Welding equipment

Abstract

To provide a welding apparatus capable of stably supplying cooled shielding gas. [Solution] The welding apparatus 1 comprises a welding torch 40 and a gas supply device 15 that supplies shielding gas to the welding torch 40. The gas supply device 15 includes a thermoelectric element 23 and a gas cooling passage 22 through which the shielding gas passes and which is cooled by the thermoelectric element 23. The welding torch 40 is a water-cooled torch with a water channel for cooling water. The gas supply device 15 is configured such that the high-temperature side of the thermoelectric element 23 dissipates heat to the cooling water, and the low-temperature side of the thermoelectric element 23 absorbs heat from the gas cooling passage 22.

Description

Technical Field

[0001] The present disclosure relates to a welding apparatus using shielding gas.

Background Art

[0002] Japanese Patent Application Laid-Open No. 2-155573 discloses a welding method in which shielding gas supplied to a welding torch is pre-cooled by a cooling device, a power cable for supplying power to an electrode of the welding torch is cooled by the cooled shielding gas, and the cooled shielding gas is ejected from the welding torch.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the welding method disclosed in Japanese Patent Application Laid-Open No. 2-155573, pre-cooled shielding gas is used to cool the power cable. However, there are other advantages to cooling the shielding gas.

[0005] The first advantage is the improvement of shielding performance. Normally, in a normal state, the gas flow is a laminar flow that is stable up to a certain distance from the nozzle, and the flow beyond that is a turbulent flow. If an arc is generated in the space where the shielding gas is in a laminar flow state, the mixing of outside air can be reduced and the generation of blowholes due to the mixing of outside air can be prevented. However, if the flow rate is increased to ensure the shielding width or the flow velocity is increased to resist wind, there is a concern that turbulent flow will become dominant and air will be entrained. Therefore, by cooling the shielding gas supplied to the welding torch, the density of the gas increases, the shielding performance during welding can be enhanced, and the entrainment of the gas can be prevented.

[0006] The second advantage is the ability to cool the workpiece and the weld bead during multi-pass welding. For example, in processes where long welding times are expected, such as WAAM (Wire-Arc Additive Manufacturing), heat sagging during bead stacking significantly impacts the quality of the laminate. Cooling the shielding gas can prevent bead sagging.

[0007] However, in the welding method disclosed in Japanese Patent Publication No. 2-155573, the shielding gas is cooled using cooling water from a tap after the power cable has been cooled, making it difficult to cool it sufficiently. Furthermore, although many water-cooled welding torches exist, their structures are designed to cool the welding torch body itself, and their cooling capacity depends on the water temperature and flow rate, and is not sufficient to efficiently cool the gas. Therefore, the welding equipment used in these devices cannot cool the shielding gas to a constant temperature, and there is room for improvement.

[0008] This disclosure aims to solve these problems and to provide a welding apparatus capable of stably supplying cooled shielding gas. [Means for solving the problem]

[0009] This disclosure relates to a welding apparatus. The welding apparatus comprises a welding torch and a gas supply device that supplies shielding gas to the welding torch, the gas supply device including a thermoelectric element and a gas cooling passage configured for the passage of the shielding gas and cooled by the thermoelectric element. [Effects of the Invention]

[0010] According to the welding apparatus of this disclosure, a stably cooled shielding gas can be used, thereby improving welding quality. [Brief explanation of the drawing]

[0011] [Figure 1] This is a block diagram showing the configuration of the welding apparatus according to Embodiment 1. [Figure 2]This is a perspective view showing the external appearance of the thermoelectric element cooling unit. [Figure 3] This is a perspective cross-sectional view showing the internal structure of a thermoelectric element cooling unit. [Figure 4] This diagram shows the flow of gas and cooling water in a thermoelectric element cooling unit. [Figure 5] This is a cross-sectional view showing the structure of the welding torch (MIG, single shielded gas) used in Embodiment 1. [Figure 6] This is a cross-sectional view showing the structure of a welding torch (TIG, single shielded gas) used in a modified example of Embodiment 1. [Figure 7] This figure shows the density of the gas emitted from the torch when shielding gas at normal temperature is supplied. [Figure 8] This figure shows the density of the gas emitted from the torch when cooled shielding gas is supplied. [Figure 9] This diagram shows the configuration of welding apparatus 1A, a modified example of Embodiment 1. [Figure 10] This is a block diagram showing the configuration of the welding apparatus according to Embodiment 2. [Figure 11] This is a cross-sectional view showing the structure of the welding torch (MIG, double-shielded gas) used in Embodiment 2. [Figure 12] This is a cross-sectional view showing the structure of a welding torch (TIG, double-shielded gas) used in a modified example of Embodiment 2. [Figure 13] Figure 12 shows the flow of shielding gas and cooling water in a welding torch (TIG, double shielding gas). [Figure 14] This is an illustrative diagram showing the turbulent state of the gas emitted from the torch when a normal double-shielded gas is supplied. [Figure 15] This is an illustrative diagram showing the turbulent state of the gas emitted from the torch when cooled outer gas is supplied. [Modes for carrying out the invention]

[0012] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Hereinafter, embodiments including a plurality of modification examples will be described, but it is planned from the beginning of the application to appropriately combine the configurations described in each embodiment. In the drawings, the same or corresponding parts are denoted by the same reference numerals and their descriptions will not be repeated.

[0013] [Embodiment 1] FIG. 1 is a block diagram showing the configuration of a welding apparatus according to Embodiment 1. The welding apparatus 1 shown in FIG. 1 includes a welding torch 40 and a gas supply device 15. The gas supply device 15 supplies shielding gas to the welding torch 40. The gas supply device 15 includes a thermoelectric element cooling unit 20 and a solenoid valve 30. The thermoelectric element cooling unit 20 includes a thermoelectric element 23, a cooling water passage 21, and a gas cooling passage 22. The shielding gas is supplied from a gas supply source 10 (e.g., a gas cylinder, etc.) to the welding torch 40 via the gas hoses 51, 52, 53, the gas cooling passage 22, and the solenoid valve 30.

[0014] The welding torch 40 is a water-cooled torch having a water passage for cooling water. The welding apparatus 1 further includes circulation water passages 61, 62, 63 for circulating the cooling water. The circulation water passages 61, 62, 63 are configured such that the cooling water flows from a cooling water supply source 50 to the welding torch 40 and the gas supply device 15 in this order, and then returns to the cooling water supply source 50. By doing so, the cooling water is effectively utilized.

[0015] ] FIG. 2 is a perspective view showing the appearance of the thermoelectric element cooling unit. FIG. 3 is a perspective cross-sectional view showing the internal structure of the thermoelectric element cooling unit. FIG. 4 is a diagram showing the flow of gas and cooling water in the thermoelectric element cooling unit.

[0016] Thermoelectric element modules work by transferring heat when electricity is applied. Electrons move in one element, while holes move in the other. This effect is called the "Peltier effect." Thermoelectric element modules are devices capable of changing surface temperature and maintaining a target temperature (temperature control). They have a wide operating temperature range of approximately -30°C to 120°C, allowing for both cooling and heating. They are relatively small and easy to apply to various uses. For example, Peltier elements, a type of thermoelectric element, are mainly used in computer CPU coolers and dedicated refrigerators.

[0017] As shown in Figures 2 and 4, the thermoelectric element 23 is sandwiched between a gas cooling passage 22 and a cooling water passage 21. The gas cooling passage 22 is in contact with the low-temperature side of the thermoelectric element 23 and is cooled by the thermoelectric element 23. Port P1 of the gas cooling passage 22 is connected to a gas hose 51, and port P2 of the gas cooling passage 22 is connected to a gas hose 52. The gas cooling passage 22 is configured so that shielding gas passes from port P1 to port P2, and the shielding gas is cooled as it passes through the gas cooling passage 22.

[0018] On the other hand, the cooling water passage 21 is in contact with the high-temperature side of the thermoelectric element 23 and absorbs heat from the thermoelectric element 23. Port P3 of the cooling water passage 21 is connected to the circulation water passage 61, and port P4 of the cooling water passage 21 is connected to the circulation water passage 62. The cooling water passage 21 is configured so that cooling water passes from port P3 to port P4, and the cooling water absorbs heat as it passes through the cooling water passage 21. In other words, the cooling water passage 21 is cooled by the cooling water.

[0019] The jackets connected to the thermoelectric element 23, namely the cooling water passage 21 and the gas cooling passage 22, are preferably made of copper or a copper alloy, which has high thermal conductivity, on both the heat absorption and heat dissipation sides. The heat absorption and heat dissipation side jackets are in the shape of a heat sink block through which a fluid or gas passes. Shielding gas passes through the heat absorption side, and cooling water passes through the heat dissipation side to promote cooling. While dedicated cooling water for the gas may be used, if a water-cooled torch is used, the gas can be cooled using the same cooling water used for the torch, as shown in Figure 1.

[0020] By controlling the temperature on the heat absorption side, the jacket is cooled, and the temperature of the shielding gas decreases as it passes through the cooled pipes inside the jacket. Then, the cooled and denser shielding gas is supplied to the welding torch 40.

[0021] In Figure 1, the thermoelectric element cooling unit is placed between the gas supply source 10 and the solenoid valve 30, but it may also be placed between the solenoid valve 30 and the welding torch 40. Since the gas solenoid valve can handle fluids from -20 to 50°C, the fluid may be allowed to pass through the solenoid valve 30 after being cooled.

[0022] Figure 5 is a cross-sectional view showing the structure of a welding torch (MIG, single-shielded gas) used in Embodiment 1. The welding torch 40A shown in Figure 5 includes a liner 111 that guides the welding wire, a contact tip 170 positioned at the tip of the liner 111 to supply power to the welding wire, and a cylindrical gas nozzle 150 positioned to surround the contact tip 170.

[0023] The gas nozzle 150 includes an outer member 152, an inner member 151, and a tip member 153. A cooling water passage 191 is provided between the outer member 152 and the inner member 151, and cooling water is supplied from a cooling water hose 190.

[0024] The contact tip 170 is attached to the tip of the tip body 100, 101. The support member 180 is positioned to secure a gap between the gas nozzle 150 and the tip body 101, and although not shown, it is provided with a groove for gas to pass through. The gap between the gas nozzle 150 and the tip body 101 is a gas passage 181 through which the shielding gas passes.

[0025] Figure 6 is a cross-sectional view showing the structure of a welding torch (TIG, single shielded gas) used in a modified example of Embodiment 1.

[0026] The welding torch 40B shown in Figure 6 includes a welding electrode 270 made of tungsten or the like, and a cylindrical gas nozzle 250 arranged to surround the welding electrode 270.

[0027] The welding electrode 270 is inserted into the collets 200 and 202. The collets 200 and 202 are supported by collet bodies 280 and 201, respectively.

[0028] The gas nozzle 250 is attached to the outer member 283 and the tip of the inner member 282. A cooling water passage 291 is provided between the outer member 283 and the inner member 282, and cooling water is supplied from a cooling water hose.

[0029] A gas passage 281 is provided in the gap on the inside of the inner member 282 on the outside of the collet body 201 for supplying shielding gas to the gas nozzle 250.

[0030] Figure 7 shows the density of gas emitted from the torch when shielding gas at normal temperature is supplied. Figure 8 shows the density of gas emitted from the torch when cooled shielding gas is supplied.

[0031] Comparing Figures 7 and 8, it can be seen that when cooled shielding gas is supplied, the density of the shielding gas emitted from the torch tip is higher than when normal gas is supplied. This prevents gas turbulence and improves shielding performance during welding.

[0032] Figure 9 shows the configuration of a modified welding apparatus 1A of Embodiment 1. In the configuration of welding apparatus 1 shown in Figure 1, welding apparatus 1A is equipped with circulating water channels 65, 66, 67, and 68 instead of circulating water channels 61, 62, and 63 for circulating cooling water. In Figure 1, cooling water is flowed to the thermoelectric element cooling unit 20 after passing through the welding torch 40, but as shown in Figure 9, the circulating water channels 65, 66, 67, and 68 may be configured so that the cooling water flows in parallel to the welding torch 40 and the high-temperature side of the thermoelectric element 23. In this case, the water channels become more complex, but the temperature of the cooling water that cools the thermoelectric element will be lower than in Figure 1, which is effective when it is desired to lower the temperature of the shielding gas even further.

[0033] In this case as well, the welding torches shown in Figures 7 and 8 can be used. According to the welding apparatus of Embodiment 1, a stably cooled shielding gas can be used, thereby improving welding quality.

[0034] [Embodiment 2] Embodiment 1 described a welding apparatus using a single shielding gas. Embodiment 2 describes a welding apparatus using a double shielding gas.

[0035] Figure 10 is a block diagram showing the configuration of the welding apparatus according to Embodiment 2. The welding apparatus 301 shown in Figure 10 comprises a welding torch 340 and a gas supply device 15A. The gas supply device 15A supplies two types of shielding gas, inner gas and outer gas, to the welding torch 340. The gas supply device 15A includes a thermoelectric element cooling unit 20, flow divider valves 353 and 358, an inner gas switching valve SW1, and an outer gas switching valve SW2.

[0036] The thermoelectric element cooling unit 20 has the same configuration as described in Figures 2-4, so we will not repeat the explanation here.

[0037] The welding torch 340 is a water-cooled torch having a cooling water channel. The welding apparatus 301 further includes circulation channels 61, 62, and 63 for circulating the cooling water. The circulation channels 61, 62, and 63 are configured so that the cooling water flows from the cooling water supply source 50 to the welding torch 340, then to the gas supply device 15, and then returns to the cooling water supply source 50.

[0038] The shielding gas is distributed from the gas supply source 10 (for example, a gas cylinder) through gas hoses 351 and 352, then through a flow divider valve 353, and finally to gas hoses 354 and 356. This path is the flow path for the gas cooled by the thermoelectric element cooling unit 20.

[0039] Furthermore, the shielding gas is diverted from the gas supply source 110 (for example, a gas cylinder) through the gas hose 357, then through the flow divider valve 358, and finally to the gas hoses 359 and 361. This path is the flow path for gas that is not cooled by the thermoelectric element cooling unit 20. Hereafter, the shielding gas that is not cooled by the thermoelectric element cooling unit 20 will be referred to as "room temperature gas," and the shielding gas that has been cooled by the thermoelectric element cooling unit 20 will be referred to as "cooled gas." Alternatively, instead of providing the gas supply source 110, the shielding gas may be supplied from the gas supply source 10 to the gas hose 357 via the flow divider valve.

[0040] The inner gas switching valve SW1 includes solenoid valves 333 and 334. Solenoid valve 333 is located between gas hose 354 and gas hose 355 and switches whether or not cooled gas is sent to gas hose 364 for the inner gas. Solenoid valve 334 is located between gas hose 359 and gas hose 360 ​​and switches whether or not room temperature gas is sent to gas hose 364 for the inner gas.

[0041] The outer gas switching valve SW2 includes solenoid valves 131 and 132. Solenoid valve 131 is located between gas hose 356 and gas hose 363 and switches whether or not cooled gas is sent to gas hose 365 for the outer gas. Solenoid valve 132 is located between gas hose 361 and gas hose 362 and switches whether or not room temperature gas is sent to gas hose 365 for the outer gas.

[0042] As described later, the welding torch 340 is equipped with a first gas passage and a second gas passage to achieve a double shielding gas system (inner gas and outer gas). The first gas passage is connected to a gas hose 364 for the inner gas, and the second gas passage is connected to a gas hose 365 for the outer gas.

[0043] By providing an inner gas switching valve SW1 and an outer gas switching valve SW2 in the gas supply device 15A, it is possible to select whether to cool only the inner gas, only the outer gas, both gases, or keep both gases at room temperature.

[0044] Furthermore, the gas supply device 15A may use components such as a flow control valve and a pressure control valve to use a mixture of cooled gas and room-temperature gas as the shielding gas. For example, considering radiant heat, it is possible to gradually cool the shielding gas during long welding sessions (to make the shielding performance equivalent to that at the start).

[0045] Figure 11 is a cross-sectional view showing the structure of the welding torch (MIG, double-shielded gas) used in Embodiment 2. The welding torch 340A shown in Figure 11 is basically a structure in which an outer gas shielding component is attached to the outside of the welding torch 40A shown in Figure 5.

[0046] Specifically, the welding torch 340A includes a liner 111 that guides the welding wire, a contact tip 170 positioned at the tip of the liner 111 to supply power to the welding wire, and a cylindrical gas nozzle 150 positioned to surround the contact tip 170.

[0047] The gas nozzle 150 includes an outer member 152, an inner member 151, and a tip member 153. A cooling water passage 191 is provided between the outer member 152 and the inner member 151, and cooling water is supplied from a cooling water hose 190.

[0048] The contact tip 170 is attached to the tip of the tip body 100, 101. The support member 180 is positioned to secure a gap between the gas nozzle 150 and the tip body 101, and although not shown, it is provided with a groove for gas to pass through. The gap between the gas nozzle 150 and the tip body 101 is a gas passage 181 through which the shielding gas passes.

[0049] The welding torch 340A further includes a gas nozzle 372 for outer gas, a support member 373 mounted around the gas nozzle 150 and supporting the gas nozzle 372, and a gas packing 374. The gas nozzle 372 is supplied with shielding gas for outer gas from a gas hose 371.

[0050] The welding torch 340A shown in Figure 11 includes a first gas passage 181 that generates a first gas flow around the contact tip 170, and a second gas passage 192 that generates a second gas flow around the first gas flow.

[0051] By appropriately setting the inner gas switching valve SW1 and outer gas switching valve SW2 shown in Figure 10 as needed, the shielding gas that has passed through the gas cooling passage 22 can be supplied to at least one of the first gas passage 181 and the second gas passage 192.

[0052] By appropriately setting the inner gas switching valve SW1 and outer gas switching valve SW2 shown in Figure 10 as needed, four different combinations of inner and outer gases are possible. One of these four combinations can be selected and used as needed.

[0053] The first combination involves using a cooled gas as the outer gas and a room-temperature gas as the inner gas.

[0054] In the welding apparatus 301 shown in Figure 10, by connecting the solenoid valve 334 of the inner gas switching valve SW1 and shutting off the solenoid valve 333, room temperature gas is supplied to the first gas passage 181. Furthermore, by connecting the solenoid valve 131 of the outer gas switching valve SW2 and shutting off the solenoid valve 132, cooled gas that has passed through the gas cooling passage 22 is supplied to the second gas passage 192.

[0055] The second combination involves using a cooled gas as the inner gas and a room-temperature gas as the outer gas.

[0056] In the welding apparatus 301 shown in Figure 10, by connecting the solenoid valve 333 of the inner gas switching valve SW1 and shutting off the solenoid valve 334, cooled gas that has passed through the gas cooling passage 22 is supplied to the first gas passage 181. Furthermore, by connecting the solenoid valve 132 of the outer gas switching valve SW2 and shutting off the solenoid valve 131, room temperature gas that has not passed through the gas cooling passage 22 is supplied to the second gas passage 192.

[0057] The third combination is one in which both the inner and outer gases are cooled gases.

[0058] In the welding apparatus 301 shown in Figure 10, by connecting the solenoid valve 333 of the inner gas switching valve SW1 and shutting off the solenoid valve 334, cooled gas that has passed through the gas cooling passage 22 is supplied to the first gas passage 181. Similarly, by connecting the solenoid valve 131 of the outer gas switching valve SW2 and shutting off the solenoid valve 132, cooled gas that has passed through the gas cooling passage 22 is supplied to the second gas passage 192.

[0059] The fourth combination is one in which both the inner and outer gases are at room temperature.

[0060] In the welding apparatus 301 shown in Figure 10, by connecting the solenoid valve 334 of the inner gas switching valve SW1 and shutting off the solenoid valve 333, room temperature gas is supplied to the first gas passage 181. Similarly, by connecting the solenoid valve 132 of the outer gas switching valve SW2 and shutting off the solenoid valve 131, room temperature gas is supplied to the second gas passage 192.

[0061] Figure 12 is a cross-sectional view showing the structure of a welding torch (TIG, double shielded gas) used in a modified example of Embodiment 2. Figure 13 is a diagram showing the flow of shielding gas and cooling water in the welding torch (TIG, double shielded gas) shown in Figure 12.

[0062] The welding torch 340B shown in Figure 12 is basically the same structure as the welding torch 40B shown in Figure 6, but with an inner gas passage provided around the welding electrode 270.

[0063] Specifically, the welding torch 340B includes a welding electrode 270 made of tungsten or the like, a cylindrical gas nozzle 250 positioned around the welding electrode 270, and a cylindrical gas nozzle 382 positioned between the welding electrode 270 and the gas nozzle 250. The welding electrode 270 is inserted into the collets 202 and 384. A support member 385 is positioned between the welding electrode 270 and the collet 384 and has a groove or hole for gas passage (not shown). A connecting member 383 is positioned outside the connection between the collet 384 and the gas nozzle 382. A support member 381 is positioned to ensure a gap between the collet 384 and the gas nozzle 250. The support member 381 has a groove or hole for gas passage (not shown).

[0064] The welding torch 340B shown in Figure 12 includes a first gas passage 281 that generates a first gas flow around the welding electrode 270, and a second gas passage 292 that generates a second gas flow around the first gas flow. As shown by the arrows in Figure 13, shielding gas flows through the first gas passage 281 and the second gas passage 292, and cooling water flows through the cooling water passage 291.

[0065] Figure 14 is an illustrative diagram showing the turbulence of the gas emitted from the torch when a normal double-shielded gas is supplied. In Figure 14, the corresponding elements are denoted by the same reference numerals as in Figure 12.

[0066] For example, in a welding process using a double-shielded torch, the inner gas has a smaller cross-sectional area in its gas passage compared to the outer gas, resulting in a high-speed airflow. As shown in Figure 14, the gas rolls up, and the shielding performance is very poor. Specifically, the turbulence of the inner gas makes the shielding gas prone to turbulence. This gas rolling up is particularly noticeable in aluminum welding, posing a significant problem.

[0067] Furthermore, in welding processes that involve feeding the wire in both forward and reverse directions, as applied to MIG or MAG welding, the repeated forward and reverse feeding motion of the wire makes it easy for the gas to roll up. Therefore, improving shielding performance is a major challenge.

[0068] Figure 15 is an illustrative diagram showing the turbulent state of the gas emitted from the torch when cooled outer gas is supplied. In Figure 15, as an example, the first of four possible combinations of inner and outer gases is shown.

[0069] The first combination involves using a cooled gas as the outer gas and a room-temperature gas as the inner gas.

[0070] In the welding apparatus 301 shown in Figure 10, by connecting the solenoid valve 334 of the inner gas switching valve SW1 and shutting off the solenoid valve 333, room temperature gas is supplied to the first gas passage 281, as shown in Figure 15. Furthermore, by connecting the solenoid valve 131 of the outer gas switching valve SW2 and shutting off the solenoid valve 132, cooled gas that has passed through the gas cooling passage 22 is supplied to the second gas passage 292.

[0071] By configuring the gas supply device 15A in this way, the inner gas remains unchanged while only the outer gas is cooled, achieving a double shield with a temperature difference. As a result, the denser, cooled shielding gas prevents the high-speed inner gas from being swirled up, thus improving shielding performance.

[0072] Furthermore, by cooling the outer gas while keeping the inner gas at room temperature, it is possible to improve shielding performance without changing the arc characteristics, while also cooling the welding torch and the base material.

[0073] Furthermore, this method of use is preferable when cooling the inner gas would further constrict the arc, potentially causing arc interruption or a decrease in arc starting performance.

[0074] Furthermore, the second combination, namely the combination of using a cooled gas as the inner gas and a room-temperature gas as the outer gas, may also be applied to the welding torch 340B shown in Figure 12.

[0075] In the welding apparatus 301 shown in Figure 10, by connecting the solenoid valve 333 of the inner gas switching valve SW1 and shutting off the solenoid valve 334, cooled gas that has passed through the gas cooling passage 22 is supplied to the first gas passage 281. Furthermore, by connecting the solenoid valve 132 of the outer gas switching valve SW2 and shutting off the solenoid valve 131, room temperature gas that has not passed through the gas cooling passage 22 is supplied to the second gas passage 292.

[0076] Thus, when the outer gas cools the inner gas at room temperature, increased efficiency due to arc constriction and arc stabilization can be expected. If the area near the arc is cooled too much, the arc temperature becomes unstable, which may reduce welding quality. Therefore, this method is useful when you want to constrict the arc but also stabilize it. In this case, the welding torch and base metal can also be cooled.

[0077] Furthermore, a third combination, namely a combination in which both the inner and outer gases are cooled gases, may also be applied to the welding torch 340B shown in Figure 12.

[0078] In the welding apparatus 301 shown in Figure 10, by connecting the solenoid valve 333 of the inner gas switching valve SW1 and shutting off the solenoid valve 334, cooled gas that has passed through the gas cooling passage 22 is supplied to the first gas passage 281. Similarly, by connecting the solenoid valve 131 of the outer gas switching valve SW2 and shutting off the solenoid valve 132, cooled gas that has passed through the gas cooling passage 22 is supplied to the second gas passage 292.

[0079] In this way, when both the outer and inner gases are cooled, it is possible to expect increased efficiency and improved shielding performance due to arc tightening, as well as cooling of the welding torch and base material.

[0080] [summary] (1) This disclosure relates to a welding apparatus. The welding apparatus 1 shown in Figure 1 comprises a welding torch 40 and a gas supply device 15 that supplies shielding gas to the welding torch 40. The gas supply device 15 includes a thermoelectric element 23 and a gas cooling passage 22 through which the shielding gas passes and which is cooled by the thermoelectric element 23.

[0081] (2) In the welding apparatus 1 described in paragraph 1, the welding torch 40 is a water-cooled torch having a water channel for cooling water. As shown in Figure 2, the gas supply device 15 is configured such that the high-temperature side of the thermoelectric element 23 dissipates heat to the cooling water, and the low-temperature side of the thermoelectric element 23 absorbs heat from the gas cooling passage 22.

[0082] (3) The welding apparatus 1 described in paragraph 2 further comprises circulation channels 61, 62, and 63 for circulating cooling water, as shown in Figures 1 and 2. The circulation channels 61, 62, and 63 are configured so that the cooling water flows in the order of the water-cooled torch (40) and the high-temperature side of the thermoelectric element 23.

[0083] (4) The welding apparatus 1A described in paragraph 2 further comprises circulation channels 65, 66, 67, and 68 for circulating cooling water. As shown in Figure 9, the circulation channels 65, 66, 67, and 68 are configured so that cooling water flows in parallel to the water-cooled torch (40) and the high-temperature side of the thermoelectric element 23.

[0084] (5) In the welding apparatus 301 described in paragraph 1, the welding torches 340A and 340B shown in Figures 11, 12 and 13 include first gas passages 181 and 281 that generate a first gas flow around the contact tip 170 or welding electrode 270, and second gas passages 192 and 292 that generate a second gas flow around the first gas flow. Shielding gas that has passed through the gas cooling passage 22 is supplied to at least one of the first gas passages 181 and 281 and the second gas passages 192 and 292.

[0085] (6) In the welding apparatus 301 described in paragraph 5, the first gas passages 181 and 281 are supplied with shielding gas that has passed through the gas cooling passage 22, and the second gas passages 192 and 292 are supplied with shielding gas that has not passed through the gas cooling passage 22.

[0086] (7) In the welding apparatus 301 described in paragraph 5, the second gas passages 192 and 292 are supplied with shielding gas that has passed through the gas cooling passage 22, and the first gas passages 181 and 281 are supplied with shielding gas that has not passed through the gas cooling passage 22.

[0087] (8) In the welding apparatus 301 described in paragraph 5, the shielding gas that has passed through the gas cooling passage 22 is supplied to both the first gas passages 181, 281 and the second gas passages 192, 292.

[0088] (9) In the welding apparatus 301 described in paragraph 5, as shown in Figure 10, the gas supply device 15A is configured to switch between supplying shielding gas that has passed through the gas cooling passage 22 to the first gas passages 181 and 281, and supplying shielding gas that has not passed through the gas cooling passage 22.

[0089] (10) In the welding apparatus 301 described in paragraph 5 or 9, as shown in Figure 10, the gas supply device 15A is configured to switch between supplying shielding gas that has passed through the gas cooling passage 22 to the second gas passages 192, 292, and supplying shielding gas that has not passed through the gas cooling passage 22.

[0090] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than by the description of the embodiments above, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Explanation of Symbols]

[0091] 1,1A,301 Welding equipment, 10,110 Gas supply source, 15,15A Gas supply device, 20 Thermoelectric element cooling unit, 21 Cooling water passage, 22 Gas cooling passage, 23 Thermoelectric element, 30,131,132,333,334 Solenoid valve, 40,40A,40B,340,340A,340B Welding torch, 50 Cooling water supply source, 51,52,53,351,352,354,355,356,357,359,360,361,362,363,364,365,371 Gas hose, 61,62,63,65,66,67,68 Circulation water passage, 100,101 Tip body, 137, 150, 172, 250, 372, 382 Gas nozzle, 151, 282 Inner member, 152, 283 Outer member, 153 Tip member, 170 Contact tip, 180, 373, 381, 385 Support member, 181, 281, 192, 292 Gas passage, 190 Cooling water hose, 191, 291 Cooling water channel, 200, 202, 384 Collet, 201, 280 Collet body, 270 Welding electrode, 353, 358 Flow divider valve, 374 Gas packing, 383 Connecting member, P1, P2, P3, P4 Port, SW1 Inner gas switching valve, SW2 Outer gas switching valve.

Claims

1. Welding torch and The system includes a gas supply device that supplies shielding gas to the welding torch, The aforementioned gas supply device is Thermoelectric element, A welding apparatus comprising a gas cooling passage configured for the passage of the shielding gas and cooled by the thermoelectric element.

2. The welding torch is a water-cooled torch having a water channel for cooling water, The welding apparatus according to claim 1, wherein the gas supply device is configured such that the high-temperature side of the thermoelectric element dissipates heat to the cooling water, and the low-temperature side of the thermoelectric element absorbs heat from the gas cooling passage.

3. The system further comprises a circulating water channel for circulating the aforementioned cooling water, The welding apparatus according to claim 2, wherein the circulating water channel is configured such that the cooling water flows in the order of the water-cooled torch and the high-temperature side of the thermoelectric element.

4. The system further comprises a circulating water channel for circulating the aforementioned cooling water, The welding apparatus according to claim 2, wherein the circulating water channel is configured such that the cooling water flows parallel to the water-cooled torch and the high-temperature side of the thermoelectric element.

5. The aforementioned welding torch is A first gas passage that generates a first gas flow around the welding electrode, The system includes a second gas passage that generates a second gas flow around the first gas flow, The welding apparatus according to claim 1, wherein the shielding gas that has passed through the gas cooling passage is supplied to at least one of the first gas passage and the second gas passage.

6. The welding apparatus according to claim 5, wherein the first gas passage is supplied with the shielding gas after it has passed through the gas cooling passage, and the second gas passage is supplied with the shielding gas that has not passed through the gas cooling passage.

7. The welding apparatus according to claim 5, wherein the shielding gas that has passed through the gas cooling passage is supplied to the second gas passage, and the shielding gas that has not passed through the gas cooling passage is supplied to the first gas passage.

8. The welding apparatus according to claim 5, wherein the shielding gas that has passed through the gas cooling passage is supplied to both the first gas passage and the second gas passage.

9. The welding apparatus according to claim 5, wherein the gas supply device is configured to switch between supplying the shielding gas to the first gas passage after it has passed through the gas cooling passage, or supplying the shielding gas that has not passed through the gas cooling passage.

10. The welding apparatus according to claim 5 or 9, wherein the gas supply device is configured to switch between supplying the shielding gas to the second gas passage after it has passed through the gas cooling passage, or supplying the shielding gas that has not passed through the gas cooling passage.

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