A laser welding device for large-diameter, thin-walled, high-frequency straight seam welded pipes.

Abstract

This invention discloses a laser welding device for large-diameter thin-walled high-frequency straight seam welded pipes, including a support base. A processing cylinder is fixedly installed at the top of the support base. Two welded pipe bodies are arranged inside the processing cylinder. A gas filtration mechanism is arranged inside the welded pipe bodies. The gas filtration mechanism includes an air pump fixedly installed at the top of the processing cylinder. The input end of the air pump is connected to the inside of the processing cylinder. A filter box is arranged at the output end of the air pump. The bottom end of the filter box is connected to the inside of the processing cylinder through a cold air duct. A cooling component is arranged on the cold air duct. This invention supplies air to the external pressurization component and the internal support component through the air pump to achieve synchronous linkage of internal and external clamping forces. At the same time, the magnetic plates embedded in the top plate and the pressure plate attract and position each other to ensure that the internal and external pressure points correspond one-to-one, preventing uneven local force from causing pipe end out-of-roundness. The spring buffer structure further weakens the clamping impact force, significantly reducing misalignment and collapse deformation when large-diameter thin-walled welded pipes are joined.

Description

Technical Field

[0001] This invention relates to the field of pipeline welding technology, and in particular to a laser welding device for large-diameter, thin-walled, high-frequency straight seam welded pipes. Background Technology

[0002] High-frequency straight seam welded pipes, with their advantages of high forming efficiency and low production cost, are widely used in oil and gas transportation, chemical fluid pipelines, and steel structure engineering. With the development of lightweight equipment, the demand for butt welding of large-diameter, thin-walled high-frequency straight seam welded pipes continues to increase. Laser welding, due to its concentrated energy, narrow heat-affected zone, and stable penetration depth, is gradually replacing traditional arc welding and becoming the mainstream process for circumferential butt welding of such pipes. In existing laser butt welding operations for large-diameter, thin-walled welded pipes, the thin-walled pipes themselves have weak structural rigidity, and the instantaneous high temperature of the laser causes severe thermal expansion and contraction in the weld area. When relying solely on external clamps, problems such as radial collapse, misalignment, and out-of-roundness deviations easily occur at the pipe ends. Simple external clamping cannot counteract the stress of inward contraction of the pipe wall. Currently, the few internal support fixtures available are mostly purely pneumatic telescopic clamping structures. The high welding temperature can cause pressure rise in the gas cavity, damage to the seals, and easy failure of the support force midway, thus seriously affecting the welding accuracy. Summary of the Invention

[0003] The purpose of this invention is to provide a laser welding device for large-diameter, thin-walled, high-frequency straight seam welded pipes, in order to solve the problems mentioned in the background art, such as radial collapse, misalignment, and out-of-roundness of the pipe opening when relying on external clamps, and the inability of simple external clamping to offset the stress of inward contraction of the pipe wall.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a laser welding device for large-diameter thin-walled high-frequency straight seam welded pipes, comprising a support base, a processing cylinder fixedly installed at the top of the support base, two spliced ​​welded pipe bodies arranged inside the processing cylinder, a gas filtering mechanism arranged inside the welded pipe body, the gas filtering mechanism including an air pump fixedly installed at the top of the processing cylinder, the input end of the air pump communicating with the interior of the processing cylinder, a filter box arranged at the output end of the air pump, the bottom end of the filter box communicating with the interior of the processing cylinder through a cold air duct, and a cooling component arranged on the cold air duct, a support assembly arranged inside the welded pipe body, the support assembly including an air inlet pipe arranged inside the welded pipe body, a gas collecting ring connected to the outer surface of the air inlet pipe, a plurality of second telescopic members connected to the outer surface of the gas collecting ring, and a top plate for supporting the connection area of ​​the two welded pipe bodies fixedly installed at the output end of the second telescopic members.

[0005] As a preferred embodiment of the present invention, the second telescopic member includes a slide cylinder that is connected to and installed on the surface of the gas collecting ring, and a slide rod is slidably installed inside the slide cylinder. The free end of the slide rod is fixedly connected to the top plate, and a spring for buffering the top plate is fixedly installed at one end of the slide rod located inside the slide cylinder.

[0006] As a preferred embodiment of the present invention, a one-way valve is provided at the air inlet end of the gas collecting ring near the slide cylinder, a pressure relief pipe is connected to the outer surface of the slide cylinder, a plurality of cylinders are fixedly installed on the outer surface of the slide cylinder, and a wedge-shaped slider for locking the top plate position by mechanical wedge clamping force is slidably installed inside the cylinder, and the free end of the pressure relief pipe is connected to one end of the cylinder.

[0007] As a preferred embodiment of the present invention, a pressurizing assembly is provided on the outer surface of the welded pipe body. The pressurizing assembly includes a fixed plate fixedly installed on both sides of the processing cylinder. An annular pipe is fixedly installed on the outer surface of the fixed plate. A plurality of first telescopic members are installed in communication with the surface of the annular pipe. A pressure plate is fixedly installed on the free end of the first telescopic member. The pressure plate, together with the top plate, is used to support the welded pipe body. The annular pipe is connected to the output end of the air pump.

[0008] As a preferred embodiment of the present invention, the output end of the air pump is connected to the annular pipe through an air outlet plate. An agitator is rotatably installed inside the air outlet plate to buffer the air intake of the first telescopic component and reduce the impact damage of the pressure plate on the surface of the welded pipe body. A rubber pad is fixedly installed on the surface of the pressure plate near the welded pipe body, and the cross-section of the pressure plate is arc-shaped.

[0009] As a preferred embodiment of the present invention, magnetic plates are embedded at the top of the top plate and inside the pressure plate. The top plate and the pressure plate are positioned by magnetic adsorption of the two magnetic plates. A friction pad is provided on the surface of the top plate near the welded pipe body to increase the stability of the top plate support.

[0010] As a preferred embodiment of the present invention, the air inlet pipe is connected to the output end of the air pump through the air inlet plate, and the interior of the air inlet pipe is filled with activated carbon flakes to adsorb the gas inside the pipe, remove water vapor, and prevent water vapor from affecting the welding stability inside the processing cylinder.

[0011] As a preferred embodiment of the present invention, an exhaust assembly is provided inside the welded pipe body. The exhaust assembly includes a support ring disposed in the welding area inside the two welded pipe bodies for sealing and supporting the welding area. A support air cylinder is fixedly installed on the outer surface of the air inlet pipe. The support air cylinder and the support ring are fixedly connected by a fixing frame.

[0012] As a preferred embodiment of the present invention, the support ring has an exhaust groove on its surface near the welding area, and an intake inner pipe is provided inside the outer air inlet pipe. The intake inner pipe is connected to the inside of the filter box through the outlet pipe, and the intake inner pipe is connected to the inside of the exhaust groove, for discharging the gas generated in the welding area inside the welded pipe body.

[0013] As a preferred embodiment of the present invention, a welding mechanism is provided inside the processing cylinder. The welding mechanism includes a welding equipment body fixedly installed on the outer surface of the processing cylinder, a rotating ring fixedly installed inside the processing cylinder, and a welding plate equipped with a laser welding head rotatably installed inside the rotating ring. This plate is used to perform laser scanning welding along the longitudinal straight seam or butt joint circumferential seam of the welded pipe body under the condition that the gas filtration mechanism performs internal and external pneumatic clamping and magnetic alignment on the welded pipe body. Multiple laser welding tubes are fixedly installed on the surface of the welding plate, a first gear is fixedly installed on one side of the welding plate, a motor is fixedly installed inside the processing cylinder, and a second gear is fixedly installed at the output end of the motor, with the first gear meshing with the second gear.

[0014] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention supplies air to the external pressurizing components and internal support components via an air pump, achieving synchronous linkage of internal and external clamping forces. An agitator impeller inside the air outlet plate buffers the incoming airflow, preventing the pressure plate from rapidly extending and impacting the pipe wall, thus preventing indentations on the surface of the thin-walled welded pipe. Magnetic plates embedded in the top plate and pressure plate mutually attract and position each other, ensuring a one-to-one correspondence between the internal and external pressure points, preventing uneven local force that could cause pipe end de-rounding. Combined with a spring buffer structure, this further weakens the clamping impact force, significantly reducing misalignment and collapse deformation during the butt welding of large-diameter thin-walled welded pipes.

[0015] 2. This invention uses an internal support assembly to push the second telescopic component against the inner wall of the weld seam using air pressure. After the support is in place, the air pressure inside the slide cylinder is introduced into the cylinder through the pressure relief pipe to push the wedge-shaped slider to wedge and lock the top plate. After locking, the internal air pressure can be released, and the support force is no longer maintained by air pressure, avoiding support failure caused by high temperature pressure rise and rubber seal damage. With the help of a one-way valve, gas backflow can be prevented. Under high temperature conditions, the rigid support of the inner wall of the weld seam can still be maintained, effectively resisting welding shrinkage stress.

[0016] 3. This invention utilizes activated carbon flakes inside the intake outer pipe to adsorb moisture and impurities in the gas. Simultaneously, the exhaust grooves on the intake inner pipe and support ring directionally extract fumes, metal vapors, and residual air from the weld root, preventing the accumulation of harmful gases within the pipe cavity that could cause weld oxidation and porosity. Furthermore, the cold air duct, equipped with a cooling component, delivers dry, cold air into the pipe, providing uniform temperature control over the welding area. The controlled airflow prevents disturbance to the laser molten pool, achieving precise cooling while reducing cold cracking in the weld.

[0017] 4. This invention uses a motor to drive the welding plate to rotate around a ring, with multiple sets of laser welding tubes arranged around the welded pipe, reducing the need for rotating heavy large-diameter pipes. The welding beam moves at a uniform speed around the circumferential seam, ensuring even heat input distribution and avoiding localized overheating caused by prolonged continuous heating at a single point. This effectively reduces thermal deformation of thin-walled pipes, and the weld bead width is uniform throughout, improving the consistency of the forming process.

[0018] 5. After the support component is depressurized and unlocked, the telescopic component can retract smoothly without weld slag blocking the tooling removal. At the same time, the internal support ring not only seals and blocks air, but also assists in positioning the pipe opening. One device can simultaneously complete multiple functions such as pipe opening positioning, rigid anti-deformation support, atmosphere purification, directional exhaust and surrounding laser welding, improving the stability of batch continuous welding production of large-diameter thin-walled welded pipes. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a side view of the structure of the present invention; Figure 3 This is a schematic diagram of the internal structure of the processing cylinder of the present invention; Figure 4 This is a schematic diagram of the internal structure of the welded pipe body of the present invention; Figure 5 This is a schematic diagram of the exhaust assembly of the present invention; Figure 6 This is a schematic diagram of the pressurization component of the present invention; Figure 7 This is a schematic diagram of the structure of the support component of the present invention; Figure 8 This is a schematic diagram of the internal structure of the second telescopic component of the present invention; Figure 9 This is a schematic diagram of the support ring structure of the present invention; Figure 10 This is a schematic diagram of the welding mechanism of the present invention.

[0020] In the diagram: 1. Processing cylinder; 2. Welded pipe body; 3. Support base; 4. Air filtration mechanism; 41. Air pump; 42. Filter box; 43. Refrigeration component; 44. Exhaust assembly; 441. Intake inner pipe; 442. Support ring; 443. Exhaust groove; 444. Fixing frame; 445. Support air cylinder; 45. Cold air duct; 46. Air inlet plate; 47. Air outlet plate; 48. Pressurization assembly; 481. Annular pipe; 482. Fixing plate; 483. First telescopic component; 4 84. Pressure plate; 49. Support assembly; 491. Top plate; 492. Second telescopic component; 493. Gas collecting ring; 494. Inlet pipe; 495. Magnetic plate; 496. Wedge slider; 497. Cylinder; 498. Pressure relief pipe; 499. Spring; 4910. One-way valve; 5. Welding mechanism; 51. Rotating ring; 52. Welding plate; 53. Welding equipment body; 54. Laser welding tube; 55. First gear; 56. Second gear; 57. Motor. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Please see Figure 1-10 This invention provides a laser welding device for large-diameter thin-walled high-frequency straight seam welded pipes, including a support base 3. A processing cylinder 1 is fixedly installed at the top of the support base 3. Two welded pipe bodies 2 are arranged inside the processing cylinder 1. A gas filtering mechanism 4 is arranged inside the welded pipe body 2. The gas filtering mechanism 4 includes an air pump 41 fixedly installed at the top of the processing cylinder 1. The input end of the air pump 41 is connected to the inside of the processing cylinder 1. A filter box 42 is arranged at the output end of the air pump 41. The bottom end of the filter box 42 is connected to the inside of the processing cylinder 1 through a cold air duct 45. A cooling component 43 is arranged on the cold air duct 45. A support assembly 49 is arranged inside the welded pipe body 2. The support assembly 49 includes an air inlet pipe 494 arranged inside the welded pipe body 2. A gas collecting ring 493 is connected to the outer surface of the air inlet pipe 494. A plurality of second telescopic members 492 are connected to the outer surface of the gas collecting ring 493. A top plate 491 for supporting the connection area of ​​the two welded pipe bodies 2 is fixedly installed at the output end of the second telescopic members 492.

[0023] The process involves activating the air pump 41 to continuously extract waste gas generated during welding inside the processing cylinder 1. The extracted gas is first sent to the filter box 42 for unified filtration and purification to remove impurities and particulate matter. The purified gas is then transported through the cold air duct 45, where it is cooled by the refrigeration component 43. The cooled, clean gas is then returned to the processing cylinder 1, continuously optimizing the welding environment and reducing the base temperature of the welding area. Simultaneously, the pressurized gas output from the air pump 41 is synchronously sent to the inlet pipe 494 inside the welded pipe. The gas is then diverted to the gas collecting ring 493, which evenly distributes the high-pressure gas to each set of second telescopic components 492. The air pressure drives all the second telescopic components 492 to extend outwards synchronously, causing the top plate 491 at the top to press against the inner wall of the welding area between the two welded pipe bodies 2. This provides uniform radial support and restraint at the weld joint from inside the pipe, solving the problems of weak rigidity, easy collapse, and poor welding accuracy of large-diameter thin-walled welded pipes, and significantly improving the welding stability of the welded pipes.

[0024] In some embodiments, the second telescopic member 492 includes a slide cylinder that is connected to the surface of the gas collecting ring 493, and a slide rod is slidably installed inside the slide cylinder. The free end of the slide rod is fixedly connected to the top plate 491, and a spring 499 for cushioning the top plate 491 is fixedly installed at one end of the slide rod located inside the slide cylinder.

[0025] The high-pressure gas output from the gas collecting ring 493 enters the interior of the slide cylinder, pushing the slide rod inside the slide cylinder to slide outward, thereby causing the top plate 491 to adhere to and support the inner wall of the welded pipe. When welding is completed, the gas pump 41 stops supplying gas, and the gas filtering mechanism 4 is depressurized, the gas pressure inside the cylinder 497 disappears. At this time, due to the axial reverse elastic force released by the spring 499, the top plate and slide rod are pushed back in the opposite direction, thereby forcibly overcoming the residual friction of the wedge slider 496 and driving the wedge slider 496 to return to its original position laterally, achieving automatic unlocking and reset. During the laser welding process, the weld area undergoes slight thermal deformation due to high temperature, and the pipe wall will exert a slight reverse compressive force on the top plate 491. At this time, the spring 499 can adaptively extend and retract according to the magnitude of the compressive force, and adjust the support tightness of the top plate 491 in real time, always maintaining the flexible fit and support between the top plate 491 and the pipe wall. This ensures that the weld area is effectively supported throughout the process, and can adaptively offset the stress fluctuations caused by welding vibration and thermal deformation, achieving flexible adaptive support throughout the process, resulting in higher support stability.

[0026] In some embodiments, a one-way valve 4910 is provided at the air inlet end of the gas collecting ring 493 near the slide cylinder, a pressure relief pipe 498 is connected to the outer surface of the slide cylinder, a plurality of cylinders 497 are fixedly installed on the outer surface of the slide cylinder, a wedge-shaped slider 496 for locking the position of the top plate 491 by mechanical wedge clamping force is slidably installed inside the cylinder 497, and the free end of the pressure relief pipe 498 is connected to one end of the cylinder 497.

[0027] During the air pressure tightening process of the telescopic top plate 491, the one-way valve 4910 at the air inlet end of the air collecting ring 493 remains in a state of conducting air intake and cutting off backflow, ensuring that the air pressure inside the slide cylinder remains stable and preventing gas backflow and pressure loss that could cause the top plate 491 to loosen or the support to fail. When the air pump 41 is first started supplying air, the slide rod extends outward under the push of air pressure. At this time, the piston end of the slide rod has not yet passed the air inlet of the pressure relief pipe 498, and no air pressure flows through the pressure relief pipe 498. The wedge-shaped slider 496 remains in its initial state. When the slide rod is fully extended and presses against the inner wall of the welded pipe body 2, the piston end of the slide rod passes through the opening, and the air pressure inside the slide cylinder can be introduced into the cylinder 497 through the pressure relief pipe 498. The air pressure pushes the wedge-shaped slider 496 inside the cylinder 497 to slide laterally. Using the self-locking principle of the wedge-shaped inclined surface, the limiting slide rod is pressed from the outside, completely mechanically locking the slide rod to the extended position of the top plate 491. After locking, the slide bar is no longer affected by internal air pressure fluctuations or high-temperature pressure rise and air leakage during welding. It is no longer dependent on air pressure and the support state of the top plate 491 is changed from flexible air pressure support to rigid mechanical self-locking support. This achieves a dual support mode of air pressure pre-lift and mechanical self-locking. Rigid support can be maintained without pressure holding throughout the welding process, which greatly improves the structural reliability under high-temperature laser welding conditions and reduces weld collapse and misalignment problems caused by support failure.

[0028] In some embodiments, a pressurizing assembly 48 is provided on the outer surface of the welded pipe body 2. The pressurizing assembly 48 includes a fixing plate 482 fixedly installed on both sides of the processing cylinder 1. An annular pipe 481 is fixedly installed on the outer surface of the fixing plate 482. A plurality of first telescopic members 483 are connected to the surface of the annular pipe 481. A pressure plate 484 is fixedly installed at the free end of the first telescopic member 483. The pressure plate 484 cooperates with the top plate 491 to support the welded pipe body 2. The annular pipe 481 is connected to the output end of the air pump 41.

[0029] The air pump 41 supplies air to the annular pipe 481 on the fixed plates 482 on both sides of the processing cylinder 1. The annular pipe 481 evenly distributes the high-pressure gas to multiple sets of first telescopic components 483 arranged circumferentially. Each set of first telescopic components 483 extends outward synchronously and uniformly, causing the arc-shaped pressure plate 484 at the end to fit and press against the outer docking area of ​​the two welded pipe bodies 2. The outer pressure plate 484 forms a uniform annular clamping pressure, which corresponds precisely to the inner and outer support structure of the top plate 491 inside the pipe and cooperates in both directions. It forms a two-way clamping and positioning constraint on the welded pipe docking position after splicing, locking the coaxiality of the welded pipe docking from the outside. With the help of the internal support, it offsets the radial deformation of the welding. The internal and external forces counterbalance each other, effectively offsetting the radial shrinkage stress generated by the laser welding of thin-walled welded pipes, greatly improving the coaxiality and roundness accuracy of the welded pipe docking, effectively solving the problems of easy loss of roundness, misalignment, and offset in the welding of large-diameter thin-walled welded pipes, and significantly improving the welding assembly accuracy.

[0030] In some embodiments, the output end of the air pump 41 is connected to the annular pipe 481 through the air outlet plate 47. An agitator is rotatably installed inside the air outlet plate 47 to buffer the air intake of the first telescopic member 483 and reduce the impact damage of the pressure plate 484 on the surface of the welded pipe body 2. A rubber pad is fixedly installed on the surface of the pressure plate 484 near the surface of the welded pipe body 2, and the cross section of the pressure plate 484 is arc-shaped.

[0031] When the air pump 41 supplies gas to the annular pipe 481 to clamp the first telescopic component 483, the high-pressure airflow first flows through the interior of the air outlet plate 47. The high-speed airflow impacts and drives the agitator impeller inside the air outlet plate 47 to rotate continuously. During the rotation of the impeller, the instantaneous high-pressure airflow is diverted, decelerated, and stabilized, significantly reducing the impact pressure of the airflow and allowing the air pressure entering the first telescopic component 483 to increase steadily. The first telescopic component 483 extends smoothly, causing the pressure plate 484 to adhere to the outer wall of the welded pipe at a low speed, reducing the impact indentation and collision damage to the thin-walled pipe wall caused by the instantaneous high-pressure clamping. At the same time, the pressure plate 484 adopts an arc structure that matches the outer wall of the welded pipe, and a rubber pad is set on the contact surface, which can closely fit the curved surface of the pipe wall, increase the clamping contact area, disperse the clamping stress, achieve flexible and stable clamping, and effectively protect the appearance and structure of the welded pipe base material.

[0032] In some embodiments, magnetic plates 495 are embedded in the top of the top plate 491 and the interior of the pressure plate 484. The top plate 491 and the pressure plate 484 are positioned by magnetic adsorption of the two magnetic plates 495. A friction pad is provided on the surface of the top plate 491 near the welded pipe body 2 to increase the stability of the support of the top plate 491.

[0033] During the synchronous bonding process of the inner and outer clamping supports, the built-in infrared sensor provides feedback on the alignment signal, avoiding the interference of the magnetic shielding effect of the thick-walled steel pipe on the positioning accuracy. This ensures that the clamping force points of multiple pressure plates 484 and the top plate 491 are collinear in the circumferential direction, preventing additional bending moments caused by misalignment. At this time, the magnetic plates 495 embedded at corresponding positions of the inner top plate 491 and the outer pressure plate 484 magnetically attract and align with each other. The magnetic adsorption effect automatically corrects the deviation of the inner and outer pressure points, ensuring that the clamping position of each outer pressure plate 484 corresponds precisely to the support position of the inner top plate 491, achieving symmetrical force distribution in the circumferential direction. Simultaneously, the friction pad on the inner wall of the top plate 491 is tightly attached to the inner wall of the welded pipe, significantly increasing the static friction between the top plate 491 and the pipe wall. Under the action of welding vibration and thermal stress, this effectively prevents the top plate 491 from slipping, shifting, or loosening, locking the support points and reducing pipe deformation and weld offset caused by uneven local force distribution.

[0034] In some embodiments, the air inlet pipe 494 is connected to the output end of the air pump 41 through the air inlet plate 46. The interior of the air inlet pipe 494 is filled with activated carbon flakes to adsorb the gas inside the pipe, remove water vapor, and prevent water vapor from affecting the welding stability inside the processing cylinder 1.

[0035] The gas output from the air pump 41 is sent into the air intake pipe 494 via the air intake plate 46. As the gas flows through the air intake pipe 494, it comes into full contact with the activated carbon particles filled inside. Utilizing the porous adsorption properties of the activated carbon particles, it continuously adsorbs harmful media such as water vapor, fine dust, and impurity particles contained in the airflow, performing deep drying and purification of the circulating gas. The purified and dried gas is then diverted and transported to the gas collecting ring 493, the telescopic structure, and the welding area inside the processing cylinder 1. This process prevents water-containing and impurity-containing gases from entering the welding station, reducing the decomposition of water vapor at high laser temperatures to produce oxidation media and the accumulation of impurities that affect weld formation. It also avoids defects such as oxidation, porosity, and cracks during high-temperature welding, and stabilizes the welding protective atmosphere.

[0036] In some embodiments, an exhaust assembly 44 is provided inside the welded pipe body 2. The exhaust assembly 44 includes a support ring 442 disposed in the welding area inside the two welded pipe bodies 2 for sealing and supporting the welding area. A support air cylinder 445 is fixedly installed on the outer surface of the air inlet pipe 494. The support air cylinder 445 and the support ring 442 are fixedly connected by a fixing bracket 444.

[0037] During the assembly of the internal support component 49 of the welded pipe body 2, the air inlet pipe 494, through the support air cylinder 445 and the fixing frame 444, fixes the support ring 442, ensuring that the support ring 442 is precisely positioned at the internal butt weld position of the two welded pipe bodies 2. Before welding, the support ring 442 fits and seals the gap inside the weld, forming an annular seal to isolate the inside of the welding area, preventing external welding slag, dust, and impurities from entering the weld joint gap and avoiding impurities from being trapped inside the weld and causing welding defects. At the same time, the support ring 442 itself forms an annular support base, providing auxiliary support to the weak area inside the weld of the thin-walled welded pipe body 2, counteracting the root collapse tendency caused by high-temperature softening during welding, and providing a stable installation benchmark for subsequent directional venting at the weld root, ensuring the stability of the weld formation.

[0038] In some embodiments, the support ring 442 has an exhaust groove 443 on its surface near the welding area, and an intake inner pipe 441 is provided inside the intake outer pipe 494. The intake inner pipe 441 is connected to the inside of the filter box 42 through the exhaust pipe, and the intake inner pipe 441 is connected to the inside of the exhaust groove 443, for discharging the gas generated in the welding area inside the welded pipe body 2.

[0039] During laser welding, the high-temperature molten pool of the weld continuously generates harmful gases such as metal vapor, welding fumes, and high-temperature exhaust gases, which accumulate in the weld root area inside the weld pipe body 2. At this time, the air pump 41 continuously generates negative pressure suction, which is connected to the exhaust groove 443 on the surface of the support ring 442 through the suction inner pipe 441 to directionally and specifically extract the harmful gases accumulated at the weld root. After the exhaust gas is collected through the exhaust groove 443, it is uniformly transported to the filter box 42 through the suction inner pipe 441 and the exhaust pipe for filtration and purification treatment, realizing the centralized discharge and purification of harmful gases, effectively reducing oxidation, porosity, and slag inclusion defects at the weld root, and improving the forming stability of the weld root.

[0040] In some embodiments, a welding mechanism 5 is provided inside the processing cylinder 1. The welding mechanism 5 includes a welding equipment body 53 fixedly installed on the outer surface of the processing cylinder 1. A rotating ring 51 is fixedly installed inside the processing cylinder 1. A welding plate 52 equipped with a laser welding head is rotatably installed inside the rotating ring 51. The welding plate 52 is used to perform laser scanning welding along the longitudinal straight seam or butt joint circumferential seam of the welded pipe body 2 under the condition that the gas filtration mechanism 4 performs internal and external pneumatic clamping and magnetic alignment on the welded pipe body 2. A plurality of laser welding tubes 54 are fixedly installed on the surface of the welding plate 52. A first gear 55 is fixedly installed on one side of the welding plate 52. A motor 57 is fixedly installed inside the processing cylinder 1. A second gear 56 is fixedly installed at the output end of the motor 57, and the first gear 55 meshes with the second gear 56.

[0041] In this process, motor 57 starts, driving the second gear 56 to rotate, which in turn drives the first gear 55 to rotate, thereby causing the welding plate 52 to rotate at a uniform speed along the rotating ring 51 inside the processing cylinder 1. Multiple sets of laser welding tubes 54 mounted on the welding plate 52 synchronously follow this rotation, forming a ring-shaped laser heat source. This allows for all-around uniform welding of the fixed circumferential butt weld seam without rotating the large-diameter weld pipe body 2. The synchronous circular welding by multiple laser heads ensures uniform heat input and stable welding speed, avoiding problems such as pipe rotation vibration, misalignment, and localized overheating throughout the process. It completes continuous laser welding of the entire circumferential seam at a uniform speed, effectively reducing localized thermal deformation of the thin-walled weld pipe and significantly improving the uniformity of the circumferential weld seam formation and welding efficiency.

[0042] Working Principle: During operation, the two large-diameter, thin-walled, high-frequency straight-seam welded pipe bodies 2 are first placed inside the processing cylinder 1 to complete the initial splicing and alignment. The support base 3 provides stable support for the entire processing cylinder 1. The air pump 41 is started to continuously extract the waste gas generated during welding inside the processing cylinder 1. The extracted gas is first sent to the filter box 42 for unified filtration and purification to remove impurities and particulate matter. The purified gas is then transported through the cold air duct 45. During this process, the gas is cooled by the refrigeration component 43. The cooled, clean cold air is then returned to the processing cylinder 1, continuously optimizing the welding working environment and reducing the base temperature of the welding area. At the same time, the air pressure medium output by the air pump 41 is synchronously sent into the air inlet pipe 494 inside the welded pipe. The air is then diverted to the air collecting ring 493 through the air inlet pipe 494. The air collecting ring 493 evenly distributes the high-pressure gas to each group of second telescopic components 492. The air pressure drives all the second telescopic components 492 to extend outward synchronously, causing the top plate 491 at the top to press against the inner wall of the welding area of ​​the two welded pipe bodies 2. This forms a uniform radial support limit for the weld joint position from inside the pipe, solving the problems of weak rigidity, easy collapse, and poor welding accuracy of large-diameter thin-walled welded pipes, and significantly improving the welding stability of the welded pipes.

[0043] The above are merely specific embodiments of the present invention, but the technical features of the present invention are not limited thereto. Any simple changes, equivalent substitutions, or modifications made based on the present invention to solve essentially the same technical problems and achieve essentially the same technical effects are all covered within the protection scope of the present invention.

Claims

1. A laser welding device for large-diameter thin-walled high-frequency straight seam welded pipes, comprising a support base (3), characterized in that: A processing cylinder (1) is fixedly installed at the top of the support base (3). Two spliced ​​welded pipe bodies (2) are arranged inside the processing cylinder (1). A gas filtration mechanism (4) is arranged inside each welded pipe body (2). The gas filtration mechanism (4) includes an air pump (41) fixedly installed at the top of the processing cylinder (1). The input end of the air pump (41) is connected to the interior of the processing cylinder (1). A filter box (42) is provided at the output end of the air pump (41). The bottom end of the filter box (42) is connected to the interior of the processing cylinder (1) through a cold air duct (45), and the cold air... A cooling component (43) is provided on the conduit (45), and a support assembly (49) is provided inside the welded pipe body (2). The support assembly (49) includes an air inlet pipe (494) provided inside the welded pipe body (2). An air collecting ring (493) is connected to the outer surface of the air inlet pipe (494), and a plurality of second telescopic members (492) are connected to the outer surface of the air collecting ring (493). A top plate (491) for supporting the connection area of ​​the two welded pipe bodies (2) is fixedly installed at the output end of the second telescopic member (492).

2. The laser welding device for large-diameter thin-walled high-frequency straight seam welded pipes according to claim 1, characterized in that: The second telescopic member (492) includes a slide cylinder that is connected to the surface of the air collecting ring (493), and a slide rod is slidably installed inside the slide cylinder. The free end of the slide rod is fixedly connected to the top plate (491), and a spring (499) for buffering the top plate (491) is fixedly installed at one end of the slide rod inside the slide cylinder.

3. The laser welding device for large-diameter thin-walled high-frequency straight seam welded pipes according to claim 1, characterized in that: The gas collecting ring (493) is provided with a one-way valve (4910) near the air inlet end of the slide. The outer surface of the slide is connected to a pressure relief pipe (498). Multiple cylinders (497) are fixedly installed on the outer surface of the slide. A wedge-shaped slider (496) for locking the position of the top plate (491) by mechanical wedge clamping force is slidably installed inside the cylinder (497). The free end of the pressure relief pipe (498) is connected to one end of the cylinder (497).

4. The laser welding device for large-diameter thin-walled high-frequency straight seam welded pipes according to claim 1, characterized in that: The outer surface of the welded pipe body (2) is provided with a pressurizing component (48). The pressurizing component (48) includes a fixing plate (482) fixedly installed on both sides of the processing cylinder (1). An annular pipe (481) is fixedly installed on the outer surface of the fixing plate (482). A plurality of first telescopic members (483) are connected to the surface of the annular pipe (481). A pressure plate (484) is fixedly installed at the free end of the first telescopic member (483). The pressure plate (484) cooperates with the top plate (491) to support the welded pipe body (2). The annular pipe (481) is connected to the output end of the air pump (41).

5. The laser welding device for large-diameter thin-walled high-frequency straight seam welded pipes according to claim 1, characterized in that: The output end of the air pump (41) is connected to the annular pipe (481) through the air outlet plate (47). The air outlet plate (47) is rotatably equipped with an agitator impeller, which is used to buffer the air intake of the first telescopic component (483) and reduce the impact damage of the pressure plate (484) on the surface of the welded pipe body (2). The pressure plate (484) is fixedly installed with a rubber pad near the surface of the welded pipe body (2), and the cross section of the pressure plate (484) is arc-shaped.

6. The laser welding device for large-diameter thin-walled high-frequency straight seam welded pipes according to claim 1, characterized in that: The top of the top plate (491) and the interior of the pressure plate (484) are both equipped with magnetic plates (495). The top plate (491) and the pressure plate (484) are positioned by magnetic adsorption of the two magnetic plates (495). The surface of the top plate (491) near the welded pipe body (2) is provided with friction pads to increase the stability of the support of the top plate (491).

7. A laser welding apparatus for large-diameter thin-walled high-frequency straight seam welded pipes according to claim 5, characterized in that: The air inlet pipe (494) is connected to the output end of the air pump (41) through the air inlet plate (46). The interior of the air inlet pipe (494) is filled with activated carbon flakes, which are used to adsorb the gas inside the pipe, remove water vapor, and prevent water vapor from affecting the welding stability inside the processing cylinder (1).

8. The laser welding device for large-diameter thin-walled high-frequency straight seam welded pipes according to claim 1, characterized in that: The inside of the welded pipe body (2) is provided with an exhaust assembly (44). The exhaust assembly (44) includes a support ring (442) disposed in the welding area inside the two welded pipe bodies (2) for sealing and supporting the welding area. The outer surface of the air inlet pipe (494) is fixedly installed with a support air cylinder (445). The support air cylinder (445) and the support ring (442) are fixedly connected by a fixing bracket (444).

9. A laser welding apparatus for large-diameter thin-walled high-frequency straight seam welded pipes according to claim 8, characterized in that: The support ring (442) has an exhaust groove (443) on its surface near the welding area. The air inlet pipe (494) has an air intake pipe (441) inside. The air intake pipe (441) is connected to the inside of the filter box (42) through the air outlet pipe, and the air intake pipe (441) is connected to the inside of the exhaust groove (443) to exhaust the gas generated in the welding area inside the welded pipe body (2).

10. A laser welding apparatus for large-diameter, thin-walled, high-frequency straight seam welded pipes according to claim 1, characterized in that: The processing cylinder (1) is equipped with a welding mechanism (5). The welding mechanism (5) includes a welding equipment body (53) fixedly installed on the outer surface of the processing cylinder (1). A rotating ring (51) is fixedly installed inside the processing cylinder (1). A welding plate (52) with a laser welding head is rotatably installed inside the rotating ring (51). It is used to perform laser scanning welding along the longitudinal straight seam or butt joint circumferential seam of the welded pipe body (2) under the condition of internal and external pneumatic clamping and magnetic alignment by the gas filtering mechanism (4). Multiple laser welding tubes (54) are fixedly installed on the surface of the welding plate (52). A first gear (55) is fixedly installed on one side of the welding plate (52). A motor (57) is fixedly installed inside the processing cylinder (1). A second gear (56) is fixedly installed at the output end of the motor (57), and the first gear (55) meshes with the second gear (56).

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