A manufacturing process for internally threaded pipes

Abstract

This invention belongs to the field of internal threaded pipe manufacturing technology, specifically a process for manufacturing internal threaded pipes, comprising the following sequential steps: S1, raw material stacking; S2, double-ended feeding; S3, steel strip cleaning; S4, internal thread cutting; S5, forming and welding; S6, internal leveling; S7, weld polishing and initial sizing; S8, online bright annealing; S9, precision sizing; S10, servo sawing; S11, automatic sorting; S12, coiling; S13, inspection and packaging. This internal threaded pipe manufacturing process, by setting thirteen continuously connected process steps from beginning to end, and integrating double-ended feeding, online cleaning, internal thread cutting, laser welding, online bright annealing, and servo sawing, achieves fully automated continuous production of internal threaded pipes, significantly improving production efficiency and product consistency.

Description

Technical Field

[0001] This invention relates to the field of internal threaded pipe manufacturing technology, and in particular to a process for preparing internal threaded pipes. Background Technology

[0002] Internally threaded tubes are high-efficiency heat transfer elements with helical teeth on their inner walls, and are widely used in equipment such as air conditioners, refrigeration units, and heat exchangers.

[0003] Traditional internal threaded pipe manufacturing processes often employ segmented operations with loose connections between processes, low automation, and significant challenges in weld quality control during the forming and welding process. Defects such as weld misalignment, excessive weld reinforcement, and uneven inner walls are prone to occur, leading to high false alarm rates and reduced heat exchange efficiency in subsequent eddy current testing. Furthermore, existing laser welding stages lack sufficient real-time tracking and adaptive adjustment capabilities for weld position, making it difficult to guarantee welding stability during high-speed continuous production. Therefore, this application proposes a new internal threaded pipe manufacturing process. Summary of the Invention

[0004] Based on the aforementioned technical problems, this invention proposes a process for manufacturing internally threaded pipes.

[0005] The present invention proposes a process for manufacturing internally threaded pipes, comprising the following steps performed sequentially:

[0006] S1. Raw material stacking: Stack the steel strip raw materials in the raw material stacking area for later use.

[0007] S2, Dual-head feeding: The steel strip is fed continuously by alternating feeding from two dual-head feeding discs.

[0008] S3. Steel strip cleaning: After feeding, the steel strip is sent into the steel strip cleaning water tank for surface cleaning to remove oil and impurities.

[0009] S4. Internal thread cutting: Using a thread cutting device, the required thread line is cut out on the surface of the steel strip.

[0010] S5. Forming and Welding: The cleaned steel strip is gradually rolled into a round tube shape by the forming unit and then welded to the joint to form a straight seam welded pipe.

[0011] S6. Internal leveling: The internal leveling device is used to level the inner wall of the welded pipe to eliminate the protrusions on the inner wall of the weld.

[0012] S7. Weld polishing and initial sizing: The weld seam of the pipe is polished using a weld polishing and initial sizing device to make the weld seam flush with the outer wall of the pipe. At the same time, the pipe is initially sized to obtain the preliminary outer diameter.

[0013] S8. Online bright annealing: The pre-sized pipes are sent to an online bright annealing device for bright annealing under a protective atmosphere to eliminate internal stress.

[0014] S9. Precision sizing: The annealed pipe is precisely sized using a precision sizing device to ensure that the outer diameter of the pipe meets the tolerance range required for the finished product.

[0015] S10, Servo sawing: The pipe cutting machine with dual servo saw blades cuts the pipe to a fixed length according to the set length.

[0016] S11. Automatic sorting: The cut pipes are sorted by quality status and specifications by an automatic sorting rack.

[0017] S12. Coiling: The sorted qualified pipes are coiled into a coil shape using a coiling machine.

[0018] S13. Inspection and Packaging: The coiled pipe is sent to the coil inspection and packaging area for final inspection, weighing, bundling and packaging to obtain the finished internally threaded pipe.

[0019] Preferably, the forming unit in S4 includes a feeding guide section, a roller preforming section, a closed forming section, a weld alignment section, a laser welding section, and a discharge cooling section arranged sequentially along the pipe traveling direction.

[0020] The above technical solution enables continuous and stable forming of steel strip into straight seam welded pipe, with each segment working in concert, reducing billet distortion and weld offset.

[0021] Preferably, the laser welding section includes a support, and the inner top surface of the support is provided with a laser welding machine, an adjustment mechanism for adjusting the laser welding machine, and a weld seam visual tracking sensor assembly.

[0022] The above technical solution enables real-time acquisition of weld position information and automatic adjustment of welding head posture, achieving high-precision weld tracking.

[0023] Preferably, the weld seam visual tracking sensor assembly includes a laser structured light generator and a high-speed industrial camera. The laser structured light generator projects laser stripes onto the weld seam area of ​​the tube blank, and the high-speed industrial camera acquires images of the weld seam area. The high-speed industrial camera has a built-in image processing module, which extracts the weld seam center position and weld seam gap width. The output of the image processing module is connected to the adjustment mechanism.

[0024] The above technical solution directly links visual perception with the actuator, shortening the control response time.

[0025] Preferably, the image processing module uses a Kalman filter algorithm to predict the weld offset and gap width at the next moment, generates a feedforward compensation signal, and establishes a Kalman filter state-space model: , ,in, for The state vector at time t, Here is the state transition matrix. for The state vector at time t, For the input control matrix, for The control input vector at time t, For process noise, for The observation vector at time t, For the observation matrix, To observe noise.

[0026] The above technical solutions effectively compensate for system response lag and improve the dynamic performance of weld seam tracking.

[0027] Preferably, the image processing module receives the weld offset and gap width predicted by the Kalman filter at the next moment via a multivariable adaptive fuzzy PID controller, and calculates the correction amount of the PID parameters online using a fuzzy rule base to obtain real-time PID parameters. Finally, it generates the final control output by combining the feedforward compensation signal, as shown in the formula: , , , ,in, This refers to the lateral offset deviation of the weld. Set a value for the lateral offset of the weld. This is the measured value of the lateral offset of the weld. This refers to the deviation in weld gap width. Set a value for the weld gap width. This is the measured value of the weld gap width. This represents the rate of change of the lateral offset deviation of the weld. This represents the lateral offset deviation of the weld at the previous moment. The sampling period is This represents the rate of change of weld gap width deviation. This represents the deviation in weld gap width at the previous moment.

[0028] The above technical solutions enable independent control of weld position and gap width, adapting to different pipe specifications and speed variations, thereby improving accuracy and stability.

[0029] Preferably, the adjustment mechanism includes two mounting slots formed on the inner top surface of the bracket, the laser structured light generator and the high-speed industrial camera are both mounted on the inner top surface of the bracket, micro hydraulic cylinders are installed on the inner walls of the two mounting slots, and a connecting plate is fixedly connected to one end of the piston rod of the two micro hydraulic cylinders. The laser welding machine is disposed on the side surface of the connecting plate away from the mounting slots.

[0030] The above technical solution utilizes a miniature hydraulic cylinder to achieve precise horizontal translation of the laser welding machine, resulting in a compact structure and stable adjustment.

[0031] Preferably, the inner walls of both mounting slots are fixedly connected with limit rods, the inner wall of the connecting plate is slidably connected to the surface of the limit rods, and the surface of the connecting plate is slidably engaged with the inner wall of the mounting slot.

[0032] The above technical solution ensures the guiding accuracy and torsional resistance of the connecting plate during movement.

[0033] Preferably, a lifting hydraulic cylinder is provided between the connecting plate and the laser welding machine, and one end of the piston rod of the lifting hydraulic cylinder is fixedly connected to the laser welding machine.

[0034] The above technical solution enables the laser welding machine to be independently adjustable in the vertical direction, making it easy to adapt to different pipe diameters.

[0035] Preferably, electromagnets are provided on the opposite side surfaces of the two connecting plates and the lifting hydraulic cylinder, and the two electromagnets attract each other when energized.

[0036] The above technical solution allows the lifting hydraulic cylinder to be attached to one of the two connecting plates and separated from the other when the laser welding machine needs to be moved quickly, thereby improving maintenance convenience and safety.

[0037] The beneficial effects of this invention are as follows:

[0038] 1. By setting up thirteen continuous process steps from beginning to end, and integrating double-head feeding, online cleaning, internal thread cutting, laser welding, online bright annealing, and servo sawing, fully automated continuous production of internal threaded tubes is achieved, which greatly improves production efficiency and product consistency.

[0039] 2. By setting up a weld seam visual tracking sensor assembly, and combining it with a Kalman filter feedforward prediction algorithm and a multivariable adaptive fuzzy PID controller, the weld seam offset and gap width can be predicted and compensated in advance, which significantly reduces the welding defect rate and ensures the stability of welding quality.

[0040] 3. By setting up an adjustment mechanism, the laser welding machine can be adjusted with high precision and quick separation in both horizontal and vertical directions, which not only meets the centering requirements in production, but also facilitates equipment maintenance. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of a manufacturing process for an internally threaded pipe proposed in this invention;

[0042] Figure 2 This is a flowchart illustrating a process for manufacturing an internally threaded pipe according to the present invention.

[0043] Figure 3 This is a system block diagram of a process for manufacturing internally threaded pipes proposed in this invention;

[0044] Figure 4 This is a three-dimensional view of the forming unit structure for a process of manufacturing internally threaded pipes proposed in this invention;

[0045] Figure 5 This is a three-dimensional view of the support structure for a process of manufacturing an internally threaded tube proposed in this invention;

[0046] Figure 6 This is a three-dimensional structural view of a laser welding machine for a process of preparing internally threaded pipes proposed in this invention.

[0047] Figure 7 This is a three-dimensional view of the lifting hydraulic cylinder structure for a process of manufacturing an internally threaded pipe proposed in this invention;

[0048] Figure 8 This is a perspective view of the connecting plate structure for a process of manufacturing an internally threaded pipe proposed in this invention;

[0049] Figure 9 This is a plan view of the double-headed feeding tray structure of a process for manufacturing internally threaded tubes proposed in this invention;

[0050] Figure 10 This is a plan view of the internal leveling device structure for an internal threaded pipe manufacturing process proposed in this invention;

[0051] Figure 11 This is a plan view of the weld polishing and initial sizing device for an internally threaded pipe manufacturing process proposed in this invention.

[0052] Figure 12 This is a plan view of the online bright annealing device for the preparation process of internally threaded tubes proposed in this invention;

[0053] Figure 13 This is a plan view of the sizing device for a threaded tube manufacturing process proposed in this invention.

[0054] Figure 14This is a plan view of a dual-servo saw blade pipe cutting machine for a process of preparing internally threaded pipes proposed in this invention;

[0055] Figure 15 This is a plan view of an automatic sorting rack structure for an internally threaded tube manufacturing process proposed in this invention;

[0056] Figure 16 This is a plan view of the coil winding machine structure for a coiled tube manufacturing process proposed in this invention.

[0057] In the diagram: 1. Double-headed feeding tray; 2. Steel strip cleaning water tank; 3. Thread cutting device; 4. Forming unit; 5. Internal leveling device; 6. Weld polishing and initial sizing device; 7. Online bright annealing device; 8. Fine sizing device; 9. Dual servo saw blade pipe cutting machine; 10. Automatic sorting rack; 11. Coil winding machine; 12. Support; 13. Laser welding machine; 14. Mounting groove; 141. Miniature hydraulic cylinder; 142. Connecting plate; 143. Limiting rod; 144. Lifting hydraulic cylinder; 145. Electromagnet; 15. Laser structured light generator; 16. High-speed industrial camera. Detailed Implementation

[0058] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0059] Reference Figures 1-16 A process for manufacturing an internally threaded pipe includes the following steps performed sequentially:

[0060] S1. Raw material stacking: Stack the steel strip raw materials in the raw material stacking area for later use;

[0061] S2, Dual-head feeding: The steel strip is fed continuously by alternating feeding through the dual-head feeding disc 1;

[0062] S3. Steel strip cleaning: After the steel strip is unloaded, it is sent into the steel strip cleaning water tank 2 to clean the surface of the steel strip and remove oil and impurities.

[0063] S4. Internal thread cutting: Using the thread cutting device 3, the required thread line is cut on the surface of the steel strip;

[0064] S5. Forming and Welding: The cleaned steel strip is gradually rolled into a round tube shape by the forming unit 4, and the joint is welded to form a straight seam welded pipe.

[0065] S6. Internal leveling: The internal leveling device 5 is used to level the inner wall of the welded pipe to eliminate the protrusions on the inner wall of the weld.

[0066] S7. Weld polishing and initial sizing: The weld polishing and initial sizing device 6 is used to polish the outer weld of the pipe so that the weld is flush with the outer wall of the pipe. At the same time, the pipe is initially sized to obtain the preliminary outer diameter.

[0067] S8. Online bright annealing: The pre-sized pipe is sent into the online bright annealing device 7 and bright annealed under a protective atmosphere to eliminate internal stress.

[0068] S9. Precision sizing: The precision sizing device 8 is used to precisely sizing the annealed pipe to make the outer diameter of the pipe meet the tolerance range required by the finished product.

[0069] S10, Servo sawing: The pipe cutting machine 9 with dual servo saw blades cuts the pipe to a set length.

[0070] S11. Automatic sorting: The cut pipes are sorted by the automatic sorting rack 10 according to their quality status and specifications.

[0071] S12, Coiling: The sorted qualified pipes are coiled into a coil shape by the coiling machine 11.

[0072] S13. Inspection and Packaging: The coiled pipe is sent to the coil inspection and packaging area for final inspection, weighing, bundling and packaging to obtain the finished internally threaded pipe.

[0073] By setting up thirteen continuous process steps from start to finish, and integrating double-head feeding, online cleaning, internal thread cutting, laser welding, online bright annealing, and servo sawing, fully automated continuous production of internal threaded tubes is achieved, which greatly improves production efficiency and product consistency.

[0074] refer to Figures 4-8 In order to achieve continuous and stable forming of steel strip into straight seam welded pipe, each segment works in coordination to reduce pipe blank twisting and weld offset. Forming unit 4 in S4 includes a feeding guide section, a roller pre-forming section, a closed forming section, a weld centering section, a laser welding section and a discharge cooling section arranged sequentially along the pipe traveling direction.

[0075] In order to obtain weld position information in real time and automatically adjust the welding head posture to achieve high-precision weld tracking, the laser welding section includes a support 12. The inner top surface of the support 12 is equipped with a laser welding machine 13, an adjustment mechanism for adjusting the laser welding machine 13, and a weld visual tracking sensor assembly.

[0076] To directly link visual perception with the actuator and shorten the control response time, the weld seam visual tracking sensor assembly includes a laser structured light generator 15 and a high-speed industrial camera 16. The laser structured light generator 15 projects laser stripes onto the weld seam area of ​​the tube blank, and the high-speed industrial camera 16 acquires images of the weld seam area. The high-speed industrial camera 16 has a built-in image processing module that extracts the weld seam center position and weld seam gap width. The output of the image processing module is connected to the adjustment mechanism.

[0077] refer to Figure 3 To improve the dynamic performance of weld seam tracking, the image processing module uses the Kalman filter algorithm to predict the weld seam offset and gap width at the next moment, generates a feedforward compensation signal, and establishes a Kalman filter state-space model: , ,in, for The state vector at time t, Here is the state transition matrix. for The state vector at time t, For the input control matrix, for The control input vector at time t, For process noise, for The observation vector at time t, For the observation matrix, To observe noise.

[0078] To achieve independent control of the weld position and gap width, the image processing module receives the weld offset and gap width predicted by Kalman filtering at the next moment via a multivariable adaptive fuzzy PID controller. It then calculates the correction amount of the PID parameters online using a fuzzy rule base to obtain the real-time PID parameters. Finally, it generates the final control output by combining the feedforward compensation signal, as shown in the formula: , , , ,in, This refers to the lateral offset deviation of the weld. Set a value for the lateral offset of the weld. This is the measured value of the lateral offset of the weld. This refers to the deviation in weld gap width. Set a value for the weld gap width. This is the measured value of the weld gap width. This represents the rate of change of the lateral offset deviation of the weld. This represents the lateral offset deviation of the weld at the previous moment. The sampling period is This represents the rate of change of weld gap width deviation. This represents the deviation in weld gap width at the previous moment.

[0079] By setting up a weld seam visual tracking sensor assembly and combining it with a Kalman filter feedforward prediction algorithm and a multivariable adaptive fuzzy PID controller, the weld seam offset and gap width can be predicted and compensated in advance, which significantly reduces the welding defect rate and ensures the stability of welding quality.

[0080] To achieve precise horizontal translation of the laser welding machine 13, the adjustment mechanism includes two mounting slots 14 formed on the inner top surface of the support 12. The laser structured light generator 15 and the high-speed industrial camera 16 are both mounted on the inner top surface of the support 12. Miniature hydraulic cylinders 141 are installed on the inner walls of the two mounting slots 14. One end of the piston rod of the two miniature hydraulic cylinders 141 is fixedly connected to a connecting plate 142. The laser welding machine 13 is set on the side surface of the connecting plate 142 away from the mounting slots 14. The extension and retraction of the piston rod of the miniature hydraulic cylinder 141 drives the connecting plate 142 connected to it to move, thereby driving the laser welding machine 13 to move.

[0081] To improve the guiding accuracy and torsional resistance of the connecting plate 142 during movement, limit rods 143 are fixedly connected to the inner walls of both mounting slots 14. The inner wall of the connecting plate 142 is slidably connected to the surface of the limit rods 143, and the surface of the connecting plate 142 is slidably engaged with the inner wall of the mounting slot 14. The moving plate can move horizontally through the mounting slots 14 and the limit rods 143.

[0082] In order to achieve independent vertical adjustment of the laser welding machine 13, a lifting hydraulic cylinder 144 is provided between the connecting plate 142 and the laser welding machine 13. One end of the piston rod of the lifting hydraulic cylinder 144 is fixedly connected to the laser welding machine 13. The extension and retraction of the piston rod of the lifting hydraulic cylinder 144 drives the laser welding machine 13 connected to it to move.

[0083] To avoid interference with the operation, electromagnets 145 are provided on the opposite side surfaces of the two connecting plates 142 and the lifting hydraulic cylinder 144. When the two electromagnets 145 are energized, they attract each other. The laser welding machine 13 needs to be moved to the left or right so that the electromagnets 145 on the corresponding connecting plate 142 and the electromagnets 145 on the lifting hydraulic cylinder 144 are energized and attracted, while the electromagnets 145 on the other connecting plate 142 are de-energized.

[0084] By setting an adjustment mechanism, the laser welding machine 13 can be adjusted with high precision and quick separation in both horizontal and vertical directions, which not only meets the centering requirements in production, but also facilitates equipment maintenance.

[0085] Working principle: such as Figures 1-16As shown, when in use, the steel strip raw material is taken from the raw material stacking area. The steel strip is fed through the double-headed feeding tray 1, and after being cleaned in the steel strip cleaning water tank 2, the thread cutting device 3 cuts the thread line on the surface of the steel strip, and then it enters the forming unit 4 to be gradually rolled into a round tube.

[0086] The laser welding section of the forming unit 4 collects the weld offset and gap width in real time through the weld visual tracking sensor. The Kalman filter algorithm is used to make the optimal prediction of the weld state at the next moment to generate a feedforward compensation signal. At the same time, the multivariable adaptive fuzzy PID controller is combined to tune the PID parameters online and superimpose the feedforward quantity to drive the micro hydraulic cylinder 141 and the lifting hydraulic cylinder 144 to precisely adjust the position of the laser welding machine 13, so as to realize high-precision dynamic tracking of the weld and welding gap control.

[0087] When the laser welding machine 13 needs to be moved horizontally to the left or right, the electromagnet 145 on the corresponding moving connecting plate 142 and the electromagnet 145 on the lifting hydraulic cylinder 144 are kept energized, while the electromagnet 145 on the other connecting plate 142 is de-energized. As the piston rod of the micro hydraulic cylinder 141 extends and retracts, it drives the connecting plate 142 connected to it to move along the inner wall of the mounting groove 14 and the surface of the limit rod 143, thereby driving the lifting hydraulic cylinder 144 and the laser welding machine 13 to move horizontally left and right, and using the lifting hydraulic cylinder 144 to drive the laser welding machine 13 to approach the weld.

[0088] After welding, the pipes are sequentially processed by an internal leveling device 5, a weld polishing and initial sizing device 6, an online bright annealing device 7, a fine sizing device 8, a dual servo saw blade pipe cutter 9, an automatic sorting rack 10, a coiling machine 11, and inspection and packaging, ultimately yielding a finished internally threaded pipe with a smooth inner wall, stable weld quality, and high dimensional accuracy.

[0089] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A process for manufacturing internally threaded pipes, characterized in that, The following steps are performed sequentially: S1. Raw material stacking: Stack the steel strip raw materials in the raw material stacking area for later use; S2, Double-headed feeding: The steel strip is fed continuously by alternating feeding through the double-headed feeding disc (1); S3. Steel strip cleaning: After the steel strip is unloaded, it is sent into the steel strip cleaning water tank (2) to clean the surface of the steel strip and remove oil and impurities. S4. Internal thread cutting: Using a thread cutting device (3), the required thread line is cut on the surface of the steel strip; S5. Forming and welding: The cleaned steel strip is gradually rolled into a round tube by the forming unit (4) and welded to the joint to form a straight seam welded pipe. S6. Internal leveling: The internal leveling device (5) is used to level the inner wall of the welded pipe to eliminate the protrusions on the inner wall of the weld. S7. Weld polishing and initial sizing: The weld of the pipe is polished using the weld polishing and initial sizing device (6) so that the weld is flush with the outer wall of the pipe. At the same time, the pipe is initially sized to obtain the initial outer diameter. S8. Online bright annealing: The pipe after preliminary sizing is sent into the online bright annealing device (7) and bright annealed under a protective atmosphere to eliminate internal stress. S9. Precision sizing: The annealed pipe is precisely sized using a precision sizing device (8) so that the outer diameter of the pipe meets the tolerance range required by the finished product. S10, Servo sawing: The pipe is cut to length according to the set length using a dual servo saw blade pipe cutter (9); S11. Automatic sorting: The cut pipes are sorted by quality status and specifications by the automatic sorting rack (10); S12, coiling: The sorted qualified pipes are coiled into a coil shape by the coiling machine (11); S13. Inspection and Packaging: The coiled pipe is sent to the coil inspection and packaging area for final inspection, weighing, bundling and packaging to obtain the finished internally threaded pipe.

2. The manufacturing process for an internally threaded pipe according to claim 1, characterized in that: The forming unit (4) described in S4 includes a feeding guide section, a roller preforming section, a closed forming section, a weld alignment section, a laser welding section and a discharge cooling section arranged sequentially along the pipe traveling direction.

3. The manufacturing process for an internally threaded pipe according to claim 2, characterized in that: The laser welding section includes a bracket (12), on the inner top surface of which a laser welding machine (13), an adjustment mechanism for adjusting the laser welding machine (13), and a weld visual tracking sensor assembly are disposed.

4. The manufacturing process for an internally threaded pipe according to claim 3, characterized in that: The weld seam visual tracking sensor assembly includes a laser structured light generator (15) and a high-speed industrial camera (16). The laser structured light generator (15) projects laser stripes onto the weld seam area of ​​the tube blank. The high-speed industrial camera (16) acquires images of the weld seam area. The high-speed industrial camera (16) has a built-in image processing module. The image processing module extracts the weld seam center position and weld seam gap width. The output end of the image processing module is connected to the adjustment mechanism.

5. The manufacturing process for an internally threaded pipe according to claim 4, characterized in that: The image processing module uses the Kalman filter algorithm to predict the weld offset and gap width at the next moment, generates a feedforward compensation signal, and establishes a Kalman filter state-space model. , ,in, for The state vector at time t, Here is the state transition matrix. for The state vector at time t, For the input control matrix, for The control input vector at time t, For process noise, for The observation vector at time t, For the observation matrix, To observe noise.

6. The manufacturing process for an internally threaded pipe according to claim 5, characterized in that: The image processing module receives the weld offset and gap width predicted by Kalman filtering at the next moment via a multivariable adaptive fuzzy PID controller, and calculates the correction amount of the PID parameters online using a fuzzy rule base to obtain the real-time PID parameters. Finally, it generates the final control output by combining the feedforward compensation signal, as shown in the formula: , , , ,in, This refers to the lateral offset deviation of the weld. Set a value for the lateral offset of the weld. This is the measured value of the lateral offset of the weld. This refers to the deviation in weld gap width. Set a value for the weld gap width. This is the measured value of the weld gap width. This represents the rate of change of the lateral offset deviation of the weld. This represents the lateral offset deviation of the weld at the previous moment. The sampling period is This represents the rate of change of weld gap width deviation. This represents the deviation in weld gap width at the previous moment.

7. The manufacturing process for an internally threaded pipe according to claim 4, characterized in that: The adjustment mechanism includes two mounting slots (14) formed on the inner top surface of the bracket (12). The laser structured light generator (15) and the high-speed industrial camera (16) are both mounted on the inner top surface of the bracket (12). Miniature hydraulic cylinders (141) are installed on the inner walls of the two mounting slots (14). One end of the piston rod of the two miniature hydraulic cylinders (141) is fixedly connected to a connecting plate (142). The laser welding machine (13) is located on the side surface of the connecting plate (142) away from the mounting slots (14).

8. The manufacturing process for an internally threaded pipe according to claim 7, characterized in that: The inner walls of both mounting slots (14) are fixedly connected to limit rods (143), the inner wall of the connecting plate (142) is slidably connected to the surface of the limit rods (143), and the surface of the connecting plate (142) is slidably engaged with the inner wall of the mounting slots (14).

9. The manufacturing process of an internally threaded pipe according to claim 7, characterized in that: A lifting hydraulic cylinder (144) is provided between the connecting plate (142) and the laser welding machine (13), and one end of the piston rod of the lifting hydraulic cylinder (144) is fixedly connected to the laser welding machine (13).

10. The manufacturing process of an internally threaded pipe according to claim 9, characterized in that: Electromagnets (145) are provided on the opposite side surfaces of the two connecting plates (142) and the lifting hydraulic cylinder (144), and the two electromagnets (145) attract each other when energized.

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