinder 184 moves away from the microswitch 187, opening the contacts and becoming non-conductive (off). On the other hand, when slack occurs in the wire W and the cylinder 184 comes into contact with the microswitch 187, the contacts close and become conductive (on). When the microswitch 187 is turned off, the control unit 171 determines that the amount of slack in the wire W is less than or equal to a predetermined amount, and rotates the wire reel 9 to supply the wire W between the wire reel 9 and the wire feeding device 2.

[0060] As shown in Figure 9, when the wire reel 9 is rotated, the wire W is supplied into the detector 18. When the wire W slackens and the microswitch 187 turns on, the control unit 171 determines that the amount of wire W slack is greater than a predetermined amount and stops the rotation of the wire reel 9.

[0061] The method for detecting the amount of slack in the wire W is not limited to the method using a potentiometer or a microswitch as described above. For example, the tension of the wire W may be measured using a tension meter. In addition, although the above embodiment described an example in which the amount of slack in the wire W is detected by a member that displaces in accordance with the amount of slack in the wire W coming into contact with a contact-type sensor, the amount of slack in the wire W may also be detected by a configuration in which the contact-type sensor comes into direct contact with the wire W.

[0062] Even with this configuration, a predetermined amount of wire slack can be maintained during welding, which suppresses fluctuations in wire tension when pulling the wire from the wire reel and allows for stable wire feeding to the welding torch during arc welding.

[0063] [Differentiation 2] In the above-described embodiment, an example was given in which the motor 172 is a geared motor, but the rotational force of the motor 172 may be transmitted to the rotating shaft 14 via a torque transmission member.

[0064] Figure 10 illustrates a wire reel rotating device having a configuration in which the rotational force of a motor is transmitted to a rotating shaft via a torque transmission member. As shown in Figure 10, the wire reel rotating device 1A has a belt 1721 as a torque transmission member, and the rotational force of the motor 172 is transmitted to the rotating shaft 14 via the belt 1721. Other examples of torque transmission members are, for example, chains and gears.

[0065] Even with this configuration, by rotating the wire reel in accordance with the amount of wire slack, fluctuations in wire tension when pulling the wire from the wire reel can be suppressed.

[0066] [Difference 3] In the embodiments described above, the wire reel rotating device 1 and the wire reel rotating device 1A are configured to rotate the wire reel by directly or indirectly rotating the rotation shaft 14 of the wire reel 9 using a motor 172. The method of rotating the wire reel in the wire reel rotating device according to the present disclosure is not limited thereto, and for example, the wire reel may be rotated by rotating a rotating body provided so as to be in contact with the outer ring of the wire reel using a motor.

[0067] Figure 11 is a diagram illustrating a wire reel rotating device 1B according to modified example 3, the wire reel rotating device 1B includes a rotating body 1722.

[0068] The rotating body 1722 is connected to the motor 172 and rotates due to the rotational force transmitted from the motor 172. The rotating body 1722 is in contact with the outer edge of the flange 92 of the wire reel 9. When the rotating body 1722 rotates, the wire reel 9 rotates due to the frictional force between the rotating body 1722 and the wire reel 9. The rotating body 1722 is, for example, a rubber tire.

[0069] Even with this configuration, by rotating the wire reel in accordance with the amount of wire slack, fluctuations in wire tension when pulling the wire from the wire reel can be suppressed.

[0070] [Differentiation Example 4] In the embodiments described above, an example was explained in which the wire reel rotating device uses a motor to rotate the wire reel. The wire reel rotating device according to this disclosure may have components other than a motor as long as it can rotate the wire reel.

[0071] Figure 12 is a rear perspective view of the wire reel rotating device 1C according to modified example 4. In Figure 12, the control unit 171, detector 18, and wire W are omitted.

[0072] The wire reel rotating device 1C differs from the wire reel rotating device 1 in that it has a solenoid 1723, a linkage mechanism 1725, and a one-way clutch 1726. The one-way clutch 1726 has a mechanism that transmits rotation in only one direction and rotates freely in the reverse direction.

[0073] The solenoid 1723 has a plunger 1724. One end of the plunger 1724 is connected to one end of a link mechanism 1725. The link mechanism 1725 is a rod-shaped member, the other end of which is connected to the rotating shaft of a one-way clutch 1726.

[0074] The plunger 1724 moves linearly in the direction of arrow K in Figure 12 due to the magnetic field generated by the current flowing through the coil (not shown) of the solenoid 1723. Although not shown in Figure 12, the plunger 1724 is connected to an elastic body (spring) with one end connected to a bracket connected to the base 11. When the solenoid 1723 is driven and moves in the direction K, the elastic body stretches, applying an elastic force in the opposite direction to K. Therefore, when the current in the coil is interrupted and the magnetic field disappears, the plunger 1724 returns to its original position.

[0075] When current flows through the coil and the plunger 1724 moves in the K direction, the one-way clutch 1726 rotates via the link mechanism 1725. At this time, the one-way clutch 1726 rotates the axis of rotation of the wire reel 9 in the direction in which the wire W is pulled out from the wire reel 9. On the other hand, when the magnetic field disappears and the plunger 1724 returns to its original position, the one-way clutch 1726 rotates freely and the wire reel 9 does not rotate.

[0076] In the modified version 4, the control unit 171 repeatedly switches the state of the solenoid 1723 between energized and disconnected at predetermined intervals when rotating the wire reel 9. As a result, the plunger 1724 moves linearly back and forth. The force resulting from this linear motion is transmitted to the one-way clutch 1726 via the link mechanism 1725, causing the wire reel 9 to rotate.

[0077] Even when using this configuration of wire reel rotating device 1C, a predetermined amount of wire slack can be maintained during welding, thereby suppressing fluctuations in wire tension when pulling the wire from the wire reel, and enabling stable wire feeding to the welding torch during arc welding.

[0078] [Difference 5] In the above-described embodiment, the detector was described as measuring the amount of slack in the wire W by bringing the wire W into contact with a sensor via a cylinder 184, such as with a potentiometer 185 or a microswitch 187. However, the method for detecting the amount of slack in the wire W is not limited to a method that outputs a signal in response to contact with the wire W or a member that displaces according to the amount of slack in the wire W (for example, the cylinder 184), as described above.

[0079] Figure 13 shows a detector 18B that detects the amount of slack in the wire W using a non-contact sensor. The detector 18B includes a displacement sensor 188 located between the inlet 182 and outlet 183 inside the housing 181. The displacement sensor 188 measures the distance τ between the wire W and the displacement sensor 188 and outputs the distance τ information to the control unit 171. The displacement sensor 188 is, for example, an optical distance sensor.

[0080] When the slack in wire W is eliminated, wire W0 becomes wire W0, which is a straight line connecting the inlet 182 and the outlet 183. Let τ0 be the distance τ at this time.

[0081] As the amount of slack in the wire W decreases, the distance τ approaches the distance τ0 of a straight line connecting the inlet 182 and the outlet 183. As the amount of slack in the wire W increases, the distance τ moves away from the distance τ0.

[0082] The control unit 171 calculates the absolute value Δτ of the difference between the distance τ output by the displacement sensor 188 and the distance τ0. Δτ corresponds to the amount of slack in the wire W. The control unit 171 rotates the wire reel 9 when Δτ is less than or equal to a predetermined threshold β. This allows the wire W to slacken by the predetermined threshold β.

[0083] The non-contact sensor may be a laser sensor or an ultrasonic sensor. In addition, while the 5th modified example describes an example in which the distance between the wire W and the displacement sensor 188 is measured as the non-contact sensor, the non-contact sensor may also be an area sensor that determines whether or not the wire W is in a predetermined area.

[0084] [summary] (1) This disclosure relates to wire reel rotating devices 1, 1A, 1B, and 1C used to supply wire W to a welding torch 3. The wire reel rotating devices 1, 1A, 1B, and 1C include a holding unit (base 11, support column 12, rotating shaft 14, and fixed shaft 15) that rotatably holds a wire reel 9 on which the wire W is wound, a drive unit (motor 172, belt 1721, rotating body 1722, solenoid 1723, plunger 1724, link mechanism 1725, and one-way clutch 1726) that rotates the wire reel 9, detectors 18 and 18A that output signals related to the amount of slack in the wire W, and a control unit 171 that receives signals and controls the drive unit (motor 172, belt 1721, rotating body 1722, solenoid 1723, plunger 1724, link mechanism 1725, and one-way clutch 1726). The control unit 171 rotates the wire reel 9 using the drive unit (motor 172, belt 1721, rotating body 1722, solenoid 1723, plunger 1724, link mechanism 1725, and one-way clutch 1726) when the amount of slack in the signal-related wire W is less than or equal to a predetermined amount.

[0085] According to the wire reel rotating devices 1, 1A, 1B, and 1C of this disclosure, fluctuations in the tension of the wire W when pulling the wire W from the wire reel 9 can be suppressed. As a result, the wire feeding device 2 can stably feed the wire W to the welding torch 3. By stably supplying the wire W to the welding torch 3, the quality of welding can be improved.

[0086] (2) In the wire reel rotating devices 1, 1A, and 1C described in (1), the drive unit (motor 172, belt 1721) drives the rotating shaft 14 of the wire reel 9.

[0087] According to the wire reel rotating devices 1, 1A, and 1C of this disclosure, the drive unit drives the rotation shaft 14 of the wire reel 9, thereby allowing the wire reel 9 to rotate.

[0088] (3) In the wire reel rotating device 1B described in (1), the drive unit (motor 172, rotating body 1722) drives the outer ring of the wire reel 9.

[0089] According to the wire reel rotating device 1B of this disclosure, the wire reel can be rotated by the drive unit driving the outer ring of the wire reel 9.

[0090] (4) In the wire reel rotating device 1C described in (1), the drive unit (solenoid 1723, plunger 1724, link mechanism 1725, and one-way clutch 1726) includes a solenoid 1723 having a coil and a plunger 1724 configured to move linearly in response to the energization of the coil, a one-way clutch 1726 for rotating the wire reel 9, and a link mechanism 1725 having one end connected to the plunger 1724 and the other end connected to the rotation axis of the one-way clutch 1726, which converts linear motion into rotational motion of the one-way clutch 1726.

[0091] According to the wire reel rotating device 1C of this disclosure, the wire reel 9 can be rotated by the link mechanism 1725 converting the linear motion of the plunger 1724, which is caused by energizing the coil of the solenoid 1723, into the rotational motion of the one-way clutch 1726.

[0092] (5) In the wire reel rotating devices 1, 1A, 1B, 1C described in any of (1) to (4), the detectors 18, 18A include contact-type sensors (cylinder 184, potentiometer 185, stopper 186, microswitch 187).

[0093] According to the wire reel rotating devices 1, 1A, 1B, and 1C of this disclosure, the amount of slack in the wire W can be detected based on the signal output from the contact-type sensor.

[0094] (6) In the wire reel rotating devices 1, 1A, 1B, and 1C of (1), the detector 18B includes a non-contact type sensor (displacement sensor 188).

[0095] According to the wire reel rotating devices 1, 1A, 1B, and 1C of this disclosure, the amount of slack in the wire W can be detected based on a signal output from a non-contact sensor.

[0096] (7) This disclosure relates to a welding system. The welding system comprises a wire reel rotating device 1, 1A, 1B, 1C as described in any of (1) to (6), and a wire feeding device 2 that draws wire W from the wire reel rotating device 1, 1A, 1B, 1C and feeds the wire W toward a welding torch 3.

[0097] According to the welding system of this disclosure, fluctuations in the tension of the wire W when pulling the wire W from the wire reel 9 can be suppressed. As a result, the welding system can stably feed the wire W to the welding torch 3. By stably supplying the wire W to the welding torch 3, the welding quality can be improved.

[0098] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of this disclosure is indicated by the claims rather than by the description of the embodiments above, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Explanation of Symbols]

[0099] 1,1A,1B,1C Wire reel rotating device, 2 Wire feeding device, 9 Wire reel, 11,22 Base, 12 Support column, 13 Cap, 14 Rotating shaft, 15 Fixed shaft, 16 Cover, 17 Drive unit, 18,18A Detector, 21,181 Housing, 23 Feeding roller, 24 Pressure roller, 91 Winding section, 92 Flange, 100 Welding system, 171 Control unit, 172 Motor, 182 Inlet, 183 Outlet, 184 Cylinder, 185 Potentiometer, 186 Stopper, 187 Microswitch, 1721 Belt, 1722 Rotating body, 1723 Solenoid, 1724 Plunger, 1725 Link mechanism, 1726 One-way clutch, 1821 Drive roller, 1831 Roller.

Claims

1. A wire reel rotating device used to supply wire to a welding torch, A holding part that rotatably holds the wire reel on which the wire is wound, A drive unit for rotating the wire reel, A detector that outputs a signal related to the amount of slack in the wire, The system includes a control unit that receives the aforementioned signal and controls the drive unit, The control unit rotates the wire reel when the amount of slack in the wire related to the signal is less than or equal to a predetermined amount, and the control unit rotates the wire reel.

2. The wire reel rotating device according to claim 1, wherein the drive unit drives the rotation shaft of the wire reel.

3. The wire reel rotating device according to claim 1, wherein the drive unit drives the outer ring of the wire reel.

4. The aforementioned drive unit is A solenoid having a coil and a plunger configured to move linearly in response to the energization of the coil, A one-way clutch for rotating the wire reel, The wire reel rotating device according to claim 1, comprising a link mechanism having one end connected to the plunger and the other end connected to the rotating shaft of the one-way clutch, which converts the linear motion into rotational motion of the one-way clutch.

5. The wire reel rotating device according to any one of claims 1 to 4, wherein the detector includes a contact-type sensor.

6. The wire reel rotating device according to any one of claims 1 to 4, wherein the detector includes a non-contact type sensor.

7. A wire reel rotating device according to any one of claims 1 to 4, A welding system comprising a wire feeding device that pulls wire from the wire reel rotating device and feeds the wire toward a welding torch.

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