A laser welding robot for reinforcing a steel structure by welding

Abstract

The application relates to the technical field of laser welding, in particular to a laser welding robot for steel structure welding and reinforcement, which comprises a multi-axis mechanical arm, an adaptive jet angle fine adjustment mechanism, an adaptive jet port mechanism and a sealing connection mechanism, a flange connecting disc is bolt-connected and installed at the end of the multi-axis mechanical arm, a protective gas metal jet pipe is arranged on the lower side of the flange connecting disc, the adaptive jet angle fine adjustment mechanism comprises a driven hydraulic cylinder and a lateral communication pipe, a driven telescopic rod is slidably installed on the inner side of the driven hydraulic cylinder, a driving hydraulic cylinder is arranged at the central position in the lateral communication pipe, a power input telescopic rod is slidably installed on the inner side of the driving hydraulic cylinder, and a sealing piston disc is fixedly installed at the end of the power input telescopic rod. The adaptive jet angle fine adjustment mechanism is arranged, the jet direction of the jet pipe is adaptively adjusted by utilizing the Bernoulli principle, an external sensor or a servo motor is not needed, the response is rapid, and the adaptive jet angle fine adjustment mechanism is not influenced by the on-site harsh environment.

Description

Technical Field

[0001] This invention relates to the field of laser welding technology, and in particular to a laser welding robot for welding and reinforcing steel structures. Background Technology

[0002] Laser welding robots, with their advantages of high energy density, low heat input, and ease of automation, have been increasingly applied to on-site reinforcement and repair operations in fields such as steel structure bridges, high-rise buildings, and offshore platforms. In these applications, to ensure welding quality, it is typically necessary to supply a shielding gas (such as argon or a mixture) to the weld pool area to suppress the plasma shielding effect and prevent oxidation of the high-temperature weld pool. Currently, the shielding gas nozzles on the welding heads of existing laser welding robots are mostly fixed (usually between 30° and 45°), and this angle cannot be adjusted during the welding process.

[0003] However, the aforementioned fixed nozzle structure faces the following problems in actual steel structure reinforcement welding: When performing thick plate root pass or deep penetration welding, the laser power is high, and the amount of metal vapor generated increases dramatically. If the fixed nozzle angle cannot effectively disperse the vapor cloud from above the keyhole, the plasma shielding effect is aggravated, easily leading to increased spatter, weld surface oxidation, and decreased energy utilization. When performing thin plate cover pass or end pass welding, the laser power is reduced. If the fixed tilt angle is too large, the airflow easily impacts the surface of the molten pool, causing the molten metal to be blown away, forming defects such as weld depressions or undercut. In addition, although existing technologies have developed solutions that monitor the welding status through sensors and drive the actuator to adjust process parameters, these typically rely on external sensors (such as photoelectric sensors and vision sensors) and servo drive systems, resulting in complex structures and high costs. Furthermore, the dust, vibration, and heat radiation environment commonly present at steel structure reinforcement sites can easily cause interference or damage to electronic sensing elements, making it difficult to guarantee the long-term reliability of the system.

[0004] To address the aforementioned issues, we propose a laser welding robot for steel structure welding reinforcement. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by proposing a laser welding robot for steel structure welding reinforcement.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A laser welding robot for steel structure welding reinforcement includes a multi-axis robotic arm, an adaptive spray angle fine-tuning mechanism, an adaptive spray nozzle mechanism, and a sealing connection mechanism. A flange connecting plate is bolted to the end of the multi-axis robotic arm, and a protective gas metal spray pipe is disposed on the lower side of the flange connecting plate. The adaptive spray angle fine-tuning mechanism includes a driven hydraulic cylinder and a lateral connecting pipe. A driven telescopic rod is slidably mounted inside the driven hydraulic cylinder. A driving hydraulic cylinder is disposed at the center of the lateral connecting pipe, and a power input telescopic rod is slidably mounted inside the driving hydraulic cylinder. A sealing piston plate is fixedly mounted at the end of the power input telescopic rod, and the sealing piston plate slides in contact with the inner wall of the lateral connecting pipe. The tilt adjustment angle range of the protective gas metal spray pipe is ±5°.

[0008] In this invention, the adaptive injection port mechanism includes several sets of lateral sliding cylinders and flap rotating plates. The several sets of lateral sliding cylinders are circumferentially and fixedly installed on the side wall at the port of the protective gas metal injection pipe. The lateral sliding cylinders are connected to the inner side of the protective gas metal injection pipe. A piston slide plate is slidably installed on the inner wall of the lateral sliding cylinder. A steel wire cable is fixedly connected between the piston slide plate and the flap rotating plate.

[0009] In this invention, the sealing connection mechanism includes a gas supply hose, both ends of which are fixedly connected to a mating screw joint. A sealing ring is provided inside the mating screw joint, and the sealing ring is filled with porous elastic rubber particles.

[0010] In this invention, a first oil pipe is fixedly connected to the bottom of the driven hydraulic cylinder, and a second oil pipe is fixedly connected to the bottom of the driving hydraulic cylinder. A hydraulic hose is connected between the first oil pipe and the second oil pipe.

[0011] In this invention, a terminal block, a laser welding head, and a structural folding seat are fixedly installed on the lower side of the flange connecting plate. A stiffening rib is provided at the corner of the structural folding seat. A rotating shaft seat is fixedly installed on the side wall of the structural folding seat. The protective gas metal injection pipe is rotatably installed on the rotating shaft seat. A dustproof venting cap is fastened to the end of the lateral connecting pipe. A ball seat is fixedly installed at the end of the driven telescopic rod. The ball seat is fixedly installed on the side wall of the structural folding seat.

[0012] In this invention, the ratio of the inner diameter of the driving hydraulic cylinder to the inner diameter of the driven hydraulic cylinder is 1:4, a connecting seat is fixedly installed on the outer wall of the protective gas metal injection pipe, and the driven hydraulic cylinder is rotatably installed inside the connecting seat.

[0013] In this invention, the lateral connecting pipe is internally connected to the protective gas metal injection pipe, and the inner wall of the lateral connecting pipe is fixedly connected to the outer wall of the driving hydraulic cylinder through three sets of connecting rods. The ratio of the outer diameter of the driving hydraulic cylinder to the inner diameter of the lateral connecting pipe is 1:3.

[0014] In this invention, an outer arc jet nozzle is provided at the lower end of the protective gas metal injection pipe, several sets of support rods are fixedly installed on the outer wall of the protective gas metal injection pipe, a sleeve is fixedly installed on the outer wall of the flap rotating plate, the sleeve is rotatably sleeved on the outside of the support rod, a torsion return spring is sleeved between the support rod and the end of the sleeve, and the flap rotating plate is covered on the outside of the outer arc jet nozzle.

[0015] In this invention, an end cap is fixedly installed on the outer end of the lateral sliding cylinder, a dustproof mesh plate is fixedly installed on the end cap, a guide bend is fixedly installed on the side of the end cap, an oblique support is fixedly connected between the guide bend and the end cap, the steel wire cable slides through the guide bend, several sets of petal rotating plates are stacked alternately in sequence, and adjacent two petal rotating plates are arranged vertically and vertically in the thickness direction and have overlapping edge areas in the planar direction. A rotation gap is left between the petal rotating plates and the outer wall of the protective gas metal injection pipe.

[0016] In this invention, the gas delivery hose is threadedly connected to the upper end of the protective gas metal injection pipe via a connecting screw joint. The outer wall of the connecting screw joint is provided with anti-slip texture, and the sealing ring has a closed cavity inside, in which the porous elastic rubber particles are filled.

[0017] Compared with related technologies, the laser welding robot for steel structure welding reinforcement proposed in this invention has the following beneficial effects:

[0018] In this invention, a laser welding robot for steel structure welding and reinforcement utilizes Bernoulli's principle to adaptively adjust the spray angle through an adaptive spray angle fine-tuning mechanism. When the laser welding power and shielding gas flow rate increase, the gas velocity within the shielding gas metal spray pipe rises. Based on the fluid mechanics principle that velocity is inversely proportional to static pressure, the internal static pressure decreases. Consequently, the pressure within the drive hydraulic cylinder, connected to the lateral connecting pipe, decreases. Under the pressure difference on both sides, the sealed piston disc pushes the power input telescopic rod inward, compressing it and supplying hydraulic oil from the drive hydraulic cylinder to the driven hydraulic cylinder via a hydraulic hose. This extends the driven telescopic rod, causing the shielding gas metal spray pipe to rotate counterclockwise around the rotating shaft, reducing the tilt angle and making the high-speed airflow more perpendicular to the molten pool surface, effectively suppressing the plasma shielding effect. When the flow rate decreases, the pressure difference weakens, the driven telescopic rod retracts, and the tilt angle increases, preventing the airflow from impacting the molten pool and causing indentations or undercuts. The entire adjustment process is driven entirely by changes in gas velocity, requiring no external sensors or servo motors, resulting in rapid response and immunity to harsh environmental conditions.

[0019] In this invention, a laser welding robot for steel structure welding and reinforcement utilizes an adaptive jet nozzle mechanism to dynamically adjust the nozzle opening based on the proportional relationship between flow velocity and dynamic pressure. When the gas flow velocity inside the protective gas metal jet pipe increases, its internal dynamic pressure increases. The pressure inside the lateral slide cylinder, connected to the inside of the jet pipe, also increases. Meanwhile, the piston slide plate is connected to the atmosphere via a dustproof mesh. This pressure difference pushes the piston slide plate inward, causing the rotating discs to rotate upward via steel cables. This slightly increases the nozzle opening formed between the multiple staggered rotating discs, thus slightly expanding the coverage area of ​​the high-flow-rate gas jet. When the flow velocity decreases, the dynamic pressure decreases, and the torsion return spring drives the rotating discs to return to their original position. The nozzle opening then decreases, maintaining a relatively concentrated jet area for the low-flow-rate gas and preventing airflow dispersion that could reduce the protective effect.

[0020] In this invention, a laser welding robot for steel structure welding and reinforcement is provided. Through a sealing connection mechanism, sealing rings filled with porous elastic rubber particles are placed on the inner side of the threaded joints at both ends of the gas supply hose. This effectively absorbs vibration and impact, maintains sealing contact stress for a long time, and ensures the sealing reliability of the entire gas circuit system under high pressure and vibration conditions. Attached Figure Description

[0021] Figure 1 This is a three-dimensional structural schematic diagram of a laser welding robot for steel structure welding reinforcement proposed in this invention;

[0022] Figure 2 This is a partial three-dimensional structural diagram of a laser welding robot for steel structure welding reinforcement proposed in this invention. Figure 1 ;

[0023] Figure 3 This is a partial three-dimensional structural diagram of a laser welding robot for steel structure welding reinforcement proposed in this invention. Figure 2 ;

[0024] Figure 4 Schematic diagram of a partial three-dimensional structure Figure 1 ;

[0025] Figure 5 A schematic diagram of the partial three-dimensional structure. Figure 1 ;

[0026] Figure 6 Schematic diagram of a partial three-dimensional structure Figure 2 ;

[0027] Figure 7 A schematic diagram of the partial three-dimensional structure. Figure 2 ;

[0028] Figure 8 A three-dimensional structural diagram of the adaptive jet angle fine-tuning mechanism;

[0029] Figure 9 A partial three-dimensional structural breakdown of the adaptive injection angle fine-tuning mechanism. Figure 1 ;

[0030] Figure 10 A partial three-dimensional structural breakdown of the adaptive injection angle fine-tuning mechanism. Figure 2 ;

[0031] Figure 11 Schematic diagram of the three-dimensional structure of the adaptive injection nozzle mechanism Figure 1 ;

[0032] Figure 12 A three-dimensional cross-sectional schematic diagram of the adaptive injection nozzle mechanism;

[0033] Figure 13 Schematic diagram of the three-dimensional structure of the adaptive injection nozzle mechanism Figure 2 ;

[0034] Figure 14 A partial three-dimensional structural diagram of the adaptive injection nozzle mechanism;

[0035] Figure 15 A partial three-dimensional structural breakdown diagram of the adaptive injection nozzle mechanism;

[0036] Figure 16 A three-dimensional structural diagram of the sealing connection mechanism;

[0037] Figure 17 This is a schematic diagram of the three-dimensional cross-sectional structure of the sealing ring.

[0038] In the diagram: 1. Multi-axis robotic arm; 2. Flange connecting plate; 3. Terminal block; 4. Laser welding head; 5. Structural folding seat; 51. Stiffening rib; 52. Rotating shaft seat; 6. Protective gas metal injection pipe; 61. Outer arc air nozzle; 7. Adaptive injection angle fine-tuning mechanism; 71. Connecting seat; 72. Driven hydraulic cylinder; 73. Driven telescopic rod; 74. Ball seat; 75. First oil pipe; 76. Lateral connecting pipe; 77. Dustproof vent cover; 78. Drive hydraulic cylinder; 79. Power input telescopic rod; 710. Sealing... 711. Piston disc; 712. Second oil pipe; 713. Hydraulic hose; 8. Adaptive injection port mechanism; 84. Lateral slide; 85. Flap rotating plate; 86. Support rod; 87. Sleeve; 88. Torque return spring; 89. End cap; 80. Dustproof mesh plate; 810. Guide bend; 811. Diagonal support; 92. Piston slide plate; 93. Steel wire cable; 94. Sealing connection mechanism; 95. Gas supply hose; 96. Butt bolt joint; 97. Anti-slip texture; 98. Sealing ring; 99. Porous elastic rubber granules. Detailed Implementation

[0039] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0040] First embodiment: Please refer to the following: Figures 1-10 In the first embodiment of the present invention, a laser welding robot for steel structure welding reinforcement includes a multi-axis robotic arm 1, an adaptive spray angle fine-tuning mechanism 7, an adaptive spray nozzle mechanism 8, and a sealing connection mechanism 9. A flange connecting plate 2 is bolted to the end of the multi-axis robotic arm 1. A protective gas metal spray pipe 6 is provided on the lower side of the flange connecting plate 2. The adaptive spray angle fine-tuning mechanism 7 includes a driven hydraulic cylinder 72 and a lateral connecting pipe 76. A driven telescopic rod 73 is slidably installed inside the driven hydraulic cylinder 72. A driving hydraulic cylinder 78 is provided at the center of the lateral connecting pipe 76. A power input telescopic rod 79 is slidably installed inside the driving hydraulic cylinder 78. A sealing piston plate 710 is fixedly installed at the end of the power input telescopic rod 79. The sealing piston plate 710 slides in contact with the inner wall of the lateral connecting pipe 76. The tilt adjustment angle range of the protective gas metal spray pipe 6 is ±5°.

[0041] With the above-described configuration, when high-speed protective gas is introduced into the protective gas metal injection pipe 6, its internal flow velocity increases and static pressure decreases. This low pressure is transmitted to the chamber where the drive hydraulic cylinder 78 is located via the lateral connecting pipe 76, creating a pressure difference on both sides of the sealed piston disc 710. This pressure difference pushes the power input telescopic rod 79 inward, compressing hydraulic oil through the second oil pipe 711, hydraulic hose 712, and first oil pipe 75 into the driven hydraulic cylinder 72. This pushes the driven telescopic rod 73 to extend, thereby driving the protective gas metal injection pipe 6 to rotate around the rotating shaft seat 52, achieving adaptive adjustment of the tilt angle within a range of ±5°. During this process, the airflow state of the protective gas metal injection pipe 6 itself directly serves as the control signal source, without the need for external sensor intervention.

[0042] In this embodiment, a first oil pipe 75 is fixedly connected to the bottom of the driven hydraulic cylinder 72, and a second oil pipe 711 is fixedly connected to the bottom of the driving hydraulic cylinder 78. A hydraulic hose 712 is connected between the first oil pipe 75 and the second oil pipe 711.

[0043] With the above configuration, the driving hydraulic cylinder 78 and the driven hydraulic cylinder 72 are connected via the first oil pipe 75, the second oil pipe 711, and the hydraulic hose 712, forming a closed hydraulic transmission circuit. The ratio of the inner diameter of the driving hydraulic cylinder 78 to the inner diameter of the driven hydraulic cylinder 72 is 1:4, which allows the small piston displacement in the driving hydraulic cylinder 78 to obtain a sufficiently large driving force at the end of the driven hydraulic cylinder 72 after hydraulic amplification.

[0044] More importantly, because this hydraulic circuit is a closed system, when the pressure difference on both sides of the sealed piston disc 710 reaches equilibrium and the power input telescopic rod 79 stops moving, the oil pressure on both sides of the piston in the driven hydraulic cylinder 72 tends to balance. At this time, the holding force of the driven telescopic rod 73 mainly comes from the static friction between the piston seal ring and the cylinder wall in the driven hydraulic cylinder 72. When external vibration or airflow impact attempts to drive the protective gas metal injection pipe 6 to rotate, this torque is transmitted in the opposite direction to the driven telescopic rod 73. It must first overcome the static friction between the piston seal ring and the cylinder wall before displacement can occur. This static friction is sufficient to balance the axial component force generated by external disturbance when the piston is stationary, thereby stably holding the protective gas metal injection pipe 6 at any adjustable angle and achieving a self-locking effect.

[0045] In this embodiment, a terminal block 3, a laser welding head 4, and a structural folding seat 5 are fixedly installed on the lower side of the flange connecting plate 2. A stiffening rib 51 is provided at the folding corner of the structural folding seat 5. A rotating shaft seat 52 is fixedly installed on the side wall of the structural folding seat 5. A protective gas metal injection pipe 6 is rotatably installed on the rotating shaft seat 52. A dustproof and ventilated buckle cover 77 is fastened to the end of the lateral connecting pipe 76. A ball seat 74 is fixedly installed at the end of the driven telescopic rod 73. The ball seat 74 is fixedly installed on the side wall of the structural folding seat 5.

[0046] With the above configuration, the terminal block 3 is used to connect to external control circuits, the laser welding head 4 performs welding operations, and the structural folding seat 5 provides a mounting base for each component. The stiffening ribs 51 at its bends enhance the bending stiffness of the structural folding seat 5 and prevent deformation due to vibration or stress during welding. The rotating shaft seat 52 provides a rotation fulcrum for the protective gas metal injection pipe 6, and the ball seat 74 converts the linear motion of the driven telescopic rod 73 into a rotational drive for the protective gas metal injection pipe 6, ensuring smooth motion transmission and avoiding motion interference.

[0047] In this embodiment, the ratio of the inner diameter of the driving hydraulic cylinder 78 to the inner diameter of the driven hydraulic cylinder 72 is 1:4. A connecting seat 71 is fixedly installed on the outer wall of the protective gas metal injection pipe 6, and the driven hydraulic cylinder 72 is rotatably installed inside the connecting seat 71.

[0048] By setting the inner diameter of the driving hydraulic cylinder 78 to that of the driven hydraulic cylinder 72 in a ratio of 1:4, a hydraulic amplification effect is achieved. The connecting seat 71 on the outer wall of the protective gas metal injection pipe 6 provides a rotation mounting point for the driven hydraulic cylinder 72, enabling the driven hydraulic cylinder 72 to adaptively adjust its posture when pushing the protective gas metal injection pipe 6 to rotate, thus avoiding motion interference.

[0049] In this embodiment, the lateral connecting pipe 76 is connected to the interior of the protective gas metal injection pipe 6. The inner wall of the lateral connecting pipe 76 is fixedly connected to the outer wall of the driving hydraulic cylinder 78 through three sets of connecting rods. The ratio of the outer diameter of the driving hydraulic cylinder 78 to the inner diameter of the lateral connecting pipe 76 is 1:3.

[0050] With the above configuration, the lateral connecting pipe 76 is internally connected to the protective gas metal injection pipe 6, ensuring that static pressure changes within the protective gas metal injection pipe 6 can be transmitted to the chamber where the drive hydraulic cylinder 78 is located in real time. The ratio of the outer diameter of the drive hydraulic cylinder 78 to the inner diameter of the lateral connecting pipe 76 is 1:3, forming an annular airflow channel between the inner wall of the lateral connecting pipe 76 and the outer wall of the drive hydraulic cylinder 78, ensuring the sensitivity and response speed of the air pressure signal transmission.

[0051] Second embodiment: Please refer to the following: Figures 11-15 In this embodiment, the adaptive injection port mechanism 8 includes several sets of lateral sliding cylinders 81 and flap rotating plates 82. Several sets of lateral sliding cylinders 81 are circumferentially and fixedly installed on the side wall at the port of the protective gas metal injection pipe 6. The lateral sliding cylinders 81 are connected to the inner side of the protective gas metal injection pipe 6. A piston slide plate 810 is slidably installed on the inner wall of the lateral sliding cylinder 81. A steel wire cable 811 is fixedly connected between the piston slide plate 810 and the flap rotating plate 82.

[0052] With the above-described configuration, when the gas flow velocity within the protective gas metal injection pipe 6 increases, its internal dynamic pressure increases. This pressure is transmitted to the inner cavity of the lateral slide 81 via the connection between the lateral slide 81 and the inner side of the protective gas metal injection pipe 6. This pushes the piston slide plate 810 to slide inward, and through the steel wire cable 811, it pulls the flap rotating plate 82 to overcome the elastic force of the torsion return spring 85 and rotate upward. This increases the opening of the jet nozzle formed between the multiple staggered flap rotating plates 82 covering the outer arc jet nozzle 61, thus slightly expanding the spray coverage area of ​​the large-flow gas. This structure utilizes the dynamic pressure generated by the change in gas flow velocity as the driving force, requiring no external energy input.

[0053] In this embodiment, an outer arc jet nozzle 61 is provided at the lower end of the protective gas metal jet pipe 6. Several sets of support rods 83 are fixedly installed on the outer wall of the protective gas metal jet pipe 6. A sleeve 84 is fixedly installed on the outer wall of the flap rotating plate 82. The sleeve 84 is rotatably sleeved on the outside of the support rods 83. A torsion return spring 85 is sleeved between the end of the support rods 83 and the sleeve 84. The flap rotating plate 82 covers the outside of the outer arc jet nozzle 61.

[0054] With the above-described configuration, the outer arc-shaped jet nozzle 61 is used to eject the protective gas in an arc-shaped diffusion manner, improving the uniformity of gas coverage. The support rod 83 provides rotational support for the flap rotating plate 82, and the sleeve 84 is rotatably fitted onto the outside of the support rod 83, allowing the flap rotating plate 82 to rotate freely around the axis of the support rod 83. A torsion return spring 85 is fitted between the support rod 83 and the end of the sleeve 84, providing a return torque when the gas flow rate decreases, driving the flap rotating plate 82 to rotate back to its initial position, thus restoring the jet nozzle opening to its initial state.

[0055] In this embodiment, an end cap 86 is fixedly installed on the outer end of the lateral slide tube 81, a dustproof mesh plate 87 is fixedly installed on the end cap 86, a guide bend 88 is fixedly installed on the side of the end cap 86, an inclined support 89 is fixedly connected between the guide bend 88 and the end cap 86, a steel wire cable 811 slides through the guide bend 88, several sets of petal rotating plates 82 are stacked alternately in sequence, and two adjacent petal rotating plates 82 are arranged vertically and vertically in the thickness direction and have overlapping edge areas in the planar direction. A rotation gap is left between the petal rotating plates 82 and the outer wall of the protective gas metal injection pipe 6.

[0056] Through the above-described configuration, the end cap 86 seals the outer end of the lateral slide cylinder 81, the dustproof mesh plate 87 prevents external dust from entering the interior of the lateral slide cylinder 81 and affecting the normal sliding of the piston slide plate 810, and the guide bend 88 provides guidance and constraint for the steel wire cable 811, ensuring that the steel wire cable 811 maintains accurate direction and force during traction. Multiple petal rotating plates 82 are stacked alternately, with adjacent petal rotating plates 82 staggered vertically in the thickness direction and having overlapping edge areas in the planar direction, ensuring that the opening of the air jet formed by each petal rotating plate 82 during synchronous rotation changes continuously and uniformly; the rotation gap between the petal rotating plate 82 and the outer wall of the protective gas metal injection pipe 6 ensures no interference or jamming during rotation.

[0057] Third embodiment: Please refer to the following: Figures 16-17 In this embodiment, the sealing connection mechanism 9 includes a gas supply hose 91, both ends of which are fixedly connected to a mating screw joint 92. A sealing ring 94 is provided inside the mating screw joint 92, and the sealing ring 94 is filled with porous elastic rubber particles 95.

[0058] With the above-described configuration, the gas delivery hose 91 is connected to the external gas source and the upper end of the protective gas metal injection pipe 6 via two end screw joints 92, respectively, achieving flexible delivery of the protective gas. The sealing ring 94, gasketed inside the screw joint 92, is subjected to axial compression when the joint is tightened. The porous elastic rubber particles 95 inside absorb vibration energy through the elastic deformation of the porous structure during compression, while maintaining stable contact stress, ensuring that no leakage occurs at the connection point under high-pressure gas impact and welding vibration conditions.

[0059] In this embodiment, the gas delivery hose 91 is threadedly connected to the upper end of the protective gas metal injection pipe 6 via a mating screw connector 92. The outer wall of the mating screw connector 92 is provided with anti-slip texture 93, and the sealing ring 94 has a closed cavity inside, which is filled with porous elastic rubber particles 95.

[0060] With the above-described configuration, the gas delivery hose 91 is threadedly connected to the upper end of the protective gas metal injection pipe 6 via a mating screw connector 92, ensuring a reliable connection and facilitating disassembly and maintenance. The anti-slip texture 93 on the outer wall of the mating screw connector 92 facilitates manual tightening. The porous elastic rubber particles 95 filling the closed cavity inside the sealing ring 94 provide additional elastic compensation when the sealing ring 94 is compressed, maintaining the sealing contact stress. When the system is subjected to vibration and impact, the porous structure absorbs some energy through pore wall deformation, reducing the dynamic load transmitted to the sealing interface, thereby maintaining long-term sealing reliability.

[0061] It should be noted that the multi-axis robotic arm 1 mentioned in this specification is a conventional multi-axis industrial robot in the prior art, which integrates a motion control system and can achieve automated welding trajectory control through pre-programming. This control method is a well-known technology in the art and is not an improvement of this invention. The terminal block 3 is used to realize the electrical connection between the multi-axis robotic arm 1 and the laser welding head 4, and to receive unified scheduling and control commands from the control system of the multi-axis robotic arm 1. The other end of the gas supply hose 91 is connected to an external protective gas storage tank, which has a built-in flow regulating valve. Before operation, the operator presets the protective gas flow rate value according to the welding process requirements. This flow rate is kept constant during the welding process. This gas supply and flow rate preset method is also common knowledge in the art. In addition, laser welding is a non-contact welding method, and its welding area has a low diffusion temperature, which will not cause high temperature effects on the non-contact protective gas metal jet pipe 6 and the components on it. The aforementioned multi-axis robotic arm 1, terminal block 3, laser welding head 4, protective gas storage tank and its flow regulating valve, as well as their interconnections and cooperation relationships, are all existing technical means well known to those skilled in the art. After reading the contents shown in this specification and the accompanying drawings, those skilled in the art can completely reproduce the technical solution described in this invention without creative effort, in conjunction with common knowledge in the field.

[0062] The working principle of the laser welding robot for steel structure welding reinforcement provided by this invention is as follows:

[0063] When protective gas is introduced into the protective gas metal injection pipe 6, its internal flow velocity is inversely proportional to its static pressure. As the laser welding power increases, the protective gas flow rate increases simultaneously, leading to a rise in gas velocity within the protective gas metal injection pipe 6. According to Bernoulli's principle, this causes a decrease in internal static pressure. This low pressure is transmitted via the lateral connecting pipe 76 to the chamber containing the driving hydraulic cylinder 78, creating a pressure difference across the sealed piston disc 710. This pressure difference pushes the power input telescopic rod 79 inward, compressing hydraulic oil through the second oil pipe 711, hydraulic hose 712, and the first oil pipe 75 into the driven hydraulic cylinder 72. This causes the driven telescopic rod 73 to extend, driving the protective gas metal injection pipe 6 to rotate counterclockwise around the rotating shaft 52. The reduced inclination angle makes the high-speed airflow more perpendicular to the molten pool surface, effectively suppressing the plasma shielding effect. When the laser welding power decreases, the shielding gas flow rate decreases simultaneously, the gas velocity in the shielding gas metal jet pipe 6 decreases, the static pressure rises, the pressure difference on both sides of the sealing piston disc 710 weakens, the driven telescopic rod 73 retracts, and the shielding gas metal jet pipe 6 rotates clockwise around the rotating shaft seat 52, increasing the tilt angle to avoid the gas flow impacting the molten pool and causing dents or undercuts.

[0064] As the gas flow rate changes within the protective gas metal injection pipe 6, its internal dynamic pressure also changes accordingly. When the laser welding power increases and the gas flow rate rises, the internal dynamic pressure of the protective gas metal injection pipe 6 increases. The pressure inside the lateral slide 81, connected to the inside of the protective gas metal injection pipe 6, also increases. Meanwhile, the outer side of the piston slide plate 810 is connected to the atmosphere through the dustproof mesh plate 87. The pressure difference between the inside and outside pushes the piston slide plate 810 to slide inwards. This causes the valve plate 82 to rotate upwards against the force of the torsion return spring 85 via the steel wire cable 811, slightly increasing the opening of the jet nozzle formed between the multiple staggered valve plates 82, thus slightly expanding the coverage area of ​​the high-flow-rate gas injection. When the laser welding power decreases and the gas flow rate decreases, the dynamic pressure decreases, and the torsion return spring 85 drives the valve plate 82 to return to its original position. The opening of the jet nozzle decreases accordingly, keeping the low-flow-rate gas in a relatively concentrated injection area and preventing airflow dispersion that could reduce the protective effect.

[0065] Both the adaptive jet angle fine-tuning mechanism 7 and the adaptive jet nozzle mechanism 8 are driven simultaneously by changes in the flow rate of the shielding gas itself. During the process of increasing laser welding power, the adaptive jet angle fine-tuning mechanism 7 reduces the inclination angle of the shielding gas metal jet pipe 6, making the airflow more perpendicular to the molten pool to suppress plasma shielding; the adaptive jet nozzle mechanism 8 slightly increases the opening of the jet nozzles between the flap rotating plates 82 to expand the jet coverage area. During the process of decreasing laser welding power, the adaptive jet angle fine-tuning mechanism 7 increases the inclination angle of the shielding gas metal jet pipe 6 to avoid airflow impacting the molten pool; the adaptive jet nozzle mechanism 8 decreases the jet nozzle opening to maintain concentrated gas jetting. Neither requires external sensors or servo motors; both are driven entirely by changes in the same gas source parameters, responding in tandem.

[0066] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A laser welding robot for steel structure welding reinforcement, characterized in that, include: A multi-axis robotic arm (1) is provided with a flange connection plate (2) at the end of the multi-axis robotic arm (1) and a protective gas metal injection pipe (6) is provided on the lower side of the flange connection plate (2). An adaptive injection angle fine-tuning mechanism (7) is provided, comprising a driven hydraulic cylinder (72) and a lateral connecting pipe (76). A driven telescopic rod (73) is slidably installed inside the driven hydraulic cylinder (72). A driving hydraulic cylinder (78) is provided at the center of the lateral connecting pipe (76). A power input telescopic rod (79) is slidably installed inside the driving hydraulic cylinder (78). A sealing piston disc (710) is installed at the end of the power input telescopic rod (79). The sealing piston disc (710) slides in contact with the inner wall of the lateral connecting pipe (76). The tilt adjustment angle range of the protective gas metal injection pipe (6) is ±5°. Adaptive injection nozzle mechanism (8); Sealing connection mechanism (9).

2. The laser welding robot for steel structure welding reinforcement according to claim 1, characterized in that, The adaptive injection port mechanism (8) includes several sets of lateral slide cylinders (81) and flap rotating plates (82). The several sets of lateral slide cylinders (81) are circumferentially and equidistantly installed on the side wall at the port of the protective gas metal injection pipe (6). The lateral slide cylinders (81) are connected to the inner side of the protective gas metal injection pipe (6). A piston slide plate (810) is slidably installed on the inner wall of the lateral slide cylinder (81). A steel wire cable (811) is connected between the piston slide plate (810) and the flap rotating plate (82).

3. The laser welding robot for steel structure welding reinforcement according to claim 1, characterized in that, The sealing connection mechanism (9) includes a gas supply hose (91), both ends of which are provided with a connecting screw joint (92). A sealing ring (94) is provided on the inner side of the connecting screw joint (92), and the sealing ring (94) is filled with porous elastic rubber particles (95).

4. The laser welding robot for steel structure welding reinforcement according to claim 1, characterized in that, The driven hydraulic cylinder (72) is equipped with a first oil pipe (75) at its bottom, and the driven hydraulic cylinder (78) is equipped with a second oil pipe (711) at its bottom. A hydraulic hose (712) is installed between the first oil pipe (75) and the second oil pipe (711).

5. The laser welding robot for steel structure welding reinforcement according to claim 1, characterized in that, The flange connecting plate (2) is equipped with a terminal block (3), a laser welding head (4) and a structural folding seat (5) on its lower side. The structural folding seat (5) is provided with stiffening ribs (51) at the folding corner. A rotating shaft seat (52) is installed on the side wall of the structural folding seat (5). The protective gas metal injection pipe (6) is rotatably installed on the rotating shaft seat (52). The end of the lateral connecting pipe (76) is fastened with a dustproof ventilation cap (77). The end of the driven telescopic rod (73) is equipped with a ball seat (74). The ball seat (74) is installed on the side wall of the structural folding seat (5).

6. The laser welding robot for steel structure welding reinforcement according to claim 1, characterized in that, The ratio of the inner diameter of the driving hydraulic cylinder (78) to the inner diameter of the driven hydraulic cylinder (72) is 1:

4. A connecting seat (71) is installed on the outer wall of the protective gas metal injection pipe (6). The driven hydraulic cylinder (72) is rotatably installed inside the connecting seat (71).

7. The laser welding robot for steel structure welding reinforcement according to claim 1, characterized in that, The lateral connecting pipe (76) is internally connected to the protective gas metal injection pipe (6), and the ratio of the outer diameter of the driving hydraulic cylinder (78) to the inner diameter of the lateral connecting pipe (76) is 1:

3.

8. A laser welding robot for steel structure welding reinforcement according to claim 2, characterized in that, An outer arc jet nozzle (61) is provided at the lower end of the protective gas metal jet pipe (6). Several sets of support rods (83) are installed on the outer wall of the protective gas metal jet pipe (6). A sleeve (84) is installed on the outer wall of the flap rotating plate (82). The sleeve (84) is rotatably sleeved on the outside of the support rod (83). A torsion return spring (85) is sleeved between the support rod (83) and the end of the sleeve (84). The flap rotating plate (82) covers the outside of the outer arc jet nozzle (61).

9. A laser welding robot for steel structure welding reinforcement according to claim 2, characterized in that, An end cap (86) is installed on the outer end of the lateral slide tube (81). A dustproof mesh plate (87) is installed on the end cap (86). A guide bend (88) is installed on the side of the end cap (86). An oblique support (89) is provided between the guide bend (88) and the end cap (86). The steel wire cable (811) slides through the guide bend (88). Several sets of petal rotating plates (82) are stacked alternately in sequence. Two adjacent petal rotating plates (82) are arranged vertically and vertically in the thickness direction and have overlapping edge areas in the plane direction. A rotation gap is left between the petal rotating plate (82) and the outer wall of the protective gas metal injection pipe (6).

10. A laser welding robot for steel structure welding reinforcement according to claim 3, characterized in that, The gas delivery hose (91) is connected to the upper end of the protective gas metal injection pipe (6) via a connecting screw (92). The connecting screw (92) has anti-slip texture (93) on its outer wall. The sealing ring (94) has a closed cavity inside, and the porous elastic rubber particles (95) are filled in the closed cavity.

Images