Swing type composite welding gun for narrow gap welding

Abstract

The invention discloses a swing type composite welding gun for narrow gap welding, and belongs to the technical field of welding, the swing type composite welding gun comprises a welding gun shell assembly, the welding gun shell assembly is internally provided with an MIG welding gun main body, a TIG welding gun main body and a swing mechanism used for driving the TIG welding gun main body to swing, a wire distance adjusting device used for driving the MIG welding gun body so as to adjust the distance between wires of the MIG welding gun body and the TIG welding gun body is arranged in the welding gun shell assembly, and a protective gas supply device for conveying gas is arranged in the welding gun shell assembly. The TIG electric arc and the MIG electric arc can be ignited at the same time in the narrow-gap groove, the TIG electric arc is in front of the MIG electric arc in the working process, the stable coupling effect can be formed when the two electric arcs are combusted in the groove, the welding process is very stable, and almost no splashing is generated.

Description

Technical Field

[0001] The present invention relates to the field of welding technology, and in particular to an oscillating composite welding gun for narrow gap welding. Background Technology

[0002] Against the backdrop of increasingly fierce industrial competition among countries, industrial facilities and equipment are gradually being produced and developed in the direction of large-scale equipment, complex structure, diversified functions, and intelligent parameters. Metal structures of basic components such as thick plates and thick pipes are widely used in offshore platforms, shipbuilding, aerospace, and pipeline engineering. As a result, higher requirements are placed on the manufacture of large metal structures. As a typical representative of a country's industrial level, welding production also places higher requirements on its welding quality, welding level, and welding efficiency. Although traditional welding methods such as submerged arc welding and gas shielded welding can improve production efficiency at high current levels, their heat input will be too large as the current is too high, resulting in coarse weld grains, decreased mechanical properties, and poor adaptability to welded structures.

[0003] The narrow gap welding method has the advantages of low equipment cost, high welding efficiency, low welding material consumption, high welding quality, strong welding position adaptability, and low energy consumption. It is often used in the welding production of large metal components such as thick plates and thick pipes. In the narrow gap welding process, the specially designed narrow gap welding torch can penetrate into the groove for welding. Because the spacing of the groove is small, the shielding gas can be restrained to prevent it from diffusing into the atmosphere, so that the shielding gas can fill the groove for full-position protection of welding, and minimize the defects such as pores and slag inclusions in the welded joint.

[0004] Currently, the welding methods involved in narrow gap welding mainly use external mechanical devices or energy fields to make a single arc swing in the groove, so that the arc burns at the side wall to melt the side wall and eliminate the side wall non-fusion defect. The advantages of a single heat source are limited, and welding quality and welding efficiency are often not taken into account. The present invention provides a composite heat source welding gun for narrow gap welding. SUMMARY OF THE INVENTION

[0005] The purpose of the present invention is to provide a swing type composite welding gun for narrow gap welding to solve the problems raised in the above background technology.

[0006] In order to achieve the above purpose, the present invention adopts the following technical solutions: A swing type composite welding gun for narrow gap welding, comprising a welding gun housing assembly, wherein a MIG welding gun body, a TIG welding gun body and a swing mechanism for driving the TIG welding gun body to swing are arranged in the welding gun housing assembly, wherein a wire pole spacing adjustment device for driving the MIG welding gun body is arranged in the welding gun housing assembly, and the distance between the wire pole of the MIG welding gun body and the wire pole of the TIG welding gun body is adjusted by the wire pole spacing adjustment device, and a protective gas supply device for conveying gas is arranged in the welding gun housing assembly.

[0007] Furthermore, the welding gun housing assembly includes a welding gun frame, the top of the welding gun frame is provided with an upper panel, one side of the upper surface of the upper panel is provided with a MIG welding gun electrical port, the other side of the upper surface of the upper panel is provided with two gas quick-plug interfaces, the upper surface of the upper panel is provided with a TIG welding gun electrical port, and the TIG welding gun electrical port is located between the two gas quick-plug interfaces.

[0008] Furthermore, the TIG welding gun body includes an upper end cover and a lower end cover of the TIG welding gun, a TIG welding gun middle sleeve is arranged between the upper end cover and the lower end cover of the TIG welding gun, a tungsten electrode conductive rod is arranged at the bottom of the lower end cover of the TIG welding gun, the joints of the upper end cover of the TIG welding gun, the middle sleeve of the TIG welding gun and the lower end cover of the TIG welding gun are sealed by brazing, and the middle sleeve of the TIG welding gun includes an internal hollow tube and a middle hollow sleeve, and the internal hollow tube is arranged in the middle hollow sleeve.

[0009] Furthermore, the MIG welding gun body includes a wire feeding tube sleeve, the bottom end of which is threadedly connected to a lower wire feeding tube, an upper end cover of the MIG welding gun and a lower end cover of the MIG welding gun are arranged on the outer peripheral side of the wire feeding tube sleeve, a middle capillary sleeve is arranged between the upper end cover of the MIG welding gun and the lower end cover of the MIG welding gun, and cavities are arranged between the upper and lower sides of the middle capillary sleeve and the upper end cover of the MIG welding gun and the lower end cover of the MIG welding gun.

[0010] Furthermore, the swing mechanism includes a nylon clamp, which is connected to the TIG welding gun body, and one side of the nylon clamp is provided with a second self-lubricating bearing, which is connected to the inner wall of the welding gun housing assembly through a bearing support frame, and a micro slide is provided on the top of one side of the welding gun housing assembly, and a motion conduction rod is slidably connected to the micro slide, and a TIG welding gun connector connected to the TIG welding gun body is provided at the end of the motion conduction rod.

[0011] Furthermore, the wire electrode spacing adjustment device includes a MIG welding gun clamp connected to the MIG welding gun body, and the front and rear sides of the inner wall of the welding gun housing assembly are provided with slide rails, and the MIG welding gun clamp is slidably connected to the slide rails through two sliders. An insulating sleeve is provided between the MIG welding gun body and the MIG welding gun clamp to ensure that the MIG welding gun body and the MIG welding gun clamp are insulated. The right side of the MIG welding gun clamp is threadedly connected to two spacing adjustment screws, and the end of the spacing adjustment screw extends out of the welding gun housing assembly and is provided with a handwheel. The spacing adjustment screw is rotatably connected to the welding gun housing assembly through a self-lubricating bearing three.

[0012] Furthermore, the protective gas supply device includes a right protective gas vent pipe and a left protective gas vent pipe, the right protective gas vent pipe and the left protective gas vent pipe are parallel to the TIG welding gun body and the MIG welding gun body respectively, and a protective gas hood is provided on the right protective gas vent pipe and the left protective gas vent pipe, and two side wall capillary copper tubes are provided in the protective gas hood, and one end of the side wall capillary copper tube extends out of the welding gun housing assembly and is provided with a gas quick interface.

[0013] Furthermore, the right side of the welding gun housing assembly is rotatably connected to a screw rod through a self-lubricating bearing, the screw rod is threadedly connected to the protective gas hood, and the left side of the welding gun housing assembly is sleeved with a polished rod through a linear bearing, and the bottom end of the polished rod is connected to the protective gas hood.

[0014] Furthermore, a nylon ladder frame is provided in the welding gun housing assembly, and a right water-cooled copper plate and a left water-cooled copper block are provided on both sides of the nylon ladder frame, and a nylon block is provided between the right water-cooled copper plate and the left water-cooled copper block to prevent the two copper plates from short-circuiting due to poor insulation protection, and channels for conveying cold water are provided in the right water-cooled copper plate and the left water-cooled copper block.

[0015] Compared with the prior art, the beneficial effects of the present invention are: The TIG arc and the MIG arc can be ignited simultaneously in the narrow gap groove. During operation, the TIG arc is in front and the MIG arc is in the back. When the two arcs burn in the groove, a stable coupling effect can be formed. The welding process is very stable and almost no spatter is generated. Due to the coupling effect of the arc, the path of the molten droplet transition can be changed, the impact of the molten droplet on the liquid molten pool can be reduced, and the finger-shaped penetration at the bottom of the groove can be avoided. The TIG arc presents a swinging mode during operation, which can expand the arc burning area of ​​the TIG arc, so that a larger proportion of the arc acts on the side wall, and more arc heat input is conducted to both sides of the groove, fully melting the side wall, and eliminating the side wall unfused defects in narrow gap welding. The MIG arc plays the role of filling the weld metal. Due to the melting effect of the front TIG arc on the side wall of the groove, the filled liquid metal can be spread to both sides of the groove to the maximum extent under the action of surface tension, and a concave weld is formed after solidification, which is conducive to the filling of the subsequent weld metal. Brief Description of the Figures

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without creative work.

[0017] Figure 1 is a schematic diagram of the overall structure of the present invention; Figure 2 is a schematic diagram of the structure inside the welding gun housing assembly of the present invention; Figure 3 It is a structural schematic diagram of the protective air supply device of the present invention; Figure 4 is a schematic structural diagram of the TIG welding gun body of the present invention; Figure 5 It is a schematic diagram of the structure of the MIG welding gun body of the present invention.

[0018] In the figure: 1. welding gun frame; 2. upper panel; 3. MIG welding gun electrical port; 4. TIG welding gun electrical port; 5. gas quick-connect interface; 6. hand wheel; 7. self-lubricating bearing 1; 8. lead screw; 9. micro slide; 10. linear bearing; 11. polished rod; 12. MIG welding gun body; 13. slide rail; 14. slide block; 15. motion transmission rod; 16. TIG welding gun connector; 17. TIG welding gun body; 18. self-lubricating bearing 2; 19. bearing support frame; 20. nylon clamp; 21. insulating sleeve; 22. MIG welding gun clamp; 23. self-lubricating bearing 3 ; 24. Spacing adjustment screw rod; 25. Nylon ladder frame; 26. Right water-cooled copper plate; 27. Shielding gas cover; 28. Right shielding gas vent pipe; 29. ​​Left shielding gas vent pipe; 30. Gas quick connector; 31. Side wall capillary copper tube; 32. Left water-cooled copper block; 33. Nylon block; 34. TIG welding gun upper cover; 35. TIG welding gun middle sleeve; 36. TIG welding gun lower cover; 37. Tungsten electrode conductive rod; 38. Wire feed tube sleeve; 39. MIG welding gun upper cover; 40. Middle capillary sleeve; 41. MIG welding gun lower cover; 42. Lower wire feed tube. Specific implementation method

[0019] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] Please refer to Figure 1-Figure 5 , the present invention provides a technical solution: If Figure 1 and Figure 2 As shown, a swing type composite welding gun for narrow gap welding includes a welding gun housing assembly, in which a MIG welding gun body 12, a TIG welding gun body 17 and a swing mechanism for driving the TIG welding gun body 17 to swing are arranged, and a wire pole spacing adjustment device for driving the MIG welding gun body 12 is arranged in the welding gun housing assembly, and the distance between the wire poles of the MIG welding gun body 12 and the TIG welding gun body 17 is adjusted by the wire pole spacing adjustment device, and a protective gas supply device for conveying gas is arranged in the welding gun housing assembly.

[0021] If Figure 1As shown, the welding gun housing assembly includes a welding gun frame 1, and the welding gun frame 1 includes front, rear, left and right panels, and the panel material is aluminum alloy. An upper panel 2 is arranged on the top of the welding gun frame 1, and the welding gun upper panel 2 is made of bakelite insulation material. A MIG welding gun electrical port 3 is arranged on one side of the upper surface of the upper panel 2, and two gas quick-plug interfaces 5 are arranged on the other side of the upper surface of the upper panel 2. A TIG welding gun electrical port 4 is arranged on the upper surface of the upper panel 2, and the TIG welding gun electrical port 4 is located between the two gas quick-plug interfaces 5.

[0022] If Figure 4 As shown in FIG. 1 , the TIG welding gun body 17 includes a TIG welding gun upper end cover 34 and a TIG welding gun lower end cover 36, a TIG welding gun middle sleeve 35 is arranged between the TIG welding gun upper end cover 34 and the TIG welding gun lower end cover 36, a tungsten electrode conductive rod 37 is arranged at the bottom of the TIG welding gun lower end cover 36, the joints of the TIG welding gun upper end cover 34, the TIG welding gun middle sleeve 35 and the TIG welding gun lower end cover 36 are sealed by brazing, the TIG welding gun middle sleeve 35 includes an internal hollow tube and a middle hollow sleeve, and the internal hollow The tube is arranged in the middle hollow sleeve, the tungsten electrode conductive rod 37 is threadedly connected with the lower end cover 36 of the TIG welding gun, the upper end cover 34 of the TIG welding gun, the middle sleeve 35 of the TIG welding gun and the lower end cover 36 of the TIG welding gun are all made of copper material, when cooling the TIG welding gun body 17, the cooling water enters the inner hollow tube through the water inlet reserved on the upper end cover of the TIG welding gun upper end cover 34, then enters between the inner hollow tube and the middle hollow sleeve through the bottom end of the inner hollow tube, and finally is discharged through the water outlet reserved on one side of the middle hollow sleeve.

[0023] If Figure 5 As shown in FIG. 1 , the MIG welding gun body 12 includes a wire feeding tube sleeve 38, the bottom end of the wire feeding tube sleeve 38 is threadedly connected to a lower wire feeding tube 42, an upper end cover 39 of the MIG welding gun and a lower end cover 41 of the MIG welding gun are arranged on the outer peripheral side of the wire feeding tube sleeve 38, a middle capillary sleeve 40 is arranged between the upper end cover 39 of the MIG welding gun and the lower end cover 41 of the MIG welding gun, and the joints of the wire feeding tube sleeve 38, the upper end cover 39 of the MIG welding gun, the middle capillary sleeve 40 and the lower end cover 41 of the MIG welding gun are all sealed by brazing, and the middle capillary sleeve 40 The upper and lower sides are provided with cavities between the upper end cover 39 of the MIG welding gun and the lower end cover 41 of the MIG welding gun. Specifically, when cooling the MIG welding gun body 12, the cooling water enters the cavity between the upper side of the middle capillary sleeve 40 and the upper end cover 39 of the MIG welding gun through the water inlet reserved on the upper end cover 39 of the MIG welding gun, and then flows into the cavity between the lower side of the middle capillary sleeve 40 and the lower end cover 41 of the MIG welding gun through the capillary on the middle capillary sleeve 40, and finally flows out through the water outlet reserved at the bottom of one side of the middle capillary sleeve 40.

[0024] If Figure 2 ​​As shown, the swing mechanism includes a nylon clamp 20, which is connected to the TIG welding gun body 17. A self-lubricating bearing 18 is provided on one side of the nylon clamp 20. The self-lubricating bearing 18 is connected to the inner wall of the welding gun housing assembly through a bearing support frame 19. A micro slide 9 is provided on the top of one side of the welding gun housing assembly. A motion conduction rod 15 is slidably connected to the micro slide 9. A TIG welding gun connector 16 connected to the TIG welding gun body 17 is provided at the end of the motion conduction rod 15. The motion conduction rod 15 and the TIG welding gun connector 16 are driven by the micro slide 9 to make the TIG welding gun body 17 perform a reciprocating swing motion. When the TIG welding gun body 17 is energized, a reciprocating swinging TIG arc is formed.

[0025] Furthermore, the wire electrode spacing adjustment device includes a MIG welding gun fixture 22 connected to the MIG welding gun body 12, and the front and rear sides of the inner wall of the welding gun housing assembly are provided with slide rails 13, and the MIG welding gun fixture 22 is slidably connected to the slide rails 13 through two sliders 14. An insulating sleeve 21 is provided between the MIG welding gun body 12 and the MIG welding gun fixture 22 to ensure that the MIG welding gun body 12 is insulated from the MIG welding gun fixture 22, and the inclination angle of the MIG welding gun body 12 is fixed by the MIG welding gun fixture 22. There is a threaded hole of a certain depth on the right side of the MIG welding gun fixture 22. The MIG welding gun fixture 22 is threadedly connected to two spacing adjustment screws 24 through the threaded hole. The end of the spacing adjustment screw 24 extends out of the welding gun housing assembly and is provided with a handwheel 6. The spacing adjustment screw 24 is rotatably connected to the welding gun housing assembly through a self-lubricating bearing 3 23. By rotating the handwheel 6, the MIG welding gun fixture 22 and the MIG welding gun body 12 are moved under the action of the thread on the spacing adjustment screw 24 to achieve accurate adjustment of the wire electrode spacing. The adjustment range is 3mm-20mm.

[0026] If Figure 3As shown, the protective gas supply device includes a right protective gas vent pipe 28 and a left protective gas vent pipe 29, which are parallel to the TIG welding gun body 17 and the MIG welding gun body 12 respectively, and the right protective gas vent pipe 28 and the left protective gas vent pipe 29 are copper tubes with a thickness of 8 mm. The top ends of the right protective gas vent pipe 28 and the left protective gas vent pipe 29 are respectively connected to the right water-cooled copper plate 26 and the left water-cooled copper block 32, and an air intake channel is reserved on the right water-cooled copper plate 26 and the left water-cooled copper block 32. The protective gas enters the right protective gas vent pipe 28 and the left protective gas vent pipe 29 from the air intake channel. When the protective gas flows through the right protective The gas vent pipe 28 and the left protective gas vent pipe 29 play a certain calming role, and the gas flows out through the outlet of the right protective gas vent pipe 28 and the left protective gas vent pipe 29. The right protective gas vent pipe 28 and the left protective gas vent pipe 29 are flat structures that can inhibit gas leakage. The outlet sides of the right protective gas vent pipe 28 and the left protective gas vent pipe 29 are provided with grooves to block the protective gas from flowing out along the grooves. The right protective gas vent pipe 28 and the left protective gas vent pipe 29 are provided with protective gas hoods 27. Two side wall capillary copper tubes 31 are provided in the protective gas hood 27. One end of the side wall capillary copper tube 31 extends out of the welding gun housing assembly and is provided with a gas quick interface 30.

[0027] Furthermore, the right side of the welding gun housing assembly is rotatably connected to a screw rod 8 through a self-lubricating bearing 7, and the screw rod 8 is threadedly connected to the protective gas hood 27. The left side of the welding gun housing assembly is sleeved with a polished rod 11 through a linear bearing 10, and the bottom end of the polished rod 11 is connected to the protective gas hood 27.

[0028] If Figure 3 As shown in FIG. 1 , a nylon step frame 25 is provided in the welding gun housing assembly, and a right water-cooled copper plate 26 and a left water-cooled copper block 32 are provided on both sides of the nylon step frame 25, respectively. A nylon block 33 is provided between the right water-cooled copper plate 26 and the left water-cooled copper block 32 to prevent the two copper plates from short-circuiting in the case of poor insulation protection. Channels for conveying cold water are provided in the right water-cooled copper plate 26 and the left water-cooled copper block 32. External cold water is first injected into the TIG welding gun body 17 and then injected into the channel in the left water-cooled copper block 32 through the water inlet above the left water-cooled copper block 32 under the conveyance of the hose, and then injected into the channel in the right water-cooled copper plate 26 from the water outlet and hose below the left water-cooled copper block 32 and the water inlet above the right water-cooled copper plate 26, and finally injected into the MIG welding gun body 12 through the water outlet and hose below the right water-cooled copper plate 26 and flows out from the water outlet on the MIG welding gun body 12.

[0029] ​​The working process of this embodiment is as follows: the composite welding gun requires the TIG welder and the MIG welder to work at the same time. The two welders and the swing mechanism, the wire electrode spacing adjustment device, the protective gas supply device, and the cooling structure of the TIG welding gun body 17 and the MIG welding gun body 12 are all controlled by PLC integrated linkage. Before welding begins, the water supply device and the protective gas supply device are first turned on. After 3 seconds, the TIG arc is started and ignited. At the same time, the swing mechanism is turned on so that the TIG arc swings in the groove. After 1 second, the MIG arc is ignited and welding is performed at a certain welding speed. The swing mechanism can pre-set the swing parameters through the swing system: such as the swing speed, swing amplitude, side wall residence time, etc.

[0030] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A swing type composite welding gun for narrow gap welding, characterized in that: The invention comprises a welding gun housing assembly, wherein a MIG welding gun body (12), a TIG welding gun body (17) and a swing mechanism for driving the TIG welding gun body (17) to swing are arranged in the welding gun housing assembly, a wire pole spacing adjustment device for driving the MIG welding gun body (12) is arranged in the welding gun housing assembly, and the distance between the wire pole of the MIG welding gun body (12) and the wire pole of the TIG welding gun body (17) is adjusted by the wire pole spacing adjustment device, and a protective gas supply device for conveying gas is arranged in the welding gun housing assembly.

2. The oscillating composite welding gun for narrow gap welding according to claim 1, characterized in that: The welding gun housing assembly comprises a welding gun frame (1), an upper panel (2) is arranged on the top of the welding gun frame (1), a MIG welding gun electrical connection port (3) is arranged on one side of the upper surface of the upper panel (2), two gas quick-connect interfaces (5) are arranged on the other side of the upper surface of the upper panel (2), a TIG welding gun electrical connection port (4) is arranged on the upper surface of the upper panel (2), and the TIG welding gun electrical connection port (4) is located between the two gas quick-connect interfaces (5).

3. The oscillating composite welding gun for narrow gap welding according to claim 1, characterized in that: The TIG welding gun body (17) comprises a TIG welding gun upper end cover (34) and a TIG welding gun lower end cover (36); a TIG welding gun middle sleeve (35) is arranged between the TIG welding gun upper end cover (34) and the TIG welding gun lower end cover (36); a tungsten electrode conductive rod (37) is arranged at the bottom of the TIG welding gun lower end cover (36); the joint between the TIG welding gun upper end cover (34), the TIG welding gun middle sleeve (35) and the TIG welding gun lower end cover (36) is sealed by brazing; the TIG welding gun middle sleeve (35) comprises an inner hollow tube and a middle hollow sleeve; the inner hollow tube is arranged in the middle hollow sleeve.

4. The oscillating composite welding gun for narrow gap welding according to claim 1, characterized in that: The MIG welding gun body (12) comprises a wire feeding tube sleeve (38), the bottom end of the wire feeding tube sleeve (38) is threadedly connected to a lower wire feeding tube (42), an MIG welding gun upper end cover (39) and a MIG welding gun lower end cover (41) are arranged on the outer peripheral side of the wire feeding tube sleeve (38), a middle capillary sleeve (40) is arranged between the MIG welding gun upper end cover (39) and the MIG welding gun lower end cover (41), and cavities are arranged between the upper and lower sides of the middle capillary sleeve (40) and the MIG welding gun upper end cover (39) and the MIG welding gun lower end cover (41), respectively.

5. The oscillating composite welding gun for narrow gap welding according to claim 1, characterized in that: The swing mechanism comprises a nylon clamp (20), the nylon clamp (20) being connected to a TIG welding gun body (17), a self-lubricating bearing 2 (18) being provided on one side of the nylon clamp (20), the self-lubricating bearing 2 (18) being connected to the inner wall of a welding gun housing assembly via a bearing support frame (19), a micro slide (9) being provided on the top of one side of the welding gun housing assembly, a motion conduction rod (15) being slidably connected to the micro slide (9), and a TIG welding gun connector (16) being connected to the TIG welding gun body (17) being provided at the end of the motion conduction rod (15).

6. The oscillating composite welding gun for narrow gap welding according to claim 1, characterized in that: The wire electrode spacing adjustment device comprises a MIG welding gun clamp (22) connected to a MIG welding gun body (12); slide rails (13) are provided on both the front and rear sides of the inner wall of the welding gun housing assembly; the MIG welding gun clamp (22) is slidably connected to the slide rails (13) via two sliding blocks (14); an insulating sleeve (21) is provided between the MIG welding gun body (12) and the MIG welding gun clamp (22); two spacing adjustment screw rods (24) are threadedly connected to the right side of the MIG welding gun clamp (22); the end of the spacing adjustment screw rod (24) extends out of the welding gun housing assembly and is provided with a hand wheel (6); the spacing adjustment screw rod (24) is rotatably connected to the welding gun housing assembly via a self-lubricating bearing three (23).

7. The oscillating composite welding gun for narrow gap welding according to claim 1, characterized in that: The protective gas supply device comprises a right protective gas ventilation pipe (28) and a left protective gas ventilation pipe (29); the right protective gas ventilation pipe (28) and the left protective gas ventilation pipe (29) are parallel to a TIG welding gun body (17) and a MIG welding gun body (12), respectively; the right protective gas ventilation pipe (28) and the left protective gas ventilation pipe (29) are copper pipes with a thickness of 8 mm; a protective gas hood (27) is provided on the right protective gas ventilation pipe (28) and the left protective gas ventilation pipe (29); two side wall capillary copper tubes (31) are provided in the protective gas hood (27); one end of the side wall capillary copper tube (31) extends out of the welding gun housing assembly and is provided with a gas quick interface (30).

8. The oscillating composite welding gun for narrow gap welding according to claim 7, characterized in that: The right side of the welding gun housing assembly is rotatably connected to a screw rod (8) via a self-lubricating bearing (7), and the screw rod (8) is threadedly connected to a protective gas hood (27). The left side of the welding gun housing assembly is sleeved with a polished rod (11) via a linear bearing (10), and the bottom end of the polished rod (11) is connected to the protective gas hood (27).

9. The oscillating composite welding gun for narrow gap welding according to claim 1, characterized in that: A nylon step frame (25) is arranged in the welding gun housing assembly, and a right water-cooled copper plate (26) and a left water-cooled copper block (32) are arranged on both sides of the nylon step frame (25), respectively. A nylon block (33) is arranged between the right water-cooled copper plate (26) and the left water-cooled copper block (32) to prevent the two copper plates from contacting and short-circuiting in the case of poor insulation protection. Channels for conveying cold water are provided in the right water-cooled copper plate (26) and the left water-cooled copper block (32).

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