Laser welding device for welding steel pipes

Abstract

The application relates to the field of welding equipment, in particular to a laser welding device for welding a steel pipe. The laser welding device comprises a main frame, a laser welding head, two clamping mechanisms, two circumferential sealing mechanisms, an atmosphere forming mechanism and an air curtain forming mechanism. The steel pipe is fixed by the clamping mechanisms, and the air curtain forming mechanism and the circumferential sealing mechanism are used to perform circumferential sealing and axial sealing on the welding position. The air curtain forming mechanism is arranged outside the atmosphere forming mechanism in the circumferential direction, so that a stable welding environment is ensured, external air is prevented from entering the welding area, the inert gas concentration is maintained, the welding quality and precision are improved, and at the same time, smoke leakage during the welding process is avoided, and the diffusion of welding smoke is effectively limited.

Description

Technical Field

[0001] This application relates to the field of welding equipment, and more specifically, to a laser welding apparatus for welding steel pipes. Background Technology

[0002] Steel pipes, as a key material in basic industries and engineering construction, are widely used in petroleum, chemical, and construction industries. Their welding quality directly affects structural safety and service life. Laser welding, with its advantages of high precision, high efficiency, and stable welding quality, is gradually becoming an important development direction for steel pipe welding. With the development of industrial intelligence, laser welding equipment has demonstrated significant advantages in automation, flexibility, and improved production efficiency, providing reliable technical support for steel pipe manufacturing and promoting the development of welding processes towards high-end, intelligent, and green manufacturing. Therefore, it has significant application value and broad development prospects in the field of steel pipe manufacturing.

[0003] In the prior art, laser welding apparatus for welding steel pipes typically includes a welding platform and a transfer platform connected together. The welding platform is equipped with a drive assembly, which is operatively connected to a laser welding head located above the transfer platform. The transfer platform is equipped with a transfer device for moving the steel pipe below the laser welding head. The overlapping area between the upstream of the transfer direction and the laser welding head forms a welding zone. Downstream of the transfer direction, there are several sets of support units distributed along the axial direction of the steel pipe. Each support unit includes three support modules evenly distributed at 120° along the circumference of the steel pipe. Each support module includes a shell structure, a coil assembly, a magnetorheological fluid actuator, and a contact head assembly arranged sequentially from the outside to the inside along a radial direction of the steel pipe.

[0004] In actual use, the high temperature of laser welding causes the metal surface to melt rapidly, generating fumes and particulate matter during the evaporation process. These fumes mainly consist of metal vapor, oxides, and other substances. Especially when welding highly reactive metals or materials containing harmful components, the composition of the fumes may pose potential hazards to operators and the environment. Inhalation of metal fumes and oxides may lead to respiratory diseases, and long-term exposure to certain harmful metals may even increase the risk of occupational diseases or cancer. At the same time, fumes deposited on the optical components or welding area of ​​the laser equipment can reduce laser output power, affect the stability of the molten pool, cause weld defects, and increase equipment maintenance costs. Summary of the Invention

[0005] The purpose of this invention is to provide a laser welding device for welding steel pipes, which ensures welding quality while preventing the leakage of harmful fumes.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a laser welding apparatus for welding steel pipes, comprising:

[0007] Mainframe rack;

[0008] The laser welding head is fixed on the inner top wall of the main frame and is used for welding steel pipes;

[0009] Two clamping mechanisms are arranged opposite each other on the main frame along the axial direction of the steel pipe to clamp the steel pipe. Each clamping mechanism includes a first limiting plate arranged on the main frame, a first toothed disc arranged in the first limiting plate, a plurality of clamping components arranged circumferentially on the first toothed disc to clamp the steel pipe, and a rotating component for driving the first toothed disc to rotate.

[0010] Two circumferential sealing mechanisms are arranged opposite to each other on the main frame along the axial direction of the steel pipe and located between the two clamping mechanisms. Each circumferential sealing mechanism includes a second limiting plate arranged on the main frame, a second toothed disc arranged in the second limiting plate, a plurality of sealing plates arranged on the second toothed disc, and a transmission assembly formed between the second toothed disc and the motor. The plurality of sealing plates are driven by the second toothed disc to converge toward the steel pipe to fit against the circumference of the steel pipe.

[0011] An atmosphere forming mechanism is located between two second limiting plates. The atmosphere forming mechanism includes a first air outlet component mounted on one of the second limiting plates and a first air inlet component mounted on the other second limiting plate. The first air outlet component outputs nitrogen gas, and the first air inlet component recovers nitrogen gas.

[0012] An air curtain forming mechanism is located between two second limiting plates and is positioned circumferentially outside the air curtain forming mechanism. The air curtain forming mechanism includes a second air outlet assembly mounted on the side wall of one of the second limiting plates and a second air inlet assembly mounted on the side wall of the other second limiting plate. An annular air curtain is formed between the second air outlet assembly and the second air inlet assembly.

[0013] Furthermore, the first gas outlet assembly includes a nitrogen cylinder, a first connecting pipe, a second gas pump, a first delivery pipe, a second annular pipe, and a gas guide ring. A slot is provided on the outer wall of the first limiting plate. The nitrogen cylinder is detachably connected to the inner side of the slot. The gas outlet end of the nitrogen cylinder is fixedly connected to the first connecting pipe. The top end of the first connecting pipe is fixedly connected to the second gas pump. The output end of the second gas pump is fixedly connected to the first delivery pipe. The bottom end of the first delivery pipe is fixedly connected to the second annular pipe. The gas guide ring is fixedly connected to the inner side of the second annular pipe. Evenly distributed baffles are fixedly connected to the inner side of the gas guide ring. Multiple guide plates are fixedly connected to the inner side of the gas guide ring.

[0014] Furthermore, the first air intake assembly includes a third air pump, an air outlet pipe, a filter device, and a second delivery pipe; the third air pump is fixedly connected to the inner side of the top of the second limiting plate, the air outlet end of the third air pump is fixedly connected to the air outlet pipe, the air outlet pipe is externally connected to the filter device, the air intake end of the third air pump is fixedly connected to the second delivery pipe, and the bottom end of the second delivery pipe is fixedly connected to a second annular pipe, an air guide ring, a partition plate, and a flow guide plate, which are the same as those in the first air intake assembly.

[0015] Furthermore, the second air outlet assembly includes a first guide pipe, a split pipe, a first air pump, a connecting tube, and an air delivery pipe; the first guide pipe is fixedly connected to the outer wall of the air guide ring near the second air pump, and an air outlet is fixedly connected to the side of the first guide pipe away from the second annular pipe; the split pipe is fixedly connected to the outer wall of the first guide pipe; the first air pump is fixedly connected to the bottom end of the split pipe; the connecting tube is fixedly connected to the air inlet end of the first air pump; the air delivery pipe is fixedly connected to the outer wall of the connecting tube; and the air delivery pipe is fixedly connected to the outer wall of the second limiting plate on the adjacent side.

[0016] Furthermore, the second air intake assembly includes a second guide pipe, a manifold, a filter element, and a second connecting sleeve; the second guide pipe is fixedly connected to the outer wall of the air guide ring near the third air pump, and an air inlet is fixedly connected to the outer wall of the second guide pipe away from the third air pump; the manifold is fixedly connected to the outer wall of the second guide pipe; the filter element is detachably connected to the bottom end of the manifold; the second connecting sleeve is fixedly connected to the outer wall of the filter element; the second connecting sleeve is fixedly connected to a second limiting plate on the adjacent side; the connecting tube is slidably connected to the filter element; and the air supply pipe is slidably connected to the second connecting sleeve.

[0017] Furthermore, the rotating assembly includes a motor fixed on the first limiting plate, a first driving gear disposed on the output shaft of the motor, and a first transmission gear rotatably mounted on the first limiting plate, wherein the first transmission gear meshes with the first driving gear and the first gear plate respectively.

[0018] Furthermore, the clamping assembly includes a second fixing frame fixedly connected to the end face of the first gear plate, a second hydraulic rod mounted on the second fixing frame, and a clamping plate mounted on the output end of the second hydraulic rod.

[0019] Furthermore, the circumferential sealing mechanism also includes a limiting plate located between the first toothed disc and the second toothed disc; the sealing plate is located between the limiting plate and the second toothed disc, the second toothed disc is provided with a plurality of first guide grooves, the limiting plate is provided with a plurality of second guide grooves, and the sealing plate is provided with a first transmission rod and a second transmission rod respectively cooperating with the first guide groove and the second guide groove; the first guide groove and the second guide groove extend along the convergence direction of the sealing plate.

[0020] Furthermore, the transmission assembly includes a second drive gear, a second transmission gear, a fixed sleeve, a transmission gear disc, a third hydraulic rod, a damping ring, a hexagonal rod, and a connecting gear disc. The fixed sleeve is fixedly connected to the bottom of the outer wall of the second limiting plate. The second transmission gear is rotatably mounted on the second limiting plate and meshes with the second gear disc and the second drive gear, respectively. The transmission gear disc is fixedly connected to the outer wall of the first drive gear on the side away from the motor. The third hydraulic rod is fixedly connected to the inner side of the fixed sleeve. The output end of the third hydraulic rod is rotatably connected to the damping ring. The side of the damping ring away from the fixed sleeve is rotatably connected to the hexagonal rod. The second drive gear is sleeved on the hexagonal rod. The end of the hexagonal rod is fixedly connected to the connecting gear disc, and the connecting gear disc is engaged with the transmission gear disc.

[0021] Furthermore, the two clamping mechanisms and the two circumferential sealing mechanisms are arranged in a one-to-one manner to form two modules, and at least one of the modules is provided with a sliding assembly between it and the main frame. The main frame is provided with a first hydraulic rod that drives the module to move axially along the steel pipe.

[0022] The beneficial effects of the present invention are as follows: The laser welding device for welding steel pipes of this application fixes the steel pipe by a clamping mechanism and uses an air curtain forming mechanism and a circumferential sealing structure to seal the welding position circumferentially and axially. By setting the air curtain forming mechanism circumferentially outside the atmosphere forming mechanism, a stable welding environment is ensured, external air is prevented from entering the welding area, the inert gas concentration is maintained, and the welding quality and precision are improved. At the same time, it also avoids the leakage of fumes during the welding process and effectively limits the diffusion of welding fumes.

[0023] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0024] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0025] Figure 2 This is a partial three-dimensional structural diagram of the connecting rod in this invention;

[0026] Figure 3 This is a partial three-dimensional structural diagram of the support frame in this invention;

[0027] Figure 4 This is a schematic diagram of the three-dimensional structure of the fixed sleeve in one direction in this invention;

[0028] Figure 5This is a schematic diagram of the three-dimensional structure of the fixed sleeve in another direction in this invention;

[0029] Figure 6 This is a schematic cross-sectional view of the first limiting plate in this invention;

[0030] Figure 7 This is a schematic cross-sectional view of the second limiting plate in this invention;

[0031] Figure 8 This is a schematic cross-sectional view of the support frame in this invention;

[0032] Figure 9 yes Figure 8 Enlarged view of point A in the middle;

[0033] Figure 10 This is a structural breakdown diagram of the sealing plate in this invention;

[0034] Figure 11 This is a structural breakdown diagram of the second annular tube in this invention;

[0035] Figure 12 This is a schematic cross-sectional view of the first guide tube in this invention;

[0036] Figure 13 This is a schematic cross-sectional view of the air guide ring in this invention.

[0037] In the diagram: 1. Main frame; 11. First fixed frame; 12. First hydraulic rod; 13. Connecting rod; 14. Sliding rod; 15. Sliding sleeve; 2. Support frame; 21. First limiting plate; 22. Second limiting plate; 3. Motor; 31. First drive gear; 32. First transmission gear; 33. First gear plate; 34. Second fixed frame; 35. Second hydraulic rod; 36. Clamping plate; 4. Fixed sleeve; 41. Third hydraulic rod; 42. Damping ring; 43. Hexagonal rod; 44. Connecting gear plate; 45. Transmission gear plate; 5. Second drive gear; 51. Second transmission gear; 52. Second gear plate; 53. First guide groove; 54. First transmission rod; 55. Sealing plate 56. Second transmission rod; 57. Limiting plate; 58. Second guide groove; 6. First guide pipe; 61. Air outlet; 62. Diverter pipe; 63. First air pump; 64. Connecting tube; 65. Gas delivery pipe; 66. Filter element; 67. Second connecting sleeve; 68. Manifold; 69. Second guide pipe; 610. Air inlet; 7. Slot; 71. Nitrogen cylinder; 72. First connecting pipe; 73. Second air pump; 74. First delivery pipe; 8. Second annular pipe; 81. Air guide ring; 82. Partition plate; 83. Guide plate; 9. Third air pump; 91. Air outlet pipe; 92. Second delivery pipe; 20. Laser welding head; 30. Clamping mechanism; 40. Circumferential sealing mechanism. Detailed Implementation

[0038] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. 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.

[0039] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0040] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0041] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0042] Please see Figures 1-13 The laser welding apparatus for welding steel pipes shown in one embodiment of this application includes: a main frame 1, a laser welding head 20, two clamping mechanisms 30, two circumferential sealing mechanisms 40, an atmosphere forming mechanism, and an air curtain forming mechanism. The laser welding head 20 is fixed on the inner top wall of the main frame 1 and is used for welding steel pipes. The laser welding head 20 adopts existing technology and is externally connected to laser production equipment.

[0043] Two clamping mechanisms 30 are arranged opposite each other on the main frame 1 along the axial direction of the steel pipe to clamp the steel pipe. Each clamping mechanism 30 includes a first limiting plate 21 arranged on the main frame 1, a first gear 33 arranged in the first limiting plate 21, a plurality of clamping components arranged circumferentially on the first gear 33 to clamp the steel pipe, and a rotating component for driving the first gear 33 to rotate. The rotating component may include a motor 3 fixed on the first limiting plate 21, a first drive gear 31 arranged on the output shaft of the motor 3, and a first transmission gear 32 rotatably mounted on the first limiting plate 21. The first transmission gear 32 meshes with the first drive gear 31 and the first gear 33 respectively. Specifically, the first limiting plate 21 has a hollow portion for accommodating the first gear 33, and the first gear 33 has an accommodating space for pushing the steel pipe in. The first gear 33 is generally annular in structure, and the accommodating space is the hollow portion of the annular structure. The clamping assembly is arranged circumferentially on the end face of the first gear plate 33. Therefore, in this embodiment, the steel pipe is placed laterally on the clamping mechanism 30, or more specifically, laterally on the main frame 1. In an alternative embodiment, the clamping assembly includes a second fixing frame 34 fixedly connected to the end face of the first gear plate 33, a second hydraulic rod 35 mounted on the second fixing frame 34, and clamping plates 36 mounted on the output end of the second hydraulic rod 35. After the steel pipe is pushed into the accommodating space and reaches the appropriate position, the second hydraulic rod 35 is activated to push several clamping plates 36 towards the central axis of the accommodating space, thereby clamping the steel pipe. During the welding process, the motor 3 drives the first gear plate 33 to rotate, causing the clamped steel pipe to rotate, thus enabling the laser welding head 20 to weld the steel pipe.

[0044] Two circumferential sealing mechanisms 40 are arranged opposite each other on the main frame 1 along the axial direction of the steel pipe and located between the two clamping mechanisms 30. Each circumferential sealing mechanism 40 includes a second limiting plate 22 disposed on the main frame 1, a second toothed disc 52 disposed within the second limiting plate 22, a plurality of sealing plates 55 disposed on the second toothed disc 52, and a transmission assembly formed between the second toothed disc 52 and the motor 3. The plurality of sealing plates 55 are driven by the second toothed disc 52 to converge toward the steel pipe to fit against the circumference of the steel pipe. Specifically, the second limiting plate 22 has a hollow portion for accommodating the second toothed disc 52, and the second toothed disc 52 has an accommodating space for pushing the steel pipe in. The second toothed disc 52 is also generally annular in structure, and its accommodating space is the hollow portion of the annular structure. The axes of the accommodating space of the first toothed disc 33 and the accommodating space of the second toothed disc 52 overlap, and both are the same size.

[0045] It should be noted that when the sealing plates 55 are attached to the circumferential direction of the steel pipe, there is a gap seal between the sealing plates 55 and the steel pipe. When the steel pipe rotates under the drive of the first gear plate 33, the steel pipe can move within the sealing plates 55. In this embodiment, the sealing plates 55 are aggregated and attached to each other in the circumferential direction to form a ring structure.

[0046] In one embodiment, the circumferential sealing mechanism further includes a limiting disk 57 located between the first toothed disk 33 and the second toothed disk 52. A sealing plate 55 is located between the limiting disk 57 and the second toothed disk 52. The second toothed disk 52 has several first guide grooves 53, and the limiting disk 57 has several second guide grooves 58. The sealing plate 55 is provided with a first transmission rod 54 and a second transmission rod 56 that respectively cooperate with the first guide grooves 53 and the second guide grooves 58. The first guide grooves 53 and the second guide grooves 58 extend along the convergence direction of the sealing plate 55. When the second toothed disk 52 rotates, it drives the first guide grooves 53 to rotate synchronously, thereby driving the first transmission rods 54 to rotate. The sealing plate 55 rotates through the cooperation of the first transmission rods 54 and the second transmission rods 56, causing the sealing plate 55 to rotate. Thus, by having several sealing plates 55 rotate simultaneously, they come into contact with the outer wall of the steel pipe, achieving a circumferential seal on the steel pipe.

[0047] In one embodiment, the transmission assembly includes a second drive gear 5, a second transmission gear 51, a fixed sleeve 4, a transmission gear 45, a third hydraulic rod 41, a damping ring 42, a hexagonal rod 43, and a connecting gear 44. The fixed sleeve 4 is fixedly connected to the bottom of the outer wall of the second limiting plate 22. The second transmission gear 51 is rotatably mounted on the second limiting plate 22 and meshes with the second gear 52 and the second drive gear 5, respectively. The transmission gear 45 is fixedly connected to the outer wall of the first drive gear 31 on the side away from the motor 3. The third hydraulic rod 41 is fixedly connected to the inner side of the fixed sleeve 4. The output end of the third hydraulic rod 41 is rotatably connected to the damping ring 42. The side of the damping ring 42 away from the fixed sleeve 4 is rotatably connected to the hexagonal rod 43. The second drive gear 5 is sleeved on the hexagonal rod 43. The end of the hexagonal rod 43 is fixedly connected to the connecting gear 44. The connecting gear 44 is engaged with the transmission gear 45. The third hydraulic rod 41, with the fixed sleeve 4 as the stress point, drives the damping ring 42, the hexagonal rod 43, and the connecting gear 44 to move. After the connecting gear 44 engages with the transmission gear 45, the power from the motor 3 driving the first drive gear 31 to rotate is transmitted to the second drive gear 5 via the connecting gear 44 and the hexagonal rod 43. The second drive gear 5 then drives the top second gear 52 to rotate synchronously via the second transmission gear 51, sealing the gap in the outer wall of the steel pipe. When the connecting gear 44 and the transmission gear 45 disengage, the third hydraulic rod 41 provides a stress point for the hexagonal rod 43, and the damping between the damping ring 42 and the hexagonal rod 43 restricts the rotation of the second drive gear 5, thus limiting the angle of the top second gear 52.

[0048] Two clamping mechanisms 30 and two circumferential sealing mechanisms 40 are arranged in a one-to-one configuration to form two modules. At least one module is connected to the main frame 1 via a sliding assembly. The main frame 1 is equipped with a first hydraulic rod 12 that drives the module to move axially along the steel pipe. In this embodiment, the first hydraulic rod 12 drives one module to move axially along the steel pipe. Specifically, a first fixing frame 11 is provided on the inner bottom of the main frame 1, and the first hydraulic rod 12 is fixed to the side wall of the first fixing frame 11. The sliding assembly includes sliding rods 14 fixed to both sides inside the main frame 1 and a sliding sleeve 15 slidably connected to the sliding rods 14. A support frame 2 is fixed above the sliding sleeve 15, and a connecting rod 13 is fixed to the bottom wall of the middle section of the support frame 2. The connecting rod 13 is fixedly connected to the output end of the first hydraulic rod 12. The module is fixed on the support frame 2. The first hydraulic rod 12 drives a set of sliding sleeves 15 to move on the slide rod 14 with the first fixed frame 11 as the stress point. The sliding sleeves 15 drive the support frame 2 to move synchronously, thereby realizing the axial movement of the module along the steel pipe.

[0049] The atmosphere forming mechanism is located between two second limiting plates 22. The atmosphere forming mechanism includes a first exhaust component mounted on one of the second limiting plates 22 and a first intake component mounted on the other second limiting plate 22. The first exhaust component outputs nitrogen gas, and the first intake component recovers nitrogen gas to form a nitrogen protective atmosphere in the welding area.

[0050] Specifically, the first gas outlet assembly includes a nitrogen cylinder 71, a first connecting pipe 72, a second gas pump 73, a first delivery pipe 74, a second annular pipe 8, and a gas guide ring 81. A slot 7 is provided on the outer wall of the first limiting plate 21. The nitrogen cylinder 71 is detachably connected to the inner side of the slot 7. The gas outlet end of the nitrogen cylinder 71 is fixedly connected to the first connecting pipe 72. The top end of the first connecting pipe 72 is fixedly connected to the second gas pump 73. The output end of the second gas pump 73 is fixedly connected to the first delivery pipe 74. The bottom end of the first delivery pipe 74 is fixedly connected to the second annular pipe 8. The gas guide ring 81 is fixedly connected to the inner side of the second annular pipe 8. Evenly distributed partitions 82 are fixedly connected to the inner side of the gas guide ring 81. Multiple guide plates 83 are fixedly connected to the inner side of the gas guide ring 81. The first air intake assembly includes a third air pump 9, an air outlet pipe 91, a filter device, and a second delivery pipe 92. The third air pump 9 is fixedly connected to the inner side of the top of the second limiting plate 22. The air outlet end of the third air pump 9 is fixedly connected to the air outlet pipe 91. The filter device is connected to the outside of the air outlet pipe 91. The air inlet end of the third air pump 9 is fixedly connected to the second delivery pipe 92. The bottom end of the second delivery pipe 92 is fixedly connected to a second annular pipe 8, an air guide ring 81, a partition plate 82, and a guide plate 83, which are the same as those in the first air intake assembly.

[0051] The air curtain forming mechanism is located between the two second limiting plates 22 and is located outside the atmosphere forming mechanism in the circumferential direction. The air curtain forming mechanism includes a second air outlet assembly installed on the side wall of one of the second limiting plates 22 and a second air inlet assembly installed on the side wall of the other second limiting plate 22. The second air outlet assembly sprays out gas (external air) and the second air inlet assembly recovers the gas, so that an annular air curtain is formed between the second air outlet assembly and the second air inlet assembly.

[0052] In one embodiment, the second air outlet assembly includes a first guide pipe 6, a branch pipe 62, a first air pump 63, a connecting tube 64, and an air delivery pipe 65. The first guide pipe 6 is fixedly connected to the outer wall of the air guide ring 81 near the second air pump 73. An air outlet 61 is fixedly connected to the side of the first guide pipe 6 away from the second annular pipe 8. The branch pipe 62 is fixedly connected to the outer wall of the first guide pipe 6. The first air pump 63 is fixedly connected to the bottom end of the branch pipe 62. The connecting tube 64 is fixedly connected to the air inlet end of the first air pump 63. The air delivery pipe 65 is fixedly connected to the outer wall of the connecting tube 64. The air delivery pipe 65 is fixedly connected to the outer wall of the second limiting plate 22 on the adjacent side.

[0053] The second air intake assembly includes a second guide pipe 69, a manifold 68, a filter element 66, and a second connecting sleeve 67. The second guide pipe 69 is fixedly connected to the outer wall of the air guide ring 81 on the side near the third air pump 9. An air inlet 610 is fixedly connected to the outer wall of the second guide pipe 69 on the side away from the third air pump 9. The manifold 68 is fixedly connected to the outer wall of the second guide pipe 69. The filter element 66 is detachably connected to the bottom end of the manifold 68. The second connecting sleeve 67 is fixedly connected to the outer wall of the filter element 66. The second connecting sleeve 67 is fixedly connected to the second limiting plate 22 on the adjacent side. The connecting tube 64 is slidably connected to the filter element 66. The air supply pipe 65 is slidably connected to the second connecting sleeve 67.

[0054] In practical applications, the first air pump 63 draws in external air using the connecting tube 64, filter element 66, manifold 68, second guide tube 69, and air inlet 610, and delivers it into the first guide tube 6 through the split tube 62. The air is then output in a ring shape through the first guide tube 6 to form an air curtain. The airflow on the air curtain is collected through the air inlet 610 to form a cycle. During the process, the filter element 66 filters the dust in the small amount of flue gas entering the airflow. When the first hydraulic rod 12 moves the top support frame 2, the air delivery tube 65 and the second connecting sleeve 67, the connecting tube 64, and the filter element 66 are connected by insertion when the two sides of the support frame 2 move closer together.

[0055] The second air pump 73 uses the first connecting pipe 72 to extract nitrogen from the nitrogen cylinder 71 and delivers it into the second annular pipe 8 through the first delivery pipe 74. The nitrogen is then distributed through the second annular pipe 8 to ensure even distribution within the gas guide ring 81, thereby allowing the nitrogen to be transported into the gas curtain through the guide plate 83. The third air pump 9 uses the second annular pipe 8 at the bottom and the gas guide ring 81 to extract nitrogen from inside the gas curtain, allowing the nitrogen to flow from one end of the gas curtain to the other. This circulation of nitrogen within the gas curtain helps to carry away the fumes generated during welding, preventing fumes from accumulating inside the gas curtain.

[0056] The laser welding device used for welding steel pipes operates as follows:

[0057] First, place the steel pipes on both sides onto the clamping plate 36. Then, use the second hydraulic rod 35 to move the clamping plate 36 inward simultaneously with the second fixing frame 34 as the stress point, thereby clamping and fixing the steel pipes.

[0058] Then, the third hydraulic rod 41 drives the damping ring 42, hexagonal rod 43 and connecting gear 44 to move towards the transmission gear 45 with the fixed sleeve 4 as the stress point, so that the connecting gear 44 and the transmission gear 45 engage with each other. Then, the motor 3 drives the first drive gear 31 to rotate. When the first drive gear 31 rotates, it drives the first transmission gear 32 at the top and the transmission gear 45 on the outside to rotate synchronously. When the first transmission gear 32 rotates, it drives the first gear 33 at the top to rotate synchronously, thereby driving the clamping assembly and the inner steel pipe to rotate through the first gear 33.

[0059] Simultaneously, the transmission gear 45 drives the second drive gear 5 to rotate synchronously via the connecting gear 44 and the hexagonal rod 43. The second drive gear 5 then drives the second gear 52 at the top to rotate via the second transmission gear 51. In turn, the second gear 52 drives the first transmission rod 54 to rotate synchronously via the first guide groove 53. The limiting plate 57 remains stationary. The second transmission rod 56 limits the sealing plate 55, causing the sealing plate 55 to move around both the first transmission rod 54 and the second transmission rod 56. This allows the sealing plate 55 to fit against the outer wall of the steel pipe, thereby sealing the gap in the outer wall of the steel pipe.

[0060] Then, the fixed sleeve 4 drives the damping ring 42, the hexagonal rod 43 and the connecting gear plate 44 to move away from the transmission gear plate 45, disconnecting the connection between the connecting gear plate 44 and the transmission gear plate 45, and limiting the hexagonal rod 43 through the damping ring 42 to prevent it from rotating.

[0061] Then, the first hydraulic rod 12 drives the connecting rod 13, the support frame 2 at the top of the connecting rod 13, and the steel pipe to move towards the first fixed frame 11, so that the ends of the steel pipes on both sides are connected. At the same time, the filter element 66 and the second connecting sleeve 67 are moved towards the connecting tube 64 and the air supply pipe 65, so that the second connecting sleeve 67 is inserted into the air supply pipe 65, the filter element 66 and the connecting tube 64 to form a connection.

[0062] After the connection is completed, the first hydraulic rod 12 stops running, while the first air pump 63 uses the connecting tube 64, filter element 66, manifold 68, second guide tube 69 and air inlet 610 to draw in external air, and uses the split tube 62 to deliver it into the first guide tube 6. The air is then output in a ring shape through the first guide tube 6 to form an air curtain. The airflow on the air curtain is collected through the air inlet 610 to form a cycle.

[0063] During the process, the nitrogen gas in the nitrogen cylinder 71 is extracted by the second air pump 73 through the first connecting pipe 72 and transported into the second annular pipe 8 through the first delivery pipe 74. The nitrogen gas is then distributed through the second annular pipe 8 and evenly enters the gas guide ring 81. The nitrogen gas is then transported into the gas curtain through the guide plate 83 to replace the air inside the gas curtain and fill the gas curtain with nitrogen, thereby maintaining the stability of the welding environment.

[0064] Meanwhile, the third air pump 9 on the other side extracts nitrogen from inside the air curtain through the second annular pipe 8 and the air guide ring 81 at the bottom, so that the nitrogen flows from one end of the air curtain to the other end, allowing the nitrogen to circulate inside the air curtain. This can carry away the fumes generated during the welding process, and the nitrogen along with the fumes is transported into the external filtration equipment through the air outlet pipe 91 to separate the nitrogen and fumes.

[0065] After the nitrogen gas curtain is filled, the laser welding head 20 starts operating to weld the connection between the two ends of the steel pipe.

[0066] To ensure the air curtain provides a sealing effect without significantly impacting welding quality, the flow rate of the air curtain is set to 8–15 m / s in this embodiment. It should be noted that because the airflow direction of the air curtain is parallel to the steel pipe axis and orthogonal to the direction of the molten pool opening (radial), the airflow primarily produces tangential shearing rather than direct impact on the molten pool, allowing the molten pool to remain stable within this flow rate range. Simultaneously, the viscous boundary layer on the steel pipe surface significantly attenuates the airflow velocity close to the wall, resulting in the actual airflow velocity experienced by the molten pool being much lower than the mainstream velocity of the air curtain, further ensuring the stability of the welding process.

[0067] This laser welding device for welding steel pipes fixes the steel pipe with a clamping mechanism and uses an air curtain forming mechanism and a circumferential sealing structure to seal the welding position circumferentially and axially. By setting the air curtain forming mechanism circumferentially outside the atmosphere forming mechanism, a stable welding environment is ensured, preventing external air from entering the welding area, maintaining the concentration of inert gas, improving welding quality and precision, and at the same time, preventing the leakage of fumes during the welding process and effectively limiting the diffusion of welding fumes.

[0068] Specifically, the second exhaust component and the second intake component work together to create an annular air curtain to seal the welding position, preventing the leakage of fumes during the welding process, effectively limiting the diffusion of welding fumes, reducing interference to operators and laser beam paths, and the annular air curtain can also stabilize the molten pool, reduce spatter, improve welding uniformity, and help extend the life of optical components, support high-quality automated welding, and improve overall welding efficiency and safety.

[0069] Inert nitrogen is supplied into the air curtain through the first exhaust component, thereby replacing the air in the welding area. The nitrogen is then extracted from the other side through the first intake component, creating an airflow within the air curtain. This prevents oxygen from entering the welding area and causing oxidation defects, while maintaining a uniform and stable inert atmosphere. This reduces defects such as porosity and cracks during the welding process, improving weld density and mechanical properties. At the same time, the stabilizing effect of the airflow improves the uniformity of the welding environment and welding accuracy, reduces the impact of welding spatter and temperature fluctuations, increases the efficiency of automated welding, extends the service life of laser optical components and equipment, reduces the leakage of harmful fumes, and improves operational safety. This comprehensively improves the quality, accuracy, and production efficiency of laser welding of steel pipes. The process also carries away the welding fumes, and external filtration equipment filters the dust in the nitrogen to prevent leakage.

[0070] The rotating and clamping components can automatically clamp and rotate the steel pipe, which improves the automation level of the equipment, enhances the welding accuracy and consistency, ensures uniform and complete welds, and significantly improves production efficiency. It is especially suitable for large-volume steel pipe welding operations. Automatic clamping and rotation stabilize the steel pipe, prevents the pipe from shaking or shifting during the welding process, ensures that the laser beam acts precisely on the weld position, and reduces defects.

[0071] Through the transmission component, the sealing component can be connected to the rotating component during operation, driving the sealing component to operate simultaneously and seal the steel pipe from all sides. This ensures the airtightness of the air curtain, stabilizing the welding environment, preventing external air from entering the welding area, maintaining the inert gas concentration, and improving welding quality and precision. Simultaneously, the sealing component effectively prevents protective gas leakage, reduces gas waste, improves efficiency, and lowers costs. Automated synchronous operation reduces manual intervention, improving production efficiency and consistency. The seal also prevents harmful fumes from leaking out, improving operational safety and comprehensively enhancing the performance, reliability, and working environment of the laser welding steel pipe device.

[0072] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0073] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A laser welding apparatus for welding steel pipes, characterized in that, include: Mainframe (1); The laser welding head (20) is fixed on the inner top wall of the main frame (1) and is used to weld steel pipes; Two clamping mechanisms (30) are arranged opposite each other on the main frame (1) along the axial direction of the steel pipe to clamp the steel pipe. Each clamping mechanism (30) includes a first limiting plate (21) arranged on the main frame (1), a first toothed disc (33) arranged in the first limiting plate (21), a plurality of clamping components arranged circumferentially on the first toothed disc (33) to clamp the steel pipe, and a rotating component that drives the first toothed disc (33) to rotate. Two circumferential sealing mechanisms (40) are arranged opposite to each other on the main frame (1) along the axial direction of the steel pipe and located between the two clamping mechanisms (30). Each circumferential sealing mechanism (40) includes a second limiting plate (22) arranged on the main frame (1), a second toothed disc (52) arranged in the second limiting plate (22), a plurality of sealing plates (55) arranged on the second toothed disc (52), and a transmission assembly formed between the second toothed disc (52) and the motor (3). The plurality of sealing plates (55) are driven by the second toothed disc (52) to converge toward the direction of the steel pipe to fit against the circumference of the steel pipe. An atmosphere forming mechanism is located between two second limiting plates (22). The atmosphere forming mechanism includes a first exhaust component mounted on one of the second limiting plates (22) and a first intake component mounted on the other second limiting plate (22). The first exhaust component outputs nitrogen gas, and the first intake component recovers nitrogen gas. An air curtain forming mechanism is located between two second limiting plates (22) and is located outside the atmosphere forming mechanism in the circumferential direction. The air curtain forming mechanism includes a second air outlet assembly installed on the side wall of one of the second limiting plates (22) and a second air inlet assembly installed on the side wall of the other second limiting plate (22). An annular air curtain is formed between the second air outlet assembly and the second air inlet assembly. The rotating assembly includes a motor (3) fixed on a first limiting plate (21), a first driving gear (31) disposed on the output shaft of the motor, and a first transmission gear (32) rotatably mounted on the first limiting plate. The first transmission gear (32) meshes with the first driving gear (31) and the first gear disc (33) respectively. The circumferential sealing mechanism also includes a limiting plate (57) located between the first gear disc (33) and the second gear disc (52). The sealing plate is located between the limiting plate (57) and the second gear disc (52). The second gear disc has a plurality of first guide grooves (53), and the limiting plate (57) has a plurality of second guide grooves (58). The sealing plate is provided with a first transmission rod (54) and a second transmission rod (56) respectively cooperating with the first guide grooves (53) and the second guide grooves (58). The first guide grooves (53) and the second guide grooves (58) extend along the convergence direction of the sealing plate (55). The transmission assembly includes a second drive gear (5), a second transmission gear (51), a fixed sleeve (4), a transmission gear disc (45), a third hydraulic rod (41), a damping ring (42), a hexagonal rod (43), and a connecting gear disc (44). The fixed sleeve (4) is fixedly connected to the bottom of the outer wall of the second limiting plate (22). The second transmission gear (51) is rotatably mounted on the second limiting plate (22) and meshes with the second gear disc (52) and the second drive gear (5) respectively. The transmission gear disc (45) is fixedly connected to the first drive gear. The gear (31) is located on the outer wall away from the motor (3). The third hydraulic rod (41) is fixedly connected to the inner side of the fixed sleeve (4). The output end of the third hydraulic rod (41) is rotatably connected to the damping ring (42). The damping ring (42) is rotatably connected to the hexagonal rod (43) on the side away from the fixed sleeve (4). The second driving gear (5) is sleeved on the hexagonal rod (43). The end of the hexagonal rod (43) is fixedly connected to the connecting gear plate (44). The connecting gear plate (44) is engaged with the transmission gear plate (45).

2. The laser welding apparatus for welding steel pipes as claimed in claim 1, characterized in that, The first gas outlet assembly includes a nitrogen cylinder (71), a first connecting pipe (72), a second gas pump (73), a first delivery pipe (74), a second annular pipe (8), and a gas guide ring (81). A slot (7) is provided on the outer wall of the first limiting plate (21). The nitrogen cylinder (71) is detachably connected to the inner side of the slot (7). The gas outlet end of the nitrogen cylinder (71) is fixedly connected to the first connecting pipe (72). The top end of the first connecting pipe (72) is fixedly connected to the second gas pump (73). The output end of the second gas pump (73) is fixedly connected to the first delivery pipe (74). The bottom end of the first delivery pipe (74) is fixedly connected to the second annular pipe (8). The gas guide ring (81) is fixedly connected to the inner side of the second annular pipe (8). The gas guide ring (81) is fixedly connected to the inner side of the gas guide ring (81) with evenly distributed partitions (82) and multiple guide plates (83) are fixedly connected to the inner side of the gas guide ring (81).

3. The laser welding apparatus for welding steel pipes as claimed in claim 1, characterized in that, The first air intake assembly includes a third air pump (9), an air outlet pipe (91), a filter device, and a second delivery pipe (92); the third air pump (9) is fixedly connected to the inner top of the second limiting plate (22), the air outlet end of the third air pump (9) is fixedly connected to the air outlet pipe (91), the air outlet pipe (91) is externally connected to the filter device, the air intake end of the third air pump (9) is fixedly connected to the second delivery pipe (92), and the bottom end of the second delivery pipe (92) is fixedly connected to a second annular pipe (8), an air guide ring (81), a partition plate (82), and a flow guide plate (83), which are the same as those in the first air intake assembly.

4. The laser welding apparatus for welding steel pipes as claimed in claim 3, characterized in that, The second air outlet assembly includes a first guide pipe (6), a split pipe (62), a first air pump (63), a connecting tube (64), and an air delivery pipe (65); the first guide pipe (6) is fixedly connected to the outer wall of the air guide ring (81) near the second air pump (73), and an air outlet (61) is fixedly connected to the side of the first guide pipe (6) away from the second annular pipe (8), the split pipe (62) is fixedly connected to the outer wall of the first guide pipe (6), the first air pump (63) is fixedly connected to the bottom end of the split pipe (62), the connecting tube (64) is fixedly connected to the air inlet end of the first air pump (63), the air delivery pipe (65) is fixedly connected to the outer wall of the connecting tube (64), and the air delivery pipe (65) is fixedly connected to the outer wall of the second limiting plate (22) on the same side.

5. The laser welding apparatus for welding steel pipes as claimed in claim 4, characterized in that, The second air intake assembly includes a second guide pipe (69), a manifold (68), a filter element (66), and a second connecting sleeve (67). The second guide pipe (69) is fixedly connected to the outer wall of the air guide ring (81) on the side close to the third air pump (9). An air inlet (610) is fixedly connected to the outer wall of the second guide pipe (69) away from the third air pump (9). The manifold (68) is fixedly connected to the outer wall of the second guide pipe (69). The filter element (66) is detachably connected to the bottom end of the manifold (68). The second connecting sleeve (67) is fixedly connected to the outer wall of the filter element (66). The second connecting sleeve (67) is fixedly connected to the second limiting plate (22) on the adjacent side. The connecting tube (64) is slidably connected to the filter element (66). The air supply pipe (65) is slidably connected to the second connecting sleeve (67).

6. The laser welding apparatus for welding steel pipes as claimed in claim 1, characterized in that, The clamping assembly includes a second fixing frame (34) fixedly connected to the end face of the first gear plate (33), a second hydraulic rod (35) mounted on the second fixing frame (34), and a clamping plate (36) mounted on the output end of the second hydraulic rod (35).

7. The laser welding apparatus for welding steel pipes as claimed in claim 1, characterized in that, The two clamping mechanisms (30) and the two circumferential sealing mechanisms (40) are arranged in a one-to-one manner to form two modules. At least one of the modules is provided with a sliding assembly between it and the main frame (1). The main frame (1) is provided with a first hydraulic rod (12) that drives the module to move axially along the steel pipe.

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