Automatic welding equipment and method for inner girth weld of large-diameter steel pipe

Abstract

The application discloses a kind of inner girth weld automatic welding equipment and inner girth weld automatic welding method of large diameter steel pipe, including equipment host, welding working device and connecting device, equipment host and / or welding working device are equipped with walking mechanism, connecting device includes the first connecting plate connected with equipment host, the second connecting plate connected with welding working device and the offset mechanism for connecting the first connecting plate and the second connecting plate and making the second connecting plate can be offset relative to the radial plane of steel pipe, equipment host is equipped with first positioning mechanism, and welding working device is equipped with second positioning mechanism;The offset function of connecting mechanism can reduce vibration, avoid equipment host vibration to influence the work and operation of welding working device, to ensure welding quality, and adapt to the axis of two steel pipes not coinciding, steel pipe straightness, roundness not meeting the standard case walking and positioning, so that the inner girth weld automatic welding equipment of large diameter steel pipe can still complete automatic welding.

Description

Technical Field

[0001] The present invention relates to the technical field of pipeline welding, and in particular to an automatic inner girth seam welding device for large-diameter steel pipes. Furthermore, the present invention also relates to an automatic inner girth seam welding method for large-diameter steel pipes, comprising utilizing the automatic inner girth seam welding device for large-diameter steel pipes. Background Art

[0002] In on-site fabrication and installation of steel pipes for water conservancy and hydropower projects, the pipes are typically welded into sections of less than 6 meters. The pipes are then transported to the installation site using dedicated trailers or rail-mounted trolleys for assembly and welding. On-site welding requires high quality, is labor-intensive, and presents a complex welding process. Currently, welding of steel pipe assembly seams is primarily done manually, which is labor-intensive, has inconsistent quality, and is inefficient. Traditional manual welding can no longer meet the demands of on-site construction.

[0003] To improve welding efficiency, automatic welding equipment for the internal circumferential seam of steel pipes has emerged. Since the assembly of steel pipes relies on rail-mounted trolleys, it is difficult to adjust the angle, roundness, assembly spacing, and axis overlap of the two sections of steel pipes during the assembly process. This can lead to problems such as misalignment between the axes of the steel pipes and failure to meet required roundness.

[0004] For example, Chinese patent CN216730166 U discloses an automatic welding device for steel pipes in tunnels. By providing a circular sliding assembly, the welding gun can move circumferentially along the inner wall of a large steel pipe in the tunnel, thereby automatically welding the circular end face of the steel pipe. On the one hand, as construction progresses, the welding work station will constantly change, and the automatic welding device cannot move independently, making construction inside the steel pipe very inconvenient and reducing the efficiency of the overall welding construction. On the other hand, because the slide rail can be attached to the inner wall of the steel pipe in the tunnel through a positioning module, when the roundness of the steel pipe does not meet the requirements, the circular track is difficult to lay, resulting in the inability to effectively implement welding.

[0005] Another example is a steel pipe welding trolley disclosed in Chinese patent CN201685037 U. A reducer drives a rotating support frame, which rotates the steel pipe. A welding operation frame mounted on a crossbeam performs circumferential welding, enabling on-site assembly and fabrication of long or multiple steel pipes. Because the reducer, welding operation frame, and electromechanical control system are mounted on the crossbeam, vibration from the reducer during rotation can affect the normal welding process, resulting in poor weld quality. Summary of the Invention

[0006] The present invention provides an automatic welding device and method for the inner girth seam of a large-diameter steel pipe, so as to solve the technical problems of the automatic welding equipment in the prior art, such as the inconvenience of construction inside the steel pipe, the difficulty of application when the axes between the steel pipes do not coincide, the roundness of the steel pipes exceeds the standard, and the poor welding quality.

[0007] According to one aspect of the present invention, there is provided an automatic welding device for the inner annular seam of a large-diameter steel pipe, comprising an equipment main unit for providing power, a welding working device and a connecting device for welding the inner annular seam, the equipment main unit and / or the welding working device being provided with a walking mechanism, the connecting device comprising a first connecting plate connected to the equipment main unit, a second connecting plate connected to the welding working device and an offset mechanism for connecting the first connecting plate and the second connecting plate and enabling the second connecting plate to be offset relative to the radial plane of the steel pipe, the equipment main unit being provided with a first positioning mechanism for fixing the position of the equipment main unit along the axial direction of the steel pipe, and the welding working device being provided with a second positioning mechanism for keeping the welding working device coaxial with the steel pipe.

[0008] Furthermore, the offset mechanism includes a first sleeve arranged on the first connecting plate, a second sleeve arranged on the second connecting plate, a sliding rod slidably connected to the first sleeve and the second sleeve, and a buffer member sleeved on the sliding rod, and limit blocks are respectively arranged at both ends of the sliding rod to prevent the sliding rod from slipping. The inner diameters of the first sleeve and the second sleeve are larger than the outer diameter of the sliding rod to form an offset gap.

[0009] Furthermore, the walking mechanism includes a driving wheel arranged on the equipment main body, a telescopic wheel group arranged on the equipment main body and retractable in the horizontal direction, a first guide wheel group arranged on the equipment main body, a second guide wheel group arranged on the welding work device and a lifting mechanism for driving the telescopic wheel group to move in the vertical direction.

[0010] Furthermore, the first guide wheel group and the second guide wheel group are both distributed in an eight-shaped shape.

[0011] Furthermore, the first positioning mechanism includes a side main support mechanism arranged on the main body of the equipment and capable of being extended and retracted in the horizontal direction to abut against the inner wall of the steel pipe, and a side auxiliary support mechanism arranged on the main body of the equipment and capable of being extended and retracted in the horizontal direction to abut against the inner wall of the steel pipe. The side main support mechanism includes a first support cylinder that can be extended and retracted in the horizontal direction and an arc-shaped support block arranged on the free end of the first support cylinder and adapted to the inner wall of the steel pipe. The side auxiliary support mechanism has the same structure as the side main support mechanism.

[0012] Furthermore, the side main support mechanism is arranged on the end of the device main body away from the telescopic wheel group, and the side auxiliary support mechanism is arranged on the end of the device main body close to the telescopic wheel group, and the support area of ​​the arc support block on the side main support mechanism is larger than the support area of ​​the arc support block on the side auxiliary support mechanism.

[0013] Furthermore, the second positioning mechanism includes an annular positioning frame arranged on the welding work device, second supporting cylinders evenly arranged along the circumference of the annular positioning frame, a balancing frame arranged on the free end of the second supporting cylinder, a ball arranged on the balancing frame, and a pressure sensor for monitoring the oil pressure of the second supporting cylinder. The free end of the second supporting cylinder is connected to the balancing frame through a universal joint, and the second supporting cylinder and the pressure sensor are arranged in a one-to-one correspondence.

[0014] Furthermore, the welding working device includes a track mechanism, a welding robotic arm, a connecting sleeve and a welding wire feeding mechanism, the track mechanism includes a circular track arranged on the connecting sleeve 23, a driving rack arranged on the circular track, and a mobile trolley arranged on the driving rack, the welding robotic arm includes a robotic arm arranged on the mobile trolley, a welding gun and a visual system arranged on the robotic arm, the welding wire feeding mechanism includes a side frame connected to the connecting device, the side frame is provided with the wire feeder, the wire reel and the gun cleaner, one end of the connecting sleeve is connected to the side frame, and the other end is connected to the annular positioning frame.

[0015] Furthermore, the equipment host includes a host body, on which a power supply, an electric control box, a pump station and a mounting plate for connecting the connecting device are arranged.

[0016] According to another aspect of the present invention, a method for automatically welding the inner girth seam of a large-diameter steel pipe is provided, which utilizes the above-mentioned automatic welding equipment for welding the inner girth seam of a large-diameter steel pipe, and comprises the following steps:

[0017] S1. Adjust the installation position of the connecting device and the side frame and the extension length of the second positioning mechanism according to the diameter of the steel pipe to be welded, and adjust the lifting mechanism so that the horizontal extension direction of the telescopic wheel group coincides with the horizontal radial direction of the steel pipe to be welded;

[0018] S2, retract the first supporting oil cylinder, retract the telescopic wheel group and the second supporting oil cylinder, hoist the large diameter steel pipe inner ring seam automatic welding equipment into the assembled steel pipe to be welded,

[0019] S3. Extend the telescopic wheel assembly so that it rolls with the inner wall of the steel pipe to be welded. Extend the second supporting oil cylinder so that the ball bearings on the balance frame at the bottom end of the annular positioning frame roll with the inner wall of the steel pipe to be welded. Start the traveling mechanism to drive the automatic welding equipment for the inner annular seam of the large-diameter steel pipe to the work site, ensuring that the distance between the welding robot arm and the weld is within a preset range.

[0020] S4. Extend the first supporting cylinder so that the arc-shaped supporting block of the side main supporting mechanism and the arc-shaped supporting block of the side auxiliary supporting mechanism abut against the inner wall of the steel pipe to be welded, and adjust and fix the relative position of the main unit of the equipment and the steel pipe to be welded;

[0021] S5. Extend the second supporting oil cylinder so that the balls on all the balancing frames contact the inner wall of the steel pipe to be welded, thereby positioning the relative position of the welding working device and the steel pipe to be welded;

[0022] S6. Start the visual system to check the track mechanism, the positioning of the welding robot arm, and the equipment status of the wire feeder, robot arm, and welding gun.

[0023] S7. Perform pre-welding preparations, including grinding and preheating the circumferential seam;

[0024] S8, Circumferential seam automated welding and root cleaning;

[0025] S9, weld post-processing, completing the welding of a circumferential seam;

[0026] S10, retract the second supporting cylinder to keep the ball bearings of the balance frame at the bottom end of the annular positioning frame in rolling connection with the inner wall of the steel pipe to be welded, and retract the first supporting cylinder to disengage the arcuate supporting blocks of the side main supporting mechanism and the arcuate supporting blocks of the side auxiliary supporting mechanism from contact with the inner wall of the steel pipe to be welded;

[0027] S11. Repeat steps S3 to S10 to weld the next circumferential seam.

[0028] The present invention has the following beneficial effects:

[0029] The automatic inner girth welding equipment for large-diameter steel pipes of the present invention drives the entire equipment forward or backward in the steel pipe through a walking mechanism, which is convenient for adjusting the relative position between the equipment and the girth weld of the steel pipe; when the equipment moves to the working point, the relative position of the equipment main unit and the steel pipe is positioned by the first positioning mechanism, and the relative position of the welding working device and the steel pipe is positioned by the second positioning mechanism. Since the second connecting plate of the connecting mechanism can be offset relative to the radial plane of the steel pipe, on the one hand, the positioning of the welding working device can be effectively adjusted and is not affected by the positioning of the equipment main unit, and can prevent the welding working device and the standby main unit from being positioned out of center and causing torsional damage to the connecting mechanism. On the other hand, vibration reduction can be achieved through the connecting mechanism to avoid the vibration of the equipment main unit affecting the work and operation of the welding working device, thereby ensuring the welding quality. In addition, the offset function of the connecting mechanism can adapt to walking and positioning when the axes of the two sections of steel pipes do not coincide, the straightness of the steel pipes exceeds the standard, and the roundness does not meet the standard, so that the automatic inner girth welding equipment for large-diameter steel pipes can still complete automatic welding; it is suitable for automatic welding of all-position inner girth welds in the tunnel position of 2-3 meter diameter steel pipes.

[0030] In addition to the above-described objects, features and advantages, the present invention has other objects, features and advantages. The present invention will be further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0032] Figure 1 2. It is a schematic structural diagram of an automatic welding device for inner girth seams of large-diameter steel pipes according to a preferred embodiment of the present invention;

[0033] Figure 2 This is a schematic structural diagram of another perspective of the automatic welding equipment for the inner girth seam of a large-diameter steel pipe according to a preferred embodiment of the present invention;

[0034] Figure 3 This is a schematic structural diagram of a device host according to a preferred embodiment of the present invention;

[0035] Figure 4 is a structural schematic diagram of a first positioning mechanism according to a preferred embodiment of the present invention;

[0036] Figure 5 1 is a structural diagram of a welding working device according to a preferred embodiment of the present invention;

[0037] Figure 6 1 is a structural diagram of a welding robot arm according to a preferred embodiment of the present invention;

[0038] Figure 71 is a structural diagram of a welding wire feeding mechanism according to a preferred embodiment of the present invention;

[0039] Figure 8 is a structural schematic diagram of a connecting device according to a preferred embodiment of the present invention;

[0040] Figure 9 Schematic diagram of the structure of the walking mechanism of the preferred embodiment of the present invention;

[0041] Figure 10 It is a structural schematic diagram of the second positioning mechanism of the preferred embodiment of the present invention.

[0042] Legend:

[0043] 100. Steel pipe; 1. Equipment host; 11. Host body; 12. Power supply; 13. Electric control box; 14. Pump station; 15. Mounting plate; 16. Maintenance door; 17. Gas cylinder storage area; 18. Robotic arm control cabinet; 2. Welding work device; 21. Welding robot arm; 211. Robotic arm; 212. Welding gun; 22. Track mechanism; 221. Circular track; 222. Drive rack; 223. Mobile trolley; 23. Connecting sleeve; 24. Welding wire feeder mechanism; 241. Side joint frame; 242. Wire feeder; 243. Wire reel; 244. Inspection port; 3. Connecting device; 31. First Connecting plate; 32. Second connecting plate; 33. Offset mechanism; 331. First sleeve; 332. Second sleeve; 333. Slide rod; 334. Buffer; 335. Limit block; 4. Traveling mechanism; 41. Driving wheel; 42. Telescopic wheel group; 43. First guide wheel group; 44. Second guide wheel group; 5. First positioning mechanism; 51. Side main support mechanism; 52. Side auxiliary support mechanism; 511. First supporting cylinder; 512. Arc support block; 6. Second positioning mechanism; 61. Annular positioning frame; 62. Second supporting cylinder; 63. Balancing frame; 64. Ball; 65. Universal joint. DETAILED DESCRIPTION

[0044] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

[0045] Please also refer to Figures 1 to 10The automatic inner girth seam welding equipment for large-diameter steel pipes of this embodiment includes an equipment main body 1 for providing power, a welding work device 2 for welding inner girth seams, and a connecting device 3. A walking mechanism 4 is arranged on the equipment main body 1 and / or the welding work device 2. The connecting device 3 includes a first connecting plate 31 connected to the equipment main body 1, a second connecting plate 32 connected to the welding work device 2, and an offset mechanism 33 for connecting the first connecting plate 31 and the second connecting plate 32 and allowing the second connecting plate 32 to be offset relative to the radial plane of the steel pipe 100. A first positioning mechanism 5 for fixing the axial position of the equipment main body 1 along the steel pipe 100 is arranged on the equipment main body 1, and a second positioning mechanism 6 for keeping the welding work device 2 and the steel pipe 100 coaxial is arranged on the welding work device 2.

[0046] The automatic welding equipment for the inner girth seam of a large-diameter steel pipe of this embodiment drives the entire equipment forward or backward in the steel pipe 100 through the walking mechanism 4, so as to facilitate adjustment of the relative position between the equipment and the girth weld of the steel pipe; when the equipment moves to the working point, the relative position of the equipment main body 1 and the steel pipe 100 is positioned by the first positioning mechanism 5, and the relative position of the welding working device 2 and the steel pipe 100 is positioned by the second positioning mechanism 6. Since the second connecting plate 32 of the connecting mechanism 3 can be offset relative to the radial plane of the steel pipe 100, on the one hand, the positioning of the welding working device 2 can be effectively adjusted without being affected by the positioning of the equipment main body 1 Influence, can prevent the welding work device 2 and the standby host 1 from positioning out of center and causing torsional damage to the connecting mechanism 3. On the other hand, vibration reduction can be achieved through the connecting mechanism 3 to avoid the vibration of the equipment host 1 affecting the work and operation of the welding work device 2, thereby ensuring the welding quality. In addition, the offset function of the connecting mechanism 3 can adapt to walking and positioning when the axes of the two sections of steel pipes do not coincide, the straightness of the steel pipes exceeds the standard, and the roundness does not meet the standard, so that the automatic welding equipment for the inner girth seam of large-diameter steel pipes can still complete automatic welding; it is suitable for automatic welding of the inner girth seam in the tunnel position of 2-3 meters diameter steel pipes in all positions.

[0047] Optionally, the offset mechanism 33 is a universal joint, which has a simple structure and low production cost.

[0048] like Figure 7 and Figure 8As shown, in this embodiment, the offset mechanism 33 includes a first sleeve 331 arranged on the first connecting plate 31, a second sleeve 332 arranged on the second connecting plate 32, a sliding rod 333 slidably connected to the first sleeve 331 and the second sleeve 332, and a buffer member 334 sleeved on the sliding rod 333, and two ends of the sliding rod 333 are respectively provided with a limit block 335 for preventing the sliding rod 333 from slipping. The inner diameters of the first sleeve 331 and the second sleeve 332 are larger than the outer diameter of the sliding rod 333 to form an offset gap; the sliding rod 333 slides relative to the first sleeve 331 and the second sleeve 332 in the axial direction, and there is also an offset space in its radial direction. When the axis of the pipes do not coincide, and the straightness and roundness of the steel pipes do not meet the standards, the first positioning mechanism 5 and the second positioning mechanism 6 are positioned respectively, so that the second connecting plate 32 and the offset mechanism 33 that enables the second connecting plate 32 to be offset relative to the radial plane of the steel pipe 100 are provided to prevent torsional damage to the connecting mechanism 3 when the positioning is not concentric; when welding is completed, the first positioning mechanism 5 and the second positioning mechanism 6 cancel the positioning, and the buffer 334 can drive the second connecting plate 32 to reset; by selecting the size of the first sleeve 331, the second sleeve 332 and the slide rod 333, the offset gap can be adjusted, thereby limiting the offset of the second connecting plate 32 and preventing excessive offset displacement. Optionally, the buffer 334 is a spring, an elastic bellows or a rubber sleeve. Optionally, multiple offset mechanisms 33 are evenly arranged along the circumferential direction.

[0049] like Figure 3 、 Figure 4 and Figure 5 As shown, in this embodiment, the walking mechanism 4 includes a driving wheel 41 arranged on the main body 1 of the equipment, a telescopic wheel group 42 arranged on the main body 1 and capable of being telescopic in the horizontal direction, a first guide wheel group 43 arranged on the main body 1 of the equipment, a second guide wheel group 44 arranged on the welding working device 2, and a lifting mechanism for driving the telescopic wheel group 42 to move in the vertical direction; the first guide wheel group 43 and the driving wheel 41 support the main body 1 of the equipment, the first guide wheel group 43 supports the welding working device 2, and the driving wheel 41 drives the entire equipment to move on the steel pipe 10 0 forward and backward, which is convenient for moving the working point and adjusting the relative position between the entire equipment and the steel pipe girth weld during welding; two telescopic wheel groups 42 are symmetrically arranged on both sides of the equipment main body 1, and each telescopic wheel group 42 includes two first rollers arranged up and down. When constructing steel pipes of different diameters, the telescopic wheel group 42 adjusts its height in the steel pipe 100 through the lifting mechanism to ensure that the two first rollers arranged up and down are symmetrical with respect to the horizontal radial direction of the steel pipe 100, thereby ensuring that the equipment can move stably in steel pipes 100 of different diameters.

[0050] like Figure 5 and Figure 9As shown, in this embodiment, the first guide wheel group 43 and the second guide wheel group 44 are both distributed in an eight-shaped shape. The first guide wheel group 43 includes two second rollers, which are distributed in an eight-shaped shape and are symmetrically arranged in the vertical diameter direction relative to the steel pipe 100. The supporting force of the inner wall of the steel pipe 100 on the second roller can be decomposed into a vertical component and a horizontal component, which can improve the stability of the equipment host 1. The second guide wheel group 44 has the same structure as the first guide wheel group 43, which can improve the stability of the welding work device 2, thereby ensuring the welding quality.

[0051] like Figure 3 and Figure 4 As shown, in this embodiment, the first positioning mechanism 5 includes a side main support mechanism 51 arranged on the equipment main body 1 and capable of being extended and retracted in the horizontal direction to abut the inner wall of the steel pipe 100, and a side auxiliary support mechanism 52 arranged on the equipment main body 1 and capable of being extended and retracted in the horizontal direction to abut the inner wall of the steel pipe 100. The side main support mechanism 51 includes a first supporting cylinder 511 that can be extended and retracted in the horizontal direction and an arc-shaped support block 512 arranged on the free end of the first supporting cylinder 511 and adapted to the inner wall of the steel pipe 100. The side auxiliary support mechanism 52 has the same structure as the side main support mechanism 51; the first supporting cylinders 511 of the side main support mechanism 51 and the side auxiliary support mechanism 52 are extended so that the arc-shaped support block 512 abuts the inner wall of the steel pipe 100, which can ensure that the equipment main body 1 is stably and reliably fixed in the steel pipe 100 to be welded, avoiding affecting the working environment of the welding mechanism.

[0052] like Figure 3 and Figure 4 As shown, in this embodiment, the side main support mechanism 51 is arranged on the end of the equipment main body 1 away from the telescopic wheel group 42, and the side auxiliary support mechanism 52 is arranged on the end of the equipment main body 1 close to the telescopic wheel group 42. The support area of ​​the arc support block 512 on the side main support mechanism 51 is larger than the support area of ​​the arc support block 512 on the side auxiliary support mechanism 52; due to the supporting function of the telescopic wheel group 42, the side auxiliary support mechanism 52 can use a smaller arc support block 512, which can correspondingly reduce the parameters of the first supporting cylinder 511 of the side auxiliary support mechanism 52, thereby reducing costs; and the horizontal component force provided by the first guide wheel group 43 on one side of the side main support mechanism 51 is relatively small, so a large cylinder is selected to provide a larger supporting force to ensure the positioning stability, and the inner wall surface of the steel pipe 100 is coated. In order to prevent the arc support block 512 of the side main support mechanism 51 from damaging the coating, increasing the area of ​​the arc support block 512 can disperse the pressure, thereby protecting the coating on the inner wall surface of the steel pipe 100.

[0053] like Figure 10As shown, in this embodiment, the second positioning mechanism 6 includes an annular positioning frame 61 arranged on the welding work device 2, second supporting oil cylinders 62 uniformly arranged along the circumference of the annular positioning frame 61, a balancing frame 63 arranged on the free end of the second supporting oil cylinder 62, a ball 64 arranged on the balancing frame 63 and a pressure sensor for monitoring the oil pressure of the second supporting oil cylinder 62. The free end of the second supporting oil cylinder 62 is connected to the balancing frame 63 through a universal joint 65, and the second supporting oil cylinder 62 and the pressure sensor are arranged one by one; the multiple second supporting oil cylinders 62 are synchronously telescopic, and the balancing frame 63 and the first The free ends of the two supporting cylinders 62 are connected by a universal joint 65, and the four balls 64 on the balance frame 63 are rollingly connected to the inner wall of the steel pipe 100. During positioning, each second supporting cylinder 62 relies on pressure sensing to automatically adjust the support extension length. The four balls 64 can share the pressure of the second supporting cylinder 62 to avoid damage to the coating on the inner wall of the steel pipe 100. The universal joint 65 can enable the balance frame 63 to be offset, thereby adapting to the working condition when the roundness of the steel pipe exceeds the standard to a certain extent. The positioning is reliable and ensures that the track mechanism 22 of the welding work device 2 is closer to the coaxiality of the steel pipe 100.

[0054] like Figure 5 、 Figure 6 and Figure 7As shown, in this embodiment, the welding working device 2 includes a track mechanism 22, a welding robot arm 21, a connecting sleeve 23 and a welding wire feeding mechanism 24, the track mechanism 22 includes an annular track 221 arranged on the connecting sleeve 23, a driving rack 222 arranged on the annular track 221, and a mobile carriage 223 arranged on the driving rack 222, the welding robot arm 21 includes a robot arm 211 arranged on the mobile carriage 223, a welding gun 212 and a visual system arranged on the robot arm 211, the welding wire feeding mechanism 24 includes a side frame 241 connected to the connecting device 3, and a wire feeder 242, a welding wire reel 243 and a gun cleaner are arranged on the side frame 241, one end of the connecting sleeve 23 is connected to the side frame 241, and the other end is connected to the annular positioning frame 61; the side frame 241 and the connecting sleeve 23 are connected to the annular positioning frame 61; The annular positioning frame 61 is coaxially connected, and the balance frame 63 on the annular positioning frame 61 can produce an offset, which is not affected by the roundness of the steel pipe 100, ensuring that the second positioning mechanism 6 accurately positions the welding work device 2, the positioning is reliable, and the track mechanism 22 of the welding work device 2 is closer to the coaxiality of the steel pipe 100, thereby reducing the recognition distance deviation of the visual system, thereby ensuring the quality of automatic welding of the steel pipe circumferential seam. The robot arm 211 moves in a circle on the annular track 221 through the mobile trolley 223. The welding efficiency distribution of each robot arm 211 can be adjusted at will, and the robot arm 211 will not be idle, and the welding efficiency is high. The wire feeder 242, the wire reel 243 and the gun cleaner are arranged at the welding working end of the side frame 241, which is convenient for the personnel at the working end to observe and replace consumables such as welding wire. Optionally, the robot arm 211 is a six-axis robot arm with flexible operation and wide applicability. Optionally, three mobile carriages 223 are disposed on the drive rack 222, each of which is equipped with a welding robot arm 21. This allows for segmented welding, as well as layered or circular welding. This flexible operation allows for diverse adaptability, effectively distributing the workload when welding circular welds, and improving the utilization and efficiency of the welding device 2. Optionally, an inspection port 244 is provided on the side frame 241 for easy inspection and maintenance.

[0055] like Figure 3 and Figure 4As shown, in this embodiment, the equipment main unit 1 includes a main unit body 11, which is equipped with a power supply 12, an electrical control box 13, a pump station 14, and a mounting plate 15 for connecting the connecting device 3. The main unit body 11 serves as a frame, and the mounting plate 15 is connected to the first connecting plate 31. The power supply 12 provides power to the entire internal girth seam automatic welding equipment. The electrical control box 13 is used for controlling and processing data for the welding working device 2, the traveling mechanism 4, the first positioning mechanism 5, and the second positioning mechanism 6. The electrical control box 13 is located at the rear end of the main unit body 11 for centralized maintenance. The pump station 14 provides pressurized oil for the entire internal girth seam automatic welding equipment. Optionally, a maintenance door 16 is provided on the main unit body 11 to facilitate maintenance personnel. Optionally, a gas cylinder storage area 17 is provided on the main unit body 11, in which gas cylinders are placed to provide a high-pressure gas source for the entire internal girth seam automatic welding equipment. Optionally, a robotic arm control cabinet 18 is provided on the main body 11. The control cabinet for the welding device 2 is separately located within the main body 11. This simplifies the wiring layout within the electrical control box 13 and facilitates separate maintenance and adjustment of the control system for the welding robotic arm 21. Optionally, an operating box and / or a remote control computer or remote controller may be located within the electrical control box 13.

[0056] A method for automatically welding the inner girth seam of a large-diameter steel pipe, using the aforementioned automatic welding equipment for the inner girth seam of a large-diameter steel pipe, comprises the following steps:

[0057] S1. Adjust the installation positions of the connecting device 3 and the side connection frame 241 and the extension length of the second positioning mechanism 6 according to the diameter of the steel pipe 100 to be welded, so that the annular positioning frame 61 of the second positioning mechanism 6 is coaxial with the steel pipe 100 to be welded. Adjust the lifting mechanism so that the horizontal extension direction of the telescopic wheel group 42 coincides with the horizontal radial direction of the steel pipe 100 to be welded;

[0058] S2, retract the first supporting cylinder 511, retract the telescopic wheel group 42 and the second supporting cylinder 62, and hoist the large diameter steel pipe inner ring seam automatic welding equipment into the assembled steel pipe to be welded 100,

[0059] S3. Extend the telescopic wheel assembly 42 so that the telescopic wheel assembly 42 is in rolling connection with the inner wall of the steel pipe 100 to be welded. Extend the second supporting oil cylinder 62 so that the ball 64 of the balance frame 63 at the bottom end of the annular positioning frame 61 is in rolling connection with the inner wall of the steel pipe 100 to be welded. Start the traveling mechanism 4 to drive the automatic welding equipment for the inner annular seam of the mobile large-diameter steel pipe to move to the work site, ensuring that the distance between the welding robot arm 21 and the weld is within a preset range.

[0060] S4. Extend the first supporting cylinder 511 so that the arc-shaped supporting block 512 of the side main supporting mechanism 51 and the arc-shaped supporting block 512 of the side auxiliary supporting mechanism 52 abut against the inner wall of the steel pipe 100 to be welded, thereby adjusting and fixing the relative position of the main unit 1 and the steel pipe 100 to be welded;

[0061] S5. Extend the second supporting cylinder 62 so that the balls 64 on all the balancing frames 63 abut against the inner wall of the steel pipe 100 to be welded, thereby positioning the relative position of the welding device 2 and the steel pipe 100 to be welded;

[0062] S6. Start the visual system to check the positioning of the track mechanism 22, the welding robot arm 21, and the equipment status of the wire feeder 242, the robot arm 211, and the welding gun 212.

[0063] S7. Perform pre-welding preparations, including grinding and preheating the circumferential seam;

[0064] S8, Circumferential seam automated welding and root cleaning;

[0065] S9, weld post-processing, completing the welding of a circumferential seam;

[0066] S10, retract the second supporting cylinder 62, keep the ball 64 of the balance frame 63 at the bottom end of the annular positioning frame 61 in rolling connection with the inner wall of the steel pipe 100 to be welded, and retract the first supporting cylinder 511, so that the arc-shaped support block 512 of the side main support mechanism 51 and the arc-shaped support block 512 of the side auxiliary support mechanism 52 are out of contact with the inner wall of the steel pipe 100 to be welded;

[0067] S11. Repeat steps S4 to S10 to weld the next circumferential seam.

[0068] The present invention adopts a welding robot arm 21 to realize the automated welding of the annular seam of the inner wall of the steel pipe. The welding robot arm 21 is a programming-free welding method. It adopts a visual system to accurately identify the geometric shape of the groove, the robot automatically plans the position and posture, and independently realizes the robot swing welding and variable parameter process package, realizes the robot swing welding mode and path customization, and adjusts the parameters such as current and voltage during the welding process, effectively solves the variable gap and thermal deformation compensation adaptive control, and finally realizes full-position fully automatic welding; the second positioning mechanism 6 installed in conjunction with the welding robot arm 21 is a ring positioning device, which can fix the welding work device 2 and position the axis line of the welding work device 2 near the axis line of the steel pipe, thereby reducing the recognition distance deviation of the visual system; the multiple second support cylinders 62 of the second positioning mechanism 6 are synchronously retractable, and each second support cylinder 62 relies on pressure sensing to automatically adjust the support extension length, which is reliable and ensures that the coaxiality of the welding mechanism and the steel pipe is closer; the walking mechanism 4 drives the entire The equipment can move freely in the steel pipe, realizing forward and backward functions, which is convenient for moving the working point and adjusting the relative position between the equipment and the steel pipe ring weld during welding; when constructing steel pipes of different diameters, the height of the telescopic wheel group 42 can be adjusted to ensure that the telescopic wheel group 42 can adapt to stable movement within different steel pipe diameters; the first positioning mechanism 5 can ensure that when the welding work device 2 is working, the main unit 1 of the equipment is stably and reliably fixed in the steel pipe to be welded, without affecting the working environment of the welding mechanism; since the main unit 1 of the equipment and the welding work device 2 respectively have their own positioning mechanisms, the connecting mechanism 3 adopts a flexible connection method to connect the main unit 1 of the equipment and the welding work device 2, which can ensure that the relative position of the first connecting plate 31 and the second connecting plate 32 is adjustable and does not separate from each other, and prevents torsional damage to the connecting mechanism 3 when the positioning is not concentric; the installation position of the side frame 241 and the second connecting plate can be adjusted, thereby adjusting the relative position of the welding work device 2 and the main unit 1 of the equipment to adapt to different steel pipe diameters.

[0069] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. An automatic welding device for the inner girth seam of a large diameter steel pipe, characterized in that: The invention comprises an equipment main body (1) for providing power, a welding working device (2) for welding an inner annular seam, and a connecting device (3); a walking mechanism (4) is arranged on the equipment main body (1) and / or the welding working device (2); the connecting device (3) comprises a first connecting plate (31) connected to the equipment main body (1), a second connecting plate (32) connected to the welding working device (2), and an offset mechanism (33) for connecting the first connecting plate (31) and the second connecting plate (32) and enabling the second connecting plate (32) to be offset relative to the radial plane of the steel pipe; a first positioning mechanism (5) for fixing the position of the equipment main body (1) along the axial direction of the steel pipe is arranged on the equipment main body (1); a second positioning mechanism (6) for keeping the welding working device (2) and the steel pipe coaxial is arranged on the welding working device (2); The offset mechanism (33) includes a first sleeve (331) arranged on the first connecting plate (31), a second sleeve (332) arranged on the second connecting plate (32), a sliding rod (333) slidably connected to the first sleeve (331) and the second sleeve (332), and a buffer (334) sleeved on the sliding rod (333). Limiting blocks (335) for preventing the sliding rod (333) from slipping are arranged at both ends of the sliding rod (333). The inner diameters of the first sleeve (331) and the second sleeve (332) are larger than the outer diameter of the sliding rod (333) to form an offset gap. The second positioning mechanism (6) includes an annular positioning frame (61) arranged on the welding work device (2), second supporting oil cylinders (62) uniformly arranged along the circumference of the annular positioning frame (61), a balancing frame (63) arranged on the free end of the second supporting oil cylinder (62), a ball (64) arranged on the balancing frame (63), and a pressure sensor for monitoring the oil pressure of the second supporting oil cylinder (62), the free end of the second supporting oil cylinder (62) is connected to the balancing frame (63) through a universal joint (65), and the second supporting oil cylinder (62) and the pressure sensor are arranged in a one-to-one correspondence. The welding working device (2) comprises a track mechanism (22), a welding mechanical arm (21), a connecting sleeve (23) and a welding wire feeding mechanism (24); the welding wire feeding mechanism (24) comprises a side frame (241) connected to the connecting device (3); one end of the connecting sleeve (23) is connected to the side frame (241), and the other end is connected to the annular positioning frame (61).

2. The automatic welding equipment for inner girth seams of large diameter steel pipes according to claim 1, characterized in that: The walking mechanism (4) comprises a driving wheel (41) arranged on the equipment main body (1), a telescopic wheel group (42) arranged on the equipment main body (1) and capable of being telescopic in the horizontal direction, a first guide wheel group (43) arranged on the equipment main body (1), a second guide wheel group (44) arranged on the welding working device (2), and a lifting mechanism for driving the telescopic wheel group (42) to move in the vertical direction.

3. The automatic welding equipment for inner girth seams of large diameter steel pipes according to claim 2, characterized in that: The first guide wheel set (43) and the second guide wheel set (44) are both distributed in an eight-shaped pattern.

4. The automatic welding equipment for inner girth seams of large diameter steel pipes according to claim 2, characterized in that: The first positioning mechanism (5) comprises a side main support mechanism (51) arranged on the main device (1) and capable of being extended and retracted in the horizontal direction to abut against the inner wall of the steel pipe, and a side auxiliary support mechanism (52) arranged on the main device (1) and capable of being extended and retracted in the horizontal direction to abut against the inner wall of the steel pipe. The side main support mechanism (51) comprises a first supporting oil cylinder (511) capable of being extended and retracted in the horizontal direction and an arc-shaped support block (512) arranged on the free end of the first supporting oil cylinder (511) and adapted to the inner wall of the steel pipe. The side auxiliary support mechanism (52) has the same structure as the side main support mechanism (51).

5. The automatic welding equipment for inner girth seams of large diameter steel pipes according to claim 4, characterized in that: The side main support mechanism (51) is arranged on an end of the device main body (1) away from the telescopic wheel group (42), and the side auxiliary support mechanism (52) is arranged on an end of the device main body (1) close to the telescopic wheel group (42). The support area of ​​the arc-shaped support block (512) on the side main support mechanism (51) is larger than the support area of ​​the arc-shaped support block (512) on the side auxiliary support mechanism (52).

6. The automatic welding equipment for inner girth seams of large diameter steel pipes according to claim 5, characterized in that: The track mechanism (22) includes a circular track (221) arranged on the connecting sleeve (23), a driving rack (222) arranged on the circular track (221), and a mobile trolley (223) arranged on the driving rack (222); the welding robot arm (21) includes a robot arm (211) arranged on the mobile trolley (223), a welding gun (212) and a vision system arranged on the robot arm (211); and a wire feeder (242), a welding wire reel (243), and a gun cleaner are arranged on the side frame (241).

7. The automatic welding equipment for inner girth seams of large diameter steel pipes according to claim 1, characterized in that: The equipment host (1) comprises a host body (11), on which a power supply (12), an electric control box (13), a pump station (14), and a mounting plate (15) for connecting the connecting device (3) are arranged.

8. A method for automatically welding the inner annular seam of a large diameter steel pipe, characterized in that: The automatic welding equipment for the inner girth seam of a large-diameter steel pipe according to claim 6 comprises the following steps: S1. Adjust the installation position of the connecting device (3) and the side frame (241) and the extension length of the second positioning mechanism (6) according to the diameter of the steel pipe to be welded, and adjust the lifting mechanism so that the horizontal extension direction of the telescopic wheel group (42) coincides with the horizontal radial direction of the steel pipe to be welded; S2, retracting the first supporting oil cylinder (511), retracting the telescopic wheel group (42) and the second supporting oil cylinder (62), and hoisting the large-diameter steel pipe inner ring seam automatic welding equipment into the assembled steel pipe to be welded; S3, extending the telescopic wheel group (42) so that the telescopic wheel group (42) is in rolling connection with the inner wall of the steel pipe to be welded, extending the second supporting oil cylinder (62) so that the ball (64) of the balance frame (63) at the bottom end of the annular positioning frame (61) is in rolling connection with the inner wall of the steel pipe to be welded, starting the walking mechanism (4) to drive the automatic welding equipment for the inner annular seam of the large-diameter steel pipe to move to the working location, and ensuring that the distance between the welding robot arm (21) and the weld is within a preset range; S4, extending the first supporting oil cylinder (511) so that the arc-shaped supporting block (512) of the side main supporting mechanism (51) and the arc-shaped supporting block (512) of the side auxiliary supporting mechanism (52) abut against the inner wall of the steel pipe to be welded, and adjusting and fixing the relative position of the equipment main unit (1) and the steel pipe to be welded; S5, extending the second supporting oil cylinder (62) so that the balls (64) on all the balancing frames (63) abut against the inner wall of the steel pipe to be welded, thereby positioning the relative position of the welding working device (2) and the steel pipe to be welded; S6, start the visual system to check the positioning of the track mechanism (22), the welding robot arm (21) and the equipment status of the wire feeder (242), the robot arm (211), and the welding gun (212); S7. Perform pre-welding preparations, including grinding and preheating the circumferential seam; S8, Circumferential seam automated welding and root cleaning; S9, weld post-processing, completing the welding of a circumferential seam; S10, retract the second supporting oil cylinder (62), keep the ball (64) of the balance frame (63) at the bottom end of the annular positioning frame (61) in rolling connection with the inner wall of the steel pipe to be welded, retract the first supporting oil cylinder (511), so that the arc-shaped supporting block (512) of the side main supporting mechanism (51) and the arc-shaped supporting block (512) of the side auxiliary supporting mechanism (52) are out of contact with the inner wall of the steel pipe to be welded; S11. Repeat steps S3 to S10 to weld the next circumferential seam.

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