A welding process for a double-layered profiled metal product

Abstract

The present application relates to the field of metal processing, in particular to a welding process of double-layer special-shaped metal products. It comprises the following steps: S1: stacking positioning and pre-fixing; S2: laser whole-circle welding and multi-parameter collaborative adaptive regulation; S3: welding seam forming detection and post-processing linkage; S4: forming and stress synchronous processing; arc-shaped sandpaper is used to rotate and polish along the arc-shaped transition section, and at the same time, an ultrasonic probe is used to adhere to the laser welding seam through a flexible coupling device to synchronously perform ultrasonic stress relief, so that the integration of welding seam forming and residual stress relief is synchronously completed; S5: finished product detection. Through laser whole-circle welding and multi-parameter collaborative adaptive regulation of the arc-shaped transition section, the welding process of synchronous completion of post-weld polishing and stress relief is realized, the inherent defects of the prior art are solved, and the welding quality and production efficiency are improved.

Description

Technical Field

[0001] This invention relates to the field of metal processing, and more particularly to a welding process for double-layer irregularly shaped metal products. Background Technology Double-layer irregularly shaped metal products are widely used in kitchen and bathroom, containers, mechanical parts and other fields due to their special structure and diverse functions. The core of processing such double-layer irregularly shaped metal products is the lap welding process, which is to weld the upper basin and the lower basin into one piece. The arc-shaped transition section is the key part of the welding and also the weakest part.

[0002] In existing technologies, the lap welding of double-layer irregular metal products mostly adopts traditional fusion welding methods such as argon arc welding and gas shielded welding, which have defects such as large heat input, easy deformation of curved edges and corners, uneven weld width, and obvious stress concentration. With the application of laser welding technology, some processes use laser welding to complete the full-circle sealing welding, but there are still many technical limitations. For example, the prior art with publication number CN118543936B discloses a high-strength welding method for curved surface accessories, which only improves the quality of the curved weld by adjusting the welding current and voltage, without involving laser welding, and without considering the multi-dimensional working condition differences caused by curvature changes and the multi-parameter coordinated control. The prior art with publication number CN114101869B proposes a method for controlling welding parameters in motion, but this method is applicable to oscillating welding of spatial arc-shaped trajectories, is not designed for double-layer irregular structures, and does not involve real-time curvature detection and multi-parameter coordinated linkage.

[0003] When laser welding is performed, a welding path with fixed parameters is used without adaptive parameter control for the curvature changes of the arc transition section. Even if the laser moves along the arc angle trajectory and the distance between the laser spot and the workpiece is consistent, the heat dissipation difference caused by the curvature change, the fluctuation of the overlap gap, and the change of the flow characteristics of the molten pool will lead to defects such as over-melting, undercut, and lack of fusion in the arc transition section, resulting in poor weld formation consistency. Summary of the Invention

[0004] To address the aforementioned problems in existing technologies, this invention provides a welding process for double-layer irregularly shaped metal products. By employing laser full-circle welding and multi-parameter adaptive control of the arc transition section, post-weld grinding and stress relief are simultaneously completed, overcoming the inherent defects of existing technologies and improving welding quality and production efficiency.

[0005] The objective of this invention can be achieved through the following technical solutions: A welding process for double-layer irregularly shaped metal products, used for the overlapping welding of a square arc-shaped upper basin and a trapezoidal square arc-shaped lower basin, includes the following steps: S1: Stacking, Positioning, and Pre-fixing: The square arc transition upper basin is precisely stacked on the trapezoidal square arc transition lower basin, aligning the four arc transition sections of both. The elastic pressure head is then clamped and fixed using hydraulic pressure. Subsequently, a low-current, shallow-melt-nucleus micro-spot welding method is used to spot weld the midpoints of the four straight sides, forming a rigid quadrilateral frame and avoiding the subsequent full-circle welding trajectory. The spot welding current, weld nugget diameter, and weld reinforcement height are controlled within the set range to ensure that the weld points are uniformly melted during subsequent laser welding remelting. S2: Laser full-circle welding and multi-parameter collaborative adaptive control: Laser welding is used to continuously weld the entire circle along the overlapping edge of the upper and lower basins; the straight section is welded using preset conventional laser welding parameters; the arc transition section is welded based on real-time curvature detection and multi-parameter collaborative adaptive control process. S3: Weld formation inspection and post-processing linkage: Visual inspection technology is used to conduct online inspection of laser welds in the arc transition section, identify and record forming defects such as undercut and depressions and their locations; based on the inspection results, the subsequent grinding intensity and ultrasonic stress relief parameters are adjusted to form a closed loop of inspection-post-processing. S4: Simultaneous Forming and Stress Relief: The arc-shaped transition section is polished by rotating the arc-shaped sanding blade to follow the shape. At the same time, the ultrasonic probe is used to fit the laser weld seam through a flexible coupling device to simultaneously perform ultrasonic stress relief, so as to achieve the integrated and simultaneous completion of weld seam forming and residual stress relief. S5: Finished Product Inspection: The surface roughness and residual stress of the treated arc transition section are inspected to ensure that they meet the preset standards, and then the entire welding process is completed.

[0006] In S2, the multi-parameter collaborative adaptive control process specifically includes: Real-time arc curvature detection: A laser contour sensor is used to collect curvature data of the arc transition section in real time. The sampling frequency is not less than 80Hz and the measurement accuracy is better than ±0.02mm. It accurately identifies the curvature increment from the straight edge to the arc angle and feeds the curvature data back to the control system in real time. Multi-parameter collaborative adaptive control: The control system synchronously controls the laser parameters, protective gas parameters, and molten pool compensation parameters based on real-time curvature data to achieve dynamic matching between curvature and each parameter; Real-time monitoring and linkage correction of molten pool: A high-speed vision camera is used to monitor the molten pool shape, and the molten pool width and depth data are fused with the curvature data. When the molten pool shape deviation is detected to exceed the preset threshold, the laser parameters, shielding gas parameters, and molten pool compensation parameters are automatically corrected to form a closed-loop control of "curvature detection - multi-parameter control - molten pool feedback - secondary correction". Preferably, the multi-parameter collaborative adaptive control in step S2 has the following specific parameter linkage logic: S21: Laser parameter control: When the curvature is small, the laser power is 1800-2000W and the welding speed is 500-600mm / min; when the curvature gradually increases and approaches the arc angle, the laser power is simultaneously reduced to 1500-1700W and the welding speed is simultaneously reduced to 350-450mm / min. S22: Shielding gas parameter control: When the curvature is small, the high-purity argon flow rate is 15-18 L / min, and the shielding gas nozzle axis maintains an angle of 30°±5° with the tangent direction of the welding trajectory at the current welding point; when the curvature increases, the argon flow rate increases to 20-22 L / min, and the nozzle angle is finely adjusted in real time with the curvature to dynamically maintain the angle relationship and prevent shielding gas from escaping at the arc corner; S23: Melt pool compensation parameter adjustment: Based on the dynamic gap caused by curvature changes, the laser power and focus position are finely adjusted in a coordinated manner; the dynamic gap is the fitting gap caused by the gradient structure of the trapezoidal lower basin, manufacturing tolerances and transient thermal expansion during welding. When the curvature increases to the area that causes a slight increase in gap, the laser power is increased or the focus offset is adjusted to make the laser beam waist move slightly towards the surface or interior of the workpiece to compensate for insufficient penetration caused by the increase in gap.

[0007] Preferably, in the real-time monitoring and linkage correction of the molten pool, the frame rate of the high-speed vision camera is ≥1000fps, and it has the ability to resist laser arc interference; the preset threshold is: the deviation of the molten pool width exceeds ±0.2mm, or the deviation of the molten pool depth exceeds ±0.1mm; when the above abnormalities are detected, the secondary correction of laser power, protective gas flow rate and focus offset is automatically triggered.

[0008] Preferably, the conventional laser welding parameters used in the straight section in step S2 are: laser power 2000-2200W, defocusing amount +2-+3mm, and high-purity argon gas as the shielding gas.

[0009] Preferably, the laser profile sensor mentioned in step S2 is used to accurately collect curvature change data of the arc transition section, adapting to the arc structure detection requirements of double-layer irregular metal products; the laser profile sensor preferably adopts the Keyence LJ-V7000 series laser profiler, with a measurement accuracy of ±0.01mm and a measurement range of 0-50mm.

[0010] Preferably, the visual inspection technology described in step S3 adopts industrial 3D vision online inspection to adapt to the narrow weld seam characteristics formed by laser welding and accurately identify defects such as undercut, dents, and misalignment.

[0011] Preferably, the forming synchronization process in step S4 involves using a laser contour sensor to collect data on the micro-vibration environment caused by grinding, and feeding this data back to the grinding unit so that it can still maintain constant pressure contact with the weld.

[0012] Preferably, the arc-shaped abrasive sheet in step S4 is a conformal grinding tool that can adapt to the curved surface shape of the arc transition section; the preset standard in step S5 is: the surface roughness Ra of the laser weld seam in the arc transition section is ≤0.8μm, and the weld seam is free of undercut, depression, and microcracks.

[0013] Preferably, it also includes a double-layer irregular metal welding device, applied to the welding process of the aforementioned double-layer irregular metal products, characterized in that: it includes an integrated unit, a grinding unit, a PLC control system, a workpiece, and a liftable processing table and a lifting table; the bottom of the lifting table is provided with a guide rail, the guide rail is aligned with the edge of the square arc transition basin in the workpiece, the integrated unit and the grinding unit are located on the guide rail and electrically connected to the PLC control system, the grinding unit moves with the integrated unit, the liftable processing table also includes a telescopic component, the fixed end of the telescopic component is in contact with the ground and electrically connected to the PLC control system, the telescopic end is slidably connected to the fixed end and connected to the processing table, the lifting table also includes a drive component and an elastic pressure head, one end of the drive component is fixed to the outside and electrically connected to the PLC control system, the lifting table is fixed to one end of the drive component, the lifting table is slidably connected to the processing table, the other end of the drive component is provided with an elastic pressure head, the workpiece is located between the elastic pressure head and the processing table, the PLC control system drives the telescopic component and the drive component in sequence, the telescopic component moves to push the processing table and the lifting table closer, the drive component pushes the elastic pressure head to apply pressure to the workpiece.

[0014] The beneficial effects of this invention are as follows: 1. Solve the problem of poor laser welding of arc transition sections in double-layer irregular metal products: By using multi-parameter collaborative adaptive control based on real-time detection of arc angle curvature, the laser parameters, shielding gas parameters, and molten pool compensation parameters are adjusted to adapt to the differences in heat dissipation, shielding gas coverage, and dynamic gap fluctuations caused by curvature changes, effectively avoiding defects such as over-melting, undercut, lack of fusion, and porosity.

[0015] 2. By constructing a closed-loop system of curvature detection, multi-parameter collaboration, molten pool feedback, and secondary correction, manual intervention parameters are reduced, which can adapt to the arc and trapezoidal composite structures of double-layer irregular basins.

[0016] 3. Laser welding is used to weld the entire circle, resulting in a narrow weld seam and a small heat-affected zone. At the same time, through multi-parameter coordinated control, the advantages of high precision and high efficiency of laser welding are further amplified, expanding the application scenarios of double-layer irregular metal products. Attached Figure Description

[0017] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.

[0018] Figure 1 This is a process step diagram of the present invention; Figure 2 This is a three-dimensional structural diagram of the device of the present invention; Figure 3 This is an exploded view of the device of the present invention; Figure 4 This is a structural diagram of the machined part of the present invention; Figure 5 This is an exploded view of the machined part of the present invention; Figure 6 This is a top view of the present invention; Legend: 1. Placement platform; 11. Limiting strip; 2. Lifting platform; 21. Drive assembly; 22. Elastic pressure head; 3. Processed part; 31. Square arc transition upper basin; 32. Trapezoidal square arc transition lower basin; A. Straight section; B. Arc section; 4. Guide rail; 5. Integrated unit; 6. Grinding unit. Detailed Implementation

[0019] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided.

[0020] refer to Figures 1-6 This embodiment provides a welding process for a double-layer irregularly shaped metal product, used for the overlapping welding of a double-layer irregularly shaped metal product composed of a square arc-shaped transition upper basin 31 and a trapezoidal square arc-shaped transition lower basin. The specific steps are as follows: S1: Stacking and positioning, precisely stack the square arc transition upper basin 31 on the trapezoidal square arc transition lower basin, aligning the four arc transition sections of the two, and using hydraulic means to clamp and fix the elastic pressure head 22, automatically compensating for the height according to the gradient structure of the trapezoidal lower basin, ensuring that the stacked surfaces are tightly fitted throughout, and the fitting effect meets the requirements of subsequent laser welding.

[0021] Secondly, spot welding was performed at the midpoints of the four straight sides using a low-current, shallow-melt-nucleus micro-spot welding method. The spot welding current was set to 90A, with one spot welded on each side (symmetrically arranged in the middle section of the straight side). The spacing between the spot welds was adapted to the length of the straight side. In addition, the spot welds were placed 15mm away from the overlapping edge in the middle section of the straight side to avoid the subsequent laser full-circle welding trajectory. After spot welding was completed, the surface of the spot welds was inspected. There were no protruding weld beads, and the welds were basically flush with the base material. The rigid quadrilateral frame was well formed, and the stacking position was not displaced, meeting the positioning requirements for subsequent laser full-circle welding.

[0022] S2: Laser circumferential welding is performed using a fiber laser welding machine with a power of at least 3000W, continuously welding the entire circumference along the overlapping edge of the upper and lower basins. The straight section A uses conventional laser welding parameters set as follows: laser power 2100W, defocusing amount +2.5mm, high-purity argon gas flow rate 16L / min, and welding speed 550mm / min. The curved transition section employs a multi-parameter collaborative adaptive control process based on real-time detection of the arc angle curvature, as detailed below: (1) Real-time detection of arc angle curvature: A laser profile sensor is used and installed on the side of the laser welding head. It moves synchronously with the welding head. The laser profile sensor preferably uses the Keyence LJ-V7000 series laser profiler, with a measurement accuracy of ±0.01mm and a measurement range of 0-50mm. The sampling frequency is set between 80Hz and 100Hz, with a measurement accuracy of ±0.02mm. The curvature data of the arc transition section is collected in real time, and the curvature change from the straight edge to the arc angle is identified. The curvature data is fed back to the PLC control system in real time. The PLC control system has a built-in curvature data parameter table that is preset to meet the processing conditions of the workpiece and has a built-in threshold line to determine the curvature size threshold range. The curvature changes from small to large from straight segment to arc segment to straight segment. In addition, it also includes a laser power parameter table, a protective gas parameter table, and a molten pool compensation parameter table. All of the above parameter tables form a one-to-one mapping relationship with the calibrated curvature values. All of the above parameter tables can be established as the optimal parameter table through experimental verification. (2) The PLC control system adjusts synchronously based on the above parameter table according to the real-time curvature data; First: Laser parameters: When the curvature is close to the straight side and the curvature is small, the laser power is set to 1900W and the welding speed is set to 550mm / min; When the curvature is close to the arc angle and the curvature is large, the laser power is reduced to 1600W and the welding speed is reduced to 400mm / min. The power is reduced synchronously and the welding speed is slowed down as the curvature increases; Second: Shielding gas parameters: When the curvature is small, the high-purity argon gas flow rate is set to 16L / min and the angle between the shielding gas nozzle and the welding tangent is 30°; When the curvature is large, the argon gas flow rate is increased to 21L / min and the nozzle angle is adjusted in real time according to the curvature. It always maintains an angle of 30°±2° with the arc tangent to ensure that the shielding gas covers the arc corner completely and there is no escape. (2) Melt pool compensation parameters: When the curvature increases, the overlap gap increases slightly. The control system automatically adjusts the laser focus offset towards the workpiece to compensate for the insufficient penetration caused by the slight increase in the gap, and ensures consistent penetration.

[0023] (3) Real-time monitoring and linkage correction of molten pool: A high-speed vision camera with a frame rate of 1200fps is installed on the other side of the laser welding head to collect molten pool width and depth data in real time. When the molten pool width deviation at the arc corner position is detected to reach over-melting, the control system automatically reduces the laser power to 1550W, increases the argon flow rate to 22L / min, and fine-tunes the focus offset until the molten pool shape returns to normal, forming a closed-loop correction.

[0024] S3: Weld formation inspection. Industrial 3D vision online inspection equipment is used to inspect the laser welds of four arc transition sections online. It is adapted to the characteristics of narrow laser welds and accurately identifies whether there are defects such as undercut, depression, and misalignment in the weld. After inspection, if a slight depression is found in any arc transition section, the location and degree of the defect are recorded and the subsequent grinding intensity is automatically adjusted.

[0025] S4: Synchronous forming process. Based on the test results, the grinding intensity is adjusted to medium strength. A POLIFAN-CURVE type multi-blade, arc-shaped abrasive disc is used to rotate and grind the arc-shaped transition section, with the grinding direction consistent with the arc trajectory. The arc-shaped abrasive disc is designed to fit the curved surface shape of the arc-shaped transition section. A laser contour sensor collects the micro-vibration caused by grinding and feeds it back to grinding unit 6 to maintain constant pressure contact with the weld. After grinding, minor depressions are eliminated, and the arc transition is smooth.

[0026] S5: Finished product inspection, surface roughness inspection of the four arc transition sections; the inspection results must meet the preset standards; if the conditions are met, the weld must be free of defects such as undercut, depression, microcracks, and porosity, the arc transition must be smooth and natural, and there must be no step when connecting with the base material, thus completing the entire welding process.

[0027] In response, the process method of this embodiment solves the problems of forming defects and uneven shielding gas coverage in the arc transition section of double-layer irregular metal products by integrating laser full-circle welding, multi-parameter collaborative adaptive control of arc transition section, and post-weld forming and stress synchronous treatment. This results in stable welding quality, high production efficiency, and is suitable for the large-scale production of double-layer irregular metal products.

[0028] To achieve the above process requirements, a double-layer irregular metal welding device is also included, comprising an integrated unit 5, a grinding unit 6, a PLC control system, a workpiece 3, and a liftable processing table and a lifting table 2. The liftable processing table also includes a telescopic component, the fixed end of which contacts the ground and is electrically connected to the PLC control system, and the telescopic end slides onto the fixed end and is connected to the processing table. The lifting table 2 also includes a drive assembly 21 and an elastic pressure head 22. One end of the drive assembly 21 is fixed externally and electrically connected to the PLC control system, and the lifting table 2 is fixed to one end of the drive assembly 21. The lifting table 2 slides onto the processing table, and the other end of the drive assembly 21 is provided with an elastic pressure head 22. The workpiece 3 is located between the elastic pressure head 22 and the processing table. The PLC control system drives the telescopic component and the drive assembly 21 in sequence. The telescopic component's telescopic movement pushes the processing table closer to the lifting table 2, and the drive assembly 21 pushes the elastic pressure head 22 to apply pressure to the workpiece 3. Therefore, both the telescopic component and the drive assembly 21 can be hydraulic cylinders. The telescopic component drives the processing table and the lifting platform 2 to maintain a minimum sliding stroke, thereby reducing the distance between them and facilitating subsequent compact processing. At the same time, the distance between them can be changed, which also facilitates subsequent placement and removal. In addition, the drive assembly 21 drives the elastic pressure head 22 to contact and press against the top of the workpiece 3, improving the stability of the workpiece 3 during the processing. This makes it convenient to pick up and put down the workpiece 3 and maintain sufficient stability for processing.

[0029] Specifically, the workpiece 3 consists of a square arc-shaped transition upper basin 31 and a trapezoidal square arc-shaped transition lower basin 32. The upper part of the workpiece 3 has a square arc-shaped edge structure and also includes limiting strips 11. The worktable is provided with several limiting strips 11, which are connected in sequence to form a "U"-shaped structure. The limiting strips 11 respectively limit the three edges of the workpiece 3 with the square arc-shaped edge structure. The other side is missing a limiting strip 11, which facilitates the movement, placement and removal of the workpiece 3.

[0030] Specifically, the square arc transition basin 31 has a straight segment A and an arc segment B, which are connected end to end. The arc end is located at the corner of the square arc transition basin 31, and the straight segment A is located in the middle section. It should also be noted that in the welding process of double-layer irregular metal products, the midpoint of the straight segment A is the fixed welding point.

[0031] Specifically, integrated unit 5 includes a fiber laser welding machine, a laser profile sensor, a high-speed vision camera, and an industrial 3D vision online inspection device. The fiber laser welding machine is located in the middle, the laser profile sensor and the high-speed vision camera are located on either side of the fiber laser welding machine, and the industrial 3D vision online inspection device is located below the fiber laser welding machine.

[0032] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A welding process for double-layer irregularly shaped metal products, used for the overlapping welding process of a square arc-shaped transition upper basin and a trapezoidal square arc-shaped transition lower basin, characterized in that, Includes the following steps: S1: Stacking Positioning and Pre-fixing: The square arc transition upper basin is stacked on the trapezoidal square arc transition lower basin. An adaptive positioning fixture is used to align the four arc transition sections of the two basins one by one. The elastic pressure head is clamped and fixed by hydraulic means. Then, a low current shallow weld nugget micro-spot welding method is used to spot weld the midpoints of the four straight sides to form a rigid quadrilateral frame and avoid the subsequent full-circle welding trajectory. The spot welding current, weld nugget diameter, and weld remnant height are controlled within the set range to ensure that the weld nugget can be uniformly melted during the subsequent laser welding remelting. S2: Laser full-circle welding and multi-parameter collaborative adaptive control: Laser welding is used to continuously weld the entire circle along the overlapping edge of the upper and lower basins; the straight section is welded using preset conventional laser welding parameters; the arc transition section is welded based on real-time curvature detection and multi-parameter collaborative adaptive control process. S3: Weld formation inspection and post-processing linkage: Visual inspection technology is used to conduct online inspection of laser welds in the arc transition section, identify and record weld undercut, depression forming defects and their locations; based on the inspection results, the subsequent grinding intensity and ultrasonic stress relief parameters are adjusted to form a closed loop of inspection-post-processing. S4: Simultaneous forming process: The arc-shaped transition section is polished by rotating the arc-shaped sander to follow the shape. S5: Finished product inspection: The surface roughness of the processed arc transition section is inspected to ensure that it meets the preset standards, and then the entire welding process is completed. In S2, the multi-parameter collaborative adaptive control process specifically includes: using a laser contour sensor to collect curvature data of the arc transition section in real time, accurately identifying the curvature increment rate from the straight edge to the arc angle, and feeding the curvature data back to the control system in real time; the control system synchronously controls the laser parameters, shielding gas parameters, and molten pool compensation parameters according to the real-time curvature data to achieve dynamic matching between curvature and each parameter; and using a high-speed vision camera to monitor the molten pool morphology, fusing the molten pool width and depth data with the curvature data, and automatically correcting the laser parameters, shielding gas parameters, and molten pool compensation parameters when the molten pool morphology deviation exceeds a preset threshold, forming a closed-loop control of curvature detection - multi-parameter control - molten pool feedback - secondary correction.

2. The welding process for double-layer irregularly shaped metal products according to claim 1, characterized in that, The multi-parameter collaborative adaptive control process described in step S2 has the following specific parameter linkage logic: S21: Laser parameter control: When the curvature is small, the laser power is 1800-2000W and the welding speed is 500-600mm / min; when the curvature gradually increases and approaches the arc angle, the laser power is simultaneously reduced to 1500-1700W and the welding speed is simultaneously reduced to 350-450mm / min. S22: Shielding gas parameter control: When the curvature is small, the high-purity argon flow rate is 15-18 L / min, and the shielding gas nozzle axis maintains an angle of 30°±5° with the tangent direction of the welding trajectory at the current welding point; when the curvature increases, the argon flow rate is increased to 20-22 L / min, and the nozzle angle is finely adjusted in real time with the curvature to dynamically maintain the angle relationship and prevent shielding gas from escaping at the arc corner; S23: Molten pool compensation parameter adjustment: Based on the dynamic gap caused by curvature changes, the laser power and focus position are finely adjusted in a coordinated manner; The dynamic gap is the fit gap caused by the gradient structure of the trapezoidal lower basin, manufacturing tolerances, and transient thermal expansion during welding. When the curvature increases to the area that causes a slight increase in gap, the laser power is increased or the focus offset is adjusted to make the laser beam waist move slightly towards the surface or interior of the workpiece to compensate for the insufficient penetration caused by the increased gap.

3. The welding process for double-layer irregularly shaped metal products according to claim 2, characterized in that, In the real-time monitoring and linkage correction of the molten pool, the frame rate of the high-speed vision camera is ≥1000fps and has the ability to resist laser arc interference; the preset threshold is: the deviation of the molten pool width exceeds ±0.2mm, or the deviation of the molten pool depth exceeds ±0.1mm; when the above abnormalities are detected, the secondary correction of laser power, protective gas flow rate and focus offset is automatically triggered.

4. The welding process for double-layer irregularly shaped metal products according to claim 1, characterized in that, The conventional laser welding parameters used in the straight section in step S2 are: laser power 2000-2200W, defocusing amount +2-+3mm, and high-purity argon gas as the shielding gas.

5. The welding process for double-layer irregularly shaped metal products according to claim 1, characterized in that, The laser contour sensor mentioned in step S2 is installed on the side of the laser welding head and moves synchronously with the welding head. It is used to accurately collect the curvature change data of the arc transition section and adapt to the arc structure detection requirements of double-layer irregular metal products.

6. The welding process for double-layer irregularly shaped metal products according to claim 1, characterized in that, The visual inspection technology described in step S3 uses industrial 3D vision online inspection to adapt to the narrow weld seam characteristics formed by laser welding and accurately identify defects such as undercut, dents, and misalignment.

7. The welding process for double-layer irregularly shaped metal products according to claim 5, characterized in that, The forming synchronization process described in step S4 involves collecting the micro-vibration environment caused by grinding through a laser contour sensor and feeding it back to the grinding unit so that it can still maintain constant pressure contact with the weld.

8. The welding process for double-layer irregularly shaped metal products according to claim 1, characterized in that, The arc-shaped abrasive disc mentioned in step S4 is a grinding tool that can adapt to the curved surface shape of the arc transition section.

9. A double-layer irregular metal welding apparatus, used in the welding process of double-layer irregular metal products according to any one of claims 1-8, characterized in that: The system includes an integrated unit, a grinding unit, a PLC control system, a workpiece, and a height-adjustable processing table and a lifting platform. The bottom of the lifting platform has a guide rail that tracks the same path as the edge of the square arc transition basin in the workpiece. The integrated unit and the grinding unit are mounted on the guide rail and electrically connected to the PLC control system. The grinding unit moves with the integrated unit. The height-adjustable processing table also includes a telescopic component. The fixed end of the telescopic component contacts the ground and is electrically connected to the PLC control system, while the telescopic end slides onto the fixed end and connects to the processing table. The lifting platform also includes a drive assembly and an elastic pressure head. One end of the drive assembly is fixed externally and electrically connected to the PLC control system. The lifting platform is fixed to one end of the drive assembly and slides onto the processing table. The other end of the drive assembly has a telescopic elastic pressure head. The workpiece is positioned between the elastic pressure head and the processing table. The PLC control system sequentially drives the telescopic component and the drive assembly. The telescopic component's telescopic movement pushes the processing table closer to the lifting platform, and the drive assembly pushes the elastic pressure head to apply pressure to the workpiece.

Images