Battery casing-cover welding inspection system and method

Abstract

Disclosed in the present application are a battery casing-cover welding inspection system and method. The battery casing-cover welding inspection system comprises a first inspection apparatus and an upper computer, the first inspection apparatus comprising a first conveyor line, first rolling assemblies, a first inspection assembly and second inspection assemblies, wherein the first conveyor line is used for conveying a battery cell; the first rolling assemblies are located on two sides of the first conveyor line and are used for rolling a first side edge of a welding seam between a casing and an end cover of the battery cell; the first inspection assembly is located upstream of the first rolling assemblies in the conveying direction of the first conveyor line and is used for capturing a welding seam image before the first side edge is rolled; the second inspection assemblies are located downstream of the first rolling assemblies in the conveying direction of the first conveyor line and are used for capturing a welding seam image after the first side edge is rolled; and the upper computer is used for determining a welding defect of the first side edge on the basis of the welding seam image captured before the first side edge is rolled and the welding seam image captured after the first side edge is rolled.

Description

Battery shell cover welding detection system and method

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application No. 202410162455.7, filed on February 5, 2024, entitled “Battery Shell Cover Welding Detection System and Method,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present application relates to the field of battery technology, and in particular to a battery shell cover welding detection system and method. Background Art

[0004] Battery cells are widely used in electronic devices such as mobile phones, laptops, electric bicycles, electric cars, electric airplanes, electric boats, electric toy cars, electric toy boats, electric toy airplanes, and power tools. Battery cells can include nickel-cadmium battery cells, nickel-metal hydride battery cells, lithium-ion battery cells, and secondary alkaline zinc-manganese battery cells.

[0005] Welding defects are common during the welding process between the battery cell shell and end cap. Improving the accuracy of welding defect detection has become an urgent problem that needs to be solved.

[0006] Summary of the Invention

[0007] The embodiments of the present application provide a battery shell cover welding detection system and method, which can improve the detection accuracy of battery cell welding defects.

[0008] In the first aspect, an embodiment of the present application provides a battery shell cover welding detection system, including a first detection device and a host computer, the first detection device including a first conveyor line, a first rolling assembly, a first detection assembly, and a second detection assembly, the first conveyor line is used to convey battery cells; the first rolling assembly is located on both sides of the first conveyor line, and is used to roll the first side of the weld between the shell and the end cover of the battery cell; the first detection assembly is located upstream of the first rolling assembly along the conveying direction of the first conveyor line, and the first detection assembly is used to capture the image of the weld before rolling the first side; the second detection assembly is located downstream of the first rolling assembly along the conveying direction of the first conveyor line, and the second detection assembly is used to capture the image of the weld after rolling the first side; wherein, the host computer is used to determine the welding defect of the first side based on the image of the weld before rolling the first side and the image of the weld after rolling the first side.

[0009] In the above scheme, after the battery cell shell and end cap are welded, the battery cell is placed on a first conveyor line. The conveyance of the first conveyor line enhances the degree of automation of detection, thereby improving detection efficiency. The first side of the weld is rolled by a first rolling assembly. Rolling can improve the sealing of the weld, which helps to improve the mechanical strength of the weld and reduce looseness or cracks in the weld. Before rolling, the first inspection assembly captures an image of the first weld before rolling. After rolling, the second inspection assembly captures an image of the second weld after rolling. This allows for more comprehensive weld detection, thereby improving the accuracy of welding defect detection and the reliability of the battery cell.

[0010] In some embodiments, the second detection component includes a structured light camera, a planar light source and an annular light source. The structured light camera is arranged on both sides of the first conveyor line to capture the image of the weld after the first side is rolled; the planar light source is arranged on both sides of the first conveyor line to illuminate the first side of the weld; the annular light source is arranged on both sides of the first conveyor line to illuminate the R corner of the weld.

[0011] In the above scheme, a 3D image of the weld of the battery cell can be captured by a structured light camera, and then the optical machine of the structured light camera is turned off, the plane light source is turned on, and the 2D camera in the structured light camera is used to capture the first captured image; then the plane light source is turned off, the ring light source is turned on, and the 2D camera of the structured light camera is used to capture the second captured image. The first captured image is synthesized with the second captured image to obtain a 2D image of the weld with normal grayscale, thereby controlling the overexposure of the R angle of the battery cell, preventing overexposure to a certain extent, and further improving the detection accuracy of battery cell defects.

[0012] In some embodiments, the planar light source includes a first light source and a second light source, wherein the light emitting surface of the first light source is used to face the shell of the battery cell; the second light source is arranged perpendicular to the first light source, and the light emitting surface of the second light source is used to face the end cover of the battery cell.

[0013] In the above solution, the first light source can illuminate the portion of the battery cell shell close to the first side, and the second light source can illuminate the portion of the battery cell end cap close to the first side, which can more comprehensively illuminate the first side and improve the clarity of the captured image.

[0014] In some embodiments, two annular light sources are provided on each side of the first conveying line, and the two annular light sources are respectively provided upstream and downstream of the planar light source in the conveying direction along the first conveying line.

[0015] In the above scheme, by setting two annular light sources on each side of the first conveyor line, the four R corners of the weld can be illuminated, thereby controlling the overexposure of the four R corners of the weld of the battery cell, and further improving the detection accuracy of battery cell defects.

[0016] In some embodiments, the first detection component includes a first slide rail and a first laser camera, and the first slide rail is arranged parallel to the conveying direction of the first conveyor line; the first laser camera is slidably connected to the first slide rail, and the first laser camera is used to capture the image of the weld before rolling the first side.

[0017] In the above solution, the first laser camera moves along the first slide rail to capture the weld image of the first side before rolling, which can cover the entire first side before rolling and improve detection efficiency.

[0018] In some embodiments, the battery shell cover welding detection system also includes a second detection device, the second detection device includes a second conveyor line, a second rolling assembly, a third detection assembly and a fourth detection assembly, the second conveyor line is used to convey battery cells; the second rolling assembly is located on both sides of the second conveyor line, and is used to roll the second side of the weld of the battery cell shell and the end cover; the third detection assembly is located upstream of the second rolling assembly along the conveying direction of the second conveyor line, and the third detection assembly is used to capture the image of the weld before rolling the second side; the fourth detection assembly is located downstream of the second rolling assembly along the conveying direction of the second conveyor line, and the fourth detection assembly is used to capture the image of the weld after rolling the second side; wherein, the host computer is used to determine the welding defects of the second side based on the image of the weld before rolling the second side and the image of the weld after rolling the second side.

[0019] In the above scheme, after the shell and end cover of the battery cell are welded, the battery cell is placed on the second conveyor line. The conveyance of the second conveyor line enhances the degree of automation of detection, thereby improving detection efficiency. The second side of the weld is rolled by the second rolling assembly. Rolling can improve the sealing of the weld. Rolling helps to improve the mechanical strength of the weld and reduce looseness or cracks in the weld. Before rolling, the weld image of the second side is captured by the third detection assembly before rolling. After rolling, the weld image of the second side is captured by the fourth detection assembly after rolling. The weld is detected more comprehensively, thereby improving the accuracy of welding defect detection. The welding defect detection of the first side and the second side is respectively performed by the first conveyor line and the second conveyor line, thereby improving the integrity of the weld defect detection between the shell and the end cover.

[0020] In some embodiments, the length of the first side is shorter than the length of the second side. Since the first side is shorter than the second side, the structured light camera and the light source can more easily cover the welding position.

[0021] In some embodiments, the third detection component includes a second slide rail and a second laser camera, and the second slide rail is arranged parallel to the conveying direction of the second conveyor line; the second laser camera is slidably connected to the second slide rail, and the second laser camera is used to capture the image of the weld before rolling the second side.

[0022] In the above solution, the second laser camera moves along the second slide rail to capture the weld image of the second side before rolling, which can cover the entire second side before rolling and improve detection efficiency.

[0023] In some embodiments, the fourth detection component includes a third slide rail and a third laser camera, and the third slide rail is arranged parallel to the conveying direction of the second conveyor line; the third laser camera is slidably connected to the third slide rail, and the third laser camera is used to capture the image of the weld after the second side is rolled.

[0024] In the above solution, the third laser camera moves along the third slide rail to capture the image of the weld bead after rolling on the third side, which can cover the entire third side after rolling and improve the detection efficiency.

[0025] In a second aspect, an embodiment of the present application further provides a battery case cover welding detection method, which is applied to the battery case cover welding detection system of any of the above embodiments, and the detection method includes:

[0026] transporting battery cells via a first conveyor line;

[0027] When the battery cell arrives at the first pre-roller inspection station, the first inspection component captures an image of the first side of the weld bead between the battery cell housing and the end cover before rolling.

[0028] When the battery cell reaches the first rolling station, rolling the first side of the weld bead by the first rolling assembly;

[0029] When the battery cell reaches the inspection station after the first roller, the second inspection component captures the image of the weld bead after the first side is rolled;

[0030] The host computer detects the weld bead image of the first side before rolling and the weld bead image of the first side after rolling to obtain the welding defect detection result of the first side.

[0031] In the above solution, after the battery cell shell and end cap are welded, the battery cell is placed on a first conveyor line. The conveying process on the first conveyor line enhances the automation of inspection, thereby improving inspection efficiency. The first side of the weld is rolled by a first rolling assembly. This rolling process improves the seal of the weld, helps to increase the mechanical strength of the weld, and reduces looseness or cracks in the weld. Before rolling, the first inspection assembly captures an image of the weld before rolling. After rolling, the second inspection assembly captures an image of the weld after rolling. This allows for more comprehensive weld inspection, thereby improving the accuracy of weld defect detection.

[0032] In some embodiments, the step of capturing an image of the weld bead after rolling the first side by the second detection component includes:

[0033] Acquire a 3D image of the first side of the weld bead using a structured light camera and a 2D camera;

[0034] Shielding the light machine, lighting the planar light source, and acquiring a first captured image of the first side through the 2D camera;

[0035] Turn off the planar light source, turn on the ring light source, and acquire a second captured image of the first side using the 2D camera;

[0036] The first captured image and the second captured image are synthesized to obtain a 2D image of the first side of the weld bead.

[0037] In the above scheme, a 3D image of the weld of the battery cell can be captured by a structured light camera, and then the optical machine of the structured light camera is turned off, the plane light source is turned on, and the 2D camera in the structured light camera is used to capture the first captured image; then the plane light source is turned off, the ring light source is turned on, and the 2D camera of the structured light camera is used to capture the second captured image. The first captured image is synthesized with the second captured image to obtain a 2D image of the weld with normal grayscale, thereby controlling the overexposure of the R angle of the battery cell, preventing overexposure to a certain extent, and further improving the detection accuracy of battery cell defects.

[0038] The above description is only an overview of the technical solution of this application. In order to more clearly understand the technical means of this application, it can be implemented in accordance with the contents of the specification. In order to make the features and advantages of this application more obvious and easy to understand, the specific implementation methods of this application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments of the present application. 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.

[0040] FIG1 is a schematic structural diagram of a battery cell according to some embodiments of the present application;

[0041] FIG2 is a schematic structural diagram of a first detection device according to some embodiments of the present application;

[0042] FIG3 is a schematic structural diagram of a battery cell and a second detection component in some embodiments of the present application;

[0043] FIG4 is a schematic structural diagram of a battery cell and part of a second detection component in some embodiments of the present application;

[0044] FIG5a is a schematic diagram of a 3D image of a first side in some embodiments of the present application;

[0045] FIG5 b is a schematic diagram of a first captured image according to some embodiments of the present application;

[0046] FIG5c is a schematic diagram of a second captured image according to some embodiments of the present application;

[0047] FIG5 d is a schematic diagram of a synthesis of a first captured image and a second captured image according to some embodiments of the present application;

[0048] FIG6 is a schematic structural diagram of a first detection component and a battery cell in some embodiments of the present application;

[0049] FIG7 is a schematic structural diagram of the first detection assembly and the battery cell from another angle in some embodiments of the present application;

[0050] FIG8 is a schematic structural diagram of a second detection device according to some embodiments of the present application;

[0051] FIG9 is a side view of a battery cell and a third detection assembly / a fourth detection assembly according to some embodiments of the present application;

[0052] FIG10 is a schematic flow chart of a detection method according to some embodiments of the present application;

[0053] FIG11 is a flow chart of detection methods according to other embodiments of the present application.

[0054] Explanation of the accompanying drawings: 20, battery cell; 211, first side; 212, second side; 22, shell; 21, end cover; 23, electrode assembly; 26, electrode terminal; 100, first detection device; 11, first conveyor line; 12, first detection assembly; 121, first slide rail; 122, first laser camera; 123, third support member; 124, first bottom plate; 125, vertical slide rail; 13, first rolling assembly; 14, second detection assembly; 141, structured light camera; 142, plane light source; 143, ring light source; 144, first light source; 145, second Light source; 146, first support member; 147, connecting member; 148, second support member; 149, adjusting member; 300, second detection device; 31, second conveyor line; 32, third detection assembly; 321, second slide rail; 322, second laser camera; 33, second rolling assembly; 34, fourth detection assembly; 341, third slide rail; 342, third laser camera; S11, detection station before the first roller; S12, detection station after the first roller; S21, detection station before the second roller; S22, detection station after the second roller, X, conveying direction; Y, vertical direction. DETAILED DESCRIPTION

[0055] The following detailed description of the embodiments of the present application is provided in conjunction with the accompanying drawings and examples. The following detailed description of the embodiments and the accompanying drawings are used to illustrate the principles of the present application, but are not intended to limit the scope of the present application, i.e., the present application is not limited to the described embodiments.

[0056] In the description of this application, it should be noted that, unless otherwise specified, "multiple" means more than two; the terms "upper", "lower", "left", "right", "inside", "outside", etc., indicating directions or positional relationships, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on this 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 perpendicular, but is within the allowable error range. "Parallel" is not strictly parallel, but is within the allowable error range.

[0057] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0058] 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.

[0059] In this application, battery cells may include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries, etc., and the embodiments of this application do not limit this. Battery cells may be cylindrical, flat, rectangular, or other shapes, etc., and the embodiments of this application do not limit this. Battery cells are generally divided into three types based on the packaging method: cylindrical battery cells, prismatic battery cells, and soft-pack battery cells, and the embodiments of this application do not limit this.

[0060] A battery cell includes an electrode assembly and an electrolyte. The electrode assembly consists of a positive electrode sheet, a negative electrode sheet, and a separator. A battery cell primarily operates by the movement of metal ions between the positive and negative electrode sheets. The positive electrode sheet comprises a positive current collector and a positive active material layer. The positive active material layer is coated on the surface of the positive current collector. The current collector uncoated with the positive active material layer protrudes from the current collector coated with the positive active material layer. The current collectors uncoated with the positive active material layer, when stacked, serve as the positive electrode tabs. For lithium-ion batteries, for example, the positive current collector can be made of aluminum, and the positive active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide. The negative electrode sheet comprises a negative current collector and a negative active material layer. The negative active material layer is coated on the surface of the negative current collector. The current collector uncoated with the negative active material layer protrudes from the current collector coated with the negative active material layer. The current collectors uncoated with the negative active material layer, when stacked, serve as the negative electrode tabs. The negative current collector can be made of copper, and the negative active material can be carbon, silicon, or other materials. The material of the isolation film may be PP (polypropylene) or PE (polyethylene), etc. In addition, the electrode assembly may be a wound structure or a laminated structure, but the embodiments of the present application are not limited thereto.

[0061] The battery cells disclosed in the embodiments of this application can be used, but are not limited to, in electrical devices such as vehicles, ships, or aircraft. A power supply system comprising the battery cells and batteries disclosed in this application can be used to improve the stability of battery performance and battery life.

[0062] Please refer to Figure 1, which is a schematic diagram of the exploded structure of a battery cell 20 provided in some embodiments of the present application. A battery cell 20 refers to the smallest unit that makes up a battery. The battery cell 20 includes an end cap 21, a shell 22, an electrode assembly 23, and other functional components. The end cap 21 refers to a component that covers the opening of the shell 22 to isolate the internal environment of the battery cell 20 from the external environment. Without limitation, the shape of the end cap 21 can be adapted to the shape of the shell 22 to match the shell 22. Optionally, the end cap 21 can be made of a material with a certain hardness and strength (such as aluminum alloy). In this way, the end cap 21 is less likely to deform when squeezed or collided, so that the battery cell 20 can have higher structural strength and improved safety performance. Functional components such as electrode terminals 26 can be provided on the end cap 21. The electrode terminal 26 can be used to electrically connect to the electrode assembly 23 to output or input electrical energy from the battery cell 20. In some embodiments, the end cap 21 may also be provided with a pressure relief mechanism for releasing the internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold value. The end cap 21 may also be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this embodiment of the present application does not impose any special restrictions on this. In some embodiments, an insulating member may also be provided on the inner side of the end cap 21. The insulating member may be used to isolate the electrical connection components in the housing 22 from the end cap 21 to reduce the risk of short circuits. Exemplary, the insulating member may be plastic, rubber, etc.

[0063] The housing 22 is a component that cooperates with the end cap 21 to form the internal environment of the battery cell 20. The formed internal environment can be used to accommodate the electrode assembly 23, electrolyte, and other components. The housing 22 and the end cap 21 can be independent components. An opening can be provided in the housing 22, and the end cap 21 is placed over the opening to form the internal environment of the battery cell 20. In some examples, the housing 22 is a hollow structure with an opening on one side, and the end cap 21 is a single end cap that covers the opening of the housing 22. In other examples, the housing 22 is a hollow structure with openings on both sides, and there are two end caps 21, each of which covers the two openings of the housing 22. Without limitation, the end cap 21 and the housing 22 can also be integrated. Specifically, the end cap 21 and the housing 22 can form a common connection surface before other components are inserted into the housing. When the interior of the housing 22 needs to be encapsulated, the end cap 21 is placed over the housing 22. Specifically, the shell 22 is cylindrical and can be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiment of the present application does not impose any special restrictions on this.

[0064] During the welding process between the battery cell shell and end cap, defects such as weld penetration, weld breakage, residual slag, and cold welds can easily occur due to improper laser power adjustment or impurities in the weld seam between the end cap and shell. Weld penetration and weld breakage can compromise the seal at the weld, potentially allowing electrolyte or other substances within the battery cell to leak, affecting normal battery operation. Welding defects can also degrade the mechanical properties of the weld, making the battery cell more susceptible to damage from vibration, impact, and other external stresses. Residual slag can affect the thermal conductivity of the weld area, making it difficult for the battery cell to effectively dissipate heat during operation, potentially causing overheating. Cold welds and other defects can reduce electrical conductivity and increase resistance in the weld area, thus affecting the performance and efficiency of the battery cell. Furthermore, welding defects can cause internal abnormalities in the battery cell, increasing safety risks. For example, weld penetration can cause an internal short circuit in the battery cell, leading to overheating or fire. Current methods for detecting weld defects between the shell and end cap have low accuracy, resulting in some defects not being detected, reducing battery reliability.

[0065] In view of this, an embodiment of the present application provides a technical solution, in which after the shell and end cover of the battery cell are welded, the battery cell is placed on a first conveyor line, and the degree of automation of the detection is enhanced by the conveyance of the first conveyor line, thereby improving the detection efficiency. The first side of the weld is rolled by a first rolling assembly, and the sealing of the weld can be improved by rolling. Rolling helps to improve the mechanical strength of the weld and reduce looseness or cracks in the weld. Before rolling, the image of the weld before rolling the first side is captured by the first detection assembly, and after rolling, the image of the weld after rolling the first side is captured by the second detection assembly. The weld is detected more comprehensively, thereby improving the accuracy of welding defect detection and improving the reliability of the battery cell.

[0066] FIG2 is a schematic diagram of the structure of the first detection device of some embodiments of the present application. As shown in FIG2, in the first aspect, the embodiment of the present application provides a battery shell cover welding detection system, including a host computer (not shown) and a first detection device 100, the first detection device 100 includes a first conveyor line 11, a first rolling assembly 13, a first detection assembly 12, and a second detection assembly 14. The first conveyor line 11 is used to convey the battery cell 20; the first rolling assembly 13 is located on both sides of the first conveyor line 11, and is used to roll the first side 211 of the weld between the shell 22 and the end cover of the battery cell 20; the first The detection component 12 is located upstream of the first rolling component 13 along the conveying direction of the first conveyor line 11, and the first detection component 12 is used to capture the weld image of the first side 211 before rolling; the second detection component 14 is located downstream of the first rolling component 13 along the conveying direction of the first conveyor line 11, and the second detection component 14 is used to capture the weld image of the first side 211 after rolling; the host computer is used to determine the welding defects of the first side 211 based on the weld image before rolling and the weld image after rolling.

[0067] The first conveyor line 11 can be a conveyor belt, roller conveyor line, chain conveyor line, or slide conveyor line. The conveyor belt can be made of materials such as rubber, plastic, or metal, and drives the battery cells 20 along the conveying direction of the first conveyor line 11. A roller conveyor line can consist of a series of rollers, which rotate to propel the battery cells 20 forward, providing smooth and continuous conveying. A chain conveyor line uses a chain drive, while a slide conveyor line uses a slide design to slide the battery cells 20 from one end to the other over a smooth surface.

[0068] A first detection assembly 12, a first roller pressing assembly 13, and a second detection assembly 14 are disposed on opposite sides of the first conveyor line 11 along its width. That is, a first detection assembly 12, a first roller pressing assembly 13, and a second detection assembly 14 are disposed sequentially along the conveying direction on each side of the first conveyor along its width. The first detection assembly 12 is located at the first roller pre-detection station S11, the first roller pressing assembly 13 is located at the first roller pressing station, and the second detection assembly 14 is located at the first roller post-detection station S12.

[0069] Taking the rectangular battery cell 20 as an example, the welding point between the shell 22 and the end cover 21 is the weld bead. The weld bead is rectangular and includes two oppositely arranged first sides 211 and two oppositely arranged second sides 212. The first side 211 and the second side 212 are connected to each other.

[0070] Because the first inspection device 100 detects welding defects on the first side 211 of the weld bead of the battery cell 20, when the battery cell 20 is placed on the first conveyor line 11, the first side 211 extends along the conveying direction of the first conveyor line 11, allowing the first side 211 to face the first inspection assembly 12, the first rolling assembly 13, and the second inspection assembly 14. When the battery cell 20 reaches the first pre-roller inspection station S11, the first conveyor line 11 stops conveying the battery cell 20, and the clamp is used to securely clamp the battery cell 20. The first inspection assembly 12 captures an image of the weld bead on the first side 211 before rolling. The battery cell 20 then continues to be conveyed along the first conveyor line 11. When the battery cell 20 reaches the first rolling station, the first conveyor line 11 stops conveying the battery cell 20, and the clamp is used to securely clamp the battery cell 20. The first rolling assembly 13 then rolls the first side 211 of the weld bead. Then the battery cell 20 continues to be conveyed through the first conveyor line 11. When the battery cell 20 reaches the first roller post-inspection station S12, the first conveyor line 11 stops conveying, and the battery cell 20 can be fixed and clamped by a clamp, and the weld image of the first side 211 after rolling is captured by the second inspection component 14.

[0071] After rolling, some weld defects on the first side 211 may be smoothed or masked, making them undetectable during the second post-roll inspection station S22. For example, if there is weld slag in the weld bead, rolling may compact the slag, making it difficult to clearly see in the image. This may result in inaccurate identification of the weld slag during weld bead inspection on the first side 211. A cold weld refers to a weld that has not completely fused to form a uniform weld. After rolling, a cold weld may be flattened by the rolling, making it difficult to distinguish in the image, which may make cold weld detection difficult. During the rolling process, the physical properties of the weld bead may change, causing some welds to break or cracks to close. Such changes may make weld fractures difficult to identify through image inspection. Some weld defects may result in gaps between welds, and rolling may compact these gaps, making them difficult to distinguish in the image. If the weld bead surface is uneven or protruding, rolling may flatten it, reducing the accuracy of surface defect detection. The first detection assembly 12 and the second detection assembly 14 may respectively include a laser camera and a structured light camera 141. The first rolling assembly 13 may include a rolling roller and a rolling adjustment mechanism. The rolling roller is a roller or drum used to apply rolling pressure. By rotating or moving, it applies a uniform force to roll the first side edge 211 of the weld bead. The rolling adjustment mechanism may be a mechanical or electric adjustment system that adjusts the position and force of the rolling roller to accommodate different models and specifications of battery cells 20, thereby improving the consistency and effectiveness of rolling.

[0072] The host computer is a computer or computer system used to process, analyze and judge the data collected from the detection equipment. Exemplarily, the first detection component 12 and the second detection component 14 are respectively connected to the host computer for communication or electrical connection. The post-weld defect detection of the battery cell 20 is completed through AI detection algorithm recognition and classification. First, a large number of defect images of various types are collected during the running machine. The algorithm engineer annotates the defect type of each defect image and provides it to the algorithm model for training. After the training is completed, the weld defect detection model is obtained. During real-time detection, the first detection component 12 transmits the weld image of the first side 211 before rolling back to the host computer, and the second detection component 14 transmits the weld image of the first side 211 after rolling back to the host computer, and the software transmits the image to the algorithm. After the image is input, through simple image preprocessing, the ROI box (region of interest) is loaded. In the ROI box, AI is used to determine the presence and type of defects in the detection main area through the mapping relationship between defects and specifications and defect characteristics.

[0073] In the above scheme, after the shell 22 of the battery cell 20 is welded to the end cover 21, the battery cell 20 is placed on the first conveyor line 11. The transportation by the first conveyor line 11 enhances the degree of automation of the detection, thereby improving the detection efficiency. The first side 211 of the weld is rolled by the first rolling assembly 13. The rolling can improve the sealing of the weld. Rolling helps to improve the mechanical strength of the weld and reduce looseness or cracks in the weld. Before rolling, the weld image of the first side 211 before rolling is captured by the first detection assembly 12, and after rolling, the weld image of the first side 211 after rolling is captured by the second detection assembly 14. The weld is detected more comprehensively, thereby improving the accuracy of welding defect detection and improving the reliability of the battery cell 20.

[0074] FIG3 is a schematic diagram of the structure of a battery cell and a second detection component in some embodiments of the present application; FIG4 is a schematic diagram of the structure of a battery cell and a portion of the second detection component in some embodiments of the present application.

[0075] Please refer to Figures 3 and 4 in combination. In some embodiments, the second detection component 14 includes a structured light camera 141, a plane light source 142 and an annular light source 143. The structured light camera 141 is arranged on both sides of the first conveyor line 11 to capture the image of the weld after the first side 211 is rolled; the plane light source 142 is arranged on both sides of the first conveyor line 11 to illuminate the first side 211 of the weld; and the annular light source 143 is arranged on both sides of the first conveyor line 11 to illuminate the R angle of the weld.

[0076] The structured light camera 141 includes an optical machine and a 2D camera. The optical machine is the projection unit of the structured light camera 141, which generates and projects light patterns or grids onto the surface of the battery cell 20 to be tested. The optical machine projection methods may include stripe projection, grid projection and coded light projection. Stripe projection is that the optical machine projects a series of parallel light stripes onto the battery cell 20 to be tested. These stripes are captured by the 2D camera after the surface of the battery cell 20 to be tested is deformed to form an image. Grid projection is that the optical machine projects a grating or grid pattern onto the battery cell 20 to be tested. The deformation of the object surface causes the projection pattern to be distorted. The 2D camera captures these deformations and calculates the three-dimensional shape of the surface of the battery cell 20 to be tested through the deformation of the pattern. Coded light projection uses a coded light source to improve the accuracy of depth measurement through the coded information of light.

[0077] The 2D camera is used to capture the deformation of the projected light pattern or grid on the surface of the battery cell 20 under test. The 2D camera is positioned at a different angle from the optical machine and focuses on the battery cell 20 under test. When the light pattern or grid is projected onto the surface of the battery cell 20 under test and deforms, the 2D camera captures these deformations and generates an image. By analyzing the deformation in the image, the system can calculate the three-dimensional coordinate information of the weld bead of the battery cell 20 under test.

[0078] The plane light source 142 is a light source installed on a plane and can generate uniform and parallel light. The ring light source 143 is a ring-shaped light source.

[0079] To facilitate testing, the battery cell 20 to be tested can be clamped and fixed using a gripper, fixture, or the like, with the end cap 21 facing downward. The structured light camera 141 and the planar light source 142 can be positioned adjacent to the first side 211 of the battery cell 20. For example, a structured light camera 141 and a planar light source 142 can be positioned adjacent to both first sides 211 of the battery cell 20, with both facing the weld bead between the housing 22 and the end cap 21. The annular light source 143 is positioned adjacent to the four rounded corners of the battery cell 20.

[0080] If a laser camera is used to capture an image of the weld after rolling on the first side 211, an image with height information is obtained by decoding the laser reflected from the detection area. The algorithm then uses the 3D image to retrieve the weld area. If the weld surface shows height information that is above or below the benchmark and outside the detection specifications, a defect is determined. The algorithm then identifies the defect type based on the defect morphology. Since the weld at the R corner of the battery cell 20 is nearly spherical, and the 3D laser camera uses the principle of triangular reflection to form an image, a total reflection light path occurs when the laser is irradiated on the spherical surface. At this point, all the light emitted by the laser is recovered by the photosensitive element, resulting in extremely high brightness in the R corner area. This causes overexposure (abnormally high brightness, with a grayscale value of 255) at the R corner. The algorithm can easily misjudge the abnormally bright area as a pinhole defect, resulting in over-detection and missed detection, which reduces the accuracy of defect detection after rolling on the first side 211.

[0081] Figure 5a is a schematic diagram of a 3D image of the first side of some embodiments of the present application; Figure 5b is a schematic diagram of a first captured image of some embodiments of the present application; Figure 5c is a schematic diagram of a second captured image of some embodiments of the present application; and Figure 5d is a schematic diagram of a synthesis of the second captured image and the second captured image in some embodiments of the present application.

[0082] As shown in Figure 5a, the present embodiment uses structured light camera 141 to capture a 3D image of the weld bead of the battery cell 20 under test. As shown in Figure 5b, the optical mechanism of structured light camera 141 is then turned off, and planar light source 142 is turned on. A first captured image is captured using the 2D camera within structured light camera 141. In this first captured image, the straight line segment (A) of the first side 211 is overexposed, while the grayscale image at the R corner (B) is normal. As shown in Figure 5c, planar light source 142 is then turned off, and annular light source 143 is turned on. A second captured image is captured using the 2D image of structured light camera 141. In this second captured image, the straight line segment (A) of the first side 211 is normal in grayscale, while the R corner (B) is overexposed. As shown in Figure 5d, the first and second images are combined to produce a 2D image of the weld bead with normal grayscale. This controls overexposure of the R corner (B) of the battery cell 20, prevents overexposure and omissions, and improves the efficiency of defect detection for battery cell 20.

[0083] In some embodiments, the planar light source 142 includes a first light source 144 and a second light source 145 , wherein the light-emitting surface of the first light source 144 is used to face the shell 22 of the battery cell 20 ; the second light source 145 is arranged perpendicular to the first light source 144 , and the light-emitting surface of the second light source 145 is used to face the end cover of the battery cell 20 .

[0084] The first light source 144 is arranged parallel to the side of the housing 22, and the second light source 145 is arranged parallel to the end cap 21. For example, one first light source 144 is arranged on the left side of the left first side 211, and another first light source 144 is arranged on the right side of the right first side 211. One second light source 145 is arranged on the lower left side of the end cap 21, and another second light source 145 is arranged on the lower right side of the end cap 21. To cover the first side 211, the lower end of the first light source 144 is arranged beyond the bottom of the housing 22, the left end of the left second light source 145 is arranged beyond the left side of the end cap 21, and the right end of the right second light source 145 is arranged beyond the right side of the end cap 21.

[0085] In the above solution, the first light source 144 can illuminate the portion of the shell 22 of the battery cell 20 close to the first side 211, and the second light source 145 can illuminate the portion of the end cover of the battery cell 20 close to the first side 211, which can more comprehensively illuminate the first side 211 and improve the clarity of the captured image.

[0086] In some embodiments, two annular light sources 143 are provided on each side of the first conveying line 11 , and the two annular light sources 143 are respectively provided upstream and downstream of the planar light source 142 in the conveying direction along the first conveying line 11 .

[0087] Exemplarily, on the left side of the first conveyor line 11, the planar light source 142 is disposed between two annular light sources 143, and the two annular light sources 143 face the two R corners of the first side edge 211 on the left side. On the right side of the first conveyor line 11, the planar light source 142 is disposed between two annular light sources 143, and the two annular light sources 143 face the two R corners of the first side edge 211 on the right side.

[0088] In the above scheme, by setting two annular light sources 143 on each side of the first conveyor line 11, the four R corners of the weld can be illuminated, thereby controlling the overexposure of the four R corners of the weld of the battery cell 20, and further improving the detection accuracy of defects in the battery cell 20.

[0089] Optionally, the planar light source 142 may be disposed at a position toward a middle area of ​​the first side 211 , so that the planar light source 142 can illuminate various areas of the first side 211 more uniformly.

[0090] In some embodiments, the second detection assembly 14 further includes a first support member 146 and a connecting member 147 . The annular light source 143 is connected to the connecting member 147 , and the connecting member 147 is engaged with the first support member 146 .

[0091] The first support member 146 can be placed vertically on the ground, and the connecting member 147 can be fixed to the upper end of the first support member 146 by a buckle. The annular light source 143 is arranged at the end of the connecting member 147 away from the first support member 146. Because the connecting member 147 is snap-fitted to the first support member 146, the connecting member 147 or the first support member 146 can be repaired or replaced separately. The snap-fit ​​position of the connecting member 147 on the first support member 146 can also be adjusted to adjust the height of the annular light source 143.

[0092] In some embodiments, the annular light source 143 is rotatably connected to the connecting member 147 .

[0093] The annular light source 143 can be connected to the connecting member 147 by rotating the ball head or the snap ring, so that the annular light source 143 can be rotated horizontally or 360 degrees relative to the connecting member 147 to adjust the illumination angle of the annular light source 143.

[0094] In some embodiments, the second detection component 14 further includes a second support member 148 and an adjustment member 149 . The second support member 148 extends along the vertical direction Y, the structured light camera 141 is connected to the adjustment member 149 , and the adjustment member 149 is movably connected to the second support member 148 along the vertical direction Y.

[0095] The second support member 148 can be provided with multiple threaded holes spaced apart along the vertical direction Y. The adjusting member 149 can be a bolt, and the adjusting member 149 can be connected to different threaded holes of the second support member 148 to adjust the height of the structured light camera 141. Alternatively, a slide rail can be provided on the second support member 148, and a slider can be provided on the adjusting member 149. The slider and the slide rail can be slidably engaged to adjust the height of the structured light camera 141. Alternatively, a buckle can be provided on the adjusting member 149, and multiple hooks can be provided along the vertical direction Y on the second support member 148. The height of the structured light camera 141 can be adjusted by engaging the buckle with different hooks.

[0096] In some embodiments, the structured light camera 141 is tilted relative to the vertical direction Y. For example, the structured light camera 141 is tilted relative to the vertical direction Y at an angle of 30 degrees, 45 degrees, or 60 degrees. The lens of the structured light camera 141 is oriented toward the first side so that the lens of the structured light camera 141 can capture both the housing 22 and the end cap 21, thereby better capturing the weld bead.

[0097] FIG6 is a schematic structural diagram of a first detection component and a battery cell according to some embodiments of the present application.

[0098] As shown in Figure 6, in some embodiments, the first detection component 12 includes a first slide rail 121 and a first laser camera 122, and the first slide rail 121 is arranged parallel to the conveying direction of the first conveyor line 11; the first laser camera 122 is slidably connected to the first slide rail 121, and the first laser camera 122 is used to capture the weld image of the first side 211 before rolling.

[0099] The first laser camera 122 can be a line scan camera. The first laser camera 122 is slidably connected to the first slide rail 121 through a bracket and other structures. The first laser camera 122 is driven to move along the first slide rail 121 by a driving member such as a motor and a cylinder. The first laser camera 122 can move from one end of the first side 211 to the other end, and continuously capture the weld image of the first side 211 before rolling.

[0100] In the above solution, the first laser camera 122 moves along the first slide rail 121 to capture the weld image of the first side 211 before rolling, which can cover the entire first side 211 before rolling, thereby improving detection efficiency.

[0101] In some embodiments, the first laser camera 122 is tilted relative to the vertical direction Y. For example, the structured light camera 141 is positioned at an angle of 30 degrees, 45 degrees, or 60 degrees relative to the vertical direction Y, and the lens of the structured light camera 141 is oriented toward the first side 211 , so that the lens of the first laser camera 122 can capture both the housing 22 and the end cap 21 , thereby better capturing the weld bead.

[0102] FIG. 7 is a schematic structural diagram of the first detection assembly and the battery cell from another angle according to some embodiments of the present application.

[0103] As shown in Figure 7, in some embodiments, the first detection component 12 also includes a third support member 123 and a first base plate 124. The first base plate 124 is arranged on the third support member 123, and the first laser camera 122 is arranged on the first base plate 124. The first laser camera 122 is inclined relative to the first base plate 124 at an angle of α1, and α1 satisfies the following conditions: 5°≤α1≤15°.

[0104] Wherein, α1 can be any value in the range of 5°-15°. For example, α1 can be 5°, 7°, 8°, 10°, 11°, 12°, 13°, 14° or 15°.

[0105] In the above solution, by tilting the first laser camera 51 at a certain angle relative to the first base plate 512, the distance between the laser head of the first laser camera 51 and the weld is lengthened, thereby avoiding the overall overexposure of the weld caused by total reflection of the light path to a certain extent.

[0106] In some embodiments, α1 satisfies the following condition: 12°≤α1≤15°. Here, α1 can be any value in the range of 12°-15°. For example, α1 can be 12°, 12.5°, 13.5°, 14.5°, or 15°. The embodiments of the present application further reduce weld overexposure.

[0107] In some embodiments, the first detection component 12 further includes a vertical slide rail 125 extending along the vertical direction Y, the vertical slide rail 125 is slidably connected to the first slide rail 121, and the first laser camera 122 is slidably connected to the vertical slide rail Y along the vertical direction Y.

[0108] FIG8 is a schematic structural diagram of a second detection device according to some embodiments of the present application.

[0109] As shown in Figure 8, in some embodiments, the battery shell cover welding detection system also includes a second detection device 300, the second detection device 300 includes a second conveyor line 31, a second rolling assembly 33, a third detection assembly 32 and a fourth detection assembly 34, the second conveyor line 31 is used to convey the battery cell 20; the second rolling assembly 33 is located on both sides of the second conveyor line 31, and is used to roll the second side 212 of the weld of the shell 22 and the end cover of the battery cell 20; the third detection assembly 32 is located upstream of the second rolling assembly 33 along the conveying direction of the second conveyor line 31, and the third detection assembly 32 is used to capture the weld image of the second side 212 before rolling; the fourth detection assembly 34 is located downstream of the second rolling assembly 33 along the conveying direction of the second conveyor line 31, and the second detection assembly 14 is used to capture the weld image of the second side 212 after rolling.

[0110] The second detection assembly 14 can be a conveyor belt, a roller conveyor line, a chain conveyor line, or a slide conveyor line. A third detection assembly 32, a second rolling assembly 33, and a fourth detection assembly 34 are provided on opposite sides of the second conveyor line 31 along its width direction. In other words, a third detection assembly 32, a second rolling assembly 33, and a fourth detection assembly 34 are provided in sequence along the conveying direction on each side of the second conveyor line 31 along its width direction. The third detection assembly 32 is located at the second roller pre-detection station S21, the second rolling assembly 33 is located at the second rolling station, and the fourth detection assembly 34 is located at the second roller post-detection station S22; wherein, the host computer is used to determine the welding defects of the second side 212 based on the weld bead image of the second side 212 before rolling and the weld bead image of the second side 212 after rolling.

[0111] Because the second inspection device 300 detects welding defects on the second side 212 of the weld bead of the battery cell 20, when the battery cell 20 is placed on the second conveyor line 31, the second side 212 extends along the conveying direction of the second conveyor line 31, allowing the second side 212 to face the third inspection assembly 32, the second rolling assembly 33, and the fourth inspection assembly 34. When the battery cell 20 reaches the second pre-rolling inspection station S21, the second conveyor line 31 stops conveying the battery cell 20, and the clamp is used to securely clamp the battery cell 20. The third inspection assembly 32 captures an image of the weld bead on the second side 212 before rolling. The battery cell 20 then continues to be conveyed along the second conveyor line 31. When the battery cell 20 reaches the second rolling station, the second conveyor line 31 stops conveying the battery cell 20, and the clamp is used to securely clamp the battery cell 20. The second rolling assembly 33 then rolls the second side 212 of the weld bead. The battery cell 20 is then conveyed further along the second conveyor line 31. When the battery cell 20 reaches the second post-roller inspection station S22, the second conveyor line 31 stops conveying, the battery cell 20 is secured by a clamp, and the fourth inspection assembly 34 captures an image of the weld after rolling the second side 212. In this embodiment of the present application, the third inspection assembly 32 captures an image of the second side 212 of the weld at the second post-roller inspection station S21 before rolling, enabling the detection of weld defects that may be masked by rolling.

[0112] In the above scheme, after the shell 22 of the battery cell 20 is welded to the end cap 21, the battery cell 20 is placed on the second conveyor line 31. The conveyance by the second conveyor line 31 enhances the degree of automation of the detection, thereby improving the detection efficiency. The second side 212 of the weld is rolled by the second rolling assembly 33. Rolling can improve the sealing of the weld, which helps to improve the mechanical strength of the weld and reduce looseness or cracks in the weld. Before rolling, the weld image of the second side 212 before rolling is captured by the third detection assembly 32, and after rolling, the weld image of the second side 212 after rolling is captured by the fourth detection assembly 34. The weld is detected more comprehensively, thereby improving the accuracy of welding defect detection. The welding defect detection of the first side 211 and the second side 212 by the first conveyor line 11 and the second conveyor line 31 respectively improves the integrity of the weld defect detection between the shell 22 and the end cap 21.

[0113] In some embodiments, the length of the first side 211 is shorter than the length of the second side 212. That is, the first side 211 is the long side of the rectangular weld bead, and the second side 212 is the short side of the rectangular weld bead. Since the first side 211 is shorter than the second side 212, the structured light camera 141 and the light source can more easily cover the welding position.

[0114] FIG. 9 is a side view of a battery cell and a third detection assembly / a fourth detection assembly according to some embodiments of the present application.

[0115] As shown in Figure 9, in some embodiments, the third detection component 32 includes a second slide rail 321 and a second laser camera 322, and the second slide rail 321 is arranged parallel to the conveying direction of the second conveyor line 31; the second laser camera 322 is slidably connected to the second slide rail 321, and the second laser camera 322 is used to capture the weld image of the second side 212 before rolling.

[0116] The second laser camera 322 can be a line scan camera. The second laser camera 322 is slidably connected to the second slide rail 321 through a bracket and other structures. The second laser camera 322 is driven to move along the second slide rail 321 by a driving member such as a motor and a cylinder. The second laser camera 322 can move from one end of the second side 212 to the other end, and continuously capture the weld image of the second side 212 before rolling.

[0117] In the above solution, the second laser camera 322 moves along the second slide rail 321 to capture the weld image of the second side 212 before rolling, which can cover the entire second side 212 before rolling, thereby improving detection efficiency.

[0118] In some embodiments, the fourth detection component 34 includes a third slide rail 341 and a third laser camera 342. The third slide rail 341 is arranged parallel to the conveying direction of the second conveyor line 31; the third laser camera 342 is slidably connected to the third slide rail 341, and the third laser camera 342 is used to capture the image of the weld after the second side 212 is rolled.

[0119] The third laser camera 342 can be a line scan camera. The third laser camera 342 is slidably connected to the third slide rail 341 through a bracket and other structures. The third laser camera 342 is driven to move along the third slide rail 341 by a motor, a cylinder and other driving parts. The third laser camera 342 can move from one end of the second side 212 to the other end, and continuously capture the image of the weld after the second side 212 is rolled.

[0120] In the above solution, the third laser camera 342 moves along the third slide rail 341 to capture the weld image of the third side after rolling, which can cover the entire third side after rolling and improve the detection efficiency.

[0121] FIG10 is a flow chart of the detection method according to some embodiments of the present application.

[0122] As shown in FIG10 , in a second aspect, an embodiment of the present application further provides a battery case cover welding detection method, which is applied to the battery case cover welding detection system of any of the above embodiments, and the detection method includes:

[0123] S10, transporting the battery cell 20 through the first conveyor line 11;

[0124] S20, when the battery cell 20 arrives at the first pre-roll inspection station S11, the first inspection assembly 12 captures an image of the weld bead of the first side 211 between the housing 22 and the end cap of the battery cell 20 before rolling;

[0125] S30, when the battery cell 20 arrives at the first rolling station, the first side edge 211 of the weld is rolled by the first rolling assembly 13;

[0126] S40, when the battery cell 20 reaches the first roller post-test station S12, the second test assembly 14 captures an image of the weld bead of the first side 211 after being rolled;

[0127] S50 , detecting the weld bead image of the first side 211 before rolling and the weld bead image of the first side 211 after rolling by the host computer to obtain a welding defect detection result of the first side 211 .

[0128] In the above scheme, after the shell 22 of the battery cell 20 is welded to the end cap 21, the battery cell 20 is placed on the first conveyor line 11. The transportation by the first conveyor line 11 enhances the degree of automation of the detection, thereby improving the detection efficiency. The first side 211 of the weld is rolled by the first rolling assembly 13. The rolling can improve the sealing of the weld, which helps to improve the mechanical strength of the weld and reduce looseness or cracks in the weld. Before rolling, the first detection assembly 12 captures the image of the weld before rolling the first side 211, and the second detection assembly 14 captures the image of the weld after rolling the first side 211. The weld is detected more comprehensively, thereby improving the accuracy of welding defect detection.

[0129] FIG11 is a flow chart of detection methods according to other embodiments of the present application.

[0130] As shown in FIG11 , in some embodiments, the step of capturing the weld image of the first side 211 after rolling by the second detection component 14 includes:

[0131] S41 , obtaining a 3D image of the first side 211 of the weld bead through the optical machine of the structured light camera 141 and the 2D camera.

[0132] S42 , shielding the light machine, lighting the planar light source 142 , and acquiring a first captured image of the first side 211 through the 2D camera.

[0133] The planar light source 142 faces the straight segment of the first side 211 . Therefore, when the planar light source 142 is turned on, the straight segment will be overexposed, and the grayscale image of the R corner position will be normal.

[0134] S43 , turning off the planar light source 142 , lighting up the annular light source 143 , and acquiring a second captured image of the first side 211 through the 2D camera.

[0135] The annular light source 143 faces the R corner of the first side 211 . Therefore, when the annular light source 143 is turned on, the R corner is overexposed, while the grayscale image of the straight line segment is normal.

[0136] S44 , synthesize the first captured image and the second captured image to obtain a 2D image of the first side 211 of the weld bead.

[0137] In the above scheme, a 3D image of the weld bead of the battery cell 20 can be captured by the structured light camera 141, and then the optical machine of the structured light camera 141 is turned off, the plane light source 142 is turned on, and the 2D camera in the structured light camera 141 is used to capture the first captured image; then the plane light source 142 is turned off, the annular light source 143 is turned on, and the 2D camera of the structured light camera 141 is used to capture the second captured image. The first captured image is synthesized with the second captured image to obtain a 2D image of the weld bead with normal grayscale, thereby controlling the overexposure of the R angle of the battery cell 20, preventing overexposure to a certain extent, and further improving the detection accuracy of defects in the battery cell 20.

[0138] According to some embodiments of the present application, the present application provides a battery shell cover welding detection system, which includes a first detection device 100 and a host computer. The first detection device 100 includes a first conveyor line 11, a first rolling assembly 13, a first detection assembly 12, and a second detection assembly 14. The first conveyor line 11 is used to convey battery cells 20; the first rolling assembly 13 is located on both sides of the first conveyor line 11, and is used to roll the first side 211 of the weld between the shell 22 and the end cover of the battery cell 20; the first detection assembly 12 ... The detection assembly 12 is located upstream of the first rolling assembly 13 along the conveying direction of the first conveyor line 11. The first detection assembly 12 is used to capture an image of the weld bead of the first side edge 211 before rolling. The second detection assembly 14 is located downstream of the first rolling assembly 13 along the conveying direction of the first conveyor line 11. The second detection assembly 14 is used to capture an image of the weld bead of the first side edge 211 after rolling. The host computer is used to determine welding defects on the first side edge 211 based on the images of the weld bead before and after rolling. The second detection assembly 14 includes a structured light camera 141, a planar light source 142, and an annular light source 143. The structured light camera 141 is arranged on both sides of the first conveyor line 11 to capture an image of the weld bead of the first side edge 211 after rolling. The planar light source 142 is arranged on both sides of the first conveyor line 11 to illuminate the first side edge 211 of the weld bead. The annular light source 143 is arranged on both sides of the first conveyor line 11 to illuminate the rounded corners of the weld bead.

[0139] 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 make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions 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 battery shell cover welding detection system, characterized in that: It includes a first detection device and a host computer, wherein the first detection device includes: A first conveying line is used to convey battery cells; a first rolling assembly, located on both sides of the first conveyor line, for rolling a first side edge of the weld between the shell and the end cover of the battery cell; a first detection assembly, located upstream of the first rolling assembly along the conveying direction of the first conveyor line, the first detection assembly being used to capture an image of the weld bead of the first side before rolling; a second detection assembly, located downstream of the first rolling assembly along the conveying direction of the first conveyor line, the second detection assembly being used to capture an image of the weld bead after rolling the first side edge; The host computer is used to determine the welding defects of the first side according to the weld bead image before the first side is rolled and the weld bead image after the first side is rolled; The second detection component includes: A structured light camera is provided on both sides of the first conveyor line, and is used to capture an image of the weld bead after rolling the first side edge; the structured light camera includes an optical machine and a 2D camera; Planar light sources are arranged on both sides of the first conveyor line to illuminate the first side of the weld bead; the structured light camera and the planar light source are arranged beside the first side of the battery cell; An annular light source is arranged on both sides of the first conveyor line to illuminate the R corner of the weld bead; the annular light source is arranged beside the R corner of the battery cell.

2. The battery case cover welding detection system according to claim 1, characterized in that: The planar light source comprises: a first light source, wherein a light emitting surface of the first light source is used to face the housing of the battery cell; The second light source is arranged perpendicular to the first light source, and the light-emitting surface of the second light source is used to face the end cover of the battery cell.

3. The battery case cover welding detection system according to claim 2, characterized in that: The first light source is arranged parallel to the side surface of the housing.

4. The battery case cover welding detection system according to claim 2, characterized in that: The second light source is configured to be arranged parallel to the end cover.

5. The battery case cover welding detection system according to claim 1, characterized in that: Two annular light sources are provided on each side of the first conveying line, and the two annular light sources are respectively provided upstream and downstream of the planar light source in the conveying direction along the first conveying line.

6. The battery case cover welding detection system according to claim 5, characterized in that: The planar light source is arranged in a middle area facing the first side.

7. The battery case cover welding detection system according to claim 1, characterized in that: The second detection component further includes: a first support member; A connecting member, the annular light source is connected to the connecting member, and the connecting member is clamped with the first supporting member.

8. The battery case cover welding detection system according to claim 7, characterized in that: The annular light source is rotatably connected to the connecting member.

9. The battery case cover welding detection system according to claim 1, characterized in that: The second detection component further includes: a second support member extending in a vertical direction; An adjusting member, the structured light camera is connected to the adjusting member, and the adjusting member is movably connected to the second supporting member along the vertical direction.

10. The battery case cover welding detection system according to claim 1, characterized in that: The structured light camera is arranged at an angle relative to the vertical direction.

11. The battery case cover welding detection system according to claim 1, characterized in that: The first detection component includes: a first slide rail, arranged parallel to a conveying direction of the first conveying line; A first laser camera is slidably connected to the first slide rail, and the first laser camera is used to capture an image of the weld bead before rolling the first side.

12. The battery case cover welding detection system according to claim 11, characterized in that: The first laser camera is arranged to be inclined relative to the vertical direction.

13. The battery case cover welding detection system according to claim 11, characterized in that: The first detection component further includes: a third support member; The first base plate is arranged on the third support member, the first laser camera is arranged on the first base plate, and the first laser camera is inclined relative to the first base plate at an angle of α1, and the α1 satisfies the following condition: 5°≤α1≤15°.

14. The battery case cover welding detection system according to claim 13, characterized in that: The α1 satisfies the following condition: 12°≤α1≤15°.

15. The battery case cover welding detection system according to claim 11, characterized in that: The first detection component also includes a vertical slide rail extending in a vertical direction, the vertical slide rail is slidably connected to the first slide rail, and the first laser camera is slidably connected to the vertical slide rail along the vertical direction.

16. The battery case cover welding detection system according to claim 1, characterized in that: The battery case cover welding detection system further includes a second detection device, which includes: The second conveyor line is used to convey battery cells; a second rolling assembly, located on both sides of the second conveyor line, for rolling the second side edges of the weld bead of the battery cell shell and the end cap; a third detection assembly, located upstream of the second rolling assembly along the conveying direction of the second conveyor line, the third detection assembly being used to capture an image of the weld bead of the second side before rolling; The fourth detection component is located at the second roller pressing component along the conveying direction of the second conveying line. Downstream of the fourth detection component, the fourth detection component is used to capture the image of the weld bead after the second side is rolled; The host computer is used to determine the welding defects of the second side according to the weld bead image of the second side before rolling and the weld bead image of the second side after rolling.

17. The battery case cover welding detection system according to claim 16, characterized in that: The length of the first side is smaller than the length of the second side.

18. The battery case cover welding detection system according to claim 16, characterized in that: The third detection component includes: a second slide rail, arranged parallel to a conveying direction of the second conveying line; A second laser camera is slidably connected to the second slide rail, and the second laser camera is used to capture an image of the weld bead before rolling the second side.

19. The battery case cover welding detection system according to claim 16, characterized in that: The fourth detection component includes: a third slide rail, arranged parallel to the conveying direction of the second conveying line; A third laser camera is slidably connected to the third slide rail, and the third laser camera is used to capture an image of the weld bead after the second side is rolled.

20. A battery shell cover welding detection method, characterized in that: Applied to the battery shell cover welding detection system according to any one of claims 1 to 19, the detection method includes: transporting the battery cells via the first conveyor line; When the battery cell arrives at the first pre-roller inspection station, the first inspection component captures an image of a weld bead of a first side of a weld bead between a shell and an end cover of the battery cell before rolling. When the battery cell reaches the first rolling station, rolling the first side of the weld bead by the first rolling assembly; When the battery cell reaches the inspection station after the first roller, the second inspection component captures an image of the weld bead after the first side is rolled; Detecting, by a host computer, the weld bead image of the first side before rolling and the weld bead image of the first side after rolling to obtain a welding defect detection result of the first side; The step of photographing the weld image after the first side is rolled by the second detection component includes: Acquire a 3D image of the first side of the weld bead using a structured light camera and a 2D camera; shielding the light engine, lighting the planar light source, and acquiring a first captured image of the first side through the 2D camera; Turn off the planar light source, light up the annular light source, and acquire a second captured image of the first side through the 2D camera; The first captured image and the second captured image are synthesized to obtain a 2D image of the first side of the weld bead.

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