attachment

Abstract

To provide a new shield gas jetting device which can withstand a realistic packaging and is installed around a spot welding electrode.SOLUTION: An attachment for a spot welding electrode includes: an outer peripheral wall, an inner peripheral wall, and an upper wall forming a cylindrical body; and a flow straightening part provided between the outer peripheral wall and the inner peripheral wall. The outer peripheral wall is provided with a shield gas supply part which supplies a shield gas to the flow straightening part. The flow straightening part includes a flow straightening structure which straightens flow of the shield gas supplied from the shield gas supply part to cause the shield gas to flow to a lower part. At least the outer peripheral wall, the inner peripheral wall, and the flow straightening part are formed of the same material. The flow straightening part includes an integral component which is continuous with at least the outer peripheral wall or the inner peripheral wall.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an attachment for ejecting shielding gas that is installed around a spot welding electrode. [Background technology]

[0002] Spot welding is a type of resistance welding in which two workpieces are typically welded together by applying pressure with a rod-shaped electrode while passing a large current through them, melting the workpieces with resistance heat. The molten part is called a nugget, and the electrode rod is usually cooled with cooling water. Spot welding is advantageous in places where the weld area is small and space is limited, and is frequently used in automobile frames, etc. Furthermore, because it produces a beautiful finish, it is often used when appearance is important.

[0003] Electrodes used for spot welding are sometimes called tips or cap tips, and basically have a rod-shaped or cylindrical body with a tip that can be flat, domed, radiused, or a combination of these or offset, depending on the application.

[0004] Spot welding offers many benefits. However, one of the challenges is the discoloration that often remains around the dent, often referred to as "burn." This "burn" is caused by oxidation of the heat-affected zone during welding. For example, when the workpiece is stainless steel, this "burn" adversely affects corrosion resistance, making it preferable to remove it. Furthermore, this type of burn treatment is often required for welds where aesthetics are important. Therefore, these "burn" removal processes require considerable effort, time, and expense. Specific treatment methods include chemical treatments using nitric hydrofluoric acid or a mixture of hydrochloric and nitric acid, electrolysis using an electrolyte, and mechanical methods using cutting. However, these methods not only require removal but also require separate equipment and procedures for material management and post-processing, which places a burden not only on time but also on human resources, space, and costs.

[0005] In response to this situation, it has been proposed to provide a shielding gas injection device for spot welding in order to prevent the occurrence of burns (Patent Document 1, Patent Document 2). These shielding gas injection devices prevent oxidation and, in turn, discoloration of the welding point by filling the area around the electrode with a shielding gas such as argon gas.

[0006] However, despite the disclosure of these technologies, unlike arc welding, shielding gas injection devices are rarely implemented in general, and the reality is that the above process is still carried out with much effort, time, and expense. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-197977 [Patent Document 2] Japanese Patent Application Laid-Open No. 2009-107000 Summary of the Invention [Problem to be solved by the invention]

[0008] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a new shielding gas ejection device that can withstand practical implementation and is installed around a spot welding electrode. [Means for solving the problem]

[0009] In order to solve the above problems, the attachment for a spot welding electrode of the present invention comprises an outer peripheral wall, an inner peripheral wall, and an upper wall that form a cylindrical body, and a rectifying section that is provided between the outer peripheral wall and the inner peripheral wall, the outer peripheral wall is provided with a shielding gas supply section to the rectifying section, the rectifying section has a rectifying structure that rectifies the shielding gas supplied from the shielding gas supply section and causes it to flow downward, at least the outer peripheral wall, the inner peripheral wall, and the rectifying section are made of the same material, and the rectifying section has an integral component that is continuous with at least the outer peripheral wall or the inner peripheral wall.

[0010] Furthermore, the present invention provides an attachment for a spot welding electrode, the attachment having an outer peripheral wall, an inner peripheral wall, and an upper wall constituting a cylindrical body, a space portion provided at the upper part between the outer peripheral wall, the inner peripheral wall, and the upper wall, a rectifying portion provided at the lower part, a shielding gas supply portion provided on the outer peripheral wall or the upper wall for supplying shielding gas to the space portion, the rectifying portion having a rectifying structure for rectifying the shielding gas supplied from the shielding gas supply portion through the space portion and causing it to flow to the lower part, at least the outer peripheral wall, the inner peripheral wall, and the rectifying portion being made of the same material, and the rectifying portion having an integral structure continuous with at least the outer peripheral wall or the inner peripheral wall. It is also preferable that only one shielding gas supply portion is provided. It is also preferable that the attachment has an obliquely cut cylindrical shape, and that the shielding gas supply portion is provided at the top.

[0011] Furthermore, the present invention is an attachment to be placed around a rod-shaped electrode for resistance welding, comprising an outer peripheral wall and an inner peripheral wall that form a cylindrical body, and a rectifying section provided between the outer peripheral wall and the inner peripheral wall, wherein a shielding gas supply section is provided on the outer peripheral wall, the inner wall does not have a protrusion facing toward the inner space, and the rectifying section has a rectifying structure that rectifies the shielding gas supplied from the shielding gas supply section and flows it downward, and the outer peripheral wall, inner peripheral wall, shielding gas supply section, and rectifying section are made of the same material, and the entire attachment is formed as a single unit.

[0012] It is also preferable that the outer peripheral wall has no protrusions facing outward other than the shielding gas supply portion, and that the inner peripheral wall has no protrusions facing toward the inner space. It is also preferable that the housing has an opening extending from the outer peripheral wall to the inner peripheral wall for inserting a fixing member.

[0013] After careful consideration, the inventors of the present invention have concluded that the requirements for space, mobility, burn removal, ease of work, efficiency, and cost must all be simultaneously satisfied, as these are obstacles to the implementation of conventional technologies. In particular, the requirements for space and mobility in spot welding are extremely important, as they are closely related to the very reason why spot welding is chosen. At the same time, burn removal is also important, and insufficient removal ultimately results in the need for reprocessing. Furthermore, unless ease of work, efficiency, and cost are satisfied, on-site implementation is difficult. In light of these issues and further consideration, the present invention was completed.

[0014] The present invention is configured as an attachment to be attached around an electrode, and includes an outer peripheral wall and an inner peripheral wall that form a cylindrical body, and a flow straightening unit provided between the outer peripheral wall and the inner peripheral wall. The attachment has an overall cylindrical / columnar shape, and the internal space formed by the outer peripheral wall and the inner peripheral wall serves as a shielding gas flow path. Therefore, the upper part is blocked by an upper wall or the like to prevent the shielding gas from escaping, and a shielding gas supply unit is provided on the outer peripheral wall or the upper wall. Typically and preferably, the shielding gas supply unit is a nozzle integral with the body, which receives the shielding gas and supplies it to the internal space formed by the outer peripheral wall and the inner peripheral wall. The shielding gas supply unit is not limited to a nozzle shape, and may be configured as an opening in the outer peripheral wall, with other forms, such as inserting a separate pipe or the like into the opening, are not excluded. To minimize the impact on the space and mobility of the spot welding device, the shielding gas supply unit is preferably provided on the upper part of the attachment, specifically, at the top or above the longitudinal center of the outer peripheral wall.

[0015] The outer peripheral wall preferably has no protruding parts facing outward other than the shielding gas supply part. This configuration is important for ensuring space and mobility while also ensuring ease of attachment and detachment and versatility. The inner peripheral wall is also configured without any protruding parts facing the internal space, similarly ensuring space and mobility while also ensuring ease of attachment and detachment, avoiding contact with the electrode, and ensuring quality.

[0016] Furthermore, an opening for inserting a fixing member is provided, penetrating from the outer peripheral wall to the inner peripheral wall, making it possible to fix the attachment to the electrode. While known members and means can be used to fix the attachment without any particular limitations, it is preferable to use a member that can be fixed by inserting it into the opening, such as a screw. This configuration, which allows for fixation by simply inserting it into the opening, further improves ease of operation, efficiency, and cost-effectiveness, while minimizing restrictions on space and mobility. It is preferable that the periphery of the opening in the rectifying section be constructed with a sealed wall to prevent gas leakage.

[0017] The flow straightening section straightens the gas supplied from the shielding gas supply section, providing a longer laminar flow from the bottom. While any known flow straightening configuration can be used for this purpose, manufacturing it integrally with the outer and / or inner peripheral walls can achieve a higher shielding effect without waste. It has been found that not only a configuration with a regular three-dimensional lattice cross section, but also an irregular porous configuration, can produce good welding results. However, when using an irregular porous configuration, it is necessary to pay attention to the design to ensure communication so that the gas from the supply section can be discharged from the bottom.

[0018] In the present invention, it is optimal that the outer peripheral wall, inner peripheral wall, and straightening portion are made of the same material and are integrally constructed. Furthermore, to achieve the most suitable straightening configuration in the present invention, it is preferable to manufacture using a 3D printer. This configuration maximizes miniaturization and minimizes restrictions on space and mobility. It also ensures freedom in the shape of the straightening portion, enabling more suitable laminar flow to be achieved.

[0019] In the present invention, the preferred diameter is determined by the electrode diameter, and therefore is not limited to a specific diameter. However, if the outer diameter is configured to be 30 mm or less, particularly 24 mm or less, and the thickness of the outer and inner peripheral walls is 1 mm or less, particularly 0.5 mm or less, and the thickness of the rectifying portion is 5 mm, particularly 3 mm or less, it is possible to accommodate most electrodes and obtain a high shielding effect while minimizing restrictions on the space and mobility of the welding equipment.

[0020] A plurality of shielding gas supply units can be provided to the flow straightening unit. Preferably, they are formed in a nozzle shape, and the nozzle preferably consists of a first pipe portion facing outward and a second pipe portion facing upward, maintaining space and movability while avoiding the welding equipment. To equalize the gas supply, two supply units are preferably provided at 180 degrees from each other, and three supply units are preferably provided at equal distances from each other, such as 120 degrees from each other.

[0021] In another embodiment, a configuration with a single shielding gas supply unit can be provided. In this case, a space is provided above the rectifying unit to ensure optimal homogenization of the gas supply to the rectifying unit. Furthermore, the attachment can be formed in an obliquely cut cylindrical shape, with the space at its top and the rectifying unit at its bottom, and the shielding gas supply unit provided at the top. In other words, the longitudinal length of the attachment is configured to be greatest at the position of the shielding gas supply unit. A guide flow path may be provided within the space. This configuration is effective for ensuring a flow path, homogenizing the gas supply to the rectifying unit, and miniaturization. The present invention can be adopted in various welding machines that perform resistance welding using spot welding electrodes, such as portable spot welding devices and single-sided spot welding devices, and can be used with any of the lower, upper, and single-sided electrodes.

[0022] The material of the attachment can be any material that can be shaped using a 3D printer, including, but not limited to, steels such as iron and stainless steel, titanium, copper, etc. However, for the purpose of shielding gas ejection, materials with high thermal conductivity, heat resistance, corrosion resistance, and hardness are preferred. For this reason, copper or copper alloys such as chromium copper are suitable, similar to the materials used for welding electrodes.

[0023] In use, the attachment is attached to the electrode and the shielding gas pipe is connected to the shielding gas supply. In this invention, there are no unnecessary protrusions on the outer or inner circumference, and the attachment can be easily attached to and detached from the electrode through the fixing opening. Spot welding is then performed under a spray of shielding gas. This process prevents burns and ensures good welding. [Effects of the Invention]

[0024] The attachment of the present invention maintains space and movable area while being easy to remove, easy to work with, efficient, and cost-effective, and can withstand practical implementation. [Brief explanation of the drawings]

[0025] [Figure 1] FIG. 1 is a perspective view showing an example of an attachment of the present invention. [Figure 2] FIG. 2 is a front view of the attachment of FIG. 1. [Figure 3] FIG. 2 is a plan view of the attachment of FIG. 1. [Figure 4] FIG. 2 is a bottom view of the attachment of FIG. 1. [Figure 5] FIG. 2 is a cross-sectional view of the attachment of FIG. 1. [Figure 6] FIG. 10 is a perspective view showing another example of the attachment of the present invention. [Figure 7] FIG. 7 is a front view of the attachment of FIG. 6. [Figure 8] FIG. 7 is a plan view of the attachment of FIG. 6. [Figure 9] FIG. 7 is a bottom view of the attachment of FIG. 6. [Figure 10] FIG. 7 is a perspective view showing the inside of the attachment of FIG. 6. [Figure 11] FIG. 2 is a perspective view showing a flow control part of the attachment of FIG. 1. [Figure 12] FIG. 7 is a perspective view showing a flow regulating portion of the attachment of FIG. 6. [Figure 13] 2 is a diagram showing a state in which the attachment of FIG. 1 is installed on a spot welding device. FIG. [Figure 14]FIG. 10 is a comparative diagram showing welding results. [Figure 15] FIG. 10 is a comparative diagram showing welding results. DETAILED DESCRIPTION OF THE INVENTION

[0026] An embodiment of the present invention will be described with reference to the drawings. [Example]

[0027] 1 to 5 are a perspective view, a front view, a plan view and a bottom view showing an example of an attachment of the present invention.

[0028] The attachment 1 shown in Figure 1 is integrally formed entirely from a copper alloy and is configured in a cylindrical, columnar shape, including an outer peripheral wall 2, an inner peripheral wall 3, an upper wall 4, and a flow straightening section 5 provided between the outer peripheral wall 2 and the inner peripheral wall 3. Nozzles 6 and 7 are provided on the outer peripheral wall 2. The outer diameter of the attachment 1 is 18 mm, the inner diameter of the inner wall is 12 mm, the outer peripheral wall 2 is 0.5 mm thick, and the inner peripheral wall 3 is 0.5 mm thick. The length excluding the nozzles 6 and 7 is 21.5 mm, and the outer peripheral wall 2 has no outwardly protruding portions, while the inner peripheral wall 3 has no inwardly protruding portions.

[0029] The nozzles 6 and 7 are provided 14.5 mm from the bottom end, and each has a first portion 8 facing outward and a second portion 9 parallel to the axis 10 of the attachment 1, ensuring space and movability when installed. In addition, the nozzles 6 and 7 are provided at positions 180 degrees apart on the outer peripheral wall 2, ensuring movability and the introduction of uniform gas into the flow straightening section 5.

[0030] The flow straightening section 5 has an irregular porous structure (Fig. 11) overall, but the voids are ultimately connected to the lower part. In addition, the flow straightening section 4 is formed integrally with the outer peripheral wall 2, inner peripheral wall 3, and upper wall 4, which makes it possible to provide laminar flow to the lower part without generating non-flow straightening areas and without waste, with a minimum volume.

[0031] An opening 11 is provided in the outer peripheral wall of the attachment 1. The attachment can be attached by fastening it to the electrode with a screw via the opening 11. The opening 11 penetrates from the outer peripheral wall 2 to the inner peripheral wall 3, and the area around the penetration is made up of a sealed wall and has a screw receiving groove, ensuring ease of attachment and detachment and preventing unexpected gas leakage.

[0032] FIG. 13 is a photograph showing the attachment 1 according to this embodiment used in a spot welding machine. The attachment 1 is installed around the upper electrode of the spot welding machine. The attachment 1 is fixed to the periphery of the electrode with screws 13 provided in openings 11. The attachment 1 is installed so that shielding gas can be supplied to the nozzles 6 and 7 from an argon gas tank via hose 14. Removal can be easily achieved by simply removing the hose 14 from the nozzles 6 and 7 and then removing the screws 12. [Example]

[0033] 6 to 10 are perspective views, front views, plan views, bottom views, and perspective views showing another example of the attachment of the present invention. Since the main configuration is the same as in Example 1, the same reference numerals are used to distinguish between them with "'" and differences will be mainly described.

[0034] The attachment 1' comprises an outer peripheral wall 2', an inner peripheral wall 3', and an upper wall 4', and is configured as an obliquely cut cylinder overall. The outer peripheral wall 2', inner peripheral wall 3', and upper wall 4' define an internal space, which includes a space 12 at the top and a flow straightening section 5' at the bottom. A nozzle 6' is located at the top. The attachment 1' has an outer diameter of 22 mm, an inner diameter of 16 mm, a thickness of the outer peripheral wall 2' of 0.5 mm, and a thickness of the inner peripheral wall 3' of 0.5 mm. The outer peripheral wall 2' has no outward convexities, and the inner peripheral wall 3' has no inward convexities. The space 12 gradually widens from the gas inlet of the nozzle 6 toward the flow straightening section 5', ensuring uniform gas supply to the flow straightening section 5'. Furthermore, the single nozzle 6' provides a unique design while also providing advantageous space-saving and maneuverability for the welding machine. The length of the attachment at the nozzle supply portion is 47.8 mm, and the length at the shortest portion at the 180 degree separation position is 20.8 mm.

[0035] The cross section of the flow straightening section 5' has a regular lattice structure, and the flow straightening section 5' is connected to the lower part as a whole with a different phase. In addition, the flow straightening section 5' is formed integrally with the outer peripheral wall 2', inner peripheral wall 3', and upper wall 4', which makes it possible to provide a laminar flow to the lower part efficiently with a minimum volume and without generating non-rectified gas portions.

[0036] The results of normal welding (comparative example) without the attachment of the present invention and welding with the attachments described in Examples 1 and 2 are shown in Figures 14 and 15, respectively. In these examples, SUS304 was used as the workpiece, and a spot welder manufactured by ARO was used. The welding conditions were current: 6000 A (DC inverter), welding time: 600 sec (30 Hz), and pressure: 200 daN, and all conditions were the same except for the presence or absence of an attachment and argon shielding gas.

[0037] In both the comparative examples shown in Figures 14 and 15, obvious discoloration can be seen around the dents. In contrast, there is no discoloration in either the welding performed with the attachments of Examples 1 and 2, and the quality is such that no post-processing is required. Therefore, according to the present invention, an efficient burn prevention means is provided that simultaneously satisfies the requirements of space, movable area, burn removal, ease of work, efficiency, and cost. [Explanation of symbols]

[0038] 1 Attachment 2 Outer wall 3 Inner wall 4 Upper wall 5 Rectifier 6 nozzles 7 nozzles 8. First Part 9 Second Part 10 axes 11 Aperture 12 Space 13 screws 14 Hose

Claims

1. An attachment for a spot welding electrode, The device includes an outer peripheral wall, an inner peripheral wall, and an upper wall that form a cylindrical body, and a flow straightening section that is provided between the outer peripheral wall and the inner peripheral wall, A shielding gas supply section to the flow straightening section is provided on the outer peripheral wall, the rectifying unit has a rectifying configuration that rectifies the shielding gas supplied from the shielding gas supply unit and causes it to flow in a direction parallel to the axis of the electrode; At least the outer peripheral wall, inner peripheral wall, and flow straightening section are made of the same material, An attachment for ejecting shielding gas, wherein the flow straightening portion has an integral component portion that is continuous with at least the outer peripheral wall or the inner peripheral wall.

2. 2. The attachment according to claim 1, wherein the shielding gas supply section comprises a plurality of nozzles provided on the outer peripheral wall.

3. An attachment for a spot welding electrode, The cylindrical body has an outer peripheral wall, an inner peripheral wall, and an upper wall, A space is provided at the top of the space surrounded by the outer peripheral wall, the inner peripheral wall, and the upper wall, and a flow straightening section is provided at the bottom. a shielding gas supply unit for supplying a shielding gas to the space is provided on the outer peripheral wall or the upper wall; the rectifying unit has a rectifying configuration that rectifies the shielding gas supplied from the shielding gas supply unit through the space and causes the shielding gas to flow in a direction parallel to the axis of the electrode; At least the outer peripheral wall, inner peripheral wall, and flow straightening part are made of the same material, An attachment for ejecting shielding gas, wherein the flow straightening portion has an integral structure that is continuous with at least the outer peripheral wall or the inner peripheral wall.

4. 4. The attachment according to claim 3, wherein only one shielding gas supply section is provided.

5. 5. The attachment according to claim 4, wherein the attachment is in the shape of an obliquely cut cylinder, and the shielding gas supply section is provided at the top.

6. 6. The attachment according to claim 1, wherein the outer peripheral wall has no outwardly directed protrusions other than the shielding gas supply portion.

7. 7. The attachment according to claim 1, wherein the inner peripheral wall has no protrusions facing the inner space.

8. An attachment to be installed around a rod-shaped electrode for resistance welding, The cylindrical body includes an outer peripheral wall and an inner peripheral wall, and a flow straightening portion provided between the outer peripheral wall and the inner peripheral wall, A shielding gas supply unit is provided on the outer peripheral wall, The inner wall does not have a protrusion toward the inner space, the rectifying unit has a rectifying configuration that rectifies the shielding gas supplied from the shielding gas supply unit and causes it to flow in a direction parallel to the axis of the electrode; An attachment for ejecting shielding gas, in which the outer and inner walls, shielding gas supply section, and flow rectification section are all made of the same material and are integrally formed.

9. 9. The attachment according to claim 8, wherein the outer peripheral wall has no outwardly projecting portion other than the shielding gas supply portion.

10. 10. The attachment according to claim 1, wherein the outer diameter is 30 mm or less.

11. 11. The attachment according to claim 1, wherein the thickness of the airflow regulating portion is 5 mm or less.

12. 12. An attachment according to claim 1, wherein the thickness of the outer peripheral wall and the inner peripheral wall is 1 mm or less.

13. 13. The attachment according to claim 1, further comprising an opening extending from the outer peripheral wall to the inner peripheral wall for inserting a fixing member.

14. A welding device comprising the attachment according to any one of claims 1 to 12.

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