CN116810235A - Non-notch steel pipe welding equipment and welding process - Google Patents

Abstract

The application provides a welding device and a welding process for a seamless steel tube, wherein the welding device comprises a steel tube bracket, a frame, an outer welding machine head, a rotating device and an inner welding assembly, wherein a plurality of steel tube brackets are transversely and coaxially arranged on a base at intervals, the plurality of steel tube brackets jointly support the steel tube, the steel tube can transversely and coaxially reciprocate at the upper end of the steel tube bracket, the frame is arranged at one side of the steel tube bracket, and the outer welding machine head is arranged at one side of the frame facing the steel tube bracket in a cantilever manner; a long shaft rod is coaxially arranged above the steel pipe brackets, an inner welding machine component is arranged at the end part of the supporting rod, rotating devices are arranged between the steel pipe brackets at intervals, and a pipe outer clamping mechanism is arranged on the frame. The technical scheme adopts an inner and outer double-side welding process to manufacture the welded steel pipe, and the full-automatic welding arrangement ensures that the welding seams inside and outside the steel pipe reach a smooth and intact welding surface result, and the welding seam effect inside the steel pipe is same smooth and consistent with the welding seam effect outside the steel pipe.

Description

Notchless steel pipe welding equipment and welding process

Technical field

This application belongs to the field of mechanical processing, relates to steel pipe processing, and in particular relates to a notch-less steel pipe welding equipment and welding process.

Background technique

The preparation method of the welded steel pipe is to bend the steel plate or steel strip into a tubular shape and perform welding to obtain the welded steel pipe. The search found the following published patent, the manufacturing method of welded steel pipe (CN1050556C), which consists of the following steps: supply high-frequency current to both ends of the steel strip, and preheat the two ends to a temperature below the melting point of the steel strip; The extrusion roller presses the two ends to form a butt portion including a butt seam; near the extrusion point, a high-density energy beam capable of melting the entire thickness of the steel strip is irradiated to weld the two ends; This squeeze roll pressurizes with a pressurizing amount sufficient to prevent welding defects.

Existing steel pipe products are usually processed by external welding machines. However, the existing steel pipe processing methods have inconsistent weld quality. Especially for steel pipes with larger wall thickness and larger size, welds are prone to appear. Problems with discontinuities or end gaps affect the quality of the final steel pipe product.

Contents of the invention

In order to effectively solve the above problems, this application provides a notch-free steel pipe welding process with simple structure, reasonable design, convenient operation, stable and reliable.

A kind of unnotched steel pipe welding equipment, which is characterized in that it includes a steel pipe bracket, a frame, an external welding head, a rotating device and an internal welding component. A plurality of steel pipe brackets are installed transversely and coaxially spaced on the base. Two steel pipe brackets jointly support the steel pipe. The steel pipe can be transversely coaxially reciprocated at the upper end of the steel pipe bracket. A rack is installed on one side of the steel pipe bracket. The rack is cantilevered toward the side of the steel pipe bracket with an external welding head and Pipe external clamping mechanism; a long shaft rod is coaxially installed above the steel pipe bracket, an internal welding machine assembly is installed at the end of the long shaft rod, and multiple rotating devices are arranged at intervals between the steel pipe brackets.

By adopting the above technical solution, an integrated machine with internal welding and external welding is used to process the steel pipe. First, the steel pipe is positioned and set, and the external welding machine head performs the first welding process on the steel pipe from the outside of the steel pipe. After completion, the rotating device drives the steel pipe to flip over and dock it. Turn the seam downward, then open the internal welding assembly to weld the butt joint inside the steel pipe for the second time, so as to perform external and internal double-sided welding of the butt joint of the steel pipe, so that the weld can maintain good performance both inside and outside. The secondary welding compensates for the possible gaps in the first welding and solves the problem of possible gaps in the weld.

The use of multiple coaxial steel pipe brackets can realize the axial movement of the steel pipe, and the use of a rotating device to realize the coaxial rotation of the steel pipe, and cooperate with the processing technology of the welding machine to accurately control the movement of the steel pipe.

Moreover, the steel pipe bracket includes a fixed bracket, a shaft roller and a shaft roller motor. The two fixed brackets are symmetrically fixed on the base. A shaft roller is installed between the fixed brackets on both sides. The center diameter of the shaft roller is small. The side structure has a symmetrical conical structure that increases outward. The two ends of the shaft roller are equipped with support shafts that are rotated and installed in the fixed bracket. The support shaft at one end is connected to the shaft roller motor.

By adopting the above technical solution, the steel pipe bracket can effectively support the steel pipe, and can be processed with a variety of steel pipes of different specifications and diameters. The rotation of the shaft roller can drive the movement of the steel pipe, and the multiple shaft rollers move synchronously to ensure stable and reliable movement of the steel pipe.

Moreover, the main frame of the external welding head is set on the frame above the base, and the frame guide is set on the transverse track. The frame drives the external welding head to reciprocate along the axial direction of the steel pipe. The lower part of the main frame of the external welding head is installed. There is an external welding gun, and a material spreading pipe is installed on one side of the external welding gun. A recovery pipe is also installed on the main frame of the external welding head. The tail of the recovery pipe is connected to the solder recovery device through a pipeline. The nozzle of the recovery pipe is set at One side of the welding gun and set at intervals.

By adopting the above technical solution, the external welding head moves linearly with the frame, and multiple welding guns can be set up to improve welding efficiency and ensure the quality of steel pipe welding. The recycling structure can recover the remaining solder and reuse it, saving costs.

Moreover, the internal welding machine assembly includes an internal welding gun, a guide wheel and an internal solder recovery pipe. The internal welding gun is installed at the end of a long shaft. A plurality of guide wheels with brackets are installed on the long shaft on one side of the internal welding gun. , the guide wheel is supported on the inner wall of the steel pipe.

By adopting the above technical solution, it is ensured that the work of the internal welding gun can be carried out stably and reliably, and the coaxiality of the welding seam in the pipe is ensured.

Moreover, an internal solder recovery pipe is installed on one side of the internal welding gun. The nozzle of the internal solder recovery pipe is spaced apart from the internal welding gun and is connected to the solder recovery device through a pipeline.

By adopting the above technical solution, the remaining solder on the steel pipe after internal welding can be recovered and recycled again, thus saving the amount of flux used.

Moreover, the outer pipe clamping mechanism includes a hanger, a clamping cylinder, a fixed frame, a connecting rod, a clamp arm, and a steel brush pressure head. The hanger is installed on the frame, and a clamping oil cylinder is installed on both sides of the lower end of the hanger. , the lower end of the piston rod of the clamping cylinder has two clamping arms hinged relative to each other. The lower part of the clamping arm is equipped with a steel brush pressure head. A fixing frame is installed in the middle of the lower end of the hanger. Two connecting rods are hinged relative to the fixed frame. The two connecting rods are hinged relative to each other. The other end of the rod is hinged in the middle of the clamp arm; the piston rod of the clamping cylinder moves up and down, driving the clamp arm to swing to clamp or loosen the steel pipe.

By adopting the above technical solution, the clamping angle between the clamping arms can be adjusted according to the diameter of the steel pipe, thereby controlling the arc of the steel pipe according to the size of the steel pipe, and can be adjusted up and down to provide adjustable pressure to further ensure the quality of steel pipe welding.

Moreover, the rotating device includes a screw bracket, a screw, a turntable bracket, a turntable and a jacket. The screw bracket is fixed on the base on both sides of the steel pipe in the radial direction. The screw bracket is horizontally installed with a screw, and two turntable brackets are installed on the screw in a symmetrical meshing manner. , the two turntable brackets are made with reverse internal threads, and the rotation of the screw can drive the two turntable brackets to move in the opposite direction; a turntable is installed on the turntable bracket respectively, and an annular jacket is set on the outer circumference of the turntable.

By adopting the above technical solution, the steel pipe can be rotated in its original position. Multiple rotating devices jointly drive the steel pipe to rotate, and the rotation speed is stable and reliable.

Moreover, multiple sets of one-to-one corresponding clamping rods are symmetrically arranged on both sides of the steel pipe in the radial direction, and the spacing between the clamping rods can be adjusted.

By adopting the above technical solution, the position of the steel pipe can be limited from both sides, and the circumferential shape of the steel pipe can be fully controlled by cooperating with the pressure from above by the clamping mechanism outside the pipe and the included angle limit.

A notch-less steel pipe welding process is characterized by adopting the following steps:

1. Bend the steel strip into a tubular steel pipe main body. The two sides of the steel strip meet to form a butt joint. The steel pipe main body is placed on the steel pipe bracket with the butt joint above;

2. Set multiple sets of clamping rods on both radial sides of the steel pipe main body to limit and fix the butt joints. An extension plate is welded and fixed at both ends of the butt joints. The extension plates are simultaneously connected to the sides of the steel pipe main body on both sides of the butt joints. ;

(3) Lay the welding material on the butt joint of the steel pipe body, and extend the solder to the extension plates at both ends. The external welding head performs linear welding along the butt joint from one end of the steel pipe body to the other end of the steel pipe body. The welding seam Both ends are extended to the extension plate; during the external welding process, the outer clamping mechanism of the pipe is pressed down and close to the outer wall of the main body of the steel pipe;

(4) After completing the external welding, loosen the clamping rod, and the rotating device drives the steel pipe main body to rotate coaxially, rotate the butt joint directly downward, and align it with the internal welding component. Then, the steel pipe bracket drives the steel pipe main body to move axially. The internal welding gun performs linear welding inside the steel pipe body along the butt joint, and both ends of the welding seam extend to the extension plate;

(5) After the internal welding is completed, use a laser cutting machine to cut and remove the extension plates at both ends of the steel pipe body.

Using the above technical solution, during the processing, the welding machine is moved during external welding and the steel pipe remains stationary to ensure that the shape of the steel pipe reaches the preset arc for the first welding; during internal welding, the process is to move the steel pipe axially, and the steel pipe is moved internally. The welding head does not move to prevent the internal welding machine from moving away from the straight line of the butt joint. This is also because the steel pipe has better stability after the first external welding process, and axial movement will not cause deformation of the steel pipe.

Moreover, during step (4), before internal welding starts, adjust the rotating device to loosen the steel pipe;

At the same time as the internal welding is being processed, the outer clamping mechanism of the pipe is pressed down and close to the main body of the steel pipe.

By adopting the above technical solution, the friction force of the rotating mechanism on the steel pipe can be reduced, which facilitates the linear movement of the steel pipe;

By adopting the above technical solution, multiple external pipe clamping mechanisms effectively assist in supporting the steel pipe and clamp the steel pipe from both sides above to ensure that the shape of the steel pipe remains unchanged and prevent the steel pipe from deforming.

To sum up, this application includes at least one of the following beneficial technical effects:

1. This technical solution uses internal and external double-sided welding processes to produce welded steel pipes. The fully automatic welding setting ensures that the internal and external welds of the steel pipe achieve a flat and intact welding surface. The internal and external welds of the steel pipe are equally smooth and consistent. , no leaks or pits.

2. This device is equipped with an integral limiting device, and the welding position is equipped with a subsequent limiting device to further ensure the concentricity of the two side plates after the steel pipe is connected at the welding position.

3. During welding, the steel pipes at both ends of the weld are added with extension plates, which play the role of end positioning, and the internal and external welding lines will extend to the extension plates to ensure that there are no gaps at the ends and improve the quality of the welded steel pipe products. After processing by this method, For steel pipes, only the excess extension plates need to be cut, and the entire length of the steel pipe can be retained. The operation is simple and the processing efficiency is improved.

Description of the drawings

Figure 1 is a schematic diagram of the overall structure of the welding device.

Figure 2 is a schematic diagram of the axial structure of the steel pipe.

Figure 3 is a schematic diagram of the rotating device.

Figure 4 is a schematic diagram of the structure of the external welding head.

Figure 5 is a schematic diagram of the clamp rod limit.

Reference signs: 1. Steel pipe; 2. Long shaft; 3. Frame; 4. Pipe external clamping mechanism; 5. External welding head; 6. Steel pipe bracket; 7. Rotating device; 8. Clamping rod; 9. Internal solder recovery pipe; 10. Internal welding gun; 11. Guide wheel; 101. Steel pipe body; 102. Butt joint; 103. Extension plate; 401. Hanger; 402. Clamping cylinder; 403. Fixed frame; 404 , connecting rod; 405, clamping arm; 406, steel brush pressure head; 501, recovery pipe; 502, external welding head main frame; 503, spreading pipe; 504, external welding gun; 601, shaft roller; 602, fixed bracket ; 603. Shaft roller motor; 701. Jacket; 702. Turntable; 703. Rotating motor; 704. Turntable bracket; 705. Screw; 706. Screw bracket.

Detailed ways

The present application will be further described in detail below in conjunction with the accompanying drawings.

A kind of non-notch steel pipe welding equipment, including a steel pipe bracket 6, a frame 3, an external welding head 5, a rotating device 7 and an internal welding component. A plurality of steel pipe brackets 6 are installed at horizontal and coaxial intervals on the base. The steel pipe The structure of the bracket 6 is shown in Figure 2. The steel pipe bracket 6 includes a fixed bracket 602, a shaft roller 601 and a shaft roller motor 603. The two fixed brackets 602 are symmetrically fixed on the base. The fixed brackets 602 on both sides A shaft roller 601 is installed between them. The center diameter of the shaft roller 601 is small, and both sides are formed with symmetrical conical structures that increase outward. The two ends of the shaft roller 601 are equipped with support shafts and are rotated and installed in a fixed bracket. One section of the shaft roller 601 is The support shaft is connected to the shaft roller motor 603, and the shaft roller motor 603 can drive the shaft roller 601 to rotate to drive the steel pipe to move axially.

The plurality of steel pipe brackets jointly support the steel pipe 1. The steel pipe 1 can be transversely coaxially reciprocated at the upper end of the steel pipe bracket. A frame 3 is installed on one side of the steel pipe bracket. The frame 3 is cantilevered toward the side of the steel pipe bracket 6. An external welding head 5 is installed; the external welding head 5 includes an external welding head main frame 502, an external welding gun 504 and a material spreading pipe 503. The external welding head main frame 502 is arranged on the frame 3 above the base. The frame 3. The guide is set on a transverse track, which is parallel to the axial direction of the steel pipe. The frame can drive the external welding head to move back and forth laterally; three external welding guns 504 are installed at the lower part of the main frame 502 of the external welding head, and the external welding guns 504 are respectively connected with welding wires. The reels supply welding wire simultaneously; the gun heads of the three external welding guns 504 are all concentrated toward the middle, and the processing positions of the welding guns are concentrated at the same intersection to ensure welding quality; in order to improve safety, protective boxes are installed outside the three welding guns 504 to protect A spreading pipe 503 is also installed on one side of the box to spread flux simultaneously during welding. A recovery pipe 501 is also installed on the main frame 502 of the external welding head. The tail end of the recovery pipe 501 is connected to a solder recovery device through a pipeline. The nozzle of the recovery pipe is set on the side of the welding gun and is spaced apart. After use, it is inhaled through negative pressure. The remaining flux can be recycled.

A long shaft rod 2 is coaxially installed above the steel pipe bracket. An internal welding machine assembly is installed at the end of the long shaft rod 2. The internal welding machine assembly includes an internal welding gun 10, a guide wheel 11 and an internal solder recovery pipe 9. The internal welding gun 10 is installed At the end of the long shaft 2, there are two internal welding guns 10 with the gun heads facing a point concentrated on the butt joint of the steel pipe. A plurality of guide wheels 11 with brackets are installed on one side of the internal welding gun 10. The guide wheels support The inner wall of the steel pipe supports the internal welding gun welding and ensures flexible and resistance-free movement with the steel pipe; an internal solder recovery pipe 9 is installed on one side of the internal welding gun 10, and the nozzle of the internal solder recovery pipe 9 is spaced apart from the internal welding gun 10. The pipeline is connected to the solder recovery device.

Multiple sets of pipe outer clamping mechanisms 4 are installed on the frame. When the internal welding machine assembly is working, the pipe outer clamping mechanism 4 is pressed down to clamp the steel pipe and keep the steel pipe butt joints aligned. The pipe outer clamping mechanism 4 includes a hanger. 401. Clamping cylinder 402, fixed frame 403, connecting rod 404, clamping arm 405, steel brush pressure head 406, hanger 401 is installed on the frame 3, and a clamping cylinder 402 is installed on both sides of the lower end of the hanger 401. Two clamping arms 405 are hinged to the lower end of the piston rod of the clamping cylinder 402, and a steel brush pressure head 406 is installed at the lower part of the clamping arm 405; a fixing frame 403 is installed in the middle of the lower end of the hanger 401, and two connecting rods are hinged to the fixing frame 403 to face each other. 404, the other ends of the two connecting rods 404 are respectively hinged in the middle of the clamp arm 405; the piston rod of the clamping cylinder 402 moves up and down, driving the clamp arm 405 to swing to clamp or loosen the steel pipe 1. The steel brush pressure head 406 presses the outer wall of the steel pipe 1 to maintain the arc of the steel pipe 1 without causing too much friction to prevent damage to the steel pipe 1.

A plurality of rotating devices 7 are arranged at intervals between the steel pipe brackets 6, and the rotating devices 7 can drive the steel pipes to rotate coaxially. The rotating device 7 includes a screw bracket 706, a screw 705, a turntable bracket 704, a turntable 702, and a rotating motor 703. The screw bracket 706 is fixed on the base on both radial sides of the steel pipe 1. The screw bracket 706 is horizontally installed with a screw 705. The screw 705 Two turntable brackets 704 are installed on the upper symmetrical meshing drive. The two turntable brackets 704 are made with reverse internal threads. The rotation of the screw can drive the two turntable brackets to move in the opposite direction, and synchronously clamp or loosen the steel pipe; the turntable brackets 704 are respectively equipped with turntables. 702. The rotating shaft of each turntable 702 is drivingly connected to a rotating motor 703. The rotating motor drives the turntable to rotate, thereby driving the steel pipe 1 to rotate.

An annular jacket 701 is placed on the outer circumference of the turntable 702 to increase the friction between the turntable and the outer wall of the steel pipe.

Multiple sets of one-to-one corresponding clamping rods 8 are symmetrically arranged on both sides of the steel pipe 1 in the radial direction. The distance between the clamping rods 8 can be adjusted. The clamping rods 8 are arranged vertically to limit the position of the steel pipe 1 from both sides to prevent the alignment of the tubular steel strips. The sides spread out to both sides.

A notchless steel pipe welding process using the following steps:

3. Bend the steel strip into a tubular steel pipe main body 101, and the two sides of the steel strip are connected to form a butt joint 102. The steel pipe main body 101 is placed on the steel pipe bracket, and the butt joint 102 is located above;

4. Set multiple sets of clamping rods 8 on both radial sides of the steel pipe body 101 to limit and fix the butt joints. An extension plate 103 is welded and fixed at both ends of the butt joints 102. The extension plates 103 are connected to the butt joints 102 at the same time. The sides of the tubular steel strips on both sides further lock the end butt position of the steel pipe body 101 to extend the weld processing length;

(3) External welding, lay solder on the butt joint 102 of the steel pipe main body 101, and extend the solder to the extension plates 103 at both ends. The external welding head 5 moves along the butt joint 102 from one end of the steel pipe main body 101 to the steel pipe. The other end of the main body 101 moves linearly and is welded. The steel pipe main body 101 is welded into a round pipe, and both ends of the weld are extended to the extension plate;

At the same time, the solder recovery device recovers the remaining solder on the steel pipe body 101 after welding and sends it to the recovery bin to wait for recycling;

At the same time, the pipe outer clamping mechanism 4 presses down and is close to the outer wall of the steel pipe body 101 to ensure the arc of the steel pipe;

(4) After completing the external welding, loosen the clamping rod, and the rotating device 7 drives the steel pipe body 101 to rotate coaxially, rotate the butt joint 102 directly downward, and align it with the internal welding component; then open the internal welding component and open the steel pipe at the same time The bracket 6 drives the steel pipe 1 to move axially, cooperates with the internal welding assembly, and performs linear welding inside the steel pipe body 101 along the butt joint 102, so that there are no leakage points in the internal weld of the steel pipe, ensuring the welding quality of the steel pipe, and both ends of the weld extend. to the extension board;

During this process, the remaining solder after internal soldering components are synchronously recycled and sent to the recycling bin through pipelines to wait for recycling;

During this process, the outer pipe clamping mechanism 4 presses down and is close to the outer wall of the steel pipe body 101 to ensure the arc of the steel pipe.

During this process, adjust the clamping rod 8 again to fix the steel pipe, and adjust the rotating device to loosen the steel pipe to reduce the frictional resistance to the steel pipe;

(5) After the internal welding is completed, wait for the steel pipe to cool, and manually use a laser cutting machine to cut and remove the extension plates 103 at both ends of the round pipe.

There is no fixed requirement for the size of the extension plate 103, as long as the support effect for the solder is ensured. The extension plate has a curvature similar to that of the round pipe, and the welding height is flush with the outer surface of the butt joint.

When moving the welding machine for external welding, the steel pipe remains stationary to ensure that the shape of the steel pipe reaches the preset arc for the first welding. During the internal welding process, the steel pipe is moved axially and the internal welding components do not move. This is due to the lack of effective positioning support for the internal welding machine. Prevent the internal welding machine from moving away from the straight line of the butt joint.

The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application shall be covered by the scope of protection of the present application. Inside.

Claims (10)

1. A kind of unnotched steel pipe welding equipment, characterized by: including a steel pipe bracket (6), a frame (3), an external welding head (5), a rotating device (7) and an internal welding component, on a base A plurality of steel pipe brackets (6) are installed at horizontal and coaxial intervals. The plurality of steel pipe brackets (6) jointly support the steel pipe (1). The steel pipe (1) can be transversely coaxially reciprocated at the upper end of the steel pipe bracket (6). A frame (3) is installed on one side of the steel pipe bracket (6), and an external welding head (5) and a pipe external clamping mechanism (5) are cantilevered on the side of the frame (3) facing the steel pipe bracket (6). 4); Install the long shaft rod (2) coaxially above the steel pipe bracket (6), install the internal welding machine assembly at the end of the long shaft rod (2), and set multiple intervals between the steel pipe brackets (6) A rotating device (7). 2. The notch-free steel pipe welding equipment according to claim 1, characterized in that: the steel pipe bracket (6) includes a fixed bracket (602), a shaft roller (601) and a shaft roller motor (603), two fixed The bracket (602) is symmetrically fixed on the base, and a shaft roller (601) is installed between the fixed brackets (602) on both sides. The center diameter of the shaft roller (601) is small, and there are symmetrical holes on both sides that increase outward. It has a conical structure, and the two ends of the shaft roller (601) are equipped with support shafts to rotate and be installed in the fixed bracket (602). The support shaft at one end is connected to the shaft roller motor (603). 3. The notch-free steel pipe welding equipment according to claim 1, characterized in that: the external welding head (5) includes an external welding head main frame (502), an external welding gun (504), and a spreading pipe (503 ) and the recovery pipe (501), the main frame of the external welding head (502) is set on the frame (3) above the base, the guide of the frame (3) is set on the transverse rail, the main frame of the external welding head (502) An external welding gun (504) is installed at the lower part. A spreading pipe (503) is also installed on one side of the external welding gun (504). A recovery pipe (501) is also installed on the main frame of the external welding head (502). The recovery pipe (501) The tube tail of 501) is connected to the solder recovery device through a pipeline, and the nozzle of the recovery tube (501) is arranged on one side of the external welding gun (504) and is arranged at intervals. 4. The notch-free steel pipe welding equipment according to claim 1, characterized in that: the internal welding machine assembly includes an internal welding gun (10), a guide wheel (11) and an internal solder recovery pipe (501), and the internal welding gun (10) ) is installed at the end of the long shaft (2). A plurality of guide wheels (11) with brackets are installed on the long shaft (2) on the side of the internal welding gun (10). The guide wheels (11) are supported on the steel pipe. (1) Inner wall. 5. The notch-free steel pipe welding equipment according to claim 4, characterized in that: an internal solder recovery pipe (9) is installed on one side of the internal welding gun, and the nozzle of the internal solder recovery pipe (9) is in contact with the internal welding gun (10). The intervals are set up and connected to the solder recovery device through pipelines. 6. The notch-free steel pipe welding equipment according to claim 1, characterized in that: the pipe outer clamping mechanism (4) includes a hanger (401), a clamping cylinder (402), a fixed frame (403), and a connecting rod. Rod (404), clamping arm (405), steel brush pressure head (406), hanger (401) are installed on the frame (3), and a clamping cylinder (402) is installed on both sides of the lower end of the hanger (401) , the lower end of the piston rod of the clamping cylinder (402) is hinged with two clamping arms (405) relative to each other. A steel brush pressure head (406) is installed at the lower part of the clamping arm (405), and a fixing frame is installed in the middle of the lower end of the hanger (401). (403), the fixed frame (403) is hinged with two connecting rods (404) relative to each other, and the other ends of the two connecting rods (404) are respectively hinged with the middle part of the clamping arm (405); the piston of the clamping cylinder (402) is The rod moves up and down, driving the clamping arm (405) to swing to clamp or loosen the steel pipe (1). 7. The notch-free steel pipe welding equipment according to claim 1, characterized in that: the rotating device (7) includes a screw bracket (706), a screw (705), a turntable bracket (704), a turntable (702) and a jacket. (701), the screw bracket (706) is fixed on the base on both radial sides of the steel pipe (1), the screw bracket (706) is horizontally installed with a screw rod (705), and two turntable brackets are installed on the screw rod (705) for symmetrical meshing and driving (704), the two turntable brackets (704) are made with reverse internal threads, and the rotation of the screw (705) can drive the two turntable brackets (704) to move in the opposite direction; the turntable brackets (704) are respectively equipped with turntables (702), An annular jacket (701) is placed on the outer circumference of the turntable (702). 8. The notch-free steel pipe welding equipment according to claim 1, characterized in that: there are multiple sets of one-to-one corresponding clamping rods (8) symmetrically arranged on both sides of the steel pipe (1) in the radial direction, and between the clamping rods (8) The spacing can be adjusted. 9. A notch-free steel pipe welding process, characterized by adopting the following steps: The steel strip is bent into a tubular steel pipe main body (101), and the two sides of the steel strip are connected to form a butt joint (102). The steel pipe main body (101) is placed on the steel pipe bracket 6, and the butt joint (102) is located above; above Multiple sets of clamping rods (8) are provided on both radial sides of the steel pipe main body (101) to limit and fix the butt joint (102). An extension plate (103) is welded and fixed at both ends of the butt joint (102). The extension plate (103) simultaneously connects the sides of the steel pipe main body (101) on both sides of the butt joint (102); (3) Lay solder on the butt joint (102) of the steel pipe body (101), extend the solder to the extension plates (103) at both ends, and install the external welding head (5) along the butt joint (102) Move linearly from one end of the steel pipe main body (101) to the other end of the steel pipe main body (101), and perform welding. The steel pipe main body (101) is welded into a round pipe, and both ends of the weld are extended to the extension plate (103); The pipe outer clamping mechanism (4) presses down and is close to the outer wall of the steel pipe main body (101); (4) After completing the external welding, loosen the clamping rod, and the rotating device (7) drives the steel pipe body to rotate coaxially, rotate the butt joint (102) directly downward, and align it with the internal welding component. Then, the steel pipe bracket (102) 6) Drive the steel pipe main body (101) to move axially, and the internal welding gun performs linear welding inside the steel pipe main body (101) along the butt joint (102), and both ends of the welding seam extend to the extension plate (103); (5) After the internal welding is completed, use a laser cutting machine to cut and remove the extension plates (103) at both ends of the steel pipe main body (101). 10. The notch-free steel pipe welding process according to claim 9, characterized in that: during step (4), before starting internal welding, adjust the rotating device (7) to loosen the steel pipe (1); At the same time as the internal welding is being performed, the outer pipe clamping mechanism (4) presses down and is close to the outer wall of the steel pipe main body (101).