Welding electrodes and welding torches

Abstract

To replace only an electrode bar and reuse a cylindrical member when the electrode bar has consumed in the electrode bar of which a peripheral surface is coated with the cylindrical member.SOLUTION: A welding electrode comprises an electrode bar 110, and a cylindrical member 120. The electrode bar 110 extends in an axial direction. The cylindrical member 120 is configured from a metal having an electrical resistance lower than a material of the electrode bar 110, and the electrode bar 110 is detachably fitted therein and the cylindrical member covers a peripheral surface of the electrode bar 110. A slit part 122, which penetrates the cylindrical member 120 while extending from one end toward the other end in the axial direction, is formed in the cylindrical member 120.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a welding electrode and a welding torch. [Background technology]

[0002] Japanese Patent Laid-Open Publication No. 2002-316293 (Patent Document 1) is a prior art document disclosing an electrode for metal joining. The electrode for metal joining described in Patent Document 1 includes a center electrode and a conductor portion. The center electrode is made of a material having a higher electrical resistance than the conductor portion. The conductor portion is coated on the surface of the center electrode by any of shrink fitting, forging, thermal spraying, casting, and brazing. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-316293 Summary of the Invention [Problem to be solved by the invention]

[0004] In the metal joining electrode described in Patent Document 1, the conductor portion covering the electrode rod is joined to the electrode rod and integrated with it, so when the electrode rod wears out, it needs to be replaced with an electrode rod covered by the conductor portion; the electrode rod cannot be replaced alone.

[0005] The present invention has been made to solve the above-mentioned problems, and aims to provide a welding electrode and a welding torch in which the outer surface of an electrode rod is covered by a cylindrical member, and when the electrode rod becomes worn, only the electrode rod can be replaced and the cylindrical member can be reused. [Means for solving the problem]

[0006] A welding electrode according to the present invention comprises an electrode rod and a tubular member. The electrode rod extends in an axial direction. The tubular member is made of a metal having a lower electrical resistance than the material of the electrode rod, and the electrode rod is removably fitted into the tubular member to cover the circumferential surface of the electrode rod. The tubular member has a slit extending from one end to the other end in the axial direction and penetrating the tubular member.

[0007] As a result, when the electrode rod, the circumferential surface of which is covered by the cylindrical member, wears out, only the electrode rod can be replaced and the cylindrical member can be reused.

[0008] In one embodiment of the present invention, the slit portion is formed in a linear shape.

[0009] In this case, the slits can be easily formed, and the width of the slits can be easily expanded in the circumferential direction of the cylindrical member, making it easier to attach and detach the electrode rods to and from the cylindrical member.

[0010] In one embodiment of the present invention, the slit portion is formed in a spiral shape.

[0011] In this case, the heat of the electrode rod can be uniformly transferred to the entire periphery of the cylindrical member.

[0012] In one embodiment of the present invention, the slit portion is formed continuously from one end to the other end.

[0013] In this case, the width of the slit portion can be expanded in the circumferential direction of the cylindrical member over the entire length of the cylindrical member in the axial direction, making it easier to attach and detach the electrode rod from the cylindrical member.

[0014] A welding torch according to the present invention includes the above-described welding electrode and a collet. The collet supports the welding electrode by contacting the supported region of the cylindrical member in the axial direction. The slit portion is formed continuously in the axial section from one end to the supported region.

[0015] In this case, by ensuring the contact area between the collet and the cylindrical member of the welding electrode, an increase in contact resistance between the collet and the cylindrical member can be suppressed. [Effects of the Invention]

[0016] According to the present invention, in an electrode rod whose circumferential surface is covered by a cylindrical member, when the electrode rod becomes worn, only the electrode rod can be replaced and the cylindrical member can be reused. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a cross-sectional view showing the configuration of a welding torch according to a first embodiment of the present invention. [Figure 2] 1 is a perspective view showing a configuration of a welding electrode according to a first embodiment of the present invention. [Figure 3] 3 is a cross-sectional view of the welding electrode of FIG. 2 as seen from the direction of the arrows along line III-III. [Figure 4] 4 is a cross-sectional view of the welding electrode of FIG. 2 as viewed from the direction of the arrows along line IV-IV. [Figure 5] FIG. 10 is a perspective view showing the configuration of the periphery of a welding electrode provided in a welding torch according to a second embodiment of the present invention. [Figure 6] FIG. 10 is a perspective view showing the configuration of a welding electrode according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, welding electrodes and welding torches according to embodiments 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 will be given the same reference numerals, and the description thereof will not be repeated.

[0019] In the drawings, the axial direction in which the electrode rod and the cylindrical member extend is referred to as the DR1 direction. In the axial direction (DR1 direction), the pointed side of the electrode rod is referred to as one end side, and the opposite side is referred to as the other end side.

[0020] (Embodiment 1) First, the structure of the welding torch will be described. Fig. 1 is a cross-sectional view showing the configuration of a welding torch according to a first embodiment of the present invention. As shown in Fig. 1, welding torch 1 according to the first embodiment of the present invention is used for, for example, TIG (Tungsten Inert Gas) welding.

[0021] The welding torch 1 according to this embodiment includes a torch body 10, a jacket 20, a collet body 30, a nozzle 40, a collet 50, and a welding electrode 100.

[0022] The torch body 10 is connected to a torch handle (not shown) and includes a cover portion 11 and a conductive portion 12.

[0023] The cover portion 11 is made of an insulating resin material. The cover portion 11 protects the conductive portion 12. The conductive portion 12 is disposed inside the cover portion 11. The inner peripheral surface of the conductive portion 12 is in contact with the collet body 30. The conductive portion 12 is connected to a water-cooled or air-cooled cooling mechanism (not shown). The conductive portion 12 forms part of a heat transfer path for cooling the welding electrode 100.

[0024] An electric cable 13 and a gas hose 14 are arranged inside cover 11. Electric cable 13 is a power supply path for supplying power from a welding power source (not shown) to welding electrode 100. Specifically, power is supplied from the welding device to welding electrode 100 via electric cable 13, conductive part 12, collet body 30, and collet 50.

[0025] The gas hose 14 is a gas supply path for supplying shielding gas to the welding electrode 100. The shielding gas is supplied from a gas cylinder (not shown) through the gas hose 14 into the welding torch 1, and then supplied to one end of the welding electrode 100 through the conductive portion 12 and the gap between 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.

[0026] A cap 15 is disposed on the other end of the torch body 10. The cap 15 is made of an insulating resin material. The cap 15 prevents the other end of the welding electrode 100 from being exposed from the torch body 10. The cap 15 contacts the other end of the collet 50 and supports the collet 50.

[0027] An adapter 16 is disposed on one end of the cover portion 11. The adapter 16 is made of an insulating material. The adapter 16 protects a portion of the one end of the conductive portion 12. The adapter 16 connects the torch body 10 and the jacket 20.

[0028] The jacket 20 is disposed on one end 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 of the collet body 30.

[0029] The collet body 30 is a cylindrical member having a flange shape. The collet body 30 is made of a conductor, for example, copper. The collet body 30 forms part of a heat transfer path for cooling the welding electrode 100. One end of the collet body 30 is formed with a plurality of through holes for supplying shielding gas to the nozzle 40.

[0030] 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 that is located on one end side of the gasket 31. The gasket 31 and the sleeve 32 are made of an insulating material. This insulates the collet body 30 from the nozzle 40.

[0031] The nozzle 40 is provided at one end of the welding torch 1. The nozzle 40 is screwed into the jacket 20. The welding electrode 100 protrudes from the inside of the nozzle 40, and the nozzle 40 is a part from which the shielding gas is sprayed around the welding electrode 100. The nozzle 40 is made of a metal material.

[0032] The collet 50 is housed inside the collet body 30. The collet 50 is made of a conductive material, for example, copper. The collet 50 is provided so that power can be supplied by contacting one end side with the collet body 30. The collet 50 forms part of a heat transfer path for cooling the welding electrode 100.

[0033] Next, a description will be given of the welding electrode 100. Fig. 2 is a perspective view showing the configuration of the welding electrode according to the first embodiment of the present invention. Fig. 3 is a cross-sectional view of the welding electrode of Fig. 2, seen from the direction of the arrows III-III. Fig. 4 is a cross-sectional view of the welding electrode of Fig. 2, seen from the direction of the arrows IV-IV.

[0034] The welding electrode 100 is a part where an arc is generated at one end when power is supplied during welding. As shown in FIGS.

[0035] The electrode rod 110 extends in the axial direction (DR1 direction). The electrode rod 110 according to this embodiment has a conical tip portion 111 on one end side.

[0036] The electrode rod 110 is made of, for example, tungsten. However, the electrode rod 110 is not limited to being made of tungsten, and may be made of a tungsten alloy or other high-melting-point materials.

[0037] 4, the outer diameter D1 of the electrode rod 110 is, for example, 3.2 mm. The outer diameter D1 of the electrode rod 110 may be larger than the inner diameter D2 of the cylindrical member 120, which will be described later. The outer diameter D1 is preferably 0.5 mm or more and 6.4 mm or less.

[0038] The electrode bar 110 is detachably fitted into the cylindrical member 120, covering the circumferential surface of the electrode bar 110. The cylindrical member 120 covers at least half of the circumferential surface of the electrode bar 110 in the circumferential direction in order to fix the electrode bar 110 and the cylindrical member 120 to each other. The cylindrical member 120 covers the circumferential surface of the electrode bar 110 in a state where, for example, one end of the electrode bar 110 is exposed over a range of 1 cm to 2 cm in the axial direction (DR1 direction).

[0039] 1 and 2, cylindrical member 120 has a supported region 121 provided on a portion of its outer circumferential surface. Supported region 121 is a region that comes into contact with collet 50. Collet 50 comes into contact with supported region 121 of cylindrical member 120 in the axial direction (DR1 direction) to support welding electrode 100.

[0040] The cylindrical member 120 is made of a metal having a lower electrical resistance than the material of the electrode rod 110. The cylindrical member 120 according to this embodiment is made of, for example, copper. Since the cylindrical member 120 has a lower electrical resistance than the material of the electrode rod 110, it has a higher thermal conductivity than the electrode rod 110. Note that the cylindrical member 120 is not limited to being made of copper, and may be made of a copper alloy, aluminum, an aluminum alloy, or the like.

[0041] 4, the inner diameter D2 of the cylindrical member 120 is, for example, 3.2 mm. When the electrode rod 110 is fitted into the cylindrical member 120, the inner diameter D2 of the cylindrical member 120 and the outer diameter D1 of the electrode rod 110 are the same diameter. Before the electrode rod 110 is fitted into the cylindrical member 120, the inner diameter D2 of the cylindrical member 120 is smaller than 3.2 mm.

[0042] The outer diameter of the cylindrical member 120 is, for example, 4.8 mm. The outer diameter of the cylindrical member 120 is set within a range that allows the cylindrical member 120 to sufficiently absorb the heat generated by the electrode rod 110 during welding.

[0043] 2 and 4, a slit portion 122 is formed in the cylindrical member 120, extending from one end to the other end in the axial direction (DR1 direction) and penetrating the cylindrical member 120. One slit portion 122 is formed in the cylindrical member 120 according to this embodiment. The number of slit portions 122 is not limited.

[0044] The slit portion 122 is formed linearly. The slit portion 122 is formed continuously from one end to the other end in the axial direction (DR1 direction). The slit portion 122 is formed by, for example, laser processing.

[0045] 4, the circumferential width W of the slit portion 122 is, for example, 1 mm. However, the width W is not limited to 1 mm. It is desirable that the width W be as narrow as possible. This increases the contact area between the cylindrical member 120 and the electrode rod 110, making it easier to transfer heat generated by the electrode rod 110 during welding to the cylindrical member 120.

[0046] When current is supplied to the welding electrode 100 and an arc is generated, the welding electrode 100 generates resistance heat. Specifically, the electrode rod 110, which has a higher electrical resistance than the cylindrical member 120, mainly generates resistance heat. By arranging the cylindrical member 120 on the circumferential surface of the electrode rod 110, the supplied current flows mainly to the cylindrical member 120, thereby suppressing resistance heat generation in the electrode rod 110.

[0047] Furthermore, because the cylindrical member 120 has a higher thermal conductivity than the electrode rod 110, even if the electrode rod 110 generates heat, the heat can be transferred from the electrode rod 110 to the collet 50 via the cylindrical member 120. This allows the heat generated in the electrode rod 110 during welding to be efficiently cooled. By providing the cylindrical member 120 to the welding electrode 100, resistance heating of the electrode rod 110 can be suppressed, thereby suppressing evaporation of the electrode rod 110, thereby extending the life of the welding electrode 100.

[0048] Next, the attachment and detachment of the electrode rod 110 and the cylindrical member 120 of the welding electrode 100 will be described.

[0049] When the electrode bar 110 is attached to the cylindrical member 120, the electrode bar 110 is fitted into the cylindrical member 120 from the axial direction (DR1 direction). At this time, because the outer diameter D1 of the electrode bar 110 is larger than the inner diameter of the cylindrical member 120, the inner diameter of the cylindrical member 120 is expanded radially while the electrode bar 110 is fitted into the cylindrical member 120. This allows the width W of the slit portion 122 to expand in the circumferential direction, so that the cylindrical member 120 covers the electrode bar 110 while elastically deforming in the circumferential direction.

[0050] When removing the electrode rod 110 from the cylindrical member 120, for example, the electrode rod 110 can be removed from the cylindrical member 120 by hitting the electrode rod 110 from the other end side with a hammer or the like. The cylindrical member 120 is provided with the slit portion 122, which fixes the electrode rod 110 in a state in which the electrode rod 110 is elastically deformed relative to the electrode rod 110. Therefore, the electrode rod 110 can be moved more easily in the axial direction (DR1 direction) than when the electrode rod 110 is joined to the cylindrical member 120 by shrink fitting or the like.

[0051] If one end of the electrode rod 110 becomes shorter due to evaporation caused by high temperatures during welding, the electrode rod 110 can be removed from the tubular member 120 and re-ground. After the electrode rod 110 has been re-ground, the length of the electrode rod 110's extension relative to the tubular member 120 can be adjusted and the electrode rod 110 can be re-attached to the tubular member, allowing the tubular member 120 to be reused. Reusing the tubular member 120 reduces the amount of tubular member 120 used compared to when the electrode rod 110 and the tubular member 120 are used together, thereby reducing the material costs of the welding electrode 100. Furthermore, because the electrode rod 110 and the tubular member 120 can be handled separately, the welding electrode 100 can be easily disposed of.

[0052] In the welding electrode 100 and welding torch 1 according to the first embodiment of the present invention, the slit portion 122 is formed in the tubular member 120, so that the tubular member 120 can fix and cover the electrode rod 110 while elastically deforming in the circumferential direction. Therefore, in the case of the electrode rod 110 whose circumferential surface is covered by the tubular member 120, when the electrode rod 110 becomes worn, only the electrode rod 110 can be replaced and the tubular member 120 can be reused.

[0053] In the welding electrode 100 and welding torch 1 according to the first embodiment of the present invention, the slit portion 122 is formed linearly in the axial direction (DR1 direction), which makes it possible to easily form the slit portion 122 and also to easily expand the width W of the slit portion 122 in the circumferential direction of the tubular member 120, thereby making it easy to attach and detach the electrode rod 110 to and from the tubular member 120.

[0054] In the welding electrode 100 and welding torch 1 according to embodiment 1 of the present invention, the slit portion 122 is formed continuously from one end to the other in the axial direction (DR1 direction), so that the width W of the slit portion 122 can be expanded in the circumferential direction of the tubular member 120 over the entire length of the tubular member 120 in the axial direction (DR1 direction), thereby making it easier to attach and detach the electrode rod 110 to and from the tubular member 120.

[0055] (Embodiment 2) A welding electrode and a welding torch according to a second embodiment of the present invention will be described below with reference to the drawings. The welding electrode and the welding torch according to the second embodiment of the present invention differ from welding electrode 100 and welding torch 1 according to the first embodiment of the present invention in the configuration of the cylindrical member, and therefore, the description of the configuration that is the same as that of welding electrode 100 and welding torch 1 according to the first embodiment of the present invention will not be repeated.

[0056] 5 is a perspective view showing the configuration of the vicinity of a welding electrode provided in a welding torch according to embodiment 2 of the present invention. As shown in FIG. 5, welding torch 1A according to embodiment 2 of the present invention includes collet 50 and welding electrode 200.

[0057] The welding electrode 200 includes an electrode rod 110 and a cylindrical member 220. A supported region 221 is provided on a portion of the outer circumferential surface of the cylindrical member 220. The collet 50 contacts the supported region 221 and supports the welding electrode 200.

[0058] In the cylindrical member 220, a slit portion 222 is formed continuously in a section from one end to the supported region 221 in the axial direction (DR1 direction).

[0059] When the electrode bar 110 is attached to the cylindrical member 220, the electrode bar 110 is fitted into the cylindrical member 220 from the axial direction (DR1 direction). In the portion of the cylindrical member 220 where the slit portions 222 are not provided, the electrode bar 110 is fitted into the cylindrical member 220 in a press-fit state. In the portion of the cylindrical member 220 where the slit portions 222 are provided, the width of the slit portions 222 can be expanded in the circumferential direction by fitting the electrode bar 110, so that the cylindrical member 220 covers and fixes the electrode bar 110 in a state where it is elastically deformed in the circumferential direction.

[0060] When removing the electrode rod 110 from the cylindrical member 220, for example, the electrode rod 110 can be removed from the cylindrical member 220 by hitting the electrode rod 110 from the other end side with a hammer or the like.

[0061] In the welding electrode 200 and welding torch 1A according to embodiment 2 of the present invention, the slit portion 222 is formed continuously in the axial direction (DR1 direction) from one end to the supported region 221, thereby ensuring a sufficient contact area between the collet 50 and the tubular member 220 of the welding electrode 200, thereby suppressing an increase in contact resistance between the collet 50 and the tubular member 220.

[0062] (Embodiment 3) A welding electrode and a welding torch according to a third embodiment of the present invention will be described below with reference to the drawings. The welding electrode and the welding torch according to the third embodiment of the present invention differ from welding electrode 100 and welding torch 1 according to the first embodiment of the present invention in the configuration of the cylindrical member, and therefore, the description of the configuration that is the same as that of welding electrode 100 and welding torch 1 according to the first embodiment of the present invention will not be repeated.

[0063] 6 is a perspective view showing the configuration of a welding electrode according to embodiment 3 of the present invention. As shown in FIG. 6, welding torch 1B according to embodiment 3 of the present invention includes welding electrode 300.

[0064] The welding electrode 300 according to this embodiment includes an electrode rod 110 and a cylindrical member 320. A supported region 321 is provided on a portion of the outer circumferential surface of the cylindrical member 320. As a result, a collet (not shown) comes into contact with the supported region 321 to support the welding electrode 300.

[0065] The cylindrical member 320 is formed with a slit portion 322 that extends from one end to the other end in the axial direction (DR1 direction) and penetrates the cylindrical member 320. The cylindrical member 320 according to this embodiment has one slit portion 322 formed therein.

[0066] The slits 322 are formed in a spiral shape. The slits 322 are formed continuously from one end to the other in the axial direction (DR1 direction). The spiral slits 322 are uniformly arranged on the circumferential surface of the electrode rod 110 along the axial direction (DR1 direction) without being biased in one direction in the circumferential direction.

[0067] The spirally formed slit portion 322 allows the cylindrical member 320 to deform in the axial direction (DR1 direction) like a coil spring. Even if the electrode rod 110 becomes hot due to resistance heating during welding and a difference in the axial length (DR1 direction) of the electrode rod 110 and the cylindrical member 320 occurs due to a difference in linear expansion coefficient, the cylindrical member 320 can deform in the axial direction (DR1 direction), making it easier for the cylindrical member 320 to follow the electrode rod 110.

[0068] In the welding electrode 300 and welding torch 1B according to the third embodiment of the present invention, the slit portion 322 is formed spirally in the axial direction (DR1 direction), so that the heat generated in the electrode rod 110 during welding can be uniformly transmitted to the entire circumference of the tubular member 320.

[0069] Although the welding electrodes and welding torches according to the embodiments of the present invention are described with reference to TIG (Tungsten Inert Gas) welding, the application of the present invention is not limited to welding devices for TIG welding. The present invention can also be applied to other non-consumable electrode welding methods, such as plasma arc welding.

[0070] It should be noted that the above-described embodiments disclosed herein are illustrative in all respects and are not intended to be limiting. Therefore, the technical scope of the present disclosure should not be interpreted solely by the above-described embodiments. Furthermore, all modifications within the scope and meaning equivalent to the claims are included. In the description of the above-described embodiments, combinable configurations may be combined with each other. [Explanation of symbols]

[0071] 1,1A,1B welding torch, 50 collet, 100,200,300 welding electrode, 110 electrode rod, 120,220,320 tubular member, 121,221,321 supported area, 122,222,322 slit portion.

Claims

1. A welding electrode supported by a collet, an electrode rod extending in the axial direction; a cylindrical member made of a metal having a lower electrical resistance than the material of the electrode rod, the cylindrical member having the electrode rod detachably fitted therein and covering the peripheral surface of the electrode rod; The welding electrode has a slit formed in the cylindrical member, the slit extending from one end to the other end in the axial direction and penetrating the cylindrical member.

2. The welding electrode according to claim 1 , wherein the slit portion is formed linearly.

3. The welding electrode according to claim 1 , wherein the slit portion is formed in a spiral shape.

4. The welding electrode according to claim 1 , wherein the slit portion is formed continuously from the one end to the other end.

5. The welding electrode according to any one of claims 1 to 3; the collet contacting the supported region of the cylindrical member in the axial direction to support the welding electrode, A welding torch, wherein the slit portion is formed continuously in the axial direction from the one end to the supported region.

Images