Welding equipment

Abstract

To provide a welding apparatus excellent in portability, and capable of separately using automatic welding by a robot and semi-automatic welding by manual work with good workability.SOLUTION: A welding apparatus includes: a first direct-acting mechanism having a first base, and a first movable body movable to the first base; a second direct-acting mechanism having a second base detachably fixed to the first movable body, and a second movable body movable to the second base; a third direct-acting mechanism having a third base detachably fixed to the second movable body, and a third movable body movable to the third base; a holding body attached to the third movable body and detachably holding a welding torch for arc-welding; and a sensor attached to the third movable body and detecting a welding position. The first movable body and the second base have shapes to be positioned each other, the second movable body and the third base have shapes to be positioned each other, and the holding body and the welding torch have shapes to be positioned each other.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a welding apparatus.

Background Art

[0002] Conventionally, a welding apparatus typified by a welding robot that performs automatic welding by a robot has been known. For example, Patent Document 1 discloses a portable welding robot.

[0003] The welding robot described in Patent Document 1 includes a guide rail, a robot body that moves along the guide rail, and a torch connection part mounted on the robot body. The torch connection part includes a torch clamp that fixes the welding torch. The robot body is movable in a direction along the X-axis that moves along the guide rail, and the welding torch is movable in directions along each of the Y-axis and Z-axis perpendicular to the X-axis. Thereby, the welding torch moves in directions along each of the X-axis, Y-axis, and Z-axis.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The welding robot described in Patent Document 1 requires the entire robot to be transported as a single unit, making it difficult for one worker to transport. Furthermore, the welding robot described in Patent Document 1 assumes that the welding torch is fixedly installed at the torch connection point. Therefore, if manual semi-automatic welding is required in conjunction with the welding robot, a separate welding machine for manual operation must be prepared in addition to the welding robot. This increases equipment costs. Even if the welding torch were detachable from the torch connection point, aligning the welding torch with the connection point would take a long time, resulting in poor work efficiency.

[0006] In consideration of the above circumstances, one aspect of this disclosure aims to provide a welding apparatus that is highly portable and capable of efficiently switching between robotic automatic welding and manual semi-automatic welding. [Means for solving the problem]

[0007] To solve the above problems, a welding apparatus according to a preferred embodiment of the present disclosure comprises: a first linear motion mechanism having a first base and a first movable body that moves in a direction along a first axis relative to the first base; a second linear motion mechanism having a second base detachably fixed to the first movable body and a second movable body that moves in a direction along a second axis intersecting the first axis relative to the second base; a third linear motion mechanism having a third base detachably fixed to the second movable body and a third movable body that moves in a direction along a third axis intersecting the first and second axes relative to the third base; a holder attached to the third movable body for detachably holding a welding torch for arc welding; and a sensor unit attached to the third movable body for detecting the welding position, wherein the first movable body and the second base are shaped to be positioned relative to each other, the second movable body and the third base are shaped to be positioned relative to each other, and the holder and the welding torch are shaped to be positioned relative to each other. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic perspective view of a welding apparatus according to an embodiment. [Figure 2] This is a perspective view of the first linear motion mechanism. [Figure 3] This is a perspective view of the first linear motion mechanism. [Figure 4] This is a perspective view of the second linear motion mechanism. [Figure 5] This is a perspective view of the second linear motion mechanism. [Figure 6] This is a perspective view of the third linear motion mechanism. [Figure 7] This is a perspective view of the third linear motion mechanism. [Figure 8] This is a diagram illustrating the first positioning pin. [Figure 9] This is a perspective view of the holder and welding torch. [Figure 10] This is an exploded view of the holder. [Figure 11] This diagram illustrates the mounting state of the welding torch to the holder. [Figure 12] This is a front view of the sensor unit. [Figure 13] This is a diagram illustrating the space within the sensor unit. [Figure 14] This diagram shows the relationship between welding voltage, contact resistance, and weld bead shape. [Figure 15] This figure shows the relationship between conductance and dissolution depth. [Modes for carrying out the invention]

[0009] Preferred embodiments of the present disclosure will be described below with reference to the attached drawings. Note that the dimensions and scale of parts in the drawings may differ from actual dimensions as appropriate, and some parts are shown schematically for ease of understanding. Furthermore, the scope of the present disclosure is not limited to these embodiments unless otherwise stated in the following description.

[0010] 1. Embodiment 1-1. Overview of Welding Equipment FIG. 1 is a schematic perspective view of a welding apparatus 1 according to an embodiment. In FIG. 1, for the sake of clarity of the overview of the welding apparatus 1, the detailed illustration of the welding apparatus 1 is appropriately omitted, and the welding apparatus 1 is schematically shown.

[0011] First, the overview of the welding apparatus 1 will be described based on FIG. 1 below. The following description will be made using the X-axis, Y-axis, and Z-axis that are orthogonal to each other as appropriate for convenience. The X-axis is an example of the "first axis", the Z-axis is an example of the "second axis", and the Y-axis is an example of the "third axis". Hereinafter, one direction along the X-axis is the X1 direction, and the direction opposite to the X1 direction is the X2 direction. One direction along the Y-axis is the Y1 direction, and the direction opposite to the Y1 direction is the Y2 direction. One direction along the Z-axis is the Z1 direction, and the direction opposite to the Z1 direction is the Z2 direction. Typically, the Z-axis is the vertical axis, and the Z1 direction is vertically upward. Note that the intersection angle of the X-axis, Y-axis, and Z-axis is not limited to 90°, and may be within the range of 80° or more and 100° or less.

[0012] The welding apparatus 1 is a device that automatically performs arc welding on a workpiece W by a robot 2.

[0013] In the example shown in FIG. 1, the workpiece W is composed of two base materials Wa and Wb. Each of the base materials Wa and Wb is, for example, a steel plate such as stainless steel, mild steel, or carbon steel. The base materials Wa and Wb are arranged with their end faces abutted against each other at the welding position GR. The welding position GR extends along the X-axis.

[0014] Here, the workpiece W is constrained by the constraining jig 200. The constraining jig 200 has a plate-shaped base 210, four substantially inverted L-shaped constraining portions 220, and four wedges 230. The base 210 is installed such that the direction along the Z-axis is the thickness direction. A groove 211 extending along the X-axis is provided on the surface of the base 210 facing the Z1 direction, and the workpiece W is placed so that the welding position GR overlaps the groove 211. The four constraining portions 220 are arranged to surround the workpiece W on the base 210. Each of the four constraining portions 220 extends in the Z1 direction along the side surface of the workpiece W from the base 210 and has a portion located on the surface of the workpiece W facing the Z1 direction. The four wedges 230 correspond one-to-one to the four constraining portions 220. Each of the four wedges 230 is driven between the corresponding constraining portion 220 and the surface of the workpiece W facing the Z1 direction. Thereby, the workpiece W is constrained by the constraining jig 200.

[0015] Note that the configuration of the constraining jig 200 is not limited to the example shown in FIG. 1 and is arbitrary. Further, the constraining jig 200 is used as necessary and may be omitted.

[0016] As shown in FIG. 1, the welding apparatus 1 includes a first linear motion mechanism 10, a second linear motion mechanism 20, a third linear motion mechanism 30, a holder 40, and a sensor unit 50.

[0017] Here, the first linear motion mechanism 10, the second linear motion mechanism 20, and the third linear motion mechanism 30 constitute a robot 2 that can move the holder 40 and the sensor unit 50 in the directions along the X-axis, Y-axis, and Z-axis.

[0018] The first linear motion mechanism 10 supports the holder 40 and the sensor unit 50 via the second linear motion mechanism 20 and the third linear motion mechanism 30 in that order. The first linear motion mechanism 10 is a linear motion mechanism that moves the second linear motion mechanism 20 in the direction along the X axis. Therefore, the operation of the first linear motion mechanism 10 causes the holder 40 and the sensor unit 50 to move in the direction along the X axis. The second linear motion mechanism 20 is a linear motion mechanism that moves the third linear motion mechanism 30 in the direction along the Z axis. Therefore, the operation of the second linear motion mechanism 20 causes the holder 40 and the sensor unit 50 to move in the direction along the Z axis. The third linear motion mechanism 30 is a linear motion mechanism that moves the holder 40 and the sensor unit 50 in the direction along the Y axis. Therefore, the operation of the third linear motion mechanism 30 causes the holder 40 and the sensor unit 50 to move in the direction along the Y axis.

[0019] In the robot 2 described above, the first linear motion mechanism 10 and the second linear motion mechanism 20 are configured to be detachable from each other, and the second linear motion mechanism 20 and the third linear motion mechanism 30 are configured to be detachable from each other.

[0020] The holder 40 is a structure that detachably holds the welding torch 100. The welding torch 100 is a commercially available product that performs arc welding using, for example, an embedded arc. An "embedded arc" refers to an arc generated between the tip of the welding wire or the liquid column near the tip and the workpiece W when the tip of the welding wire is inserted into the space surrounded by the concave molten portion of the workpiece W. This concave shape is formed by the molten metal being pushed out by the arc force. The groove shape is not particularly limited and examples include X-shape, V-shape, U-shape, K-shape, I-shape, J-shape and H-shape.

[0021] The sensor unit 50 is an assembly having a sensor 52, described later, which detects the welding position GR.

[0022] In the welding apparatus 1 outlined above, the first linear motion mechanism 10, the second linear motion mechanism 20, and the third linear motion mechanism 30 are configured to be detachable from each other, allowing each linear motion mechanism to be transported individually. This provides excellent portability. Furthermore, since the holder 40 is detachable from the welding torch 100, not only can automatic welding be performed by a robot using these linear motion mechanisms, but also semi-automatic welding can be performed manually using the welding torch 100 removed from the holder 40. The parts of the welding apparatus 1 will be described in detail below.

[0023] 1-2. First Linear Motion Mechanism Figures 2 and 3 are perspective views of the first linear motion mechanism 10, respectively. Figures 2 and 3 show the first linear motion mechanism 10 viewed from different directions. As shown in Figures 2 and 3, the first linear motion mechanism 10 comprises a first base 11, a first movable body 12, a first rail 13, a first actuator 14, a first cover 15, two handles 16, and two legs 17. The parts of the first linear motion mechanism 10 will be described in order below based on Figures 2 and 3.

[0024] The first base 11 is a component that is installed in a fixed position relative to the workpiece W or the restraining fixture 200. The first base 11 is made of a metal such as iron, stainless steel, or aluminum alloy. In the examples shown in Figures 2 and 3, the first base 11 is plate-shaped, extending along the X-axis and having its thickness in the direction along the Z-axis.

[0025] The first movable body 12 is a member that moves in a direction along the X-axis relative to the first base 11. The first movable body 12 is made of a metal such as iron, stainless steel, or aluminum alloy. In the example shown in Figures 2 and 3, the first movable body 12 is plate-shaped with its thickness direction along the Z-axis and is supported by the first rail 13 via a linear bearing (not shown).

[0026] The surface of the first movable body 12 facing the Z1 direction is provided with two first positioning pins 12a and four screw holes 12b. Each of the two first positioning pins 12a is a projection that fits into the first positioning hole 21a of the second linear motion mechanism 20, which will be described later. Each of the four screw holes 12b is a female thread that fits into a screw (not shown) for fastening the second linear motion mechanism 20. Details of the first positioning pins 12a will be described later with reference to Figure 8.

[0027] The number, position, size, and other characteristics of the first positioning pins 12a are not limited to the examples shown in Figures 2 and 3. For example, the number of first positioning pins 12a may be three or more. Similarly, the number, position, size, and other characteristics of the screw holes 12b are not limited to the examples shown in Figures 2 and 3. For example, the number of screw holes 12b may be one to three, or five or more.

[0028] The first rail 13 is a linear rail that guides one of the first base 11 and the first movable body 12 to move relative to the other in a direction along the X-axis. In the example shown in Figures 2 and 3, the first rail 13 is fixed to the first base 11, and the first movable body 12 is attached to the first rail 13 via a linear bearing (not shown). This guides the first movable body 12 to move along the X-axis.

[0029] The first rail 13 may also be fixed to the first movable body 12. In this case, the first rail 13 is supported by the first base 11 via a linear bearing (not shown) and moves together with the first movable body 12 in a direction along the X axis.

[0030] The first actuator 14 is an electric motor such as a servo motor or pulse motor that generates a driving force to move one of the first base 11 and the first movable body 12 relative to the other in a direction along the X axis. The first actuator 14 is driven under the control of a control device (not shown). The control device controls the driving of the first actuator 14 based on the output of a linear encoder (not shown). The linear encoder outputs a signal corresponding to the position of the first movable body 12 in the direction along the X axis.

[0031] The first cover 15 is a component that protects the first rail 13 and the first actuator 14 from welding spatter. The first cover 15 is fixed to the first base 11 by screws or the like. In the example shown in Figures 2 and 3, the first cover 15 has a portion positioned in the Z1 direction relative to the first rail 13 and the first actuator 14, and a portion positioned in the Y2 direction. Here, the first rail 13 is positioned inside the first cover 15, while the first movable body 12 is positioned outside the first cover 15. The first cover 15 is provided with a pair of through holes 15a extending in the direction along the X axis. The first movable body 12 is guided to the first rail 13 through the pair of through holes 15a.

[0032] The material of the first cover 15 is not particularly limited, but from the viewpoint of preventing welding spatter from adhering, for example, aluminum or an aluminum alloy is preferably used. The first cover 15 may be formed integrally with the first base 11. The first cover 15 may also be provided or omitted as needed.

[0033] Each of the two handles 16 is a component for the worker to grip when transporting the first linear motion mechanism 10. In the examples shown in Figures 2 and 3, the handles 16 are roughly inverted U-shapes and are fixed to each end of the first base 11 in the width direction by screws or the like. The position, number, shape, and other aspects of the handles 16 are not limited to the examples shown in Figures 2 and 3 and are arbitrary. Also, the handles 16 may be provided as needed or omitted.

[0034] Each of the two legs 17 is a member that supports the first base 11. In the example shown in Figures 2 and 3, the legs 17 are fixed to each end of the first base 11 in the longitudinal direction by screws or the like, protruding from the first base 11 in the Z2 direction and having a longitudinal shape that extends in the direction along the Y axis. Each leg 17 is also provided with two height adjustment mechanisms 17a. The height adjustment mechanisms 17a are configured to be extendable and retractable in the direction along the Z axis, and fine adjustment of the posture of the first base 11 is made. The legs 17 may be formed integrally with the first base 11. The legs 17 may also be provided as needed or omitted.

[0035] 1-3. Second Linear Motion Mechanism Figures 4 and 5 are perspective views of the second linear motion mechanism 20. Figures 4 and 5 show the second linear motion mechanism 20 viewed from different directions. As shown in Figures 4 and 5, the second linear motion mechanism 20 comprises a second base 21, a second movable body 22, a second rail 23, a second actuator 24, a second cover 25, a handle 26, a side cover 27, and a top plate 28. The parts of the second linear motion mechanism 20 will be described in order below based on Figures 4 and 5.

[0036] The second base 21 is a member that is detachably fixed to the first movable body 12 of the first linear motion mechanism 10 described above. The second base 21 is made of a metal such as iron, stainless steel, or aluminum alloy. In the example shown in Figures 4 and 5, the second base 21 is plate-shaped with the direction along the Z-axis as the thickness direction.

[0037] Here, a side cover 27 extending in the direction along the Z axis is fixed to the Z1-facing surface of the second base 21 by screws or the like. A top plate 28 positioned in the Z1 direction relative to the second base 21 is fixed to the Z1-facing end of the side cover 27 by screws or the like. The side cover 27 and the top plate 28 are made of metal, such as iron, stainless steel, or aluminum alloy, similar to the second base 21. The side cover 27 and the top plate 28 may be formed integrally with each other, or they may be formed integrally with the second base 21.

[0038] The first movable body 12 of the first linear motion mechanism 10 is detachably fixed to the Z2-facing surface of the second base 21. More specifically, the Z2-facing surface of the second base 21 is provided with two first positioning holes 21a and four screw holes 21b. Each of the two first positioning holes 21a is a recess or through hole that fits onto the first positioning pin 12a of the first linear motion mechanism 10. A screw passes through each of the four screw holes 21b to fit into the screw hole 12b of the first linear motion mechanism 10. Here, from the viewpoint of improving workability, it is preferable that the screw is a wing nut or the like that can be tightened without tools.

[0039] The number, position, size, and other characteristics of the first positioning holes 21a are not limited to the examples shown in Figures 4 and 5. For example, the number of first positioning holes 21a may be three or more. Similarly, the number, position, size, and other characteristics of the screw holes 21b are not limited to the examples shown in Figures 4 and 5.

[0040] The second movable body 22 is a member that moves in a direction along the Z-axis relative to the second base 21. The second movable body 22 is made of a metal such as iron, stainless steel, or aluminum alloy. In the example shown in Figures 4 and 5, the second movable body 22 is plate-shaped with its thickness direction along the X-axis and is supported by the second rail 23 via a linear bearing (not shown).

[0041] The second movable body 22 has two second positioning pins 22a and two screw holes 22b on the surface facing the X1 direction. The second movable body 22 also has two screw holes 22b on the surface facing the Z1 direction. Each of the two second positioning pins 22a is a projection that fits into the second positioning hole 31a of the third linear motion mechanism 30, which will be described later. Although not shown, the second positioning pins 22a have the same shape as the first positioning pin 12a. Each of the four screw holes 22b is a female screw that fits into a screw (not shown) for fastening the third linear motion mechanism 30.

[0042] The number, position, size, and other characteristics of the second positioning pins 22a are not limited to the examples shown in Figures 4 and 5. For example, the number of second positioning pins 22a may be three or more. Similarly, the number, position, size, and other characteristics of the screw holes 22b are not limited to the examples shown in Figures 4 and 5. For example, the number of screw holes 22b may be one to three, or five or more.

[0043] The second rail 23 is a linear rail that guides one of the second base 21 and the second movable body 22 to move relative to the other in a direction along the Z-axis. In the example shown in Figures 4 and 5, the second rail 23 is fixed to the second base 21 via a second cover 25, and the second movable body 22 is attached to the second rail 23 via a linear bearing (not shown). This guides the second movable body 22 to move along the Z-axis.

[0044] The second rail 23 may also be fixed to the second movable body 22. In this case, the second rail 23 is supported by the second base 21 via a linear bearing (not shown) and moves together with the second movable body 22 in a direction along the Z axis.

[0045] The second actuator 24 is an electric motor such as a servo motor or pulse motor that generates a driving force to move one of the second base 21 and the second movable body 22 relative to the other in a direction along the Z-axis. The second actuator 24 is driven under the control of a control device (not shown). The control device controls the driving of the second actuator 24 based on the output of a linear encoder (not shown). The linear encoder outputs a signal corresponding to the position of the second movable body 22 in the direction along the Z-axis.

[0046] The second cover 25 is a component that protects the second actuator 24 from welding spatter. The second cover 25 is fixed to the second base 21 by screws or the like. In the example shown in Figures 4 and 5, the second cover 25 has a portion positioned in the X1 direction, a portion positioned in the X2 direction, and a portion positioned in the Y2 direction relative to the second actuator 24. Here, the second actuator 24 is positioned inside the second cover 25, while the second movable body 22 is positioned outside the second cover 25. The second cover 25 is provided with a through hole 25a extending in the direction along the Z axis. The second movable body 22 is connected to the second actuator 24 through the through hole 25a. In the illustrated example, the second cover 25 is composed of two components attached to the side cover 27.

[0047] The material of the second cover 25 is not particularly limited, but from the viewpoint of preventing welding spatter from adhering, for example, aluminum or an aluminum alloy is preferably used. The second cover 25 may be formed integrally with the second base 21 or the side cover 27. The second cover 25 may be provided as needed or omitted. The second cover 25 may also have a portion that covers the outside of the second rail 23.

[0048] The handle 26 is a component used by an operator to grip the second linear motion mechanism 20 when transporting it. In the examples shown in Figures 4 and 5, the handle 26 is roughly U-shaped and is fixed to the top plate 28 by screws or the like. The position, number, shape, and other aspects of the handle 26 are not limited to the examples shown in Figures 4 and 5 and are arbitrary. Furthermore, the handle 26 may be provided as needed or omitted.

[0049] 1-4. Third Linear Motion Mechanism Figures 6 and 7 are perspective views of the third linear motion mechanism 30, respectively. Figures 6 and 7 show the third linear motion mechanism 30 viewed from different directions. As shown in Figures 6 and 7, the third linear motion mechanism 30 comprises a third base 31, a third movable body 32, a third rail 33, a third actuator 34, a third cover 35, a pair of handles 36, and a support member 37. The parts of the third linear motion mechanism 30 will be described in order below based on Figures 6 and 7.

[0050] The third base 31 is a component that is detachably fixed to the second movable body 22 of the second linear motion mechanism 20 described above. The third base 31 is made of a metal such as iron, stainless steel, or aluminum alloy. In the example shown in Figures 6 and 7, the third base 31 is roughly plate-shaped with the thickness direction aligned with the X-axis. A holder 40 is fixed to the third base 31 by screws or the like. Details of the holder 40 will be described later with reference to Figures 9 to 11.

[0051] The second movable body 22 of the second linear motion mechanism 20 is detachably fixed to the surface of the third base 31 facing the X2 direction. More specifically, two second positioning holes 31a are provided on the surface of the third base 31 facing the X2 direction. Each of the two second positioning holes 31a is a recess or through hole that fits onto the second positioning pin 22a of the second linear motion mechanism 20. The third base 31 is also provided with four screw holes 31b. A screw passes through each of the four screw holes 31b to fit into the screw hole 22b of the second linear motion mechanism 20. Here, from the viewpoint of improving workability, it is preferable that the screw is a wing nut or the like that can be tightened without tools.

[0052] The number, position, size, and other characteristics of the second positioning holes 31a are not limited to the examples shown in Figures 6 and 7. For example, the number of second positioning holes 31a may be three or more. Similarly, the number, position, size, and other characteristics of the screw holes 31b are not limited to the examples shown in Figures 6 and 7. For example, the number of screw holes 31b may be one to three, or five or more.

[0053] The third movable body 32 is a member that moves in a direction along the Y-axis relative to the third base 31. The third movable body 32 is made of a metal such as iron, stainless steel, or aluminum alloy. In the example shown in Figures 6 and 7, the third movable body 32 is plate-shaped with its thickness direction along the Z-axis and moves along the third rail 33.

[0054] Here, a support member 37 is fixed to the surface of the third movable body 32 facing the Z1 direction by screws or the like. The support member 37 is plate-shaped, extending from the third movable body 32 in the Z1 direction and having its thickness direction along the X axis. The support member 37 is made of a metal such as iron, stainless steel, or aluminum alloy. The sensor unit 50 is fixed to the support member 37 by screws or the like. Details of the sensor unit 50 will be explained later with reference to Figures 12 and 13. Note that the position, size, shape, and other aspects of the support member 37 are not limited to the examples shown in Figures 6 and 7, but are arbitrary.

[0055] The third rail 33 is a linear rail that guides one of the third base 31 and the third movable body 32 to move relative to the other in a direction along the Y axis. In the example shown in Figures 6 and 7, the third rail 33 is fixed to the third base 31, and the third movable body 32 is attached to the third rail 33 via a linear bearing (not shown). This guides the third movable body 32 to move along the Y axis on the third rail 33.

[0056] The third rail 33 may also be fixed to the third movable body 32. In this case, the third rail 33 is supported by the third base 31 via a linear bearing (not shown) and moves together with the third movable body 32 in a direction along the Y axis.

[0057] The third actuator 34 is an electric motor such as a servo motor or pulse motor that generates a driving force to move one of the third base 31 and the third movable body 32 relative to the other in a direction along the Y axis. The third actuator 34 is driven under the control of a control device (not shown). The control device controls the driving of the third actuator 34 based on the output of a linear encoder (not shown). The linear encoder outputs a signal corresponding to the position of the third movable body 32 in the direction along the Y axis.

[0058] The third cover 35 is a component that protects the third rail 33 and the third actuator 34 from welding spatter. The third cover 35 is fixed to the third base 31 by screws or the like. In the example shown in Figures 6 and 7, the third cover 35 has a portion positioned in the X1 direction relative to the third actuator 34 and a portion positioned in the Y2 direction. Here, both the third rail 33 and the third actuator 34 are positioned inside the second cover 25.

[0059] The material of the third cover 35 is not particularly limited, but from the viewpoint of preventing welding spatter from adhering, for example, aluminum or an aluminum alloy is preferably used. The third cover 35 may be formed integrally with the third base 31. The third cover 35 may also be provided or omitted as needed.

[0060] Each of the pair of handles 36 is a component for the worker to grip when transporting the third linear motion mechanism 30. In the examples shown in Figures 6 and 7, the handles 36 are roughly inverted U-shapes and are fixed to the support member 37 by screws or the like. The position, number, shape, and other characteristics of the handles 36 are not limited to the examples shown in Figures 6 and 7 and are arbitrary. Also, the handles 36 may be provided as needed or omitted.

[0061] 1-5. Positioning pins Figure 8 is a diagram illustrating the first positioning pin 12a. The first positioning pin 12a will be described in a representative manner based on Figure 8. The explanation of the second positioning pin 22a will be omitted, but the relationship between the second positioning pin 22a and the second positioning hole 31a is the same as the relationship between the first positioning pin 12a and the first positioning hole 21a.

[0062] As shown in Figure 8, the first positioning pin 12a has a cylindrical portion 12a1 and a tapered portion 12a2 that protrudes from the tip of the cylindrical portion 12a1. The cylindrical portion 12a1 protrudes by a constant width from the surface of the first movable body 12 facing the Z1 direction. The tapered portion 12a2 protrudes from the end of the cylindrical portion 12a1 in the Z1 direction and has a truncated cone shape with a gradually decreasing width in the Z1 direction.

[0063] When the total length of the first positioning pin 12a is L, the length of the cylindrical portion 12a1 is La, and the length of the tapered portion 12a2 is Lb, it is preferable that the relationships L ≤ 10 mm and La ≤ 3 mm and 3 mm ≤ Lb ≤ (L - La) are satisfied.

[0064] By satisfying this relationship between lengths La and Lb, the workability of disassembling and assembling the first linear motion mechanism 10 and the second linear motion mechanism 20 can be improved. Conversely, if La is too long or Lb is too short, the assembly of these linear motion mechanisms tends to deteriorate depending on the shape of the positioning hole. On the other hand, if La is too short or Lb is too long, the positioning accuracy of these linear motion mechanisms tends to decrease depending on the shape of the positioning hole.

[0065] Here, from the viewpoint of improving the ease of attachment and detachment of the first positioning pin 12a and the first positioning hole 21a, the inclination angle θ1 of the tapered portion 12a2 with respect to the central axis is preferably 10° or more and 30° or less, and more preferably 15° or more and 25° or less.

[0066] Furthermore, the width W1 of the first positioning pin 12a is slightly smaller than the width W2 of the first positioning hole 21a. Here, from the viewpoint of ensuring the required positioning accuracy of the first linear motion mechanism 10 and the second linear motion mechanism 20, the difference between the widths W1 and W2 is preferably 0.2 mm or less, and more preferably 0.1 mm or less.

[0067] The configuration of the first positioning hole 21a is not limited to the example shown in Figure 8. For example, the first positioning hole 21a is not limited to a through hole, but may be a recess. In this case, the depth of the first positioning hole 21a is preferably greater than or equal to the length L of the first positioning pin 12a. The thickness of the second base 21 may also be greater than or equal to the length L of the first positioning pin 12a. Furthermore, the cross-sectional shape of the first positioning hole 21a may be the same as or similar to the cross-sectional shape of the first positioning pin 12a, or it may be a different shape from the cross-sectional shape of the first positioning pin 12a. In other words, the cross-sectional shape of the first positioning hole 21a is not limited to a circle, but may be an ellipse, a polygon such as a quadrilateral, for example.

[0068] 1-6.Holding body Figure 9 is a perspective view of the holder 40 and the welding torch 100. Figure 10 is an exploded view of the holder 40. As shown in Figure 9, the holder 40 holds the welding torch 100, which has a grip 110 for a person to hold. The holder 40 holds the grip 110 so as to wrap around it in the circumferential direction. The holder 40 has a first member 41, a second member 42, and a fastener 43.

[0069] The first member 41 is a plate-shaped member and is fixed to the aforementioned third movable body 32 by screws or the like. As shown in Figure 10, the first member 41 has a recess 41a that holds a first portion which is part of the grip 110. The recess 41a has a shape complementary to the first portion. Therefore, by housing the first portion of the grip 110 in the recess 41a, the wall surface of the recess 41a can be made to adhere to the surface of the first portion with substantially no gaps.

[0070] The second member 42 is a plate-shaped member and is placed on top of the first member 41. As shown in Figure 10, the second member 42 has a recess 42a that holds a second portion of the grip 110, which is a part different from the aforementioned first portion. The recess 42a has a shape complementary to the second portion. Therefore, by housing the second portion of the grip 110 in the recess 42a, the wall surface of the recess 42a can be made to adhere to the surface of the second portion with substantially no gaps.

[0071] In this way, the grip 110 is held by the recess 41a of the first member 41 and the recess 42a of the second member 42, so as to wrap around it in the circumferential direction.

[0072] Each of the first member 41 and the second member 42 described above is made of resin material and manufactured using a 3D printer. Here, the 3D shape data for each of the first member 41 and the second member 42 is created using the 3D shape data of the grip 110 of the welding torch 100. The 3D shape data of the grip 110 of the welding torch 100 may be data obtained by 3D shape measurement of the grip 110, or data used in the manufacture of the grip 110.

[0073] The resin material constituting the first member 41 and the second member 42 can be any material that can withstand the heat during welding and stably hold the grip 110 of the welding torch 100, and is not particularly limited, but from the viewpoint of improving the heat resistance of the holder 40, it is preferable to use a thermosetting resin. Furthermore, from the viewpoint of improving the mechanical strength of the holder 40, inorganic fillers such as silica or alumina may be added to the resin.

[0074] As shown in Figure 9, the fastener 43 has a locking member 43a and a fixing screw 43b.

[0075] The locking member 43a is attached to the first member 41 at a position in the Z2 direction relative to the recess 41a, so as to be rotatable about an axis parallel to the Y axis. By rotating the locking member 43a about this axis, it is possible to switch between a locked state in which the second member 42 is sandwiched between the first member 41 and the locking member 43a, and an unlocked state in which the second member 42 is not sandwiched. In the locked state, the end of the second member 42 in the Z2 direction is pressed toward the first member 41. In Figure 9, the locking member 43a in the unlocked state is shown by a dashed line.

[0076] The fixing screw 43b penetrates the second member 42 at a position in the Z1 direction relative to the recesses 41a and 42a, and engages with a female thread (not shown) of the first member 41. When the fixing screw 43b is rotated in the tightening direction, it presses the end of the second member 42 in the Z1 direction toward the first member 41. The fixing screw 43b can also be removed from the first member 41 by rotating it in the opposite direction to the tightening direction. This allows for the formation of the space necessary for attaching and detaching the grip 110 to the holder 40 between the first member 41 and the second member 42. Furthermore, from the viewpoint of improving workability, it is preferable that the fixing screw 43b is a screw that can be tightened without tools.

[0077] The grip 110 is held by the holder 40 by being sandwiched between the first member 41 and the second member 42. The shapes of the first member 41 and the second member 42 are determined according to the shape of the grip 110 or the configuration of the third linear motion mechanism 30, and are not limited to the example shown in Figure 9, but are arbitrary. The configuration of the fixing device 43 is arbitrary, not limited to the example shown in Figure 9, as long as it is possible to press the second member 42 toward the first member 41.

[0078] Figure 11 is a diagram illustrating the mounting state of the welding torch 100 to the holder 40. As shown in Figure 11, from the viewpoint of obtaining a good penetration depth, it is preferable that the welding torch 100 is held in the holder 40 in a direction in which the welding wire 120 extends perpendicular to the welding surface FW. The welding surface FW is a hypothetical surface that coincides with the surface of the workpiece W facing in the Z1 direction. Here, "perpendicular" includes not only cases where it is strictly perpendicular, but also cases where it is inclined within a range of ±2°. That is, it is preferable that the angle θ2 between the welding surface FW and the direction in which the welding wire 120 extends is within the range of 88° to 92°.

[0079] In the example shown in Figure 11, a groove is provided at the welding position GR between the base metal Wa and base metal Wb. From the viewpoint of obtaining a good penetration depth, the groove angle θ3 is preferably 60° to 90°, and more preferably 80° to 90°. This point will be explained later with reference to Figure 15.

[0080] 1-7. Sensor Unit Figure 12 is a front view of the sensor unit 50. Figure 13 is a diagram illustrating the space inside the sensor unit 50. As shown in Figure 12, the sensor unit 50 includes a support member 51, a sensor 52, a sensor cover 53, and an opening / closing mechanism 54.

[0081] The support member 51 is a member that is fixed to the third movable body 32 of the third linear motion mechanism 30 by screw fastening or the like. The support member 51 is made of a metal such as iron, stainless steel, or aluminum alloy. In the example shown in Figure 12, the support member 51 has a plate-shaped portion whose thickness direction is along the Y axis, and a plate-shaped portion that extends from the end of the said portion in the Z1 direction in the Y2 direction and whose thickness direction is along the Z axis.

[0082] Sensor 52 is a sensor that detects the welding position GR and is fixed to the support member 51 by screws or the like. In the example shown in Figure 12, sensor 52 is an optical sensor such as a laser sensor, also called a laser displacement meter. Although not shown, sensor 52 has a light-emitting element such as a laser diode that emits laser light and a light-receiving element such as a CMOS (Complementary Metal Oxide Semiconductor) sensor that receives the laser light reflected from the object. The light-emitting element and the light-receiving element are each housed in the case of sensor 52, and the laser light is emitted from inside the case toward the workpiece W through a window provided in the case, or the laser light reflected from the workpiece W enters the case.

[0083] For example, when measuring the groove shape, the robot 2 scans the sensor 52 in a direction intersecting the direction in which the groove extends. Based on the distance traveled by the robot 2 and the distance measured by the sensor 52, the cross-sectional shape and position of the groove can be determined. This allows the welding position GR to be detected. Then, when welding using the welding torch 100, the robot 2's operation is controlled based on the detected welding position GR, allowing the robot 2 to automatically weld the workpiece W.

[0084] The sensor cover 53 is a component that protects the sensor 52 from welding spatter. The sensor cover 53 is fixed to the opening / closing mechanism 54 by screws or the like, and is supported by the support member 51 via the opening / closing mechanism 54. In the example shown in Figure 12, the sensor cover 53 has a portion positioned in the Z2 direction relative to the sensor 52 and a portion positioned in the Y2 direction. A space S is formed between the sensor cover 53 and the sensor 52. The space S is open in the X1 and X2 directions, respectively, regardless of the state of the opening 54a.

[0085] The material used for the sensor cover 53 is not particularly limited, but from the viewpoint of preventing welding spatter from adhering, for example, aluminum or an aluminum alloy is preferably used. The sensor cover 53 may be provided as needed or omitted.

[0086] Here, the sensor cover 53 can be switched between an open state, which forms an opening 54a that exposes the window portion of the sensor 52, and a closed state, which closes the opening 54a, by the operation of the opening / closing mechanism 54. An edge E facing the Y1 direction is provided at the Z2 end of the sensor cover 53. The opening 54a is opened and closed as the edge E moves in a direction along the Y axis by the operation of the opening / closing mechanism 54. In Figure 12, the closed state of the opening 54a is shown by a solid line, and the open state of the opening 54a is shown by a dashed line.

[0087] The opening / closing mechanism 54 is an electric motor such as a servo motor or pulse motor that opens and closes the opening 54a. In the example shown in Figure 12, the opening / closing mechanism 54 opens the opening 54a by moving the sensor cover 53 in the Y2 direction, and closes the opening 54a by moving the sensor cover 53 in the Y1 direction.

[0088] Prior to welding the workpiece W, the sensor unit 50 opens its opening 54a to detect the welding position GR. On the other hand, when welding the workpiece W using the welding torch 100, the sensor unit 50 closes its opening 54a. Here, the workpiece W is positioned such that the welding position GR extends along the Z-axis. Therefore, when welding the workpiece W, the sensor unit 50 moves along the X-axis. As a result, as shown in Figure 13, an airflow is generated in the space S due to this movement. This prevents the sensor 52 from overheating during welding. In addition, the adhesion of welding spatter to the sensor 52 is effectively prevented.

[0089] 1-8. Welding Conditions Figure 14 shows the relationship between welding voltage, contact resistance, and bead shape. In Figure 14, the horizontal axis represents welding voltage [V], and the vertical axis represents the contact resistance between the workpiece and the ground cable [mΩ]. Figure 14 shows that for combinations of welding voltage higher than line A and contact resistance lower than line A, the wetting angle of the bead is less than 80°, indicating a good bead shape. Also, Figure 14 shows that for combinations of welding voltage lower than line A and contact resistance lower than line A, the wetting angle of the bead is 80° or more, indicating a poor bead shape.

[0090] The experimental conditions for the results shown in Figure 14 are as follows: Welding power supply: D-Arc welding power supply manufactured by Daihen Corporation (WB-DPS(S-2)) Welding torch: Daihen BTW500 (for semi-automatic welding) Current settings: 450A, 470A, 490A Bevel angle: 70° Welding wire protrusion length: 28mm Welding test specimen (workpiece): General structural rolled steel plate (SS400), X-groove (thickness 50 mm)

[0091] The circular dots in Figure 14 indicate the case where a tab plate welded to the workpiece W is used to connect the ground cable for applying the welding voltage to the workpiece W. The square dots in Figure 14 indicate the case where the ground cable for applying the welding voltage is connected to the workpiece W by screw fastening. The triangular dots in Figure 14 indicate the case where a wedge 230 is used to connect the ground cable for applying the welding voltage to the workpiece W.

[0092] As shown in Figure 14, the contact resistance is in the following order from lowest to highest: when the ground cable and workpiece W are connected using a tab plate, when the ground cable and workpiece W are connected by screw fastening, and when the ground cable and workpiece W are connected via a wedge 230. Therefore, a good bead is more likely to be obtained by connecting the ground cable and workpiece W using a tab plate. Also, a better bead shape is more likely to be obtained as the welding voltage is higher. In the results shown in Figure 14, a good bead shape is obtained by setting the welding voltage to 43V or higher.

[0093] Figure 15 shows the relationship between conductance and penetration depth. In Figure 15, the horizontal axis represents conductance, and the vertical axis represents penetration depth. The experimental conditions for the results shown in Figure 15 are the same as those for the results shown in Figure 14, except that the groove angle was set to 80°.

[0094] As shown in Figure 15, when the conductance is 10.5 or higher, the penetration depth becomes 6 mm or higher, resulting in a good penetration depth.

[0095] 1-9. Summary As described above, the welding apparatus 1 comprises a first linear motion mechanism 10, a second linear motion mechanism 20, a third linear motion mechanism 30, a holder 40, and a sensor unit 50.

[0096] As described above, the first linear motion mechanism 10 has a first base 11 and a first movable body 12. The first movable body 12 moves relative to the first base 11 in a direction along the X-axis, which is an example of a "first axis". The second linear motion mechanism 20 has a second base 21 and a second movable body 22. The second base 21 is detachably fixed to the first movable body 12. The second movable body 22 moves relative to the second base 21 in a direction along the Z-axis, which is an example of a "second axis" that intersects the "first axis". The third linear motion mechanism 30 has a third base 31 and a third movable body 32. The third base 31 is detachably fixed to the second movable body 22. The third movable body 32 moves relative to the third base 31 in a direction along the Y-axis, which is an example of a "third axis" that intersects the "first axis" and the "second axis". The holder 40 is attached to the third movable body 32 and detachably holds the welding torch 100 for arc welding. The sensor unit 50 is attached to the third movable body 32 and has a sensor 52 that detects the welding position GR.

[0097] As described above, the first movable body 12 and the second base 21 are shaped to be positioned relative to each other, and the second movable body 22 and the third base 31 are shaped to be positioned relative to each other. In addition, the holder 40 and the welding torch 100 are shaped to be positioned relative to each other.

[0098] In the welding apparatus 1 described above, the second base 21 is detachable from the first movable body 12, allowing for the disassembly and assembly of the first linear motion mechanism 10 and the second linear motion mechanism 20. Similarly, the third base 31 is detachable from the second movable body 22, allowing for the disassembly and assembly of the second linear motion mechanism 20 and the third linear motion mechanism 30. Thus, because the first linear motion mechanism 10, the second linear motion mechanism 20, and the third linear motion mechanism 30 can be disassembled, these linear motion mechanisms can be transported individually. Therefore, even a single operator can easily transport the welding apparatus 1, achieving excellent portability.

[0099] Furthermore, since the first movable body 12 and the second base 21 are shaped to be positioned relative to each other, the alignment of the first linear motion mechanism 10 and the second linear motion mechanism 20 during assembly can be performed in a short time. Similarly, since the second movable body 22 and the third base 31 are shaped to be positioned relative to each other, the alignment of the second linear motion mechanism 20 and the third linear motion mechanism 30 during assembly can be performed in a short time. This positioning between the linear motion mechanisms reduces the decrease in workability due to assembly after disassembly.

[0100] Furthermore, since the holder 40 detachably holds the welding torch 100, not only can automatic welding be performed by a robot using the welding device 1, but semi-automatic welding can also be performed manually using the welding torch 100 removed from the holder 40. This improves convenience for the operator. In addition, by using a commercially available welding torch, the cost of the welding device 1 can be reduced.

[0101] Furthermore, since the holder 40 and the welding torch 100 are shaped to be positioned relative to each other, the positioning of the welding torch 100 when attaching it to the holder 40 can be done in a short time. This significantly enhances the convenience for the operator.

[0102] In this embodiment, as described above, the first linear motion mechanism 10 further comprises a first rail 13, a first actuator 14, and a first cover 15. The first rail 13 guides one of the first base 11 and the first movable body 12 to move relative to the other in a direction along the X axis. The first actuator 14 generates a driving force to move one of the first base 11 and the first movable body 12 relative to the other in a direction along the X axis. The first cover 15 protects one or both of the first rail 13 and the first actuator 14 from welding spatter. This prevents welding spatter from adhering to one or both of the first rail 13 and the first actuator 14. As a result, the frequency of maintenance of the first linear motion mechanism 10 can be significantly reduced. Therefore, work interruptions due to maintenance of the first linear motion mechanism 10 are reduced, and work efficiency can be improved.

[0103] Similarly, as described above, the second linear motion mechanism 20 further comprises a second rail 23, a second actuator 24, and a second cover 25. The second rail 23 guides one of the second base 21 and the second movable body 22 to move relative to the other in a direction along the Z-axis. The second actuator 24 generates a driving force to move one of the second base 21 and the second movable body 22 relative to the other in a direction along the Z-axis. The second cover 25 protects one or both of the second rail 23 and the second actuator 24 from welding spatter. This prevents welding spatter from adhering to one or both of the second rail 23 and the second actuator 24. As a result, the maintenance frequency of the second linear motion mechanism 20 can be significantly reduced. Therefore, work interruptions due to maintenance of the second linear motion mechanism 20 are reduced, improving work efficiency.

[0104] Furthermore, as mentioned above, the third linear motion mechanism 30 further comprises a third rail 33, a third actuator 34, and a third cover 35. The third rail 33 guides one of the third base 31 and the third movable body 32 to move relative to the other in a direction along the Y-axis. The third actuator 34 generates a driving force to move one of the third base 31 and the third movable body 32 relative to the other in a direction along the Y-axis. The third cover 35 protects one or both of the third rail 33 and the third actuator 34 from welding spatter. This prevents welding spatter from adhering to one or both of the third rail 33 and the third actuator 34. As a result, the maintenance frequency of the third linear motion mechanism 30 can be significantly reduced. Therefore, work interruptions due to maintenance of the third linear motion mechanism 30 are reduced, improving work efficiency.

[0105] Furthermore, as described above, the first movable body 12 has a first positioning pin 12a, and the second base 21 has a first positioning hole 21a that fits into the first positioning pin 12a. Similarly, the second movable body 22 has a second positioning pin 22a, and the third base 31 has a second positioning hole 31a that fits into the second positioning pin 22a. By using such positioning pins and positioning holes, the relative positioning of the first linear motion mechanism 10, the second linear motion mechanism 20, and the third linear motion mechanism 30 can be performed with a relatively simple configuration.

[0106] The second base 21 may have a first positioning pin. In this case, the first movable body 12 has a first positioning hole that fits onto the first positioning pin. Similarly, the third base 31 may have a second positioning pin. In this case, the second movable body 22 has a second positioning hole that fits onto the second positioning pin.

[0107] As mentioned above, the first positioning pin 12a has a cylindrical portion 12a1 and a tapered portion 12a2 that protrudes from the tip of the cylindrical portion 12a1. When the total length of the first positioning pin 12a is L, the length of the cylindrical portion 12a1 is La, and the length of the tapered portion 12a2 is Lb, it is preferable that the relationship L ≤ 10 mm, La ≤ 3 mm, and 3 mm ≤ Lb ≤ (L - La) are satisfied. The second positioning pin 22a has the same shape as the first positioning pin 12a. By using the first positioning pin 12a and the second positioning pin 22a with such tapered shapes, the workability of disassembling and assembling the first linear motion mechanism 10, the second linear motion mechanism 20, and the third linear motion mechanism 30 can be improved.

[0108] Furthermore, as mentioned above, the welding torch 100 performs arc welding using an embedded arc. To perform arc welding using an embedded arc, it is necessary to control the positional relationship between the welding position GR and the welding torch 100 with high precision. Since the welding apparatus 1 uses three linear motion mechanisms, it has the advantage of being able to easily improve the positional accuracy of the welding torch 100 relative to the linear welding position GR compared to a configuration using a multi-joint robot with multiple joints due to a rotation mechanism. For this reason, an embedded arc can be generated stably.

[0109] Furthermore, as mentioned above, the welding torch 100 has a grip 110 for a person to hold. The holder 40 has a plate-shaped first member 41 fixed to the third movable body 32, a second member 42 positioned on top of the first member 41, and a fixing device 43 that presses the second member 42 toward the first member 41. The first member 41 has a recess 41a for holding the grip 110. The second member 42 has a recess 42a for holding the grip 110. The grip 110 is fixed by being sandwiched between the first member 41 and the second member 42. With such a holder 40, the grip 110 can be held stably. Moreover, a holder 40 that can be attached to and detached from the welding torch 100 can be realized with a relatively simple configuration.

[0110] As mentioned above, the recesses 41a and 42a have shapes complementary to the grip 110. Therefore, even if the grip 110 has a complex shape, the welding torch 100 can be stably attached to the holder 40 in a desired position and orientation.

[0111] Furthermore, as mentioned above, the holder 40 holds the welding torch 100 in a orientation such that the welding wire 120 extends perpendicular to the welding surface FW. This allows for arc welding in a stable buried arc state.

[0112] Furthermore, as mentioned above, the sensor unit 50 further includes a sensor cover 53. The sensor cover 53 is attached to the third movable body 32 and protects the sensor 52 from welding spatter. This prevents welding spatter from adhering to the sensor 52. As a result, the welding position GR can be detected with high accuracy using the sensor 52 in a stable manner over a long period of time. In addition, the maintenance frequency of the sensor unit 50 can be significantly reduced. Therefore, work interruptions due to maintenance of the sensor unit 50 are reduced, thereby improving work efficiency.

[0113] Furthermore, as mentioned above, it is preferable that the sensor 52 is a laser sensor. In this case, the welding position GR can be detected with high precision. As a result, high-precision welding can be achieved.

[0114] Furthermore, as mentioned above, the sensor cover 53 has an opening 53a that exposes the sensor 52. The sensor unit 50 further has an opening / closing mechanism 54 that opens and closes the opening 53a. Therefore, the opening 53a can be closed when welding is not in use. As a result, the sensor 52 can be more reliably protected from welding spatter.

[0115] 2. Variations This disclosure is not limited to the embodiments described above, and various modifications described below are possible. Furthermore, each embodiment and each modification may be combined as appropriate.

[0116] 2-1. Modification Example 1 In the above-described embodiment, a configuration using a positioning pin and a positioning hole for positioning between the linear motion mechanisms is exemplified, but the present invention is not limited to this configuration. That is, it is only necessary that the first movable body and the second base have a shape that positions each other, and the second movable body and the third base have a shape that positions each other.

Explanation of Reference Numerals

[0117] 1... Welding device, 2... Robot, 10... First linear motion mechanism, 11... First base, 12... First movable body, 12a... First positioning pin, 12a1... Cylindrical portion, 12a2... Tapered portion, 12b... Threaded hole 13... First rail, 14... First actuator, 15... First cover, 15a... Through hole, 16... Handle, 17... Leg, 17a... Height adjustment mechanism, 20... Second linear motion mechanism, 21... Second base, 21a... First positioning hole, 22... Second movable body, 22a... Second positioning pin, 22b... Threaded hole, 23... Second rail, 24... Second actuator, 25... Second cover, 25a... Through hole, 26... Handle, 27... Side cover, 28... Top plate, 30... Third linear motion mechanism, 31... Third base, 31a... Second positioning hole, 31b... Screw, 32... Third movable body, 33... Third rail, 34... Third actuator, 35... Third cover, 36... Handle, 37... Support member, 40... Holder, 41... First member, 41a... Recess, 42... Second member, 42a... Recess, 43... Fixture, 43a... Locking member, 43b... Fixing screw, 50... Sensor unit, 50 mm... Thickness, 51... Support member, 52... Sensor, 53... Sensor cover, 54... Opening / closing mechanism, 54a... Opening, 100... Welding torch, 110... Grip, 120... Welding wire, 200... Restraint jig, 210... Base, 211... Groove, 220... Restraint portion, 230... Wedge, 490... Holder, A... Straight line, B... Straight line, E... Edge, FW... Welding surface, GR... Welding position, S... Space, W... Workpiece, W1... Width, W2... Width, Wa... Base material, Wb... Base material, θ1... Tilt angle, θ2... Angle, θ3... Groove angle.

Claims

1. A first linear motion mechanism having a first base and a first movable body that moves in a direction along a first axis relative to the first base, A second linear motion mechanism comprising: a second base detachably fixed to the first movable body; and a second movable body that moves relative to the second base in a direction along a second axis intersecting the first axis; A third linear motion mechanism comprising: a third base detachably fixed to the second movable body; and a third movable body that moves relative to the third base in a direction along a third axis intersecting the first and second axes; A holder attached to the third movable body, which detachably holds a welding torch for arc welding, The sensor unit, which is attached to the third movable body and has a sensor for detecting the welding position, The first movable body and the second base are shaped to be positioned relative to each other. The second movable body and the third base are shaped to be positioned relative to each other. The holder and the welding torch are shaped to be positioned relative to each other. The welding torch has a grip for a person to hold, The retainer is A plate-shaped first member fixed to the third movable body, A plate-shaped second member is placed on top of the first member, It includes a fixing device that presses the second member toward the first member, Each of the first member and the second member has a recess for holding the grip, The grip is fixed by being sandwiched between the first member and the second member. The recess has a shape complementary to the grip. Welding equipment.

2. The first linear motion mechanism is, A first rail that guides one of the first base and the first movable body to move relative to the other in a direction along the first axis, A first actuator that generates a driving force to move one of the first base and the first movable body relative to the other in a direction along the first axis, The present invention further comprises a first cover that protects one or both of the first rail and the first actuator from welding spatter, The welding apparatus according to claim 1.

3. The second linear motion mechanism is, A second rail that guides one of the second base and the second movable body to move relative to the other in a direction along the second axis, A second actuator that generates a driving force to move one of the second base and the second movable body relative to the other in a direction along the second axis, The present invention further comprises a second cover that protects one or both of the second rail and the second actuator from welding spatter, The welding apparatus according to claim 1.

4. The third linear motion mechanism is, A third rail that guides one of the third base and the third movable body to move relative to the other in a direction along the third axis, A third actuator that generates a driving force to move one of the third base and the third movable body relative to the other in a direction along the third axis, The present invention further comprises a third cover that protects one or both of the third rail and the third actuator from welding spatter, The welding apparatus according to claim 1.

5. Of the first movable body and the second base, one has a first positioning pin, and the other has a first positioning hole that fits into the first positioning pin. Of the second movable body and the third base, one has a second positioning pin, and the other has a second positioning hole that fits into the second positioning pin. The welding apparatus according to claim 1.

6. Each of the first positioning pin and the second positioning pin is, The cylindrical part, It has a tapered portion that protrudes from the tip of the cylindrical portion, When the total length of the first positioning pin and the second positioning pin is L, the length of the cylindrical portion is La, and the length of the tapered portion is Lb, then L ≤ 10 mm. The following conditions are met: La ≤ 3 mm and 3 mm ≤ Lb ≤ (L - La). The welding apparatus according to claim 5.

7. The welding torch performs arc welding using an embedded arc. The welding apparatus according to claim 1.

8. The holder holds the welding torch in a orientation such that the welding wire extends perpendicular to the welding surface. The welding apparatus according to claim 1.

9. The aforementioned sensor unit is The third movable body is further equipped with a sensor cover that protects the sensor from welding spatter, The welding apparatus according to claim 1.

10. The aforementioned sensor is a laser sensor. The welding apparatus according to claim 9.

11. The sensor cover has an opening that exposes the sensor, The sensor unit further includes an opening and closing mechanism for opening and closing the opening. The welding apparatus according to claim 9.

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