Method for surfacing a side sill positioning arm

Abstract

This invention relates to the field of welding and provides a method for surfacing welding of a side beam positioning arm. The method includes dividing the area to be welded on the side beam positioning arm, which has a complex geometry, into at least two sub-process zones based on the weld direction and heat-affected zone distribution, and independently pre-setting a set of welding process parameters for each sub-process zone; employing compressed arc welding technology, driving a welding torch along a predetermined welding path to perform single-pass continuous automatic surfacing welding of the area to be welded, thereby completing the weld deposition and formation in one pass; during the single-pass continuous automatic surfacing welding process, the spatial position of the welding torch is monitored in real time, and when the welding torch moves from one sub-process zone to the next, the welding process parameters being executed are switched from the preset parameter set for the previous sub-process zone to the preset parameter set for the next sub-process zone. This surfacing welding method for a side beam positioning arm can achieve one-time forming of complex structures with high quality and efficiency, and can avoid rework.

Description

Technical Field

[0001] This invention relates to the field of welding, and provides a method for overlay welding of a side beam positioning arm. Background Technology

[0002] Welding technology is a crucial step in the manufacturing process of the side beam positioning arm for rail vehicles, directly affecting the product's high strength, high sealing performance, and fatigue life. However, existing welding technologies face several challenges in practical applications. First, for complex welds such as ring or saddle-shaped welds, current welding methods struggle to achieve one-time forming, significantly impacting production efficiency. Furthermore, multiple welding operations can easily lead to defects such as incomplete fusion, slag inclusions, and porosity. These problems not only increase the production cycle but can also result in inconsistent weld quality, affecting the product's long-term usability.

[0003] Secondly, when welds intersect, such as when a circumferential weld intersects a straight weld or other welds, the superposition of heat input, stress concentration, and abrupt changes in the flow state of the molten pool make it difficult for existing technologies to effectively control the quality of this area. Defects such as porosity, incomplete penetration, undercut, and even cracks often occur. These defects significantly increase the product rework rate, not only increasing labor time and costs but also potentially leading to a decline in the performance of the base material due to repeated welding repairs.

[0004] Third, complex structural parts such as the dovetail corners on the positioning arms of rail vehicle side beams, due to their complex spatial structure and variable welding angles, are difficult for existing automated welding equipment and methods to fully meet. Often, problems such as unreachable welding torches, difficulties in trajectory planning, and poor shielding gas coverage lead to unstable welding processes, necessitating manual operation by skilled welders. This is not only inefficient and labor-intensive but also fails to guarantee consistent quality, creating a bottleneck and quality risk point in the production process. Summary of the Invention

[0005] This invention provides a welding method for side beam positioning arms, which enables efficient, stable, and high-quality automatic welding of side beam positioning arms.

[0006] This invention provides a welding method for a side beam positioning arm, comprising: The welding area with complex geometry on the side beam positioning arm is divided into at least two sub-process areas according to the weld direction and heat-affected zone distribution, and a set of welding process parameters is preset independently for each sub-process area. The compression arc welding technology is used to drive the welding torch to perform single-pass continuous automatic surfacing welding on the area to be welded along a predetermined welding path, so as to complete the fusion formation of the weld in one go. During the single-pass continuous automatic welding process, the spatial position of the welding torch is monitored in real time. When the welding torch moves from one sub-process area to the next sub-process area, the welding process parameters being executed are switched from the preset parameter set for the previous sub-process area to the preset parameter set for the next sub-process area.

[0007] According to one embodiment of the present invention, the preset parameter group of the welding process parameters includes at least one of welding current, arc voltage, welding speed, wire feed speed, the oscillation mode of the welding torch, arc initiation strategy and arc termination strategy.

[0008] According to one embodiment of the present invention, the area to be welded includes annular welds and / or saddle-shaped welds.

[0009] According to one embodiment of the present invention, at least one of the sub-process areas is a weld intersection area, and the other of the sub-process areas is a non-weld intersection area.

[0010] According to one embodiment of the present invention, the welding process parameters corresponding to the weld intersection area are first welding process parameters. The first welding process parameters include reducing the welding speed and / or changing the oscillation mode of the welding torch to actively control the heat input and molten pool solidification behavior of the weld intersection area.

[0011] According to one embodiment of the present invention, before performing the single-pass continuous automatic welding, the method further includes: A three-dimensional digital model of the side beam positioning arm is performed, and the welding path of the single-pass continuous automatic overlay welding is planned based on the three-dimensional digital model.

[0012] According to one embodiment of the present invention, the welding path is a continuous and smooth trajectory that ensures a smooth transition in the posture of the welding torch.

[0013] According to one embodiment of the present invention, the single-pass continuous automatic welding is performed by an automated workstation consisting of a high-degree-of-freedom welding robot and a positioner.

[0014] According to one embodiment of the present invention, the area to be welded includes a dovetail structure, and the welding method for the side beam positioning arm further includes: When welding the dovetail structure, the high-degree-of-freedom welding robot, combined with attitude calculation technology, dynamically plans and adjusts the attitude of the welding torch in real time to ensure that the welding torch reaches and covers all the surfaces to be welded on the dovetail structure at a preset angle.

[0015] According to one embodiment of the present invention, when welding the dovetail structure, a local protective gas nozzle is used to ensure gas protection of the weld pool within the narrow space of the dovetail structure.

[0016] According to one embodiment of the present invention, the area to be welded includes a stiffener joint, and the welding method for the side beam positioning arm further includes: When welding the stiffener joint, a preset oscillation technique for the welding torch is used, and the centering position and welding angle of the welding torch are controlled to ensure good fusion at the root of the stiffener joint and suppress undercut in the weld toe area.

[0017] According to one embodiment of the present invention, the control system of the high-degree-of-freedom welding robot compares the real-time position coordinates of the welding torch with the preset boundary coordinates of the sub-process area to trigger the switching of welding process parameters.

[0018] According to one embodiment of the present invention, in the step of performing single-pass continuous automatic surfacing welding, the single-pass continuous automatic surfacing welding forms a single-pass weld on the area to be welded to avoid interlayer lack of fusion or slag inclusion defects caused by multi-pass welding.

[0019] The welding method for side beam positioning arms provided by this invention divides the welding area into sub-process zones based on the weld direction and heat-affected zone distribution, solving the problem that a single parameter is insufficient to adapt to the welding requirements of different areas in complex geometric welding regions. Each sub-process zone has independently preset and adapted welding process parameters, ensuring optimal welding conditions for each area and avoiding localized incomplete fusion, overheating, or poor forming caused by a single parameter setting, thus laying the foundation for high-quality subsequent welding. The use of compression arc welding technology achieves single-pass continuous automatic welding. Its high energy density ensures one-time weld deposition, completely eliminating defects such as interlayer incomplete fusion, slag inclusions, and porosity that are easily generated in traditional multi-pass welding, improving weld density and metallurgical bonding quality. Simultaneously, single-pass continuous welding significantly shortens the welding cycle, avoiding quality fluctuations caused by repeated arc starting and ending in multi-pass welding, and significantly improving production efficiency. The real-time position monitoring and parameter switching mechanism ensures that the welding torch can adapt to new parameters in a timely manner at the junction of different sub-process areas, avoiding quality weaknesses caused by parameter mismatch at the regional transition and ensuring the uniformity of the weld quality. The smooth parameter switching process maintains arc stability and molten pool morphology stability, further reducing the risk of welding defects. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1This is a schematic flowchart of the welding method for the side beam positioning arm provided by the present invention.

[0022] Figure 2 This is a schematic diagram illustrating the steps of the welding method for the side beam positioning arm provided by the present invention. Detailed Implementation

[0023] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0024] like Figures 1 to 2 As shown, an embodiment of the present invention provides a welding method for a side beam positioning arm, comprising: Step 10: Divide the area to be welded on the side beam positioning arm with a complex geometric shape into at least two sub-process areas according to the weld direction and heat-affected zone distribution, and preset a set of welding process parameters for each sub-process area independently. Step 20: Using compression arc welding technology, drive the welding torch along the predetermined welding path to perform single-pass continuous automatic surfacing welding on the area to be welded, so as to complete the weld deposition and formation in one go. Step 30: During the single-pass continuous automatic welding process, the spatial position of the welding torch is monitored in real time. When the welding torch moves from one sub-process area to the next sub-process area, the welding process parameters being executed are switched from the preset parameter set used for the previous sub-process area to the preset parameter set used for the next sub-process area.

[0025] The welding method for side beam positioning arms provided by this invention divides the welding area into sub-process zones based on the weld direction and heat-affected zone distribution, solving the problem that a single parameter is insufficient to adapt to the welding requirements of different areas in complex geometric welding regions. Each sub-process zone has independently preset and adapted welding process parameters, ensuring optimal welding conditions for each area and avoiding localized incomplete fusion, overheating, or poor forming caused by a single parameter setting, thus laying the foundation for high-quality subsequent welding. The use of compression arc welding technology achieves single-pass continuous automatic welding. Its high energy density ensures one-time weld deposition, completely eliminating defects such as interlayer incomplete fusion, slag inclusions, and porosity that are easily generated in traditional multi-pass welding, improving weld density and metallurgical bonding quality. Simultaneously, single-pass continuous welding significantly shortens the welding cycle, avoiding quality fluctuations caused by repeated arc starting and ending in multi-pass welding, and significantly improving production efficiency. The real-time position monitoring and parameter switching mechanism ensures that the welding torch can adapt to new parameters in a timely manner at the junction of different sub-process areas, avoiding quality weaknesses caused by parameter mismatch at the regional transition and ensuring the uniformity of the weld quality. The smooth parameter switching process maintains arc stability and molten pool morphology stability, further reducing the risk of welding defects.

[0026] The three steps work together to achieve high-quality welding of the complex welding areas of the side beam positioning arm, significantly improve the automation and stability of the welding process, reduce errors caused by manual intervention, lower the weld rework rate, shorten the production cycle, control manufacturing costs, and provide a reliable guarantee for the mass production and high-quality production of the side beam positioning arm.

[0027] Please continue reading Figures 1 to 2 The welding method for the side beam positioning arm provided in this embodiment of the invention is implemented through three steps, as follows: Step 10 involves a comprehensive analysis of the complex geometry of the welding area of ​​the side beam positioning arm, including the spatial orientation of the weld (e.g., the circumferential extension direction of annular welds and the curved turning direction of saddle-shaped welds) and the distribution of heat effects (e.g., areas where heat input easily accumulates and areas with significant differences in heat conduction). Based on this analysis, the welding area is divided into at least two sub-process zones. During this division, the boundary range of each sub-process zone is clearly defined to ensure that the boundary matches the weld characteristics and heat effect variation trends. Simultaneously, for each sub-process zone, a set of welding process parameters is independently preset based on its structural characteristics (e.g., weld thickness and interference from surrounding structures) and welding requirements (e.g., penetration requirements and forming quality requirements). The preset welding process parameters cover welding current, arc voltage, welding speed, wire feed speed, welding torch oscillation mode, arc initiation strategy, and arc termination strategy. This ensures that each set of parameters is suitable for the welding conditions of the corresponding sub-process zone, and all parameter sets have been verified through prior experiments and stored in the automated control system for future use.

[0028] Step 20 employs compressed arc welding technology as the core welding process. First, the compressed arc welding equipment is started and its status adjusted to ensure the arc possesses high energy density, controllable heat input, and strong arc stability. Then, an automated workstation consisting of a high-degree-of-freedom welding robot and a positioner drives the welding torch, performing single-pass continuous automatic welding along a predetermined welding path on the area to be welded. The predetermined welding path must be planned in advance based on a three-dimensional digital model of the side beam positioning arm. The path must ensure a smooth transition of the welding torch's posture, avoiding sharp bends or sudden angle changes, and avoiding non-welded structures around the area to be welded to prevent interference. During the welding process, the welding torch moves continuously without interruption, the welding wire melts uniformly and fills the weld seam, completing the weld deposition and forming of the entire area to be welded in one go, without the need for intermediate stops or re-welding.

[0029] During step 30, a position detection device installed on the high-degree-of-freedom welding robot collects the spatial coordinates of the welding torch in real time and continuously transmits the coordinate data to the automated control system. The control system pre-stores the boundary coordinates of each sub-process area and compares the real-time position coordinates of the welding torch with the boundary coordinates in real time. When the welding torch is detected moving from the current sub-process area to the boundary of the next sub-process area, the control system immediately triggers a parameter switching command, smoothly switching the welding process parameters from the preset parameter set of the current sub-process area to the preset parameter set of the next sub-process area. During the switching process, parameter adjustments are performed according to a preset transition curve to avoid sudden parameter changes that could lead to arc extinction or molten pool disturbance, ensuring a continuous and stable welding process.

[0030] According to one embodiment of the present invention, the preset parameter group of welding process parameters includes at least one of welding current, arc voltage, welding speed, wire feed speed, welding torch oscillation mode, arc initiation strategy and arc termination strategy.

[0031] In one embodiment of the present invention, the preset welding process parameter set for each sub-process zone covers a variety of key parameters. The welding current is preset according to the weld thickness and thermal conductivity of the base material in the sub-process zone to ensure that the arc energy meets the penetration requirements without overheating; the arc voltage and welding current are preset in tandem to ensure stable arc combustion and avoid excessive spatter or arc extinguishing; the welding speed is set according to the heat input requirements of the sub-process zone to balance welding efficiency and fusion quality; the wire feed speed is matched with the welding current and speed to ensure that the amount of wire melting is consistent with the molten pool filling requirements; the oscillation mode of the welding torch is preset according to the weld width and shape, including oscillation amplitude, frequency, and trajectory to ensure uniform weld formation; the arc initiation strategy is preset to slowly increase the current and wire feed speed to avoid instability of the molten pool at the moment of arc initiation; the arc termination strategy is preset to gradually reduce the heat input and fill the arc crater to avoid depressions or cracks at the arc termination point. All parameter sets are stored in the control system after being verified by experiments and can be called during surfacing welding.

[0032] The coordinated preset of multi-dimensional welding process parameters ensures optimal welding conditions for each sub-process zone, avoiding quality fluctuations caused by adjusting a single parameter. A stable arc and matched wire feed speed reduce spatter and porosity defects, while a reasonable oscillation mode guarantees uniform deposition of wide welds. Scientific arc initiation and termination strategies eliminate weak points at both ends of the weld. The systematic preset of parameter sets enhances the stability and repeatability of the welding process, reduces the impact of human factors on quality, and ensures consistent welding quality across different batches and workpieces.

[0033] According to one embodiment of the present invention, the area to be welded includes annular welds and / or saddle-shaped welds.

[0034] In one embodiment of the invention, the area to be welded is a circumferential weld, a saddle-shaped weld, or a combination of both. For the circumferential weld, its circumferential structural characteristics and radius variation are first analyzed, and sub-process zones are divided according to the circumferential direction and the superposition of heat effects. Each sub-process zone corresponds to a segment on the circumference, and the parameters are preset to consider the centrifugal force effect and heat accumulation effect of circumferential welding. For the saddle-shaped weld, sub-process zones are divided according to its spatial surface variation, saddle point position, and steep slope distribution, with a focus on stress concentration and heat input control at the saddle point. Three-dimensional digital modeling is performed on both types of welds to clarify the spatial coordinates and geometric features of the weld, plan a continuous and smooth welding path, ensure a smooth transition of the welding torch posture, and perform single-pass continuous surfacing welding according to the path using a compressed arc welding equipment, switching parameters according to the sub-process zones during the process.

[0035] By partitioning and optimizing parameters for the complex structural characteristics of circumferential and saddle-shaped welds, the problem of traditional welding adapting to surface variations was solved. A continuous, smooth welding path and precise parameter switching ensure uniform penetration and weld quality on complex curved surfaces, avoiding defects such as incomplete fusion and undercut at critical locations like saddle points and steep slopes. Single-pass continuous welding replaced traditional multi-pass welding, significantly shortening the welding cycle of complex welds while eliminating interlayer defects, improving the weld's mechanical properties and sealing performance, and meeting the high strength and fatigue life requirements of the side beam positioning arm.

[0036] According to one embodiment of the present invention, at least one of the sub-process areas is a weld seam intersection area, and the other sub-process area is a non-weld seam intersection area.

[0037] In one embodiment of the present invention, the sub-process area is clearly divided into weld intersection area and non-weld intersection area. The weld intersection area refers to the intersection of a circumferential weld with a straight weld or different circumferential welds, defined by the degree of stress concentration and the range of heat input superposition. The non-weld intersection area is the part of the weld where no other welds intersect and the stress distribution is uniform. A first welding process parameter is preset for the weld intersection area, and conventional welding process parameters are preset for the non-weld intersection area. During welding, the welding torch first performs single-pass continuous welding in the non-weld intersection area using conventional parameters. When it moves to the boundary of the weld intersection area, the control system switches to the first welding process parameter. After completing the welding in the intersection area, it switches back to the conventional parameters to continue welding the non-intersection area.

[0038] By dividing the weld intersection area into a separate sub-process zone and pre-setting dedicated parameters, the defects caused by superimposed heat input and stress concentration in this area were specifically addressed. Switching between standard parameters and the primary welding process parameters ensured welding efficiency in non-intersection areas and quality stability in intersection areas, avoiding the problem of frequent defects in intersection areas or low efficiency in non-intersection areas caused by a single parameter. The dedicated parameters for intersection areas effectively suppressed defects such as porosity, incomplete penetration, and cracks, while the standard parameters for non-intersection areas ensured welding efficiency. Overall, this improved weld quality consistency and production efficiency, reducing the rework rate.

[0039] According to one embodiment of the present invention, the welding process parameters corresponding to the weld intersection area are first welding process parameters. The first welding process parameters include reducing the welding speed and / or changing the oscillation mode of the welding torch to actively control the heat input and solidification behavior of the weld intersection area.

[0040] In one embodiment of the invention, the first welding process parameters for the weld intersection area are optimized for heat input control and molten pool solidification behavior. Reducing the welding speed extends the residence time of the welding torch in the intersection area, ensuring sufficient heat transfer and preventing incomplete fusion due to insufficient heat input. Changing the welding torch oscillation mode specifically involves reducing the oscillation amplitude and frequency, concentrating arc energy more at the weld root, and optimizing the molten pool flow direction to prevent turbulence caused by stress concentration. Furthermore, the first welding process parameters can also be coordinated with the welding current to appropriately reduce energy input, further controlling the size of the heat-affected zone and reducing stress accumulation. During parameter switching, the control system smoothly adjusts according to a preset transition curve to avoid arc instability caused by sudden parameter changes.

[0041] Reducing the welding speed prolongs the heat treatment time in the intersection area, ensuring full fusion at the weld root and resolving the difficulty in penetration caused by the complex structure of the intersection area. Changing the welding torch oscillation mode makes the molten pool shape more stable, avoiding molten pool flow and slag inclusion defects, while also reducing the risk of cracking due to stress concentration. The coordinated adjustment of parameter combinations effectively controls the heat input and molten pool solidification rate in the intersection area, optimizing the metallurgical bonding effect, completely eliminating common defects in the weld intersection area, improving the strength and toughness of the welded joint, and ensuring the operational reliability of the side beam positioning arm under complex loads.

[0042] According to one embodiment of the present invention, before performing single-pass continuous automatic welding, the method further includes: A three-dimensional digital model of the side beam positioning arm was created, and a welding path for single-pass continuous automatic overlay welding was planned based on the three-dimensional digital model.

[0043] In one embodiment of the present invention, a three-dimensional digital model of the side beam positioning arm is first performed before welding. A three-dimensional scanning device is used to comprehensively scan the area to be welded and the surrounding structure of the side beam positioning arm, obtaining accurate three-dimensional coordinate data and establishing a three-dimensional digital model including the geometric features and structural dimensions of the area to be welded. Based on this model, the spatial surface changes of the area to be welded, the weld direction, and the interference with the surrounding structure are analyzed to plan a single-pass continuous automatic welding path. The path planning focuses on the smooth transition of the welding torch posture, avoiding sharp bends and abrupt angle changes, ensuring that the welding torch maintains the optimal welding angle throughout the welding process, while avoiding interference from the surrounding structure, ensuring a continuous and unobstructed welding process. The planned welding path is imported into the automated control system as the basis for the movement of the welding torch.

[0044] The precise data obtained from 3D digital modeling provides a reliable foundation for path planning, avoiding the biases caused by the reliance on experience in traditional path planning. A continuous and smooth welding path ensures stable welding torch posture, reduces arc fluctuations and forming defects, and improves the geometric accuracy of the weld. Avoiding interference areas during path planning ensures the continuity of the welding process, avoids mid-process adjustments, and improves production efficiency. Model-based path planning can also predict welding difficulties in complex structures in advance, providing a basis for sub-process area division and parameter preset, further enhancing the controllability of welding quality.

[0045] According to one embodiment of the present invention, the welding path is a continuous and smooth trajectory that ensures a smooth transition in the posture of the welding torch.

[0046] In one embodiment of the invention, the core objective of welding path planning is a smooth transition in the welding torch posture. For the complex curved surface of the area to be welded, a curve fitting algorithm is used to generate a continuous and smooth trajectory. The included angle between the tangents of any two adjacent points on the trajectory is controlled within a gradual range, ensuring uniform angle changes of the welding torch during movement, without sudden acceleration or sharp turns. The path planning also considers the motion characteristics of the welding torch, reserving reasonable transition sections to ensure smooth connection of posture and movement speed when the welding torch enters different sub-process areas. Simultaneously, the path avoids non-welded structures of the side beam positioning arm, ensuring interference-free torch movement and guaranteeing the continuity and stability of the welding process.

[0047] A continuous and smooth welding path avoids abrupt changes in the welding torch posture, reducing instability such as arc extinction and increased spatter, ensuring continuous formation of the molten pool, and improving the surface finish and geometric consistency of the weld. Gentle angle changes keep the welding torch in the optimal welding posture at all times, ensuring uniform weld penetration and avoiding defects such as localized incomplete fusion or over-fusion. The path avoids interference areas, ensuring continuous welding, reducing downtime for adjustments, improving production efficiency, and simultaneously preventing collision damage between the welding torch and the workpiece, thus reducing production risks.

[0048] According to one embodiment of the present invention, single-pass continuous automatic welding is performed by an automated workstation consisting of a high-degree-of-freedom welding robot and a positioner.

[0049] In one embodiment of the present invention, single-pass continuous automatic surfacing welding is performed by an automated workstation comprising a high-degree-of-freedom welding robot and a positioner. The high-degree-of-freedom welding robot, equipped with a welding torch, possesses multi-directional movement capabilities and can precisely respond to preset welding paths, achieving surfacing welding on complex spatial trajectories. The positioner is fixedly connected to a side beam positioning arm and can drive the workpiece to rotate around different axes, adjusting the workpiece posture to ensure the area to be welded is always in the optimal welding position. During the surfacing welding process, the control system synchronously coordinates the movements of the high-degree-of-freedom welding robot and the positioner. The robot drives the welding torch along the path, and the positioner synchronously adjusts the workpiece posture to ensure that the welding torch and the surface to be welded always maintain a preset welding angle and distance, achieving continuous surfacing welding in all positions.

[0050] The high-degree-of-freedom welding robot's multi-directional motion capability adapts to the spatial trajectory of complex welding areas, solving the problem of poor welding torch accessibility caused by insufficient motion freedom in traditional robots. The coordinated movement of the positioner and the robot ensures the welding area is always in the optimal welding position, avoiding defects such as poor welding angles and molten pool flow caused by fixed workpiece postures, thus improving the quality stability of all-position welding. The collaborative control of the automated workstation reduces human intervention, avoids quality fluctuations caused by human factors, and significantly improves welding efficiency, shortens the production cycle, and meets the needs of mass production.

[0051] According to one embodiment of the present invention, the area to be welded includes a dovetail structure, and the welding method for the side beam positioning arm further includes: When welding dovetail corner structures, a high-degree-of-freedom welding robot is used in conjunction with attitude calculation technology to dynamically plan and adjust the attitude of the welding torch in real time, so as to ensure that the welding torch reaches and covers all the surfaces to be welded on the dovetail corner structure at a preset angle.

[0052] In one embodiment of the invention, when the area to be welded includes a dovetail structure, the welding process focuses on optimizing the welding torch attitude control. A high-degree-of-freedom welding robot is equipped with an attitude calculation module, which dynamically plans the welding torch's attitude trajectory based on the spatial geometric data of the dovetail structure in a three-dimensional digital model. During welding, the robot acquires its own position and the relative coordinates of the dovetail structure in real time. The attitude calculation module calculates the optimal attitude parameters of the welding torch in real time according to preset welding angle requirements, including pitch angle, swing angle, and rotation angle, driving the welding torch to make real-time adjustments. During the adjustment process, it is ensured that the nozzle of the welding torch is always aligned with the surface to be welded on the dovetail, the tip of the welding wire is precisely pointed towards the root of the weld, covering all areas to be welded, and eliminating welding dead zones.

[0053] The combination of attitude calculation technology and high-degree-of-freedom robots solves the problem of poor weld gun accessibility caused by the narrow space and variable angles of dovetail corner structures, ensuring uniform fusion on all surfaces to be welded. Real-time adjustment of the weld gun attitude keeps the welding wire tip in the optimal welding position, guaranteeing full fusion at the root of the dovetail corner structure and avoiding defects such as incomplete fusion and undercut. Automated attitude control replaces traditional manual welding, eliminating quality fluctuations caused by human factors, improving the consistency and reliability of dovetail corner structure welding quality, while reducing labor intensity and increasing production efficiency.

[0054] According to one embodiment of the present invention, when welding a dovetail corner structure, a local protective gas nozzle is used to ensure gas protection of the weld pool within the narrow space of the dovetail corner structure.

[0055] In one embodiment of the invention, a dedicated local shielding gas nozzle is used when welding dovetail corner structures. This nozzle is designed specifically for the narrow space of dovetail corner structures, featuring a compact size and an outlet shape adapted to the surface to be welded at the dovetail corner. This allows for precise delivery of shielding gas to the molten pool area, forming a locally sealed protective gas shield. The shielding gas is continuously ejected through the nozzle, isolating air from contact with the molten pool. Simultaneously, the nozzle's flow-guiding structure optimizes the gas flow field, preventing turbulence within the confined space and ensuring uniform coverage of the molten pool and heat-affected zone. During the welding process, the nozzle adjusts synchronously with the welding torch posture, maintaining the optimal distance from the surface to be welded, ensuring a continuous and stable protective effect.

[0056] The specialized design of the localized protective gas nozzle solves the problem of poor protective gas coverage in the narrow space of the dovetail corner, avoiding defects such as porosity and oxidation caused by air intrusion and improving the metallurgical quality of the weld. The optimized gas flow field ensures effective coverage of the protective gas, reducing waste and lowering production costs. The continuous and stable protective effect guarantees consistent welding quality for the dovetail corner structure, avoiding rework due to inadequate protection, and further improving production efficiency and product reliability.

[0057] According to one embodiment of the present invention, the area to be welded includes a stiffener joint, and the welding method for the side beam positioning arm further includes: When welding stiffener joints, a preset welding torch oscillation technique is used, and the centering position and welding angle of the welding torch are controlled to ensure good fusion at the root of the stiffener joint and suppress undercut in the weld toe area.

[0058] In one embodiment of the present invention, when the area to be welded includes a stiffener joint, the surfacing welding employs a preset welding torch oscillation technique. Based on the thickness of the stiffener joint and the weld width, the preset oscillation amplitude and frequency of the welding torch are used, with the oscillation trajectory being a symmetrical sawtooth or crescent shape to ensure uniform fusion on both sides of the weld. Simultaneously, the centering position of the welding torch is precisely controlled so that the tip of the welding wire is always aligned with the root center of the stiffener joint, avoiding one-sided incomplete fusion due to misalignment; the welding angle is adjusted to concentrate arc energy at the root, while reducing stress concentration in the weld toe area. During the surfacing welding process, the welding torch moves according to the preset oscillation trajectory and parameters, and the control system monitors the centering position and welding angle in real time to ensure that the parameters remain stable.

[0059] The application of welding torch oscillation technology ensures uniform fusion of the stiffener joint weld, avoiding defects such as incomplete fusion in the middle or undercut on both sides caused by a large weld width. Precise centering control ensures full fusion at the root of the stiffener joint, improving the strength of the welded joint; optimized welding angles reduce stress concentration in the weld toe area, lowering the risk of cracking. Automated parameter control avoids deviations caused by manual operation, improves the consistency of stiffener joint welding quality, meets the structural strength requirements of the side beam positioning arm, and improves welding efficiency, replacing traditional manual repair welding procedures.

[0060] According to one embodiment of the present invention, the control system of a high-degree-of-freedom welding robot compares the real-time position coordinates of the welding torch with the boundary coordinates of a preset sub-process area to trigger the switching of welding process parameters.

[0061] In one embodiment of the invention, parameter switching is triggered via position comparison by the control system. Boundary coordinate data for each sub-process zone are pre-stored in the control system. These coordinates are determined based on the partitioning results of a three-dimensional digital model, clearly defining the spatial range of each sub-process zone. During the welding process, the position detection module of the high-degree-of-freedom welding robot continuously collects the spatial position coordinates of the welding torch and transmits them to the control system. The control system compares the real-time position coordinates with the preset sub-process zone boundary coordinates in real time. When the welding torch's position coordinates reach or cross the boundary coordinates, a parameter switching command is immediately triggered. Following a preset parameter group sequence, the current process parameters are smoothly switched to the preset parameters of the next sub-process zone. The switching process is uninterrupted by the arc, ensuring welding continuity.

[0062] The triggering mechanism based on position coordinate comparison enables precise and real-time parameter switching, avoiding deviations caused by manual judgment of switching timing and ensuring uniform quality transitions between different sub-process zones. Smooth parameter switching avoids arc fluctuations and molten pool instability, reducing forming defects at zone junctions and improving the overall quality consistency of the weld. The automated triggering and switching process requires no manual intervention, improving production efficiency while reducing human error risks, ensuring the stability and repeatability of the welding process, and adapting to mass production needs.

[0063] According to one embodiment of the present invention, in the step of performing single-pass continuous automatic surfacing welding, single-pass continuous automatic surfacing welding forms a single weld on the area to be welded to avoid interlayer lack of fusion or slag inclusion defects caused by multi-pass welding.

[0064] In one embodiment of the present invention, single-pass continuous automatic surfacing welding utilizes the high energy density characteristics of compressed arc welding technology to form a complete single-pass weld in the area to be welded in one operation. Before surfacing, the process parameters of compressed arc welding are optimized according to the thickness and width of the area to be welded, ensuring that the thickness and width of the single-pass deposition meet the design requirements, eliminating the need for subsequent re-welding. During the surfacing process, the welding torch moves continuously along a preset path, the arc burns steadily and continuously, and the welding wire melts uniformly and fills the weld, forming a continuous and dense single-pass weld. The entire process eliminates the repetitive operation of arc initiation and termination, and there are no interlayer interfaces within the weld, completely avoiding the interlayer bonding problems caused by multi-pass welding.

[0065] The formation of a single-pass weld completely eliminates defects such as incomplete fusion, slag inclusions, and porosity caused by multi-pass welding, improving weld density and metallurgical bonding quality, and enhancing the strength and fatigue life of the welded joint. Eliminating the need for multiple weld repairs shortens the production cycle, improves production efficiency, and reduces the number of arc starting and ending operations, avoiding quality weaknesses caused by repeated arc starting and ending. The continuous and dense single-pass weld also improves weld sealing, meeting the sealing requirements of the side beam positioning arm, reducing the risk of corrosion during use, and further ensuring product reliability and service life.

[0066] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A welding method for a side beam positioning arm, characterized in that, include: The welding area with complex geometry on the side beam positioning arm is divided into at least two sub-process areas according to the weld direction and heat-affected zone distribution, and a set of welding process parameters is preset independently for each sub-process area. The compression arc welding technology is used to drive the welding torch to perform single-pass continuous automatic surfacing welding on the area to be welded along a predetermined welding path, so as to complete the fusion formation of the weld in one go. During the single-pass continuous automatic welding process, the spatial position of the welding torch is monitored in real time. When the welding torch moves from one sub-process area to the next sub-process area, the welding process parameters being executed are switched from the preset parameter set for the previous sub-process area to the preset parameter set for the next sub-process area.

2. The welding method for the side beam positioning arm according to claim 1, characterized in that, The preset parameter group of the welding process parameters includes at least one of welding current, arc voltage, welding speed, wire feed speed, the oscillation mode of the welding torch, arc initiation strategy, and arc termination strategy.

3. The welding method for the side beam positioning arm according to claim 1, characterized in that, The area to be welded includes circumferential welds and / or saddle-shaped welds.

4. The welding method for the side beam positioning arm according to claim 1, characterized in that, At least one of the sub-process areas is a weld intersection area, and the other of the sub-process areas is a non-weld intersection area.

5. The welding method for the side beam positioning arm according to claim 4, characterized in that, The welding process parameters corresponding to the weld intersection area are the first welding process parameters. The first welding process parameters include reducing the welding speed and / or changing the oscillation mode of the welding torch to actively control the heat input and solidification behavior of the weld intersection area.

6. The welding method for the side beam positioning arm according to claim 1, characterized in that, Before performing the single-pass continuous automatic welding, the following is also included: A three-dimensional digital model of the side beam positioning arm is performed, and the welding path of the single-pass continuous automatic overlay welding is planned based on the three-dimensional digital model.

7. The welding method for the side beam positioning arm according to claim 6, characterized in that, The welding path is a continuous and smooth trajectory that ensures a smooth transition in the posture of the welding torch.

8. The welding method for the side beam positioning arm according to claim 6, characterized in that, The single-pass continuous automatic welding is performed by an automated workstation consisting of a high-degree-of-freedom welding robot and a positioner.

9. The welding method for the side beam positioning arm according to claim 8, characterized in that, The area to be welded includes a dovetail structure, and the welding method for the side beam positioning arm further includes: When welding the dovetail structure, the high-degree-of-freedom welding robot, combined with attitude calculation technology, dynamically plans and adjusts the attitude of the welding torch in real time to ensure that the welding torch reaches and covers all the surfaces to be welded on the dovetail structure at a preset angle.

10. The welding method for the side beam positioning arm according to claim 9, characterized in that, When welding the dovetail structure, a local protective gas nozzle is used to ensure gas protection of the weld pool within the narrow space of the dovetail structure.

11. The welding method for the side beam positioning arm according to claim 8, characterized in that, The area to be welded includes a stiffener joint, and the welding method for the side beam positioning arm further includes: When welding the stiffener joint, a preset oscillation technique for the welding torch is used, and the centering position and welding angle of the welding torch are controlled to ensure good fusion at the root of the stiffener joint and suppress undercut in the weld toe area.

12. The welding method for the side beam positioning arm according to claim 8, characterized in that, The control system of the high-degree-of-freedom welding robot compares the real-time position coordinates of the welding torch with the preset boundary coordinates of the sub-process area to trigger the switching of welding process parameters.

13. The welding method for a side beam positioning arm according to any one of claims 1 to 12, characterized in that, In the step of performing single-pass continuous automatic surfacing welding, the single-pass continuous automatic surfacing welding forms a single weld on the area to be welded to avoid interlayer lack of fusion or slag inclusion defects caused by multi-pass welding.

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