Welding System

Abstract

To provide a welding system that can prevent deviation of the target position of a welding torch during welding work without having a complicated structure. [Solution] The welding robot (10) comprises a guide rail (21) arranged along a steel pipe (200), a welding robot (10) that welds the steel pipe (200) while moving on the guide rail (21) in a direction perpendicular to the longitudinal direction of the steel pipe (200), a welding cable (14c) that has one end connected to a welding torch (14) of the welding robot (10) and the other end connected to a device different from the welding robot (10), a fixing member (15) that fixes a fixed portion that is a portion between one end of the welding cable (14c) and the other end of the welding cable (14c) to the main body (11) of the welding robot (10), and a cable support member (40) that is arranged along the longitudinal direction of the steel pipe (200) and through which a portion between the fixed portion of the welding cable (14c) and the other end of the welding cable (14c) is positioned.

Description

[Technical Field]

[0001] The present invention relates to a welding system. [Background technology]

[0002] At construction sites, steel pipes that will become pillars are sometimes connected and welded in the axial direction. A structure has been disclosed in which a welding robot is moved along guide rails attached to the circumferential direction of the steel pipes while welding (for example, Patent Document 1). In addition, a structure has been disclosed in which a welding cable connected to a welding torch equipped on a welding robot is supported by a support arm, and the support arm is rotated by a cylinder to follow the welding torch (for example, Patent Document 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 6-91394 [Patent Document 2] Japanese Patent Application Laid-Open No. 2006-159230 Summary of the Invention [Problem to be solved by the invention]

[0004] In the structure shown in Patent Document 1, when the welding cable follows the movement of the welding robot, the welding cable is pulled by the welding robot. This can cause the tip of the welding torch connected to the welding cable to shift. As a result, the welding torch's target position may shift, and the welding quality may deteriorate. Furthermore, the structure shown in Patent Document 2 aims to solve the above-mentioned problems by allowing the welding cable to follow the welding robot without applying tension to it, but the device is large in size, which makes it unrealistic to use at construction sites.

[0005] The present invention has been made in consideration of the above-mentioned circumstances, and aims to provide a welding system that can prevent the target position of a welding torch from shifting during welding work without having a complex structure. [Means for solving the problem]

[0006] In order to solve the above problems, the present invention proposes the following means. The welding system of the present invention is characterized by comprising a guide rail arranged along a steel pipe, a welding robot that welds the steel pipe while moving on the guide rail in a direction perpendicular to the longitudinal direction of the steel pipe, a welding cable that is connected at one end to a welding torch of the welding robot and at the other end to a device different from the welding robot, a fixing member that fixes a fixed portion that is a portion of the welding cable between the one end and the other end of the welding cable to the main body of the welding robot, and a cable support member that is arranged along the longitudinal direction of the steel pipe and on which a portion of the welding cable between the fixed portion and the other end of the welding cable is positioned.

[0007] According to this invention, a fixing member is provided to fix the fixed portion of the welding cable to the main body of the welding robot. In other words, the fixing member fixes the welding cable to the welding robot. This prevents the portion of the welding cable between one end and the fixing member from moving relative to one another due to tension generated when the welding cable is pulled as the welding robot moves. This prevents the position and orientation of the welding torch connected to one end of the welding cable from shifting due to movement of the welding robot. This prevents the aim of the welding torch from shifting during welding work without requiring a complex structure.

[0008] Furthermore, during the above-described welding operation, the welding wire moves inside the welding cable. If the welding cable has a large curvature, the welding wire may warp significantly inside the welding cable. This may cause the welding wire to fail to reach the target position during the welding operation. In response to this, the welding system includes a cable support member on which the portion between the fixed portion of the welding cable and the other end of the welding cable is hung. This prevents excessive force from being applied to the welding cable when the welding robot moves. This prevents the welding cable from becoming too curvatured. This prevents the welding wire from becoming too warped, which can cause the target position during welding work to shift.

[0009] The cable support member may further include an elastic member having one end connected to the cable support member and the other end connected to the welding robot, and the cable support member may be rotatable around an axis corresponding to the longitudinal direction of the steel pipe.

[0010] According to this invention, the welding robot further includes an elastic member having one end connected to the cable support member and the other end connected to the welding robot. The cable support member is rotatable around an axis that is the longitudinal direction of the steel pipe. As a result, when the welding robot moves along the guide rail, the elastic member pulls the cable support member, causing the cable support member to rotate. This further reduces the tension generated in the welding cable as the welding robot moves. In other words, the welding torch is less likely to shift its target position during welding work, and the welding cable's curvature is prevented from increasing, more reliably preventing the wire from warping.

[0011] The welding robot may start welding from the opposite side of the cable support member across the steel pipe.

[0012] According to this invention, the welding robot starts welding from the opposite side of the cable support member across the steel pipe. Here, if the welding operation is started from the cable support member side, the length of the welding cable required for the welding robot to circle around the steel pipe during the welding operation is the length of the welding cable that is required to circle the steel pipe once. In contrast, by starting the welding work from the opposite side of the cable support member, the length of the welding cable required to go around the steel pipe can be the length from the side of the cable support member on the steel pipe to the opposite side of the cable support member. This allows the length of the welding cable required for welding work to be minimized. Furthermore, since the weight of the welding cable itself can be minimized, it is possible to prevent the welding cable from deforming under its own weight, which in turn prevents the welding wire moving inside from being deformed. Furthermore, by preventing the welding cable from becoming significantly loose, it is possible to prevent the welding cable from becoming tangled or from interfering with or coming into contact with surrounding equipment, workers, etc.

[0013] The system may further include an extension member fixed to the steel pipe or the guide rail, the extension member being a temperature measurement extension member for measuring the temperature of the steel pipe, and a temperature measurement cable connected to the temperature measurement extension member, and the temperature measurement cable may be attached along the upper ends of the guide rail and the cable support member.

[0014] According to this invention, the welding robot further includes a temperature measurement extension member and a temperature measurement cable, and the temperature measurement cable is attached along the upper ends of the guide rail and the welding cable support member. This prevents the welding cable and the temperature measurement cable from interfering with the movement range of the welding robot. This prevents the temperature measurement cable from pulling the welding cable, which could cause the welding torch to shift its target position, and prevents the welding cable from warping due to an increased curvature.

[0015] Furthermore, the cable installation method of the present invention is a cable installation method for a welding system comprising a guide rail arranged along a steel pipe, a welding robot that welds the steel pipe while moving on the guide rail, a welding cable connected to the welding robot, and a cable support member on which a portion of the welding cable is placed, wherein the welding system further comprises a temperature measurement extension member that is an extension member fixed to the steel pipe or the guide rail and is an extension member for measuring the temperature of the steel pipe, and a temperature measurement cable connected to the temperature measurement extension member, and the method for installing a welding cable and a temperature measurement cable in the welding system comprises a determination step of determining whether one of the cables included in the welding system is the welding cable or the temperature measurement cable, and an installation step of placing the cable determined to be the welding cable in the determination step on the cable support member, and placing the cable determined to be the temperature measurement cable in the determination step along the upper end of the guide rail and the cable support member.

[0016] According to this invention, the welding system includes a distinguishing step of distinguishing the cables included in the system and an installation step of arranging the identified cables. In the installation step, the welding cable is installed on the cable support member, and the temperature measurement cable is installed along the guide rail and the upper end of the cable support member. By distinguishing between the welding cable and the temperature measurement cable and installing them in different locations, it is possible to prevent the welding cable and the temperature measurement cable from interfering with each other and becoming entangled during welding work. This allows for safer work. [Effects of the Invention]

[0017] According to the present invention, which has been made in consideration of the above-mentioned circumstances, it is possible to provide a welding system that can prevent the target position of a welding torch from shifting during welding work without having a complex structure. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a perspective view showing a state in which a welding robot is positioned on a side where a cable support member is placed on a steel pipe in a welding system according to the present invention. FIG. [Figure 2] 2 is a perspective view showing a state in which a welding robot is positioned on the opposite side of a cable support member in the welding system shown in FIG. 1. FIG. [Figure 3] FIG. 2 is an overall view of the welding system in the state shown in FIG. [Figure 4] FIG. 3 is an overall view of the welding system in the state shown in FIG. 2. [Figure 5] FIG. 2 is an enlarged view of a welding robot in the welding system of the present invention. [Figure 6] 10 is a diagram showing a rotational range of a cable support member arranged on a steel pipe in a welding system according to the present invention. FIG. [Figure 7] 1A and 1B are diagrams showing a first example of a method for attaching a cable support member to a steel pipe in a welding system according to the present invention. [Figure 8] 10A and 10B are diagrams showing a second example of a method for attaching a cable support member to a steel pipe in a welding system according to the present invention. [Figure 9] 1 is a diagram showing a state in which a temperature measurement extension member and a temperature measurement cable are provided in a welding system according to the present invention. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0019] A welding system 100 according to one embodiment of the present invention will be described below with reference to the drawings. The welding system 100 shown in FIG. 1 includes a welding robot 10, a moving unit 20, an erection jig 30, a cable support member 40, and an elastic member 50. The welding system 100 is used, for example, when welding together axial ends of steel pipes 200 used as pillars at a construction site. That is, as shown in Fig. 1, the tip of a welding torch 14 (described later) of a welding robot 10 is placed against a groove 210 (described later) located at the location where the axial ends of the steel pipes 200 meet, and the welding robot 10 moves around the steel pipes 200 to weld the steel pipes 200.

[0020] When performing welding work on a steel pipe 200, the welding robot 10 welds the steel pipe 200 while moving on a guide rail 21 in a direction perpendicular to the axial direction of the steel pipe 200. The welding robot 10 includes a main body 11, a control unit 12, a control cable 12c, a robot control panel 12s, a slide unit 13, a welding torch 14, an arm 14a, a welding cable 14c, a wire feeder 14s, and a fixing member 15.

[0021] The main body 11 is a part that serves as a base for the welding robot 10. A servo motor (not shown) is built into the main body 11. This causes the welding robot 10 to move on guide rails 21 (described later). The control unit 12 is a part that controls the operation of the welding robot 10 in accordance with commands from a robot control panel 12s (described later). A control device (not shown) is built into the control unit 12. A control cable 12c is connected to the control unit 12. The main body 11 and the control unit 12 may be collectively referred to as the welding robot main body. A control cable 12c connects the control unit 12 and the robot control panel 12s. A known cable is preferably used as the control cable 12c.

[0022] The robot control panel 12s controls the operation of the welding robot 10. The robot control panel 12s is particularly responsible for rotating the servo motor in the main body 11 and issuing instructions for current load to the welding torch 14. The robot control panel 12s is connected to the control unit 12 via a control cable 12c.

[0023] The slide portion 13 is a portion of the welding robot 10 that is attached to the guide rail 21. The welding robot 10 moves in the circumferential direction of the steel pipe 200 as the slide portion 13 slides on the guide rail 21.

[0024] The welding torch 14 is a part where the steel pipes 200 are welded together. Arc welding is preferably used for welding with the welding torch 14. The steel pipes 200 are welded together by discharging electricity from the tip of the welding torch 14 toward a groove 210 of the steel pipe 200. Here, the groove 210 is the space between the ends of the steel pipes 200. As shown in Figures 3 and 4, the groove 210 is formed by cutting the end of one of the steel pipes 200 in an oblique shape. When the welding robot 10 is set up, it is set up so that the tip of the welding torch 14 is aligned with the groove 210 of the steel pipe 200 to be welded.

[0025] Arm portion 14a is provided between main body portion 11 and welding torch 14 and supports welding torch 14. Arm portion 14a may simply hold welding torch 14, or may have a mechanism that can change the orientation and angle of welding torch 14. More specifically, arm portion 14a may have a drive source and a mechanism that can change the orientation and angle in accordance with a control signal from control unit 12.

[0026] One end of welding cable 14c is connected to welding torch 14 of welding robot 10, and the other end is connected to a device (for example, wire feeder 14s, described below) different from welding robot 10. Welding cable 14c includes an electric wire for applying voltage to welding torch 14 and a supply line for supplying welding gas and welding wire to the welding portion. 3 and 4, one end of the welding cable 14c is connected to the welding torch 14. The other end is connected to the wire feeder 14s.

[0027] Wire feeder 14s supplies materials and voltage necessary for arc welding to welding torch 14. Wire feeder 14s includes a welding power source that applies the voltage used for arc welding, a gas cylinder that supplies gas to welding torch 14, and a wire feeder that supplies welding wire to welding torch 14. The gas cylinder is connected to, for example, the wire feeder. As a result, both gas and welding wire are supplied to welding torch 14 via supply lines. At the other end of the welding cable 14c, the supply line is connected to a wire feeder of the wire feeder 14s, and the electric wire is connected to a welding power source. In this embodiment, a known wire feeder is preferably used as the wire feeder 14s.

[0028] Fixing member 15 fixes a portion between one end of welding cable 14c and the other end of welding cable 14c to main body 11 of welding robot 10. Hereinafter, this portion may be referred to as a fixed portion. By gripping the fixed portion with the fixing member 15, even if the other end of the welding cable 14c is pulled further than the fixed portion as the welding robot 10 moves along the guide rail 21, the welding cable 14c between one end of the welding cable 14c and the fixed portion will no longer move relative to the main body 11. In this way, the fixing member 15 serves to prevent the welding torch 14, which is connected to one end of the welding cable 14c, from being pulled by the welding cable 14c and becoming displaced. As shown in Fig. 5, the fixing of the welding cable 14c by the fixing member 15 is preferably achieved by a known clamp. This makes it easy to attach and detach the welding cable 14c and to adjust the position of the fixed part.

[0029] The moving part 20 is a part along which the welding robot 10 moves. In this embodiment, the moving part 20 is provided around the steel pipe 200. The moving part 20 includes a guide rail 21 and an attachment part 22. The guide rail 21 is a portion that comes into contact with the slide portion 13 of the welding robot 10. The slide portion 13 of the welding robot 10 slides on the guide rail 21, causing the welding robot 10 to move on the guide rail 21. The guide rail 21 is arranged along the circumferential direction of the steel pipe 200. In other words, in this embodiment, the guide rail 21 is provided in a ring shape in the circumferential direction of the steel pipe 200. The guide rail 21 is attached to the steel pipe 200 by an attachment portion 22.

[0030] The mounting portion 22 is a portion that fixes the guide rail 21 to the steel pipe 200. The guide rail 21 and the mounting portion 22 may be welded together, or may be integrally formed, for example. For fixing the mounting portion 22 to the steel pipe 200, bolt fixing is preferably used, for example. The erection jig 30 is a member that temporarily holds the ends of the steel pipes 200 in a aligned state before welding. In other words, the erection jig 30 is removed after welding of the steel pipes 200 is completed. For example, bolt fastening is suitably used to fasten the erection jig 30 and the steel pipes 200 together.

[0031] The cable support member 40 is disposed along the longitudinal direction of the steel pipe 200. The cable support member 40 supports a portion of the welding cable 14c between the fixed portion and the other end of the welding cable 14c, and a portion of the control cable 12c. The cable support member 40 includes a cable hanger 41 and a cable hook F.

[0032] The cable hanger 41 is formed, for example, by combining members with L-shaped cross sections in a triangular shape. When the cable hanger 41 is arranged, as shown in FIG. 1, one side of the triangle is positioned close to but not in contact with the outer surface of the steel pipe 200 and is parallel to the axial direction of the steel pipe 200. In this case, for example, if the steel pipe 200 is a square prism, it is preferable to provide the cable hanger 41 at the center of one side of the square prism of the steel pipe 200, as shown in FIG. 1. By arranging it in this manner, the one side of the cable hanger 41 is connected in parallel to the rotation axis 42. In other words, the one side becomes the rotation center of the cable hanger 41 (described later).

[0033] The welding cable 14c and the control cable 12c are arranged on the cable hanger 41 as follows. That is, they are arranged so that they are hung on a cable hook F provided at the apex opposite to the one side of the triangle, that is, the apex located away from the steel pipe 200 as shown in FIG. 1. This allows the welding cable 14c and the control cable 12c to be positioned not on the floor at the work site but at least above the groove 210, which is the welded portion of the steel pipe 200. This prevents workers at the work site from tripping over the welding cable 14c and the control cable 12c or interfering with other equipment.

[0034] As shown in Fig. 7, the rotating shaft 42 is an axial (rod-like) member. The rotating shaft 42 extends parallel to the longitudinal direction of the steel pipe 200. The rotating shaft 42 rotatably supports the cable hanger 41. The cable hanger 41 supported by the rotating shaft 42 is arranged such that the one side of the cable hanger 41 is parallel to the rotating shaft 42. The cable hanger 41 is rotatable around the one side as the center of rotation. The rotating shaft 42 includes an outer cylinder 42o and a central shaft 42c. As shown in Fig. 7, the outer cylinder 42o is fixed to the steel pipe 200. The central shaft 42c is inserted into the outer cylinder 42o so as to be slidable in the circumferential direction. The upper end of the central shaft 42c is connected to the lower end of the one side of the cable hanger 41.

[0035] That is, the welding cable 14c and the control cable 12c arranged on the cable hook F can move within the movable range of the cable hanger 41 caused by the rotation shaft 42. As a result, when the welding robot 10 moves along the guide rail 21, the welding cable 14c and the control cable 12c connected to the welding robot 10 are pulled, causing the cable hanger 41 to move. By such a movement, the rotation shaft 42 enables the welding cable 14 c and the control cable 12 c arranged on the cable hanger 41 to follow the welding robot 10 .

[0036] The rotating shaft 42 is fixed along the steel pipe 200 and the guide rail 21 arranged on the steel pipe 200 as follows. That is, for example, first, as shown in FIG. 7, the lower end of the outer tube 42o is placed on a fixing base 42b arranged between the guide rail 21 and the steel pipe 200. Next, both side surfaces of the upper end of the outer tube 42o are held by magnets 42m magnetically attached to the steel pipe 200. The central shaft 42c, to which the cable hanger 41 is connected, is inserted into the outer tube 42o fixed in this manner to form the rotating shaft 42. Note that, as shown in FIG. 8, in addition to the above configuration, the fixing of the outer tube 42o may be reinforced by a binding wire 42w.

[0037] The above-mentioned fixed base 42b is arranged by, for example, fixing a block-shaped member to the annular inner peripheral surface of the guide rail 21 or the outer peripheral surface of the steel pipe 200. The fixing may be, for example, bolt fixing, or magnetic attachment by magnets 42m. Furthermore, well-known products are preferably used for the magnets 42m and binding wires 42w.

[0038] One end of the elastic member 50 is connected to the cable support member 40, and the other end is connected to the welding robot 10. Specifically, one end of the elastic member 50 connects the vertex of the cable hanger 41 of the cable support member 40, which is opposite to the side that contacts the steel pipe 200, to the main body 11 or the control unit 12 of the welding robot 10. Furthermore, the length of the elastic member 50 is preferably shorter than the length of the welding cable 14c and the control cable 12c from the portion arranged on the cable hanger 41 to the welding robot 10 (particularly, for the welding cable 14c, to the fixed member 15 of the welding robot 10). As a result, when the welding robot 10 moves along the guide rail 21, the elastic member 50 pulls the cable hanger 41, causing the cable hanger 41 to move. In other words, the elastic member 50 serves to prevent tension from being generated in the welding cable 14c and the control cable 12c connected to the welding robot 10. The elastic member 50 may be a metal spring or a rubber band.

[0039] Furthermore, as shown in FIG. 9, the welding system 100 may be provided with a temperature measurement extension member 60 and a temperature measurement cable 60c for measuring the outer surface temperature of the steel pipe 200 near the groove 210 before the start of welding work. The temperature measurement extension member 60 is an extension member fixed to the steel pipe 200 or the guide rail 21, and is used to measure the temperature of the steel pipe 200. In addition, a temperature measurement cable 60c is connected to the temperature measurement extension member 60. In addition, it is preferable that a temperature sensor 60s is disposed at the end of the temperature measurement cable 60c that is closer to the groove 210, and that one end of the temperature measurement extension member 60 is in contact with the steel pipe 200.

[0040] In this embodiment, the temperature measurement extension member 60 is preferably an elastic body. As a result, the temperature measurement extension member 60 biases the temperature sensor 60s in a direction perpendicular to the surface of the steel pipe 200 so that the temperature sensor 60s contacts the steel pipe 200. In other words, the temperature sensor 60s is pressed against the steel pipe 200 by the elasticity of the temperature measurement extension member 60. In this way, the temperature measurement extension member 60 plays a role in ensuring the accuracy of temperature measurement by the temperature sensor 60s by stably bringing the temperature sensor 60s into contact with the steel pipe 200.

[0041] The temperature measurement extension member 60 and the temperature measurement cable 60c having the above-described configuration are preferably attached along the upper ends of the guide rail 21 and the cable support member 40. Furthermore, as shown in Fig. 9, the temperature measurement extension member 60 and the temperature measurement cable 60c are preferably disposed between the guide rail 21 and the steel pipe 200 so as not to interfere with the movement range of the welding robot 10.

[0042] In this embodiment, the other end of the extension member for temperature measurement 60, i.e., the end opposite to the one end described above, is preferably attached to the guide rail 21. Here, as shown in FIG. 9 , the other end of the extension member for temperature measurement 60 is bent into a U-shape. The extension member for temperature measurement 60 is attached to the guide rail 21 as follows. That is, the extension member for temperature measurement 60 is fixed so as to sandwich the fixing metal fitting of the guide rail 21 through the U-shaped opening. Specifically, the part of the U-shape of the extension member for temperature measurement 60 that is closer to the other end when the U-shape is unfolded is inserted into a hole in the fixing metal fitting, and the part closer to one end is positioned outside the fixing metal fitting. In this way, the extension member for temperature measurement 60 is preferably fixed so that the U-shape of the extension member for temperature measurement 60 sandwiches the fixing metal fitting of the guide rail 21 due to the elastic force of the extension member for temperature measurement 60.

[0043] The welding process of the steel pipe 200 using the welding system 100 according to this embodiment is performed as follows. That is, with the tip of the welding torch 14 positioned in the groove 210, the welding robot 10 performs welding while moving along a guide rail 21 that is arranged in a ring shape around the steel pipe 200. Here, when the tip of the welding torch 14 moves along the groove 210, the welding torch 14 cannot move while positioned in the groove 210 at a location where the erection jig 30 is present. In this case, the arm unit 14a moves the welding torch 14 so as to avoid the erection jig 30. For a portion of the groove 210 that is straddled by the erection jig 30, the tip of the welding torch 14 is positioned by the arm unit 14a at an angle to avoid the erection jig 30. In this way, welding is performed without causing any discontinuities in the weld of the groove 210.

[0044] It is preferable that the welding operation by the welding robot 10 described above be started from the opposite side of the steel pipe 200 to the cable support member 40, i.e., from the state shown in Figures 2 and 4. Here, if the welding operation is started from the cable support member 40 side, i.e., from the state shown in Figures 1 and 3, the length of the welding cable 14c required for the welding robot 10 to circle the steel pipe 200 once during the welding operation is the length for one circle around the steel pipe 200. In contrast, it is preferable to start the welding work from the opposite side of the cable support member 40, so that the length of the welding cable 14c required to make one circuit around the steel pipe 200 is the length from the side of the cable support member 40 on the steel pipe 200 to the opposite side of the cable support member 40.

[0045] Next, a description will be given of a cable attachment method for the welding system 100 according to this embodiment. Note that, hereinafter, the welding cable 14c, the temperature measurement cable 60c, and the control cable 12c may be collectively referred to as cables.

[0046] (Discrimination process) This is a process for determining whether one of the cables included in the welding system 100 is the welding cable 14c, the temperature measurement cable 60c, or the control cable 12c. The determination may be made visually by an operator. Alternatively, if it is difficult to determine the cable by appearance alone, a barcode or the like may be attached to the outer surface of the cable and the barcode or the like may be read.

[0047] (Installation process) In this step, the cable that has been identified as the welding cable 14c or the control cable 12c in the identification step is placed in the cable hanger 41 of the cable support member 40. In addition, the cable that has been identified as the temperature measurement cable 60c in the identification step is placed along the guide rail 21 and the cable support member 40, particularly along the upper end of the cable hanger 41.

[0048] As described above, the temperature measurement cable 60c and the temperature measurement extension member 60 are provided between the steel pipe 200 and the guide rail 21, and do not move with the movement of the welding robot 10. In other words, unlike the welding cable 14c and the control cable 12c, there is no need for the temperature measurement cable 60c to follow the welding robot 10. For this reason, by arranging the temperature measurement cable 60c separately from the welding cable 14c, it is possible to prevent the welding cable 14c and the control cable 12c from interfering with and becoming tangled with the temperature measurement cable 60c during welding work, thereby ensuring safe work.

[0049] As described above, welding system 100 according to this embodiment includes fixing member 15 that fixes the fixed portion of welding cable 14c to main body 11 of welding robot 10. That is, welding cable 14c is fixed to welding robot 10 by fixing member 15. This prevents the portion of welding cable 14c between one end and fixing member 15 from moving relative to one another due to the tension generated when welding cable 14c is pulled as welding robot 10 moves. This prevents the position and orientation of welding torch 14 connected to one end of welding cable 14c from shifting due to movement of welding robot 10. This prevents the target position of welding torch 14 from shifting during welding work without requiring a complex structure.

[0050] Furthermore, during the above-described welding operation, the welding wire moves inside the welding cable 14c. If the curvature of the welding cable 14c is large, the welding wire may warp significantly inside the welding cable 14c. This may cause the welding wire to fail to reach the target position during the welding operation. In response to this, the welding system 100 includes a cable support member 40 on which the portion between the fixed portion of the welding cable 14c and the other end of the welding cable 14c is hung. This prevents excessive force from being applied to the welding cable 14c when the welding robot 10 moves. This prevents the curvature of the welding cable 14c from increasing. This prevents the target position during welding from shifting due to increased warping of the welding wire.

[0051] The welding robot 10 further includes an elastic member 50, one end of which is connected to the cable support member 40 and the other end of which is connected to the welding robot 10. The cable support member 40 is rotatable around an axis that is the longitudinal direction of the steel pipe 200. As a result, when the welding robot 10 moves along the guide rail 21, the elastic member 50 pulls the cable support member 40, causing the cable support member 40 to rotate. This further reduces the tension generated in the welding cable 14c as the welding robot 10 moves. In other words, this makes it more difficult for the welding torch 14 to shift its target position during welding work, and prevents the curvature of the welding cable 14c from increasing, more reliably preventing the wire from warping significantly.

[0052] Additionally, the welding operation by the welding robot 10 is started from the opposite side of the cable support member 40 across the steel pipe 200. Here, if the welding operation is started from the cable support member 40 side, the length of the welding cable 14c required for the welding robot 10 to circle the steel pipe 200 once during the welding operation is the length for one circle around the steel pipe 200. In contrast, by starting the welding operation from the opposite side of the cable support member 40, the length of the welding cable 14c required to make one circuit around the steel pipe 200 can be set to the length from the side of the cable support member 40 on the steel pipe 200 to the opposite side of the cable support member 40. This allows the length of the welding cable 14c required for the welding operation to be minimized. Furthermore, since the weight of the welding cable itself can be minimized, deformation of the welding cable 14c due to its own weight and deformation of the welding wire moving inside can be prevented. Furthermore, preventing the welding cable 14c from becoming significantly loose can prevent the welding cable 14c from becoming tangled or from interfering with or coming into contact with surrounding equipment, workers, etc.

[0053] The welding robot 10 further includes a temperature measurement extension member 60 and a temperature measurement cable 60c, and the temperature measurement cable 60c is attached along the upper end of the guide rail 21 and the welding cable support member. This prevents the movement range of the welding robot 10 from interfering with the welding cable and the temperature measurement cable 60c. This prevents the temperature measurement cable 60c from pulling the welding cable, which could cause the target position of the welding torch 14 to shift, and prevents the wire from warping due to an increase in the curvature of the welding cable 14c.

[0054] The welding system 100 also includes a distinguishing step of distinguishing the cables included therein, and an installation step of arranging the identified cables. In the installation step, the welding cable 14c is arranged on the cable support member 40, and the temperature measurement cable 60c is arranged along the guide rail 21 and the upper end of the cable support member 40. By distinguishing between the welding cable 14c and the temperature measurement cable 60c and arranging them in different locations in this way, it is possible to prevent the welding cable 14c and the temperature measurement cable 60c from interfering with each other and becoming entangled during welding work. This allows for safer work.

[0055] The technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, the rotation of the cable hanger 41 by the rotary shaft 42 may be controlled by a servo motor or the like. Furthermore, the cable support member 40 does not have to have the above-described configuration as long as the cable hanger 41 can be made movable. For example, a member having a structure equivalent to the above-described guide rail 21 may be attached to the steel pipe 200, and multiple attachment points for the welding cable 14c and the control cable 12c may be provided at intervals on the member.

[0056] In addition, within the scope of the spirit of the present invention, the components in the above-described embodiments may be replaced with well-known components as appropriate, and the above-described modifications may be combined as appropriate. [Explanation of symbols]

[0057] 10 Welding robot 11 Main body 14 Welding torch 14c welding cable 15 Fixing member 21 Guide rail 40 Cable support member 50 Elastic member 60 Temperature measuring extension member 60c Temperature Measurement Cable 100 Welding System 200 Steel pipe

Claims

1. a guide rail arranged along the steel pipe; a welding robot that welds the steel pipes while moving on the guide rail in a direction perpendicular to the longitudinal direction of the steel pipes; a welding cable having one end connected to a welding torch of the welding robot and the other end connected to a device different from the welding robot; a fixing member that fixes a fixed portion, which is a portion between the one end and the other end of the welding cable, to a main body of the welding robot and prevents the fixed portion from moving in the longitudinal direction of the welding cable; a cable support member disposed along the longitudinal direction of the steel pipe, on which a portion of the welding cable between the fixed portion and the other end of the welding cable is disposed; Equipped with A welding system comprising:

2. The welding operation by the welding robot is started from the opposite side of the cable support member across the steel pipe. The welding system of claim 1 .

3. The cable support member supports a portion of the control cable.

3. The welding system according to claim 1 or 2.

Images