A laser welding and on-line inspection integrated device and method for a battery tray frame

Abstract

This invention discloses an integrated laser welding and online inspection device and method for battery tray frames. It integrates a laser welding unit, an online inspection unit, a central control system, a marking device, and a sorting device onto a single device, achieving integrated processing of the entire battery tray frame process from pre-welding cleaning, laser welding, online inspection, to product sorting. This eliminates the inefficiency caused by the separation of welding and inspection processes in traditional methods. Downstream of the laser welding unit, an eddy current testing device, an ultrasonic testing device, and a visual inspection device are sequentially installed to detect internal defects, near-surface defects, surface defects, and internal defects in the weld, respectively. This forms a comprehensive inspection system from the inside out and from deep to shallow, providing wide coverage and high accuracy. The central control system interacts with the laser welding unit and the online inspection unit in real time.

Description

Technical Field

[0001] This invention relates to the field of battery tray processing technology, specifically to an integrated laser welding and online inspection device for battery tray frames. Background Technology

[0002] Battery trays (also known as battery boxes or battery brackets) are the main load-bearing components of power batteries in new energy vehicles, requiring extremely high load-bearing capacity, sealing performance, and assemblability. As the core structural component of the battery tray, the battery tray frame is typically constructed from aluminum alloy profiles or steel plates through welding. The welding quality directly affects the overall structural strength, sealing performance, and safety of the battery tray. In recent years, with the rapid development of the new energy vehicle industry, the market size of battery trays has continued to grow rapidly, and the industry has placed increasingly higher demands on the efficiency, quality, and cost control of battery tray welding.

[0003] Currently, the welding of battery tray frames mainly employs traditional arc welding, resistance spot welding, or stamping welding. However, these traditional welding technologies have revealed numerous insurmountable technical problems in long-term production practice, as detailed below: First, the welding speed is slow, resulting in low production efficiency. Traditional arc welding and resistance spot welding are typically slow, generally only 1.5–3.5 meters per minute. Taking stamping welding as an example, under traditional stamping welding methods, three workers can only complete the welding of approximately 150 battery tray frames per hour, with an average output of only 50 pieces per hour, resulting in extremely limited production efficiency. Against the backdrop of continuously increasing production of new energy vehicles, this inefficient welding method has become a bottleneck restricting the improvement of battery tray production capacity.

[0004] Secondly, the welding deformation is significant, leading to heavy subsequent processing work. Traditional arc welding is a fusion welding process with a large heat input and a wide heat-affected zone, easily causing significant thermal deformation of the workpiece. Battery tray frames are typically thin-walled profile structures, making them particularly sensitive to thermal deformation. Under traditional welding methods, the weld seam accuracy can usually only reach ≥0.5mm, resulting in significant overall deformation of the frame after welding. This necessitates extensive grinding, shaping, and other subsequent processing to meet assembly accuracy requirements, increasing processing costs and extending the production cycle.

[0005] Third, the detection of welding defects is seriously lagging behind, making real-time monitoring impossible. In the traditional production of battery tray frames, the detection of welding quality mainly adopts offline sampling inspection, that is, after welding is completed, the product is taken off the production line and sent to a special testing laboratory for destructive or non-destructive testing. This inspection method has the following serious defects: (1) The test results lag behind the production process and cannot detect defects such as weak welds, false welds, overheating, cracks, and incomplete penetration that occur during the welding process in a timely manner; (2) Sampling inspection cannot cover every product, and there is a risk of missed inspection. Unqualified products may flow into subsequent processes or even the final assembly stage, causing serious safety hazards and economic losses; (3) Once a batch of welding quality problems are found, a large number of unqualified products that have been generated need to be reworked or scrapped, resulting in huge material waste and cost losses.

[0006] Fourth, the low precision of weld joint quality inspection makes it difficult to accurately determine internal defects. Current technologies primarily rely on manual visual inspection or simple instrument testing for weld joint quality inspection. Manual visual inspection can only detect macroscopic defects on the weld surface (such as surface cracks, porosity, and undercut), and cannot determine whether the weld penetration is sufficient, or whether there are hidden defects such as incomplete penetration or internal porosity. Even with simple testing instruments, the limitations of the testing principles often make it difficult to accurately assess the internal quality of the weld joint. This low-precision inspection method cannot meet the high reliability requirements of battery tray welding quality.

[0007] Fifth, the welding and inspection processes are separated, resulting in a disjointed production flow. In traditional production models, welding and inspection processes are typically completed at different workstations or even in different workshops. Products must be transferred after welding before entering the inspection stage. This separation of processes not only increases logistics and transportation costs but also prevents the formation of an effective closed-loop control between welding and inspection. Welding parameters cannot be adjusted in real time based on inspection results, and improvements in welding quality rely on post-processing analysis, leading to slow response times and low efficiency.

[0008] In summary, existing battery tray frame welding technologies suffer from multiple problems, including low welding efficiency, large deformation, delayed detection, low detection accuracy, and process separation. There is an urgent need for an integrated device that can organically combine high-efficiency laser welding with online real-time detection to achieve efficient, high-quality, and high-reliability welding of battery tray frames. Summary of the Invention

[0009] To solve the above-mentioned technical problems, the present invention provides an integrated laser welding and online inspection equipment for battery tray frames, including a frame for supporting and installing various functional units; A conveying device, which is mounted on the frame, is used to convey battery tray frame workpieces along a predetermined direction; A laser welding unit is provided on the frame and located above or to the side of the conveying device, for laser welding of the battery tray frame workpiece conveyed by the conveying device; An online inspection unit is provided, which is mounted on the frame and located downstream of the laser welding unit, and is used to perform online real-time inspection of the weld after it has been welded by the laser welding unit. The central control system is communicatively connected to both the laser welding unit and the online detection unit. It receives detection data from the online detection unit and sends welding parameter adjustment instructions to the laser welding unit based on the detection data.

[0010] Preferably, the laser welding unit includes a laser, a laser welding head, a laser welding head drive mechanism, and a shielding gas supply device. The laser is a fiber laser or a disk laser; the laser welding head is mounted at the end of the laser welding head drive mechanism, which is a multi-axis robot or a three-dimensional motion platform, used to drive the laser welding head to move in three-dimensional space to align with the weld seam; the shielding gas supply device is used to provide shielding gas to the welding area during the welding process.

[0011] Preferably, the online inspection unit includes an eddy current testing device, which is positioned above the conveying device downstream of the laser welding unit and used to perform eddy current testing on the weld after welding. The eddy current testing device includes an eddy current probe, an eddy current signal generator, and an eddy current signal analyzer. During testing, the eddy current probe maintains a distance of 0.5–3 mm from the weld surface. The eddy current signal generator provides an excitation signal with a frequency of 10 kHz–10 MHz to the eddy current probe. The eddy current signal analyzer receives and analyzes the eddy current feedback signal collected by the eddy current probe and determines whether there are defects such as cracks, incomplete penetration, or porosity inside the weld based on the eddy current feedback signal. The detection accuracy of the eddy current testing device can reach 0.1 mm, effectively identifying minute defects inside the weld.

[0012] Preferably, the online inspection unit further includes an ultrasonic inspection device, which is located above the conveying device downstream of the eddy current flaw detector and is used to perform ultrasonic inspection on the weld. The ultrasonic inspection device includes an ultrasonic probe, an ultrasonic signal generator, and an ultrasonic signal analyzer. A coupling medium (such as water or a coupling agent) is provided between the ultrasonic probe and the weld surface. The ultrasonic signal generator provides an excitation signal to the ultrasonic probe. The ultrasonic probe emits ultrasonic waves towards the weld and receives reflected waves. The ultrasonic signal analyzer determines whether there are defects inside the weld based on the received reflected wave signal. The ultrasonic inspection device uses ultrasonic TOFD (Time-of-Flight Diffraction) technology for signal acquisition and can detect defects such as porosity, slag inclusions, and lack of fusion near the weld surface and inside the weld.

[0013] Preferably, the online inspection unit further includes a visual inspection device, which is positioned above the conveying device downstream of the ultrasonic inspection device and is used to visually inspect the surface quality of the weld. The visual inspection device includes an industrial camera, a light source, and an image processor; the industrial camera is a CCD or CMOS camera used to acquire images of the weld surface; the light source is an LED or laser light source used to provide illumination for the industrial camera; and the image processor is used to process and analyze the acquired weld images, identify surface defects such as cracks, porosity, undercut, and incomplete filling, and measure geometric parameters such as the weld width, height, and weld width.

[0014] Preferably, the central control system includes a data acquisition module, a data analysis module, and a control command output module. The data acquisition module is used to acquire the detection data output by the online detection unit in real time; the data analysis module is used to analyze and process the detection data to determine whether the weld quality is qualified, and to determine the type and severity of defects when weld defects are detected; the control command output module is used to send welding parameter adjustment commands to the laser welding unit based on the analysis results of the data analysis module; the welding parameter adjustment commands include one or more of the following: laser power adjustment command, welding speed adjustment command, defocusing amount adjustment command, and shielding gas flow rate adjustment command.

[0015] Preferably, the device further includes a welding parameter database, which is communicatively connected to the central control system and stores standard welding parameters and defect correction parameters corresponding to different battery tray frame models, different material types, and different weld forms. When the online detection unit detects a weld defect, the central control system retrieves the corresponding defect correction parameters from the welding parameter database and sends a welding parameter adjustment command to the laser welding unit accordingly.

[0016] Preferably, the conveying device is a roller conveyor, a plate chain conveyor, or a belt conveyor. The conveying speed of the conveying device is matched with the welding speed of the laser welding unit, and the conveying speed is 2 to 20 meters per minute; preferably, the conveying speed of the conveying device is 18 meters per minute.

[0017] Preferably, the device further includes a workpiece positioning fixture, which is disposed on the conveying device and is used to position and clamp the battery tray frame workpiece; the workpiece positioning fixture includes a positioning pin, a clamping cylinder and a pressing block, the positioning pin is used to cooperate with the positioning hole on the workpiece to achieve precise positioning, and the clamping cylinder drives the pressing block to press the workpiece onto the conveying device.

[0018] The equipment further includes a pre-welding cleaning device, which is located above the conveying device upstream of the laser welding unit and is used to clean the area to be welded on the battery tray frame workpiece before welding; the pre-welding cleaning device is one of a laser cleaning device, a plasma cleaning device, or a mechanical brushing device.

[0019] Preferably, the equipment further includes a marking device, which is disposed above the conveying device downstream of the online detection unit and is used to mark the qualified battery tray frames; the marking device is a laser marking machine or an inkjet printer.

[0020] Preferably, the equipment further includes a sorting device, which is located on one side of the conveying device downstream of the online detection unit, and is used to separate qualified products and unqualified products according to the detection results of the online detection unit; the sorting device includes a pushing cylinder, a guide plate and a collection box, and the pushing cylinder is used to push unqualified products from the conveying device into the collection box.

[0021] Preferably, the laser welding unit includes a weld seam tracking device, which is used to detect the actual position of the weld seam in real time during the welding process and feed back the position deviation signal to the central control system. The central control system controls the laser welding head drive mechanism to adjust the position of the laser welding head according to the position deviation signal to achieve precise weld seam tracking. The weld seam tracking device is a laser vision sensor or a mechanical contact sensor.

[0022] Preferably, the device further includes a cooling device for cooling the laser welding unit and / or the online detection unit; the cooling device is a water-cooling device or an air-cooling device.

[0023] A method for laser welding and online inspection of a battery tray frame, using the integrated laser welding and online inspection equipment for the battery tray frame described in any one of the above claims, includes the following steps: Step S1: Workpiece loading and positioning: Place the battery tray frame workpiece on the conveying device, and position and clamp the workpiece using the workpiece positioning fixture; Step S2: Pre-welding cleaning: The pre-welding cleaning device is used to clean the area of ​​the workpiece to be welded, removing oil, dust and oxide layer; Step S3: Laser welding: Start the laser welding unit and perform laser welding on the area to be welded of the workpiece according to the preset welding parameters; during the welding process, the weld seam tracking device monitors the actual position of the weld seam in real time, and the central control system adjusts the position of the laser welding head according to the position deviation signal; Step S4: Online inspection: After welding, the workpiece moves with the conveying device to the bottom of the online inspection unit and passes through the eddy current flaw detection device, the ultrasonic detection device and the visual inspection device in sequence to inspect the internal defects, near-surface defects and surface quality of the weld. Step S5: Data Feedback and Parameter Adjustment: The online detection unit transmits the detection data to the central control system, which analyzes and processes the data. When a weld defect is detected, the central control system retrieves the corresponding defect correction parameters from the welding parameter database according to the defect type and severity, and sends a welding parameter adjustment command to the laser welding unit. Step S6: Product marking and sorting: The marking device marks the qualified workpieces, and the sorting device separates qualified and unqualified products according to the test results.

[0024] Preferably, in step S3, the welding speed of the laser welding unit is 2 to 20 meters per minute, more preferably 8 to 18 meters per minute; the laser power is 1000W to 8000W; the defocusing amount is -5mm to +5mm; and the protective gas flow rate is 5 to 25L / min.

[0025] Preferably, in step S4, the eddy current flaw detection device has a detection accuracy of 0.1 mm and the detection speed is synchronized with the welding speed.

[0026] The technical effects and advantages of this invention are as follows: 1. The laser welding unit of this invention uses a high-power fiber laser or disk laser, achieving a welding speed of 8-18 meters per minute, which is more than three times that of traditional stamping welding (approximately 2-3.5 meters per minute). Taking a specific embodiment of this invention as an example, using the Prima five-axis three-dimensional laser processing system, one operator can complete the welding of 120 battery tray frames per hour, while three operators can only complete 150 pieces per hour using the traditional stamping welding method, resulting in a 60% increase in efficiency per operator. Furthermore, this invention integrates welding and inspection into the same production line, eliminating the time spent transferring workpieces between different processes in the traditional model, further improving overall production efficiency.

[0027] 2. This invention utilizes laser welding technology, which features high laser beam energy density, low heat input, and a narrow heat-affected zone, resulting in minimal thermal deformation of the workpiece during welding. Testing shows that using this invention for battery tray frame welding achieves weld seams controlled to ≤0.3mm, significantly superior to the ≥0.5mm of traditional welding. The overall surface profile of the welded frame is ≤2.0mm, fully meeting high-precision assembly requirements. Due to the substantial reduction in welding deformation, subsequent grinding work is reduced by approximately 80%, significantly lowering subsequent processing costs and time.

[0028] 3. This invention sequentially incorporates an eddy current testing device, an ultrasonic testing device, and a visual inspection device downstream of the laser welding unit, enabling multi-level, all-round online real-time detection of internal weld defects, near-surface defects, and surface quality. The eddy current testing device effectively detects internal weld defects such as cracks and incomplete penetration, with a detection accuracy of up to 0.1 mm. The ultrasonic testing device, employing TOFD technology, detects near-surface and internal weld defects such as porosity, slag inclusions, and lack of fusion. The visual inspection device identifies surface defects such as cracks, porosity, and undercut, and measures weld geometric parameters. This triple-detection approach achieves comprehensive monitoring of welding quality. Once a defect is detected, non-conforming products are immediately identified and diverted, preventing them from flowing into subsequent processes. Practical application verification shows that the product qualification rate increased from the traditional 95% to 99.5% after adopting this invention.

[0029] 4. The central control system of this invention interacts with the laser welding unit and the online detection unit in real time, forming a closed-loop control circuit of "welding-detection-feedback-adjustment". When the online detection unit detects a weld defect (such as incomplete penetration), the central control system can automatically send welding parameter adjustment instructions (such as increasing laser power, decreasing welding speed, etc.) to the laser welding unit according to the defect type and severity. This allows for timely correction of process parameters in subsequent welding processes, preventing the recurrence of similar defects. This adaptive adjustment mechanism continuously optimizes welding quality and reduces the production of defective products.

[0030] 5. This invention utilizes laser welding, eliminating the need for blanking dies, punching dies, trimming dies, and other molds, saving nearly ten million yuan annually in mold development costs. Secondly, because it enables online real-time inspection, it eliminates the need for dedicated offline inspection personnel, reducing labor costs. Thirdly, by increasing the product qualification rate from 95% to 99.5%, the rework and scrap costs of defective products are significantly reduced, and material utilization is significantly improved.

[0031] 6. This invention integrates multiple functional units such as laser welding, online inspection, marking, and sorting onto the same production line, forming an integrated processing equipment. Compared to traditional decentralized production lines (where welding workshops, inspection workshops, grinding workshops, etc., are separate), this invention reduces the site area required by approximately 80%, which has significant economic implications in today's increasingly land-scarce environment.

[0032] 7. The integrated design of this invention allows all processes of the battery tray frame, from pre-welding cleaning, laser welding, online inspection to marking and sorting, to be completed continuously on the same equipment. This results in a highly streamlined production process without the need for manual intervention or material transfer. This not only reduces management steps and costs but also enhances the traceability of the production process, facilitating quality management and continuous improvement. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the integrated laser welding and online inspection equipment for the battery tray frame provided in this application embodiment; Figure 2 This is a schematic diagram of the structure of the laser welding unit in the integrated laser welding and online inspection equipment for the battery tray frame provided in this application embodiment; Figure 3 This is a schematic diagram of the online inspection unit in the integrated laser welding and online inspection equipment for the battery tray frame provided in this application embodiment; Figure 4 This is a schematic diagram of the central control system of the integrated laser welding and online inspection equipment for the battery tray frame provided in this application embodiment; Figure 5 This is a schematic diagram of the workpiece positioning fixture structure of the integrated laser welding and online inspection equipment for the battery tray frame provided in this application embodiment; Figure 6 This is a schematic diagram of the sorting device in the integrated laser welding and online inspection equipment for battery tray frames provided in this application embodiment; Figure 7 This is a flowchart of the laser welding and online inspection method for the battery tray frame provided in the embodiments of this application.

[0034] In the diagram: 1—Frame; 2—Conveying device; 3—Laser welding unit; 31—Laser; 32—Laser welding head; 33—Laser welding head drive mechanism; 34—Shielding gas supply device; 35—Weld tracking device; 4—Online inspection unit; 41—Eddy current flaw detection device; 411—Eddy current probe; 412—Eddy current signal generator; 413—Eddy current signal analyzer; 42—Ultrasonic inspection device; 421—Ultrasonic probe; 422—Ultrasonic signal generator; 423—Ultrasonic signal analyzer; 43—Visual inspection device. Measurement device; 431—Industrial camera; 432—Light source; 433—Image processor; 5—Central control system; 51—Data acquisition module; 52—Data analysis module; 53—Control command output module; 6—Welding parameter database; 7—Workpiece positioning fixture; 71—Positioning pin; 72—Clamping cylinder; 73—Pressure block; 8—Pre-welding cleaning device; 9—Marking device; 10—Sorting device; 101—Pushing cylinder; 102—Guide plate; 103—Collection box; 11—Cooling device; 12—Battery tray frame workpiece. Detailed Implementation

[0035] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0036] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0037] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a signal connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0038] Example 1 like Figure 1 and Figure 2As shown, this embodiment provides an integrated laser welding and online inspection equipment for battery tray frames, including a frame 1, a conveying device 2, a laser welding unit 3, an online inspection unit 4, and a central control system 5.

[0039] The frame 1 serves as the basic load-bearing structure of the equipment of this invention. It is welded from high-strength steel and possesses sufficient rigidity and stability. The upper surface of the frame 1 is a horizontal mounting surface for mounting the conveying device 2 and other functional units. The bottom of the frame 1 is equipped with adjustable feet to adjust the level and height of the frame 1 to adapt to different installation site conditions.

[0040] Conveying device 2 is mounted on frame 1 and is used to convey battery tray frame workpiece 12 along a predetermined direction. In this embodiment, conveying device 2 is a roller conveyor line, including multiple parallel conveyor rollers and drive motors that drive the conveyor rollers to rotate. The surface of the conveyor rollers is provided with anti-slip patterns to prevent the workpiece from slipping during conveying. The drive motor is a variable frequency speed control motor, which drives each conveyor roller to rotate synchronously via a chain or belt. The conveying speed of conveying device 2 can be steplessly adjusted according to the welding speed of laser welding unit 3, with an adjustment range of 2 to 20 meters per minute. In this embodiment, the preferred conveying speed is 18 meters per minute.

[0041] In other embodiments, the conveying device 2 may also be a plate chain conveyor or a belt conveyor. Plate chain conveyors are suitable for conveying heavy workpieces and have the advantages of high load-bearing capacity and stable operation; belt conveyors are suitable for conveying light workpieces and have the advantages of simple structure and low cost.

[0042] The laser welding unit 3 is mounted on the frame 1 and located above the conveying device 2, and is used to perform laser welding on the battery tray frame workpiece 12 conveyed by the conveying device 2. The laser welding unit 3 includes a laser 31, a laser welding head 32, a laser welding head drive mechanism 33, and a protective gas supply device 34.

[0043] Laser 31 is a high-power fiber laser with a rated output power of 6000W, an output laser wavelength of 1070nm, and a beam quality M²≤1.2. Laser 31 is connected to laser welding head 32 via optical fiber, transmitting laser energy to laser welding head 32. In other embodiments, laser 31 can also be a disk laser or a CO2 laser, with a laser power range of 1000W to 8000W. The specific power selection is determined based on process parameters such as workpiece material, thickness, and welding speed.

[0044] The laser welding head 32 is mounted at the end of the laser welding head drive mechanism 33. The laser welding head 32 internally houses a collimating lens, a focusing lens, and a protective lens, used to collimate and focus the laser beam transmitted from the optical fiber, forming a high-energy-density laser spot that acts on the workpiece surface. The laser welding head 32 also includes a focal point adjustment mechanism for adjusting the defocus amount of the laser spot, with an adjustment range of -5mm to +5mm. In this embodiment, when welding an aluminum alloy battery tray frame, a defocus amount of +1 to +3mm is preferred.

[0045] The laser welding head drive mechanism 33 is a six-axis industrial robot with six degrees of freedom, capable of flexibly moving the laser welding head 32 in three-dimensional space to achieve precise tracking and welding of complex-shaped welds. The repeatability of the six-axis industrial robot is ≤±0.05mm, ensuring the accuracy of the welding position. In other embodiments, the laser welding head drive mechanism 33 can also be a gantry-type three-dimensional motion platform or a Cartesian coordinate robot.

[0046] The protective gas supply device 34 includes a gas source, a gas pipeline, and a gas nozzle. The gas source is a high-purity argon cylinder or argon supply pipeline, providing argon gas with a purity ≥99.99% as the protective gas. The gas pipeline connects the gas source to the gas nozzle and is equipped with a gas flow regulating valve and a gas pressure gauge for precise control of the flow rate and pressure of the protective gas. The gas nozzle is located on one side or around the laser welding head 32, and sprays the protective gas into the welding area during the welding process to prevent oxidation of the molten pool. The flow rate of the protective gas is 5–25 L / min, preferably 10–15 L / min in this embodiment. In other embodiments, the protective gas may also be nitrogen, helium, or a mixture of argon and nitrogen.

[0047] The laser welding unit 3 also includes a weld seam tracking device 35, which is mounted on the laser welding head 32. This device is used to detect the actual position of the weld seam in real time during the welding process and feed back the position deviation signal to the central control system 5. In this embodiment, the weld seam tracking device 35 is a laser vision sensor, including a laser structured light projector and an industrial camera. The laser structured light projector projects a laser line onto the workpiece surface, and the industrial camera captures the deformation image of the laser line at the weld seam. The actual position of the weld seam is calculated using the triangulation principle. Based on the position deviation signal fed back by the weld seam tracking device 35, the central control system 5 controls the laser welding head drive mechanism 33 to adjust the position of the laser welding head 32, achieving precise tracking of the weld seam. In other embodiments, the weld seam tracking device 35 can also be a mechanical contact sensor.

[0048] like Figure 4As shown, the online inspection unit 4 is mounted on the frame 1 and located downstream of the laser welding unit 3 (i.e., along the conveying direction of the conveying device 2, after the laser welding unit 3), and is used to perform online real-time inspection of the weld seam after welding by the laser welding unit 3. Figure 4 As shown, the online inspection unit 4 includes an eddy current flaw detector 41, an ultrasonic inspection device 42, and a visual inspection device 43 arranged sequentially along the conveying direction.

[0049] Eddy current testing device 41 is positioned above the conveying device 2 downstream of the laser welding unit 3. It is used to perform eddy current testing on the weld after welding to detect defects such as cracks and incomplete penetration inside the weld. Eddy current testing device 41 includes an eddy current probe 411, an eddy current signal generator 412, and an eddy current signal analyzer 413.

[0050] The eddy current probe 411 maintains a distance of 0.5–3 mm from the weld surface during detection; in this embodiment, a distance of 1–2 mm is preferred. The eddy current probe 411 contains an excitation coil and a detection coil. The excitation coil generates a high-frequency alternating magnetic field under the excitation of an alternating current provided by the eddy current signal generator 412. This magnetic field induces eddy currents on the conductive weld metal surface, and these eddy currents generate their own magnetic fields. The detection coil detects these changes in the magnetic field. When defects such as cracks or incomplete penetration exist inside the weld, the distribution of the eddy currents changes, thereby causing a change in the output signal of the detection coil.

[0051] Eddy current signal generator 412 provides an excitation signal with a frequency of 10kHz to 10MHz to eddy current probe 411. In this embodiment, for weld inspection of aluminum alloy battery tray frame, an excitation frequency of 100kHz to 500kHz is preferred. The frequency and amplitude of eddy current signal generator 412 can be adjusted according to different inspection objects and inspection requirements.

[0052] Eddy current signal analyzer 413 is used to receive and analyze the eddy current feedback signal collected by eddy current probe 411. Eddy current signal analyzer 413 includes a signal amplification circuit, a filtering circuit, an analog-to-digital conversion circuit, and a digital signal processor. After amplification, filtering, and analog-to-digital conversion, the feedback signal is used by the digital signal processor for feature extraction and defect identification. Eddy current signal analyzer 413 transmits the analysis results (including the presence, type, and severity of defects) to the central control system 5. The eddy current flaw detection device 41 has a detection accuracy of up to 0.1 mm, effectively identifying minute defects inside the weld, and its detection speed is synchronized with the welding speed.

[0053] An ultrasonic testing device 42 is positioned above the conveying device 2 downstream of the eddy current flaw detector 41. It is used to perform ultrasonic testing on the weld to detect defects such as incomplete fusion, porosity, and slag inclusions near the surface and inside the weld. The ultrasonic testing device 42 includes an ultrasonic probe 421, an ultrasonic signal generator 422, and an ultrasonic signal analyzer 423.

[0054] A coupling medium (such as water or a coupling agent) is provided between the ultrasonic probe 421 and the weld surface to ensure that ultrasonic waves can be effectively transmitted from the probe to the workpiece. In this embodiment, water is used as the coupling medium, and a continuous water film is formed in the detection area by a water spraying device. The ultrasonic probe 421 is a phased array ultrasonic probe with multiple array elements, which can realize electronic scanning and focusing of the sound beam, improving the detection coverage and resolution.

[0055] The ultrasonic signal generator 422 provides a high-voltage electrical pulse signal to the ultrasonic probe 421, exciting the ultrasonic probe 421 to emit ultrasonic waves toward the weld. When the ultrasonic waves propagate in the weld, they will be reflected, refracted, and diffracted when they encounter defects (such as porosity, slag inclusions, lack of fusion, etc.). The ultrasonic probe 421 receives the reflected and diffracted wave signals and converts them into electrical signals.

[0056] The ultrasonic signal analyzer 423 is used to receive and analyze the ultrasonic signals acquired by the ultrasonic probe 421. In this embodiment, the ultrasonic detection device 42 uses ultrasonic TOFD (Time-of-Flight Diffraction) technology for signal acquisition and analysis. TOFD technology utilizes the diffraction waves at the defect endpoints for defect detection and location, enabling precise measurement of the defect's height and location, and exhibiting high detection sensitivity for defects near the weld surface and internally. The ultrasonic signal analyzer 423 transmits the analysis results to the central control system 5.

[0057] A visual inspection device 43 is positioned above the conveyor 2 downstream of the ultrasonic inspection device 42 and is used to visually inspect the surface quality of the weld. The visual inspection device 43 includes an industrial camera 431, a light source 432, and an image processor 433.

[0058] Industrial camera 431 is a high-resolution CCD industrial camera with a resolution ≥ 20 million pixels and a frame rate ≥ 30fps, used to acquire high-definition images of the weld surface. The lens of industrial camera 431 is either a fixed-focus lens or a zoom lens, with the focal length selected according to the required field of view and accuracy. In this embodiment, the field of view of industrial camera 431 is 50mm × 50mm, and the detection accuracy can reach 0.02mm.

[0059] Light source 432 is an LED ring light source or strip light source, positioned around industrial camera 431 to provide uniform and stable illumination for industrial camera 431, ensuring that the acquired image has sufficient contrast and clarity. The brightness and color temperature of light source 432 can be adjusted according to different workpiece surface conditions.

[0060] Image processor 433 is used to process and analyze weld images acquired by industrial camera 431. Image processor 433 includes an image preprocessing module, a feature extraction module, and a defect recognition module. The image preprocessing module performs preprocessing operations such as denoising, enhancement, and binarization on the original image; the feature extraction module extracts features such as the edge, texture, and grayscale of the weld from the preprocessed image; the defect recognition module identifies surface defects such as cracks, porosity, undercut, and incomplete filling on the weld surface based on the extracted features, and measures geometric parameters such as the width, height, and weld width of the weld. Image processor 433 transmits the processing results to the central control system 5.

[0061] like Figure 4 As shown, the central control system 5 is communicatively connected to both the laser welding unit 3 and the online detection unit 4. It receives detection data from the online detection unit 4 and sends welding parameter adjustment commands to the laser welding unit 3 based on the detection data. The central control system 5 includes a data acquisition module 51, a data analysis module 52, and a control command output module 53.

[0062] The data acquisition module 51 is used to acquire the detection data output by the online detection unit 4 in real time, including the eddy current detection data of the eddy current flaw detector 41, the ultrasonic detection data of the ultrasonic detection device 42, and the visual detection data of the visual inspection device 43. The data acquisition module 51 adopts a high-speed data acquisition card with a sampling rate ≥1MHz, which can acquire the data of each detection device in real time without delay.

[0063] The data analysis module 52 analyzes and processes the detection data acquired by the data acquisition module 51 to determine whether the weld quality is qualified and to identify the type and severity of defects when weld defects are detected. The data analysis module 52 has a built-in defect identification algorithm and judgment criteria. For eddy current detection data, the analysis module compares the measured eddy current signal with the standard eddy current signal to determine whether defects such as cracks or incomplete penetration exist. For ultrasonic detection data, the analysis module analyzes the waveform characteristics of the TOFD signal to determine whether defects such as porosity, slag inclusions, or lack of fusion exist. For visual inspection data, the analysis module uses image processing algorithms to identify the type of defects on the weld surface and measures geometric parameters. The data analysis module 52 outputs the analysis results (including whether the weld quality is qualified, defect type, and defect severity) to the control command output module 53 and can display them to the operator through a human-machine interface (such as a touch screen or monitor).

[0064] The control command output module 53 is used to send welding parameter adjustment commands to the laser welding unit 3 based on the analysis results of the data analysis module 52. The welding parameter adjustment commands include one or more of the following: laser power adjustment command, welding speed adjustment command, defocusing amount adjustment command, and shielding gas flow rate adjustment command. For example, when the eddy current flaw detector 41 detects an incomplete penetration defect in the weld, the control command output module 53 sends a command to the laser 31 to increase the laser power (e.g., increase the laser power from 4000W to 5000W), and simultaneously sends a command to the drive motor of the conveying device 2 to decrease the conveying speed (e.g., decrease the conveying speed from 18 m / min to 15 m / min) to increase the welding heat input and ensure penetration. When the visual inspection device 43 detects an undercut defect on the weld surface, the control command output module 53 sends a command to the laser welding head 32 to adjust the defocusing amount (e.g., adjust the defocusing amount from +1mm to +2mm) to improve weld formation.

[0065] The equipment also includes a welding parameter database 6, which is communicatively connected to the central control system 5. The welding parameter database 6 stores standard welding parameters and defect correction parameters corresponding to different battery tray frame models, material types, and weld formations. Standard welding parameters include optimal laser power, welding speed, defocusing amount, and shielding gas flow rate for a specific workpiece. Defect correction parameters include adjustments to each welding parameter when a specific type of defect is detected. When the online detection unit 4 detects a weld defect, the central control system 5 retrieves the corresponding defect correction parameters from the welding parameter database 6 and sends a welding parameter adjustment command to the laser welding unit 3 accordingly. The welding parameter database 6 can be updated and maintained through a human-machine interface, allowing operators to continuously optimize and supplement the parameters in the database based on actual production experience.

[0066] like Figure 5 As shown, the equipment also includes a workpiece positioning fixture 7, which is mounted on the conveying device 2 and used to position and clamp the battery tray frame workpiece 12. The workpiece positioning fixture 7 includes a positioning pin 71, a clamping cylinder 72, and a pressing block 73. The positioning pin 71 is a cylindrical or diamond-shaped pin, located on the bearing surface of the conveying device 2, and is used to engage with the positioning holes on the workpiece to achieve precise workpiece positioning. The clamping cylinder 72 is a double-acting cylinder, located on both sides of the conveying device 2, with the piston rod end of the clamping cylinder 72 connected to the pressing block 73. After the workpiece is placed on the conveying device 2 and positioned, the clamping cylinder 72 drives the pressing block 73 to move downwards, pressing the workpiece firmly against the bearing surface of the conveying device 2 to prevent displacement of the workpiece during welding and conveying. The working air pressure of the clamping cylinder 72 is 0.4–0.6 MPa, and the clamping force can be adjusted according to the workpiece weight and welding requirements.

[0067] like Figure 6 As shown, the equipment also includes a pre-welding cleaning device 8, which is positioned above the conveying device 2 upstream of the laser welding unit 3. This device cleans the area to be welded on the battery tray frame workpiece 12 before welding, removing oil, dust, and oxide layers. In this embodiment, the pre-welding cleaning device 8 is a laser cleaning device, including a laser cleaning head and a laser cleaning controller. The laser cleaning head emits short-pulse laser light onto the workpiece surface. The laser energy is absorbed by surface contaminants (oil, oxide layers, etc.), causing them to vaporize or peel off, thereby achieving the cleaning purpose. Laser cleaning has advantages such as being non-contact, abrasive-free, and free of chemical pollution. In other embodiments, the pre-welding cleaning device 8 can also be a plasma cleaning device or a mechanical brushing device.

[0068] The equipment also includes a marking device 9, which is positioned above the conveyor 2 downstream of the online inspection unit 4 and is used to mark the qualified battery tray frames. In this embodiment, the marking device 9 is a laser marking machine, which can engrave information such as QR codes, serial numbers, and production dates on the workpiece surface, facilitating product traceability and management. In other embodiments, the marking device 9 can also be an inkjet printer.

[0069] The equipment also includes a sorting device 10, which is located downstream of the online inspection unit 4 on one side of the conveyor 2. The sorting device 10 is used to separate qualified and unqualified products based on the inspection results of the online inspection unit 4. The sorting device 10 includes a pusher cylinder 101, a guide plate 102, and a collection box 103. The pusher cylinder 101 is located on one side of the conveyor 2, with its piston rod extending perpendicular to the conveying direction of the conveyor 2. The guide plate 102 is inclined on the other side of the conveyor 2, with its upper end connected to the edge of the conveyor 2 and its lower end leading to the collection box 103. When the central control system 5 determines that the current workpiece is an unqualified product, it controls the piston rod of the pusher cylinder 101 to extend, pushing the unqualified product from the conveyor 2 onto the guide plate 102. The unqualified product then slides down the guide plate 102 into the collection box 103. Qualified products continue to be conveyed forward along the conveyor 2 to the unloading station.

[0070] The equipment also includes a cooling device 11, which is used to cool the laser welding unit 3 and / or the online detection unit 4. In this embodiment, the cooling device 11 is a water-cooled device, including a chiller, cooling water pipelines, and a cooling water circulation pump. The chiller cools the cooling water to a set temperature (e.g., 20-25°C), and the cooling water circulates through the cooling water pipelines to the cooling channels of the laser 31 and the laser welding head 32, carrying away the heat generated by the laser 31 and the laser welding head 32 during operation, ensuring stable operation within a suitable temperature range. In other embodiments, the cooling device 11 may also be an air-cooled device.

[0071] Example 2 This embodiment provides a laser welding and online inspection method for a battery tray frame, using the integrated laser welding and online inspection equipment for the battery tray frame described in Embodiment 1. Figure 7 As shown, the method includes the following steps: Step S1: Workpiece loading and positioning.

[0072] The battery tray frame workpiece 12 is placed on the conveyor device 2, and the workpiece is positioned and clamped by the workpiece positioning fixture 7. Specifically, the operator or the automatic feeding robot places the battery tray frame workpiece 12 on the bearing surface of the conveyor device 2, aligns the positioning hole on the workpiece with the positioning pin 71, and inserts it. Then, the clamping cylinder 72 is activated, driving the clamping block 73 to move downwards and press the workpiece onto the conveyor device 2. After positioning and clamping are completed, the conveyor device 2 is started, transporting the workpiece towards the laser welding unit 3.

[0073] Step S2: Cleaning before welding.

[0074] When the workpiece moves with the conveyor 2 to below the pre-welding cleaning device 8, the pre-welding cleaning device 8 cleans the area of ​​the workpiece to be welded. In this embodiment, the laser cleaning device emits short-pulse lasers towards the area of ​​the workpiece to be welded to remove oil, dust, and oxide layers from the surface, ensuring welding quality. After cleaning, the workpiece continues to be conveyed with the conveyor 2 towards the laser welding unit 3.

[0075] Step S3: Laser welding.

[0076] When the workpiece moves to the area below the laser welding unit 3 along with the conveyor 2, the laser welding unit 3 is activated and performs laser welding on the area to be welded on the workpiece according to preset welding parameters. Specifically, the laser 31 generates a high-power laser beam, which is transmitted to the laser welding head 32 through an optical fiber. The laser welding head 32 focuses the laser beam onto the area to be welded on the workpiece. The laser welding head drive mechanism 33 (a six-axis industrial robot) drives the laser welding head 32 to move along the weld seam according to the preset welding trajectory. At the same time, the protective gas supply device 34 sprays protective gas (argon) into the welding area to prevent oxidation of the molten pool.

[0077] During the welding process, the weld tracking device 35 detects the actual position of the weld in real time and feeds back the position deviation signal to the central control system 5. The central control system 5 controls the laser welding head drive mechanism 33 to adjust the position of the laser welding head 32 according to the position deviation signal, so as to achieve precise tracking of the weld and ensure that the laser spot is always aligned with the center of the weld.

[0078] In this embodiment, the welding speed of the laser welding unit 3 is 8–18 m / min; the laser power is 3000–6000 W; the defocusing amount is +1–+3 mm; and the shielding gas is argon with a flow rate of 10–15 L / min. These parameters can be optimized and adjusted according to the workpiece material (such as aluminum alloy 6061, aluminum alloy 6005A, etc.), the workpiece thickness (generally 2–6 mm), and the weld type (butt weld, lap weld, fillet weld, etc.). After welding is completed, the workpiece continues to be conveyed towards the online detection unit 4 by the conveying device 2.

[0079] Step S4: Online detection.

[0080] After welding, the workpiece moves with the conveyor 2 to the underside of the online inspection unit 4, and passes through the eddy current flaw detector 41, the ultrasonic inspection device 42 and the visual inspection device 43 in sequence to inspect the internal defects, near-surface defects and surface quality of the weld.

[0081] S4-1: Eddy Current Testing. The workpiece first passes through the eddy current testing device 41. The eddy current probe 411 maintains a distance of 1-2 mm from the weld surface, and the eddy current signal generator 412 provides an excitation signal with a frequency of 100kHz-500kHz to the eddy current probe 411. The eddy current probe 411 induces eddy currents on the weld surface and detects changes in the eddy current magnetic field. The eddy current signal analyzer 413 analyzes the detection signal to determine whether there are defects such as cracks or incomplete penetration inside the weld. The detection accuracy of the eddy current testing device 41 is 0.1 mm, and the detection speed is synchronized with the welding speed (18 meters / minute).

[0082] S4-2: Ultrasonic Inspection. The workpiece then passes through the ultrasonic inspection device 42. The ultrasonic probe 421 contacts the weld surface via water coupling, and the ultrasonic signal generator 422 excites the ultrasonic probe 421 to emit ultrasonic waves towards the weld. The ultrasonic waves propagate in the weld and are reflected and diffracted when they encounter defects. The ultrasonic probe 421 receives the reflected and diffracted wave signals, and the ultrasonic signal analyzer 423 uses TOFD technology to analyze the signals to determine whether there are defects such as porosity, slag inclusions, and lack of fusion near the surface and inside the weld.

[0083] S4-3: Visual Inspection. The workpiece finally passes through the visual inspection device 43. The light source 432 provides uniform illumination for the industrial camera 431, which acquires high-resolution images of the weld surface. The image processor 433 processes and analyzes the images, identifies surface defects such as cracks, porosity, undercut, and incomplete filling on the weld surface, and measures geometric parameters such as the weld width, height, and weld width.

[0084] The three detection methods mentioned above complement each other. Eddy current testing focuses on detecting volumetric defects inside the weld, ultrasonic testing focuses on detecting near-surface and internal planar defects in the weld, and visual inspection focuses on detecting surface defects and geometric parameters of the weld. The combination of the three methods enables comprehensive and multi-level detection of weld quality.

[0085] Step S5: Data feedback and parameter adjustment.

[0086] The online inspection unit 4 transmits the inspection data to the central control system 5, which analyzes and processes the inspection data. Specifically, the data acquisition module 51 acquires the inspection data from the eddy current testing device 41, the ultrasonic testing device 42, and the visual inspection device 43 in real time; the data analysis module 52 analyzes the inspection data to determine whether the weld quality is qualified, and determines the type and severity of defects when defects are detected.

[0087] When a weld defect is detected, the central control system 5 retrieves the corresponding defect correction parameters from the welding parameter database 6 based on the defect type and severity, and sends a welding parameter adjustment command to the laser welding unit 3 via the control command output module 53. For example: When the eddy current flaw detector 41 detects an incomplete penetration defect, it indicates that the welding heat input is insufficient. The central control system 5 sends an instruction to the laser 31 to increase the laser power (e.g., increase the power by 500-1000W) and at the same time sends an instruction to the drive motor of the conveying device 2 to reduce the conveying speed (e.g., reduce the speed by 2-3 meters / minute) in order to increase the heat input and ensure the penetration. When the ultrasonic testing device 42 detects a porosity defect, it indicates that the protective gas is insufficient or the welding speed is too fast. The central control system 5 sends an instruction to the protective gas supply device 34 to increase the gas flow rate (e.g., increase the flow rate by 3-5 L / min), and at the same time sends an instruction to the drive motor of the conveying device 2 to reduce the conveying speed. When the vision inspection device 43 detects an undercut defect, it indicates that the laser focus position is incorrect or the welding speed is too fast. The central control system 5 sends an instruction to the laser welding head 32 to adjust the defocus amount (such as adjusting the defocus amount from +1mm to +2mm), or sends an instruction to the drive motor of the conveying device 2 to adjust the conveying speed. When the visual inspection device 43 detects that the weld width is insufficient, it indicates that the laser power is insufficient or the welding speed is too fast. The central control system 5 sends an instruction to the laser 31 to increase the laser power and / or sends an instruction to the drive motor of the conveying device 2 to reduce the conveying speed.

[0088] Through the aforementioned closed-loop control mechanism, this invention achieves real-time adaptive adjustment of welding parameters, which can promptly correct process deviations, prevent the recurrence of similar defects, and thus continuously optimize welding quality.

[0089] Step S6: Product marking and sorting.

[0090] After the inspection is completed, the workpiece continues to be conveyed forward by the conveyor 2 to the marking device 9 and the sorting device 10.

[0091] The marking device 9 marks the workpieces based on the detection results of the central control system 5. For workpieces that pass the inspection, the marking device 9 engraves information such as QR codes, serial numbers, and production dates on the workpiece surface for easy product traceability and management. For workpieces that fail the inspection, the marking device 9 can also engrave specific non-conformance marks for identification.

[0092] The sorting device 10 separates qualified and unqualified products based on the detection results of the online detection unit 4. When the central control system 5 determines that the current workpiece is a qualified product, the sorting device 10 does not operate, and the qualified product continues to be conveyed forward along the conveyor 2 to the unloading station, where it is removed by the operator or the automatic unloading robot. When the central control system 5 determines that the current workpiece is an unqualified product, the pusher cylinder 101 operates, pushing the unqualified product from the conveyor 2 onto the guide plate 102. The unqualified product slides down the guide plate 102 into the collection box 103, awaiting subsequent rework or scrapping. By separating unqualified products from the production line in a timely manner, the flow of unqualified products into subsequent processes is prevented, ensuring the quality of the outgoing products.

[0093] Example 3 The difference between this embodiment and Embodiment 1 is that the laser welding unit 3 includes two laser welding heads 32 and two sets of laser welding head driving mechanisms 33. The two laser welding heads 32 are respectively arranged on both sides of the conveying device 2, enabling simultaneous welding of the weld seams on both sides of the battery tray frame workpiece 12, further improving welding efficiency. The two laser welding heads 32 are each driven by two independent sets of laser welding head driving mechanisms 33, independently tracking and welding their respective weld seams. The two laser welding heads 32 can share a single laser 31 (the laser beam is split into two paths by a beam splitter), or they can each be equipped with an independent laser 31.

[0094] Example 4 The difference between this embodiment and Embodiment 1 is that the online inspection unit 4 only includes an eddy current testing device 41 and a visual inspection device 43, and does not include an ultrasonic testing device 42. This embodiment is suitable for application scenarios with relatively low inspection requirements. While ensuring the inspection of internal defects (through eddy current testing) and surface quality (through visual inspection) of the weld, it simplifies the equipment structure and reduces costs.

[0095] Example 5 The difference between this embodiment and Embodiment 1 is that the online inspection unit 4 only includes an ultrasonic testing device 42 and a visual inspection device 43, and does not include an eddy current testing device 41. This embodiment is suitable for application scenarios with high requirements for near-surface and internal defect detection of welds, but relatively low requirements for deep internal defect detection.

[0096] Example 6 The difference between this embodiment and Embodiment 1 is that the online inspection unit 4 only includes an eddy current flaw detector 41, and does not include an ultrasonic testing device 42 or a visual inspection device 43. This embodiment is suitable for applications that only require the detection of internal defects in the weld and have low requirements for surface quality.

[0097] Example 7 The difference between this embodiment and Embodiment 1 is that the conveying device 2 is a circular conveyor line, including a loading section, a welding section, an inspection section, a marking and sorting section, and a return section. The workpieces circulate on the circular conveyor line. After welding and inspection are completed, qualified products are taken out at the unloading station, and the unloaded workpiece positioning fixture 7 returns to the loading section through the return section, realizing the recycling of the workpiece positioning fixture 7.

[0098] Example 8 The difference between this embodiment and Embodiment 1 is that the equipment also includes a remote monitoring module. This module is communicatively connected to the central control system 5 and is used to transmit data such as the equipment's operating status, welding parameters, and test results to the remote monitoring center in real time, enabling remote monitoring and fault diagnosis of the equipment. The remote monitoring module supports both wired and wireless communication methods and can transmit data via Ethernet, Wi-Fi, 4G / 5G networks, etc.

[0099] Example 9 The difference between this embodiment and Embodiment 1 is that the equipment also includes an alarm device, which is connected to the central control system 5. When the online detection unit 4 detects a weld defect or a equipment malfunction, the central control system 5 controls the alarm device to issue an audible and visual alarm signal to remind the operator to handle the situation promptly. The alarm device includes a buzzer and an alarm indicator light.

[0100] Example 10 The difference between this embodiment and Embodiment 1 is that the laser 31 in the laser welding unit 3 is an adjustable annular spot laser. The adjustable annular spot laser can output a central spot and an annular spot, and the power of the central spot and the annular spot can be adjusted independently. This type of laser has unique advantages when welding aluminum alloys: the central spot provides the main welding heat input, while the annular spot preheats and post-heats the molten pool, effectively reducing spatter and porosity, and improving weld formation quality. In this embodiment, when welding the aluminum alloy battery tray frame, the central spot power is 3000–5000W, and the annular spot power is 1000–3000W. The diameter of the central spot and the outer diameter of the annular spot are selected according to the weld width.

[0101] This invention integrates a laser welding unit, an online inspection unit (including an eddy current flaw detector, an ultrasonic inspection device, and a visual inspection device), a central control system, a marking device, and a sorting device onto the same equipment. This achieves integrated processing of the battery tray frame from pre-welding cleaning, laser welding, online inspection, to product sorting, eliminating the inefficiency caused by the separation of welding and inspection processes in the traditional model.

[0102] This invention sequentially sets up an eddy current flaw detection device, an ultrasonic testing device, and a visual inspection device downstream of the laser welding unit to detect internal defects (cracks, incomplete penetration), near-surface and internal defects (porosity, slag inclusions, lack of fusion), and surface defects (cracks, porosity, undercut) of the weld, forming a comprehensive inspection system from the inside out and from the deep to the shallow, with wide inspection coverage and high accuracy.

[0103] The central control system of this invention interacts with the laser welding unit and the online detection unit in real time. When a weld defect is detected, it can automatically retrieve the defect correction parameters and send the welding parameter adjustment command to the laser welding unit, thus realizing closed-loop quality control of "welding-detection-feedback-adjustment".

[0104] The eddy current flaw detection device of the present invention has a detection accuracy of up to 0.1 mm, which can effectively identify tiny cracks and incomplete penetration defects inside the weld. The detection speed is synchronized with the welding speed (18 m / min), realizing real-time online detection under high-speed welding conditions.

[0105] The ultrasonic testing device of the present invention adopts TOFD technology, which can accurately detect defects such as porosity, slag inclusion, and lack of fusion near the surface and inside of the weld, and has the advantages of high detection sensitivity and accurate defect location.

[0106] This invention achieves adaptive adjustment of welding parameters through the coordinated operation of a welding parameter database and a central control system. It can automatically select the optimal correction strategy according to different defect types, thereby continuously optimizing welding quality.

[0107] Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art and related fields based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention. Structures, devices, and operating methods not specifically described and explained in the present invention, unless otherwise specified or limited, shall be implemented according to conventional means in the art.

Claims

1. An integrated laser welding and online inspection device for battery tray frames, comprising a frame, characterized in that, The rack is used to support and install the various functional units; A conveying device, which is mounted on the frame, is used to convey battery tray frame workpieces along a predetermined direction; A laser welding unit is provided on the frame and located above or to the side of the conveying device, for laser welding of the battery tray frame workpiece conveyed by the conveying device; An online inspection unit is provided, which is mounted on the frame and located downstream of the laser welding unit, and is used to perform online real-time inspection of the weld after it has been welded by the laser welding unit. The central control system is communicatively connected to both the laser welding unit and the online detection unit. It receives detection data from the online detection unit and sends welding parameter adjustment instructions to the laser welding unit based on the detection data.

2. The integrated laser welding and online inspection equipment for a battery tray frame according to claim 1, characterized in that, The laser welding unit includes a laser, a laser welding head, a laser welding head drive mechanism, and a protective gas supply device. The laser is a fiber laser or a disk laser; the laser welding head is mounted at the end of the laser welding head drive mechanism, which is a multi-axis robot or a three-dimensional motion platform, used to drive the laser welding head to move in three-dimensional space to align with the weld position; The protective gas supply device is used to provide protective gas to the welding area during the welding process.

3. The integrated laser welding and online inspection equipment for a battery tray frame according to claim 1, characterized in that, The online inspection unit includes an eddy current flaw detection device, which is located above the conveying device downstream of the laser welding unit and is used to perform eddy current flaw detection on the weld after welding. The eddy current flaw detection device includes an eddy current probe, an eddy current signal generator, and an eddy current signal analyzer. The eddy current signal analyzer is used to receive and analyze the eddy current feedback signal collected by the eddy current probe.

4. The integrated laser welding and online inspection equipment for a battery tray frame according to claim 1, characterized in that, The online inspection unit also includes an ultrasonic inspection device, which is located above the conveying device downstream of the eddy current flaw detector and is used to perform ultrasonic inspection on the weld. The ultrasonic testing device includes an ultrasonic probe, an ultrasonic signal generator, and an ultrasonic signal analyzer. The ultrasonic signal generator provides an excitation signal to the ultrasonic probe, the ultrasonic probe emits ultrasonic waves toward the weld and receives reflected waves, and the ultrasonic signal analyzer determines whether there are defects inside the weld based on the received reflected wave signals.

5. The integrated laser welding and online inspection equipment for a battery tray frame according to claim 1, characterized in that, The visual inspection device is located above the conveying device downstream of the ultrasonic inspection device and is used to visually inspect the surface quality of the weld. The visual inspection device includes an industrial camera, a light source, and an image processor.

6. The integrated laser welding and online inspection equipment for a battery tray frame according to claim 1, characterized in that, The central control system includes a data acquisition module, a data analysis module, and a control command output module; The data acquisition module is used to acquire the detection data output by the online detection unit in real time; The data analysis module is used to analyze and process the detection data, determine whether the weld quality is qualified, and determine the defect type and severity when weld defects are detected. The control command output module is used to send welding parameter adjustment commands to the laser welding unit based on the analysis results of the data analysis module; The welding parameter adjustment commands include one or more of the following: laser power adjustment command, welding speed adjustment command, defocusing amount adjustment command, and shielding gas flow rate adjustment command.

7. The integrated laser welding and online inspection equipment for a battery tray frame according to claim 1, characterized in that, The equipment also includes a workpiece positioning fixture, which is disposed on the conveying device and is used to position and clamp the battery tray frame workpiece. The workpiece positioning fixture includes a positioning pin, a clamping cylinder, and a pressing block. The positioning pin is used to cooperate with the positioning hole on the workpiece to achieve precise positioning. The clamping cylinder drives the pressing block to press the workpiece onto the conveying device.

8. The integrated laser welding and online inspection equipment for a battery tray frame according to claim 1, characterized in that, The equipment also includes a pre-welding cleaning device, which is located above the conveying device upstream of the laser welding unit and is used to clean the area to be welded of the battery tray frame workpiece before welding. The pre-welding cleaning device is one of a laser cleaning device, a plasma cleaning device, or a mechanical brushing device.

9. The integrated laser welding and online inspection equipment for a battery tray frame according to claim 1, characterized in that, The equipment also includes a marking device, which is located above the conveying device downstream of the online detection unit and is used to mark the battery tray frames that have passed the inspection. The marking device is a laser marking machine or an inkjet printer.

10. A method for laser welding and online inspection of a battery tray frame, characterized in that, The process, employing the integrated laser welding and online inspection equipment for the battery tray frame as described in any one of claims 1-9, includes the following steps: Step S1: Workpiece loading and positioning: Place the battery tray frame workpiece on the conveying device, and position and clamp the workpiece using the workpiece positioning fixture; Step S2: Pre-welding cleaning: The pre-welding cleaning device is used to clean the area of ​​the workpiece to be welded, removing oil, dust and oxide layer; Step S3: Laser welding: Start the laser welding unit and perform laser welding on the area to be welded of the workpiece according to the preset welding parameters; during the welding process, the weld seam tracking device monitors the actual position of the weld seam in real time, and the central control system adjusts the position of the laser welding head according to the position deviation signal; Step S4: Online inspection: After welding, the workpiece moves with the conveying device to the bottom of the online inspection unit and passes through the eddy current flaw detection device, the ultrasonic detection device and the visual inspection device in sequence to inspect the internal defects, near-surface defects and surface quality of the weld. Step S5: Data Feedback and Parameter Adjustment: The online detection unit transmits the detection data to the central control system, which analyzes and processes the data. When a weld defect is detected, the central control system retrieves the corresponding defect correction parameters from the welding parameter database according to the defect type and severity, and sends a welding parameter adjustment command to the laser welding unit. Step S6: Product marking and sorting: The marking device marks the qualified workpieces, and the sorting device separates qualified and unqualified products according to the test results.

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