JP2025016114A - Welding torch - Google Patents

Abstract

A welding torch suitable for miniaturization is provided.
[Solution] The welding torch A1 comprises a non-consumable electrode 25 extending in an axial direction z, an inner nozzle 30 and an outer nozzle 31 arranged radially outward from the non-consumable electrode 25 at the end of the non-consumable electrode 25 on one axial side z1, a torch body 2 arranged on the other axial side z2 from the inner nozzle 30 and the outer nozzle 31 and including a connecting member 21 made of a conductive material, and a first gas pipe 41 and a second gas pipe 42 each connected to the connecting member 21, and each of the first gas pipe 41 and the second gas pipe 42 is made of a conductive material.
[Selected figure] Figure 3

Description

This disclosure relates to a welding torch.

In welding (TIG welding or plasma welding) using a welding torch equipped with a non-consumable electrode, an arc is generated between an electrode (non-consumable electrode) made of tungsten and the workpiece, and the heat of the arc melts the workpiece. In TIG welding, a shielding gas is flowed between the gas nozzle and the electrode. In plasma welding, in addition to the shielding gas, plasma gas is flowed inside a plasma tip arranged around the electrode, thereby constraining the arc (plasma arc). As a result, a highly concentrated high-temperature plasma flow is generated, and the stored energy is used to perform welding. Patent Document 1 discloses a welding torch that can be used to perform welding work by selectively using TIG welding and plasma welding.

The welding torch described in Patent Document 1 includes an inner nozzle and an outer nozzle. The inner nozzle is detachable, and can be used for, for example, plasma welding with the inner nozzle attached and TIG welding with the inner nozzle detached. In the welding torch described in Patent Document 1, the torch body is provided with two gas inlets (a first gas inlet and a second gas inlet). Different gases are supplied to each of these gas inlets from gas piping such as rubber hoses. The torch body also has a block member made of a conductive material, and the block member receives power from a power source via a power supply cable or the like (see Figures 1 and 5 of Patent Document 1). However, in manual welding, in which an operator holds a welding torch to perform welding work, there is a strong demand for a smaller welding torch, and there was room for improvement in the welding torch described in Patent Document 1.

JP 2023-42306 A

This disclosure was conceived under these circumstances, and its main objective is to provide a welding torch that is suitable for miniaturization.

To solve the above problems, this disclosure employs the following technical solutions:

The welding torch provided by the present disclosure comprises a non-consumable electrode extending in an axial direction, a nozzle disposed radially outward from the non-consumable electrode at one end of the non-consumable electrode in the axial direction, a torch body disposed on the other side of the nozzle in the axial direction and including a connecting member made of a conductive material, and a first gas pipe and a second gas pipe each connected to the connecting member, each of the first gas pipe and the second gas pipe being made of a conductive material.

In a preferred embodiment, the cross-sectional area of the second gas pipe is larger than the cross-sectional area of the first gas pipe.

In a preferred embodiment, the second gas pipe has a small diameter pipe section having one end connected to the connecting member, and a large diameter pipe section having one end connected to the other end of the small diameter pipe section and having an outer diameter larger than that of the small diameter pipe section.

In a preferred embodiment, the device further includes a conductive member that is electrically connected to both the first gas pipe and the second gas pipe.

In a preferred embodiment, the torch body includes a first cylindrical portion extending along the axial direction and a second cylindrical portion connected to the first cylindrical portion and extending in a direction intersecting the axial direction, the first cylindrical portion and the second cylindrical portion are made of an insulating material, the connecting member is disposed radially inside the first cylindrical portion, and the first gas pipe and the second gas pipe pass through the inside of the second cylindrical portion.

In the preferred embodiment, no cooling mechanism is provided.

According to the welding torch of the present disclosure, each of the first gas pipe and the second gas pipe can serve as both a gas flow path and a current path. This allows the size of the torch body to be reduced, and the welding torch to be made more compact.

Other features and advantages of the present disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings.

FIG. 1 is a front view showing a welding torch according to a first embodiment of the present disclosure. FIG. 2 is a plan view of the welding torch shown in FIG. 1 . 3 is a cross-sectional view taken along line III-III in FIG. 2. FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 4 is an enlarged cross-sectional view taken along line VV in FIG. 3. FIG. 6 is an enlarged cross-sectional view taken along line VI-VI in FIG. FIG. 4 is a partially enlarged view of FIG. 3 . FIG. 4 is a cross-sectional view showing a welding torch according to a second embodiment of the present disclosure. 9 is a cross-sectional view taken along line IX-IX in FIG. 8.

Below, preferred embodiments of the present disclosure will be described in detail with reference to the drawings. In the following description, terms such as "first" and "second" are used merely as labels and are not necessarily intended to assign a rank to their objects.

1 to 7 show a welding torch according to the first embodiment of the present disclosure. The welding torch A1 of this embodiment includes a handle 1, a torch body 2, insulating rings 23 and 24, a non-consumable electrode 25, a collet body 26, a collet 27, a collet pressing member 28, a cap 29, an inner nozzle 30, an outer nozzle 31, a nozzle holder 32, a locking member 33, an electrode centering member 34, a first gas pipe 41, a second gas pipe 42, and a conductive member 43. The welding torch A1 of this embodiment is configured to be held by an operator in his/her hand to perform welding work. In addition, as will be described in detail later, the welding torch A1 has two gas flow paths (a first gas flow path G1 and a second gas flow path G2) for flowing a predetermined welding gas. In addition, the welding torch A1 does not include a cooling mechanism.

In the description of welding torch A1, the up-down direction in Figures 1 and 3 is an example of the "axial direction" of this disclosure, and is referred to as the "axial direction z." In Figures 3 and 7, the direction perpendicular to the axial direction z (the left-right direction in the figures) is referred to as the "first direction x." In addition, the lower side in Figures 1 and 3 is an example of the "one side of the axial direction" of this disclosure, and is referred to as the "one axial side z1," and the upper side in the figures is an example of the "other axial side" of this disclosure, and is referred to as the "other axial side z2."

The handle 1 is the part that the operator holds with his/her hand. As shown in FIG. 3, the handle 1 is a cylindrical member made of an insulating material.

The torch body 2 is cylindrical, and one end is held by the handle 1. The torch body 2 includes a main body 20 and a connecting member 21. The main body 20 appropriately houses the components of the welding torch A1 inside. The main body 20 is made of an insulating material. The main body 20 has a first cylindrical portion 20A and a second cylindrical portion 20B.

The first cylindrical portion 20A extends along the axial direction z. The second cylindrical portion 20B is connected to the first cylindrical portion 20A in a branched manner. The second cylindrical portion 20B extends in a direction intersecting the axial direction z (the upper right direction in FIG. 3). In the illustrated example, the angle between the direction in which the first cylindrical portion 20A extends (axial direction z) and the direction in which the second cylindrical portion 20B extends is about 70°. The angle between the direction in which the first cylindrical portion 20A extends (axial direction z) and the direction in which the second cylindrical portion 20B extends is not particularly limited, and may be a right angle (90°), for example. The end of the second cylindrical portion 20B (the end on the upper right side in FIG. 3) is held by the end of the handle 1. In the illustrated example, the end of the second cylindrical portion 20B and the end of the handle 1 are fixed to each other by a screw connection.

The connection member 21 is disposed radially inside the first cylindrical portion 20A. The connection member 21 is a member that receives power from a power supply unit (not shown) and is made of a conductive material. An example of the conductive material that constitutes the connection member 21 is copper. The connection member 21 has a cylindrical shape as a whole. As shown in FIG. 7, the connection member 21 has a first gas inlet 211, a second gas inlet 212, a tapered surface 214, and a female thread portion 215.

The insulating rings 23 and 24 are each a cylindrical member made of an insulating material. The insulating ring 23 is disposed adjacent to the other axial side z2 of the first cylindrical portion 20A. The insulating ring 24 is disposed adjacent to one axial side z1 of the second cylindrical portion 20B.

The non-consumable electrode 25 is a rod-shaped conductor extending along the axial direction z (the direction in which the axis CL extends). The non-consumable electrode 25 is made of, for example, tungsten. The non-consumable electrode 25 is electrically connected to the power supply via the connection member 21, and generates an arc between the non-consumable electrode 25 and the workpieces when an arc voltage is applied between the non-consumable electrode 25 and the workpieces.

The non-consumable electrode 25 is cylindrical with a constant outer diameter. The non-consumable electrode 25 is designed to have a constant outer diameter, and may include some manufacturing error. The outer diameter of the non-consumable electrode 25 is not particularly limited, and in this embodiment, it is, for example, about 1.0 to 4.0 mm.

The collet body 26, collet 27, and collet pressing member 28 cooperate with each other to hold the non-consumable electrode 25. The collet body 26, collet 27, and collet pressing member 28 are made of a conductive material. An example of the conductive material that constitutes the collet body 26, collet 27, and collet pressing member 28 is copper.

The collet 27 surrounds the non-consumable electrode 25. The collet body 26 is disposed radially outward of the collet 27. The collet body 26 is disposed radially inward of the connecting member 21. Although detailed illustrations are omitted, the collet body 26 is fixed to the connecting member 21, for example, by a screw connection.

The collet pressing member 28 is disposed on the other axial side z2 relative to the collet 27. Although detailed illustrations are omitted, the collet pressing member 28 has a screw portion that is screwed into the connection member 21. As shown in FIG. 7, a female screw portion 215 is formed at the upper end (the end on the other axial side z2) of the connection member 21, and the above-mentioned screw portion of the collet pressing member 28 is screwed into the female screw portion 215. A cap 29 is provided on the other axial side z2 of the collet pressing member 28. By turning this cap 29, the position of the collet pressing member 28 in the axial direction z relative to the collet body 26 can be adjusted. The end of the collet pressing member 28 on the one axial side z1 abuts against the end of the collet 27 on the other axial side z2. When the collet pressing member 28 is moved to the one axial side z1, the collet 27 is pressed against the one axial side z1.

The collet 27 has multiple slits formed at its tip (one axial side z1) that extend in the axial direction z, and has multiple movable pieces 271 located between adjacent slits. As described above, when the collet pressing member 28 is moved toward one axial side z1, the collet 27 is pressed toward one axial side z1. Then, the multiple movable pieces 271 at the tip of the collet 27 are pressed against the tip of the collet body 26, reducing its diameter, and the collet 27 holds the non-consumable electrode 25 by sandwiching it. In this way, the collet body 26, collet 27, and collet pressing member 28 cooperate with each other to hold the non-consumable electrode 25.

As shown in FIG. 3, the inner nozzle 30 is disposed around the tip of the non-consumable electrode 25 (the end on one axial side z1). The inner nozzle 30 is disposed on one axial side z1 relative to the collet body 26. The inner nozzle 30 is substantially cylindrical and disposed radially outward of the non-consumable electrode 25. In this embodiment, an electrode centering member 34 is interposed between the inner nozzle 30 and the non-consumable electrode 25.

The locking member 33 is fitted over both the collet body 26 and the inner nozzle 30. More specifically, the locking member 33 is fitted over the end of the collet body 26 on one axial side z1 and the end of the inner nozzle 30 on the other axial side z2. In the illustrated example, the locking member 33 has a cap nut structure.

In this embodiment, as shown in FIG. 3, the locking member 33 and the end of the collet body 26 on one axial side z1 are screwed together. For example, a male thread 261 is formed on the outer periphery of the end of the collet body 26 on one axial side z1, and a female thread 331 formed on the locking member 33 is screwed into the male thread 261 of the collet body 26. Meanwhile, the portion of the locking member 33 on one axial side z1 is fitted onto the inner nozzle 30, and the locking member 33 is locked by a large diameter portion of the outer periphery on the other axial side z2 of the inner nozzle 30. This limits the relative movement of the inner nozzle 30 and the locking member 33 in the axial direction z.

The electrode centering member 34 is roughly cylindrical and is disposed radially outside the non-consumable electrode 25 and radially inside the inner nozzle 30. A tapered recess is formed on the inner circumference of the inner nozzle 30 on the other axial side z2, and the tapered protrusion of the electrode centering member 34 fits into this tapered recess. The inner diameter dimension of the electrode centering member 34 is slightly larger than the outer diameter dimension of the non-consumable electrode 25 (electrode main portion 251). As a result, the electrode centering member 34 is concentrically fitted around the non-consumable electrode 25. In addition, the tapered protrusion of the electrode centering member 34 fits into the tapered recess of the inner nozzle 30. As a result, the inner nozzle 30 is concentrically fitted around the electrode centering member 34. Therefore, the inner nozzle 30 is disposed concentrically around the non-consumable electrode 25 via the electrode centering member 34. As shown in FIG. 6, a plurality of grooves 341 are formed on the outer periphery of the electrode centering member 34. These grooves 341 are provided at regular intervals around the circumference of the electrode core member 34. A gap is formed between the portion where the grooves 341 are formed and the inner nozzle 30, and this gap constitutes the first gas flow path G1, which will be described later.

In this embodiment, the tip of the non-consumable electrode 25 coincides with the tip of the inner nozzle 30 in the axial direction z, or protrudes slightly from the tip of the inner nozzle 30 to one axial side z1. The protruding length by which the tip of the non-consumable electrode 25 protrudes from the tip of the inner nozzle 30 to one axial side z1 is, for example, in the range of 0 to 5 mm.

The nozzle holder 32 is cylindrical. The nozzle holder 32 is integrally connected to the outer periphery of the middle part of the collet body 26 in the axial direction z by means of, for example, brazing.

As shown in FIG. 3, the outer nozzle 31 is disposed radially outward of the inner nozzle 30. The outer nozzle 31 is disposed on one axial side z1 of the first cylindrical portion 20A, and an insulating ring 24 is interposed between the outer nozzle 31 and the first cylindrical portion 20A. In the illustrated example, the outer nozzle 31 is generally cylindrical, and the tip side (one axial side z1) has a smaller diameter than other portions. In this embodiment, the outer nozzle 31 is disposed concentrically with the non-consumable electrode 25 and the inner nozzle 30. The outer nozzle 31 is attached, for example, by a screw connection to the outer periphery of the nozzle holder 32.

As shown in FIG. 3, in this embodiment, the tip of the inner nozzle 30 protrudes from the tip of the outer nozzle 31 to one axial side z1. The protruding length by which the tip of the inner nozzle 30 protrudes from the tip of the outer nozzle 31 to one axial side z1 is, for example, in the range of 0 to 5 mm.

As shown in Figures 3 to 7, in this embodiment, the welding torch A1 is formed with a first gas flow path G1 and a second gas flow path G2.

In this embodiment, the welding gas supplied to the welding torch A1 includes two types of inert gas that differ in gas supply manner, such as gas type and flow rate. For convenience of explanation, the two types of inert gas are appropriately distinguished as a "first inert gas" and a "second inert gas."

The first gas flow path G1 is a flow path for flowing the first inert gas. In FIG. 3, the flow of the first inert gas is indicated by the two-dot chain arrows. The first gas flow paths G1 are formed between the collet 27 and the collet body 26, between the non-consumable electrode 25 and the collet 27, between the non-consumable electrode 25 and the collet body 26, between the electrode centering member 34 and the inner nozzle 30, and between the non-consumable electrode 25 and the inner nozzle 30.

In this embodiment, as shown in Figures 3 and 7, the torch body 2 (connecting member 21) is provided with a first gas inlet 211 for introducing a first inert gas. The first gas inlet 211 is connected to the first gas flow path G1. When the first inert gas is introduced from the first gas inlet 211, the first inert gas flows in the first gas flow path G1 from the other axial side z2 to the one axial side z1, passes between the non-consumable electrode 25 and the inner nozzle 30, and then is ejected from the opening at the tip of the inner nozzle 30.

The second gas flow path G2 is a flow path for flowing the second inert gas. In FIG. 3, the flow of the second inert gas is indicated by dotted arrows. The second gas flow paths G2 are formed between the collet body 26 and the connecting member 21, between the collet body 26 and the insulating ring 24, between the nozzle holder 32, the locking member 33 and the outer nozzle 31, and between the inner nozzle 30 and the outer nozzle 31.

In this embodiment, as shown in Figures 3 and 7, the torch body 2 (connecting member 21) is provided with a second gas inlet 212 for introducing a second inert gas. The second gas inlet 212 is connected to the second gas flow passage G2. When the second inert gas is introduced from the second gas inlet 212, the second inert gas flows in the second gas flow passage G2 from the other axial side z2 to the one axial side z1, passes between the inner nozzle 30 and the outer nozzle 31, and is then ejected from the opening at the tip of the outer nozzle 31.

The first gas inlet 211, the second gas inlet 212, the tapered surface 214, and the female threaded portion 215 of the connection member 21 will be described with reference to FIG. 7 and other figures. As shown in FIG. 7, the first gas inlet 211 is located on the other axial side z2 relative to the second gas inlet 212. The first gas inlet 211 extends along the first direction x.

The second gas inlet 212 is inclined with respect to the first direction x. The second gas inlet 212 is inclined so as to be located on one axial side z1 as it approaches the non-consumable electrode 25 in the first direction x. The first cylindrical portion 20A, which is located radially outside the connecting member 21, is positioned across the first gas inlet 211 and the second gas inlet 212 in the axial direction z.

The opening end of the second gas inlet 212 is located on the tapered surface 214. The tapered surface 214 is inclined so as to be located on the other axial side z2 as it approaches the non-consumable electrode 25. In the cross section shown in FIG. 7, the angle between the tapered surface 214 and the second gas inlet 212 is approximately a right angle.

As shown in FIG. 7, the female threaded portion 215 is adjacent to the first gas inlet 211 on the other axial side z2. As described above, the threaded portion of the collet retainer member 28 is screwed into this female threaded portion 215.

3 and 7, the first gas pipe 41 and the second gas pipe 42 are inserted into the inside of the second cylindrical portion 20B. The first gas pipe 41 is a pipe for flowing the first inert gas, and is connected to the first gas inlet 211 of the connection member 21. The first gas pipe 41 is made of a conductive material. The conductive material for the first gas pipe 41 is not particularly limited, and may be, for example, copper. The thickness of the first gas pipe 41 is not particularly limited, and in the illustrated example, the outer diameter dimension of the first gas pipe 41 is about 4 mm, the inner diameter dimension is about 2 mm, and the thickness of the first gas pipe 41 is about 1 mm. The first gas pipe 41 is appropriately bent. The end of the first gas pipe 41 that is connected to the first gas inlet 211 extends along the first direction x. One end of the first gas pipe 41 (the end that is connected to the first gas inlet 211) is connected to the connection member 21 by means such as brazing. As a result, the first gas pipe 41 is electrically connected to the connection member 21.

The second gas pipe 42 is a pipe through which the second inert gas flows, and is connected to the second gas inlet 212 of the connection member 21. In this embodiment, the second gas pipe 42 is thicker than the first gas pipe 41, and the cross-sectional area of the second gas pipe 42 is larger than the cross-sectional area of the first gas pipe 41. In this embodiment, the second gas pipe 42 includes a small diameter pipe section 421 and a large diameter pipe section 422. The small diameter pipe section 421 is connected to the second gas inlet 212 of the connection member 21. One end of the small diameter pipe section 421 (the end that is connected to the second gas inlet 212) is connected to the connection member 21 by means such as brazing. As a result, the small diameter pipe section 421 is electrically connected to the connection member 21. The large diameter pipe section 422 is thicker than the small diameter pipe section 421, and the cross-sectional area of the large diameter pipe section 422 is larger than the cross-sectional area of the small diameter pipe section 421. One end of the large diameter pipe section 422 is connected to the other end of the small diameter pipe section 421 (the end opposite the connecting member 21) by means of brazing or the like. As a result, the large diameter pipe section 422 is electrically connected to the small diameter pipe section 421. The thickness of the second gas pipe 42 (the small diameter pipe section 421 and the large diameter pipe section 422) is not particularly limited. In the illustrated example, the small diameter pipe section 421 has an outer diameter of about 6 mm, an inner diameter of about 2 mm, and a thickness of about 2 mm. The large diameter pipe section 422 has an outer diameter of about 8 mm, an inner diameter of about 4 mm, and a thickness of about 2 mm.

As shown in FIG. 3, the conductive member 43 is attached to the first gas pipe 41 and the second gas pipe 42. In this embodiment, the conductive member 43 is attached to the other end of the first gas pipe 41 (the end opposite the connection member 21) and the middle part of the large diameter pipe section 422. The conductive member 43 is fixed to the first gas pipe 41 and the large diameter pipe section 422 by means of, for example, brazing. As a result, the conductive member 43 is electrically conductive to both the first gas pipe 41 and the large diameter pipe section 422 (second gas pipe 42).

A power supply cable (not shown) is connected via a connector to the other end (the end opposite the connection member 21) of the large diameter tube section 422 (second gas pipe 42). The second gas pipe 42 is electrically connected to the power supply unit via the power supply cable. The second gas pipe 42 and the first gas pipe 41, which is electrically connected to the second gas pipe 42 via the conductive member 43, form a current path through which current flows during welding.

The conductor cross-sectional areas of the first gas pipe 41 and the second gas pipe 42 are as follows. The conductor cross-sectional area of the first gas pipe 41 is about 9.4 ^mm2 . In the second gas pipe 42, the conductor cross-sectional area of the small diameter pipe section 421 is about 25.1 ^mm2 , and the conductor cross-sectional area of the large diameter pipe section 422 is about 37.7 ^mm2 . The first gas pipe 41 and the second gas pipe 42 form a bifurcated current path by the conductive member 43. Therefore, the conductor cross-sectional area of the current path during welding is the sum of the conductor cross-sectional area of the first gas pipe 41 and the conductor cross-sectional area of the second gas pipe 42, and is about 34.6 ^mm2 for the small diameter pipe section 421 and about 47.1 ^mm2 for the large diameter pipe section 422. As a result, the conductor cross-sectional area of the current path (first gas pipe 41 and second gas pipe 42) during welding is larger than the conductor cross-sectional area (30 mm ² ) required for a power cable carrying a current of 200 A, ensuring a sufficient conductor cross-sectional area.

The type of each of the first inert gas and the second inert gas supplied to the welding torch A1 is not particularly limited, and may be, for example, a gas containing at least one selected from argon (Ar) gas and helium (He) gas. The flow rates of the first inert gas and the second inert gas supplied to the welding torch A1 are individually adjusted as appropriate depending on the welding conditions, etc.

Next, the operation of this embodiment will be explained.

The welding torch A1 of this embodiment includes a non-consumable electrode 25 extending in the axial direction z, an inner nozzle 30, an outer nozzle 31, a torch body 2, and a first gas pipe 41 and a second gas pipe 42. The inner nozzle 30 and the outer nozzle 31 are arranged radially outward from the non-consumable electrode 25 at the end of one axial side z1 of the non-consumable electrode 25. A first gas flow path G1 is formed between the non-consumable electrode 25 and the inner nozzle 30. The outer nozzle 31 is arranged radially outward from the inner nozzle 30, and a second gas flow path G2 is formed between the inner nozzle 30 and the outer nozzle 31. According to this configuration, during welding operation, the first inert gas flowing through the first gas flow path G1 and ejected from the tip of the inner nozzle 30 functions as a plasma gas, and the second inert gas flowing through the second gas flow path G2 and ejected from the tip of the outer nozzle 31 functions as a shielding gas. This narrows the arc that is generated between the workpiece and the tip of the non-consumable electrode 25, allowing efficient welding using an arc with high energy density (plasma arc).

The torch body 2 is disposed on the other axial side z2 relative to the inner nozzle 30 and the outer nozzle 31, and includes a connecting member 21. The connecting member 21 is made of a conductive material, and the first gas pipe 41 and the second gas pipe 42 are each connected to the connecting member 21. The first gas pipe 41 and the second gas pipe 42 are each made of a conductive material. With this configuration, the first gas pipe 41 and the second gas pipe 42 can each serve as both a gas flow path for flowing the first inert gas and the second inert gas, and a current path during welding. This allows the size of the torch body 2 (the first cylindrical portion 20A, the second cylindrical portion 20B, and the connecting member 21) to be reduced, and the welding torch A1 can be made smaller. The welding torch A1 of this embodiment is a hand-held type that is held by the operator in the hand to perform welding work. The reduction in size of the welding torch A1 contributes to reducing the burden on the operator, and is expected to improve welding work.

As described above, the welding torch A1 of this embodiment does not have a cooling mechanism. For this reason, no cooling water piping for sending cooling water is arranged in the second cylindrical portion 20B of the torch body 2 (main body 20), and no cooling water flow path for flowing cooling water is provided in the torch body 2 (connecting member 21). This is preferable in terms of miniaturizing the welding torch A1.

Because the welding torch A1 does not have a cooling mechanism, the current path through which current flows during welding is prone to temperature rise due to resistance heating. In this embodiment, the two first gas pipes 41 and the second gas pipes 42 both function as current paths during welding. This is suitable for increasing the conductor cross-sectional area of the current paths. This makes it possible to suppress resistance heating in the first gas pipe 41 and the second gas pipe 42 during welding.

The cross-sectional area of the second gas pipe 42 is larger than the cross-sectional area of the first gas pipe 41. With this configuration, it is possible to increase the conductor cross-sectional area of the first gas pipe 41 and the second gas pipe 42, which are the current paths during welding, while miniaturizing the welding torch A1 (the second cylindrical portion 20B of the torch body 2).

The second gas pipe 42 includes a small diameter pipe section 421 and a large diameter pipe section 422 having an outer diameter larger than that of the small diameter pipe section 421. One end of the small diameter pipe section 421 (the end leading to the second gas inlet 212) is connected to the connecting member 21, and one end of the large diameter pipe section 422 is connected to the other end of the small diameter pipe section 421 (the end opposite the connecting member 21). With this configuration, the conductor cross-sectional area of the current path (first gas pipe 41 and second gas pipe 42) during welding can be secured to be large, and the size of the torch body 2 (second cylindrical section 20B and connecting member 21) can be reduced.

The welding torch A1 includes a conductive member 43. The conductive member 43 is attached to the first gas pipe 41 and the second gas pipe 42, and is electrically connected to both the first gas pipe 41 and the second gas pipe 42. With this configuration, a bifurcated current path can be appropriately formed by the first gas pipe 41 and the second gas pipe 42.

The main body 20 (torch body 2) includes a first cylindrical portion 20A and a second cylindrical portion 20B connected to the first cylindrical portion 20A. The first cylindrical portion 20A extends along the axial direction z, and the second cylindrical portion 20B extends in a direction intersecting the axial direction z. The main body 20 (the first cylindrical portion 20A and the second cylindrical portion 20B) is made of an insulating material. The connecting member 21 is disposed radially inside the first cylindrical portion 20A. The first gas pipe 41 and the second gas pipe 42 pass through the inside of the second cylindrical portion 20B. With this configuration, the connecting member 21, the first gas pipe 41, and the second gas pipe 42 can be efficiently disposed inside the insulating first cylindrical portion 20A and the second cylindrical portion 20B. This is more preferable in terms of miniaturizing the welding torch A1.

Figures 8 and 9 show a welding torch according to a second embodiment of the present disclosure. Figure 8 is a cross-sectional view showing a welding torch A2 of this embodiment, and shows a cross section similar to that of Figure 3. Figure 9 is a cross-sectional view taken along line IX-IX of Figure 8. Note that in Figures 8 and 9, elements that are the same as or similar to those in the above embodiment are given the same reference numerals as those in the above embodiment, and descriptions thereof will be omitted as appropriate.

The welding torch A2 of this embodiment differs from the above embodiment in the configuration of the second gas pipe 42 and further includes two conductive rods 44, 45. The thickness of the second gas pipe 42 is thinner than that of the above embodiment and has a constant thickness overall. In this embodiment, the outer diameter and inner diameter dimensions of the second gas pipe 42 are the same as those of the first gas pipe 41.

The conductive rods 44, 45 are inserted into the second tubular portion 20B. Each conductive rod 44, 45 is made of a conductive material and is a solid metal rod. The conductive material that makes up the conductive rods 44, 45 is not particularly limited, and may be copper, for example. The thickness of the conductive rods 44, 45 is not particularly limited, and in the illustrated example, the outer diameter of each conductive rod 44, 45 is about 3 mm. One end of each conductive rod 44, 45 (the end on the connection member 21 side) is connected to the connection member 21 by means of brazing or the like. As a result, the conductive rods 44, 45 are electrically connected to the connection member 21.

In this embodiment, the conductive member 43 is also attached to the conductive rods 44 and 45. The conductive member 43 is attached to the other end of each of the conductive rods 44 and 45 (the end opposite the connection member 21). The conductive member 43 is fixed to the conductive rods 44 and 45 by means of, for example, brazing. As a result, the conductive member 43 is electrically connected to all of the first gas pipe 41, the second gas pipe 42, and the conductive rods 44 and 45.

A power supply cable (not shown) is connected via a connector to the other end of the second gas pipe 42 (the end opposite the connection member 21). The second gas pipe 42 is electrically connected to the power supply unit via the power supply cable. The second gas pipe 42, as well as the first gas pipe 41 and the conductive rods 44 and 45 which are electrically connected to the second gas pipe 42 via the conductive member 43, form a current path through which current flows during welding.

The conductor cross-sectional areas of the first gas pipe 41, the second gas pipe 42, and the conductive rods 44, 45 are as follows. The conductor cross-sectional area of the first gas pipe 41 and the second gas pipe 42 is about 9.4 ^mm2 . The conductor cross-sectional area of the conductive rods 44, 45 is about 7.1 ^mm2 . The first gas pipe 41, the second gas pipe 42, and the conductive rods 44, 45 are electrically connected by the conductive member 43, and form a current path. Therefore, the conductor cross-sectional area of the current path during welding is the sum of the conductor cross-sectional areas of the first gas pipe 41, the second gas pipe 42, and the conductive rods 44, 45, which is about 33.0 ^mm2 . As a result, the conductor cross-sectional area of the current path during welding (first gas piping 41, second gas piping 42 and conductive rods 44, 45) is larger than the conductor cross-sectional area (30 ^mm2 ) required for a power cable carrying a current of 200 A, ensuring sufficient conductor cross-sectional area.

In the welding torch A2, the torch body 2 is disposed on the other axial side z2 relative to the inner nozzle 30 and the outer nozzle 31, and includes a connecting member 21. The connecting member 21 is made of a conductive material, and the first gas pipe 41 and the second gas pipe 42 are each connected to the connecting member 21. Each of the first gas pipe 41 and the second gas pipe 42 is made of a conductive material. With this configuration, each of the first gas pipe 41 and the second gas pipe 42 can play the role of both a gas flow path for flowing the first inert gas and the second inert gas, and a current path during welding. This allows the size of the torch body 2 (the first cylindrical portion 20A, the second cylindrical portion 20B, and the connecting member 21) to be reduced, and the welding torch A1 can be made smaller. The welding torch A2 of this embodiment is a hand-held type that is held by the operator in the hand to perform welding work. The miniaturization of the welding torch A1 contributes to reducing the burden on the operator, and is expected to improve welding work.

The welding torch A2 of this embodiment does not have a cooling mechanism. Therefore, the current path through which current flows during welding is prone to temperature rise due to resistance heating. In this embodiment, the two first gas pipes 41, the second gas pipe 42, and the two conductive rods 44, 45 all function as current paths during welding. This is suitable for increasing the conductor cross-sectional area of the current paths. This makes it possible to suppress resistance heating in the current paths (the first gas pipe 41, the second gas pipe 42, and the conductive rods 44, 45) during welding.

The welding torch according to the present disclosure is not limited to the above-described embodiment. The specific configuration of each part of the welding torch according to the present disclosure can be freely designed in various ways.

A1, A2: welding torch, 2: torch body, 20A: first cylindrical portion, 20B: second cylindrical portion, 21: connecting member, 25: non-consumable electrode, 30: inner nozzle (nozzle), 31: outer nozzle (nozzle), 41: first gas pipe, 42: second gas pipe, 421: small diameter tube portion, 422: large diameter tube portion, 43: conductive member, z: axial direction, z1: one side of axial direction, z2: other side of axial direction

Claims (5)

a non-consumable electrode extending in an axial direction;
a nozzle disposed radially outwardly of the non-consumable electrode at one end of the non-consumable electrode in the axial direction;
a torch body including a connecting member made of a conductive material, the connecting member being disposed on the other side of the nozzle in the axial direction;
a first gas pipe and a second gas pipe each connected to the connection member;
A welding torch, wherein each of the first gas pipe and the second gas pipe is made of a conductive material. The welding torch of claim 1, wherein the cross-sectional area of the second gas pipe is greater than the cross-sectional area of the first gas pipe. The second gas pipe has a small diameter pipe portion connected to the connecting member at one end thereof.
3. The welding torch according to claim 2, further comprising: a large diameter tubular portion having an outer diameter larger than that of the small diameter tubular portion, the large diameter tubular portion having one end connected to the other end of the small diameter tubular portion. The welding torch according to any one of claims 1 to 3, further comprising a conductive member electrically connected to both the first gas pipe and the second gas pipe. The torch body includes a first cylindrical portion extending along the axial direction, and a second cylindrical portion connected to the first cylindrical portion and extending in a direction intersecting the axial direction,
the first cylindrical portion and the second cylindrical portion are made of an insulating material,
The connection member is disposed radially inside the first cylindrical portion,
The welding torch according to claim 1 , wherein the first gas pipe and the second gas pipe extend through the second cylindrical portion.

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