Weld quality detection method and weld detection system

Abstract

The present application discloses a method for detecting weld quality and a weld detection system. The detection method comprises: using a visual recognition device to obtain an image of the detection area of ​​the welding assembly; using an ultrasonic detection device to scan along the weld to obtain the ultrasonic detection area of ​​the detection area; wherein the ultrasonic detection area is the welding area between the second welding part and the bottom wall of the depression; comparing the ultrasonic detection area with the area threshold; if the ultrasonic detection area is greater than or equal to the area threshold, the weld quality is determined to be qualified; if the ultrasonic detection area is less than the area threshold, the weld quality is determined to be unqualified. The present application can quantitatively evaluate the weld quality and improve the accuracy of weld quality detection.

Description

Technical Field

[0001] The present application relates to the technical field of product detection, and in particular to a weld quality detection method and a weld detection system. Background Art

[0002] For products assembled by welding, welds are usually left on the products. Taking the battery module as an example, when the end plate and the side plate are welded, a weld is formed between the end plate and the side plate. Whether the connection at the weld is reliable is one of the important factors affecting product performance.

[0003] At present, for welding products with hemming structures, the weld inspection method cannot directly detect the penetration depth, and the weld quality inspection method has low accuracy. Summary of the invention

[0004] The embodiments of the present application provide a weld quality detection method and a weld detection system, which can improve the accuracy of weld quality detection.

[0005] In a first aspect, an embodiment of the present application provides a method for detecting weld quality, which is used to detect the welding quality of a welding assembly, wherein the welding assembly includes a first welding part and a second welding part welded to each other, the first welding part is provided with a recessed step, a portion of the second welding part is located in the recessed step, the recessed step includes a recessed side wall and a recessed bottom wall connected to each other, and the second welding part is welded to the recessed side wall and the recessed bottom wall respectively; the detection method includes:

[0006] Using a visual recognition device to obtain an image of the inspection area of ​​the welding assembly;

[0007] An ultrasonic detection device is used to scan along the weld to obtain an ultrasonic detection area of ​​the detection area; wherein the ultrasonic detection area is a welding area between the second welding part and the bottom wall of the recess;

[0008] Compare the ultrasonic detection area with the area threshold;

[0009] If the ultrasonic detection area is greater than or equal to the area threshold, the weld quality is judged to be qualified;

[0010] If the ultrasonic detection area is smaller than the area threshold, the weld quality is judged to be unqualified.

[0011] In the above scheme, for the welding assembly with a edging structure, the image is obtained by the visual recognition device and the ultrasonic detection area is obtained by the ultrasonic detection device, and the area is compared with the area threshold, that is, the welding area between the second welding part and the bottom wall of the recess is compared with the area threshold. It is possible to reversely infer whether the penetration depth meets the requirements, quantitatively evaluate the weld quality, and improve the accuracy of weld quality detection.

[0012] In some embodiments, the weld centerline of the inspection area is acquired by a visual recognition device, and an ultrasonic inspection device is used to scan along the weld based on the weld centerline.

[0013] In the above scheme, the weld centerline of the inspection area is obtained by the visual recognition device, and then the ultrasonic detection device is used to scan along the weld based on this, making the ultrasonic detection path more accurate. The weld centerline provides a clear guide for ultrasonic detection, avoiding deviations during the ultrasonic detection process, thereby improving the accuracy of the ultrasonic detection device in obtaining the ultrasonic detection area, and further improving the accuracy of the entire weld quality detection.

[0014] In some embodiments, the weld centerline is the connection interface between the recessed sidewall and the second weldment.

[0015] In the above scheme, by setting the connection interface between the recessed side wall and the second welded part as the weld centerline, the weld centerline is determined more clearly and accurately. In the actual detection process, the operator can more easily find the weld centerline according to this clear definition, thereby ensuring that the ultrasonic detection device scans along the correct path, thereby improving the detection efficiency and accuracy.

[0016] In some embodiments, the area threshold is S0, S0 satisfies: S0 = a×L, a is the width threshold of the weld, a satisfies: 0.2≤a≤0.9, and L is the length of the weld.

[0017] In the above scheme, different weld length and width thresholds can be adjusted according to actual conditions, so as to adapt to the weld quality inspection requirements of different welding components and improve the versatility and adaptability of the inspection method.

[0018] In some embodiments, a satisfies: 0.6≤a≤0.9.

[0019] In the above scheme, by limiting a narrower range, the area threshold can be determined more accurately, which is more in line with the quality standards of most welded components in actual production, and helps to improve the reliability and accuracy of weld quality detection.

[0020] In some embodiments, the weld centerline of the detection area is obtained by a visual recognition device, and the weld length is the length of the weld along the weld centerline.

[0021] In the above scheme, by clarifying the method of obtaining the value of the weld length, the measurement of the weld length is made more accurate and standardized, and the area threshold can be calculated more accurately, thereby providing a more reliable basis for judging whether the weld quality is qualified and further improving the detection accuracy.

[0022] In some embodiments, before the step of using a visual recognition device to acquire an image of the inspection area of ​​the welding assembly, the step further includes:

[0023] Ultrasonic testing equipment is used to perform flaw detection operations on the inspection area.

[0024] In the above scheme, the flaw detection operation can detect obvious weld defects that may exist in the inspection area in advance, such as cracks, pores, etc., providing a more reliable basis for subsequent visual recognition and ultrasonic inspection area measurement. If serious defects are found during the flaw detection process, they can be processed in advance to avoid unnecessary subsequent inspection processes and improve inspection efficiency.

[0025] In some embodiments, the flaw detection operation includes scanning the inspection area, recording the inspection data, and identifying and processing weld defects.

[0026] In the above scheme, the scanning process can fully cover the inspection area, and the recorded inspection data can provide a basis for subsequent analysis and processing. Identifying and processing weld defects can timely discover and solve potential quality problems, further improving the integrity and effectiveness of weld quality inspection of welded components.

[0027] In some embodiments, the steps of identifying and addressing weld defects include:

[0028] Calculate the size, depth and type of defects based on the amplitude, position and waveform characteristics of the ultrasonic reflection signal;

[0029] Determine whether the defect exceeds the defect threshold based on the acceptance level in the inspection standard;

[0030] If the defect exceeds the acceptance criteria, output repair suggestion instructions.

[0031] In the above scheme, the size, depth and type of the defect are calculated based on the amplitude, position and waveform characteristics of the ultrasonic reflection signal, so as to accurately understand the specific situation of the weld defect; whether the defect exceeds the defect threshold is determined according to the acceptance level in the detection standard, so as to objectively judge the severity of the defect; if the defect exceeds the acceptance standard, the repair suggestion instruction is output, which provides specific guidance for repairing weld defects and helps to improve the quality and reliability of welded components.

[0032] In some embodiments, after the step of comparing the ultrasonic detection area with the area threshold, the step further includes:

[0033] After the test is completed, the data is stored and the ultrasonic testing device is calibrated and maintained.

[0034] In the above scheme, storing data can facilitate the subsequent traceability and analysis of the test results, providing data support for quality control and process improvement; calibrating and maintaining the ultrasonic detection device can ensure the accuracy and stability of the ultrasonic detection device, ensure the reliability of subsequent test results, and extend the service life of the ultrasonic detection device.

[0035] In some embodiments, the step of performing calibration maintenance on the ultrasonic detection device includes:

[0036] Use standard test blocks to regularly calibrate the sound velocity and thickness measurement accuracy of ultrasonic testing equipment.

[0037] In the above scheme, the standard test block has known physical properties. By comparing and calibrating with the standard test block, the errors that may occur in the long-term use of the ultrasonic detection device can be effectively eliminated, ensuring that the ultrasonic detection device is always in an accurate and reliable working state, thereby improving the accuracy of weld quality detection.

[0038] In a second aspect, the present application provides a weld detection system, applying any of the above-mentioned detection methods, the weld detection system includes:

[0039] Ultrasonic testing device, used to scan and inspect welds;

[0040] A visual recognition device is used to obtain an image of an inspection area of ​​a welding assembly.

[0041] In the above scheme, the image is obtained by the visual recognition device and the ultrasonic detection area is obtained by the ultrasonic detection device, and the area is compared with the area threshold, that is, the welding area between the second welded part and the bottom wall of the recess is compared with the area threshold, so as to reversely infer whether the penetration depth meets the requirements, quantitatively evaluate the weld quality, and improve the accuracy of weld quality detection.

[0042] In some embodiments, the weld inspection system further includes an alarm device, which is triggered to sound an alarm when the weld is determined to be unqualified.

[0043] In the above scheme, an alarm device is added to the weld inspection system, and when the weld is judged to be unqualified, the alarm device is triggered to alarm. This enables the operator to know the unqualified weld quality in time, so as to take timely measures to deal with it, avoid unqualified products from entering the next production link, improve the quality control level of the production process, and reduce the losses caused by weld quality problems.

[0044] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0046] Figure 1 This is a schematic diagram of the structure of a battery module of some embodiments of the present application;

[0047] Figure 2 This is a schematic diagram of the structure of a welding assembly in some embodiments of the present application;

[0048] Figure 3 A schematic diagram of a detection method according to some embodiments of the present application;

[0049] Figure 4 Schematic diagram of the flow of detection methods of other embodiments of the present application;

[0050] Figure 5 is a schematic diagram of a process for identifying and processing weld defects in some embodiments of the present application;

[0051] Figure 6 is a schematic flow chart of the detection method of some other embodiments of the present application;

[0052] Figure 7 is a block diagram of a weld detection system according to some embodiments of the present application;

[0053] Figure 8 It is a block diagram of a weld detection system according to some other embodiments of the present application.

[0054] Description of reference numerals:

[0055] 400, battery module; 20, battery cell; 100, welding assembly; 11, first welding part; 111, recessed step; 112, recessed side wall; 113, recessed bottom wall; 12, second welding part; 121, first connecting part; 122, second connecting part; 200, weld detection system; 30, visual recognition device; 40, ultrasonic detection device; 50, data processing module; 60, data storage module; 70, alarm device. DETAILED DESCRIPTION

[0056] The following detailed description and drawings of the embodiments of the present application are used to illustrate the principles of the present application, but cannot be used to limit the scope of the present application, that is, the present application is not limited to the described embodiments.

[0057] In the description of the present application, it should be noted that, unless otherwise specified, "multiple" means more than two; the terms "upper", "lower", "left", "right", "inside", "outside", etc., indicating the orientation or positional relationship, are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. "Vertical" is not strictly vertical, but is within the allowable error range. "Parallel" is not strictly parallel, but is within the allowable error range.

[0058] Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0059] The directional words appearing in the following description are all directions shown in the figures, and do not limit the specific structure of this application. In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0060] The principle of ultrasonic testing of welds is to detect defects inside the weld by emitting ultrasonic waves and using their propagation characteristics in the weld. The basic principle of ultrasonic testing is to use the propagation and interaction characteristics of high-frequency mechanical waves in materials. When ultrasonic waves propagate in the weld, reflection, refraction and scattering will occur when they encounter defects (such as cracks, pores, inclusions, etc.). These reflected or scattered waves are received by the sensor and converted into electrical signals. By analyzing these electrical signals, it can be determined whether there are defects in the weld, as well as the type, location and size of the defects; for penetrating weld structures, quantitative detection of weld width can be achieved due to the existence of interfaces, but for hemming structures, it is difficult to quantitatively detect the penetration depth directly. The weld detection method cannot directly detect the penetration depth, and the weld quality detection method has low accuracy.

[0061] In order to solve the above-mentioned technical problems, an embodiment of the present application provides a method for detecting weld quality, which is used to detect the welding quality of a welding assembly, wherein the welding assembly includes a first welding part and a second welding part welded to each other, the first welding part is provided with a recessed step, a portion of the second welding part is located in the recessed step, the recessed step includes a recessed side wall and a recessed bottom wall connected to each other, and the second welding part is welded to the recessed side wall and the recessed bottom wall respectively; the detection method includes: using a visual recognition device to obtain an image of a detection area of ​​the welding assembly; using an ultrasonic detection device to scan along the weld to obtain an ultrasonic detection area of ​​the detection area; wherein the ultrasonic detection area is the welding area of ​​the second welding part and the recessed bottom wall; comparing the size of the ultrasonic detection area with an area threshold; if the ultrasonic detection area is greater than or equal to the area threshold, the weld quality is determined to be qualified; if the ultrasonic detection area is less than the area threshold, the weld quality is determined to be unqualified. For welding components with a edging structure, images are obtained by a visual recognition device and an ultrasonic detection device is used to obtain an ultrasonic detection area, and the area is compared with an area threshold, that is, the welding area between the second welded part and the bottom wall of the recess is compared with the area threshold. This can reversely infer whether the penetration depth meets the requirements, quantitatively evaluate the weld quality, and improve the accuracy of weld quality detection.

[0062] The embodiments of the present application provide a method for preparing a solid-state battery cell, a battery device, and an electric device. The battery device can provide electrical energy to the electric device or store electrical energy. The electric device can be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery car, an electric car, a ship, a spacecraft, and the like. Among them, the electric toy can include a fixed or mobile electric toy, for example, a game console, an electric car toy, an electric ship toy, an electric airplane toy, and the like, and the spacecraft can include an airplane, a rocket, a space shuttle, a spacecraft, and the like.

[0063] In some embodiments, the battery cell may include a lithium-ion secondary battery cell, a lithium-ion primary battery cell, a lithium-sulfur battery cell, a sodium-lithium-ion battery cell, a sodium-ion battery cell, or a magnesium-ion battery cell, etc., which is not limited in the embodiments of the present application. The battery cell may be cylindrical, flat, rectangular, or in other shapes. Battery cells are generally divided into three types according to the packaging method: cylindrical battery cells, square battery cells, and soft-pack battery cells.

[0064] The battery device mentioned in the embodiments of the present application may include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly may include a plurality of battery cells, and the plurality of battery cells are connected in series, in parallel or in mixed connection through a busbar.

[0065] In some embodiments, the battery cell assembly is generally formed by arranging a plurality of battery cells; as an example, the battery cell assembly may be a battery module, which is formed by arranging and fixing a plurality of battery cells to form an independent module. As an example, the battery module may be formed by bundling a plurality of battery cells by a cable tie.

[0066] In some embodiments, the battery device may be a battery pack, which includes a case and one or more battery cell assemblies, wherein the battery cell assemblies are accommodated in the case.

[0067] As an example, the battery cell assembly may be a battery module, and the battery cell assembly may be accommodated in the box by fixing the battery module in the box.

[0068] As an example, the battery cell assembly may also be housed in the case by directly fixing a plurality of battery cells to the case.

[0069] In the first aspect, an embodiment of the present application provides a method for detecting weld quality, which is used to detect the welding quality of a welding assembly 100. The welding assembly 100 includes a first welding part 11 and a second welding part 12 welded to each other. The first welding part 11 is provided with a recessed step 111. A portion of the second welding part 12 is located in the recessed step 111. The recessed step 111 includes a recessed side wall 112 and a recessed bottom wall 113 connected to each other. The second welding part 12 is welded to the recessed side wall 112 and the recessed bottom wall 113, respectively.

[0070] The second welding part 12 is bent, and includes a first connection part 121 and a second connection part 122 connected to each other. The first connection part 121 is located in the recessed step 111 to form an edge structure. The first connection part 121 is welded to the first welding part 11. Ultrasonic waves or lasers can be used to weld the first connection part 121 and the first welding part 11. The welding is performed along the contact surface between the first connection part 121 and the recessed side wall 112 of the first welding part 11. The first connection part 121 and the recessed bottom wall 113 of the first welding part 11 can also be covered by the weld, so a portion of the recessed bottom wall 113 can also be welded to the first connection part 121 at the portion corresponding to the weld.

[0071] The first welding member 11 may be an end plate of the battery module 400, and the second welding member 12 may be a side plate of the battery module 400. The end plate is located at the upper end of the plurality of arranged battery cells 20, and the side plate is bent, with a portion of the side plate located at the side of the plurality of arranged battery cells 20, and another portion of the side plate located in the concave step 111 of the end plate, forming an edge wrapping structure.

[0072] Figure 1 Schematic diagram of the structure of the battery module 400 of some embodiments of the present application. Figure 1As shown, in the battery device, there can be multiple battery cells 20, and the multiple battery cells 20 can be connected in series, in parallel, or in mixed connection. Mixed connection means that the multiple battery cells 20 are both connected in series and in parallel. Multiple battery cells 20 can be directly connected in series, in parallel, or in mixed connection, and then the multiple battery cells 20 form a battery module 400 as a whole, which is accommodated in the box; of course, the battery device can also be a form in which multiple battery cells 20 are first connected in series, in parallel, or in mixed connection to form a battery module 400, and then the multiple battery modules 400 are connected in series, in parallel, or in mixed connection to form a whole, and are accommodated in the box. The battery device can also include other structures. For example, the battery device can also include a busbar component for realizing electrical connection between multiple battery cells 20.

[0073] Please refer to Figure 2 and Figure 3 , the detection method of the embodiment of the present application includes:

[0074] S10 , using the visual recognition device 30 to obtain an image of the inspection area of ​​the welding assembly 100 .

[0075] The visual recognition device 30 may include a CCD (charge coupled device) camera and an image processing unit.

[0076] The welding assembly 100 is fixed on the detection platform, and the recessed step 111 area of ​​the welding assembly 100 is photographed from multiple angles by a CCD camera to obtain a high-resolution image containing the weld contour. The geometric features of the weld are identified using image processing algorithms (such as edge detection and contour extraction), including the junction position between the recessed side wall 112 and the recessed bottom wall 113, and the edge contour of the embedded portion of the second welding member 12. Based on the identification results, the scanning range of the ultrasonic detection module is determined, and the detection area boundary is marked in the image.

[0077] According to the material (such as aluminum alloy, steel, etc.) and thickness of the first welding part 11 and the second welding part 12, the exposure time, focal length and light source intensity of the CCD camera are adjusted to ensure that the image clarity meets the feature extraction requirements.

[0078] S20, use the ultrasonic detection device 40 to scan along the weld to obtain the ultrasonic detection area of ​​the detection area; wherein the ultrasonic detection area is the welding area between the second welding part 12 and the recessed bottom wall 113.

[0079] First, the ultrasonic detection device 40 can be calibrated, a probe matching the sound velocity of the welding material is selected, and a distance-amplitude curve is calibrated using a standard test block to ensure that the detection sensitivity meets the preset standard. According to the detection area boundary provided by the visual recognition device 30, the scanning path of the probe, i.e., the scanning speed, is set.

[0080] Then, ultrasonic scanning and data collection can be performed. A coupling agent (such as glycerin or water-based coupling agent) can be evenly applied on the surfaces of the first welding part 11 and the second welding part 12, and the probe can be driven to move along the scanning path to emit ultrasonic waves and receive reflected signals in real time. Then, the detection area is calculated, and the effective welding area between the second welding part 12 and the recessed bottom wall 113 is identified by analyzing the amplitude and position of the reflected signal. The determination condition of the effective welding area is: the reflected amplitude is lower than the evaluation line of the distance-amplitude curve, and the signal waveform is continuous and stable.

[0081] When welding is performed along the contact interface between the recessed side wall 112 and the second welding part 12, the second welding part 12 and the recessed bottom wall 113 of the first welding part 11 can also be covered by the weld. During ultrasonic testing, the ultrasonic wave will be reflected or scattered at the contact interface between the second welding part 12 and the recessed bottom wall 113, and these reflections or scatterings are received by the sensor and converted into electrical signals, so that the welding area between the second welding part 12 and the recessed bottom wall 113, that is, the ultrasonic testing area, can be determined.

[0082] S30, comparing the size of the ultrasonic detection area with the area threshold; if the ultrasonic detection area is greater than or equal to the area threshold, the weld quality is determined to be qualified; if the ultrasonic detection area is less than the area threshold, the weld quality is determined to be unqualified.

[0083] The ultrasonic detection device 40 may include an ultrasonic detector, an ultrasonic flaw detector, an ultrasonic probe, etc. The weld detection system 200 may also include a data processing module 50 and a data storage module 60. The data processing module 50 may be used to calculate the area threshold and the ultrasonic detection area, and output the determination result; the data storage module 60 may be used to store the detection data and the equipment calibration record.

[0084] When the weld quality is judged to be qualified, a report containing the test data can be generated. When the weld quality is judged to be unqualified, an audible and visual alarm can be triggered and the defect location can be marked, and repair suggestions (such as the coordinates of the repair welding area and repair welding parameters) can be output at the same time.

[0085] In the above scheme, for the welding assembly 100 with a edging structure, the image is obtained by the visual recognition device 30 and the ultrasonic detection area is obtained by the ultrasonic detection device 40, and the area is compared with the area threshold, that is, the welding area between the second welding part 12 and the recessed bottom wall 113 is compared with the area threshold, so as to reversely infer whether the penetration depth meets the requirements, quantitatively evaluate the weld quality, and improve the accuracy of weld quality detection.

[0086] In some embodiments, the weld centerline of the inspection area is acquired by a visual recognition device 30, and an ultrasonic inspection device 40 is used to scan along the weld based on the weld centerline.

[0087] The connection interface between the recessed side wall 112 and the second welding part 12 can be directly used as the center line of the weld; or a CCD camera can be used to shoot the detection area of ​​the welding assembly 100 at multiple angles to obtain a clear image containing the weld contour, and the image is preprocessed, including grayscale, noise reduction and contrast enhancement, to improve the recognition accuracy of the weld edge, and then an edge measurement algorithm is used to extract the edge contour of the weld area, and based on the edge contour, the upper edge line and the lower edge line of the weld are fitted, and then the center line of the weld is calculated between the upper edge line and the lower edge line of the weld by the equidistant interpolation method.

[0088] The coordinate data of the center line is stored and transmitted to the ultrasonic detection device 40 to serve as a guide for the scanning path.

[0089] In the above scheme, the weld centerline of the detection area is obtained by the visual recognition device 30, and then the ultrasonic detection device 40 is used to scan along the weld based on this, so that the path of ultrasonic detection is more accurate. The weld centerline provides a clear guide for ultrasonic detection, avoiding deviations during ultrasonic detection, thereby improving the accuracy of the ultrasonic detection device 40 in obtaining the ultrasonic detection area, and further improving the accuracy of the entire weld quality detection.

[0090] In some embodiments, the weld centerline is the connection interface between the recessed sidewall 112 and the second weld member 12 .

[0091] The collected image is transmitted to the data processing module 50 for analysis. The data processing module 50 may be installed with special image processing software, which can perform pre-processing operations such as graying, filtering, and edge detection on the image to enhance the characteristic information of the image. Then, through the image recognition algorithm, the connection interface between the recessed side wall 112 and the second welded part 12 is accurately identified in the pre-processed image, and it is determined as the weld centerline. In order to improve the accuracy of the determination, a multiple recognition and averaging method can be used to collect and analyze multiple images of the same detection area, and then the average value is taken as the final weld centerline.

[0092] In the above solution, by setting the connection interface between the recessed side wall 112 and the second welding member 12 as the weld centerline, the weld centerline is determined more clearly and accurately. In the actual detection process, the operator can more conveniently find the weld centerline according to this clear definition, thereby ensuring that the ultrasonic detection device 40 scans along the correct path, thereby improving the detection efficiency and accuracy.

[0093] In some embodiments, the area threshold is S 0 , S 0 Satisfaction: S 0=a×L, a is the width threshold of the weld, a satisfies: 0.2mm≤a≤0.9mm, and L is the length of the weld.

[0094] The weld width threshold a refers to the weld width corresponding to the ultrasonic detection area under the minimum standard. The weld length L refers to the length of the weld along the weld centerline. The direction of the weld length is perpendicular to the direction of the weld width.

[0095] When determining the width threshold a, before the test piece is tested, the ultrasonic detection area of ​​multiple battery cell 20 samples can be tested to obtain the ultrasonic detection area of ​​multiple battery cell 20 samples, and then the average value is taken to calculate the average weld width, that is, the weld width threshold.

[0096] When testing the test piece, it is only necessary to obtain the ultrasonic detection area and then compare it with the area threshold. When the weld length is the same, the larger the ultrasonic detection area and the larger the weld width, the greater the welding strength between the first weld 11 and the second weld 12, and the penetration depth can meet the requirements.

[0097] Wherein, a can be any value between 0.2 mm and 0.9 mm. For example, a can be 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.75 mm, 0.88 mm, or 0.9 mm.

[0098] In the above scheme, different weld length and width thresholds can be adjusted according to actual conditions, so as to adapt to the weld quality inspection requirements of different welding assemblies 100, thereby improving the versatility and adaptability of the inspection method.

[0099] In some embodiments, a satisfies: 0.6 mm ≤ a ≤ 0.9 mm.

[0100] Wherein, a can be any value between 0.6 mm and 0.9 mm. For example, a can be 0.6 mm, 0.7 mm, 0.8 mm, 0.85 mm, or 0.9 mm.

[0101] In the above scheme, by limiting a narrower range, the area threshold can be determined more accurately, which is more in line with the quality standards of most welded assemblies 100 in actual production, and helps to improve the reliability and accuracy of weld quality detection.

[0102] In some embodiments, the weld centerline of the detection area is acquired by the visual recognition device 30, and the weld length is the length of the weld along the weld centerline.

[0103] First, a high-resolution CCD camera can be used to photograph the inspection area of ​​the welding assembly 100 to obtain a high-definition image including the recessed step 111 and the second welding part 12. The connection interface between the recessed side wall 112 and the second welding part 12 is identified by an image processing algorithm (such as edge detection and contour extraction). The connection interface between the recessed side wall 112 and the second welding part 12 is defined as the weld centerline, and the geometric features of the connection interface (such as a straight line or a curve) are extracted, and its coordinate data is calculated as a basis for the scanning path of the ultrasonic detection device 40.

[0104] In the above scheme, by clarifying the method of obtaining the value of the weld length, the measurement of the weld length is made more accurate and standardized, and the area threshold can be calculated more accurately, thereby providing a more reliable basis for judging whether the weld quality is qualified and further improving the detection accuracy.

[0105] like Figure 4 As shown, in some embodiments, before the step of using the visual recognition device 30 to acquire an image of the detection area of ​​the welding assembly 100, the method further includes:

[0106] S40, using the ultrasonic detection device 40 to perform flaw detection on the detection area.

[0107] Before ultrasonic testing of welds, you can do some preparations before testing, make sure that the ultrasonic flaw detector, probe, coupling agent and other equipment are complete, and check whether they are in normal working condition. Be familiar with the specifications and dimensions, material grades, welding methods, groove forms, surface conditions, etc. of the test object, and understand the technical requirements of the test, such as the test standards, test technology levels, test ratios, test locations, acceptance standards, etc.

[0108] Then adjust the instrument, such as using a test block to calibrate the distance to ensure the accuracy of the instrument settings. You can also test the probe, perform leading edge calibration and K value calibration to ensure the accuracy and sensitivity of the probe. Make a distance-amplitude curve: Determine the sensitivity and detection range of the flaw detection through testing.

[0109] You can also prepare the test surface. For the marking test area, use chalk or black pen to mark the test area and the moving area of ​​the probe. For cleaning the test surface, make sure it is clean and free of oil and impurities, and polish it if necessary.

[0110] Finally, connect the probe and the instrument, and perform a power-on self-test to ensure that the instrument is working properly. Complete the basic settings: adjust the detection range, material sound velocity, pulse shift and other parameters to ensure that the instrument is in the best working condition.

[0111] According to the material (eg, steel, aluminum alloy) and thickness of the welding assembly 100 , a probe with a suitable frequency is selected, and the incident angle of the probe is adjusted to align with the detection area.

[0112] Apply coupling agent (such as glycerin or water-based coupling agent) evenly on the surface of the inspection area, and drive the probe to perform a preliminary scan along the preset path. Transmit ultrasonic waves in real time and receive reflected signals, and record the reflected amplitude, sound path data and probe coordinates at each position during the scanning process. By analyzing the amplitude and waveform characteristics of the reflected signal, identify the obvious defects (such as cracks, pores, slag inclusions, etc.) that may exist in the inspection area.

[0113] In the above scheme, the flaw detection operation can detect obvious weld defects that may exist in the inspection area in advance, such as cracks, pores, etc., providing a more reliable basis for subsequent visual recognition and ultrasonic inspection area measurement. If serious defects are found during the flaw detection process, they can be processed in advance to avoid unnecessary subsequent inspection processes and improve inspection efficiency.

[0114] In some embodiments, the flaw detection operation includes scanning the inspection area, recording the inspection data, and identifying and processing weld defects.

[0115] According to the shape, size and structural characteristics of the welding assembly 100, select a suitable scanning method. For the welding of the end plate and the side of the battery cell 20 with a hemming structure, the shape is regular, and the linear scanning method can be used. The probe moves parallel to the center line and both sides of the weld. The scanning interval is generally not greater than the probe chip size to ensure full coverage of the detection area. For circular or annular welds, the circumferential scanning method can be used, and the probe moves around the circumference of the weld.

[0116] In order to more accurately detect defects in different directions, in addition to conventional scanning methods, multi-angle scanning is also required. For example, for welds that may have inclined cracks, use an oblique probe to scan at different angles. Generally, probes with different refraction angles such as 30°, 45°, and 60° can be selected to increase the probability of detecting defects.

[0117] Record the characteristics of the ultrasonic reflection signal in detail, including the amplitude, position, time, etc. of the signal. The signal amplitude reflects the size and nature of the defect. The signal position can be determined by the coordinate position of the probe in the detection area. For a scanning device with a scale, the position of the defect can be recorded more accurately. The signal time is related to the depth of the defect, and the depth of the defect can be calculated based on the ultrasonic propagation time and the sound speed in the material. It can also record various parameters used in the scanning process, such as the frequency and refraction angle of the probe, and the gain and suppression of the ultrasonic flaw detector.

[0118] According to the recorded ultrasonic reflection signal characteristics, combined with relevant standards and experience, weld defects are identified. For example, for crack defects, their reflection signals usually have sharp peaks and large signal amplitudes, and the signal changes significantly when scanning at different angles; while the reflection signals of porosity defects are relatively smooth and the amplitude is relatively small. By analyzing the waveform, amplitude, and dynamic changes of the signal, the type, size, and location of the defect can be determined. The ultrasonic signal obtained by the detection can also be compared with the standard defect map. The standard map is drawn based on a large amount of actual detection data and test results, and contains typical signal characteristics of various common defects. By comparing the maps, defects in the weld can be more intuitively identified and their approximate nature and severity can be determined.

[0119] For some minor defects, such as small-sized pores, slag inclusions, etc., if they do not affect the performance of the welding assembly 100, they can be retained for observation. In the subsequent use process, these defects are regularly monitored to observe whether they expand or change.

[0120] Severe defects beyond the allowable range, such as through cracks and lack of fusion, must be dealt with in a timely manner. The treatment method can select a suitable repair process according to the type and location of the defect, such as using welding repair to repair the crack. During the repair process, the welding process regulations must be strictly followed to ensure the quality of the repair. After the repair, the repaired part must be re-detected to verify the repair effect.

[0121] In the above scheme, the scanning process can fully cover the inspection area, and the recorded inspection data can provide a basis for subsequent analysis and processing. Identifying and processing weld defects can timely discover and solve potential quality problems, further improving the integrity and effectiveness of the weld quality inspection of the welding assembly 100.

[0122] like Figure 5 As shown, in some embodiments, the steps of identifying and addressing weld defects include:

[0123] S41. Calculate the size, depth and type of the defect based on the amplitude, position and waveform characteristics of the ultrasonic reflection signal.

[0124] The defect size can be calculated using the amplitude method and the half-wave height method. The amplitude method estimates the defect size based on the relationship between the amplitude of the ultrasonic reflection signal and the defect size. Generally speaking, the larger the reflection signal amplitude, the larger the defect size may be. Through a large number of experiments and theoretical analysis, a corresponding relationship curve or empirical formula between the reflection signal amplitude and the defect size under different types of welds and materials is established. The half-wave height method is suitable for defects with regular shapes. In ultrasonic testing, half of the reflection signal amplitude is used as the measurement reference. By moving the probe, two positions where the reflection signal amplitude is half of the maximum value are found. The distance between these two positions is the size of the defect in the direction of probe movement. For defects in three-dimensional space, measurements must be taken from different directions to more accurately determine their actual size.

[0125] S42. Determine whether the defect exceeds the defect threshold according to the acceptance level in the inspection standard.

[0126] The inspection standards generally classify weld quality into different acceptance levels, such as Level I, Level II, and Level III, and each level corresponds to a different allowable range of defects. Defect thresholds include defect size thresholds, quantity thresholds, etc. For example, for a certain level of weld, it is stipulated that the maximum diameter of a single pore shall not exceed a certain value, and the number of pores per unit length shall not exceed a specified number, etc. The defect size, depth, type, and other information calculated are compared one by one with the defect threshold of the corresponding acceptance level.

[0127] S43. If the defect exceeds the acceptance criteria, output repair suggestion instructions.

[0128] When it is determined that the defects exceed the acceptance criteria, it is necessary to formulate a corresponding repair plan based on the specific conditions such as the type, location, and size of the defects. For crack defects, the method of grinding to remove the cracks and then re-welding is generally used for repair. During the grinding process, it is necessary to ensure that the cracks are completely removed, and then select appropriate welding materials and welding processes for repair welding. For pores and slag inclusion defects, if the defects are small and concentrated, the local excavation method can be used; if the defects are numerous and scattered, the entire weld area may need to be re-welded.

[0129] In the above scheme, the size, depth and type of the defect are calculated based on the amplitude, position and waveform characteristics of the ultrasonic reflection signal, so that the specific situation of the weld defect can be accurately understood; whether the defect exceeds the defect threshold is determined according to the acceptance level in the detection standard, and the severity of the defect can be objectively judged; if the defect exceeds the acceptance standard, a repair suggestion instruction is output, which provides specific guidance for repairing weld defects and helps to improve the quality and reliability of the welding assembly 100.

[0130] like Figure 6As shown, in some embodiments, after the step of comparing the ultrasonic detection area with the area threshold, the step further includes:

[0131] S50 , storing data after the detection is completed, and performing calibration and maintenance on the ultrasonic detection device 40 .

[0132] After the measurement is completed, the data is stored in the instrument's built-in memory. If necessary, the measured data can be exported to a computer for data analysis and processing. After the test is completed, turn off the equipment, organize the equipment, place each component in the corresponding slot of the special shockproof box, count each component to make sure it is not lost, and then close the box cover and tighten it. Calibrate and maintain the equipment regularly to ensure its accuracy and reliability. For example, use a standard test block to calibrate the sound velocity or thickness to ensure the accuracy of the measurement results.

[0133] In the above scheme, storing data can facilitate the subsequent tracing and analysis of the test results, providing data support for quality control and process improvement; calibrating and maintaining the ultrasonic detection device 40 can ensure the accuracy and stability of the ultrasonic detection device 40, ensure the reliability of subsequent test results, and extend the service life of the ultrasonic detection device 40.

[0134] In some embodiments, the steps of performing calibration maintenance on the ultrasonic detection device 40 include:

[0135] S51 . Use a standard test block to regularly calibrate the sound velocity and thickness measurement accuracy of the ultrasonic testing device 40 .

[0136] The standard test block is a key tool for calibrating the ultrasonic testing device 40. It has known physical properties, such as sound velocity, thickness, etc. Before calibration, a suitable standard test block should be selected according to the model of the ultrasonic testing device 40, the testing requirements, etc. The material, size, internal structure, etc. of the standard test block should be similar to the actual test object to ensure the accuracy of the calibration result.

[0137] Sound velocity calibration is an important step to ensure that the ultrasonic detection device 40 can accurately measure the depth and position of defects. The ultrasonic probe is well coupled to the standard test block, and ultrasonic waves are emitted and reflected signals are received. The actual sound velocity is calculated by measuring the propagation time of the ultrasonic wave in the standard test block and the known test block thickness. The calculated sound velocity is compared with the sound velocity currently set by the ultrasonic detection device 40. If there is a difference, the sound velocity parameter of the ultrasonic detection device 40 is adjusted to make it consistent with the actual sound velocity. During the calibration process, multiple measurements and adjustments are performed, and the average value is taken as the final calibration result to improve the accuracy of the calibration.

[0138] The thickness measurement accuracy of the ultrasonic detection device 40 is calibrated using a standard test block. The ultrasonic probe is placed at different positions of the standard test block to measure the thickness of the test block. The measurement result is compared with the known thickness value of the standard test block. If the measurement error exceeds the allowable range, the thickness measurement parameters of the ultrasonic detection device 40 are adjusted. The measurement result can be optimized by adjusting parameters such as gain and compensation until the measurement error is within the specified accuracy range. After the calibration is completed, the calibration results are recorded, including information such as the calibration date, calibration parameters, and measurement errors before and after calibration, for subsequent tracing and inquiry.

[0139] In the above scheme, the standard test block has known physical properties. By comparing and calibrating with the standard test block, the errors that may occur in the long-term use of the ultrasonic detection device 40 can be effectively eliminated, ensuring that the ultrasonic detection device 40 is always in an accurate and reliable working state, thereby improving the accuracy of weld quality detection.

[0140] like Figure 7 As shown, in the second aspect, the present application provides a weld detection system 200, which applies any of the above-mentioned detection methods. The weld detection system 200 includes an ultrasonic detection device 40 and a visual recognition device 30. The ultrasonic detection device 40 is used to scan and detect the weld; the visual recognition device 30 is used to obtain an image of the detection area of ​​the welding assembly 100.

[0141] The ultrasonic detection device 40 and the visual recognition device 30 can be connected by communication. The ultrasonic detection device 40 may include a CCD camera and an image processing unit. The collected image will be transmitted to the image processing software for analysis and processing. The ultrasonic detection device 40 is mainly composed of an ultrasonic flaw detector, an ultrasonic probe, and the like.

[0142] The weld detection system 200 may further include a data processing module 50 and a data storage module 60, or the data processing module 50 and the data storage module 60 may be integrated in the ultrasonic detection device. The data processing module 50 is used to calculate the area threshold and the ultrasonic detection area, and output the determination result; the data storage module 60 is used to store the detection data and the equipment calibration record. The detection data collected by the ultrasonic detection device 40 will be transmitted to the data processing module 50 for processing and analysis. The data processing module 50 will process the detection data according to the preset algorithm and standard, calculate the ultrasonic detection area, and compare it with the area threshold. If the ultrasonic detection area is greater than or equal to the area threshold, the weld quality is determined to be qualified; if it is less than the area threshold, the weld quality is determined to be unqualified. At the same time, the data processing module 50 will also store and manage the detection data for subsequent query and analysis.

[0143] In the above scheme, the image is obtained by the visual recognition device 30 and the ultrasonic detection area is obtained by the ultrasonic detection device 40, and the area is compared with the area threshold, that is, the size of the welding area between the second welding part 12 and the recessed bottom wall 113 and the area threshold is compared, so that it is possible to reversely infer whether the penetration depth meets the requirement, quantitatively evaluate the weld quality, and improve the accuracy of weld quality detection. Through the cooperation of various modules, a complete weld quality detection system is formed, which realizes the automation and intelligence of weld quality detection, improves the detection efficiency and accuracy, and facilitates the management and analysis of detection data.

[0144] like Figure 8 As shown, in some embodiments, the weld inspection system 200 further includes an alarm device 70, which is triggered to sound an alarm when the weld is determined to be unqualified.

[0145] The alarm device 70 may be an audible and visual alarm device, a voice alarm device, etc. The audible and visual alarm combines two signals, sound and light, and the voice alarm can play a pre-recorded voice message through a speaker to inform the operator in detail of the specific circumstances of the unqualified weld, such as the defect type and location, so that the operator can take corresponding treatment measures in time.

[0146] In the above scheme, by adding an alarm device 70 to the weld inspection system 200, the alarm device 70 is triggered to alarm when the weld is determined to be unqualified. This enables the operator to promptly know the situation of unqualified weld quality, so as to take timely measures to deal with it, avoid unqualified products from entering the next production link, improve the quality control level of the production process, and reduce the losses caused by weld quality problems.

[0147] According to some embodiments of the present application, the present application provides a detection method of an embodiment of the present application, including:

[0148] S10 , using the visual recognition device 30 to obtain an image of the inspection area of ​​the welding assembly 100 .

[0149] S20, use the ultrasonic detection device 40 to scan along the weld to obtain the ultrasonic detection area of ​​the detection area; wherein the ultrasonic detection area is the welding area between the second welding part 12 and the recessed bottom wall 113.

[0150] S30, comparing the size of the ultrasonic detection area with the area threshold; if the ultrasonic detection area is greater than or equal to the area threshold, the weld quality is determined to be qualified; if the ultrasonic detection area is less than the area threshold, the weld quality is determined to be unqualified.

[0151] The area threshold is S 0 , S 0 Satisfaction: S 0=a×L, a is the width threshold of the weld, a satisfies: 0.2mm≤a≤0.9mm, and L is the length of the weld.

[0152] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A method for detecting weld quality, characterized in that: Used to detect the welding quality of a welding assembly, the welding assembly includes a first welding part and a second welding part welded to each other, the first welding part is provided with a recessed step, a portion of the second welding part is located in the recessed step, the recessed step includes a recessed side wall and a recessed bottom wall connected to each other, the second welding part is welded to the recessed side wall and the recessed bottom wall respectively; the detection method includes: Using a visual recognition device to obtain an image of the inspection area of ​​the welding assembly; An ultrasonic detection device is used to scan along the weld to obtain an ultrasonic detection area of ​​the detection area; wherein the ultrasonic detection area is a welding area between the second welded part and the bottom wall of the recess; a weld center line of the detection area is obtained by the visual recognition device, and based on the weld center line, the ultrasonic detection device is used to scan along the weld; Comparing the ultrasonic detection area with an area threshold; If the ultrasonic detection area is greater than or equal to the area threshold, the weld quality is determined to be qualified; If the ultrasonic detection area is smaller than the area threshold, the weld quality is determined to be unqualified.

2. The method for detecting weld quality according to claim 1, characterized in that: The weld centerline is a connection interface between the recessed sidewall and the second weld part.

3. The detection method according to claim 1, characterized in that: The area threshold is S0, and S0 satisfies: S0=a×L, a is the width threshold of the weld, and a satisfies: 0.2mm≤a≤0.9mm, and L is the length of the weld.

4. The detection method according to claim 3, characterized in that: The a satisfies: 0.6mm≤a≤0.9mm.

5. The detection method according to claim 3, characterized in that: The weld center line of the detection area is obtained by the visual recognition device, and the weld length is the length of the weld along the weld center line.

6. The detection method according to any one of claims 1 to 5, characterized in that: Before the step of using a visual recognition device to obtain an image of the detection area of ​​the welding assembly, the method further includes: Ultrasonic testing equipment is used to perform flaw detection operations on the inspection area.

7. The detection method according to claim 6, characterized in that: The flaw detection operation includes scanning the inspection area, recording inspection data, and identifying and processing weld defects.

8. The detection method according to claim 7, characterized in that: The steps of identifying and treating weld defects include: Calculate the size, depth and type of defects based on the amplitude, position and waveform characteristics of the ultrasonic reflection signal; Determine whether the defect exceeds the defect threshold based on the acceptance level in the inspection standard; If the defect exceeds the acceptance criteria, output repair suggestion instructions.

9. The detection method according to claim 1, characterized in that: After the step of comparing the ultrasonic detection area with the area threshold, the following step is further performed: After the test is completed, the data is stored and the ultrasonic testing device is calibrated and maintained.

10. The detection method according to claim 9, characterized in that: The steps of calibrating and maintaining the ultrasonic detection device include: Use standard test blocks to regularly calibrate the sound velocity and thickness measurement accuracy of ultrasonic testing equipment.

11. A weld detection system, characterized in that: Applying the detection method described in any one of claims 1 to 10, the weld detection system comprises: Ultrasonic testing device, used to scan and inspect welds; A visual recognition device is used to obtain an image of an inspection area of ​​a welding assembly.

12. The weld inspection system according to claim 11, characterized in that: The weld detection system also includes an alarm device, which is triggered to sound an alarm when the weld is determined to be unqualified.

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