Reducing circumferential automatic internal welding construction process

Abstract

The invention relates to the technical field of pipeline welding, in particular to a variable-diameter annular automatic inner welding construction process. The construction technology comprises the following steps that a thick pipe, a taper pipe and a thin pipe are in butt joint, a variable-diameter annular automatic inner welding machine is placed in the thick pipe to move to a welding position, the direction of a driving wheel set is adjusted, so that driving wheel sets of driving mechanisms on the two sides of the variable-diameter annular automatic inner welding machine deflect by the same angle in the same side direction, the deflection angle of the driving wheel sets is smaller than 90 degrees, and welding is completed. Then a driving wheel set is started to rotate relative to a limiting mechanism so as to drive the driving mechanisms on the two sides and the welding mechanism to rotate in the thin pipe and the thick pipe in the circumferential direction correspondingly, and the first inner seam and the second inner seam are welded through the welding mechanism in the rotating process of the driving mechanisms; and performing external welding by using an external welding machine. The height of the welding gun can be adjusted, the distance between the welding gun and an inner seam can be guaranteed when the inner seam between the reducer union and a thick pipe and the inner seam between the reducer union and a thin pipe are welded, and then the inner seams with different diameters between the reducer union and the thick pipe and the inner seam between the reducer union and the thin pipe can be effectively welded.

Description

Technical Field

[0001] The invention relates to the technical field of pipeline welding, and in particular to a construction process for variable diameter annular automatic internal welding. Background Art

[0002] At present, large-diameter pipelines at home and abroad have achieved full-automatic welding and large-scale flow construction in plain areas. The China-Russia East Line adopts full-automatic welding and combined automatic welding. Fully automatic welding refers to the automatic welding process of the combination of internal welding machine + external welding machine. The combined automatic welding process refers to the manual or semi-automatic method to complete the root welding, and the external welding machine to complete the filling and cover welding. However, the full-automatic welding technology for interconnection, in and out of the station and steep slope sections is still in the early exploration stage. Especially in the construction of steep slope pipelines, the pipeline is in an inclined state, which increases the difficulty of full-automatic welding construction.

[0003] When using an internal welding machine to weld the inner seam of a reducer pipe joint, since the thick pipe and the thin pipe are connected by a tapered pipe, the diameters of the two inner seams of the reducer pipe joint are different. Therefore, it is not convenient for a conventional internal welding machine to weld the inner seam of the reducer joint. When the existing internal welding machine welds the inner seam of the reducer joint, it is not convenient to stabilize the internal welding machine, and the internal welding machine is prone to displacement during the welding process, resulting in the weld after welding failing to meet the design requirements.

[0004] When the internal welder enters the pipeline joint position and moves in the pipeline to weld the joint, the pipeline will vibrate. After the pipeline vibrates, the axial direction between the pipelines is prone to offset, and the width of the joint that has been positioned and set is prone to change, which may cause the weld to fail to meet the design requirements in the subsequent welding process of the internal welder. Summary of the invention

[0005] The technical problem to be solved by the present invention is to ensure the stability of the internal welding work, thereby ensuring the welding quality of the internal weld of the reducer joint. The reducer ring automatic internal welding construction process of the present invention is suitable for automatic welding at the pipe diameter change point, which can improve the welding quality and the welding quality is stable with little fluctuation.

[0006] In order to achieve the above object, the technical solution provided by the present invention is:

[0007] The variable diameter annular automatic internal welding construction process is characterized by comprising the following steps:

[0008] S1. The thick tube and the thin tube to be welded are butt-jointed and positioned through a tapered tube, a second inner seam and a second outer seam are formed between the small ends of the thin tube and the tapered tube, and a first inner seam and a first outer seam are formed between the large ends of the thick tube and the tapered tube;

[0009] S2, putting the variable diameter annular automatic internal welding machine into the thick pipe, and making the driving wheel sets of the driving mechanism on both sides of the body of the variable diameter annular automatic internal welding machine contact with the inner wall of the thick pipe, starting the driving wheel sets of the driving mechanism, so that the variable diameter annular automatic internal welding machine as a whole moves in the direction of the thin pipe inside the thick pipe;

[0010] S3, retracting the driving mechanism on the left side of the variable diameter ring automatic internal welding machine, and after the driving mechanism on the left side of the variable diameter ring automatic internal welding machine enters into the capillary tube, expanding the driving mechanism on the left side, and making the driving wheel set of the driving mechanism on the left side of the variable diameter ring automatic internal welding machine contact with the inner wall of the capillary tube;

[0011] S4, making the limiting mechanism on the body of the variable diameter annular automatic internal welding machine tightly against the inner conical surface of the conical tube, and adjusting the welding mechanisms on the left and right sides of the body of the variable diameter annular automatic internal welding machine so that the two welding mechanisms correspond to the second inner seam and the first inner seam respectively;

[0012] S5. Adjust the direction of the driving wheel set so that the driving wheel sets of the driving mechanisms on both sides of the variable diameter annular automatic internal welding machine are deflected in the same direction by the same angle, and the deflection angle of the driving wheel set is less than 90 degrees. Then, start the driving wheel set so that the driving wheel set rotates relative to the limiting mechanism, thereby driving the driving mechanisms and welding mechanisms on both sides to rotate circumferentially in the thin tube and the thick tube respectively. During the rotation of the driving mechanism, the first inner seam and the second inner seam are welded by the welding mechanism.

[0013] S6. Welding the first outer seam and the second outer seam by using an outer welding machine.

[0014] Specifically, the variable diameter annular automatic internal welding machine comprises a machine body, a limiting mechanism is installed on the machine body, both sides of the machine body are rotatably connected with a driving mechanism, and a welding mechanism and a driving wheel set are installed on the driving mechanism.

[0015] Specifically, the limiting mechanism includes limiting parts evenly distributed on the circumference and fixed on the body, the limiting parts include a first electric push rod fixedly connected to the body, the telescopic rod of the first electric push rod is rotatably connected to a connecting plate through a pin shaft, and a plurality of protruding columns are fixedly connected to one end of the connecting plate facing away from the body.

[0016] Specifically, the axial direction of the first electric push rod is perpendicular to the axial direction of the body, the length direction of the connecting plate is parallel to the axial direction of the body, a torsion spring is sleeved on the pin shaft, one end of the torsion spring is fixed by the telescopic rod of the first electric telescopic cylinder, and the other end of the torsion spring is fixed by the connecting plate.

[0017] Specifically, the driving mechanism includes a rotating body that is concentric with the machine body, the rotating body is rotatably connected to the machine body, an electric telescopic cylinder is fixed to one end of the rotating body away from the machine body, the electric telescopic cylinder is concentric with the rotating body, a fixed plate is fixed on the telescopic rod of the electric telescopic cylinder, a first connecting rod is rotatably connected to the fixed plate, a second connecting rod is rotatably connected to the rotating body, the first connecting rod and the second connecting rod are rotatably connected to form a scissors-type mechanism, a connecting block is rotatably connected to the upper end of the first connecting rod, a guide groove is provided on the connecting block, the second connecting rod is slidably connected to the guide groove, the driving wheel group includes a plurality of blind holes provided on the side of the connecting block facing away from the electric telescopic cylinder, motors are fixed in the blind holes, a wheel seat is fixed on the output shaft of the motor, and an electric roller is rotatably connected in the wheel seat.

[0018] Specifically, the length direction of the connecting block is parallel to the axial direction of the rotating body, the length direction of the guide groove is parallel to the length direction of the connecting block, a plurality of blind holes are evenly arranged in the length direction of the connecting block, the axis of the motor is perpendicular to the axis of the rotating body, and the axis of the electric roller is perpendicular to the axis of the motor.

[0019] Specifically, the welding mechanism includes a rail groove provided on the rotating body, the length direction of the rail groove is parallel to the axial direction of the rotating body, an electric control slide rail is installed in the rail groove, a second electric push rod is fixed on the slider of the electric control slide rail, the axial direction of the second electric push rod is perpendicular to the axial direction of the rotating body, and a welding gun is fixed on the telescopic rod of the second electric push rod.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. The welding gun of the present invention is height-adjustable. When welding the reducer and the inner seam between the thick tube and the thin tube, the distance between the welding gun and the inner seam can be ensured, thereby effectively welding the reducer and the inner seams of different diameters between the thick tube and the thin tube.

[0022] 2. When welding the inner seam, the driving wheel group is deflected at the same angle in the direction of the thin tube away from the end of the tapered tube, and then when the driving wheel group is started, the variable diameter ring automatic internal welding machine has a tendency to spiral in the direction of the thin tube away from the end of the tapered tube during the rotation in the pipeline, so that the limit mechanism can always apply pressure to the inner cone surface of the tapered tube. The thin tube, tapered tube and thick tube can also effectively prevent displacement during the rotation welding of the variable diameter ring automatic internal welding machine in an inclined state, ensuring the welding quality of the inner weld.

[0023] 3. When welding the reducer and the inner seam between the thick tube and the thin tube, the driving wheel groups on both sides can be in close contact with the inner wall of the thick tube and the inner wall of the thin tube respectively, thereby effectively ensuring the stable performance during the internal welding rotation process. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1It is a schematic diagram of a variable diameter annular automatic internal welding machine.

[0025] Figure 2 A cross-sectional view of the connection block.

[0026] Figure 3 This is a cross-sectional view of the combination of thick tube, thin tube and tapered tube.

[0027] Figure 4 It is a schematic diagram of embodiment 1.

[0028] Figure 5 This is a schematic diagram of the second embodiment.

[0029] The names of the parts in the attached drawings are:

[0030] 1. Machine body; 2. First electric push rod; 3. Connecting plate; 4. Boss; 5. Rotating body; 6. First connecting rod; 7. Track groove; 8. Second electric push rod; 9. Welding gun; 10. Electric telescopic cylinder; 11. Fixing plate; 12. Second connecting rod; 13. Guide groove; 14. Connecting block; 15. Electric roller; 16. Motor; 17. Blind hole; 18. Wheel seat; 19. Thick tube; 20. Conical tube; 21. Thin tube; 22. First inner seam; 23. Second inner seam; 231. Second outer seam; 221. First outer seam. DETAILED DESCRIPTION

[0031] Embodiment 1:

[0032] like Figure 1-Figure 2 As shown, the variable diameter annular automatic internal welding machine comprises a machine body 1, on which a limiting mechanism is installed, both sides of the machine body 1 are rotatably connected with a driving mechanism, on which a welding mechanism and a driving wheel set are installed.

[0033] The limiting mechanism includes limiting members evenly distributed on the circumference and fixed on the machine body 1, and the limiting members include a first electric push rod 2 fixedly connected to the machine body 1, and the axial direction of the first electric push rod 2 is perpendicular to the axial direction of the machine body 1. A connecting plate 3 is rotatably connected to the telescopic rod of the first electric push rod 2 through a pin shaft, and the length direction of the connecting plate 3 is parallel to the axial direction of the machine body 1. A plurality of protruding columns 4 are fixedly connected to one end of the connecting plate 3 facing away from the machine body 1. A torsion spring is sleeved on the pin shaft, one end of the torsion spring is fixed by the telescopic rod of the first electric telescopic cylinder 10, and the other end of the torsion spring is fixed by the connecting plate 3.

[0034] A protrusion is provided on the surface of the connecting plate 3 facing the body 1. When the telescopic rod of the first electric push rod 2 is shortened to the shortest length, the protrusion is pressed against the surface of the body 1, limiting the connecting plate 3 to prevent the connecting plate 3 from swinging. When the telescopic rod of the first electric push rod 2 is extended, the protrusion is separated from the surface of the body 1, and the connecting plate 3 rotates relative to the telescopic rod of the first electric push rod 2, so as to facilitate the adjustment of the inclination angle of the connecting plate 3 and fit it with the inner wall of the cone tube 20. The above-mentioned technical means are all existing common sense technologies, and the protrusion is not shown in the drawings of the specification.

[0035] The driving mechanism includes a rotating body 5 which is concentric with the machine body 1, and the rotating body 5 is rotatably connected to the machine body 1. An electric telescopic cylinder 10 is fixed to the end of the rotating body 5 away from the machine body 1, and the electric telescopic cylinder 10 is concentric with the rotating body 5. A fixed plate 11 is fixed to the telescopic rod of the electric telescopic cylinder 10. A first connecting rod 6 is rotatably connected to the fixed plate 11, and a second connecting rod 12 is rotatably connected to the rotating body 5. The first connecting rod 6 and the second connecting rod 12 are rotatably connected to form a scissor mechanism. A connecting block 14 is rotatably connected to the upper end of the first connecting rod 6, and the length direction of the connecting block 14 is parallel to the axial direction of the rotating body 5. A guide groove 13 is provided on the connecting block 14, and the length direction of the guide groove 13 is parallel to the length direction of the connecting block 14. The second connecting rod 12 is slidably connected to the guide groove 13.

[0036] The driving wheel assembly includes a plurality of blind holes 17 opened on the side of the connecting block 14 facing away from the electric telescopic cylinder 10, and the plurality of blind holes 17 are evenly arranged in the length direction of the connecting block 14. A motor 16 is fixed in each of the blind holes 17, and the axis of the motor 16 is perpendicular to the axis of the rotating body 5. A wheel seat 18 is fixed on the output shaft of the motor 16, and an electric roller 15 is rotatably connected in the wheel seat 18, and the axis of the electric roller 15 is perpendicular to the axis of the motor 16.

[0037] The welding mechanism includes a rail groove 7 arranged on the rotating body 5, the length direction of the rail groove 7 is parallel to the axial direction of the rotating body 5, an electric control slide rail is installed in the rail groove 7, a second electric push rod 8 is fixed on the slider of the electric control slide rail, the axial direction of the second electric push rod 8 is perpendicular to the axial direction of the rotating body 5, and a welding gun 9 is fixed on the telescopic rod of the second electric push rod 8.

[0038] The welding mechanism can be set to be multiple, generally set in pairs, such as 2, 4, 6, etc. The number of the welding mechanism is set according to the size of the pipe diameter; the larger the pipe diameter, the more welding mechanisms there are; the smaller the pipe diameter, the fewer welding mechanisms there are. When the welding mechanism is welding, it only needs to rotate within a certain angle range to complete the welding work of the entire annular weld, thereby improving work efficiency.

[0039] The construction process of variable diameter annular automatic internal welding includes the following steps:

[0040] S1. The thick tube 19 and the thin tube 21 to be welded are butt-jointed and positioned through the tapered tube 20, so that a second inner seam 23 and a second outer seam 231 are formed between the small ends of the thin tube 21 and the tapered tube 20, and a first inner seam 22 and a first outer seam 221 are formed between the large ends of the thick tube 19 and the tapered tube 20.

[0041] S2, put the variable diameter annular automatic internal welding machine into the thick tube 19, start the electric telescopic cylinders 10 on both sides of the machine body 1, and retract the telescopic rods of the electric telescopic cylinders 10. During the retraction of the telescopic rods of the electric telescopic cylinders 10, the fixed plate 11 approaches the rotating body 5 on one side thereof. During the process of the fixed plate 11 approaching the rotating body 5 on one side thereof, the angle between the first connecting rod 6 and the second connecting rod 12 decreases. At the same time, the end of the second connecting rod 12 away from the rotating body 5 slides in the guide groove 13. During the process of the angle between the first connecting rod 6 and the second connecting rod 12 decreasing, the connecting block 14 gradually approaches the inner wall of the thick tube 19. At this time, the axis of the electric roller 15 is perpendicular to the axis of the thick tube 19. After the electric roller 15 contacts the inner wall of the thick tube 19, the electric roller 15 is started, so that the variable diameter annular automatic internal welding machine as a whole moves to the left in the thick tube 19 and approaches the thin tube 21.

[0042] S3. When the left driving mechanism is about to enter the conical tube 20, the telescopic rod of the left electric telescopic cylinder 10 is extended. During the extension of the telescopic rod of the left electric telescopic cylinder 10, the left fixed plate 11 moves away from the left rotating body 5. During the movement of the left fixed plate 11 away from the left rotating body 5, the angle between the first connecting rod 6 and the second connecting rod 12 increases. At the same time, the end of the second connecting rod 12 away from the rotating body 5 slides in the guide groove 13. During the increase of the angle between the first connecting rod 6 and the second connecting rod 12, the connecting block 14 gradually moves away from the inner wall of the thick tube 19, thereby achieving contraction. After the left driving mechanism contracts, the electric roller 15 of the right driving mechanism is started, so that the variable diameter annular automatic internal welding machine continues to move to the left.

[0043] When the left driving mechanism enters the capillary tube 21, the telescopic rod of the left electric telescopic cylinder 10 is retracted, and the electric roller 15 of the left driving mechanism is in close contact with the inner wall of the capillary tube 21. At this time, the machine body 1 is located in the conical tube 20.

[0044] S4, then start the first electric push rod 2, so that the telescopic rod of the first electric push rod 2 drives the connecting plate 3 to approach the inner conical surface of the conical tube 20, and makes the protruding column 4 on the connecting plate 3 tightly contact with the inner conical surface of the conical tube 20.

[0045] Then, the electric control slide rail is started to change the position of the welding gun 9 in the axial direction of the rotating body 5, so that the welding guns 9 on the left and right sides correspond to the second inner seam 23 and the first inner seam 22 respectively. Then, the second electric push rods 8 on the left and right sides are started to keep a suitable welding distance between the welding guns 9 on the left and right sides and the second inner seam 23 and the first inner seam 22 respectively.

[0046] S5, then start the motor 16 at the same time, so that the motor 16 drives the electric roller 15 to deflect to the rear side at the same angle at the same time, and the deflection angle of the electric roller 15 is controlled to be less than 90 degrees. Then start the electric roller 15 to rotate in the same direction at the same time, so that the variable diameter annular automatic internal welding machine has a tendency to move from the thick tube 19 to the thin tube 21. While the electric roller 15 rotates relative to the limiting mechanism, the driving mechanism and welding mechanism on both sides rotate circumferentially in the thick tube 19 and the thin tube 21 in the direction of the deflection of the electric roller 15. Because the boss 4 is in close contact with the inner conical surface of the tapered tube 20, there is a large friction between the boss 4 and the tapered tube 20, and the limiting mechanism is stationary relative to the tapered tube 20.

[0047] S6. Welding the first outer seam 221 and the second outer seam 231 by using an outer welding machine.

[0048] like Figure 4 As shown, the motor 16 drives the electric roller 15 to deflect to the rear side at the same angle at the same time, and the angle of deflection of the electric roller 15 is less than 90 degrees. Taking the electric roller 15 in the capillary 21 as an example, the electric roller 15 in the capillary 21 has two motion states during rotation, one is that the electric roller 15 as a whole makes circumferential motion in the capillary 21, and the other is that the electric roller 15 makes rotational motion around its axis. Since the electric roller 15 deflects to the rear side at the same angle at the same time, if the variable diameter annular automatic internal welding machine is not blocked, the variable diameter annular automatic internal welding machine will spirally rotate to the left direction in the capillary 21. However, in this embodiment, the connecting plate 3 is tightly pressed against the inner cone surface of the conical tube 20 through the protruding column 4, and the variable diameter annular automatic internal welding machine is blocked. Therefore, the driving mechanism and welding mechanism on both sides can only make circumferential motion in the capillary 21 and the thick tube 19.

[0049] During the rotation of the electric roller 15, the contact point between the electric roller 15 and the inner wall of the capillary 21 will generate two velocity components, which are the rotation speed R of the electric roller 15 and the speed T of the electric roller 15 making circumferential motion in the capillary 21. Since the angle of the electric roller 15 deflected to the rear side is less than 90 degrees, the variable diameter annular automatic internal welding machine is limited in the axial direction of the capillary 21. Therefore, an angle is generated between the rotation speed R of the electric roller 15 and the speed T of the electric roller 15 making circumferential motion in the capillary 21, that is, the speed of the contact point between the electric roller 15 and the inner wall of the capillary 21 will not be relatively zero. During the circumferential motion of the driving mechanism and the welding mechanism in the pipeline, sliding friction will occur between the electric roller 15 and the inner wall of the pipeline. Under the action of the sliding friction between the electric roller 15 and the inner wall of the pipe, the convex column 4 can maintain the pressure on the inner conical surface of the tapered pipe 20, and then the variable diameter annular automatic internal welding machine will not be displaced in the axial direction of the thin pipe during the circumferential movement of the driving mechanism and the welding mechanism in the pipe, thereby ensuring that the welding guns 9 on the left and right sides always correspond to the second inner seam 23 and the first inner seam 22. The thin pipe 21, the tapered pipe 20 and the thick pipe 19 can also effectively prevent displacement in the axial direction of the pipe during welding by the variable diameter annular automatic internal welding machine in the inclined state, thereby ensuring the welding quality of the weld.

[0050] When the driving mechanisms and welding mechanisms on both sides rotate in the thick tube 19 and the thin tube 21 respectively, the welding guns 9 on the left and right sides are used to weld the second inner seam 23 and the first inner seam 22 respectively.

[0051] Embodiment 2:

[0052] In step S5, the motor 16 is started at the same time, so that the motor 16 drives the electric roller 15 to deflect to the rear side at the same angle at the same time, and the deflection angle of the electric roller 15 is controlled to be less than 90 degrees. Then the electric roller 15 is started at the same time, and the electric roller 15 rotates relative to the limiting mechanism while the driving mechanism and the welding mechanism on both sides rotate in the thick tube 19 and the thin tube 21 respectively. Among them, the rotation direction of the electric electric roller 15 in the thin tube 21 makes the variable diameter annular automatic internal welding machine have a tendency to move from the thick tube 19 to the thin tube 21, and the rotation direction of the electric electric roller 15 in the thick tube 19 makes the variable diameter annular automatic internal welding machine have a tendency to move from the thin tube 21 to the thick tube 19. The rotation direction of the electric roller 15 in the thin tube 21 is opposite to the rotation direction of the electric roller 15 in the thick tube 19. The rotation speed of the electric roller 15 in the thick tube 19 is lower than the rotation speed of the electric roller 15 in the thin tube 21, so that the variable diameter annular automatic internal welding machine has a tendency to move from the thick tube 19 to the thin tube 21. Figure 5As shown, the driving mechanism and welding mechanism in the thin tube 21 rotate in the direction of the deflection of the electric roller 15, and the rotation direction of the driving mechanism and welding mechanism in the thin tube 21 is the direction indicated by the arrow N. The driving mechanism and welding mechanism in the thick tube 19 rotate in the direction opposite to the deflection of the electric roller 15, and the rotation direction of the driving mechanism and welding mechanism in the thick tube 19 is the direction indicated by the arrow S.

[0053] When the driving mechanism and welding mechanism in the capillary tube 21 make circumferential motion in the capillary tube 21, sliding friction will occur between the electric roller 15 in the capillary tube 21 and the inner wall of the capillary tube 21. Under the action of the sliding friction between the electric roller 15 in the capillary tube 21 and the inner wall of the capillary tube 21, the protrusion 4 can maintain the pressure on the inner conical surface of the conical tube 20, and the variable diameter annular automatic internal welding machine will not be displaced in the axial direction of the capillary tube 21. At the same time, under the action of the sliding friction between the electric roller 15 in the capillary tube 21 and the inner wall of the capillary tube 21, the capillary tube 21 can be tightly pressed against the conical tube 20.

[0054] When the driving mechanism and the welding mechanism in the thick tube 19 make circumferential motion in the thick tube 19, sliding friction occurs between the electric roller 15 in the thick tube 19 and the inner wall of the thick tube 19. Under the action of the sliding friction between the electric roller 15 in the thick tube 19 and the inner wall of the thick tube 19, the thick tube 19 can be pressed against the conical tube 20.

[0055] In this embodiment, by controlling the direction and rotation speed of the driving mechanism and the welding mechanism in the thick tube 19 and the thin tube 21, the thick tube 19, the thin tube 21 and the limiting mechanism of the variable diameter annular automatic internal welding machine can be pressed against the tapered tube 20, thereby ensuring the welding quality of the welds between the thick tube 19, the tapered tube 20 and the thin tube 21.

[0056] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. The variable diameter annular automatic internal welding construction process is characterized by: The following steps are involved: S1, the thick tube (19) and the thin tube (21) to be welded are butt-jointed and positioned through the conical tube (20), a second inner seam (23) and a second outer seam (231) are formed between the small ends of the thin tube (21) and the conical tube (20), and a first inner seam (22) and a first outer seam (221) are formed between the large ends of the thick tube (19) and the conical tube (20); S2, placing the variable diameter annular automatic internal welding machine into the thick tube (19), and making the driving wheel sets of the driving mechanisms on both sides of the variable diameter annular automatic internal welding machine body (1) contact the inner wall of the thick tube (19), and starting the driving wheel sets of the driving mechanisms, so that the variable diameter annular automatic internal welding machine as a whole moves in the direction of the thin tube (21) inside the thick tube (19); S3, retracting the drive mechanism on the left side of the variable diameter annular automatic internal welding machine, and after the drive mechanism on the left side of the variable diameter annular automatic internal welding machine enters into the capillary tube (21), expanding the drive mechanism on the left side, and making the drive wheel set of the drive mechanism on the left side of the variable diameter annular automatic internal welding machine contact the inner wall of the capillary tube (21); S4, making the limiting mechanism on the body (1) of the variable diameter annular automatic internal welding machine tightly against the inner conical surface of the conical tube (20), and adjusting the welding mechanisms on the left and right sides of the body (1) of the variable diameter annular automatic internal welding machine so that the two welding mechanisms correspond to the second inner seam (23) and the first inner seam (22) respectively; S5, adjusting the direction of the driving wheel group so that the driving wheel groups of the driving mechanisms on both sides of the variable diameter annular automatic internal welding machine are deflected in the same direction by the same angle, and the deflection angle of the driving wheel group is less than 90 degrees, and then starting the driving wheel group so that the driving wheel group rotates relative to the limiting mechanism, thereby driving the driving mechanisms and welding mechanisms on both sides to rotate circumferentially in the thin tube (21) and the thick tube (19), respectively, and using the welding mechanism to weld the first inner seam (22) and the second inner seam (23) during the rotation of the driving mechanism; S6. Using an external welding machine to weld the first outer seam (221) and the second outer seam (231).

2. According to the variable diameter annular automatic internal welding construction process of claim 1, it is characterized in that: The variable diameter annular automatic internal welding machine comprises a machine body (1), a limiting mechanism is installed on the machine body (1), both sides of the machine body (1) are rotatably connected with a driving mechanism, and a welding mechanism and a driving wheel set are installed on the driving mechanism.

3. According to claim 2, the variable diameter annular automatic internal welding construction process is characterized in that: The limiting mechanism comprises limiting members evenly distributed around the circumference and fixed on the machine body (1), the limiting members comprising a first electric push rod (2) fixedly connected to the machine body (1), a connecting plate (3) rotatably connected to the telescopic rod of the first electric push rod (2) via a pin, and a plurality of protruding columns (4) fixedly connected to one end of the connecting plate (3) facing away from the machine body (1).

4. According to claim 3, the variable diameter annular automatic internal welding construction process is characterized in that: The axial direction of the first electric push rod (2) is perpendicular to the axial direction of the machine body (1), the length direction of the connecting plate (3) is parallel to the axial direction of the machine body (1), a torsion spring is sleeved on the pin shaft, one end of the torsion spring is fixed by the telescopic rod of the first electric telescopic cylinder (10), and the other end of the torsion spring is fixed by the connecting plate (3).

5. According to claim 2, the variable diameter annular automatic internal welding construction process is characterized in that: The driving mechanism comprises a rotating body (5) which is concentric with the machine body (1), the rotating body (5) being rotatably connected to the machine body (1), an electric telescopic cylinder (10) being fixed to one end of the rotating body (5) away from the machine body (1), the electric telescopic cylinder (10) being concentric with the rotating body (5), a fixing plate (11) being fixed to the telescopic rod of the electric telescopic cylinder (10), a first connecting rod (6) being rotatably connected to the fixing plate (11), a second connecting rod (12) being rotatably connected to the rotating body (5), the first connecting rod (6) and the second connecting rod (12) being connected to the rotating body (5), The scissor mechanism is formed by rotational connection. The upper end of the first connecting rod (6) is rotationally connected to a connecting block (14). A guide groove (13) is provided on the connecting block (14). The second connecting rod (12) is slidably connected to the guide groove (13). The driving wheel group includes a plurality of blind holes (17) provided on the side of the connecting block (14) facing away from the electric telescopic cylinder (10). Motors (16) are fixed in the blind holes (17). A wheel seat (18) is fixed on the output shaft of the motor (16). An electric roller (15) is rotationally connected in the wheel seat (18).

6. The variable diameter annular automatic internal welding construction process according to claim 5 is characterized in that: The length direction of the connecting block (14) is parallel to the axial direction of the rotating body (5), the length direction of the guide groove (13) is parallel to the length direction of the connecting block (14), a plurality of blind holes (17) are evenly arranged in the length direction of the connecting block (14), the axis of the motor (16) is perpendicular to the axis of the rotating body (5), and the axis of the electric roller (15) is perpendicular to the axis of the motor (16).

7. The variable diameter annular automatic internal welding construction process according to claim 5 is characterized in that: The welding mechanism comprises a rail groove (7) arranged on a rotating body (5), the length direction of the rail groove (7) is parallel to the axial direction of the rotating body (5), an electric control slide rail is installed in the rail groove (7), a second electric push rod (8) is fixed on the slider of the electric control slide rail, the axial direction of the second electric push rod (8) is perpendicular to the axial direction of the rotating body (5), and a welding gun (9) is fixed on the telescopic rod of the second electric push rod (8).

Images