Metal pipeline welding device for municipal construction and welding method thereof

Abstract

The invention relates to the field of municipal metal pipeline construction, and discloses a metal pipeline welding device for municipal construction and a welding method thereof.The metal pipeline welding device comprises a limiting component, and a welding component is rotationally mounted in the limiting component; the limiting component comprises a second arc-shaped frame, a connecting frame is welded to the outer surface of the middle of the second arc-shaped frame, a first arc-shaped frame is rotationally connected to the bottom end of the second arc-shaped frame, a threaded positioning rod is in threaded connection with one end of the top of the connecting frame, and a hinge is arranged at the bottom connecting position of the second arc-shaped frame and the first arc-shaped frame. Through cooperative operation between the welding part and the limiting part, the municipal metal pipeline can be automatically welded, the labor intensity of workers is reduced, the situation that the workers conduct welding work in a severe environment is avoided, meanwhile, the welding efficiency can be guaranteed through automatic welding, and the use requirement of people for the welding device is met.

Description

Technical Field

[0001] The invention relates to the field of municipal metal pipeline construction, and in particular to a metal pipeline welding device for municipal construction and a welding method thereof. Background Art

[0002] Metal pipes in municipal construction are widely used in various urban infrastructure construction due to their high strength, corrosion resistance and long life. For example, metal pipes (such as steel pipes, cast iron pipes, and stainless steel pipes) are often used in urban tap water supply systems to ensure that clean water is stably delivered to residential and industrial areas. These pipes can withstand high water pressure, reduce the risk of leakage, and ensure the quality and efficiency of water supply.

[0003] During the municipal pipeline construction process, it is necessary to weld the pipes, and welding is one of the main ways to connect metal pipes. Pipes of different lengths can be connected by welding to form a complete pipeline system. In municipal construction, metal pipe welding can ensure the continuity and integrity of the pipeline system, thereby meeting the needs of urban water supply, drainage, gas and other infrastructure;

[0004] However, during the use of the existing metal pipe welding device for municipal construction, workers need to hold the device for a long time for welding. Therefore, the current welding device cannot perform automatic welding and cannot meet the use requirements. In addition, the workers are more tired when the welding environment is relatively harsh. For example, in cold weather, workers need to squat inside the construction trench for a long time to perform welding work. Some construction environments also have stagnant water, which seriously endangers the health of the workers. Therefore, the existing metal pipe welding device for municipal construction cannot meet the use requirements. Summary of the invention

[0005] The purpose of the present invention is to provide a metal pipe welding device for municipal construction and a welding method thereof, so as to solve the following technical problem: how to make the metal pipe welding device for municipal construction have automatic welding function, reduce the labor intensity of the staff and improve the welding efficiency.

[0006] The object of the present invention can be achieved by the following technical solution: A metal pipe welding device for municipal construction, comprising: a limiting component, wherein a welding component is rotatably installed inside the limiting component;

[0007] The limiting component includes a second arc frame, a connecting frame is welded on the middle outer surface of the second arc frame, the bottom end of the second arc frame is rotatably connected to the first arc frame, a threaded positioning rod is threadedly connected to the top end of the connecting frame, a hinge is provided at the connection between the second arc frame and the bottom of the first arc frame, an annular slideway is provided between the second arc frame and the first arc frame, and the outer surface edges of the second arc frame and the first arc frame are evenly and symmetrically threadedly connected with positioning screws;

[0008] The top of the first arc frame is symmetrically provided with threaded holes, the top of the second arc frame is symmetrically provided with fastening screws, the inner surfaces of the second arc frame and the first arc frame and the edge of the annular slideway are provided with gear rails, and the inner surfaces of the second arc frame and the first arc frame on one side of the annular slideway are evenly provided with limiting columns;

[0009] A controller is fixedly installed on the outer surface of one side of the connecting frame, a driving motor is fixedly installed on the outer surface of one end of the connecting frame, a helical gear shaft is rotatably clamped on the middle edge of the second arc-shaped frame, one end of the helical gear shaft is fixedly connected to the driving gear, and one end of the driving motor is fixedly connected to a helical gear meshing with the helical gear shaft.

[0010] As a preferred embodiment of the present invention: the welding component includes an arc frame, a limiting slide groove is provided on one side of the arc frame, a transmission tooth groove is provided on the other side of the arc frame, welding wire conveying lines and power supply wires are evenly arranged on the outer surfaces of both ends of the arc frame, and the outer surfaces of both ends of the arc frame are fixedly installed, and the inner surfaces of the edges of both ends of the arc frame are rotatably clamped with transmission components, one end of the transmission component is movably connected to the welding component, and the inner surfaces of both ends of the arc frame are symmetrically provided with limiting frames, and both ends of the arc frame are threadedly connected with threaded rods, and one end of the threaded rods is fixedly connected with a cleaning block.

[0011] As a preferred solution of the present invention: the transmission assembly includes a transmission gear plate, a transmission gear plate is fixedly connected to the center of one side of the transmission gear plate, and a clamping column is arranged on the edge of the other side of the transmission gear plate.

[0012] As a preferred embodiment of the present invention: the welding assembly includes a limit frame, the outer surfaces of both ends of the limit frame are provided with clamping grooves, the inner surface of the limit frame is provided with a limit slide, the side center thread of the limit frame is connected with a welding head, the outer surface of the welding head is provided with a connecting port, and the outer surface of one end of the welding head is provided with a rotating block.

[0013] As a preferred solution of the present invention: the arc frame is rotationally connected with the inside of the first arc frame and the second arc frame through an annular slide, the limit column is slidingly connected with the outer surface of the arc frame through a limit slide groove, and the driving gear inside the second arc frame is meshed and connected with the outer surface of the arc frame through a transmission tooth groove.

[0014] As a preferred solution of the present invention: the welding wire conveying line and the power supply wire are fixedly connected to the welding head through the connecting port, the limiting frame is slidably connected to the limiting frame through the clamping groove, and the welding wire conveying line is internally connected to one end of the welding head.

[0015] As a preferred solution of the present invention: the limit frame is movably connected to the outer surface of the clamping column through the limit slide on the inner surface, the transmission gear plate is meshed and connected with the rack at both ends of the arc frame, and the fastening screw is threadedly connected to the end of the first arc frame through a threaded hole.

[0016] A welding method of a metal pipe welding device for municipal construction, comprising:

[0017] Step 1: first put the welding device on one end of the metal pipe, then perform groove processing on the interfaces of the two sets of pipes, then butt the two sets of pipes, and then move the welding device to the position where welding is required;

[0018] Step 2: Align the welding heads at both ends of the welding component with the weld, rotate the threaded positioning rod to connect with the ground thread, so as to support the limiting component, and then rotate the positioning screws on the outer surfaces of the first arc frame and the second arc frame to contact the metal pipe, ensuring that the arc frame and the metal pipe maintain concentric circles, and then rotate and adjust the position of the welding head to reach the welding position close to the weld;

[0019] Step 3: Operate the controller to control the driving motor to drive the arc frame to rotate inside the annular slideway through the driving gear, and start feeding the welding wire into the welding head at the same time, so as to automatically weld the metal pipe in a 180-degree circular rotation. After welding is completed, control the arc frame to reset and rotate, and then rotate the fastening screw to separate it from the threaded hole, and then remove the welding device;

[0020] Step 4: While the welding head rotates with the arc frame, the transmission component rotates synchronously under the meshing connection with the rack. While the transmission component rotates, it drives the limit frame to slide back and forth through the clamping column, so that the welding head slides back and forth at the weld position, thereby reciprocating welding the weld to ensure the welding quality.

[0021] Beneficial effects of the present invention:

[0022] (1) The present invention arranges an arc frame inside the limiting component, so that when the arc frame rotates 180 degrees, two sets of welding heads can complete the circumferential welding of the pipeline, thereby improving the efficiency of pipeline welding and avoiding the need for workers to manually control the welding device to work. In addition, the limiting component is arranged outside the pipeline, which can provide a stable rotation track for the arc frame and reduce welding deviation. In addition, the threaded positioning rod can play a supporting role when the welding device is installed, thereby playing an auxiliary installation role.

[0023] (2) The present invention can automatically weld municipal metal pipes through the coordinated operation between the welding components and the limiting components, thereby reducing the labor intensity of workers and avoiding workers from performing welding work in harsh environments. At the same time, automatic welding can ensure welding efficiency and meet people's needs for the use of welding devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention will be further described below in conjunction with the accompanying drawings.

[0025] Figure 1 This is a schematic diagram of the structure of a metal pipe welding device for municipal construction;

[0026] Figure 2 It is a schematic diagram of the structure on the right side of the welding component;

[0027] Figure 3 It is a schematic diagram of the left side structure of the welding component;

[0028] Figure 4 for Figure 3 A schematic diagram of the partially enlarged structure at center A;

[0029] Figure 5 It is a schematic diagram of the transmission component structure;

[0030] Figure 6 It is a schematic diagram of the welding assembly structure;

[0031] Figure 7 It is a schematic diagram of the structure on the right side of the limiting component;

[0032] Figure 8 It is a schematic diagram of the left side structure of the limiting component;

[0033] Fig. 9 for Figure 7 Schematic diagram of the local enlarged structure at point B in the middle.

[0034] Description of the drawings: 1. welding component; 2. limiting component; 11. arc frame; 12. limiting slide; 13. welding wire conveying line; 14. power supply wire; 15. transmission tooth groove; 16. transmission assembly; 17. welding assembly; 18. limiting frame; 19. threaded rod; 110. cleaning block; 161. clamping column; 162. transmission gear disc; 163. limiting shaft; 171. welding head; 172. connection port; 173. limiting slide; 17 4. Card-joining groove; 175. Limiting frame; 176. Turning block; 21. Hinge; 22. First arc-shaped frame; 23. Gear rail; 24. Threaded hole; 25. Positioning screw; 26. Fastening screw; 27. Second arc-shaped frame; 28. Annular slide; 29. ​​Threaded positioning rod; 210. Connecting frame; 211. Driving gear; 212. Bevel gear shaft; 213. Bevel gear; 214. Driving motor; 215. Limiting column; 216. Controller. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. 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.

[0036] See also Figure 1-Figure 9 As shown, the present invention is a metal pipe welding device for municipal construction, comprising: a limiting component 2, in which a welding component 1 is rotatably installed;

[0037] The limiting component 2 includes a second arc frame 27, a connecting frame 210 is welded to the middle outer surface of the second arc frame 27, the bottom end of the second arc frame 27 is rotatably connected to the first arc frame 22, a threaded positioning rod 29 is threadedly connected to the top end of the connecting frame 210, a hinge 21 is provided at the connection between the second arc frame 27 and the bottom of the first arc frame 22, an annular slide 28 is provided between the second arc frame 27 and the first arc frame 22, and the outer surface edges of the second arc frame 27 and the first arc frame 22 are evenly and symmetrically threadedly connected with positioning screws 25;

[0038] The top of the first arc frame 22 is symmetrically provided with threaded holes 24, the top of the second arc frame 27 is symmetrically provided with fastening screws 26, the inner surfaces of the second arc frame 27 and the first arc frame 22 and located at the edge of the annular slideway 28 are provided with rack rails 23, and the inner surfaces of the second arc frame 27 and the first arc frame 22 located at one side of the annular slideway 28 are evenly provided with limiting columns 215;

[0039] A controller 216 is fixedly installed on the outer surface of one side of the connecting frame 210, a driving motor 214 is fixedly installed on the outer surface of one end of the connecting frame 210, a bevel gear shaft 212 is rotatably clamped on the middle edge of the second arc frame 27, one end of the bevel gear shaft 212 is fixedly connected to the driving gear 211, and one end of the driving motor 214 is fixedly connected to the bevel gear 213 meshing with the bevel gear shaft 212.

[0040] The welding component 1 includes an arc frame 11, a limiting slide groove 12 is provided on one side of the arc frame 11, a transmission tooth groove 15 is provided on the other side of the arc frame 11, and welding wire conveying lines 13 and power supply wires 14 are evenly arranged on the outer surfaces of both ends of the arc frame 11. 111 is fixedly installed on the outer surfaces of both ends of the arc frame 11, and the inner surfaces of the edges of both ends of the arc frame 11 are rotatably clamped with transmission components 16, one end of the transmission component 16 is movably connected to the welding component 17, and the inner surfaces of both ends of the arc frame 11 are symmetrically provided with limiting frames 18, and both ends of the arc frame 11 are threadedly connected with threaded rods 19, and one end of the threaded rods 19 is fixedly connected with a cleaning block 110.

[0041] The transmission assembly 16 includes a transmission gear plate 162 . A transmission gear plate 163 is fixedly connected to the center of one side of the transmission gear plate 162 . A clamping column 161 is provided at the edge of the other side of the transmission gear plate 162 .

[0042] The welding assembly 17 includes a limit frame 175, the outer surfaces of both ends of the limit frame 175 are provided with a clamping groove 174, the inner surface of the limit frame 175 is provided with a limit slide 173, the side center thread of the limit frame 175 is connected to a welding head 171, the outer surface of the welding head 171 is provided with a connecting port 172, and the outer surface of one end of the welding head 171 is provided with a rotating block 176.

[0043] The present invention arranges the arc frame 11 inside the limiting component 2, so that when the arc frame 11 rotates 180 degrees, the two sets of welding heads 171 can complete the circumferential welding of the pipeline, thereby improving the efficiency of pipeline welding and avoiding the manual control of the welding device by the staff. In addition, the limiting component 2 is arranged outside the pipeline, which can provide a stable rotation track for the arc frame 11 and reduce the welding deviation. In addition, the threaded positioning rod 29 can play a supporting role when the welding device is installed, thereby playing an auxiliary installation role.

[0044] The arc frame 11 of the present invention is internally rotatably engaged with the first arc frame 22 and the second arc frame 27 through the annular slide 28, which can limit the rotation of the arc frame 11. The limiting column 215 is slidably engaged with the outer surface of the arc frame 11 through the limiting slide groove 12, which can limit the arc frame 11 inside the annular slide 28 to prevent the arc frame 11 from rotating out of the annular slide 28. The driving gear 211 inside the second arc frame 27 is meshed and connected with the outer surface of the arc frame 11 through the transmission tooth groove 15, and can control the arc frame 11 to rotate forward and reverse inside the annular slide 28 through the driving gear 211 when the driving motor 214 is running.

[0045] The welding wire conveyor line 13 and the power supply conductor 14 of the present invention are fixedly connected to the welding head 171 through the connecting port 172, and can provide power for the welding head 171 and convey the welding wire. The limit frame 175 is slidably engaged with the limit frame 18 through the engaging groove 174, and can limit the reciprocating lateral sliding of the limit frame 175. The welding wire conveyor line 13 is internally connected to one end of the welding head 171 through 111, and 111 can convey the welding wire to ensure stable welding operation of the welding device.

[0046] The limiting frame 175 of the present invention is movably connected with the outer surface of the clamping column 161 through the limiting slide 173 on the inner surface, so when the transmission gear disc 162 rotates, it will drive the limiting frame 175 to slide back and forth through the clamping column 161, and the transmission gear disc 162 is meshed and connected with the rack 23 at both ends of the arc frame 11. When the arc frame 11 drives the transmission gear disc 162 to move inside the annular slide 28, the transmission gear disc 162 rotates under the meshing connection of the rack 23, thereby controlling the welding head 171 to perform reciprocating welding. The fastening screw 26 is threadedly connected to the end of the first arc frame 22 through the threaded hole 24, and can connect the first arc frame 22 and the second arc frame 27, thereby ensuring the stability of the operation of the limiting component 2.

[0047] A welding method of a metal pipe welding device for municipal construction, comprising:

[0048] Step 1: first put the welding device on one end of the metal pipe, then perform groove processing on the interfaces of the two sets of pipes, then butt the two sets of pipes, and then move the welding device to the position where welding is required;

[0049] Step 2: Align the welding heads 171 at both ends of the welding component 1 with the weld, rotate the threaded positioning rod 29 to connect with the ground thread, so as to support the limiting component 2, and then rotate the positioning screws 25 on the outer surfaces of the first arc frame 22 and the second arc frame 27 to contact the metal pipe, ensure that the arc frame 11 and the metal pipe maintain a concentric circle, and then rotate and adjust the position of the welding head 171 until it reaches the welding position close to the weld;

[0050] Step 3: The controller 216 controls the driving motor 214 to drive the arc frame 11 to rotate inside the annular slide 28 through the driving gear 211, and at the same time, the starter 111 is used to deliver the welding wire to the inside of the welding head 171, so as to automatically weld the metal pipe in a 180-degree circular rotation. After the welding is completed, the arc frame 11 is controlled to reset and rotate, and then the fastening screw 26 is rotated to separate from the threaded hole 24, and the welding device is removed.

[0051] Step 4, while the welding head 171 rotates with the arc frame 11, the transmission assembly 16 rotates synchronously under the meshing connection with the rack 23. While the transmission assembly 16 rotates, it will drive the limit frame 175 to slide back and forth through the clamping column 161, so that the welding head 171 slides back and forth at the weld position, thereby reciprocating welding the weld to ensure the welding quality.

[0052] The working principle of the present invention is as follows: during the municipal construction process, when welding connection is required between pipes, the welding device is firstly put on the outer surface of one end of the metal pipe as a whole, and then the interfaces of the two sets of pipes are grooved, and then the two sets of pipes are butt-jointed, and then the welding device is moved to the position where welding is required;

[0053] Ensure that the welding heads 171 at both ends of the arc frame 11 are aligned with the weld, then rotate the threaded positioning rod 29 to connect with the ground thread, so as to support the limiting component 2, and then rotate the positioning screws 25 on the outer surfaces of the first arc frame 22 and the second arc frame 27 to abut against the outer surfaces of the two groups of metal pipes, so as to position the welding device, and at the same time, calibrate and limit the two groups of pipes, so that the welding device and the pipes remain concentric, and then rotate the rotating block 176 to drive the welding head 171 thread to extend until the end of the welding head 171 reaches the welding position between the pipes;

[0054] Then, the controller 216 is operated to control the driving motor 214 to drive the bevel gear shaft 212 to rotate synchronously through the bevel gear 213, and the bevel gear shaft 212 will synchronize the driving gear 211 at one end to rotate inside the annular slide 28, so that the rotating driving gear 211 drives the meshing arc frame 11 to rotate inside the annular slide 28. At the same time, the starter 111 is used to transport welding wire to the energized welding head 171, so that the welding head 171 melts the welding wire to weld the weld between the two groups of pipes. Therefore, as the arc frame 11 rotates, the two groups of welding heads 171 will be driven to perform a 180-degree circular rotation and automatic welding on the metal pipes. While the welding head 171 rotates with the arc frame 11, the transmission assembly 16 is meshed with the rack 23. The transmission assembly 16 rotates synchronously, and the limit frame 175 is driven to slide back and forth through the clamping column 161 while the transmission assembly 16 rotates, so that the welding head 171 slides back and forth at the weld position, thereby performing reciprocating welding on the weld to ensure the welding quality. After the welding is completed, the driving motor 214 is controlled to run in the reverse direction, thereby driving the arc frame 11 to reset and rotate, and finally the fastening screw 26 is rotated to separate the threaded hole 24, and the welding device can be removed. Therefore, through the coordinated operation between the welding component 1 and the limit component 2, the municipal metal pipe can be automatically welded, which reduces the labor intensity of the staff and avoids the staff from performing welding work in harsh environments. At the same time, automatic welding can ensure welding efficiency and meet people's demand for the use of welding devices.

[0055] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A metal pipe welding device for municipal construction, comprising: A limiting component (2), wherein a welding component (1) is rotatably mounted inside the limiting component (2); The limiting component (2) comprises a second arc frame (27), a connecting frame (210) is welded on the middle outer surface of the second arc frame (27), the bottom end of the second arc frame (27) is rotatably connected to the first arc frame (22), a threaded positioning rod (29) is threadedly connected to the top end of the connecting frame (210), a hinge (21) is provided at the connection between the second arc frame (27) and the bottom of the first arc frame (22), an annular slideway (28) is provided between the second arc frame (27) and the first arc frame (22), and the outer surface edges of the second arc frame (27) and the first arc frame (22) are evenly and symmetrically threadedly connected with positioning screws (25); The top of the first arc frame (22) is symmetrically provided with threaded holes (24), the top of the second arc frame (27) is symmetrically provided with fastening screws (26), the inner surfaces of the second arc frame (27) and the first arc frame (22) and located at the edge of the annular slideway (28) are provided with gear rails (23), and the inner surfaces of the second arc frame (27) and the first arc frame (22) and located at one side of the annular slideway (28) are evenly provided with limiting columns (215); A controller (216) is fixedly mounted on the outer surface of one side of the connecting frame (210), a driving motor (214) is fixedly mounted on the outer surface of one end of the connecting frame (210), a bevel gear shaft (212) is rotatably engaged with the middle edge of the second arc-shaped frame (27), one end of the bevel gear shaft (212) is fixedly connected to a driving gear (211), and one end of the driving motor (214) is fixedly connected to a bevel gear (213) meshingly connected to the bevel gear shaft (212).

2. A metal pipe welding device for municipal construction according to claim 1, characterized in that: The welding component (1) comprises an arc frame (11), a limiting slide groove (12) is provided on one side of the arc frame (11), a transmission tooth groove (15) is provided on the other side of the arc frame (11), welding wire conveying lines (13) and power supply wires (14) are evenly arranged on the outer surfaces of both ends of the arc frame (11), and (111) is fixedly installed on the outer surfaces of both ends of the arc frame (11); The inner surfaces of both ends of the arc frame (11) are rotatably connected with a transmission assembly (16), one end of the transmission assembly (16) is movably connected with a welding assembly (17), and the inner surfaces of both ends of the arc frame (11) are symmetrically provided with a limited position frame (18), both ends of the arc frame (11) are threadedly connected with a threaded rod (19), and one end of the threaded rod (19) is fixedly connected with a cleaning block (110).

3. A metal pipe welding device for municipal construction according to claim 2, characterized in that: The transmission assembly (16) comprises a transmission gear disc (162), a transmission gear disc (163) is fixedly connected to the center of one side of the transmission gear disc (162), and a clamping column (161) is provided on the edge of the other side of the transmission gear disc (162).

4. A metal pipe welding device for municipal construction according to claim 3, characterized in that: The welding assembly (17) comprises a limit frame (175), the outer surfaces of both ends of the limit frame (175) are provided with clamping grooves (174), the inner surface of the limit frame (175) is provided with a limit slideway (173), the side center of the limit frame (175) is threadedly connected to a welding head (171), the outer surface of the welding head (171) is provided with a connecting port (172), and the outer surface of one end of the welding head (171) is provided with a rotating block (176).

5. A metal pipe welding device for municipal construction according to claim 4, characterized in that: The arc frame (11) is rotatably connected to the inside of the first arc frame (22) and the second arc frame (27) through an annular slideway (28); the limiting column (215) is slidably connected to the outer surface of the arc frame (11) through a limiting slide groove (12); and the driving gear (211) inside the second arc frame (27) is meshedly connected to the outer surface of the arc frame (11) through a transmission tooth groove (15).

6. A metal pipe welding device for municipal construction according to claim 5, characterized in that: The welding wire conveying line (13) and the power supply wire (14) are fixedly connected to the welding head (171) via a connecting port (172); the limiting frame (175) is slidably engaged with the limiting frame (18) via an engaging groove (174); and the welding wire conveying line (13) is internally connected to one end of the welding head (171) via (111).

7. A metal pipe welding device for municipal construction according to claim 6, characterized in that: The limiting frame (175) is movably connected to the outer surface of the clamping column (161) through the limiting slideway (173) on the inner surface, the driving gear plate (162) is meshed and connected with the gear rail (23) at both ends of the arc frame (11), and the fastening screw (26) is threadedly connected to the end of the first arc frame (22) through the threaded hole (24).

8. A metal pipe welding device for municipal construction and a welding method thereof, using the metal pipe welding device for municipal construction as claimed in claim 7, characterized in that: include: Step 1: first put the welding device on one end of the metal pipe, then perform groove processing on the interfaces of the two sets of pipes, then butt the two sets of pipes, and then move the welding device to the position where welding is required; Step 2: align the welding heads (171) at both ends of the welding component (1) with the weld, rotate the threaded positioning rod (29) to connect with the ground thread, so as to support the limiting component (2), and then rotate the positioning screws (25) on the outer surfaces of the first arc frame (22) and the second arc frame (27) to contact with the metal pipe, ensure that the arc frame (11) and the metal pipe maintain concentric circles, and then rotate and adjust the position of the welding head (171) to reach the welding position close to the weld; Step 3: The operation controller (216) controls the driving motor (214) to drive the arc frame (11) to rotate inside the annular slideway (28) through the driving gear (211), and at the same time, the starter (111) delivers the welding wire to the inside of the welding head (171), thereby automatically welding the metal pipe in a 180-degree circular rotation. After the welding is completed, the arc frame (11) is controlled to reset and rotate, and then the fastening screw (26) is rotated to separate from the threaded hole (24), and the welding device is removed; Step 4, wherein, while the welding head (171) rotates following the arc frame (11), the transmission assembly (16) rotates synchronously under the meshing connection with the rack (23). While the transmission assembly (16) rotates, the limit frame (175) is driven to slide back and forth through the clamping column (161), so that the welding head (171) slides back and forth at the weld position, thereby reciprocating welding the weld to ensure the welding quality.

Images