Rotary torch

Abstract

To provide a rotary torch with a simple structure and easy maintenance. [Solution] The rotary torch 10 comprises a hollow columnar housing 25 having a side surface 25a, a power supply hole 25b extending perpendicularly to the central axis 1 and penetrating the side surface 25a; a hollow body 29 rotatably disposed within the housing 25 about the central axis 1, the body 29 having an electrode 33 at its tip; a wire holder 19 disposed inside the body 29 for supplying the welding wire 3; a brush 41 disposed in the power supply hole 25b, in contact with the outer surface of the body 29, and supplying power to the electrode 33 via the body 29; and a cooler 43 disposed in contact with the brush 41 and dissipating heat from the electrode 33 via the brush 41.

Description

Technical Field

[0001] The present invention relates to a rotary torch.

Background Art

[0002] Conventionally, a rotary torch having a torch body, a wire guide, a rotating cylinder, and a non-consumable electrode has been known (Patent No. 6963699; hereinafter, Patent Document 1). The wire guide feeds a filler wire. The rotating cylinder surrounds the wire guide and is rotatably supported by the torch body. The non-consumable electrode is disposed at the tip of the rotating cylinder.

Summary of the Invention

Problems to be Solved by the Invention

[0003] The rotary torch of Patent Document 1 has a complicated mechanical structure and is difficult to maintain the power supply part. An object of the present invention is to provide a rotary torch having a simple structure and being easy to maintain.

Means for Solving the Problems

[0004] A first aspect of the present invention is <00000​​​​​​​​​​​​​​The housing may have multiple power supply holes. The multiple power supply holes may be arranged, for example, in a rotationally symmetrical manner with respect to the central axis. The brush is made of a material with high electrical and thermal conductivity. For example, the brush is a carbon brush. The brush may also be guided through the power supply hole.

[0006] The cooling passage meanders inside the cooling body. The cooling body may be flat. Preferably, when viewed from the central axis, the surface of the cooling body is in close contact with the back of the brush. The coolant is, for example, water. The coolant removes heat from the cooling body.

[0007] The housing may support a motor and a transmission. The transmission is, for example, a toothed pulley and a toothed belt. The motor rotates the body via the transmission.

[0008] The body may have a power supply section. The power supply section is cylindrical and in contact with the brush. The body is supported by the housing via a first bearing at the base end of the power supply hole. The body is also supported by the housing via a second bearing at the tip end of the power supply hole and power supply section. A first seal may be positioned between the power supply hole and power supply section and the first bearing. The first seal seals the space between the body and the housing. A second seal may be positioned between the power supply hole and power supply section and the second bearing. The second seal seals the space between the body and the housing. The body may have a sealing portion. The sealing portion is in contact with the second seal. The sealing portion is positioned between the brush and the second bearing.

[0009] An insulating section may be placed between the body and the transmission device. The insulating section electrically insulates the body from the transmission device. The insulating section may be placed between the first seal and the body. The insulating section is located on the base end side of the brushes and power supply section. A support shaft may be positioned between the insulating part and the transmission device. The support shaft may have a seal flange. The seal flange is in contact with the first seal.

[0010] A rotary torch may have an inner nozzle. The inner nozzle may be made of an electrically insulating material. The inner nozzle surrounds the tip of the wire holder. The inner nozzle sprays shielding gas around the wire holder and welding wire. The inner nozzle may insulate the wire holder from the body. A rotary torch may have an insulating cover. The insulating cover insulates the outer circumference of the wire holder from the body. [Effects of the Invention]

[0011] According to the present invention, a rotary torch with a simple structure and easy maintenance can be provided. [Brief explanation of the drawing]

[0012] [Figure 1] Longitudinal section of the rotary torch of the embodiment [Figure 2] Sectional view along line II-II in Figure 1 [Figure 3] Sectional view along line III-III in Figure 2 [Modes for carrying out the invention]

[0013] As shown in Figure 1, the welding machine 9 of this embodiment includes a rotary torch 10, a welding power source 55, a chiller 57, a gas source 61, a wire supply device 63, and a moving device 65. The welding machine 9 welds to the workpiece 2. Hereinafter, the lower part of Figure 1 will be referred to as the tip, and the upper part of Figure 1 will be referred to as the base.

[0014] As shown in Figures 1 and 2, the rotary torch 10 includes a pulley case 11, a motor 16, a bearing 12, a support shaft 13, a seal 14, a driven pulley 15, a driving pulley 17, an endless belt 18, a wire holder 19, an insulating cover 20, a roller bracket 21, a roller 22, an inner nozzle 23, a housing 25, a bearing 26, an insulating part 27, a body 29, a seal 30, an electrode holder 31, an outer nozzle 35, an electrode 33, a plurality (six in this embodiment) of brushes 41, a plurality (three in this embodiment) of coolers 43, a spring (elastic body) 49, a connector 46, and a plurality (three in this embodiment) of covers 51. Figure 1 is a cross-sectional view taken along line II of Figure 2.

[0015] The support shaft 13, driven pulley 15, insulating part 27, body 29, electrode holder 31, and electrode 33 rotate around the central axis 1. The pulley case 11, seal 14, wire holder 19, inner nozzle 23, housing 25, seal 30, outer nozzle 35, brush 41, cooler 43, spring (elastic body) 49, coupling 46, and cover 51 do not rotate.

[0016] The pulley case 11 is a hollow box shape. The pulley case 11 has a circular opening 11a at its tip. The motor 16 is positioned inside the pulley case 11.

[0017] The support shaft 13 extends around the central axis 1. The support shaft 13 is supported by the pulley case 11 via a bearing 12. The support shaft 13 is hollow. The support shaft 13 has a seal flange 13a. The seal flange 13a is located at the tip of the support shaft 13. The seal flange 13a has a larger diameter than the central part of the support shaft 13.

[0018] The driven pulley 15 is fastened to the base end of the support shaft 13. The driven pulley 15 may be integrated with the support shaft 13. The driving pulley 17 is located inside the pulley case 11 and connected to the motor 16. Both the driven pulley 15 and the driving pulley 17 are toothed pulleys. The endless belt 18 is mounted between the driven pulley 15 and the driving pulley 17.

[0019] The seal 14 is disposed in the opening 11a. The seal 14 liquid-tightly seals between the opening 11a and the seal flange 13a.

[0020] The housing 25 is a hollow hexagonal columnar shape. The housing 25 extends along the central axis 1. The housing 25 is connected to the tip of the pulley case 11. The housing 25 has a side surface 25a, a power supply hole 25b, and a nozzle bracket 25c. The side surface 25a is the outer peripheral surface of the pulley case 11. The power supply hole 25b is disposed on the side surface 25a and extends in the radial direction. As shown in FIG. 3, the power supply hole 25b has a rectangular cross section. The central axis of the power supply hole 25b is referred to as the power supply axis 5. The housing 25 has a plurality (in this embodiment, three) of power supply holes 25b. The plurality of power supply holes 25b are arranged rotationally symmetric (in this embodiment, three-fold symmetry) about the central axis 1. The power supply hole 25b guides the cooler 43 in the radial direction.

[0021] As shown in FIG. 1, the nozzle bracket 25c extends along the central axis 1 and is disposed at the tip of the housing 25. The nozzle bracket 25c is a thin-walled cylindrical shape. The housing 25 is made of an insulator. Desirably, the housing 25 has higher heat insulation than metal. The housing 25 is, for example, made of plastic. The bearing 26 is disposed on the inner surface of the tip portion of the housing 25.

[0022] The insulating portion 27 has a flange portion 27a and a body portion 27b. The insulating portion 27 is hollow. The flange portion 27a is connected to the support shaft 13. The flange portion 27a has substantially the same outer diameter as the seal flange 13a. The body portion 27b is disposed at the tip of the flange portion 27a. The body portion 27b has substantially the same inner diameter and outer diameter as the body 29. The insulating portion 27 is made of an insulator. Desirably, the insulating portion 27 has higher heat insulation than metal. The insulating portion 27 is, for example, made of plastic.

[0023] The body 29 is hollow and cylindrical, extending along the central axis 1. The body 29 is made of a metal with high electrical conductivity. The body 29 has high thermal conductivity. For example, the body 29 is made of pure copper or a copper alloy. The body 29 has a power supply section 29a, a sealing section 29b, a vibration damping section 29c, and an electrode mounting section 29d.

[0024] The power supply unit 29a is positioned from the center to the base end of the body 29. The power supply unit 29a is a straight cylinder centered on the central axis 1. The power supply unit 29a is connected to the body portion 27b. The seal portion 29b is positioned between the power supply portion 29a and the bearing 26. The seal portion 29b is a straight cylinder with an outer diameter slightly larger than that of the power supply portion 29a. The vibration damping portion 29c is positioned on the inner surface of the body 29. The vibration damping portion 29c is positioned at the base end or the center of the body 29. The electrode mounting portion 29d is located at the tip of the body 29. The electrode mounting portion 29d is a groove that extends in the radial direction.

[0025] The body 29 is made of a highly conductive metal. For example, the body 29 may be made of an aluminum alloy, aluminum, a copper alloy, or copper. The body 29 is supported by the housing 25 via a bearing 26. Preferably, the body 29 is supported at the tip. The seal portion 29b is positioned more towards the base end than the bearing 26. The support shaft 13, the insulating part 27, and the body 29 are integrally supported at their base end by bearing 12 and at their tip by bearing 26.

[0026] The seal 30 seals the gap between the housing 25 and the sealing portion 29b with liquid. The electrode holder 31 is plate-shaped. The electrode holder 31 is made of a metal with high conductivity. The electrode holder 31 has high thermal conductivity. For example, the electrode holder 31 is made of pure copper or a copper alloy. The electrode holder 31 is bolted to the electrode mounting portion 29d. The electrode holder 31 is removable from the body 29. The electrode holder 31 has an electrode mounting hole 31a. The electrode mounting hole 31a is a round hole into which the electrode 33 is mounted. The electrode 33 is, for example, a tungsten electrode. The electrode 33 is inclined so that its tip is radially inward.

[0027] The insulating cover 20 is hollow and cylindrical, extending along the central axis 1. The insulating cover 20 is positioned radially outward of the wire holder 19. The base end of the insulating cover 20 is supported by the pulley case 11. The insulating cover 20 insulates the outer circumference of the wire holder 19 from the base end to the center. The insulating cover 20 is made of an insulating material. For example, the insulating cover 20 is made of insulating plastic.

[0028] The wire holder 19 has a wire insertion hole 19a, a tip portion 19b, and a plurality (six in this embodiment) of gas flow paths 19c. The wire holder 19 is hollow cylindrical and extends along the central axis 1. The wire holder 19 is supported by the insulating cover 20. The tip portion 19b protrudes from the insulating cover 20. The tip portion 19b becomes smaller in diameter towards the tip. The wire insertion hole 19a extends along the central axis 1 and penetrates the wire holder 19. The gas passage 19c is located radially outward from the wire insertion hole 19a. The gas passage 19c extends parallel to the central axis 1. The gas passage 19c is connected to the gas source 61 at the base end of the wire holder 19. The gas passage 19c is connected to the inner nozzle 23. The multiple gas passages 19c are arranged rotationally symmetrically with respect to the central axis 1.

[0029] The roller bracket 21 is positioned at the base end of the insulating cover 20. The roller 22 is rotatably mounted on the roller bracket 21. The rollers 22 are alternately positioned on both sides of the welding wire 3. The rollers 22 stretch the welding wire 3 and smoothly supply it to the wire insertion hole 19a.

[0030] The inner nozzle 23 has a bulge 23b. The inner nozzle 23 is a thin-walled cylindrical shape. The inner nozzle 23 is supported from the center to the tip of the insulating cover 20, with the central axis 1 as the center axis. The inner nozzle 23 surrounds the tip 19b. The inner nozzle 23 is made of an insulator. For example, the inner nozzle 23 is made of insulating plastic. The inner nozzle 23 insulates the outer circumference of the wire holder 19 from the center to the tip. The bulge 23b is positioned with a small gap between it and the vibration-preventing portion 29c.

[0031] The outer nozzle 35 is thin-walled and cylindrical, with a smaller diameter at the tip. The outer nozzle 35 is mounted on the nozzle bracket 25c around the central axis 1. The outer nozzle 35 surrounds the inner nozzle 23, the welding wire 3, the wire holder 19, and the electrode 33. The outer nozzle 35 is connected to the gas source 61.

[0032] A pair of brushes 41 are arranged along the central axis. A pair of brushes 41 is placed in each of the three power supply holes 25b. The brushes 41 are carbon brushes. As shown in Figure 2, the brush 41 has a cylindrical surface 41a, a back surface 41b, and a connecting portion 41c. As shown by the dashed line in Figure 3, when viewed from the side (right side in Figure 1), the brush 41 is rectangular prism-shaped. The cylindrical surface 41a is centered on the central axis 1. The cylindrical surface 41a has the same diameter as the power supply section 29a. The cylindrical surface 41a slides against the power supply section 29a. The back surface 41b is located on the back of the brush 41 when viewed from the central axis 1. The back surface 41b is perpendicular to the power supply axis 5. The connecting section 41c is a right circular column extending parallel to the power supply axis 5. The connecting section 41c is located at the center of the back surface 41b. The connecting section 41c is connected to the power supply cable 56.

[0033] Coolers 43 are positioned in each power supply hole 25b. One cooler 43 is fastened to a set of brushes 41. As shown in Figures 2 and 3, the coolers 43 are rectangular plate-shaped. The coolers 43 are made of a highly conductive metal. For example, the coolers 43 are made of aluminum or copper. The cooler 43 has a cooling plate (cooling body) 43a, a cooling passage 43b, a side surface 43c, a spring guide hole 43d, and a through hole 43e.

[0034] The cooling plate 43a has a first plate 43a1 and a second plate 43a2. The first plate 43a1 and the second plate 43a2 are perpendicular to the power supply axis 5. The first plate 43a1 and the second plate 43a2 are joined together in close contact. The first plate 43a1 is in close contact with the back surface 41b. The cooling passage 43b is located between the first plate 43a1 and the second plate 43a2. For example, the cooling passage 43b is located on the first plate 43a1. The cooling passage 43b has a rectangular cross-section and is S-shaped. The side surface 43c is the side surface of the cooler 43. The side surface 43c is guided to the power supply hole 25b. The side surface 43c may slide against the power supply hole 25b. The through hole 43e extends parallel to the power supply shaft 5 and passes through the cooler 43. The through hole 43e is coaxial with and has the same diameter as the connection part 41c. The connection part 41c may abut against the through hole 43e. The power supply cable 56 passes through the through hole 43e. The spring guide hole 43d is located on the back surface of the second plate 43a2 when viewed from the central axis 1. The spring guide hole 43d is coaxial with the through hole 43e.

[0035] The connectors 46 are positioned at both ends of the cooling passage 43b. The connectors 46 connect the cooling passage 43b to the chiller 57. The connectors 46 extend parallel to the power supply shaft 5.

[0036] As shown in Figure 2, the cover 51 has a spring guide hole 51a, a cable hole 51b, and a connector hole 51c. The cover 51 is a rectangular plate and covers the opening of the power supply hole 25b. The spring guide hole 51a is located radially inward of the cover 51. The cable hole 51b and the spring guide hole 51a extend coaxially with the connector 41c. The spring guide hole 51a has the same diameter as the spring guide hole 43d. The spring guide hole 51a faces the spring guide hole 43d. The cable hole 51b is a through hole. The power supply cable 56 passes through the cable hole 51b. The connector hole 51c is a through hole. The connector 46 passes through the connector hole 51c.

[0037] The spring 49 is a compression coil spring. The spring 49 is installed between the spring guide hole 51a and the spring guide hole 43d. The spring 49 biases the brush 41 to the body 29 via the cooler 43.

[0038] The welding power supply 55 supplies welding current between the rotary torch 10 and the workpiece 2. The first output terminal of the welding power supply 55 is connected to the brush 41 via the power supply cable 56. The second output terminal of the welding power supply 55 is connected to the workpiece 2. The workpiece 2 is grounded. The welding current flows to the workpiece 2 through the brush 41, the body 29, and the electrode 33. The welding power supply 55 controls the chiller 57, the gas source 61, and the wire supply device 63.

[0039] The gas source 61 includes a gas cylinder and a flow regulator. The gas source 61 supplies shielding gas 8 to the wire holder 19 and the outer nozzle 35. The shielding gas 8 is ejected from the inner nozzle 23 and the outer nozzle 35.

[0040] The chiller 57 is connected to the cooling passage 43b via a connector 46. The chiller 57 circulates and supplies the coolant 4 to the cooler 43. The chiller 57 cools the heated coolant 4 by exchanging heat in the cooler 43.

[0041] The wire supply device 63 supplies the welding wire 3 to the wire holder 19. The moving device 65 is connected to the pulley case 11. The moving device 65 is, for example, a robot. The moving device 65 is, for example, an articulated robot, a parallel link robot, or a right-axis robot. Articulated robots are, for example, vertical articulated robots or horizontal articulated robots. The moving device 65 is numerically controlled to move the rotary torch 10 freely relative to the workpiece 2.

[0042] In the rotary torch 10 of this embodiment, the cooler 43 and brush 41 can be removed and replaced simply by removing the cover 51. Furthermore, the brush 41 is biased to the body 29 by a spring 49 via the cooler 43. Therefore, a stable welding current can be supplied.

[0043] The electrode 33 becomes extremely hot due to arc discharge and radiant heat from the molten pool formed in the workpiece 2. Therefore, it is necessary to cool the electrode 33. The cooler 43 is directly connected to the brush 41, and its back surface 41b is in close contact with the cooler 43. The cylindrical surface 41a slides against the power supply section 29a while being biased. The brush 41 is biased against the body 29. The electrode holder 31, body 29, brush 41, and cooler 43 have high conductivity. The cooling passage 43b extends in a meandering manner within the cooler 43. Therefore, the surface area of ​​the cooling passage 43b is large. As a result, the heat from the electrode 33 is effectively dissipated into the coolant 4 via the body 29, brush 41, and cooler 43. In addition, the positions of the brush 41 and the electrode 33 can be brought closer together compared to the conventional technology. The cooler 43 supplies cooling heat via the brush 41. By bringing the cooler 43 and the electrode 33 closer together, the electrode 33 can be cooled effectively.

[0044] The body 29 is connected to the support shaft 13 via an insulating section 27. The body 29, brush 41, spring 49, cooler 43, and coupling 46 are supported by the housing 25. The insulating section 27 and housing 25 have high insulating properties. Therefore, they suppress the flow of welding current to the moving device 65 and motor 16 via the pulley case 11.

[0045] The outer circumference of the wire holder 19 is insulated from the body 29, support shaft 13, and pulley case 11 by the insulating cover 20 and inner nozzle 23. This prevents welding current from flowing to the pulley case 11 through the wire holder 19. Workpiece 2 and roller bracket 21 are grounded.

[0046] The support shaft 13, the insulating part 27, and the body 29 are fastened to each other and rotate as a single unit. The support shaft 13, the insulating part 27, and the body 29 are supported at both ends by bearings 12 and 26. As a result, the runout of the support shaft 13, the insulating part 27, and the body 29 is suppressed.

[0047] The inner nozzle 23 has a bulge 23b. The bulge 23b is positioned with a small gap between it and the vibration-preventing portion 29c. The inner nozzle 23 supports the tip of the wire holder 19. The base end of the wire holder 19 is supported by the pulley case 11 via the insulating cover 20. This suppresses vibration of the wire holder 19.

[0048] The body 29 is powered by the brush 41 at the power supply unit 29a. The brush 41 is connected to the cooler 43. The power supply unit 29a is supported by the bearing 12 and the bearing 26, with the seal 14 and the seal 30 in between. The seals 14 and 30 prevent wear particles from the brush 41 from falling onto the workpiece 2. Also, even if coolant 4 leaks from the cooler 43, the seals 14 and 30 prevent the coolant 4 from coming into contact with the bearings 12 and 26. The seals 14 and 30 prevent wear particles from the brush 41 and the coolant 4 from flowing onto the electrode 33, the tip of the welding wire 3, and the area around the workpiece 2.

[0049] The present invention is not limited to the embodiments described above, and various modifications are possible without departing from the spirit of the invention. All technical matters included in the technical concept described in the claims are covered by the present invention. The embodiments described above are preferred examples, but those skilled in the art can realize various alternatives, modifications, variations, or improvements from the contents disclosed herein, and these are included in the technical scope described in the appended claims. [Explanation of symbols]

[0050] 1 Center axis 3. Welding wire 10 Rotating Torch 19 Wire holder 25 Housing 25a side 25b Power supply hole 29 Body 33 electrode 41 brushes 43 Cooler

Claims

1. A hollow columnar housing having sides, the housing having a power supply hole extending perpendicular to the central axis and penetrating the sides, A hollow body rotatably disposed within the housing about the central axis, the body having an electrode at its tip, A wire holder, which is located inside the body and supplies welding wire, A brush is positioned in the power supply hole, contacts the outer surface of the body, and supplies power to the electrode via the body. A cooler is positioned in contact with the brush and dissipates heat from the electrode via the brush, A rotating torch having [a certain feature].

2. The aforementioned cooler is, A cooling body that contacts the aforementioned brush, A cooling passage is provided within the aforementioned cooling body through which the coolant passes, Having, The rotary torch according to claim 1.

3. The body further includes a spring that integrally biases the brush and the cooler. A rotary torch according to claim 1 or 2.

4. The cooler is positioned on the back of the brush when viewed from the central axis, A rotary torch according to any one of claims 1 to 3.

5. The cooling body is guided into the power supply hole, A rotary torch according to any one of claims 2 to 4.

6. The housing has electrical insulation properties. A rotary torch according to any one of claims 1 to 5.

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