Large-diameter steel pipe butt welding device and method

Abstract

The invention discloses a large-diameter steel pipe butt welding device and method, and belongs to the technical field of steel pipe welding.The large-diameter steel pipe butt welding device comprises a welding mechanism, limiting mechanisms are arranged on the two sides of the welding mechanism, the welding mechanism comprises a supporting ring arranged between the two limiting mechanisms, and the bottom of the supporting ring is fixed to the top of a supporting seat; an annular rotating groove is formed in the inner circle of the supporting ring and connected with a sliding ring in a sliding fit mode, the sliding ring is fixedly connected with one side of a movable plate through a telescopic rod, and a welding gun and a grinding assembly are fixedly arranged on the other side of the movable plate. The problems that traditional large-diameter steel pipe welding is low in positioning precision and uneven in weld joint treatment are solved.

Description

Technical Field

[0001] The invention relates to the technical field of steel pipe welding, in particular to a large-diameter steel pipe butt welding device and method. Background Art

[0002] Large-diameter steel pipes are widely used in the fields of oil and gas transportation and large-scale construction projects. As an important material in the industrial field, its specifications and sizes are diverse and widely used. Generally speaking, the diameter of such steel pipes exceeds 159mm and the wall thickness is greater than 4.0mm. The specific range can reach a diameter of 219mm to 3620mm and a wall thickness of 6mm to 30mm. However, in actual engineering applications, the length of a single steel pipe often cannot meet the needs of the overall project. Therefore, during the laying and installation of steel pipes, multiple sections of steel pipes need to be butt-jointed and circumferentially welded at the joints to fix the two butt-jointed steel pipes together.

[0003] The prior art has the following problems when butt welding large-diameter steel pipes: 1. Due to the large size and heavy weight of large-diameter steel pipes, traditional methods usually rely on manual operation and complex mechanical equipment. This method is not only labor-intensive and inefficient, but also the accuracy is often difficult to effectively guarantee when positioning and aligning the steel pipes. This inaccurate positioning problem will directly affect the subsequent welding process, and may lead to a series of quality problems such as uneven welds and insufficient welding strength.

[0004] 2. There are often impurities such as rust, oil, and oxide layer on the surface of steel pipes. If not handled properly, it will seriously affect the quality and firmness of welding. Traditional cleaning methods are mostly manual grinding, which is not only labor-intensive, but also difficult to ensure the consistency and uniformity of weld treatment. Summary of the invention

[0005] The purpose of the present invention is to overcome the above-mentioned shortcomings and provide a large-diameter steel pipe butt welding device and method to solve the problems of low positioning accuracy and uneven weld processing in traditional large-diameter steel pipe welding.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is: a large-diameter steel pipe butt welding device, including a welding mechanism, limiting mechanisms are provided on both sides of the welding mechanism, the welding mechanism includes a support ring arranged between two groups of limiting mechanisms, the bottom of the support ring is fixed to the top of the support seat, the inner ring of the support ring is provided with an annular rotation groove, the annular rotation groove is slidably connected with the sliding ring, the sliding ring is fixedly connected to one side of the movable plate through a telescopic rod, and a welding gun and a grinding assembly are fixedly provided on the other side of the movable plate.

[0007] Preferably, the grinding assembly is provided with two groups and is symmetrically distributed on both sides of the welding gun; the grinding assembly includes an articulated seat, one end of which is hinged to the movable plate through a hinge joint, and the other end cooperates with the grinding motor, and the output shaft of the grinding motor is fixedly connected to the rotating brush head.

[0008] Preferably, the grinding assembly also includes a fixed sleeve and a movable sliding rod, one end of the fixed sleeve is fixedly connected to the other end of the hinged seat, the other end of the fixed sleeve is slidably matched with one end of the movable sliding rod, and the other end of the movable sliding rod is fixedly connected to the grinding motor; a spring is also provided between the inner side of the fixed sleeve and the end of the movable sliding rod.

[0009] Preferably, the welding mechanism also includes a bracket and a driving gear, the top of the support ring is provided with a slot connected to the annular rotating groove, the bracket is fixedly arranged at the notch of the slot, the driving gear is rotationally matched with the bracket, and the side of the sliding ring is provided with a tooth groove meshing with the driving gear; the center of the driving gear is fixedly connected to the output shaft of the rotating motor, and the rotating motor is fixedly connected to the bracket.

[0010] Preferably, a spacing sensor and a visual detection module are also fixedly provided on the movable plate, the spacing sensor is electrically connected to the controller of the telescopic rod, and the visual detection module is connected to the controller of the rotating motor.

[0011] Preferably, the limiting mechanism includes a base, a symmetrically arranged limiting frame is fixedly provided on the top of the base, and the limiting frame is provided with an inclined surface; one of the bases is provided with a laser transmitter, and the other base is provided with a laser receiver; the limiting mechanism also includes a universal wheel, a plurality of universal wheels are provided, and are arranged in a matrix on the electric telescopic rod at the bottom of the base, a pressure sensor is provided between the bottom of the base and the top of the electric telescopic rod, and the pressure sensor is connected to the controller of the electric telescopic rod.

[0012] Preferably, a plurality of groups of self-aligning support assemblies are evenly arranged along the circumferential direction at the edge positions on both sides of the inner wall of the support ring, and each group of the self-aligning support assemblies includes a mounting seat fixed to the inner ring of the support ring, and the mounting seat is connected to the support wheel frame through a ball joint, and a support roller is rotatably mounted on the support wheel frame; the rolling surface of the support roller is an inwardly concave arc surface adapted to the outer wall of the steel pipe, and a reset spring is connected between the support wheel frame and the mounting seat, and the reset spring always applies an elastic force toward the axis of the steel pipe to the support wheel frame; an angle sensor is also provided at the ball joint or the support wheel frame for calculating the offset of the axis of the steel pipe, and the angle sensor is connected to the controller of the rotating motor.

[0013] In addition, the present invention also discloses a welding method of the above-mentioned large-diameter steel pipe butt welding device, comprising the following steps: Step S1: Place the two sections of large-diameter steel pipes to be welded on the top of the bases of the two sets of limit mechanisms respectively; during this process, the position accuracy of the base is monitored in real time through the cooperation of the laser transmitter and the laser receiver; if the laser receiver cannot receive the laser signal, the system automatically issues an alarm to prompt the operator to adjust the position of the base until the laser receiver accurately receives the signal, thereby ensuring the accuracy of the initial placement of the two sections of steel pipes; Step S2: insert one end of the two steel pipes to be welded into the inner ring of the support ring by moving the base; in this process, dynamically align the steel pipe using the aligning support components evenly arranged circumferentially on the inner wall of the support ring; when the steel pipe is inserted, the support rollers adaptively open outward and fit the outer wall of the steel pipe under the action of the reset spring, and the ball joint allows the support wheel frame to rotate in three-dimensional space to adapt to the ovality deviation of the steel pipe caused by its own weight or processing error, and calibrate the axis of the steel pipe in real time until the axes of the two steel pipes are completely overlapped and the ends are in contact with each other; During the dynamic centering of the steel pipe by the centering support assembly, the pressure sensor at the bottom of the base detects the load-bearing condition of the base in real time. If the load-bearing condition exceeds the preset value, the controller controls the electric telescopic rod to retract. If the load-bearing condition is less than the preset value, the controller controls the electric telescopic rod to extend, so that the load-bearing condition of the base is always kept within the preset range. Finally, during the real-time calibration of the steel pipe axis by the centering support assembly, the base can adjust the base height in real time according to the pressure change, so that the steel pipe can always be close to the surface of the base. At the same time, during the real-time calibration of the steel pipe axis by the centering support assembly, if the steel pipe is laterally displaced in the horizontal direction, the movement and adjustment process of the base in the horizontal plane is directly realized by the movement of its universal wheels. Through the above process, the adjustment of the base position always follows the real-time calibration of the steel pipe axis by the centering support assembly. After the self-aligning support assembly completes the dynamic self-aligning process of the steel pipe, the brake system of the universal wheel is locked to keep the base stationary; Step S3: Start the telescopic rod. At this time, the distance sensor on the movable plate monitors the distance between the movable plate and the steel pipe in real time. The controller of the telescopic rod accurately adjusts the telescopic length of the telescopic rod according to the signal fed back by the distance sensor, so that the distance between the movable plate and the steel pipe is always kept within the set optimal distance range, ensuring that the welding gun and the grinding assembly can be in the best working position. Step S4: first start a set of grinding components and a rotating motor. During the rotation of the sliding ring, the grinding components grind the surface of the steel pipe to be welded. Then start the welding gun and another set of grinding components, so that the welding gun and the grinding components can continuously perform the annular welding process along the butt gap of the steel pipe.

[0014] Preferably, step S4 includes the following process: Step S4.1, first grinding: start the left assembly of the two symmetrically arranged grinding assemblies, and rotate the sliding ring forward at the initial speed to make the grinding assembly move in a circular motion along the outer wall of the steel pipe; The grinding assembly adaptively fits the curved surface of the steel pipe through the hinged joint and the hinged seat, and the movable slide bar and the spring provide the initial contact pressure to ensure that the rotating brush head fits tightly against the surface of the steel pipe; If the distance sensor detects that the distance between the movable plate and the steel pipe surface fluctuates beyond the preset safety threshold, the controller controls the telescopic rod to automatically fine-tune, and at the same time the movable slide bar of the grinding component slides in the fixed sleeve, and the pressure of the rotating brush head is maintained stable through spring elastic compensation; After each round of grinding, the visual inspection module performs a 360° scan of the grinding area and identifies residual oxide layers or oil stains through image grayscale analysis. If a substandard area is detected, that is, the grayscale value exceeds the standard range, the system marks the coordinates of the area, and the sliding ring re-scans the area at a lower speed in subsequent rotations, while grinding the motor power boost part until the inspection is qualified. S4.2, Steering compensation under abnormal working conditions: The deviation of the steel pipe axis is calculated by the swing angle of the ball joint of the support wheel frame in the self-aligning support assembly. When the deviation of the steel pipe axis exceeds the threshold, the brake system of the universal wheel is unlocked, and then a "compensation steering pulse" of a certain angle is automatically inserted during the rotation of the sliding ring, that is, the original direction is restored after a short reverse rotation, ensuring that the grinding track is always evenly distributed along the circumference of the steel pipe, and then the brake system of the universal wheel is re-locked; S4.3, Sliding ring forward and reverse strategy and path planning: During the base welding, the sliding ring rotates forward at a low speed, and the grinding assembly in front of the welding gun rotates forward synchronously to remove residual impurities; When welding the cover, the sliding ring reverses at high speed, and another set of grinding components follows to grind the weld surface; When the visual inspection module identifies the weld undercut defect, the sliding ring pauses in front of the defect location and welds back and forth slightly.

[0015] Preferably, in step S4.2, automatically inserting a "compensation steering pulse" of a certain angle during the rotation of the slip ring specifically includes the following process: Offset judgment and pulse triggering: The swing angle of the support wheel frame is monitored in real time through the angle sensor installed on the support wheel frame or the ball joint. If the swing angle exceeds the threshold, it means that the self-aligning support component has not calibrated the steel pipe axis and the offset of the steel pipe axis exceeds the preset allowable range. At this time, the compensating steering pulse mechanism is immediately triggered; Pulse angle calculation: The system selects the angle of the steering pulse that needs to be compensated according to the degree of deviation. The greater the deviation, the greater the angle of the steering pulse required to be compensated. Pulse execution process: During normal rotation, the sliding ring immediately suspends the current rotation direction after receiving the compensation steering pulse command; then it briefly rotates in the opposite direction according to the corresponding pulse angle; specifically, if the sliding ring is currently in the forward rotation state, it will rotate in the opposite direction by a certain pulse angle after receiving the pulse command; during the reverse rotation process, the friction between the grinding component and the surface of the steel pipe will push the steel pipe with the axis offset in the opposite direction to cause it to shake, and then the axis of the steel pipe will be adaptively adjusted through the self-aligning support component; after the reverse rotation is completed, the sliding ring quickly returns to the original rotation direction and continues the grinding operation; Multiple pulse compensation: If the self-aligning support assembly detects that the steel pipe axis is still offset after one compensation steering pulse, the system will trigger the compensation steering pulse again; through multiple pulse compensation, the steel pipe axis is gradually adjusted to the allowable error range.

[0016] Beneficial effects of the present invention: 1. The present invention realizes accurate positioning, rapid alignment and high-quality annular welding of steel pipes through a limiting mechanism and a welding mechanism, and solves the problems of low positioning accuracy and uneven weld processing in traditional large-diameter steel pipe welding.

[0017] 2. The device of the present invention utilizes an inclined surface to guide the steel pipe to slide into a predetermined position, thereby simplifying the placement process and improving positioning accuracy; at the same time, through the flexible cooperation of the telescopic rod and the sliding ring, the precise movement and rotation of the welding gun and the grinding assembly are realized, thereby ensuring the uniformity and firmness of the weld and significantly improving the welding efficiency and quality.

[0018] 3. The sensor of the present invention can detect the welding quality of large-diameter water-transporting steel pipes. A display is fixedly connected to the side end of the guide rail, and the sensor transmits the detected data to the display for display.

[0019] 4. The present invention sets a self-aligning support assembly with a ball joint and a reset spring on the inner wall of the support ring, and the arc-shaped rolling surface of the support roller is adapted to the outer wall of the steel pipe to form an elastic support structure that can be adaptively adjusted. In the prior art, the positioning of steel pipes mainly relies on the inclined surface of the limit frame and the laser centering system, and lacks dynamic self-aligning capabilities for large-diameter steel pipes with ovality deviations caused by their own weight or processing errors. The structure of the present invention allows the support wheel frame to rotate freely in three-dimensional space through the ball joint. With the elastic force of the reset spring, when the steel pipe enters along the axial direction, the support roller can adaptively open outward under the action of the reset spring, and automatically fit the outer wall of the steel pipe to achieve dynamic calibration of the steel pipe axis. At the same time, the limiting effect of multiple support rollers can also prevent the steel pipe from radial displacement during welding and grinding, solving the problem that traditional rigid supports cannot adapt to the deviation of the steel pipe shape, significantly improving the matching accuracy, and reducing welding defects caused by axis offset.

[0020] 5. During the grinding process, when the axis deviation of the steel pipe exceeds a threshold value, a "compensation steering pulse" of a certain angle is automatically inserted during the rotation of the sliding ring, that is, the original direction is restored after a short reverse rotation, which can ensure that the grinding track is always evenly distributed along the circumference of the steel pipe.

[0021] 6. The sliding ring in the present invention is slidably connected with the annular groove of the support ring, which enables the welding gun and the grinding assembly to continuously perform annular welding and grinding processes along the butt gap of the steel pipe, greatly improving the welding efficiency; in addition, through the rotation of the sliding ring, the weld is ensured to be uniform and firm, achieving high-quality welding connection. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a three-dimensional structural schematic diagram of a large-diameter steel pipe butt welding device; Figure 2 It is a three-dimensional structural schematic diagram of the welding mechanism in the present invention; Figure 3 It is a three-dimensional structural schematic diagram of the grinding assembly in the present invention; Figure 4 is a structural cross-sectional view of the grinding assembly of the present invention; Figure 5 It is a three-dimensional structural schematic diagram of the limiting mechanism in the present invention; Figure 6 This is a schematic diagram of the structure after the self-aligning support assembly is installed on the inner wall of the support ring; Figure 7 It is a schematic diagram of the enlarged structure of the area where the support roller is located; In the figure, 1. limit mechanism; 2. welding mechanism; 3. base; 4. limit frame; 5. inclined plane; 6. support ring; 7. sliding ring; 8. telescopic rod; 9. movable plate; 10. welding gun; 11. grinding assembly; 12. support seat; 13. annular groove; 14. hinge head; 15. hinge seat; 16. grinding motor; 17. rotating brush head; 18. fixed sleeve; 19. movable slide rod; 20. spring; 21. bracket; 22. driving gear; 23. tooth groove; 24. rotating motor; 25. spacing sensor; 26. laser transmitter; 27. laser receiver; 28. universal wheel; 29. ​​self-aligning support assembly; 291. mounting seat; 292. ball joint; 293. support wheel frame; 294. support roller; 295. reset spring. DETAILED DESCRIPTION

[0023] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0024] Example 1: Figure 1-7As shown, a large-diameter steel pipe butt welding device includes a welding mechanism 2, and limiting mechanisms 1 are provided on both sides of the welding mechanism 2. The welding mechanism 2 includes a support ring 6 arranged between two groups of limiting mechanisms 1, and the bottom of the support ring 6 is fixed to the top of the support seat 12. The inner circle of the support ring 6 is provided with an annular groove 13, and the annular groove 13 is slidably connected with the sliding ring 7. The sliding ring 7 is fixedly connected to one side of the movable plate 9 through a telescopic rod 8, and the other side of the movable plate 9 is fixedly provided with a welding gun 10 and a grinding assembly 11.

[0025] In this embodiment, first, the two sections of large-diameter steel pipes to be welded are hoisted to the top of the base 3 of the two sets of limiting mechanisms 1. The top of the limiting frame 4 is provided with an inclined surface 5, which helps to guide the steel pipe to slide into the predetermined position in the limiting frame 4, thereby reducing the difficulty and deviation probability of steel pipe placement and improving positioning efficiency. By moving the base 3, the ends of the two sections of steel pipes to be welded are inserted into the inner ring of the support ring 6 until the axes of the two sections of steel pipes coincide, completing the alignment and fixing preparation of the steel pipes.

[0026] Then, the telescopic rod 8 is started to keep the distance between the movable plate 9 and the steel pipe within the set distance, and the welding gun 10 and the grinding assembly 11 are moved to the outside of the steel pipe. The two sets of grinding assemblies 11 are started successively to grind the surface of the steel pipe welding part twice. The first grinding is to remove impurities such as rust, oil stains, and oxide layers to create good basic conditions for subsequent welding operations. The second grinding is to remove impurities generated during the welding process.

[0027] The sliding ring 7 is slidably connected with the annular groove 13 of the support ring 6, so that the welding gun 10 and the grinding assembly 11 can continuously perform the annular welding and grinding process along the butt joint gap of the steel pipe. Through the rotation of the sliding ring 7, the weld is ensured to be uniform and firm, and a high-quality welding connection is achieved.

[0028] The present invention realizes accurate positioning, rapid alignment and high-quality annular welding of steel pipes through the limiting mechanism 1 and the welding mechanism 2. The device uses the inclined surface 5 to guide the steel pipe to slide into the predetermined position, which simplifies the placement process and improves the positioning accuracy; at the same time, through the flexible cooperation of the telescopic rod 8 and the sliding ring 7, the precise movement and rotation of the welding gun 10 and the grinding assembly 11 are realized, thereby ensuring the uniformity and firmness of the weld, and significantly improving the welding efficiency and quality.

[0029] refer to Figure 3 As shown, the grinding assembly 11 is provided with two groups and is symmetrically distributed on both sides of the welding gun 10; the grinding assembly 11 includes an articulated seat 15, one end of the articulated seat 15 is hinged to the movable plate 9 through a hinge head 14, and the other end cooperates with the grinding motor 16, and the output shaft of the grinding motor 16 is fixedly connected to the rotating brush head 17.

[0030] When the grinding motor 16 is started, the motor drives the rotating brush head 17 to rotate at high speed. Since the hinge seat 15 can be flexibly rotated through the hinge head 14, the grinding angle can be adaptively adjusted according to the actual situation of the steel pipe surface to ensure that the rotating brush head 17 is in full contact with the steel pipe surface.

[0031] This adjustable angle design enables the grinding assembly 11 to better fit the curved surface of the large-diameter steel pipe, and can achieve efficient and comprehensive grinding regardless of the curvature change or the flat part of the steel pipe, thereby greatly improving the grinding quality and reducing welding defects caused by insufficient grinding.

[0032] refer to Figure 3 As shown, the grinding assembly 11 also includes a fixed sleeve 18 and a movable slide rod 19, one end of the fixed sleeve 18 is fixedly connected to the other end of the hinged seat 15, the other end of the fixed sleeve 18 is slidably matched with one end of the movable slide rod 19, and the other end of the movable slide rod 19 is fixedly connected to the grinding motor 16; a spring 20 is also provided between the inner side of the fixed sleeve 18 and the end of the movable slide rod 19.

[0033] When the grinding motor 16 is started and drives the rotating brush head 17 to grind the steel pipe, if the surface of the steel pipe is uneven or has protrusions, the movable slide rod 19 can automatically retract in the fixed sleeve 18 to maintain a stable contact pressure between the rotating brush head 17 and the surface of the steel pipe.

[0034] This enables the grinding assembly 11 to have certain buffering and adaptive capabilities, avoiding overloading of the grinding motor 16 or damage to the rotating brush head 17 due to the uneven surface of the steel pipe, extending the service life of the grinding assembly 11, while ensuring the consistency of the grinding effect and improving the stability of the grinding operation.

[0035] refer to Figure 4 As shown, during the grinding process, the spring 20 plays a role in buffering and regulating pressure. When the rotating brush head 17 contacts the surface of the steel pipe, the spring 20 will automatically compress or stretch according to the contact pressure, ensuring that the rotating brush head 17 always acts on the surface of the steel pipe with appropriate pressure. Specifically, the setting of the spring 20 further enhances the adaptability of the grinding assembly 11 to the uneven surface of the steel pipe, and can prevent damage to the surface of the steel pipe due to excessive pressure while ensuring the grinding effect, thereby improving the safety and reliability of grinding, and helping to evenly remove impurities and oxide layers on the surface of the steel pipe.

[0036] refer to Figure 2As shown, the welding mechanism 2 also includes a bracket 21 and a driving gear 22. The top of the support ring 6 is provided with a slot connected to the annular rotating groove 13. The bracket 21 is fixedly arranged at the notch of the slot. The driving gear 22 is rotatably connected to the bracket 21. The side of the sliding ring 7 is provided with a tooth groove 23 meshing with the driving gear 22. The center of the driving gear 22 is fixedly connected to the output shaft of the rotating motor 24, and the rotating motor 24 is fixedly connected to the bracket 21.

[0037] The rotating motor 24 can accurately control the rotation speed of the driving gear 22, so as to flexibly adjust the moving speed of the welding gun 10 according to the welding process requirements, realize accurate control of different welding parameters, improve the flexibility and adaptability of welding operations, and meet diverse welding needs. When the driving gear 22 rotates, the tooth groove 23 drives the sliding ring 7 to make a circular motion in the annular rotating groove 13, thereby driving the entire welding assembly to weld around the steel pipe.

[0038] Specifically, the meshing transmission between the driving gear 22 and the tooth groove 23 of the sliding ring 7 can provide a stable and precise circular motion driving force, ensure the precise motion trajectory of the welding gun 10 during welding, make the weld uniform and firm, and improve the welding quality and consistency.

[0039] refer to Figure 3 As shown, a spacing sensor 25 and a visual detection module are also fixedly provided on the movable plate 9 . The spacing sensor 25 is electrically connected to the controller of the telescopic rod 8 , and the visual detection module is connected to the controller of the rotating motor 24 .

[0040] When a change in distance is detected, the spacing sensor 25 transmits a signal to the controller of the telescopic rod 8, and the telescopic rod 8 automatically adjusts the telescopic length according to the signal to keep the distance between the welding gun 10 and the surface of the steel pipe constant.

[0041] The distance sensor 25 can ensure that the welding gun 10 always maintains a suitable distance from the steel pipe surface during welding, which is crucial to ensure the stability of welding current and voltage, as well as the stability of welding quality. It can effectively avoid welding defects caused by distance changes, such as cold welding and welding penetration, and significantly improve welding quality.

[0042] More preferably, the welding mechanism 2 also includes a visual inspection module arranged on the movable plate 9, and the visual inspection module includes an industrial camera and an image processing unit; the industrial camera is arranged toward the butt joint gap of the steel pipe for real-time acquisition of the weld image; the image processing unit is electrically connected to the control system of the welding gun, and can automatically adjust the welding current, welding speed and welding rod angle of the welding gun according to the weld image. The existing welding process relies on spacing sensors and manually preset parameters, and cannot cope with dynamic changes such as irregular weld grooves and welding thermal deformation. This structure introduces machine vision technology into the welding device, so that the equipment has autonomous perception and decision-making capabilities: the industrial camera captures key information such as weld contours and molten pool morphology in real time, and the image processing unit calculates the optimal welding parameters such as current size and welding rod angle through an algorithm, and feeds back to the welding gun control system in real time, forming a closed-loop control of "detection-analysis-adjustment". This technical solution breaks through the open-loop control mode of traditional welding devices, significantly improves the stability of welding quality, and is particularly suitable for variable grooves and variable gap conditions commonly seen in large-diameter steel pipe welding.

[0043] refer to Figure 5 As shown, the limiting mechanism 1 includes a base 3, the top of which is fixedly provided with a symmetrically arranged limiting frame 4, and the limiting frame 4 is provided with an inclined surface 5; one of the bases 3 is provided with a laser transmitter 26, and the other base 3 is provided with a laser receiver 27; the limiting mechanism 1 also includes a universal wheel 28, and the universal wheel 28 is provided in a plurality and arranged in a matrix on the electric telescopic rod 3.1 at the bottom of the base 3, and a pressure sensor is provided between the bottom of the base 3 and the top of the electric telescopic rod 3.1, and the pressure sensor is connected to the controller of the electric telescopic rod 3.1. In this embodiment, there are multiple universal wheels 28 and multiple electric telescopic rods 3.1. For the convenience of control, multiple electric telescopic rods 3.1 can be uniformly controlled to rise and fall through the same controller to ensure their consistency.

[0044] When placing the steel pipe, if the position of the adjacent base 3 is inaccurate, the laser receiver 27 will not receive the signal. The operator can adjust the position of the base 3 in time according to this situation until the laser receiver 27 receives the signal normally, indicating that the position of the base 3 is accurate.

[0045] Through the cooperation of the laser emitter 26 and the laser receiver 27, the position of the base 3 can be detected quickly and accurately, which greatly improves the efficiency and accuracy of the steel pipe positioning, reduces the welding deviation caused by inaccurate positioning, and provides a basic guarantee for high-quality welding. In addition, in order not to affect the cooperation process of the laser emitter 26 and the laser receiver 27, the area of ​​the support seat 12 that may block the path of the laser emitter 26 to emit the laser is set to a hollow structure or a transparent material is selected.

[0046] refer to Figure 5 As shown, when it is necessary to move the limiting mechanism 1 and adjust its position to adapt to different working scenes or steel pipe welding at different positions, the operator can push the base 3 and use the flexible steering function of the universal wheel 28 to easily move the limiting mechanism 1 to the specified position.

[0047] The setting of the universal wheel 28 makes the movement of the limiting mechanism 1 more convenient and flexible, and can quickly respond to different work requirements, thereby improving the working efficiency and maneuverability of the entire welding device and reducing the labor intensity of the operator; at the same time, the universal wheel 28 itself has a brake system, which can be locked after adjustment, so that the base 3 remains fixed, which is convenient for subsequent grinding and welding processes.

[0048] In addition, during the dynamic centering of the steel pipe by the centering support assembly 29, the pressure sensor at the bottom of the base 3 detects the load-bearing condition of the base 3 in real time. If the load-bearing condition exceeds the preset value, the controller controls the electric telescopic rod 3.1 to retract. If the load-bearing condition is less than the preset value, the controller controls the electric telescopic rod 3.1 to extend, so that the load-bearing condition of the base 3 is always kept within the preset range. Finally, during the real-time calibration of the steel pipe axis by the centering support assembly 29, the base 3 can adjust the base height in real time according to the pressure change, so that the steel pipe can always be close to the surface of the base 3. At the same time, during the real-time calibration of the steel pipe axis by the centering support assembly 29, if the steel pipe is caused to undergo lateral displacement in the horizontal plane, the movement and adjustment process of the base 3 in the horizontal plane is directly realized by the movement of its universal wheel 28. Through the above process, the adjustment of the position of the base 3 always follows the real-time calibration of the steel pipe axis by the centering support assembly 29. refer to Figure 6 and 7 As shown, a number of groups of self-aligning support assemblies 29 are evenly arranged along the circumferential direction at the edge positions on both sides of the inner wall of the support ring 6, and each group of the self-aligning support assemblies 29 includes a mounting seat 291 fixed to the inner ring of the support ring 6, and the mounting seat 291 is connected to the support wheel frame 293 through a ball joint 292, and a support roller 294 is rotatably mounted on the support wheel frame 293; the rolling surface of the support roller 294 is an inwardly concave arc surface adapted to the outer wall of the steel pipe, and a reset spring 295 is connected between the support wheel frame 293 and the mounting seat 291, and the reset spring 295 always applies an elastic force to the support wheel frame 293 toward the axis of the steel pipe; an angle sensor is also provided at the ball joint 292 or the support wheel frame 293, which is used to calculate the offset of the axis of the steel pipe, and the angle sensor is connected to the controller of the rotating motor 24.

[0049] The present invention sets a self-aligning support assembly 29 with a ball joint and a reset spring on the inner wall of the support ring 6, and the arc rolling surface of the support roller is adapted to the outer wall of the steel pipe to form an elastic support structure that can be adaptively adjusted. In the prior art, the positioning of steel pipes mainly depends on the inclined surface of the limit frame and the laser centering system. For the ellipticity deviation of large-diameter steel pipes caused by dead weight or processing errors, there is a lack of dynamic self-aligning ability. The structure of the present invention allows the support wheel frame to rotate freely in three-dimensional space through the ball joint. With the elastic force of the reset spring, when the steel pipe enters along the axial direction, the support roller can be adaptively opened outward under the action of the reset spring, and automatically fit the outer wall of the steel pipe to achieve dynamic calibration of the steel pipe axis. At the same time, the limiting effect of multiple support rollers can also prevent the steel pipe from radial displacement during welding and grinding, solving the problem that the traditional rigid support cannot adapt to the deviation of the steel pipe shape, significantly improving the matching accuracy, and reducing welding defects caused by axis deviation. In addition, the swing angle of the support wheel frame 293 is monitored in real time by the angle sensor set on the support wheel frame 293 or the ball joint 292.

[0050] Embodiment 2: The present invention discloses a welding method for the above-mentioned large-diameter steel pipe butt welding device, comprising the following steps: Step S1: Place two sections of large-diameter steel pipes to be welded on the top of the base 3 of the two sets of limit mechanisms 1 respectively; in this process, the position accuracy of the base 3 is monitored in real time through the cooperation of the laser transmitter 26 and the laser receiver 27; if the laser receiver 27 cannot receive the laser signal, the system automatically issues an alarm to prompt the operator to adjust the position of the base 3 until the laser receiver 27 accurately receives the signal, thereby ensuring the accuracy of the initial placement of the two sections of steel pipes; Step S2: insert one end of the two sections of steel pipe to be welded into the inner ring of the support ring 6 by moving the base 3; in this process, the steel pipe is dynamically aligned by using the aligning support assembly 29 evenly arranged on the inner wall of the support ring 6; when the steel pipe is inserted, the support roller 294 is adaptively opened outward and fits the outer wall of the steel pipe under the action of the reset spring 295, and the ball joint 292 allows the support wheel frame 293 to rotate in three-dimensional space to adapt to the ovality deviation of the steel pipe caused by its own weight or processing error, and calibrate the axis of the steel pipe in real time until the axes of the two sections of the steel pipe are completely overlapped and the ends are in contact with each other; During the dynamic centering of the steel pipe by the centering support assembly 29, the pressure sensor at the bottom of the base 3 detects the load-bearing condition of the base 3 in real time. If the load-bearing condition exceeds the preset value, the controller controls the electric telescopic rod 3.1 to retract. If the load-bearing condition is less than the preset value, the controller controls the electric telescopic rod 3.1 to extend, so that the load-bearing condition of the base 3 is always kept within the preset range. Finally, during the real-time calibration of the steel pipe axis by the centering support assembly 29, the base 3 can adjust the base height in real time according to the pressure change, so that the steel pipe can always be close to the surface of the base 3. At the same time, during the real-time calibration of the steel pipe axis by the centering support assembly 29, if the steel pipe is caused to undergo lateral displacement in the horizontal plane, the movement and adjustment process of the base 3 in the horizontal plane is directly realized by the movement of its universal wheel 28. Through the above process, the adjustment of the position of the base 3 always follows the real-time calibration of the steel pipe axis by the centering support assembly 29. After the centering support assembly 29 completes the dynamic centering process of the steel pipe, the brake system of the universal wheel 28 is locked so that the base 3 remains stationary; Step S3: Start the telescopic rod 8. At this time, the distance sensor 25 on the movable plate 9 monitors the distance between the movable plate 9 and the steel pipe in real time. The controller of the telescopic rod 8 accurately adjusts the telescopic length of the telescopic rod 8 according to the signal fed back by the distance sensor 25, so that the distance between the movable plate 9 and the steel pipe is always kept within the set optimal distance range, ensuring that the welding gun 10 and the grinding assembly 11 can be in the best working position. Step S4: first start a set of grinding components 11 and the rotating motor 24. During the rotation of the sliding ring 7, the grinding component 11 grinds the surface of the steel pipe to be welded. Then start the welding gun 10 and another set of grinding components 11, so that the welding gun 10 and the set of grinding components 11 can continuously perform the annular welding process along the butt gap of the steel pipe.

[0051] The step S4 includes the following process: Step S4.1, first grinding: start the left assembly of the two symmetrically arranged grinding assemblies 11, and the sliding ring 7 rotates forward at the initial speed, so that the grinding assembly 11 moves in a circular motion along the outer wall of the steel pipe; The grinding assembly 11 adaptively fits the curved surface of the steel pipe through the hinged head 14 and the hinged seat 15, and the movable slide bar 19 and the spring 20 provide initial contact pressure to ensure that the rotating brush head 17 fits tightly with the surface of the steel pipe; If the distance sensor 25 detects that the fluctuation of the distance between the movable plate 9 and the steel pipe surface exceeds the preset safety threshold, the controller controls the telescopic rod 8 to automatically fine-tune, and at the same time, the movable slide bar 19 of the grinding assembly 11 slides in the fixed sleeve 18, and the spring 20 elastically compensates to maintain the pressure of the rotating brush head 17 stable; After each round of grinding, the visual inspection module performs a 360° scan of the grinding area and identifies residual oxide layers or oil stains through image grayscale analysis; if a substandard area is detected, that is, the grayscale value exceeds the standard range, the system marks the coordinates of the area, and the sliding ring 7 re-scans the area at a low speed in the subsequent rotation, while grinding the power boost part of the motor 16 until the inspection is qualified; S4.2, Steering compensation for abnormal working conditions: The deviation of the steel pipe axis is calculated by the swing angle of the ball joint 292 of the support wheel frame 293 in the self-aligning support assembly 29. When the deviation of the steel pipe axis exceeds the threshold, the brake system of the universal wheel 28 is unlocked, and then a "compensation steering pulse" of a certain angle is automatically inserted during the rotation of the sliding ring 7, that is, the original direction is restored after a short reverse rotation, ensuring that the grinding track is always evenly distributed along the circumference of the steel pipe, and then the brake system of the universal wheel 28 is re-locked; S4.3, Sliding ring forward and reverse strategy and path planning: During the base welding, the sliding ring 7 rotates forward at a low speed, and the grinding assembly 11 in front of the welding gun 10 rotates forward synchronously to remove residual impurities; During cap welding, the sliding ring 7 is reversed at high speed, and another set of grinding components 11 follows to grind the weld surface; When the visual inspection module identifies the weld undercut defect, the sliding ring 7 pauses in front of the defect position and performs slight forward and reverse reciprocating welding.

[0052] In step S4.2, the automatic insertion of a "compensation steering pulse" of a certain angle during the rotation of the slip ring 7 specifically includes the following process: Offset judgment and pulse triggering: The swing angle of the support wheel frame 293 is monitored in real time by the angle sensor set on the support wheel frame 293 or the ball joint 292. If the swing angle exceeds the threshold, it means that the self-aligning support assembly 29 has not calibrated the steel pipe axis, and the offset of the steel pipe axis exceeds the preset allowable range. At this time, the compensating steering pulse mechanism is immediately triggered; Pulse angle calculation: The system selects the angle of the steering pulse that needs to be compensated according to the degree of offset. The greater the offset, the greater the angle of the steering pulse. For example, when the offset is small, the compensation steering pulse angle is set to 3°; when the offset is large, the compensation steering pulse angle increases to 6°. At the same time, the system will also fine-tune the pulse angle based on the current rotation speed of the sliding ring and the working status of the grinding component to ensure the accuracy of the compensation.

[0053] Pulse execution process: During normal rotation, the sliding ring 7 immediately suspends the current rotation direction after receiving the compensation steering pulse command; then it performs a short reverse rotation according to the corresponding pulse angle; specifically, if the current sliding ring 7 is in a forward rotation state, it will reversely rotate by a certain pulse angle after receiving the pulse command. For example, if the current sliding ring is in a forward rotation state, it will reversely rotate by 3° or 6° after receiving the pulse command; during the reverse rotation process, the friction between the grinding component and the surface of the steel pipe will reversely push the steel pipe with the offset axis to shake, and then the axis of the steel pipe will be adaptively adjusted through the self-aligning support component 29; after the reverse rotation is completed, the sliding ring 7 quickly returns to the original rotation direction and continues the grinding operation; Multiple pulse compensation: If the self-aligning support assembly 29 detects that the steel pipe axis is still offset after one compensation steering pulse, the system will trigger the compensation steering pulse again; through multiple pulse compensation, the steel pipe axis is gradually adjusted to the allowable error range.

[0054] The above embodiments are only preferred technical solutions of the present invention and should not be regarded as limiting the present invention. The protection scope of the present invention shall be the technical solutions recorded in the claims, including equivalent replacement solutions of the technical features in the technical solutions recorded in the claims. That is, equivalent replacement improvements within this scope are also within the protection scope of the present invention.

Claims

1. A large-diameter steel pipe butt welding device, comprising a welding mechanism (2), wherein limiting mechanisms (1) are provided on both sides of the welding mechanism (2), and the characteristics are: The welding mechanism (2) comprises a support ring (6) arranged between two sets of limiting mechanisms (1); the bottom of the support ring (6) is fixed to the top of the support seat (12); the inner ring of the support ring (6) is provided with an annular rotation groove (13); the annular rotation groove (13) is slidably connected to a sliding ring (7); the sliding ring (7) is fixedly connected to one side of a movable plate (9) via a telescopic rod (8); and a welding gun (10) and a grinding assembly (11) are fixedly provided on the other side of the movable plate (9).

2. The large-diameter steel pipe butt welding device according to claim 1 is characterized in that: The grinding assembly (11) is provided in two groups and is symmetrically distributed on both sides of the welding gun (10); the grinding assembly (11) comprises an articulated seat (15), one end of the articulated seat (15) is hinged to the movable plate (9) via an articulated head (14), and the other end cooperates with the grinding motor (16); the output shaft of the grinding motor (16) is fixedly connected to the rotating brush head (17).

3. The large-diameter steel pipe butt welding device according to claim 2 is characterized in that: The grinding assembly (11) further comprises a fixed sleeve (18) and a movable slide rod (19); one end of the fixed sleeve (18) is fixedly connected to the other end of the hinge seat (15); the other end of the fixed sleeve (18) is slidably matched with one end of the movable slide rod (19); the other end of the movable slide rod (19) is fixedly connected to the grinding motor (16); a spring (20) is further provided between the inner side of the fixed sleeve (18) and the end of the movable slide rod (19).

4. The large-diameter steel pipe butt welding device according to claim 1 is characterized in that: The welding mechanism (2) further comprises a bracket (21) and a driving gear (22); a slot communicating with the annular rotating slot (13) is formed on the top of the support ring (6); the bracket (21) is fixedly arranged at the notch of the slot; the driving gear (22) is rotatably connected to the bracket (21); a tooth groove (23) meshing with the driving gear (22) is formed on the side of the sliding ring (7); the center of the driving gear (22) is fixedly connected to the output shaft of the rotating motor (24); and the rotating motor (24) is fixedly connected to the bracket (21).

5. The large-diameter steel pipe butt welding device according to claim 4 is characterized in that: A spacing sensor (25) and a visual detection module are also fixedly provided on the movable plate (9); the spacing sensor (25) is electrically connected to a controller of the telescopic rod (8), and the visual detection module is connected to a controller of the rotating motor (24).

6. The large-diameter steel pipe butt welding device according to claim 1 is characterized in that: The limiting mechanism (1) comprises a base (3), a symmetrically arranged limiting frame (4) is fixedly provided on the top of the base (3), and the limiting frame (4) is provided with an inclined surface (5); one of the bases (3) is provided with a laser transmitter (26), and the other base (3) is provided with a laser receiver (27); the limiting mechanism (1) also comprises universal wheels (28), a plurality of universal wheels (28) are provided and arranged in a matrix on the electric telescopic rod (3.1) at the bottom of the base (3), a pressure sensor is provided between the bottom of the base (3) and the top of the electric telescopic rod (3.1), and the pressure sensor is connected to a controller of the electric telescopic rod (3.1).

7. The large-diameter steel pipe butt welding device according to claim 6 is characterized in that: A plurality of groups of self-aligning support assemblies (29) are evenly arranged along the circumferential direction at the edge positions on both sides of the inner wall of the support ring (6), each group of the self-aligning support assemblies (29) comprising a mounting seat (291) fixed to the inner ring of the support ring (6), the mounting seat (291) being connected to a support wheel frame (293) via a ball joint (292), and a support roller (294) being rotatably mounted on the support wheel frame (293); the rolling surface of the support roller (294) being an inner concave arc surface adapted to the outer wall of the steel pipe, and a return spring (295) being connected between the support wheel frame (293) and the mounting seat (291), the return spring (295) always applying an elastic force toward the axis of the steel pipe to the support wheel frame (293); an angle sensor is also provided at the ball joint (292) or the support wheel frame (293) for calculating the offset of the axis of the steel pipe, and the angle sensor is connected to a controller of the rotating motor (24).

8. A welding method for the large-diameter steel pipe butt welding device according to any one of claims 1 to 7, characterized in that: The following steps are involved: Step S1: two sections of large-diameter steel pipes to be welded are respectively placed on the top of the base (3) of the two sets of limit mechanisms (1); during this process, the position accuracy of the base (3) is monitored in real time through the cooperation of the laser transmitter (26) and the laser receiver (27); if the laser receiver (27) cannot receive the laser signal, the system automatically issues an alarm to prompt the operator to adjust the position of the base (3) until the laser receiver (27) accurately receives the signal, thereby ensuring the accuracy of the initial placement of the two sections of steel pipes; Step S2: by moving the base (3), one end of the two steel pipes to be welded is inserted into the inner ring of the support ring (6); in this process, the steel pipe is dynamically aligned by using the aligning support assembly (29) evenly arranged on the inner wall of the support ring (6); when the steel pipe is inserted, the support roller (294) is adaptively opened outward and fits the outer wall of the steel pipe under the action of the return spring (295), and the ball joint (292) allows the support wheel frame (293) to rotate in three-dimensional space to adapt to the ovality deviation of the steel pipe caused by its own weight or processing error, and to calibrate the axis of the steel pipe in real time until the axes of the two steel pipes are completely overlapped and the ends are in contact with each other; During the dynamic centering of the steel pipe by the centering support assembly (29), the pressure sensor at the bottom of the base (3) detects the load-bearing condition of the base (3) in real time. If the load-bearing condition exceeds a preset value, the controller controls the electric telescopic rod (3.1) to retract. If the load-bearing condition is less than the preset value, the controller controls the electric telescopic rod (3.1) to extend, so that the load-bearing condition of the base (3) is always kept within a preset range. Finally, during the real-time centering of the steel pipe axis by the centering support assembly (29), the base (3) can adjust the base height in real time according to the pressure change, so that the steel pipe can always be in close contact with the surface of the base (3). Meanwhile, during the real-time centering of the steel pipe axis by the centering support assembly (29), if the steel pipe is caused to undergo lateral displacement in the horizontal plane, the movement and adjustment process of the base (3) in the horizontal plane is directly achieved by the movement of its universal wheel (28). Through the above process, the position adjustment of the base (3) always follows the real-time centering of the steel pipe axis by the centering support assembly (29). After the self-aligning support assembly (29) completes the dynamic self-aligning process of the steel pipe, the brake system of the universal wheel (28) is locked so that the base (3) remains stationary; Step S3: starting the telescopic rod (8), at which time the distance sensor (25) on the movable plate (9) monitors the distance between the movable plate (9) and the steel pipe in real time; the controller of the telescopic rod (8) accurately adjusts the telescopic length of the telescopic rod (8) according to the signal fed back by the distance sensor (25), so that the distance between the movable plate (9) and the steel pipe is always maintained within the set optimal distance range, ensuring that the welding gun (10) and the grinding assembly (11) can be in the optimal working position; Step S4: First, a set of grinding components (11) and a rotating motor (24) are started, and during the rotation of the sliding ring (7), the grinding component (11) grinds the surface of the portion of the steel pipe to be welded; then, the welding gun (10) and another set of grinding components (11) are started, so that the welding gun (10) and the set of grinding components (11) can continuously perform a circular welding process along the butt joint gap of the steel pipe.

9. The welding method according to claim 8, characterized in that: The step S4 includes the following process: Step S4.1, first grinding: start the left component of the two symmetrically arranged grinding components (11), and rotate the sliding ring (7) forward at the initial speed, so that the grinding component (11) moves in a circular motion along the outer wall of the steel pipe; The grinding assembly (11) adaptively fits the curved surface of the steel pipe through the hinged joint (14) and the hinged seat (15), and the movable slide rod (19) and the spring (20) provide initial contact pressure to ensure that the rotating brush head (17) fits tightly against the surface of the steel pipe; If the distance sensor (25) detects that the distance between the movable plate (9) and the steel pipe surface fluctuates beyond a preset safety threshold, the controller controls the telescopic rod (8) to automatically fine-tune, and at the same time the movable slide rod (19) of the grinding assembly (11) slides in the fixed sleeve (18), and the pressure of the rotating brush head (17) is maintained stable through elastic compensation by the spring (20); After each round of grinding, the visual inspection module performs a 360° scan of the grinding area and identifies residual oxide layers or oil stains through image grayscale analysis. If a substandard area is detected, that is, the grayscale value exceeds the standard range, the system marks the coordinates of the area, and the sliding ring (7) re-scans the area at a lower speed in the subsequent rotation, while grinding the power boost part of the motor (16) until the inspection is qualified. S4.2, Steering compensation under abnormal working conditions: The deviation of the steel pipe axis is calculated by the swing angle of the ball joint (292) of the support wheel frame (293) in the self-aligning support assembly (29). When the deviation of the steel pipe axis exceeds the threshold, the brake system of the universal wheel (28) is unlocked, and then a "compensation steering pulse" of a certain angle is automatically inserted during the rotation of the sliding ring (7), that is, the original direction is restored after a short reverse rotation, ensuring that the grinding track is always evenly distributed along the circumference of the steel pipe, and then the brake system of the universal wheel (28) is re-locked; S4.3, Sliding ring forward and reverse strategy and path planning: During the base welding, the sliding ring (7) rotates forward at a low speed, and the grinding assembly (11) in front of the welding gun (10) rotates forward synchronously to remove residual impurities; During the cap welding, the sliding ring (7) is reversed at high speed, and another set of grinding components (11) follows to grind the weld surface; When the visual inspection module identifies a weld undercut defect, the sliding ring (7) pauses in front of the defect position and performs reciprocating welding in a slightly forward and reverse manner.

10. The welding method according to claim 9, characterized in that: In step S4.2, a "compensation steering pulse" of a certain angle is automatically inserted during the rotation of the slip ring (7). The process includes: Offset judgment and pulse triggering: The swing angle of the support wheel frame (293) is monitored in real time by an angle sensor provided on the support wheel frame (293) or the ball joint (292). If the swing angle exceeds a threshold value, it indicates that the self-aligning support assembly (29) has not properly calibrated the steel pipe axis and the offset of the steel pipe axis exceeds a preset allowable range. At this time, the compensating steering pulse mechanism is immediately triggered; Pulse angle calculation: The system selects the angle of the steering pulse that needs to be compensated according to the degree of deviation. The greater the deviation, the greater the angle of the steering pulse required to be compensated. Pulse execution process: during normal rotation, the sliding ring (7) immediately pauses the current rotation direction upon receiving the compensation steering pulse command; then briefly reverses according to the corresponding pulse angle; specifically, if the sliding ring (7) is currently in a forward rotation state, upon receiving the pulse command, it will reversely rotate by a certain pulse angle; during the reverse rotation process, the friction between the grinding component and the surface of the steel pipe will reversely push the steel pipe with the axis offset to shake, and then the axis of the steel pipe will be adaptively adjusted through the self-aligning support component (29); after the reverse rotation is completed, the sliding ring (7) quickly returns to the original rotation direction and continues the grinding operation; Multiple pulse compensation: If after one compensation steering pulse, the self-aligning support assembly (29) detects that the steel pipe axis is still offset, the system will trigger the compensation steering pulse again; Through multiple pulse compensations, the axis of the steel pipe is gradually adjusted to within the allowable error range.

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