Welding torch

Abstract

To improve durability of a collet body containing copper as a main component.SOLUTION: A welding torch 1 includes an electrode rod 100, and a collet 50. The collet 50 supports the outer periphery of the electrode rod 100. The collet 50 includes a body part 150, and a plated layer 160. The body part 150 is composed of a material containing copper as a main component. The plated layer 160 coats at least a part of the surface of the body part 150, and is composed of metal different from the material of the body part 150.SELECTED DRAWING: Figure 2

Description

Technical Field

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

Background Art

[0002] As a prior art document disclosing a welding torch, there is Japanese Patent Application Laid-Open No. 2010-167443 (Patent Document 1). The welding torch described in Patent Document 1 includes a collet that supports an electrode. When a material mainly composed of iron is used for the collet, a plating process is performed to prevent rust on the surface of the collet.

[0003] As a prior art document disclosing a TIG welding torch, there is Japanese Patent Application Laid-Open No. 7-32154 (Patent Document 2). The TIG welding torch described in Patent Document 2 includes a collet and a collet body. The collet holds an electrode. The collet body holds the collet. The collet body is made of copper or a copper alloy. A ceramic coating or a metal plating is applied to the surface of the collet body.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] When performing high-power welding or multiple welds, deformation or wear of the collet body mainly composed of copper is likely to occur. There is room to improve the durability of the collet body in order to suppress deformation or wear of the collet body.

[0006] The present invention has been made to solve the above problems, and an object thereof is to provide a welding torch capable of improving the durability of a collet body mainly composed of copper.

Means for Solving the Problems

[0007] The welding torch according to the present invention includes an electrode rod and a collet. The collet supports the outer periphery of the electrode rod. The collet includes a main body portion and a plating layer. The main body portion is made of a material containing copper as a main component. The plating layer covers at least a part of the surface of the main body portion and is made of a metal different from the material of the main body portion.

[0008] In this case, by covering at least a part of the surface of the main body portion of the collet mainly composed of copper with a plating layer made of a material different from that of the main body portion, the durability of the collet body can be improved.

[0009] In one embodiment of the present invention, the plating layer is made of a metal having a melting point higher than that of the material of the main body portion.

[0010] Thereby, since the main body portion can maintain its material strength even at high temperatures, the durability of the collet body can be improved.

[0011] In one embodiment of the present invention, the plating layer is made of a metal mainly composed of nickel.

[0012] In this case, compared with a plating layer mainly composed of silver or gold, nickel has a high melting point and a low cost, so that the durability of the collet body can be improved by a plating layer having high strength and high versatility.

[0013] In one embodiment of the present invention, the plating layer is made of a metal mainly composed of silver.

[0014] In this case, by forming the plating layer mainly composed of silver, which has better thermal conductivity compared to copper and lower cost compared to gold, even when the arc output increases and the collet is heated, heat can be easily dissipated from the plating layer, and a highly versatile plating layer can be formed. Therefore, the durability of the collet body can be improved.

[0015] In one embodiment of the present invention, the welding torch further includes a collet body. The collet body is configured to allow an inert gas to flow between it and the collet while supporting a part of the outer periphery of the collet, and is mainly composed of copper. On the outer periphery of the collet, a plating layer is located at least in part.

[0016] In this case, by arranging the plating layer of a dissimilar metal at the position where the collet and the collet body are in contact, it is possible to prevent a state in which the collet and the collet body are in contact with the same kind of metal mainly composed of copper and wear is likely to progress at the contact portion of the collet and the collet body. Therefore, wear of the collet and the collet body can be suppressed.

Advantages of the Invention

[0017] According to the present invention, the durability of the collet body mainly composed of copper can be improved.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

Figure 3

Modes for Carrying Out the Invention

[0019] Hereinafter, the welding torch according to each embodiment of the present invention will be described with reference to the drawings. In the following description of the embodiments, the same or corresponding parts in the drawings are denoted by the same reference numerals, and the description thereof will not be repeated.

[0020] In the drawings, the axial direction in which the electrode rod extends is defined as the DR1 direction. In the axial direction (DR1 direction), the side where the electrode rod is pointed is defined as one end side, and the opposite side is defined as the other end side.

[0021] (Embodiment 1) First, the structure of the welding torch will be described. FIG. 1 is a cross-sectional view showing the configuration of the welding torch according to Embodiment 1 of the present invention. As shown in FIG. 1, the welding torch 1 according to Embodiment 1 of the present invention is used, for example, in TIG (Tungsten Inert Gas) welding.

[0022] The welding torch 1 according to the present embodiment includes a torch body 10, a jacket 20, a collet body 30, a nozzle 40, a collet 50, and an electrode rod 100.

[0023] The torch body 10 is a part connected to a torch handle (not shown). The torch body 10 includes a cover portion 11 and a conductive portion 12.

[0024] The cover portion 11 is made of an insulating resin member. The cover portion 11 protects the conductive portion 12. The conductive portion 12 is disposed inside the cover portion 11. The conductive portion 12 is in contact with the collet body 30 on the inner peripheral surface. The conductive portion 12 is connected to a water-cooling or air-cooling mechanism (not shown). The conductive portion 12 constitutes a part of the heat transfer path for cooling the electrode rod 100.

[0025] Inside the cover portion 11, an electric cable 13 and a gas hose 14 are disposed. The electric cable 13 is a power supply path for supplying power from a welding power source (not shown) to the electrode rod 100. Specifically, power is supplied from the welding apparatus to the electrode rod 100 via the electric cable 13, the conductive portion 12, the collet body 30, and the collet 50.

[0026] The gas hose 14 is a gas supply path for supplying shielding gas to the electrode rod 100. After the shielding gas is supplied from a gas cylinder (not shown) into the welding torch 1 through the gas hose 14, it is supplied to one end side of the electrode rod 100 through the gap between the conductive part 12 and the collet body 30 and the collet 50. The shielding gas is, for example, argon gas. Note that the shielding gas is not limited to argon gas and may be other inert gases such as carbon dioxide gas or helium gas.

[0027] A cap 15 is disposed on the other end side of the torch body 10. The cap 15 is made of an insulating resin member. The cap 15 prevents the other end side of the electrode rod 100 from being exposed from the torch body 10. The cap 15 contacts the other end side of the collet 50 and supports the collet 50.

[0028] An adapter 16 is disposed on one end side of the cover part 11. The adapter 16 is made of an insulating material. The adapter 16 protects a part of one end side of the conductive part 12. The adapter 16 connects the torch body 10 and the jacket 20.

[0029] The jacket 20 is disposed on one end side of the torch body 10. The jacket 20 is connected to the adapter 16 via an O-ring 21 to prevent leakage of the shielding gas. The jacket 20 is made of an insulating material. The jacket 20 covers and protects one end side of the collet body 30.

[0030] The collet body 30 is a cylindrical member having a flange shape. The collet body 30 supports a part of the outer periphery of the collet 50.

[0031] The collet body 30 is made of a conductor. The collet body 30 is mainly composed of copper. The collet body 30 in the present embodiment is made of chromium copper containing chromium in addition to copper.

[0032] The collet body 30 forms part of the heat transfer path for cooling the electrode bar 100. A plurality of through holes for supplying shielding gas to the nozzle 40 are formed on one end side of the collet body 30. Thereby, the collet body 30 is configured such that an inert gas can flow between the collet body 30 and the collet 50.

[0033] A gasket 31 and a sleeve 32 are provided on one end side of the collet body 30. The gasket 31 is a cylindrical member that abuts against the flange portion of the collet body 30 in the axial direction (DR1 direction). The sleeve 32 is a cylindrical member located on one end side of the gasket 31. The gasket 31 and the sleeve 32 are made of an insulating material. Thereby, the collet body 30 and the nozzle 40 are insulated from each other.

[0034] The nozzle 40 is provided at one end of the welding torch 1. The nozzle 40 is screwed into the jacket 20. The nozzle 40 is a portion where the electrode bar 100 protrudes from the inside and shielding gas is jetted around the electrode bar 100. The nozzle 40 is made of a metal material.

[0035] The collet 50 is housed inside the collet body 30. The collet 50 is provided so as to be capable of power supply by contacting the collet body 30 at one end side. The collet 50 forms part of the heat transfer path for cooling the electrode bar 100. Details of the collet 50 will be described later.

[0036] The electrode bar 100 is a portion where an arc is generated at one end side when power is supplied during welding. The electrode bar 100 includes an electrode portion 110 and a cylindrical member 120.

[0037] The electrode portion 110 extends in the axial direction (DR1 direction). The electrode portion 110 is made of, for example, tungsten. Note that the electrode portion 110 is not limited to being made of tungsten, and may be made of a tungsten alloy or other high melting point material.

[0038] The cylindrical member 120 has the electrode portion 110 detachably fitted therein and covers the circumferential surface of the electrode portion 110. The cylindrical member 120 covers the circumferential surface of the electrode portion 110 in a state where one end side of the electrode portion 110 is exposed in a range of 1 cm or more and 2 cm or less in the axial direction (DR1 direction), for example.

[0039] A supported region 121 is provided on a part of the outer circumferential surface of the cylindrical member 120. The supported region 121 is a region that comes into contact with the collet 50. The collet 50 supports the electrode bar 100 in contact with the supported region 121 of the cylindrical member 120 in the axial direction (DR1 direction).

[0040] The cylindrical member 120 is made of a metal having an electrical resistance lower than that of the electrode portion 110. The cylindrical member 120 according to the present embodiment is made of copper, for example. Since the cylindrical member 120 has an electrical resistance lower than that of the electrode portion 110, it has a higher thermal conductivity than the electrode portion 110.

[0041] When the electrode bar 100 is powered and an arc is generated, the electrode bar 100 causes resistive heating. By disposing the cylindrical member 120 on the circumferential surface of the electrode portion 110, the supplied current mainly flows to the cylindrical member 120, so that the resistive heating in the electrode portion 110 is suppressed.

[0042] Next, the configuration of the collet will be described. FIG. 2 is a cross-sectional view showing the configuration around the collet included in the welding torch according to Embodiment 1 of the present invention.

[0043] The collet 50 supports the outer circumference of the electrode bar 100. The collet 50 in the present embodiment supports the outer circumference near the intermediate position of the electrode bar 100 in the first direction (DR1 direction).

[0044] The collet 50 includes a main body portion 150 and a plating layer 160.

[0045] The main body portion 150 is made of a material containing copper as a main component. In the present embodiment, the main body portion 150 is made of chromium copper containing chromium in addition to copper.

[0046] The plating layer 160 covers at least a part of the surface of the main body portion 150. In the present embodiment, the plating layer 160 covers the entire surface of the main body portion 150. From the viewpoint of cost reduction such as masking, it is desirable that the plating layer 160 be arranged to cover the entire surface of the main body portion 150. Note that the plating layer 160 may cover only a part of the main body portion 150. Plating a part of the main body portion 150 can reduce the total amount of plating of the plating layer when the plating layer contains an expensive metal, and thus a low-cost collet can be configured.

[0047] The plating layer 160 is made of a metal different from the material of the main body portion 150. In the present embodiment, the plating layer 160 is made of a metal having a melting point higher than that of the material of the main body portion 150. Specifically, the plating layer 160 is made of a metal having nickel as a main component.

[0048] Nickel has a higher melting point compared to copper. Also, nickel is less expensive and more readily available compared to silver or gold. For this reason, the plating layer 160 having nickel as a main component has high strength compared to copper, and is low-cost and highly versatile.

[0049] The thickness of the plating layer 160 is, for example, not less than several μm and not more than several tens of μm. The plating layer 160 is formed, for example, by electroless plating. Note that since the plating layer 160 is made of a metal having nickel as a main component, it may contain some impurities within a range that maintains the high strength of nickel.

[0050] The plating layer 160 is located on the outer periphery of the collet 50, at least at the portion where the collet body 30 supports the outer periphery of the collet 50. In the present embodiment, since the plating layer 160 is located on the entire surface of the main body 150, the collet body 30 supports the collet 50 via the plating layer 160 regardless of which position on the outer periphery of the collet 50 it supports.

[0051] The collet 50 is fixed while being pressed against the inner peripheral portion of the collet body 30 by the cap 15 in the first direction (DR1 direction). The collet 50 is in contact with the collet body 30 at the contact surface portion 51. Since the materials of the main body 150 of the collet 50 and the collet body 30 are chromium copper, the materials of the main body 150 of the collet 50 and the collet body 30 are composed of the same material.

[0052] Generally, in a state where the same kind of metals are in contact or rubbing against each other (a state of an alloy), from the viewpoint that they have similar strengths to each other, the wear of each of the metals tends to progress. Therefore, if the collet 50 does not include the plating layer 160, the main body 150 of the collet 50 and the collet body 30, which are the same kind of metals, come into contact with each other. As a result, the wear of the main body 150 of the collet 50 and the collet body 30 tends to progress.

[0053] On the other hand, in the present embodiment, the collet 50 includes the plating layer 160, and the main body 150 of the collet 50 is fixed to the collet body 30 with the plating layer 160 of different metals interposed therebetween. As a result, since the wear of each of the metals is suppressed without the same kind of metals coming into contact with each other, the wear of the main body 150 of the collet 50 and the collet body 30 is suppressed.

[0054] In addition, when the welding torch 1 is used at high power, the collet 50 and the collet body 30 may become hot. At this time, if the collet 50 does not include the plating layer 160, the same kind of metals will come into contact at high temperature, and they may stick to each other. However, in the present embodiment, since the main body portion 150 of the collet 50 is fixed to the collet body 30 with the plating layer 160 of dissimilar metals interposed therebetween, the sticking of the collet 50 and the collet body 30 is suppressed.

[0055] Note that the material of the plating layer 160 is not limited to nickel, and it may be hard chromium. Further, when suppressing the state where metals mainly composed of copper as in the present embodiment come into contact with or rub against each other (the state of an alloy), the plating layer may be a metal mainly composed of gold. Also, the plating layer may be zinc, tin, etc. within a range that can withstand the temperature during welding of the welding torch 1.

[0056] Next, the results of the collet fixing tests for the examples and comparative examples according to the present embodiment will be described. Table 1 is a table showing the results of confirming the presence or absence of collet fixing to the collet body with respect to the welding operation time in the examples and comparative examples.

[0057]

Table 1

[0058] In this test, with the welding machine including the welding torch set to the maximum output and arc heating continuously performed, it was confirmed whether the collet was fixed to the collet body at each predetermined operation time of the welding machine.

[0059] As shown in Table 1, in the comparative example, when the operation time of the welding machine elapsed 20 minutes, the collet became fixed to the collet body. On the other hand, in the example, the collet did not become fixed to the collet body until the operation time of the welding machine elapsed at least 100 minutes. As described above, it was confirmed that the durability of the collet body was improved by providing a plating layer on the collet.

[0060] In the welding torch 1 according to Embodiment 1 of the present invention, at least a part of the surface of the main body portion 150 of the collet 50 mainly composed of copper is covered with a plating layer 160 made of a material different from that of the main body portion 150, whereby the durability of the collet body can be improved.

[0061] In the welding torch 1 according to Embodiment 1 of the present invention, since the durability of the collet body is improved, the replacement frequency of the collet 50 can be reduced. Further, in the welding torch 1, since the occurrence of the fixing of the collet 50 to the collet body 30 is suppressed, it is possible to suppress the occurrence of problems such as the collet 50 not coming off from the welding torch 1 due to the fixing and the increase in the labor of component replacement.

[0062] In the welding torch 1 according to Embodiment 1 of the present invention, since the plating layer 160 is made of a metal having a melting point higher than that of the material of the main body portion 150, the main body portion 150 can maintain its material strength even at high temperatures, so that the durability of the collet body mainly composed of copper can be improved.

[0063] In the welding torch 1 according to Embodiment 1 of the present invention, since the plating layer 160 is made of a metal mainly composed of nickel, compared with a plating layer mainly composed of silver or gold, nickel has a high melting point and a low cost. Therefore, the plating layer 160 with high strength and high versatility can improve the durability of the collet body mainly composed of copper.

[0064] In the welding torch 1 according to Embodiment 1 of the present invention, by disposing a plating layer 160 of a dissimilar metal at the position where the main body portion 150 of the collet 50 and the collet body 30 are in contact, the main body portion 150 and the collet body 30 of the collet 50, which are made of the same kind of metal, are in direct contact, and it is possible to prevent a state in which wear easily progresses at the contact portion between the main body portion 150 and the collet body 30 of the collet 50. Therefore, wear of the main body portion 150 of the collet and the collet body 30 can be suppressed.

[0065] (Embodiment 2) Hereinafter, a welding torch according to Embodiment 2 of the present invention will be described with reference to the drawings. Since the configuration of the plating layer of the collet of the welding torch according to Embodiment 2 of the present invention is different from that of the welding torch 1 according to Embodiment 1 of the present invention, the description of the configuration similar to that of the welding torch 1 according to Embodiment 1 of the present invention will not be repeated.

[0066] FIG. 3 is a cross-sectional view showing the configuration of a collet included in the welding torch according to Embodiment 2 of the present invention.

[0067] As shown in FIG. 3, the welding torch 1A according to the present embodiment includes a collet 50A. The collet 50A includes a main body portion 150 and a plating layer 160A.

[0068] The plating layer 160A is made of a metal different from the material of the main body portion 150. The plating layer 160A in the present embodiment is made of a metal having higher thermal conductivity than the material of the main body portion 150. Specifically, the plating layer 160A is made of a metal having silver as a main component.

[0069] Silver has higher thermal conductivity than copper. Therefore, silver has higher heat dissipation than copper. Even when the collet 50A is heated during welding, since the heat dissipation of the collet 50A is high, the durability of the collet body can be improved.

[0070] The plating layer 160A covers at least a part of the surface of the main body 150. In the present embodiment, the plating layer 160A covers the entire surface of the main body 150. From the perspective of cost reduction such as masking, it is desirable that the plating layer 160A be arranged to cover the entire surface of the main body 150. When a plating layer 160A mainly composed of silver is located on the entire surface of the main body 150, since silver has high thermal conductivity, the surface area for dissipating heat during welding can be increased, and the heat dissipation performance of the collet 50A can be enhanced.

[0071] In the welding torch 1A according to the second embodiment of the present invention, since the plating layer 160A is composed of a metal mainly containing silver, the plating layer 160A is composed mainly of silver, which has better thermal conductivity compared to copper and lower cost compared to gold. As a result, even when the arc output increases and the collet 50A is heated, heat can be easily dissipated from the plating layer 160A, and a highly versatile plating layer 160A can be formed, so that the durability of the collet body mainly composed of copper can be improved.

[0072] Note that the electrode rod 100 in each of the above-described embodiments includes a cylindrical member 120 made of copper. Therefore, from the perspective of suppressing a state where the same kind of metals are in contact or rubbing against each other (a eutectic state), it is desirable that the plating layer 160 of the collet 50 be provided not only at the location in contact with the collet body 30 but also at least at the location in contact with the electrode rod 100.

[0073] Also, when comparing the collet body 30 and the collet 50, the collet 50 is more likely to be deformed to support the electrode rod 100. For this reason, it is assumed that the replacement frequency of the collet 50 is higher than that of the collet body 30. By providing the plating layer 160 on the main body 150 of the collet 50 rather than providing the plating layer on the collet body 30, the durability of the collet 50, which is likely to have a higher replacement frequency, can be increased. Thereby, the replacement frequency of the consumables in the welding torch 1 can be reduced.

[0074] In addition, since the collet made of a material mainly composed of iron may require rust prevention, it is assumed that the collet is subjected to a rust prevention plating treatment. On the other hand, since copper has a higher rust prevention function compared to iron, a collet made of a material mainly composed of copper does not require a plating treatment for rust prevention. However, even for a collet made of a material mainly composed of copper as in the present embodiment, the significance of the present invention lies in the fact that a plating layer is provided on the collet body in order to enhance the durability of the collet body.

[0075] It should be noted that the above-described embodiments disclosed this time are illustrative in all respects and do not serve as a basis for a limiting interpretation. Therefore, the technical scope of the present disclosure is not construed only by the above-described embodiments. Also, all changes within the meaning and scope equivalent to the claims are included. In the description of the above-described embodiments, combinable configurations may be combined with each other.

Explanation of Reference Numerals

[0076] 1, 1A Welding torch, 30 Collet body, 50, 50A Collet, 100 Electrode rod, 150 Body part, 160, 160A Plating layer.

Claims

1. An electrode bar, and a collet that supports the outer periphery of the electrode bar, wherein the collet comprises a main body portion made of a material containing copper as a main component, and a plating layer that covers at least a part of the surface of the main body portion and is made of a metal different from the material of the main body portion, a welding torch.

2. The welding torch according to claim 1, wherein the plating layer is made of a metal having a melting point higher than that of the material of the main body portion.

3. The welding torch according to claim 2, wherein the plating layer is made of a metal having nickel as a main component.

4. The welding torch according to claim 1, wherein the plating layer is made of a metal having silver as a main component.

5. further comprising a collet body made of copper as a main component, configured to support a part of the outer periphery of the collet while allowing an inert gas to flow between the collet and the electrode bar, The welding torch according to any one of claims 1 to 4, wherein the plating layer is located at least on the part of the outer periphery of the collet.

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