Welding torch

Abstract

To improve cooling performance while securing durability on a welding torch with a tip of which direction can be changed.SOLUTION: A welding torch 1 includes: a body part 10 including an electrode bar 11 and a cylindrical part for supporting the electrode bar; a cooling part 30 provided with a flow channel for a cooling fluid therein; a flexible part 20 that connects the body part 10 and the cooling part 30 to each other and has flexibility; and a flexible heat pipe 23 installed to the flexible part 20, having flexibility, and coming into contact with each of the cylindrical part and the cooling part 30.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] Conventionally, in the TIG (Tungsten Inert Gas) welding method using a welding torch equipped with a non-consumable electrode rod, a high-temperature arc is generated between the base material and the electrode rod made of tungsten, and the base material and the welding material are melted by the heat of this arc.

[0003] In this welding torch, from the viewpoint of improving workability, it is required that the direction of the tip of the welding torch be configured to be flexibly changeable. As a document disclosing such a welding torch, for example, there is Japanese Patent Laid-Open No. 4-274880 (Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the TIG welding method, due to being exposed to the above-mentioned high-temperature arc and the generation of Joule heat in the electrode rod, the tip side portion of the welding torch becomes high temperature. Therefore, if no countermeasure is taken against this, the tip side portion of the welding torch may be burned out, and as a result, an increase in the large current of the welding torch may be hindered.

[0006] Thus, from the viewpoint of increasing the welding current of the welding torch, it is required that the tip side portion of the welding torch be efficiently cooled. If a cooling pipe through which cooling water or the like circulates inside can be arranged to reach the tip side portion of the welding torch, efficient cooling of the said portion becomes possible. However, in the welding torch configured to be able to flexibly change the direction of the tip as described above, it is not easy to arrange the cooling pipe so as to reach the tip side portion thereof.

[0007] In this regard, in Patent Document 1 mentioned above, a cooling pipe formed in a spiral shape so as to be bendable is arranged so as to reach the tip side portion of the welding torch. As a result, it is a welding torch that can flexibly change the direction of the tip and can efficiently cool the tip side portion. However, when configured in this way, there is a problem that the risk of breakage of the cooling pipe increases due to an increase in the number of bends of the cooling pipe.

[0008] Therefore, the present invention has been made in view of the above points, and an object thereof is to improve the cooling performance while ensuring durability in a welding torch configured to be able to change the direction of the tip.

Means for Solving the Problems

[0009] The welding torch according to the present invention includes an electrode rod, a main body portion having a cylindrical portion that supports the electrode rod, a cooling portion provided with a flow path for a cooling fluid inside, a flexible portion that connects the main body portion and the cooling portion to each other, and a flexible heat pipe provided on the flexible portion and having flexibility and contacting each of the cylindrical portion and the cooling portion.

[0010] By configuring in this way, it becomes possible to efficiently transport the heat generated in the tip side portion of the welding torch to the cooling portion via the flexible heat pipe. As a result, the cooling efficiency of the tip side portion of the welding torch including the electrode rod can be dramatically improved.

[0011] Also, by configuring it in this way, it becomes unnecessary to arrange the flow path of the cooling fluid so as to cross the flexible part. Therefore, in a welding torch configured to be able to change the direction of the tip, it is possible to improve the cooling performance while ensuring durability.

[0012] In the welding torch according to the present invention, it is preferable that the flexible heat pipe includes a wound portion wound around the flexible part.

[0013] By configuring it in this way, the wound portion becomes a so-called play when the flexible heat pipe deforms following the flexible part, so that the load on the flexible heat pipe during the deformation can be reduced.

[0014] In the welding torch according to the present invention, the cylindrical portion includes a collet that supports the electrode bar, a collet body that contacts the outer periphery of the collet, and a conductive portion that contacts the outer periphery of the collet body. In that case, the flexible heat pipe may be in contact with the conductive portion of the cylindrical portion.

[0015] By configuring it in this way, the heat of the conductive portion that has become high temperature can be efficiently transported to the cooling portion, and as a result, the portion on the tip side of the welding torch can be efficiently cooled.

Effects of the Invention

[0016] According to the present invention, in a welding torch configured to be able to change the direction of the tip, it is possible to improve the cooling performance while ensuring durability.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Best Mode for Carrying Out the Invention

[0018] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The following embodiments exemplify the case where the present invention is applied to a welding torch used for TIG welding as an example of a welding torch. In the following embodiments, the same or common parts are denoted by the same reference numerals in the drawings, and the description thereof will not be repeated.

[0019] (Embodiment) FIG. 1 is a schematic view of a welding torch according to an embodiment. FIG. 2 is a schematic view enlarging the vicinity of the main body portion of the welding torch shown in FIG. 1. FIG. 3 is a schematic view enlarging the vicinity of the cooling portion of the welding torch shown in FIG. 1. Hereinafter, the welding torch 1 according to the present embodiment will be described with reference to FIGS. 1 to 3.

[0020] As shown in FIGS. 1 to 3, the welding torch 1 includes a main body portion 10 having an electrode rod 11 and the like to be described later, a flexible portion 20, and a cooling portion 30. The main body portion 10, the flexible portion 20, and the cooling portion 30 are arranged in this order from the tip side of the welding torch 1.

[0021] The main body portion 10 defines the tip-side portion of the welding torch 1. The flexible portion 20 connects the main body portion 10 and the cooling portion 30 to each other. The cooling portion 30 is a part for cooling the main body portion 10.

[0022] The main body portion 10 has an electrode rod 11, a collet 12, a collet body 13, a conductive portion 14, a first cover portion 15, a nozzle 16, and a torch body 17.

[0023] The electrode rod 11 is a part that generates an arc between the tip of the electrode rod 11 and the base material when power is supplied thereto.

[0024] The electrode rod 11 is made of, for example, tungsten. Note that the electrode rod 11 is not particularly limited to being made of tungsten, and may be made of a tungsten alloy or other high melting point material.

[0025] The collet 12 is a portion having a substantially cylindrical shape. At the tip of the collet 12, a gripping portion 12a is provided whose inner diameter is larger than the diameter of the electrode rod 11 when the collet 12 is not assembled to the welding torch 1. The collet 12 is configured such that the inner diameter of the gripping portion 12 in the state where it is assembled to the welding torch 1 is reduced compared to the inner diameter of the gripping portion 12a in the state where it is not assembled to the welding torch 1. The electrode rod 11 is gripped by the gripping portion 12a in this reduced diameter state. Thereby, the electrode rod 11 is supported by the collet 12.

[0026] The collet body 13 is a portion having a substantially cylindrical shape. The collet body 13 is externally inserted into the collet 12. Thereby, the collet body 13 is in contact with the outer periphery of the collet 12. A plurality of through holes for supplying shielding gas to the nozzle 16 are formed at the tip of the collet body 13.

[0027] The conductive portion 14 is a portion having a substantially cylindrical shape. The tip side portion of the conductive portion 14 is externally inserted into the collet body 13. Thereby, the conductive portion 14 is in contact with the outer periphery of the collet body 13.

[0028] A plurality of convex portions are provided on the inner peripheral surface of the end portion of the conductive portion 14 on the flexible portion 20 side. These convex portions are fitted into the concave portions of the torch body 17 described later.

[0029] The collet 12, the collet body 13, and the conductive portion 14 are made of a conductive material such as copper or a copper alloy, for example.

[0030] In the present embodiment, the collet 12, the collet body 13, and the conductive portion 14 constitute a cylindrical portion that supports the electrode rod 11.

[0031] The first cover portion 15 is an insulating part having a substantially cylindrical shape. Most of the cylindrical portion is disposed inside the first cover portion 15. Thereby, the cylindrical portion is protected by the first cover portion 15. The first cover portion 15 is made of an insulating material such as resin.

[0032] The nozzle 16 is a part having a substantially cylindrical shape. One end of the nozzle 16 is fixed to the tip-side portion of the first cover portion 15 by screwing therewith. Thereby, the other end of the nozzle 16 defines a part of the tip-side portion of the main body portion 10.

[0033] The electrode bar 11 is disposed so as to protrude from an opening provided at the other end of the nozzle 16. The shielding gas is jetted from the tip of the nozzle 16 in a rectified state by passing through the space inside the nozzle 16.

[0034] The nozzle 16 is made of, for example, a metal material. A cylindrical gasket made of an insulating material is interposed between the nozzle 16 and the tip of the collet body 13 in the radial direction of the nozzle 16. Thereby, the nozzle 16 and the collet body 13 are insulated from each other.

[0035] The torch body 17 is a substantially columnar part positioned so as to be interposed between the electrode bar 11 and a flexible part 20 described later in the axial direction of the electrode bar 11. The end of the torch body 17 on the side opposite to the electrode bar 11 side is connected to a coil element 21 of the flexible part 20 described later. The torch body 17 is made of a metal material such as copper or a copper alloy, for example.

[0036] A plurality of recesses are provided on the circumferential surface of the torch body 17. The convex portions of the conductive portion 14 described above are fitted into these recesses, whereby the conductive portion 14 is fixed to the torch body 17.

[0037] The flexible part 20 has a coil element 21 and a second cover part 22. The coil element 21 is a member configured to be bendable by having flexibility. The coil element 21 is made of, for example, copper or a copper alloy. The second cover part 22 is a substantially cylindrical member that protects the coil element 21 by being extrapolated to the coil element 21. The second cover part 22 has flexibility and is made of an insulating material such as resin. The flexible part 20 constituted by the coil element 21 and the second cover part 22 has flexibility as a whole.

[0038] One end of the flexible part 20 is connected to the torch body 17 of the main body part 10, and the other end is connected to a connection part 33 (to be described later) of the cooling part 30. Thereby, the flexible part 20 connects the main body part 10 and the cooling part 30 to each other.

[0039] The flexible part 20 is configured to be bendable. When the flexible part 20 is bent, it becomes possible to flexibly change the direction of the tip side portion (that is, the main body part 10) of the welding torch 1.

[0040] Here, a flexible heat pipe 23 is further provided in the flexible part 20, which will be described in detail later.

[0041] The cooling part 30 has a cooling pipe 31, a third cover part 32, and a connection part 33. A part of the cooling pipe 31 is arranged inside the third cover part 32.

[0042] The cooling pipe 31 is a part that defines the flow path of the cooling fluid. The cooling pipe 31 includes an outgoing pipe that defines a flow path (i.e., the outgoing path of the cooling fluid) for sending out the cooling fluid stored in a tank (not shown) to the vicinity of the connection part 33, and a return pipe that defines a flow path (i.e., the return path of the cooling fluid) for sending back the cooling fluid sent out to the vicinity of the connection part 33 toward the above-mentioned tank. In FIGS. 1 and 3, only the outgoing pipe of this pair of pipes appears.

[0043] In the present embodiment, water is used as the cooling fluid. Note that the cooling fluid is not particularly limited to water and can be variously changed.

[0044] The third cover part 32 is a substantially cylindrical member that defines a part of the internal space of the above-described cooling part 30. The connection part 33 is a substantially columnar part that is positioned so as to be interposed between the flexible part 20 and the end part on the flexible part 20 side of the cooling pipe 31 in the axial direction of the flexible part 20. The end part on the flexible part 20 side of the connection part 33 is connected to the coil element 21 of the flexible part 20.

[0045] The cooling pipe 31 is made of, for example, copper or a copper alloy. Note that the material of the cooling pipe 31 is not particularly limited to copper or the like, and may be, for example, brass or the like. The third cover part 32 and the connection part 33 are made of a metal material such as copper or a copper alloy.

[0046] An electric cable and a gas hose (not shown) are arranged in the inner space defined by the first cover part 15 of the main body part 10, the second cover part 22 of the flexible part 20, and the third cover part 32 of the cooling part 30.

[0047] The electric cable defines a part of the power supply path for supplying power from a welding power source (not shown) to the electrode bar 11. More specifically, the electricity of the welding power source is supplied to the electrode bar 11 via the electric cable, the conductive part 14, the collet body 13, and the collet 12.

[0048] The gas hose defines a part of a gas supply path for supplying shielding gas around the tip of the electrode rod 11. More specifically, after the shielding gas is supplied from a gas cylinder (not shown) through the gas hose into the inside of the welding torch 1, it is supplied around the tip of the electrode rod 11 through the gap between the conductive part 14 and the collet body 13 and the collet 12. The shielding gas is, for example, argon gas. Note that the shielding gas is not particularly limited to argon gas and may be an inert gas such as carbon dioxide gas or helium gas.

[0049] A flexible heat pipe 23 having flexibility is provided in the flexible part 20 described above. More specifically, the flexible heat pipe 23 is routed along the outer periphery of the coil element 21 so that most of it extends along the extending direction of the flexible part 20. One end of the flexible heat pipe 23 is in contact with the outer periphery of the conductive part 14 of the main body part 10. The other end of the flexible heat pipe 23 is in contact with the outer periphery of the cooling pipe 31 of the cooling part 30.

[0050] The flexible heat pipe 23 is a flexible heat pipe formed in a sheet shape. The flexible heat pipe 23 is one in which a condensable fluid is enclosed as a working fluid inside a sealed container (container) having a vacuum-degassed sheet-shaped outer shape. A capillary structure is formed on the inner wall of the container. The container is made of, for example, copper or a copper alloy. As the working fluid, for example, pure water or a refrigerant is used.

[0051] In the flexible heat pipe 23 configured as described above, the working fluid evaporated at one end flows to the other end and dissipates heat, thereby performing heat transport as the latent heat of the working fluid. More specifically, heat emitted from the article to be cooled is transferred to one end of the flexible heat pipe 23, causing the working fluid in the liquid phase state to evaporate at that one end. The generated vapor is moved to the other end side of the flexible heat pipe 23. This vapor returns to the liquid phase state by being cooled at the other end. The working fluid that has returned to the liquid phase state is moved to the one end side of the flexible heat pipe 23 by capillary action due to the capillary structure. Through the phase change and movement of the working fluid described above, instantaneous heat transfer through the flexible heat pipe 23 is performed. Therefore, the flexible heat pipe 23 has a higher thermal conductivity than metal materials such as copper. In FIGS. 1 to 3, for the convenience of drawing, the detailed structure of the flexible heat pipe 23 is not shown.

[0052] The flexible heat pipe 23 includes a wound portion 23a wound around the coil element 21 of the flexible portion 20. In the present embodiment, the flexible heat pipe 23 includes one wound portion 23a wound around the coil element 21 so as to rotate once along the circumferential direction of the coil element 21. Note that the number of wound portions 23a is not particularly limited to one, and a plurality may be used.

[0053] When the coil element 21 is bent from its normal shape (i.e., the shape in the non-bent state), the wound portion 23a deforms so as to spread in the extending direction of the coil element 21. Thereby, the wound portion 23a becomes a so-called play when the flexible heat pipe 23 deforms following the coil element 21. Therefore, the load on the flexible heat pipe 23 during the deformation can be reduced.

[0054] By configuring as described above, in the welding torch 1 configured to be able to change the direction of the tip, it is possible to improve the cooling performance while ensuring durability.

[0055] That is, in the welding torch 1 according to the present embodiment, when a high-temperature arc is generated between the electrode rod 11 and the base material by supplying power to the electrode rod 11, the electrode rod 11 becomes hot. More specifically, in the electrode rod 11, Joule heat is generated and it is exposed to the high-temperature arc, so that it becomes hot during welding. Further, the thermal energy of the electrode rod 11 that has become hot is sequentially transferred to the collet 12, the collet body 13, and the conductive part 14, which are cylindrical parts that support the electrode rod 11, so that these also become hot.

[0056] Here, in the welding torch 1 according to the present embodiment, as described above, the flexible heat pipe 23 having excellent thermal conductivity and flexibility is provided in the flexible part 20 so as to be in contact with each of the conductive part 14 constituting the cylindrical part and the cooling pipe 31 of the cooling part 30.

[0057] By configuring in this way, it becomes possible to efficiently transport the heat generated in the tip side portion of the welding torch 1 to the cooling part 30 via the flexible heat pipe 23. As a result, the cooling efficiency of the tip side portion of the welding torch 1 including the electrode rod 11 can be dramatically improved.

[0058] Further, in the welding torch 1 according to the present embodiment, since the main body part 10 is connected to the flexible part 20 having flexibility, the direction of the main body part 10 can be flexibly changed by bending the flexible part 20.

[0059] As a measure for efficiently cooling the main body part in a welding torch having such a flexible part, it is conceivable to arrange the cooling pipe of the cooling part so as to reach the main body part. However, in this case, the cooling pipe will cross the flexible part where bending is repeatedly performed. Therefore, the risk of the cooling pipe being damaged or the like increases, and as a result, it becomes difficult to ensure the durability of the welding torch.

[0060] In this regard, in the welding torch 1 according to the present embodiment, as described above, the flexible heat pipe 23 having excellent thermal conductivity and flexibility is provided in the flexible portion 20. As a result, it is not necessary to arrange the cooling pipe 31 so as to cross the flexible portion 20, and thus it is possible to ensure the durability of the welding torch 1.

[0061] Therefore, by adopting the welding torch 1 according to the present embodiment, in a welding torch configured to be able to change the direction of the tip, it is possible to improve the cooling performance while ensuring durability.

[0062] In addition, in the welding torch 1 according to the present embodiment described above, the case where the flexible heat pipe 23 includes the winding portion 23a has been described as an example. However, the flexible heat pipe 23 does not necessarily include the winding portion 23a. Further, instead of the winding portion 23a, the flexible heat pipe 23 may include a meandering portion arranged to meander along the outer periphery of the coil element 21. Also in this case, since this meandering portion serves as a play when the flexible heat pipe 23 deforms following the flexible portion 20, the load on the flexible heat pipe 23 during the deformation can be reduced.

[0063] Also, in the welding torch 1 according to the present embodiment described above, the case where one flexible heat pipe 23 is provided in the flexible portion 20 has been described as an example. However, a plurality of flexible heat pipes 23 may be provided in the flexible portion 20.

[0064] Furthermore, in the welding torch 1 according to the present embodiment described above, the case where the flexible heat pipe 23 is arranged along the outer periphery of the coil element 21 has been described as an example. However, the flexible heat pipe 23 may be arranged along the inner periphery of the coil element 21.

[0065] In addition, in the welding torch 1 according to the above-described embodiment, the case where the cylindrical portion that supports the electrode rod 11 is constituted by the collet 12, the collet body 13, and the conductive portion 14 has been described as an example. However, the cylindrical portion is not necessarily limited to being constituted by these, and may further include other members in addition to these, or a part or all of these may be integrally formed.

[0066] (Other forms, etc.) In the embodiments described above, the shape, configuration, size, number, material, etc. of each part shown can be variously changed as long as they do not depart from the gist of the present invention.

[0067] In addition, the characteristic configurations shown in the above-described embodiments of the present invention can be naturally combined with each other within a range not departing from the gist of the present invention.

[0068] Thus, the above-described embodiments disclosed this time are illustrative in all respects and not restrictive. The technical scope of the present invention is defined by the scope of the claims, and includes all modifications within the meaning and scope equivalent to the description of the scope of the claims.

Explanation of reference numerals

[0069] 1 Welding torch, 10 Main body portion, 11 Electrode rod, 12 Collet, 13 Collet body, 14 Conductive portion, 20 Flexible portion, 21 Coil element, 22 Second cover portion, 23 Flexible heat pipe, 23a Wrapping portion, 30 Cooling portion.

Claims

1. An electrode rod, a main body portion having a cylindrical portion for supporting the electrode rod, A cooling portion provided with a flow path for a cooling fluid inside, A flexible flexible portion that connects the main body portion and the cooling portion to each other, A welding torch comprising a flexible heat pipe provided in the flexible portion and having flexibility and contacting each of the cylindrical portion and the cooling portion.

2. The welding torch according to claim 1, wherein the flexible heat pipe includes a winding portion wound around the flexible portion.

3. The cylindrical portion includes a collet that supports the electrode rod, a collet body that contacts the outer periphery of the collet, and a conductive portion that contacts the outer periphery of the collet body, The welding torch according to claim 1 or 2, wherein the flexible heat pipe contacts the conductive portion of the cylindrical portion.

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