Nozzle attachment of welding torch

Abstract

To provide a nozzle attachment of a welding torch which enables reduction of a use amount of a shield gas by generating a swirl flow in an existing welding torch and recovers the generation of the swirl flow at minimum costs when generation of the swirl flow is hindered by accumulation of welding spatter adhering thereto.SOLUTION: A nozzle attachment 12 is detachably attached to a nozzle 4 of a welding torch 1 which includes a rod-like chip 3 which sends a welding wire 2 from the tip, and the cylindrical nozzle 4 which encloses the periphery of the chip 3, and jets a shield gas G flowing between the nozzle 4 and the chip 3 from the opening 5 of the nozzle 4 to a welding portion 7 to perform arc welding. The nozzle attachment 12 includes: a cylindrical insertion cylinder part 13 which is detachably inserted from the opening 5 of the nozzle 4 so as to contact with the inner peripheral surface of the nozzle 4; and a spiral part 14 which is formed spirally on the inner peripheral surface of the insertion cylinder part 13 to provide a swirl flow to the shield gas G flowing between the insertion cylinder part 13 and the chip 3.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a nozzle attachment that is detachably attached to the nozzle of a welding torch, and more particularly to a nozzle attachment for a welding torch that can efficiently reduce the consumption of shielding gas sprayed from the nozzle toward the welding point of members to be welded. [Background technology]

[0002] As shown in FIG. 1, a welding torch 1 used for arc welding has a rod-shaped tip 3 that feeds a welding wire 2 from its tip, and a cylindrical nozzle 4 that surrounds the tip 3. A shielding gas G (e.g., CO2 gas) is passed between the nozzle 4 and the tip 3 and sprayed from an opening 5 of the nozzle 4 to a welding point 7 of a workpiece 6 to perform arc welding.

[0003] That is, while the welding wire 2 is fed from the tip of the tip 3 toward a groove 8 formed at a welding point 7 of the workpiece 6, a voltage is applied between the welding wire 2 and the workpiece 6 to generate an arc 9, and the groove 8 is melted together with the welding wire 2. At this time, if the molten metal at the welding point 7 comes into contact with air, it will cause a welding defect, so the shielding gas G ejected from the ejection port 11 of the orifice 10 attached to the base end of the tip 3 is caused to flow between the tip 3 and the nozzle 4 and ejected from the opening 5 of the nozzle 4 toward the welding point 7, thereby preventing the molten metal at the welding point 7 from coming into contact with the air.

[0004] However, as shown in Fig. 1, the inner peripheral surface of the nozzle 4 of a typical welding torch 1 is a smooth cylinder, so that the shielding gas G flowing between the nozzle 4 and the tip 3 diffuses in all directions as indicated by the dashed arrows G immediately after being ejected from the opening 5 of the nozzle 4, diluting the gas concentration of the shielding gas G at the welding point 7 and reducing the shielding effect. In addition, when the shielding gas G diffuses from the opening 5 of the nozzle 4, the momentum (inertial force) of the gas G toward the welding point 7 decreases, and there is a risk that the gas G will not properly reach the welding point 7 due to external factors such as wind. This raises concerns about a decrease in welding quality.

[0005] As a result, in order to obtain a shielding effect that can ensure appropriate welding quality, a large amount of shielding gas G needs to be sprayed from the opening 5 of the nozzle 4, which increases the amount of shielding gas G used and causes an increase in costs. In addition, if a greenhouse gas such as CO2 gas is used as the shielding gas G, this will have an adverse effect on global environmental protection.

[0006] As a countermeasure to this problem, a spiral groove is formed on the inner surface of the nozzle 4 of the welding torch 1, and a swirling flow is imparted to the shielding gas G, thereby suppressing the spread of the shielding gas G and achieving a high shielding effect (see Patent Document 1). [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2021-186836 A Summary of the Invention [Problem to be solved by the invention]

[0008] However, since the spiral groove of the document 1 is formed on the inner peripheral surface of the nozzle of the welding torch itself, it cannot be applied to the nozzle 4 of the existing welding torch 1 as shown in FIG. 1, and a swirling flow cannot be generated in the existing welding torch 1 afterwards. Therefore, it is not possible to reduce the amount of shielding gas G used for the existing welding torch 1. In addition, when used for a long time, it is considered that the spatter scattered during welding adheres to and accumulates on the spiral groove formed on the inner peripheral surface of the nozzle 4, preventing the generation of the swirling flow. In this case, in order to restore an appropriate swirling flow, it is necessary to remove the nozzle 4 from the welding torch 1 and replace it with a new one, which is unavoidable at a certain cost.

[0009] The object of the present invention, which was devised in consideration of the above circumstances, is to provide a nozzle attachment for a welding torch that can be retrofitted to an existing welding torch to generate a swirling flow for the existing welding torch, thereby reducing the amount of shielding gas used, and that can restore the generation of a swirling flow at minimal cost when the generation of a swirling flow is hindered by the deposition and accumulation of welding spatter. [Means for solving the problem]

[0010] According to the present invention, which has been devised to achieve the above-mentioned object, there is provided a nozzle attachment that is detachably attached to the nozzle of a welding torch which has a rod-shaped tip that feeds out a welding wire from its tip and a cylindrical nozzle surrounding the tip, and which performs arc welding by spraying shielding gas flowing between the nozzle and the tip from an opening of the nozzle to a welding point, the nozzle attachment being characterized in having a cylindrical insertion tube portion that is detachably inserted from the nozzle opening so as to contact the inner surface of the nozzle, and a helical portion formed in a helical shape on the inner surface of the insertion tube portion to impart a swirling flow to the shielding gas flowing between the insertion tube portion and the tip.

[0011] In the nozzle attachment for a welding torch according to the present invention, the helical portion may be formed so that the helical pitch becomes narrower from the upstream side to the downstream side of the shielding gas flowing between the insertion tube portion and the tip.

[0012] In the nozzle attachment of the welding torch according to the present invention, the spiral portion may be formed so that the height of the peaks constituting the spiral portion increases from the upstream side to the downstream side of the shielding gas flowing between the insertion tube portion and the tip, and the inner diameter of the insertion tube portion at the top of the peaks gradually decreases.

[0013] In the nozzle attachment for a welding torch according to the present invention, a gripping portion is provided at the tip of the insertion tube portion to be gripped by the fingers of an operator when inserting the insertion tube portion into the opening of the nozzle of the welding torch, and the gripping portion may have a flange portion extending radially outward from the tip of the insertion tube portion, and an outer tube portion extending in the axial direction of the insertion tube portion from the outer edge of the flange portion so as to contact the outer peripheral surface of the nozzle.

[0014] In the nozzle attachment for a welding torch according to the present invention, the materials of the insertion tube portion, the spiral portion and the grip portion may be a material to which spatter scattered during welding is less likely to adhere than the material of the nozzle.

[0015] In the nozzle attachment for a welding torch according to the present invention, the insertion tube portion, the spiral portion and the grip portion may be made of a material selected from the group consisting of stainless steel with an insulating coating, silicone rubber, resin and ceramic. Effect of the Invention

[0016] The nozzle attachment for a welding torch according to the present invention can provide the following effects. (1) By inserting the nozzle attachment into the nozzle of the welding torch, the shielding gas ejected from the nozzle opening toward the welding point is made to swirl, so that the shielding gas ejected from the nozzle opening can be made to swirl even for existing welding torches. The shielding gas ejected from the nozzle opening as a swirling flow reaches the welding point without diffusing, effectively maintaining the required concentration, so deterioration of welding quality can be suppressed. In addition, the effects of external factors such as wind can be reduced. (2) The nozzle attachment's insertion tube is inserted into the nozzle of the welding torch so that it touches its inner circumferential surface, so the cross-sectional area of ​​the flow path for the shielding gas inside the nozzle is narrowed by the thickness of the insertion tube. This increases the flow rate of the shielding gas ejected from the nozzle opening, so that the required concentration of the shielding gas can be maintained at the welding point even if the flow rate of the shielding gas is reduced, and the amount of shielding gas used can be reduced. (3) If, over time, spatter scattered during welding accumulates on the spiral portion of the inner surface of the nozzle attachment attached to the nozzle of the welding torch, preventing the proper generation of swirling flow, the generation of swirling flow can be restored by replacing only the nozzle attachment, without making any changes to the welding torch itself, including the nozzle. (4) In this way, by retrofitting the nozzle attachment to a welding torch, a swirling flow can be generated for an existing welding torch, thereby maintaining welding quality and reducing the amount of shielding gas used. In addition, if welding spatter adheres to and accumulates on the nozzle attachment, preventing the generation of a swirling flow, the swirling flow can be restored at minimal cost by replacing the nozzle attachment. [Brief description of the drawings]

[0017] [Figure 1] FIG. 2 is a cross-sectional view of a welding torch before a nozzle attachment according to the present invention is attached. [Diagram 2] 2 is a perspective view showing a state in which a nozzle attachment according to the present invention is attached to the welding torch of FIG. 1. FIG. [Diagram 3] 3 is a cross-sectional view taken along line III-III in FIG. 2, showing a cross-sectional view of a nozzle attachment according to one embodiment of the present invention. [Figure 4] 1 is a cross-sectional view of a welding torch to which a nozzle attachment according to an embodiment of the present invention is attached. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values ​​shown in the embodiment are merely examples for facilitating understanding of the invention, and do not limit the present invention unless otherwise specified. In this specification and drawings, elements having substantially the same functions and configurations are given the same reference numerals to avoid repeated explanations, and elements not directly related to the present invention are not illustrated.

[0019] (welding torch 1) 1 shows an example of a welding torch 1 to which a nozzle attachment according to an embodiment of the present invention is attached. As described above, this type of welding torch 1 includes a rod-shaped tip 3 that feeds a welding wire 2 from its front end and a cylindrical nozzle 4 that surrounds the tip 3, and is configured to spray a shielding gas G (e.g., CO2 gas) flowing between the nozzle 4 and the tip 3 from an opening 5 of the nozzle 4 to a welding point 7 to perform arc welding.

[0020] As shown in Fig. 1, welding torch 1 applies a voltage between welding wire 2 fed out from the end of tip 3 and workpiece 6 to generate arc 9, and melts groove 8 formed at welding point 7 of workpiece 6 together with welding wire 2. At this time, shielding gas G (e.g., CO2 gas, etc.) ejected from ejection port 11 of orifice 10 attached to the base end of tip 3 is sprayed toward welding point 7 from opening 5 of nozzle 4 to prevent the molten metal at welding point 7 from coming into contact with air.

[0021] (Nozzle Attachment 12) As shown in Fig. 2, a nozzle attachment 12 according to one embodiment of the present invention is freely attached to the nozzle 4 of the welding torch 1. As shown in Fig. 3 and Fig. 4, the nozzle attachment 12 according to this embodiment has a cylindrical insertion tube portion 13 that is detachably inserted from the opening 5 of the nozzle 4 of the welding torch 1 so as to contact the inner peripheral surface of the nozzle 4, and a spiral portion 14 formed in a spiral shape on the inner peripheral surface of the insertion tube portion 13 to impart a swirling flow to the shielding gas G (e.g., CO2 gas) flowing between the insertion tube portion 13 and the tip 3.

[0022] (Insertion tube portion 13) 4, the outer diameter of the insertion tube portion 13 of the nozzle attachment 12 is set to be slightly larger than the inner diameter of the nozzle 4 of the welding torch 1, so that it can be inserted into the nozzle 4 of the welding torch 1, and the outer peripheral surface of the insertion tube portion 13 is pressed against the inner peripheral surface of the nozzle 4 during insertion. This prevents the insertion tube portion 13 from falling out of the nozzle 4 when the welding torch 1 is stopped after welding is performed after insertion. The length of the insertion tube portion 13 is set so that it does not face the nozzle outlet 11 of the orifice 10 when the nozzle attachment 12 is properly attached to the nozzle 4.

[0023] (Gripping part 15) As shown in Fig. 2, the tip of the insertion tube 13 of the nozzle attachment 12 is provided with a grip 15 that is gripped by the fingers of an operator when the insertion tube 13 is inserted into the opening 5 of the nozzle 4 of the welding torch 1. As shown in Fig. 3, the grip 15 has a flange 15a extending radially outward from the tip of the insertion tube 13 and an outer tube 15b extending from the outer edge of the flange 15a in the axial direction of the insertion tube 13, and is inserted so that the tip of the nozzle 4 of the welding torch 1 abuts against a ring-shaped gap 15c formed between the outer tube 15b and the insertion tube 13 as shown in Fig. 4. The inner diameter of the outer tube 15b is set slightly smaller than the outer diameter of the nozzle 4, and the inner peripheral surface of the outer tube 15b is pressed against the outer peripheral surface of the nozzle 4 when inserted, so that the nozzle attachment 12 does not fall off the nozzle 4 during welding work.

[0024] (Spiral part 14) As shown in Figures 3 and 4, a helical portion 14 is formed on the inner peripheral surface of the insertion tube portion 13 along the axial direction. The helical portion 14 imparts a swirling flow to the shielding gas G that is ejected from the ejection port 11 of the orifice 10 and flows between the insertion tube portion 13 and the tip 3. When comparing the helical pitch P1 on the upstream side of the shielding gas G with the helical pitch P2 on the downstream side of the shielding gas G, P1>P2, and the helical pitch gradually narrows from the upstream side to the downstream side. In other words, the helical portion 14 is formed so that the helical pitch narrows from the upstream side to the downstream side of the shielding gas G flowing inside the insertion tube portion 13.

[0025] 3 and 4, when comparing an inner diameter D1 of the helical portion 14 at the height of the peaks (peaks constituting the helical portion 14) on the upstream side of the shielding gas G with an inner diameter D2 at the height of the peaks on the downstream side, D1>D2, and the inner diameter at the tops of the peaks gradually becomes smaller. That is, the helical portion 14 is formed so that the height of the peaks increases from the upstream side to the downstream side of the shielding gas G flowing inside the insertion tube portion 13, and the inner diameter of the insertion tube portion at the tops of the peaks gradually becomes smaller.

[0026] (Material) 2 and 4, the material of nozzle attachment 12 (insertion tube portion 13, spiral portion 14, grip portion 15) attached to nozzle 4 of welding torch 1 is a material to which spatter scattered during welding is less likely to adhere than the material of nozzle 4 of welding torch 1. For example, when nozzle 4 of welding torch 1 is made of carbon steel, nozzle attachment 12 is made of stainless steel with insulating coating (KCF (registered trademark)), silicone rubber, resin (heat-resistant resin), ceramic, or the like. KCF is a stainless steel material, a special stainless steel with an insulating coating formed on the surface by heat treatment.

[0027] (Action and effect) According to the nozzle attachment 12 of the welding torch 1 according to this embodiment, the following effects can be achieved.

[0028] As shown in Fig. 2, by inserting a nozzle attachment 12 into the nozzle 4 of the welding torch 1, a swirl is imparted to the shielding gas G (e.g., CO2 gas) ejected from the opening 5 of the nozzle 4 toward the welding point 7 as shown in Fig. 4, so that the shielding gas G ejected from the nozzle 5 can be made into a swirling flow even for existing welding torches 1. The shielding gas G ejected from the nozzle 4 as a swirling flow reaches the welding point 7 without diffusing, effectively maintaining the required concentration, so deterioration of welding quality can be suppressed. In addition, the effects of external factors such as wind can be reduced.

[0029] 4, the insertion tube portion 13 of the nozzle attachment 12 is inserted into the nozzle 4 of the welding torch 1 so as to contact its inner peripheral surface, so that the flow path cross-sectional area of ​​the shielding gas G inside the nozzle 4 is narrowed by the wall thickness of the insertion tube portion 13. Therefore, even if the flow rate of the shielding gas G ejected from the ejection port 11 of the orifice 10 is the same as before the nozzle attachment 12 was attached, the flow rate of the shielding gas G ejected from the nozzle 4 increases by attaching the nozzle attachment 12. Therefore, even if the flow rate of the shielding gas G is reduced, the concentration of the shielding gas at the welding point 7 can be maintained at the required concentration, and the amount of shielding gas G used can be reduced.

[0030] As shown in Figure 4, when welding work is performed using welding torch 1 equipped with nozzle attachment 12, it is considered that with age, spatter scattered during welding will adhere to and accumulate on spiral portion 14 of nozzle attachment 12 attached to nozzle 4 of welding torch 1, preventing proper generation of a swirling flow. In this case, the generation of a swirling flow can be restored by replacing only nozzle attachment 12 with a new one without making any changes to welding torch 1 itself, including nozzle 4, at low cost.

[0031] In this way, by retrofitting the nozzle attachment 12 according to this embodiment to the nozzle 4 of the welding torch 1, it is possible to generate a swirling flow for the existing welding torch 1, maintaining the welding quality while reducing the amount of shielding gas G used, and when welding spatter adheres to and accumulates on the nozzle attachment 12, preventing the generation of the swirling flow, the swirling flow can be restored at minimal cost by replacing only the nozzle attachment 12. Furthermore, when a greenhouse gas such as CO2 gas is used as the shielding gas G, the amount of CO2 gas and other emissions can be reduced, contributing to global warming countermeasures.

[0032] (Regarding the helical pitch of the helical portion 14) 3 and 4, in the nozzle attachment 12 of the welding torch 1 according to this embodiment, the helical portion 14 is formed so that the helical pitch becomes narrower (P1>P2) from the upstream side to the downstream side of the shielding gas G flowing between the insertion tube portion 13 and the tip 3. As a result, the swirling speed of the swirling flow of the shielding gas G ejected from the ejection port 11 of the orifice 10 gradually increases as it flows toward the tip side of the nozzle attachment 12, and the swirling speed when ejected from the tip of the nozzle attachment 12 can be effectively increased.

[0033] (Regarding the inner diameter of the helical pitch of the helical portion 14) 3 and 4, in the nozzle attachment 12 of the welding torch 1 according to this embodiment, the spiral portion 14 is formed so that the height of the peak increases and the inner diameter of the insertion tube portion at the peak gradually decreases (D1>D2) from the upstream side to the downstream side of the shielding gas G flowing between the insertion tube portion 13 and the tip 3. This produces a nozzle effect, and the axial speed of the shielding gas G ejected from the ejection port 11 of the orifice 10 gradually increases as it flows toward the tip side of the nozzle attachment 12, effectively increasing the axial speed when ejected from the tip of the nozzle attachment 12.

[0034] (Regarding the grip portion 15) As shown in Figs. 2 and 3, in the nozzle attachment 12 of the welding torch 1 according to this embodiment, a gripping portion 15 is provided at the tip of the insertion tube portion 13 to be gripped by the fingers of an operator when the insertion tube portion 13 is inserted into the opening 5 of the nozzle 4 of the welding torch 1. As shown in Figs. 3 and 4, the gripping portion 15 has a flange portion 15a extending radially outward from the tip of the insertion tube portion 13, and an outer tube portion 15b extending in the axial direction of the insertion tube portion 13 from the outer edge of the flange portion 15a so as to contact the outer circumferential surface of the nozzle 4. The gripping portion 15 functions as a member gripped by the fingers of an operator when the nozzle attachment 12 is attached to the nozzle 4 of the welding torch 1, and also functions as a cover that prevents spatters scattered during welding from adhering to the tip and outer circumferential surface of the nozzle 4, since the flange portion 15a and the outer tube portion 15b cover the tip and outer circumferential surface of the nozzle 4.

[0035] (About the material of the nozzle attachment 12) In the nozzle attachment 12 of the welding torch 1 according to this embodiment shown in Figures 3 and 4, the material of the entire nozzle attachment 12 including the insertion tube portion 13, the spiral portion 14, and the grip portion 15 is a material to which spatter scattered during welding is less likely to adhere than the material of the nozzle 4. For example, when the material of the nozzle 4 of the welding torch 1 is carbon steel, the material of the nozzle attachment 12 is stainless steel with an insulating coating (KCF), silicone rubber, resin (heat-resistant resin), ceramic, or the like. By attaching the nozzle attachment 12 made of these materials to the nozzle 4 of the welding torch 1, spatter is less likely to adhere to and accumulate on the nozzle attachment 12 than on the nozzle 4 before attachment, and the life of the nozzle attachment 12 is extended.

[0036] Although the preferred embodiment of the present invention has been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to the above-mentioned embodiment, and various modifications or alterations within the scope of the claims also fall within the technical scope of the present invention. For example, in FIG. 3, the helical pitch in the longitudinal direction of the helical portion 14 may be the same (P1=P2). In addition, the height of the crests in the longitudinal direction of the helical portion 14 may all be the same, and the inner diameter at the top of each crest may be constant (D1=D2). [Industrial Applicability]

[0037] The present invention relates to a nozzle attachment that is attached and detached to the nozzle of a welding torch, and in particular can be used as a nozzle attachment for a welding torch that can efficiently reduce the consumption of shielding gas sprayed from the nozzle toward the welding point of the workpiece. [Explanation of symbols]

[0038] 1. Welding torch 2. Welding wire 3. Chip 4 Nozzles 5 aperture 6. Welded parts 7 Welding points 8 Bevel 9. Arc 12 Nozzle attachment 13 Insertion tube 14 Spiral section 15 Gripping part 15a Flange part 15b Outer cylinder part P1 Spiral pitch P2 Spiral pitch D1 Inner diameter D2 Inner diameter G Shielding gas

Claims

1. A nozzle attachment is attached to and detached from the nozzle of a welding torch that is equipped with a rod-shaped tip that feeds out a welding wire from its front end and a cylindrical nozzle that surrounds the tip, and that performs arc welding by ejecting a shielding gas flowing between the nozzle and the tip from an opening of the nozzle to a welding point, A nozzle attachment for a welding torch, characterized in having a cylindrical insertion tube portion that is removably inserted from an opening of the nozzle so as to contact the inner surface of the nozzle, and a spiral portion formed in a spiral shape on the inner surface of the insertion tube portion to impart a swirling flow to the shielding gas flowing between the insertion tube portion and the tip.

2. 2. The nozzle attachment for a welding torch as described in claim 1, wherein the spiral portion is formed so that the spiral pitch narrows from the upstream side to the downstream side of the shielding gas flowing between the insertion tube portion and the tip.

3. 3. The nozzle attachment for a welding torch as described in claim 1 or 2, characterized in that the spiral portion is formed such that the height of the peaks constituting the spiral portion increases from the upstream side to the downstream side of the shielding gas flowing between the insertion tube portion and the tip, and the inner diameter of the insertion tube portion at the top of the peaks gradually decreases.

4. 3. A nozzle attachment for a welding torch as described in claim 1 or 2, characterized in that a gripping portion is provided at the tip of the insertion tube portion to be gripped by the fingers of an operator when inserting the insertion tube portion into the opening of the nozzle of the welding torch, and the gripping portion has a flange portion extending radially outward from the tip of the insertion tube portion and an outer tube portion extending in the axial direction of the insertion tube portion from the outer edge of the flange portion so as to contact the outer peripheral surface of the nozzle.

5. 5. A nozzle attachment for a welding torch as described in claim 4, characterized in that the materials of the insertion tube portion, the spiral portion and the gripping portion are less susceptible to spatter that flies off during welding than the material of the nozzle.

6. 6. The nozzle attachment for a welding torch according to claim 5, wherein the material of the insertion tube portion, the spiral portion and the grip portion is stainless steel with an insulating coating, silicone rubber, resin or ceramic.

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