JP2022039313A - Welding torch - Google Patents

Abstract

To provide a welding torch which is suitable for achieving reduction of inclination of a shield gas passage in an internal space of a torch body and a chip body and improving gas shield performance during welding in a structure in which a coil liner is disposed in the internal spaces and a shield gas flows in the internal spaces.SOLUTION: A welding torch A1 includes: a cylindrical torch body 2; a cylindrical chip body 3 attached to a tip of the torch body 2; and a coil liner 8 which is formed by winding a metal wire into a spiral shape, disposed in internal spaces S of the torch body 2 and the chip body 3, and used to pass a welding wire. The internal spaces S are passages in which a shield gas flows. The coil liner 8 has a large diameter part 81 (a protruding part) which protrudes so that the chip body 3 and the coil liner 8 are located closer to each other than in other portions or contact with each other.SELECTED DRAWING: Figure 2

Description

The present invention relates to a welding torch.

For example, a welding torch used in consumable electrode arc welding is configured so that a welding wire is sent out while receiving power supplied from a feeding tip. The weld wire is passed through a wire insertion hole of the power feeding tip and receives power by contacting the inner surface of the wire insertion hole. The welding torch is described in, for example, Patent Document 1.

As shown in Patent Document 1, the welding torch includes a torch body, a tip body, a feeding tip, and a nozzle. All of these are cylindrical, and the tip body is attached to the tip of the torch body. The feeding chip is attached to the tip of the chip body. The nozzle is a tubular member that forms an annular space that opens forward on the outside of the chip body or the feeding chip.

The welding wire passing through the inside of the welding torch is sent out while being guided by a guide member such as a coil liner. The coil liner is formed by winding a metal wire in a spiral shape. The coil liner is inserted from the base end side of the torch body, for example, and is arranged in the internal space of the torch body or the chip body. The coil liner extends close to the feeding tip, and a welding wire is inserted inside the coil liner.

The welding torch is also configured so that a shield gas composed of an inert gas or the like is ejected from a nozzle at the tip. When the shield gas is sent to the welding torch, the shield gas passes through the internal space of the torch body and the chip body, and is sent to the inner space of the nozzle through, for example, an orifice member attached to the tip of the chip body, and the nozzle. It is ejected from the tip of. The internal space of the torch body and the chip body serves as a flow path through which the shield gas flows. Further, when the coil liner is arranged in the internal space of the torch body and the chip body, an appropriate gap is provided between the coil liner and the inner peripheral surface of the torch body or the chip body, and the shield gas is mainly used. It flows through the gap.

However, the coil liner is inserted into the internal space of the torch body and the chip body, and the torch body and the chip body may be unevenly arranged such as along the inner surface. Then, the flow path of the shield gas is biased in the internal space of the torch body or the chip body. When the shield gas flow path in the internal space is biased, the gas flow ejected from the tip of the nozzle becomes a biased flow state. As a result, the gas shielding property at the time of welding is lowered, which adversely affects the welding quality. Further, the torch body may have a curved portion so that the operator can easily work. In this case, the coil liner tends to follow the inner surface of the outwardly bulging portion in the curved portion, and the shield gas flow path is biased. It is easy to occur.

Japanese Unexamined Patent Publication No. 2010-214412

The present invention has been conceived under such circumstances, and in a configuration in which a coil liner is arranged in the internal space of the torch body and the chip body and a shield gas flows in the internal space, the above-mentioned internal structure is used. The main task is to provide a welding torch suitable for reducing the bias of the shield gas flow path in the space and improving the gas shielding property at the time of welding.

In order to solve the above problems, the following technical means are adopted in the present invention.

The welding torch provided by the present invention is configured by spirally winding a tubular torch body, a tubular tip body attached to the tip of the torch body, and a metal wire, and the torch body and the above torch body. It is arranged in the internal space of the chip body and includes a coil liner for passing a welding wire, and the internal space is a flow path through which a shield gas flows, and the coil liner, the torch body, and the chip body are provided. At least one of the above has an overhanging portion overhanging such that the torch body or the chip body and the coil liner are closer or in contact with each other than the other parts.

In a preferred embodiment, the overhanging portion comprises an outer overhanging portion of the coil liner having a larger outer diameter than the other portions.

In a preferred embodiment, the overhanging portion includes an inward overhanging portion in the torch body or the chip body that juts out radially inward from the inner peripheral surface thereof.

In a preferred embodiment, the medial overhang is a portion of the torch body or chip body that has been press-fitted to occupy a portion of the interior space.

In a preferred embodiment, the overhanging portions are provided at a plurality of positions separated from each other in the axial direction of the coil liner.

According to the welding torch according to the present invention, by having the overhanging portion, the arrangement of the coil liner is prevented from being biased with respect to the inner peripheral surface of the torch body or the chip body, and the coil liner is between the inner peripheral surface. Is formed with gaps almost evenly in the circumferential direction of the inner peripheral surface. As a result, the bias of the shield gas flow path in the internal space of the torch body or the chip body is reduced, and the gas shielding property at the time of welding is improved. As a result, improvement of welding quality can be expected.

Other features and advantages of the invention will be more apparent by the detailed description given below with reference to the accompanying drawings.

A first embodiment of the welding torch according to the present invention is shown, and a part thereof is shown in a vertical sectional view. FIG. 3 is a vertical cross-sectional view of a main part of the welding torch shown in FIG. 1. It is a partially enlarged view of FIG. FIG. 3 is a vertical cross-sectional view of a main part showing a first modification of the welding torch according to the first embodiment shown in FIG. FIG. 3 is a vertical cross-sectional view of a main part showing a second modification of the welding torch according to the first embodiment shown in FIG. It is a main part vertical sectional view which shows the 2nd Embodiment of the welding torch which concerns on this invention. It is a vertical sectional view of the main part which shows the 3rd Embodiment of the welding torch which concerns on this invention. FIG. 7 is a partially enlarged cross-sectional view taken along the line VIII-VIII of FIG. It is a vertical sectional view of the main part which shows the 4th Embodiment of the welding torch which concerns on this invention. It is a vertical sectional view of the main part which shows the 5th Embodiment of the welding torch which concerns on this invention. It is a partially enlarged view of FIG.

Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings.

1 and 2 show a first embodiment of a welding torch according to the present invention. The welding torch A1 of the present embodiment includes a handle 1, a torch body 2, a tip body 3, an insulator 4, an orifice member 5, a nozzle 6, a feeding tip 7, and a coil liner 8. Will be done.

The handle 1 is a portion for the operator to grasp by hand. The torch switch 11 is an operation portion for an operator to operate the start / stop of welding. Since the handle 1 is not an essential part of the present invention, most of the description is omitted.

The torch body 2 has a cylindrical shape, and the base end portion is held by the handle 1. In the example shown in FIG. 1, the torch body 2 has a curved portion so that an operator can easily perform a welding operation. As shown in FIG. 2, the tip of the torch body 2 has a cylindrical inner peripheral surface 21.

The tip body 3 has a cylindrical shape and is attached to the tip of the torch body 2. The chip body 3 has a cylindrical inner peripheral surface 31. The tip body 3 is attached to the tip of the torch body 2 by a screw means 32. The chip body 3 is also made of a conductive metal and receives a welding current from the torch body 2. In the example shown in FIG. 2, the inner diameter of the inner peripheral surface 31 of the chip body 3 is about the same as the inner diameter of the inner peripheral surface 21 of the torch body 2. The inner diameter of the inner peripheral surface 31 and the inner diameter of the inner peripheral surface 21 may be different. A tapered portion 34 is formed in the vicinity of the tip portion of the chip body 3. The tapered portion 34 has a tapered shape that shrinks in diameter toward the tip of the chip body 3.

The insulator 4 has a cylindrical shape and is fitted on the outer surface of the axial intermediate portion of the chip body 3. In this embodiment, the insulator 4 includes an insulating bush 41 and a base 42. The insulating bush 41 is formed of, for example, an insulating member such as a heat-resistant hard resin, and is connected to the chip body 3 by a screwing means 411.

The base 42 is externally fitted and fixed to the insulating bush 41 from the base end side to the tip end side of the insulating bush 41. The base 42 is made of a metal such as brass. A male screw portion 421 is formed on the outer peripheral portion on the tip end side of the base 42. The male threaded portion 421 is configured as, for example, a trapezoidal thread.

The orifice member 5 is fitted on the outer surface of the tip portion in the axial direction of the chip body 3. The orifice member 5 is arranged so as to be adjacent to the insulator 4 in the axial direction of the chip body 3. The orifice member 5 will be described later.

The power feeding chip 7 is attached to the tip of the chip body 3. The base end of the feeding chip 7 is attached to the chip body 3 by a screwing means 71. A wire insertion hole 72 for passing a welding wire is formed in the feeding tip 7 so as to penetrate from the base end to the tip end. At the base end of the feeding tip 7, the wire insertion hole 72 has a tapered shape, and the welding wire (not shown) fed to the welding torch A1 is centered and guided by the tapered portion while being guided by the tip of the feeding tip 7. Sent to the side.

The nozzle 6 is a tubular member that forms an annular space that opens forward on the outside of the chip body 3 or the feeding chip 7. A female threaded portion 61 is formed on the inner peripheral portion on the base end side of the nozzle 6. The female threaded portion 61 can be screwed into the male threaded portion 421 of the insulator 4 (base 42), and is screwed with the male threaded portion 321. The nozzle 6 is attached to the insulator 4 (base 42) by being combined.

The coil liner 8 is arranged in the internal space S of the torch body 2 and the chip body 3. The coil liner 8 is formed by spirally winding a metal wire rod. The coil liner 8 is inserted from the base end side of the torch body 2 and arranged in the internal space S of the torch body 2 and the chip body 3. A predetermined gap is provided between the coil liner 8 and the inner peripheral surface 21 of the torch body 2 and between the coil liner 8 and the inner peripheral surface 31 of the chip body 3. The coil liner 8 extends close to the feeding chip 7, and in the illustrated example, the tip of the coil liner 8 is in close proximity to or in contact with the tapered portion 34 of the chip body 3. The welding wire (not shown) fed to the welding torch A1 passes through the wire insertion hole 72 of the feeding tip 7 while being guided through the inside of the coil liner 8 in the internal space S of the torch body 2 and the tip body 3. , Derived from the tip of the feeding chip 7.

In this embodiment, the coil liner 8 has a large diameter portion 81. The large diameter portion 81 is a portion of the coil liner 8 having an outer diameter larger than that of the other portions. In the example shown in FIG. 2, the large diameter portion 81 is located inside the chip body 3 and projects so as to be close to or in contact with the inner peripheral surface 31 of the chip body 3. The large-diameter portion 81 having such a configuration corresponds to an example of the outer overhanging portion (overhanging portion) of the present invention. Further, as described above, the tip of the coil liner 8 is in contact with the tapered portion 34 of the chip body 3. The tapered portion 34 is a portion of the chip body 3 that projects inward in the radial direction from the inner peripheral surface 31 thereof. This tapered portion 34 corresponds to an example of the inner overhanging portion (overhanging portion) of the present invention.

To give an example of the dimensions of the torch body 2, the chip body 3, and the coil liner 8, as shown in FIG. 3, the inner peripheral dimension D1 of the inner peripheral surface 21 of the torch body 2 and the inner peripheral surface 31 of the chip body 3 is 7 mm. The outer diameter dimension D2 of the coil liner 8 is about 6 mm. Further, the gap L1 between the outer peripheral portion of the coil liner 8 and the inner peripheral surfaces 21 and 31 of the torch body 2 and the chip body 3 is about 0.5 mm. The large diameter portion 81 of the coil liner 8 has an outer diameter dimension Dmax of about 6.8 to 7 mm. The gap L2 between the large diameter portion 81 (outer peripheral portion) and the inner peripheral surface 31 of the chip body 3 is about 0 to 0.1 mm, which is very small. The diameter d3 (wire diameter) of the metal wire wound spirally in the coil liner 8 is, for example, about 1.6 mm, and the gap L3 between adjacent metal wires is, for example, about 0 to 0.5 mm. be. However, each of the above dimensions is an example, and the dimensions of each part are not limited to the above-exemplified dimensional values.

The welding torch A1 is also configured to eject a shield gas made of an inert gas or the like from the nozzle 6 at the tip. Specifically, an annular hole 51 is formed on the inner circumference of the orifice member 5 to form an annular space 52 between the annular hole 51 and the outer surface of the chip body 3, and the annular space 52 and the inner space of the nozzle 6 are provided by the orifice hole 53. Communicate. Further, the chip body 3 is formed with a ventilation hole 33 for communicating the internal space S and the annular space 52. When the shield gas is sent to the welding torch A1, the shield gas passes through the internal space S of the torch body 2 and the chip body 3 and passes through the ventilation hole 33, the annular space 52 of the orifice member 5, or the nozzle 6 from the orifice hole 53. It is sent to the inner space of the nozzle 6 and finally ejected from the tip of the nozzle 6.

The internal space S of the torch body 2 and the chip body 3 has a role as a flow path through which the shield gas flows. Further, since the coil liner 8 is arranged in the internal space S of the torch body 2 and the chip body 3, the shield gas mainly includes the coil liner 8 and the inner peripheral surfaces 21 and 31 of the torch body 2 and the chip body 3. It flows through the gap provided between them.

Next, the operation of this embodiment will be described.

In the present embodiment, the coil liner 8 is arranged in the internal space S of the torch body 2 and the chip body 3. The internal space S has a role of a gas flow path through which the shield gas flows, and as described above, the shield gas is mainly between the coil liner 8 and the inner peripheral surfaces 21 and 31 of the torch body 2 and the chip body 3. It flows through the gap provided in. The coil liner 8 has a large diameter portion 81, and the large diameter portion 81 is a portion of the coil liner 8 having an outer diameter larger than that of other portions and projecting so as to be close to or in contact with the chip body 3. .. According to such a configuration, the arrangement of the coil liner 8 is prevented from being biased with respect to the inner peripheral surface 31 of the chip body 3, and the inner peripheral surface 31 is between the coil liner 8 and the inner peripheral surface 31. Gap is formed almost evenly in the circumferential direction of. As a result, the bias of the shield gas flow path in the internal space S is reduced, and the gas shielding property at the time of welding is improved. As a result, improvement of welding quality can be expected.

The chip body 3 has a tapered portion 34. The tapered portion 34 is a portion of the chip body 3 that projects radially inward from the inner peripheral surface 31 thereof, and the tip of the coil liner 8 is close to or in contact with the tapered portion 34. According to such a configuration, the bias of the shield gas flow path in the internal space S is appropriately reduced in the vicinity of the tip portion of the chip body 3.

In the present embodiment, the large diameter portion 81 and the tapered portion 34 are provided at a plurality of locations (two locations in the present embodiment) that are separated from each other in the axial direction (vertical direction in FIG. 2) of the coil liner 8. As a result, the centering effect of the coil liner 8 on the inner peripheral surface 31 is appropriately exhibited. This is preferable in reducing the bias of the shield gas flow path in the internal space S and improving the gas shielding property at the time of welding.

Regarding the large diameter portion 81 of the coil liner 8, in the example shown in FIG. 3, the gap between the large diameter portion 81 (outer peripheral portion) and the inner peripheral surface 31 of the chip body 3 is small, and the large diameter portion 81. Shown the case where is close to the inner peripheral surface 31. In the present invention, "proximity" means between the large diameter portion 81 (outer peripheral portion) and the inner peripheral surface 31 when the axis of the coil liner 8 and the axis of the chip body 3 (inner peripheral surface 31) coincide with each other. It means that there is a uniform gap in the circumferential direction. When the welding torch A1 is used, if the axis of the coil liner 8 deviates slightly from the axis of the chip body 3 (inner peripheral surface 31), a part of the large diameter portion 81 (outer peripheral portion) comes into contact with the inner peripheral surface 31 and the coil. The centering effect of the liner 8 can be obtained.

Unlike the example shown in FIG. 3, the large diameter portion 81 may be in contact with the inner peripheral surface 31. In the present invention, "contact" means a gap between the large diameter portion 81 (outer peripheral portion) and the inner peripheral surface 31 when the axis of the coil liner 8 and the axis of the chip body 3 (inner peripheral surface 31) coincide with each other. It means a state of contact without contact. When the large diameter portion 81 abuts on the inner peripheral surface 31, for example, the outer diameter dimension of the large diameter portion 81 in a natural state is set to be slightly larger than the inner diameter dimension of the inner peripheral surface 31, and the coil liner 8 is set to the torch body. When the 2 and the chip body 3 are inserted into the internal space S, the large diameter portion 81 (outer peripheral portion) is in sliding contact with the inner peripheral surfaces 21 and 31.

The number of turns of the large diameter portion 81 of the coil liner 8 is not particularly limited, but is, for example, about 1 to 3 turns. As the number of turns of the large diameter portion 81 increases, the flow path resistance of the shield gas flow path increases in the internal space S. Further, when the large diameter portion 81 comes into contact with the inner peripheral surface 31, if the number of turns of the large diameter portion 81 increases, the sliding resistance of the large diameter portion 81 increases when the coil liner 8 is set, which is not preferable.

In the present embodiment, the tip portion of the chip body 3 has a tapered portion 34, but the configuration may not have such a tapered portion 34. The point that the chip body 3 may be configured not to have the tapered portion 34 is the same in the modified examples and other embodiments described later.

FIG. 4 shows a first modification of the welding torch according to the first embodiment. In the drawings after FIG. 4, the same or similar elements as those in the first embodiment are designated by the same reference numerals as those in the first embodiment, and the description thereof will be omitted as appropriate.

In the welding torch A11 shown in FIG. 4, the arrangement of the large diameter portion 81 in the coil liner 8 is different from that of the above embodiment. In the welding torch A11, two large diameter portions 81 are provided inside the chip body 3.

Also in the welding torch A11 of this modification, the arrangement of the coil liner 8 is prevented from being biased with respect to the inner peripheral surface 31 of the chip body 3, and the inner peripheral surface is between the coil liner 8 and the inner peripheral surface 31. Gap is formed almost evenly in the circumferential direction of the surface 31. As a result, the bias of the shield gas flow path in the internal space S is reduced, and the gas shielding property at the time of welding is improved. As a result, improvement of welding quality can be expected.

In this modification, the large diameter portion 81 and the tapered portion 34 are provided at a plurality of locations (three locations in the present embodiment) that are separated from each other in the axial direction (vertical direction in FIG. 4) of the coil liner 8. As a result, the centering effect of the coil liner 8 on the inner peripheral surface 31 is appropriately exhibited. This is more preferable in reducing the bias of the shield gas flow path in the internal space S and improving the gas shielding property at the time of welding.

FIG. 5 shows a second modification of the welding torch according to the first embodiment. In the welding torch A12 shown in FIG. 5, the arrangement of the large diameter portion 81 in the coil liner 8 is different from that of the above embodiment. In the welding torch A12, one large diameter portion 81 is provided inside the torch body 2 and inside the chip body 3.

In the welding torch A12 of this modification, the arrangement of the coil liner 8 is prevented from being biased with respect to the inner peripheral surface 21 of the torch body 2 and the inner peripheral surface 31 of the chip body 3, and the coil liner 8 and the inner peripheral surface 21, A gap is formed between the inner peripheral surfaces 21 and 31 almost evenly in the circumferential direction. As a result, the bias of the shield gas flow path in the internal space S is reduced, and the gas shielding property at the time of welding is improved. As a result, improvement of welding quality can be expected.

In this modification, the large diameter portion 81 and the tapered portion 34 are provided at a plurality of locations (three locations in the present embodiment) separated from each other in the coil liner 8 (vertical direction in FIG. 5). As a result, the centering effect of the coil liner 8 on the inner peripheral surfaces 21 and 31 is appropriately exhibited. This is more preferable in reducing the bias of the shield gas flow path in the internal space S and improving the gas shielding property at the time of welding.

In the welding torch A12, the large diameter portion 81 is provided corresponding to the inner peripheral surface 21 of the straight portion near the tip of the torch body 2, but the large diameter portion 81 corresponds to the inner peripheral surface 21 of the curved portion of the torch body 2. A portion 81 may be provided.

FIG. 6 shows a second embodiment of the welding torch according to the present invention. In the welding torch A2 shown in FIG. 6, the configurations of the coil liner 8 and the chip body 3 are different from those of the first embodiment.

In the present embodiment, the coil liner 8 does not have a large diameter portion 81, and has a substantially uniform outer diameter dimension over the entire length. The chip body 3 has a reduced diameter portion 35. The reduced diameter portion 35 is a portion of the chip body 3 that projects inward in the radial direction from the inner peripheral surface 31 thereof. In the example shown in FIG. 6, the diameter-reduced portion 35 has an annular shape and is in close proximity to or in contact with the outer peripheral portion of the coil liner 8. The reduced diameter portion 35 having such a configuration corresponds to an example of the inner overhanging portion (overhanging portion) of the present invention.

According to the configuration in which the chip body 3 has the reduced diameter portion 35, the arrangement of the coil liner 8 is prevented from being biased with respect to the inner peripheral surface 31 of the chip body 3, and the coil liner 8 and the inner peripheral surface 31 are combined. Between them, gaps are formed almost evenly in the circumferential direction of the inner peripheral surface 31. As a result, the bias of the shield gas flow path in the internal space S is reduced, and the gas shielding property at the time of welding is improved. As a result, improvement of welding quality can be expected.

In the present embodiment, the reduced diameter portion 35 and the tapered portion 34 are provided at a plurality of locations (two locations in the present embodiment) that are separated from each other in the axial direction (vertical direction in FIG. 6) of the coil liner 8. As a result, the centering effect of the coil liner 8 on the inner peripheral surface 31 is appropriately exhibited. This is preferable in reducing the bias of the shield gas flow path in the internal space S and improving the gas shielding property at the time of welding.

In the example shown in FIG. 6, the tip body 3 has a reduced diameter portion 35, but for example, the inner peripheral surface 21 of the straight portion near the tip of the torch body 2 has the same reduced diameter portion 35 as the above-mentioned reduced diameter portion 35. A reduced diameter portion of the configuration may be provided.

7 and 8 show a third embodiment of the welding torch according to the present invention. In the welding torch A3 shown in FIGS. 7 and 8, the structure of the chip body 3 is different from that of the welding torch A2 of the second embodiment.

In the present embodiment, the coil liner 8 does not have the large diameter portion 81 as in the second embodiment, and has a substantially uniform outer diameter over the entire length. On the other hand, the chip body 3 has an inner projection 36 and a groove 37 instead of the diameter-reduced portion 35 of the second embodiment.

The inner surface protrusion 36 is a portion of the chip body 3 that projects inward in the radial direction from the inner peripheral surface 31 thereof. In this embodiment, as shown in FIG. 8, a plurality of inner surface protrusions 36 are arranged at equal intervals in the circumferential direction of the chip body 3. The groove 37 is a space sandwiched between adjacent inner protrusions 36. As shown in FIG. 7, the inner surface projection 36 of the present embodiment has a longer length (vertical length in the figure) along the axial direction of the chip body 3 than the reduced diameter portion 35 of the second embodiment. Has been done.

According to the configuration in which the chip body 3 has the inner surface protrusion 36 and the groove 37, the arrangement of the coil liner 8 is prevented from being biased with respect to the inner peripheral surface 31 of the chip body 3, and the coil liner 8 and the inner peripheral surface 31 are prevented from being biased. A gap is formed between the two and the inner peripheral surface 31 almost evenly in the circumferential direction. As a result, the bias of the shield gas flow path in the internal space S is reduced, and the gas shielding property at the time of welding is improved. As a result, improvement of welding quality can be expected.

The inner projection 36 has a relatively long length along the axial direction of the chip body 3. Therefore, the centering effect of the coil liner 8 can be obtained in a long range along the axial direction of the coil liner 8. On the other hand, a groove 37 is formed between the adjacent inner protrusions 36. As a result, the shield gas flowing through the internal space S can pass through each groove 37 between the adjacent inner surface protrusions 36 at the formation site of the inner surface protrusion 36. Therefore, it is possible to suppress an increase in the flow path resistance of the shielded gas flow path.

In the present embodiment, the inner surface projection 36 and the tapered portion 34 are provided at a plurality of locations (two locations in the present embodiment) that are separated from each other in the axial direction (vertical direction in FIG. 7) of the coil liner 8. As a result, the centering effect of the coil liner 8 on the inner peripheral surface 31 is appropriately exhibited. This is preferable in reducing the bias of the shield gas flow path in the internal space S and improving the gas shielding property at the time of welding.

In the example shown in FIGS. 7 and 8, the tip body 3 has the inner surface protrusion 36, but for example, the inner peripheral surface 21 of the straight portion near the tip of the torch body 2 has the same inner surface protrusion 36 as the above-mentioned inner surface protrusion 36. An inner projection of the configuration may be provided.

FIG. 9 shows a fourth embodiment of the welding torch according to the present invention. In the welding torch A4 shown in FIG. 9, the configuration of the chip body 3 is different from that of the welding torch A2 of the second embodiment.

In the present embodiment, the coil liner 8 does not have the large diameter portion 81 as in the second embodiment, and has a substantially uniform outer diameter over the entire length. On the other hand, the chip body 3 has a press-fitting portion 38 instead of the diameter-reduced portion 35 of the second embodiment. The press-fitting portion 38 has an annular shape and is a portion press-fitted into the inner peripheral surface 31 of the chip body 3. Before press-fitting into the chip body 3, the outer diameter dimension of the press-fitting portion 38 is slightly larger than the inner diameter dimension of the inner peripheral surface 31. The press-fitting portion 38 projects inward in the radial direction from the inner peripheral surface 31 of the chip body 3, and is in close proximity to or in contact with the outer peripheral portion of the coil liner 8. The press-fitting portion 38 having such a configuration corresponds to an example of the inner overhanging portion (overhanging portion) of the present invention.

According to the configuration in which the chip body 3 has the press-fitting portion 38 described above, the arrangement of the coil liner 8 is prevented from being biased with respect to the inner peripheral surface 31 of the chip body 3, and the space between the coil liner 8 and the inner peripheral surface 31 is prevented. In the circumferential direction of the inner peripheral surface 31, gaps are formed almost evenly. As a result, the bias of the shield gas flow path in the internal space S is reduced, and the gas shielding property at the time of welding is improved. As a result, improvement of welding quality can be expected.

In the present embodiment, the press-fitting portion 38 and the tapered portion 34 are provided at a plurality of locations (two locations in the present embodiment) that are separated from each other in the axial direction (vertical direction in FIG. 9) of the coil liner 8. As a result, the centering effect of the coil liner 8 on the inner peripheral surface 31 is appropriately exhibited. This is preferable in reducing the bias of the shield gas flow path in the internal space S and improving the gas shielding property at the time of welding.

In the example shown in FIG. 9, the press-fitting portion 38 was press-fitted into the inner peripheral surface 31 of the chip body 3, but for example, the press-fitting portion 38 was press-fitted into the inner peripheral surface 21 of the straight portion near the tip of the torch body 2. A press-fitting portion having the same structure as that of the portion 38 may be press-fitted.

10 and 11 show a fifth embodiment of the welding torch according to the present invention. In the welding torch A5 shown in FIG. 10, the specific configuration of the chip body 3 is different from that of the welding torch A4 of the fourth embodiment.

In the present embodiment, the coil liner 8 does not have the large diameter portion 81 as in the fourth embodiment, and has a substantially uniform outer diameter over the entire length. Further, the chip body 3 has a press-fitting portion 38 as in the fourth embodiment, but in the present embodiment, the press-fitting portion 38 is press-fitted into the press-fitting seat 39. The press-fitting seat 39 is a portion that slightly protrudes inward in the radial direction from the inner peripheral surface 31 of the chip body 3. Before press-fitting into the chip body 3, the outer diameter dimension of the press-fitting portion 38 is slightly larger than the inner diameter dimension of the press-fitting seat 39 and smaller than the inner diameter dimension of the inner peripheral surface 31. The press-fitting portion 38 projects inward in the radial direction from the inner peripheral surface 31 of the chip body 3, and is in close proximity to or in contact with the outer peripheral portion of the coil liner 8. This press-fitting portion 38 corresponds to an example of the inner overhanging portion (overhanging portion) of the present invention.

According to the configuration in which the chip body 3 has the press-fitting portion 38 described above, the arrangement of the coil liner 8 is prevented from being biased with respect to the inner peripheral surface 31 of the chip body 3, and the space between the coil liner 8 and the inner peripheral surface 31 is prevented. In the circumferential direction of the inner peripheral surface 31, gaps are formed almost evenly. As a result, the bias of the shield gas flow path in the internal space S is reduced, and the gas shielding property at the time of welding is improved. As a result, improvement of welding quality can be expected.

In the present embodiment, the press-fitting portion 38 and the tapered portion 34 are provided at a plurality of locations (two locations in the present embodiment) that are separated from each other in the axial direction (vertical direction in FIG. 10) of the coil liner 8. As a result, the centering effect of the coil liner 8 on the inner peripheral surface 31 is appropriately exhibited. This is preferable in reducing the bias of the shield gas flow path in the internal space S and improving the gas shielding property at the time of welding.

Further, in the present embodiment, the press-fitting portion 38 is press-fitted into the press-fitting seat 39 protruding inward in the radial direction from the inner peripheral surface 31. According to such a configuration, the press-fitting portion 38 can be accurately arranged at a predetermined position (a position where the press-fitting seat 39 is provided).

Although the configuration example of the press-fitting seat 39 having an annular shape is shown, the configuration of the press-fitting seat 39 is not limited to this. For example, in the circumferential direction of the chip body 3, a plurality of press-fitting seats 39 separated from each other may be formed at intervals.

Further, in the examples shown in FIGS. 10 and 11, the press-fitting seat 39 protruding from the inner peripheral surface 31 of the chip body 3 was provided, and the press-fitting portion 38 was press-fitted into the press-fitting seat 39. A press-fitting seat that protrudes from the inner peripheral surface 21 of the straight portion near the tip of the torch body 2 may be formed, and a press-fitting portion having the same configuration as that of the press-fitting portion 38 may be press-fitted into the press-fitting seat.

Although the embodiments of the present invention have been described above, the scope of the present invention is not limited to the above-described embodiments, and any changes within the scope of the matters described in each claim are the scope of the present invention. Is included in.

A1, A11, A12, A2, A3, A4, A5: Welding torch, 2: Torch body, 21: Inner peripheral surface, 3: Chip body, 31: Inner peripheral surface, 34: Tapered part (overhanging part, inner overhanging part) ), 35: Reduced diameter part (overhanging part, inner overhanging part), 36: Inner surface protrusion (overhanging part, inner overhanging part), 38: Press-fitting part (overhanging part, inner overhanging part), 8: Coil liner, 81: Large Diameter (overhanging part, outer overhanging part), S: Internal space

Claims (5)

With a tubular torch body,
The tubular tip body attached to the tip of the torch body and
It is configured by spirally winding a metal wire and is arranged in the internal space of the torch body and the chip body, and is provided with a coil liner for passing a welding wire.
The above internal space is a flow path through which the shield gas flows.
At least one of the coil liner, the torch body and the chip body has a welded torch having an overhang so that the torch body or the chip body and the coil liner project closer to or in contact with each other than the other parts. .. The welding torch according to claim 1, wherein the overhanging portion includes an outer overhanging portion having an outer diameter larger than that of other portions in the coil liner. The welding torch according to claim 1 or 2, wherein the overhanging portion includes an inner overhanging portion that projects inward in the radial direction from the inner peripheral surface of the torch body or the chip body. The welding torch according to claim 3, wherein the inner overhanging portion is a portion press-fitted in the torch body or the tip body. The welding torch according to any one of claims 1 to 4, wherein the overhanging portions are provided at a plurality of positions separated from each other in the axial direction of the coil liner.

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