Large-span bridge steel truss welding device and process

Abstract

The invention relates to the technical field of bridge construction, and discloses a large-span bridge steel truss welding device and process, comprising a shell, a motor I is arranged in the shell, a belt pulley I is fixedly arranged at the output end of the motor I, a belt is connected in the belt pulley I, and one end of the belt is connected with a belt pulley II; a threaded rod is fixedly arranged in the middle of the second belt wheel, and the two ends of the threaded rod are rotationally connected into the shell. Precise positioning and stable fixing of the welding device on the large-span bridge steel truss are achieved through the clamping plates, shaking displacement is prevented to guarantee welding stability, the sliding table can be flexibly adjusted to provide a moving platform for the posture adjusting mechanism, the welding capacity of different positions is enhanced, the welding efficiency is improved by more than 40%, continuous operation of a single weld joint reaches 3 m, and interruption is not needed. The welding precision and quality are improved, and the problems that when a traditional welding device clamps, the posture of a welding gun is difficult to adjust flexibly, and the welding efficiency is low are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of bridge construction, in particular to a welding device and process for a steel truss of a long-span bridge. Background Art

[0002] In the construction of long-span bridges, a crucial infrastructure, steel trusses play a crucial structural support role. The quality of their welding directly impacts the safety, stability, and service life of the entire bridge. As bridge spans continue to increase and their structures become increasingly complex, the requirements for steel truss welding are becoming increasingly stringent.

[0003] However, the actual welding of steel trusses for long-span bridges presents numerous technical challenges that need to be addressed. Traditional welding equipment faces difficulties in both clamping and welding. Regarding clamping, the clamping structure of traditional devices is often simplistic in design, making it difficult to securely and accurately secure steel truss components. Components can easily shift during welding, impacting welding accuracy and quality. Furthermore, the clamping adjustment is not flexible enough to quickly adapt to steel truss components of varying specifications and shapes, making pre-welding preparations cumbersome and time-consuming.

[0004] In welding operations, traditional welding equipment can often only achieve relatively fixed and limited angle and position adjustments, making it difficult to flexibly cope with the complex and changing weld directions on long-span bridge steel trusses. Since the weld shapes of long-span bridge steel trusses are not regular and uniform, there will be bends at various angles, bends of different arcs, and different spatial positions. The welding gun of traditional welding equipment cannot change its posture in real time and accurately according to these complex weld directions. As a result, during welding operations, the welding gun and the weld cannot always maintain the optimal relative position and angle relationship, which can easily lead to unstable weld pool, uneven weld filling, and increased welding defects. Summary of the Invention

[0005] In response to the shortcomings of the existing technology, the present invention provides a large-span bridge steel truss welding device and process, which solves the problems of traditional welding devices that are difficult to flexibly adjust the welding gun posture during clamping and have low welding efficiency.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions: a large-span bridge steel truss welding device, comprising a shell, wherein a motor 1 is provided inside the shell, a pulley 1 is fixedly provided at the output end of the motor 1, a belt is connected to the inside of the pulley 1, one end of the belt is connected to the pulley 2, a threaded rod is fixedly provided in the middle of the pulley 2, both ends of the threaded rod are rotatably connected to the inside of the shell, the middle ends of the threaded rod are threadedly connected to a guide plate, one end of the guide plate is provided with a splint, the top of the splint is provided with a guide block, the outer wall of the guide block is slidably connected to a slide through a slide groove, a plurality of lighting lamps are provided on one side of the slide, the lower surface of the slide is slidably connected to the upper surface of the shell, a control system is provided inside the shell, and the upper surface of the slide is provided with a posture adjustment mechanism.

[0007] Preferably, the posture adjustment mechanism includes an electric push rod, the bottom end of the electric push rod is arranged on the upper surface of the slide, and the output end of the electric push rod is rotatably connected to a rotating shaft 1.

[0008] Preferably, a hinge block 1 is provided at the top of the rotating shaft 1, the middle part of the hinge block 1 is rotatably connected to the hinge block 2 via the rotating shaft 2, a platform is provided at the top of the hinge block 2, and a welding actuator is provided on the upper surface of the posture adjustment mechanism.

[0009] Preferably, the welding actuator includes a six-axis welding arm, the bottom end of the six-axis welding arm is arranged on the upper surface of the platform, and one end of the six-axis welding arm is provided with a double-wire pulse MIG welding gun.

[0010] Preferably, a second motor is provided inside the housing, a first bevel gear is fixedly provided at the output end of the second motor, a tooth end of the first bevel gear is symmetrically meshed with a second bevel gear, and a third rotating shaft is fixedly provided in the middle of the second bevel gear.

[0011] Preferably, both ends of the rotating shaft three pass through the fixed plate two and are provided with a movable magnetic attraction mechanism, a fixed plate one is fixedly provided on one side of the fixed plate two, and the upper surface of the fixed plate one is provided at the bottom end of the shell.

[0012] Preferably, the mobile magnetic attraction mechanism includes a driving wheel, the middle part of the driving wheel is arranged at one end of the rotating shaft three, the outer wall of the driving wheel is provided with a permanent magnetic track through internal teeth, and the outer wall of the permanent magnetic track is provided with a plurality of magnetic blocks.

[0013] Preferably, the inner teeth of the permanent magnetic track are symmetrically connected to the guide wheel, a fixing frame is provided in the middle of the guide wheel, one side of the fixing frame is provided on one side of the second fixing plate, and a plurality of load-bearing wheels are provided on the outer wall of the fixing frame.

[0014] Preferably, the control system includes: The position control module is used to receive multi-source position information from the laser tracking system, the clamping mechanism positioning sensor, and the drive mechanism movement feedback device. After analyzing and processing the information based on preset requirements and algorithms, it generates control instructions and sends them to the relevant execution components to control the welding device and welding gun position. The posture adjustment module is used to rely on the posture information fed back by the laser tracking system and the six-axis welding arm angle sensor, combined with the preset weld posture requirements, to generate control instructions through algorithms and send them to the six-axis welding arm joint motors; The parameter adjustment module is used to collect multiple types of data such as environmental parameters monitored by the laser tracking system and the welding gun's own working parameters, and dynamically adjust the welding parameters using an adaptive algorithm after comparing them with preset standards; Communication management module, used to integrate communication protocols and interfaces, establish and maintain communication links between the control system and various subsystems and external monitoring equipment; The fault diagnosis and early warning module is used to build a fault diagnosis model with the help of big data analysis, monitor the parameters of key parts of the welding device in real time, diagnose faults in a timely manner, issue early warnings, and take protective measures; Human-computer interaction module, used to provide operators with a visual operation interface and input devices, so that they can check the welding system status, adjust parameters and receive prompt information; The laser tracking system module is used to transmit and receive laser beams, calculate and process the position deviation information between the welding gun and the weld, output control instructions, and control the position and posture of the welding gun in real time.

[0015] Preferably, a process for welding a long-span bridge steel truss device, used for said long-span bridge steel truss welding device, comprises the following steps: Step 1: Pre-install guide rings at the locations where the steel trusses are to be welded to provide guidance for subsequent device positioning; Step 2: Positioning the device: Move the welding device to the welding position via the magnetic crawler chassis and use the guide ring for precise positioning; Step 3: Welding gun posture adjustment: The welding gun is adjusted at multiple angles through the three-degree-of-freedom platform of the posture adjustment mechanism to ensure that it is in the best welding position with the weld. Step 4: Double-wire oscillating welding: start the double-wire pulse MIG welding gun of the welding actuator to perform double-wire oscillating welding operation; Step 5: Forced cooling. After welding is completed, the welded parts are forced to cool.

[0016] The present invention provides a long-span bridge steel truss welding device and process. It has the following beneficial effects: 1. In the present invention, the welding device is accurately positioned and stably fixed on the steel truss of a large-span bridge through a clamping plate, preventing shaking and displacement to ensure welding stability. The slide can be flexibly adjusted to provide a mobile platform for the posture adjustment mechanism, enhancing the welding capacity at different positions, improving welding efficiency by more than 40%, and allowing single-pass welding to operate continuously for up to 3 meters without interruption, thereby improving welding accuracy and quality and solving the problems of difficult flexible adjustment of the welding gun posture during clamping and low welding efficiency in traditional welding devices.

[0017] 2. In the present invention, multi-degree-of-freedom posture adjustment is achieved through the posture adjustment mechanism, and the six-axis welding arm in the welding actuator is precisely positioned, and the advanced technology of the double-wire pulse MIG welding gun is applied, which comprehensively improves the accuracy, efficiency and quality of welding, enables the welding device to better adapt to complex welding scenes, and solves the problems of single welding gun posture, difficulty in flexibly responding to complex welds, and insufficient welding position accuracy in traditional welding devices.

[0018] 3. In the present invention, the mobile magnetic attraction mechanism achieves good effects of stable adsorption movement, precise guidance and smooth load-bearing through the coordinated cooperation of various components. Its own weight is controlled at ≤80kg, which effectively reduces the load-bearing requirements of high-altitude operations and provides a solid guarantee for the accurate movement of welding equipment on the steel trusses of large-span bridges and the smooth progress of welding operations. It successfully solves the problems of traditional welding equipment being easy to fall off and inaccurate movement trajectory in this scenario, and improves the reliability of the overall welding operation.

[0019] 4. In the present invention, by controlling the functions of each module of the control system and the dual-wire energy distribution and swing control measures, the accuracy, quality, efficiency and overall reliability of the welding operation are significantly improved. While reducing the welding deformation to ≤2mm / m, key problems affecting the welding effect such as inaccurate positioning and inaccurate relative position between the welding gun and the weld are solved, thereby optimizing the welding operation effect.

[0020] 5. The present invention achieves precise guidance and positioning of the welding device through the coordinated operation of various steps in the welding process for long-span bridge steel trusses. The welding gun's posture can be flexibly adjusted according to the weld seam conditions, ensuring efficient and high-quality welding. It also allows for timely cooling of the welded area. This results in a welding pass rate of ≥99.5% for all positions and a joint tensile strength of ≥690 MPa. This effectively improves welding accuracy, efficiency, quality, and joint stability, resolving the issues of welding guns' difficulty adapting to complex welds, resulting in poor welding efficiency and quality when welding long-span bridge steel trusses. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a front perspective diagram of a long-span bridge steel truss welding device proposed by the present invention; Figure 2This is a schematic diagram of the partial structure of the outer shell of a large-span bridge steel truss welding device proposed by the present invention; Figure 3 This is a schematic diagram of the local structure of the welding machine of a long-span bridge steel truss welding device proposed by the present invention; Figure 4 This is a schematic diagram of the partial structure of the six-axis welding arm of a long-span bridge steel truss welding device proposed by the present invention; Figure 5 This is a schematic diagram of the partial structure of the platform of a long-span bridge steel truss welding device proposed by the present invention; Figure 6 This is a partial structural diagram of a motor of a large-span bridge steel truss welding device proposed by the present invention; Figure 7 This is a schematic diagram of the partial structure of the motor of a large-span bridge steel truss welding device proposed by the present invention; Figure 8 This is a partial structural diagram of the permanent magnetic track of a long-span bridge steel truss welding device proposed by the present invention; Figure 9 This is a schematic diagram of a control system module for a long-span bridge steel truss welding device proposed by the present invention; Figure 10 This is a process flow chart of a large-span bridge steel truss welding device proposed by the present invention.

[0022] Among them, 1. Shell; 2. Welding machine; 3. Six-axis welding arm; 4. Double-wire pulse MIG welding gun; 5. Platform; 6. Electric push rod; 7. Slide; 8. Lighting lamp; 9. Clamp; 10. Permanent magnet track; 11. Camera; 12. Radar; 13. Guide plate; 14. Rotating shaft one; 15. Articulated block one; 16. Articulated block two; 17. Rotating shaft two; 18. Guide block; 19. Slide; 20. Motor one; 21. Pulley one; 22. Belt; 23. Pulley two; 24. Threaded rod; 25. Motor two; 26. Bevel gear one; 27. Rotating shaft three; 28. Bevel gear two; 29. ​​Fixed plate one; 30. Magnetic block; 31. Fixed plate two; 32. Driving wheel; 33. Fixed frame; 34. Load-bearing wheel; 35. Guide wheel. DETAILED DESCRIPTION

[0023] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0024] Please see the attached Figure 1 -Attached Figure 3 , Attachment Figure 6 An embodiment of the present invention provides a long-span bridge steel truss welding device, including a shell 1, a motor 20 is provided inside the shell 1, a pulley 21 is fixedly provided at the output end of the motor 20, a belt 22 is connected to the inside of the pulley 21, one end of the belt 22 is connected to a pulley 23, a threaded rod 24 is fixedly provided in the middle of the pulley 23, both ends of the threaded rod 24 are rotatably connected to the inside of the shell 1, the middle ends of the threaded rod 24 are threadedly connected to a guide plate 13, one end of the guide plate 13 is provided with a splint 9, the top of the splint 9 is provided with a guide block 18, the outer wall of the guide block 18 is slidably connected to a slide 7 through a slide groove 19, a plurality of lighting lamps 8 are provided on one side of the slide 7, the lower surface of the slide 7 is slidably connected to the upper surface of the shell 1, a control system is provided inside the shell 1, and the upper surface of the slide 7 is provided with a posture adjustment mechanism.

[0025] Specifically, after motor 1 (20) is started, it generates rotational power, which is transmitted through its output end to pulley 1 (21), causing pulley 1 (21) to begin rotating. Due to friction between pulley 1 (21) and belt 22, belt 22 also begins to move under the influence of pulley 1 (21). The other end of belt 22 is connected to pulley 2 (23), and the movement of belt 22 in turn drives pulley 2 (23) to rotate.

[0026] The threaded rod 24 fixedly mounted in the middle of the second pulley 23 rotates synchronously with the rotation of the second pulley 23. Because both ends of the threaded rod 24 are rotatably connected to the interior of the housing 1, and both ends of the middle portion of the threaded rod 24 are connected to the guide plate 13 via threads, according to the principle of threaded transmission, when the threaded rod 24 rotates, the guide plate 13 moves along the axial direction of the threaded rod 24.

[0027] A clamping plate 9 is attached to one end of the guide plate 13. When the guide plate 13 moves, driven by the threaded rod 24, the clamping plate 9 moves with it. The clamping plate 9 can be used to clamp and secure portions of the steel truss structure of long-span bridges. After the welding device moves to the welding position, the threaded rod 24 is rotated by controlling the motor 20, driving the guide plate 13 and the clamping plate 9 to move. This clamping plate 9 is then clamped to the appropriate position on the steel truss, acting as a stabilizing device.

[0028] A guide block 18 is mounted on the top of the clamping plate 9. The outer wall of the guide block 18 engages with a slot 19 on the slide 7, forming a sliding connection. When the guide plate 13 and clamping plate 9 move, the guide block 18 slides within the slot 19, thereby driving the slide 7 along the upper surface of the housing 1. The sliding direction of the slide 7 is correlated with the direction of movement of the guide plate 13. Because the slot 19 restricts the guide block 18, the slide 7 exhibits excellent stability and guidance.

[0029] Several lights 8 are installed on one side of the slide 7. These lights 8 are primarily used to illuminate the welding process. In welding large-span bridge steel trusses, due to their complex structure, some welding areas may be poorly lit, affecting welding quality and the operator's vision. Lights 8 illuminate the welding area, allowing the operator to clearly observe the welding process, such as weld alignment and the state of the weld pool, thereby improving welding control.

[0030] The clamping plate 9 is used to achieve precise positioning and stable fixation of the welding device on the steel truss of a long-span bridge. The clamping effect of the clamping plate 9 can effectively prevent the welding device from shaking or shifting during the welding process, ensuring the stability of the welding operation. The slide 7 can flexibly adjust its position, providing a movable platform for the posture adjustment mechanism, further enhancing the ability of the welding device to perform welding operations in different positions, and can provide different welding angles and welding positions. The welding efficiency is increased by more than 40%, and the continuous operation length of a single weld can reach 3m without interruption, thereby improving the accuracy and quality of welding. It solves the problem that traditional welding devices are difficult to flexibly adjust the welding gun posture during clamping and have low welding efficiency.

[0031] Please see the attached Figure 1 -Attached Figure 5 The posture adjustment mechanism includes an electric push rod 6, the bottom end of the electric push rod 6 is arranged on the upper surface of the slide 7, the output end of the electric push rod 6 is rotatably connected to a rotating shaft 14, the top of the rotating shaft 14 is provided with a hinge block 15, the middle part of the hinge block 15 is rotatably connected to a hinge block 2 16 through a rotating shaft 2 17, the top of the hinge block 2 16 is provided with a platform 5, and the upper surface of the posture adjustment mechanism is provided with a welding actuator; the welding actuator includes a six-axis welding arm 3, the bottom end of the six-axis welding arm 3 is arranged on the upper surface of the platform 5, and one end of the six-axis welding arm 3 is provided with a double-wire pulse MIG welding gun 4.

[0032] Specifically, the electric push rod 6 serves as the power source for the posture adjustment mechanism, with its bottom end fixed to the upper surface of the slide 7. When the electric push rod 6 receives a control signal from the control system, it telescopes, thereby driving the rotation shaft 14, to which it is rotatably connected, to move. A hinge block 15 is provided at the top of the rotation shaft 14. When the electric push rod 6 telescopes, it pulls the rotation shaft 14 to change position, thereby causing the hinge block 15 to move accordingly. The middle portion of the hinge block 15 is rotationally connected to the hinge block 2 16 via the rotation shaft 2 17. This allows relative rotation around the rotation shaft 2 17 during the movement of the hinge block 15. Due to the presence of the rotation shaft 2 17, the relative angle between the hinge block 15 and the hinge block 2 16 can change within a certain range, just like a movable joint, achieving angle changes within a two-dimensional plane. In addition, a platform 5 is provided at the top of the hinge block 2 16. Through the extension and retraction of the electric push rod 6 and the rotation coordination of the rotating shaft 14 and the rotating shaft 2 17, the platform 5 can achieve up and down, left and right and a certain angle of tilt, thereby achieving the effect of adjusting the position and posture in multiple degrees of freedom.

[0033] It should be noted that when adjusting the tilt angle of the platform 5, if one of the electric push rods 6 extends, the other two electric push rods 6 will correspondingly retract; similarly, if one of the electric push rods 6 retracts, the other two electric push rods 6 will correspondingly extend. In addition, before adjusting the tilt angle of the platform 5, it is necessary to adjust the platform 5 to a horizontal state.

[0034] The six-axis welding arm 3, with its bottom end positioned on the upper surface of the platform 5, consists of six independently rotatable articulated axes. Each articulated axis is equipped with a corresponding motor, reducer, and transmission components (such as gears and chains). When the control system sends control instructions to the motor of each articulated axis, the motor drives the reducer, which in turn rotates the articulated axis via the transmission components. For example, the rotation of the first articulated axis can cause the welding arm to swing up and down vertically, while the rotation of the second articulated axis can control the welding arm's left and right horizontal movement. Subsequent articulated axes work in tandem, enabling the distal end of the welding arm (i.e., the end where the twin-wire pulsed MIG welding torch 4 is mounted) to achieve extremely complex motion trajectories in space, allowing precise positioning at different weld locations and angles for welding operations.

[0035] The twin-wire pulsed MIG welding gun 4 uses two welding wires for simultaneous welding. Each wire has an independent wire feeding system, and the wire feed motor delivers the wires to the weld pool at a constant speed according to the set wire feed speed. During the welding process, the welding power supply outputs a pulsed current that periodically switches between high and low currents. During the high-current phase, the welding wires rapidly melt, forming molten droplets that transfer into the weld pool, achieving efficient metal filling. During the low-current phase, the weld pool is stabilized to a certain extent, preventing excessive fluctuations. Furthermore, the pulse current parameters of the two welding wires (such as pulse frequency, peak current, and base current) can be adjusted individually according to the welding process requirements. By properly allocating the energy between the two welding wires, the welding heat input can be better controlled, achieving optimized weld quality.

[0036] The posture adjustment mechanism achieves multi-degree-of-freedom posture adjustment through the coordination of components such as the electric push rod, rotating shaft, and hinge block, providing flexible posture adaptation for the welding actuator, allowing the welding gun to accurately match complex welds. The six-axis welding arm in the welding actuator can accurately position the welding gun. The twin-wire pulse MIG welding gun uses twin-wire and pulsed current technology to improve welding efficiency, ensure quality, and control deformation, thereby improving overall welding accuracy, efficiency, and quality, and enhancing adaptability to complex welding scenarios. This solves the problems of traditional welding devices with single welding gun posture and insufficient welding position accuracy.

[0037] Please see the attached Figure 3 , Attachment Figure 7 A motor 25 is provided inside the housing 1. A bevel gear 1 26 is fixedly provided at the output end of the motor 25. The tooth ends of the bevel gear 1 26 are symmetrically meshed with the bevel gear 2 28. A rotating shaft 3 27 is fixedly provided in the middle of the bevel gear 2 28. Both ends of the rotating shaft 3 27 pass through the fixed plate 2 31 and are provided with a movable magnetic attraction mechanism. A fixed plate 1 29 is fixedly provided on one side of the fixed plate 2 31. The upper surface of the fixed plate 1 29 is provided at the bottom end of the housing 1.

[0038] Specifically, Motor 2 (25) serves as the power source. When powered on, the output shaft of Motor 2 (25) begins to rotate. Since Bevel Gear 1 (26) is fixed to the output end of Motor 2 (25), Bevel Gear 1 (26) rotates synchronously with the output shaft of Motor 2 (25). Bevel Gear 1 (26) is symmetrically meshed with Bevel Gear 2 (28). According to the principle of bevel gear transmission, the rotational motion and power of Bevel Gear 1 (26) are transmitted to Bevel Gear 2 (28) through the meshing action between the teeth, causing Bevel Gear 2 (28) to rotate about its own central axis.

[0039] A rotating shaft 3 27 is fixedly mounted in the middle of bevel gear 2 28 . The rotation of bevel gear 2 28 drives the rotating shaft 3 27 to rotate synchronously. Both ends of rotating shaft 3 27 pass through fixed plate 2 31 and are connected to a movable magnetic mechanism. As rotating shaft 3 27 rotates, it provides rotational power to the movable magnetic mechanism, driving its associated components, thereby enabling the entire welding device to move across the surface of a long-span bridge steel truss.

[0040] Fixed plate 1 29 is fixed to one side of fixed plate 2 31 , with its upper surface positioned at the bottom end of housing 1 . These two fixed plates provide both fixing and support. They securely support components such as rotating shaft 3 27 and the movable magnetic mechanism, ensuring their stable position during operation and preventing loosening or displacement. They also provide reliable support for the bottom structure of the entire welding device, ensuring its overall stability during movement and operation on the steel truss.

[0041] Through the coordination of motor 25, bevel gear drive, rotating shaft 3 27, and a movable magnetic mechanism, as well as the stable support of fixing plate 1 29 and fixing plate 2 31, the welding device achieves stable movement and reliable support on long-span bridge steel trusses. It also assists in precise positioning, laying the foundation for smooth welding operations and improving welding quality and efficiency. This solves the problems of unstable movement and unreliable support of traditional welding devices when operating on long-span bridge steel trusses.

[0042] Please see the attached Figure 1 -Attached Figure 3 , Attachment Figure 7 -Attached Figure 8 The mobile magnetic attraction mechanism includes a driving wheel 32, the middle part of the driving wheel 32 is set at one end of the rotating shaft three 27, the outer wall of the driving wheel 32 is provided with a permanent magnetic track 10 through the inner teeth, the outer wall of the permanent magnetic track 10 is provided with a plurality of magnetic blocks 30, the inner teeth of the permanent magnetic track 10 are symmetrically connected with a guide wheel 35, the middle part of the guide wheel 35 is provided with a fixing frame 33, one side of the fixing frame 33 is provided on one side of the fixing plate two 31, and the outer wall of the fixing frame 33 is provided with a plurality of load-bearing wheels 34.

[0043] Specifically, the middle portion of the driving wheel 32 is mounted at one end of the rotating shaft 3 27. When the rotating shaft 3 27 begins to rotate under the drive of the motor 2 25 via the bevel gear transmission, the driving wheel 32 rotates synchronously with the rotating shaft 3 27. Because the outer wall of the driving wheel 32 is connected to the permanent magnetic track 10 via internal teeth, the rotation of the driving wheel 32, through the meshing action between the internal teeth and the internal teeth of the permanent magnetic track 10, drives the permanent magnetic track 10 to circulate around the driving wheel 32 and related mating components.

[0044] The outer wall of the permanent magnetic track 10 is provided with a number of magnetic blocks 30, which are typically made of a permanent magnetic material with strong magnetism. In the welding scenario of steel trusses on long-span bridges, the steel trusses are generally made of steel. When the permanent magnetic track 10 moves to a position where it contacts the surface of the steel truss, the magnetic blocks 30 generate an adsorption force with the steel truss due to their inherent magnetism. This adsorption force allows the welding device to fit tightly to the surface of the steel truss, ensuring that the device does not easily detach from the steel truss during movement. It also enhances the stability of the device during welding operations to a certain extent, preventing the device from shifting due to external factors (such as slight vibrations, wind, etc.).

[0045] The inner teeth of permanent magnetic crawler 10 are symmetrically connected with guide wheel 35, and the middle part of guide wheel 35 is arranged on fixed frame 33, and one side of fixed frame 33 is installed on one side of fixed plate 2 31. Guide wheel 35 plays the guiding and supporting role to permanent magnetic crawler 10. When permanent magnetic crawler 10 moves under the driving of driving wheel 32, guide wheel 35 can roll along the inner teeth of permanent magnetic crawler 10, ensure that permanent magnetic crawler 10 runs according to predetermined track, prevents it from running off track, derailment and other situations. Fixed frame 33 provides a stable installation base for guide wheel 35, so that it can play a role stably. Simultaneously, the outer wall of fixed frame 33 is provided with some load-bearing wheels 34, which mainly bear part of the weight of welding device. By contacting and rolling with steel truss surface, the gravity of device is further shared, the friction between permanent magnetic crawler 10 and steel truss is reduced, the device is smoother when moving, and can better adapt to the uneven situation that may exist on steel truss surface, guarantee the stability of whole moving process.

[0046] The mobile magnetic mechanism achieves stable adsorption movement, precise guidance, and smooth load-bearing through the synergistic effects of active wheels driving the permanent magnetic tracks, magnetic blocks attracting the steel trusses, guide wheels providing precise guidance, and load-bearing wheels steadily bearing the load. The device weighs ≤80kg, reducing the load requirements for aerial work and providing a strong guarantee for the accurate movement and smooth welding operations of the welding device on long-span bridge steel trusses. This solves the problem of traditional welding devices easily falling off and having inaccurate movement trajectory when moving on long-span bridge steel trusses.

[0047] Please see the attached Figure 9 , the control system includes: The position control module is used to receive multi-source position information from the laser tracking system, the clamping mechanism positioning sensor, and the drive mechanism movement feedback device. After analyzing and processing the information based on preset requirements and algorithms, it generates control instructions and sends them to the relevant execution components to control the welding device and welding gun position. The posture adjustment module is used to rely on the posture information fed back by the laser tracking system and the six-axis welding arm angle sensor, combined with the preset weld posture requirements, to generate control instructions through algorithms and send them to the six-axis welding arm joint motors; The parameter adjustment module is used to collect multiple types of data such as environmental parameters monitored by the laser tracking system and the welding gun's own working parameters, and dynamically adjust the welding parameters using an adaptive algorithm after comparing them with preset standards; Communication management module, used to integrate communication protocols and interfaces, establish and maintain communication links between the control system and various subsystems and external monitoring equipment; The fault diagnosis and early warning module is used to build a fault diagnosis model with the help of big data analysis, monitor the parameters of key parts of the welding device in real time, diagnose faults in a timely manner, issue early warnings, and take protective measures; Human-computer interaction module, used to provide operators with a visual operation interface and input devices, so that they can check the welding system status, adjust parameters and receive prompt information; The laser tracking system module is used to transmit and receive laser beams, calculate and process the position deviation information between the welding gun and the weld, output control instructions, and control the position and posture of the welding gun in real time.

[0048] Specifically, the various modules of the control system work together. The position control module integrates multi-source position information and processes it through algorithms to issue instructions to control the welding device and welding gun position; the posture adjustment module uses algorithms to generate instructions to adjust the six-axis welding arm joint motor to change the welding gun posture based on laser tracking and angle sensor feedback; the parameter adjustment module collects multiple types of data and compares them with preset standards, and then uses adaptive algorithms to dynamically adjust welding parameters; the communication management module integrates communication protocols and builds communication links to ensure information interaction; the fault diagnosis and early warning module uses big data analysis to build models, monitor key parameters, diagnose faults, issue early warnings and take protective measures; the human-computer interaction module realizes information interaction and operation control between operators and systems through visual interfaces and input devices; the laser tracking system module transmits and receives laser beams, calculates deviation information based on optical principles, and issues instructions to control the welding gun position and posture in real time.

[0049] Position control ensures accurate welding position, posture adjustment ensures a reasonable welding gun posture, parameter adjustment maintains stable welding quality, communication management achieves efficient and stable communication, fault diagnosis and early warning ensure safe equipment operation, human-machine interaction facilitates operational control and information acquisition, and the laser tracking system improves welding precision. Through dual-wire energy distribution and swing control, welding deformation is reduced to ≤2mm / m, improving the accuracy, quality, efficiency, and overall reliability of welding operations. This solves the problem of inaccurate positioning and inaccurate relative position between the welding gun and the weld caused by position control.

[0050] Please see the attached Figure 10 A process for welding a long-span bridge steel truss device, for use in a long-span bridge steel truss welding device, comprises the following steps: Step 1: Pre-install guide rings at the locations where the steel trusses are to be welded to provide guidance for subsequent device positioning; Step 2: Positioning the device: Move the welding device to the welding position via the magnetic crawler chassis and use the guide ring for precise positioning; Step 3: Welding gun posture adjustment: The welding gun is adjusted at multiple angles through the three-degree-of-freedom platform of the posture adjustment mechanism to ensure that it is in the best welding position with the weld. Step 4: Double-wire oscillating welding, start the double-wire pulse MIG welding gun 4 of the welding actuator to perform double-wire oscillating welding operation; Step 5: Forced cooling. After welding is completed, the welded parts are forced to cool.

[0051] Specifically, based on the size and shape of the steel truss to be welded, a guide ring of appropriate specifications is selected and securely installed in the corresponding position using professional installation tools and processes. The inner diameter of the guide ring closely matches the outer diameter of the steel truss to be welded. Its specific structure and shape can provide physical contact and guidance for the corresponding positioning components on the device when the subsequent welding device approaches, allowing the welding device to make preliminary positioning judgments based on the position and direction of the guide ring.

[0052] The welding device relies on a magnetic crawler chassis. Its internal magnetic structure generates a strong suction force through electromagnetic induction, firmly adhering to the surface of the steel truss and ensuring stable attachment. The drive mechanism activates the crawler tracks of the magnetic crawler chassis, driving the entire device along the steel truss. When it approaches the pre-installed guide ring, the positioning components on the device engage with the guide ring. Through mechanical limiters and sensor detection, precise position information is obtained. This information is compared with the preset standard position parameters, and the device's position is adjusted to achieve precise positioning at the welding point.

[0053] The three-degree-of-freedom platform in the posture adjustment mechanism achieves motion control in each degree of freedom direction through motor drive and mechanical transmission. Its internal angle sensors, displacement sensors, and other sensors monitor the platform's current posture angle and position information in real time and provide feedback to the control system. Based on the preset weld position requirements and the position deviation data between the welding gun and the weld fed back by the laser tracking system, the control system calculates the angle and displacement that need to be adjusted. It then sends control instructions to the three-degree-of-freedom platform's motor, driving the platform to rotate and translate the welding gun accordingly to achieve the optimal welding position with the weld, such as aligning the welding gun's central axis with the weld's centerline and ensuring that the welding gun's angle meets the welding process requirements.

[0054] After the twin-wire pulsed MIG welding gun 4 of the welding actuator is activated, the welder supplies a stable pulse current to the twin wires. The arc heat rapidly melts the two wires, forming molten droplets that transfer to the weld area. Simultaneously, the welding control system sets twin-wire oscillation parameters, such as oscillation frequency and amplitude. This drives the welding gun's oscillation mechanism to periodically oscillate left and right according to these parameters, ensuring that the molten wires evenly cover the weld area. Furthermore, the twin-wire pulse current can be adaptively adjusted based on real-time feedback from the welding process (such as the weld pool state and weld temperature), ensuring stable and uniform heat input during the welding process.

[0055] After welding is completed, the forced cooling system is immediately activated. The appropriate cooling method (such as air cooling, water cooling, or gas-liquid mixed cooling) is selected based on factors such as the material and thickness of the weld area and the welding process parameters. With air cooling, a powerful fan blows cold air into the weld area to remove heat. With water cooling, cooling water circulates through specific cooling pipes to absorb heat from the weld area. Gas-liquid mixed cooling combines the advantages of both methods, spraying the cooling medium onto the weld area at a set flow rate and velocity to accelerate heat dissipation. Simultaneously, a temperature sensor monitors the temperature changes of the weld area in real time. Cooling stops when the temperature drops to a safe range that meets process requirements.

[0056] The process of this large-span bridge steel truss welding device achieves precise positioning guidance for the welding device, flexible adjustment of the welding gun posture, efficient and high-quality welding, and timely and effective cooling of the welded parts through the orderly coordination of various steps. The qualified rate of all-position welding is ≥99.5%, and the tensile strength of the joint is ≥690MPa. This improves the accuracy, efficiency, quality, and stability of the welding joints. This solves the problem of the welding gun's difficulty in adapting to complex welds, resulting in poor welding efficiency and quality in the welding of large-span bridge steel trusses.

[0057] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A long-span bridge steel truss welding device, comprising a housing (1), characterized in that: The housing (1) is provided with a motor (20) inside, a pulley (21) is fixedly provided at the output end of the motor (20), a belt (22) is connected to the inside of the pulley (21), one end of the belt (22) is connected to a pulley (23), a threaded rod (24) is fixedly provided in the middle of the pulley (23), both ends of the threaded rod (24) are rotatably connected to the inside of the housing (1), both ends of the middle of the threaded rod (24) are threadedly connected to a guide plate (13), one end of the guide plate (13) is provided with a clamping plate (9), the top of the clamping plate (9) is provided with a guide block (18), the outer wall of the guide block (18) is slidably connected to a slide (7) through a slide groove (19), a plurality of lighting lamps (8) are provided on one side of the slide (7), the lower surface of the slide (7) is slidably connected to the upper surface of the housing (1), a control system is provided inside the housing (1), and the upper surface of the slide (7) is provided with a posture adjustment mechanism.

2. A long-span bridge steel truss welding device according to claim 1, characterized in that: The posture adjustment mechanism comprises an electric push rod (6), the bottom end of the electric push rod (6) is arranged on the upper surface of the slide (7), and the output end of the electric push rod (6) is rotatably connected to a rotating shaft 1 (14).

3. A long-span bridge steel truss welding device according to claim 2, characterized in that: The top of the rotating shaft 1 (14) is provided with an articulated block 1 (15), the middle portion of the articulated block 1 (15) is rotatably connected to the articulated block 2 (16) via the rotating shaft 2 (17), the top of the articulated block 2 (16) is provided with a platform (5), and the upper surface of the posture adjustment mechanism is provided with a welding actuator.

4. A long-span bridge steel truss welding device according to claim 3, characterized in that: The welding actuator comprises a six-axis welding arm (3), the bottom end of the six-axis welding arm (3) is arranged on the upper surface of the platform (5), and one end of the six-axis welding arm (3) is provided with a double-wire pulse MIG welding gun (4).

5. The long-span bridge steel truss welding device according to claim 1, characterized in that: A second motor (25) is provided inside the housing (1), a bevel gear (26) is fixedly provided at the output end of the second motor (25), a tooth end of the first bevel gear (26) is symmetrically meshed with a second bevel gear (28), and a rotating shaft (27) is fixedly provided at the middle of the second bevel gear (28).

6. A long-span bridge steel truss welding device according to claim 5, characterized in that: Both ends of the rotating shaft 3 (27) pass through the fixed plate 2 (31) and are provided with a movable magnetic attraction mechanism. A fixed plate 1 (29) is fixedly provided on one side of the fixed plate 2 (31), and the upper surface of the fixed plate 1 (29) is provided at the bottom end of the housing (1).

7. A long-span bridge steel truss welding device according to claim 6, characterized in that: The mobile magnetic attraction mechanism includes a driving wheel (32), the middle portion of the driving wheel (32) is arranged at one end of the rotating shaft three (27), the outer wall of the driving wheel (32) is provided with a permanent magnetic track (10) through internal teeth, and the outer wall of the permanent magnetic track (10) is provided with a plurality of magnetic attraction blocks (30).

8. A long-span bridge steel truss welding device according to claim 7, characterized in that: The inner teeth of the permanent magnetic crawler (10) are symmetrically connected to a guide wheel (35), a fixing frame (33) is provided in the middle of the guide wheel (35), one side of the fixing frame (33) is provided on one side of the second fixing plate (31), and a plurality of load-bearing wheels (34) are provided on the outer wall of the fixing frame (33).

9. The long-span bridge steel truss welding device according to claim 1, characterized in that: The control system includes: The position control module is used to receive multi-source position information from the laser tracking system, the clamping mechanism positioning sensor, and the drive mechanism movement feedback device. After analyzing and processing the information based on preset requirements and algorithms, it generates control instructions and sends them to the relevant execution components to control the welding device and welding gun position. The posture adjustment module is used to rely on the posture information fed back by the laser tracking system and the six-axis welding arm angle sensor, combined with the preset weld posture requirements, to generate control instructions through algorithms and send them to the six-axis welding arm joint motors; The parameter adjustment module is used to collect multiple types of data such as environmental parameters monitored by the laser tracking system and the welding gun's own working parameters, and dynamically adjust the welding parameters using an adaptive algorithm after comparing them with preset standards; Communication management module, used to integrate communication protocols and interfaces, establish and maintain communication links between the control system and various subsystems and external monitoring equipment; The fault diagnosis and early warning module is used to build a fault diagnosis model with the help of big data analysis, monitor the parameters of key parts of the welding device in real time, diagnose faults in a timely manner, issue early warnings, and take protective measures; Human-computer interaction module, used to provide operators with a visual operation interface and input devices, so that they can check the welding system status, adjust parameters and receive prompt information; The laser tracking system module is used to transmit and receive laser beams, calculate and process the position deviation information between the welding gun and the weld, output control instructions, and control the position and posture of the welding gun in real time.

10. A process for welding a long-span bridge steel truss device, characterized in that: A long-span bridge steel truss welding device according to any one of claims 1 to 9 comprises the following steps: Step 1: Pre-install guide rings at the locations where the steel trusses are to be welded to provide guidance for subsequent device positioning; Step 2: Positioning the device: Move the welding device to the welding position via the magnetic crawler chassis and use the guide ring for precise positioning; Step 3: Welding gun posture adjustment: The welding gun is adjusted at multiple angles through the three-degree-of-freedom platform of the posture adjustment mechanism to ensure that it is in the best welding position with the weld. Step 4: Double-wire oscillating welding, start the double-wire pulse MIG welding gun (4) of the welding actuator to perform double-wire oscillating welding operation; Step 5: Forced cooling. After welding is completed, the welded parts are forced to cool.

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