Battery milling method, battery milling device, and battery production line

Abstract

A battery milling method, a battery milling device, and a battery production line. The battery milling method comprises the following steps: S610: acquiring an image of a welding seam of a battery case, and acquiring the position of a welding defect by means of the image of the welding seam; and S620: on the basis of the position of the welding defect, controlling a milling mechanism (10) to move and to mill the welding defect to form a milling groove. In the method, the position of the welding defect is acquired on the basis of the image of the welding seam, and then on the basis of the position of the welding defect, the milling mechanism (10) is controlled to mill the welding defect, to prepare for subsequent filler wire welding, so that a defective battery (B) with a welding defect is repaired, thereby improving the yield of battery production. The battery case of the defective battery (B) is automatically milled by means of the battery milling device and the battery production line, thereby improving the milling efficiency and the milling quality.

Description

Battery milling method, battery milling equipment and battery production line CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on the application with CN application number 202410184080.4 and application date February 19, 2024, and claims its priority. The disclosed content of the CN application is hereby introduced as a whole into this application. Technical Field

[0002] The present application relates to the field of battery manufacturing technology, and in particular to a battery milling method, a battery milling device and a battery production line. Background Art

[0003] The battery includes a battery case and an electrode assembly and an electrolyte disposed in the battery case. The electrode assembly and the electrolyte are both contained in the battery case. The battery case includes a shell body and a top cover, which is welded to the shell body to seal the battery case.

[0004] Welding defects are prone to occur when welding the top cover and the shell body, thus affecting the yield rate of battery production. Summary of the Invention

[0005] In view of the above problems, the present application provides a battery milling method, a battery milling device and a battery production line to improve the yield rate of battery production.

[0006] In a first aspect, the present application provides a battery milling method, comprising the following steps: obtaining an image of the weld of the battery shell and obtaining the position of the welding defect through the image of the weld, and controlling the movement of the milling mechanism according to the position of the welding defect and milling the welding defect to form a milling groove.

[0007] The battery milling method of the embodiment of the present application obtains the location of the welding defect based on the image of the weld seam, and then controls the milling mechanism to mill the welding defect based on the location of the welding defect, preparing for subsequent wire filler welding, so that defective batteries with welding defects can be repaired, thereby improving the yield rate of battery production. In addition, the battery milling method of the embodiment of the present application uses a milling mechanism to automatically mill the battery casing of the defective battery, which improves milling efficiency compared to manual milling and also forms higher-quality milling grooves.

[0008] In some embodiments, obtaining an image of the weld of the battery shell and obtaining the location of the welding defect through the image of the weld includes: obtaining at least two images of at least two welds of the battery shell and determining whether both of the at least two welds have welding defects; if both of the at least two welds have welding defects, obtaining the locations of the at least two welding defects based on the at least two images.

[0009] The battery milling method of the embodiment of the present application obtains images of all welds of the battery shell before milling, and then analyzes the image of each weld to determine whether there are welding defects. If there are welding defects, the positions of all welding defects are recorded, and then in the subsequent process, the milling mechanism is controlled to mill all welding defects in sequence. This avoids the need to obtain images interspersed between multiple milling operations, which causes interruption of the milling operation of the milling mechanism, thereby improving efficiency.

[0010] In some embodiments, controlling the movement of the milling mechanism according to the position of the welding defect and milling the welding defect includes: controlling the milling mechanism to sequentially mill the welding defects of at least two welds.

[0011] After acquiring images of all welds, the battery milling method of the embodiment of the present application controls the milling mechanism to sequentially mill the welding defects of at least two welds, thereby making the milling action of the milling mechanism continuous and improving operating efficiency.

[0012] In some embodiments, after controlling the milling mechanism to mill a welding defect of one weld seam, the battery is rotated to change the position of the battery relative to the milling mechanism and the milling mechanism is controlled to mill a welding defect of another weld seam of the battery.

[0013] The battery milling method of an embodiment of the present application controls the milling mechanism to mill the welding defect of one weld, rotates the defective battery to change the position of the defective battery relative to the milling mechanism and controls the milling mechanism to mill the welding defect of another weld of the battery shell. The position of the defective battery can be flexibly adapted to the milling work of the milling mechanism, thereby improving efficiency.

[0014] In some embodiments, acquiring an image of a weld of the battery casing includes acquiring an image of the weld using a vision camera.

[0015] The battery milling method of the embodiment of the present application uses a visual camera to obtain images of the weld, which has high detection efficiency and can improve the accuracy of obtaining the location of welding defects.

[0016] In some embodiments, the battery milling method further includes: obtaining the length of the welding defect in the extension direction of the weld through an image of the weld, and obtaining the length of the milling groove according to the length of the welding defect, and controlling the milling mechanism to mill according to the length of the milling groove.

[0017] The battery milling method of the embodiment of the present application obtains the length of the welding defect through the image of the weld, and calculates the length of the milling groove based on the length of the welding defect, so that the length of the milling groove is adapted to the length of the welding defect, thereby achieving all-round repair of the welding defect and improving the repair quality.

[0018] In some embodiments, the length of the milling groove is greater than the length of the welding defect. Setting the length of the milling groove to be greater than the length of the welding defect allows the milling groove to completely cover the welding defect, preventing the welding defect from remaining and improving the repair quality.

[0019] In some embodiments, the length of the milling groove is 4 mm to 16 mm. Setting the length of the milling groove within the above range can ensure that welding defects are covered while preventing the milling of locations without welding defects due to the milling groove being too long, thereby milling through the battery housing.

[0020] In some embodiments, the battery milling method further includes testing the sealing of the battery housing before acquiring an image of the weld of the battery housing. Before acquiring an image of the weld, the sealing of the battery housing is tested. If the sealing of the battery housing does not meet the requirements, the battery is directly rejected, eliminating the subsequent image acquisition and milling processes and improving overall work efficiency. If the sealing of the battery housing meets the requirements, the subsequent image acquisition and milling steps are continued.

[0021] In some embodiments, the battery milling method further comprises: detecting the sealing of the battery housing during the milling process, and if leakage of the battery housing is detected during the milling process, rejecting the battery.

[0022] In some embodiments, testing the sealing of the battery casing during the milling process includes performing a positive pressure test on the battery casing. Positive pressure testing maintains the pressure of the battery casing of the defective battery to detect whether the battery cell is leaking, which has a high detection accuracy.

[0023] In some embodiments, the welding defect includes at least one of a forming defect and a connection defect.

[0024] In some embodiments, the forming defect includes at least one of a popping point defect, a pinhole defect, a pit defect, and a shrinkage cavity defect.

[0025] In some embodiments, the connection defects include cracks and / or undercuts.

[0026] In a second aspect, the present application provides a battery milling device, comprising an image acquisition mechanism, a milling mechanism and a controller, wherein the image acquisition mechanism is configured to acquire an image of the weld of the battery shell, the milling mechanism is configured to mill, the controller is electrically connected to the image acquisition mechanism and the milling mechanism, and the controller is configured to acquire the position of the welding defect according to the image of the weld acquired by the image acquisition mechanism and through the image of the weld, and the controller is further configured to control the movement of the milling mechanism according to the position of the welding defect and mill the welding defect to form a milling groove.

[0027] The battery milling equipment of the embodiment of the present application obtains the location of the welding defect based on the image of the weld seam, and then controls the milling mechanism to mill the welding defect based on the location of the welding defect, preparing for subsequent wire filler welding, so that the battery with welding defects can be repaired, thereby improving the yield rate of battery production. In addition, the battery milling equipment of the embodiment of the present application uses the milling mechanism to automatically mill the battery casing, which improves milling efficiency compared to manual milling and also forms higher-quality milling grooves.

[0028] In some embodiments, the image acquisition mechanism is configured to acquire at least two images of at least two welds of the battery casing, and the controller is configured to determine whether there are welding defects in both welds based on the at least two images; if there are welding defects in both welds, the positions of the at least two welding defects are acquired based on the at least two images.

[0029] The image acquisition mechanism of the application embodiment will acquire images of all welds of the battery shell before milling, and then analyze the image of each weld to determine whether there are welding defects. If there are welding defects, the positions of all welding defects are recorded, and then in the subsequent process, the milling mechanism is controlled to mill all welding defects in sequence. This avoids the need to intersperse image acquisition between multiple milling operations, which causes interruption of the milling operation of the milling mechanism, thereby improving efficiency.

[0030] In some embodiments, the image acquisition mechanism includes a visual camera. In the embodiments of the present application, the image acquisition mechanism includes a visual camera, so that the image of the weld is acquired by the visual camera, which has high detection efficiency and can improve the accuracy of acquiring the location of the welding defect.

[0031] In some embodiments, the visual camera is configured to be movably arranged in a plane parallel to the top surface of the battery housing. The visual camera of the embodiment of the present application is configured to be movable in a plane parallel to the top surface of the battery housing. In this way, all welds can be photographed by simply controlling the visual camera to move within the plane, which is simple to operate and has a wide coverage.

[0032] In some embodiments, the battery milling equipment also includes a clamp, which includes a rotating platform and a clamping mechanism arranged on the rotating platform, the clamping mechanism is used to clamp the defective battery, and the rotating platform is rotatably arranged to drive the clamping mechanism to rotate to change the position of the defective battery.

[0033] The embodiment of the present application can facilitate the adjustment of the posture of the defective battery by setting a rotating platform, thereby realizing the milling of welding defects on different welds, which is convenient for control.

[0034] In some embodiments, the battery milling device further includes a positive pressure charging mechanism configured to perform a positive pressure test on the battery housing.

[0035] On the third aspect, the present application provides a battery production line, including a battery milling device and a battery repair welding device, wherein the battery repair welding device is used to repair the milling groove.

[0036] The battery production line in the embodiment of the present application first uses battery milling equipment to mill out the welding defects on the battery casing of the defective battery. After milling, the battery repair welding equipment then fills the milled grooves with wire. This allows defective batteries with welding defects to be repaired into qualified batteries, thereby reducing the battery scrap rate.

[0037] In some embodiments, the battery repair welding apparatus includes a wire feed mechanism configured to provide a length of welding wire based on the length of the milled slot. The wire feed mechanism provides a length of welding wire based on the length of the milled slot, thereby ensuring that the welding wire length is compatible with the length of the milled slot, thereby improving the repair welding effect.

[0038] 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

[0039] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to 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 the drawings without creative work.

[0040] FIG1 is a diagram showing the steps of a battery milling method according to some embodiments of the present application;

[0041] FIG2 is a schematic diagram of the three-dimensional structure of a battery milling device according to some embodiments of the present application;

[0042] FIG3 is a schematic diagram of the front view of a battery milling device according to some embodiments of the present application;

[0043] FIG4 is a schematic structural diagram of a battery clamp of a battery milling device according to some embodiments of the present application.

[0044] FIG5 is a schematic structural diagram of an image acquisition mechanism of a battery milling device according to some embodiments of the present application;

[0045] FIG6 is a schematic structural diagram of a positive pressure charging mechanism of a battery milling device according to some embodiments of the present application;

[0046] FIG7 is a schematic structural diagram of a milling mechanism according to some embodiments of the present application.

[0047] In the drawings, the drawings are not drawn to scale.

[0048] Marking Description:

[0049] Milling mechanism 10, milling head 11; fifth moving mechanism 12; sixth moving mechanism 13;

[0050] Clamp 20, clamping mechanism 21, first moving mechanism 22, rotating platform 23;

[0051] Image acquisition mechanism 30, visual camera 31, second moving mechanism 32, third moving mechanism 33;

[0052] Positive pressure charging mechanism 40, charging head 41, fourth moving mechanism 42, rotating mechanism 43;

[0053] First direction Z, second direction Y, third direction X, defective battery B. DETAILED DESCRIPTION

[0054] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0055] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0056] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present 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 herein may be combined with other embodiments.

[0057] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0058] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0059] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of 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 embodiments of the present application.

[0060] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0061] In the present application, the battery may include a lithium-ion battery, a lithium-sulfur battery, a sodium-lithium-ion battery, a sodium-ion battery or a magnesium-ion battery, etc. The embodiments of the present application are not limited to this. The battery cell includes a battery shell and an electrode assembly housed in the battery shell, and the battery shell is filled with an electrolyte. The electrode assembly is a component in the battery cell where an electrochemical reaction occurs, and the inner cavity of the battery shell forms the internal environment of the battery cell. The battery shell includes a shell body and a top cover. The top cover covers the opening of the shell body to isolate the internal environment of the battery cell from the external environment. The top cover is connected to the shell body (such as an aluminum shell) by welding. The shell body is a rectangular parallelepiped structure with an opening. The shell body includes a bottom wall and a circumferentially enclosed side wall. The opening of the shell body is arranged opposite to the bottom wall. The top cover is welded to the opening of the shell body, that is, the top cover is welded to the top of the side wall.

[0062] During research, it was discovered that welding defects can easily occur during the welding of the battery case and cover due to environmental contamination or other factors. In the current production process, defective batteries with welding defects are scrapped. This increases the number of scrapped batteries and, in turn, increases manufacturing costs.

[0063] In response to the above problems, this application proposes a battery milling method and a battery milling device. For defective batteries with welding defects, the milling mechanism is controlled to mill the location of the welding defects, preparing for the subsequent wire filling and repair welding process, so that the defective batteries with welding defects can be repaired, thereby improving the yield rate of battery production.

[0064] The battery milling method and battery milling equipment of some embodiments of the present application are described in detail below with reference to Figures 1 to 7.

[0065] 1 , a battery milling method according to some embodiments of the present application is used to mill welding defects of a defective battery, comprising the following steps:

[0066] S610, acquiring an image of a weld of the battery housing and obtaining a location of a welding defect through the image of the weld; and

[0067] S620: Control the movement of the milling mechanism according to the position of the welding defect and mill the welding defect to form a milling groove.

[0068] The weld of the battery case refers to the joint formed by welding the edge of the top cover and the edge of the shell body. In some embodiments, the weld of the battery case is located on the top surface. In other embodiments, the weld of the battery case is located on the side. The battery milling method of the embodiments of the present application is not limited to this. For a square battery case, its welds include four welds arranged in sequence in the circumferential direction. Then, the four welds can be located on the side of the battery case or on the top surface of the battery case. In some embodiments, acquiring images of the welds of the battery case includes first acquiring images of all welds of the battery case before milling, acquiring the locations of all welding defects based on the images of all welds, and then controlling the milling mechanism to mill each welding defect in turn. For example, for a square battery case, images of four welds are acquired before milling. In other embodiments, acquiring images of the welds of the battery case includes first acquiring an image of one weld, then controlling the milling mechanism to mill the welding defects of that weld. Then, an image of another weld is acquired, and then controlling the milling mechanism to mill the welding defects of the other weld.

[0069] It should also be noted that capturing an image of the battery case weld refers to capturing an image of the entire weld. Specifically, during the acquisition process, the visual camera is controlled to capture multiple sub-images along the extension direction of a particular weld, which are then stitched together to form a complete image of the entire weld. The weld image is then used to determine whether a weld defect exists. If a weld defect exists, the location of the weld defect is determined based on the weld image.

[0070] Controlling the movement of the milling mechanism based on the location of the weld defect involves controlling the milling mechanism to move to the weld defect location using the weld defect location as the target location. The milling mechanism is then controlled to perform milling at the weld defect location to form a milling groove. Specifically, the milling mechanism first needs to move to the weld defect location, for example, a first location in the direction of the weld defect. The milling mechanism then moves along the weld defect extension direction toward a second location and performs milling to form the milling groove.

[0071] The battery milling method of the embodiment of the present application obtains the location of the welding defect based on the image of the weld seam, and then controls the milling mechanism to mill the welding defect based on the location of the welding defect, preparing for subsequent wire filler welding, so that defective batteries with welding defects can be repaired, thereby improving the yield rate of battery production. In addition, the battery milling method of the embodiment of the present application uses a milling mechanism to automatically mill the battery casing of the defective battery, which improves milling efficiency compared to manual milling and also forms higher-quality milling grooves.

[0072] In some embodiments, the welding defect includes at least one of a forming defect and a connection defect. Among them, the forming defects include burst point defects, pinhole defects, pit defects and shrinkage defects. Connection defects include cracks and / or undercuts, wherein the burst point defects are caused by spatter (explosion) problems. There are many factors that cause spatter, such as the cleanliness of the shell body or the top cover, or the surface of the shell body or the top cover has protrusions, pores or internal bubbles, etc., which may cause burst point defects. In other words, the battery milling method provided in the embodiment of the present application can perform milling for the above welding defects to complete the repair of defective batteries.

[0073] In some embodiments, obtaining an image of the weld of the battery shell and obtaining the location of the welding defect through the image of the weld includes: obtaining at least two images of at least two welds of the battery shell and determining whether both of the at least two welds have welding defects; if both of the at least two welds have welding defects, obtaining the locations of the at least two welding defects based on the at least two images.

[0074] The battery milling method of the embodiment of the present application obtains images of all welds of the battery shell before milling, and then analyzes the image of each weld to determine whether there are welding defects. If there are welding defects, the positions of all welding defects are recorded, and then in the subsequent process, the milling mechanism is controlled to mill all welding defects in sequence. This avoids the need to obtain images interspersed between multiple milling operations, which causes interruption of the milling operation of the milling mechanism, thereby improving efficiency.

[0075] In some embodiments, controlling the movement of the milling mechanism according to the position of the welding defect and milling the welding defect includes: controlling the milling mechanism to sequentially mill the welding defects of at least two welds.

[0076] After acquiring images of all welds, the battery milling method of the embodiment of the present application controls the milling mechanism to sequentially mill the welding defects of at least two welds, thereby making the milling action of the milling mechanism continuous and improving operating efficiency.

[0077] The battery case includes multiple welds, often in different locations. For example, a square battery case includes four welds. Therefore, if at least two welds have defects, milling the defect in one weld requires milling the remaining welds.

[0078] In some embodiments, after controlling the milling mechanism to mill a welding defect of one weld, the defective battery is rotated to change the position of the defective battery relative to the milling mechanism and the milling mechanism is controlled to mill a welding defect of another weld of the battery case.

[0079] In some embodiments, referring to FIG4 , the battery milling apparatus includes a fixture 20. The fixture 20 includes a clamping mechanism 21 and a rotating platform 23. The clamping mechanism 21 is used to clamp the defective battery. At the loading station, the defective battery is clamped by the clamping mechanism 21 and held in an upright position. That is, the length of the defective battery extends along a first direction Z. After the clamping mechanism 21 moves from the loading station to the milling station, the rotating platform 23 rotates to drive the clamping mechanism 21, thereby causing the defective battery to change from an upright position to a horizontal position. Referring to FIG6 , FIG6 shows a defective battery B in a horizontal position. The horizontal position of the defective battery means that the length of the defective battery is perpendicular to the first direction Z and the second direction X, that is, the length of the defective battery extends along a third direction Y. Controlling the rotation of the rotating platform 23 can change the placement of the defective battery. Thus, after the milling mechanism completes milling of a weld defect in one weld seam, the rotating platform 23 is controlled to cause the milling mechanism to mill weld defects in other weld seams.

[0080] The battery milling method of an embodiment of the present application controls the milling mechanism to mill the welding defect of one weld, rotates the defective battery to change the position of the defective battery relative to the milling mechanism and controls the milling mechanism to mill the welding defect of another weld of the battery shell. The position of the defective battery can be flexibly adapted to the milling work of the milling mechanism, thereby improving efficiency.

[0081] In some embodiments, acquiring an image of a weld of the battery casing includes acquiring an image of the weld using a vision camera.

[0082] The visual camera is controlled to capture multiple sub-images along the extension of a weld seam. These sub-images are then stitched together to form a complete image of the entire weld seam. The weld seam image is then used to determine whether a weld defect exists. If a weld defect exists, the weld seam image is used to determine its location.

[0083] The battery milling method of the embodiment of the present application uses a visual camera to obtain images of the weld, which has high detection efficiency and can improve the accuracy of obtaining the location of welding defects.

[0084] In some embodiments, the battery milling method further includes: obtaining the length of the welding defect in the extension direction of the weld through an image of the weld, and obtaining the length of the milling groove according to the length of the welding defect, and controlling the milling mechanism to mill according to the length of the milling groove.

[0085] After acquiring an image of the weld seam, the battery milling method of the embodiment of the present application not only determines the location of the weld defect based on the weld seam image but also determines the length of the weld defect. The length of the weld defect is then used to determine the length of the milling slot. The milling mechanism is then controlled to perform milling based on the length of the milling slot. The weld defect length referred to herein refers to the size of the weld defect in the direction of extension of the corresponding weld seam.

[0086] The battery milling method of the embodiment of the present application obtains the length of the welding defect through the image of the weld, and calculates the length of the milling groove based on the length of the welding defect, so that the length of the milling groove is adapted to the length of the welding defect, thereby achieving all-round repair of the welding defect and improving the repair quality.

[0087] In some embodiments, the length of the milling groove is greater than the length of the welding defect. Setting the length of the milling groove to be greater than the length of the welding defect allows the milling groove to completely cover the welding defect, preventing the welding defect from remaining and improving the repair quality.

[0088] In some embodiments, the length of the milling groove is 4 mm to 16 mm. Setting the length of the milling groove within the above range can ensure that welding defects are covered while preventing the milling of locations without welding defects due to the milling groove being too long, thereby milling through the battery housing.

[0089] In some embodiments, the battery milling method further includes testing the sealing of the battery housing before acquiring an image of the weld of the battery housing. Before acquiring an image of the weld, the sealing of the battery housing is tested. If the sealing of the battery housing does not meet the requirements, the battery is directly rejected, eliminating the subsequent image acquisition and milling processes and improving overall work efficiency. If the sealing of the battery housing meets the requirements, the subsequent image acquisition and milling steps are continued.

[0090] To prevent the milling mechanism from milling through the battery casing when milling the location of the weld defect, in some embodiments, the battery milling method further includes: testing the sealing of the battery casing during the milling process. If leakage is detected during the milling process, the battery is rejected. In this way, if the sealing of the battery casing is detected to be unqualified during the milling process, it can be directly discarded.

[0091] In some embodiments, testing the sealing of the battery casing during the milling process includes performing a positive pressure test on the battery casing. Positive pressure testing maintains the pressure of the battery casing of the defective battery to detect whether the battery cell is leaking, which has a high detection accuracy.

[0092] In some embodiments, a charging head of the positive pressure charging mechanism is controlled to charge positive pressure into the battery casing from the battery filling port.

[0093] Specifically, the charging head is controlled to move toward the top cover of the battery housing so that the charging head is in close contact with the top cover. The charging head charges and maintains positive pressure from the battery filling port. If a battery leak is found, the battery is directly discharged for waste disposal.

[0094] With reference to Figures 2 to 6, an embodiment of the present application further provides a battery milling device, comprising an image acquisition mechanism 30, a milling mechanism 10, and a controller. The image acquisition mechanism 30 is configured to acquire an image of the weld of the battery housing. The milling mechanism 10 is configured to perform milling. The controller is electrically connected to the image acquisition mechanism 30 and the milling mechanism 10, and is configured to obtain the location of the welding defect based on the image of the weld acquired by the image acquisition mechanism 30 and the image of the weld. The controller is further configured to control the movement of the milling mechanism 10 based on the location of the welding defect and to mill the welding defect to form a milling groove.

[0095] The battery milling device of the embodiment of the present application obtains the location of the welding defect based on the image of the weld seam, and then controls the milling mechanism to mill the welding defect based on the location of the welding defect, preparing for subsequent wire filler welding, so that the battery with welding defects can be repaired, thereby reducing the battery scrap rate. In addition, the battery milling device of the embodiment of the present application uses the milling mechanism to automatically mill the battery casing, which improves milling efficiency compared to manual milling and also forms higher-quality milling grooves.

[0096] In some embodiments, the image acquisition mechanism 30 is configured to acquire at least two images of at least two welds of the battery housing. The controller is configured to determine whether both welds have welding defects based on the at least two images; if both welds have welding defects, the controller is configured to acquire the locations of the at least two weld defects based on the at least two images.

[0097] The image acquisition mechanism 30 of the embodiment of the present application will acquire images of all welds of the battery shell before milling, and then analyze the image of each weld to determine whether there are welding defects. If there are welding defects, the positions of all welding defects are recorded, and then in the subsequent process, the milling mechanism is controlled to mill all welding defects in sequence. This avoids the need to intersperse image acquisition between multiple milling operations, which causes interruption of the milling operation of the milling mechanism, thereby improving efficiency.

[0098] In some embodiments, the image acquisition mechanism 30 includes a visual camera 31. The image acquisition mechanism 30 of the embodiment of the present application includes a visual camera 31, so that the image of the weld is acquired by the visual camera 31, which has high detection efficiency and can improve the accuracy of acquiring the location of the welding defect.

[0099] In some embodiments, the visual camera 31 is configured to be movably disposed within a plane parallel to the top surface of the battery housing.

[0100] As shown in Figure 5, the image acquisition mechanism 30 includes a visual camera 31, a second moving mechanism 32, and a third moving mechanism 33. The visual camera 31 is mounted on the third moving mechanism 33, which is capable of driving the visual camera 31 to move in a first direction Z. Driven by the second moving mechanism 32, the third moving mechanism 33 moves in a second direction Y, thereby driving the visual camera 31 to move.

[0101] The top surface of the battery casing refers to the plane where the top surface of the battery casing's top cover lies. In one specific embodiment, the battery casing includes a shell body and a top cover. The top cover is positioned within an opening in the shell body, that is, the shell body encloses the top cover. A welding device then welds the top cover to the shell body from above. This ensures that all welds between the top cover and the shell body are located on the top surface of the battery casing.

[0102] When the defective battery reaches the milling station, the top surface of the defective battery is arranged parallel to the plane where the first direction Z and the second direction Y are located. Therefore, the visual camera 31 can move within this plane, which is conducive to obtaining images of all welds of the battery shell.

[0103] The visual camera 31 of the embodiment of the present application is configured to be movable in a plane parallel to the top surface of the battery shell, so that all welds can be photographed by simply controlling the visual camera 31 to move in the plane, which is simple to operate and has a wide coverage.

[0104] In other embodiments, the welds of the battery are located on the side of the battery housing. In this embodiment, the visual camera 31 needs to be moved around the battery housing circumferentially to obtain images of all welds.

[0105] In some embodiments, the battery milling device further includes a fixture 20. The fixture 20 includes a rotating platform 23 and a clamping mechanism 21 disposed on the rotating platform 23. The clamping mechanism 21 is used to clamp the defective battery. The rotating platform 23 is rotatably disposed to drive the clamping mechanism 21 to rotate to change the posture of the defective battery.

[0106] Because the battery casing of a defective battery has multiple welds extending in different directions, if welding defects exist on different welds, the defective battery needs to be rotated so that the milling mechanism 10 can mill the weld defects in different locations. Specifically, the rotation of the defective battery is achieved by controlling the rotating platform 23.

[0107] The embodiment of the present application can facilitate the adjustment of the posture of the defective battery by setting the rotating platform 23, thereby realizing the milling of welding defects on different welds, which is convenient for control.

[0108] 6 , in some embodiments, the battery milling device further includes a positive pressure charging mechanism 40. The positive pressure charging mechanism 40 is configured to perform a positive pressure test on the battery housing.

[0109] The present application also provides a battery production line comprising the aforementioned battery milling equipment and battery repair welding equipment, the battery repair welding equipment being used to repair welds on milled grooves. The battery production line of the present application embodiment first uses the battery milling equipment to mill the welding defects on the battery casing of a defective battery. After milling, the battery repair welding equipment is then used to repair the milled grooves with filler wire. This allows defective batteries with welding defects to be repaired into qualified batteries, thereby improving the battery yield rate.

[0110] In some embodiments, the battery repair welding apparatus includes a wire feed mechanism. The wire feed mechanism is configured to provide a length of welding wire based on the length of the milled slot. The wire feed mechanism provides a length of welding wire based on the length of the milled slot, thereby ensuring that the welding wire length is compatible with the length of the milled slot, thereby improving the repair welding effect.

[0111] In some embodiments, the length of the welding wire is equal to the length of the milled slot.

[0112] In order to further improve the accuracy, the embodiment of the present application uses a visual camera to obtain an image of the milling groove and obtains the length of the milling groove based on the image of the milling groove, so that the length of the welding wire is more consistent with the actual length of the milling groove.

[0113] Specifically, the battery repair welding equipment also includes a wire length detection mechanism. After the wire feeding mechanism delivers a set length of welding wire, the wire length detection mechanism detects the length of the delivered wire. If the length meets the requirement, the welding mechanism is controlled to use the wire for filler welding. If the length does not meet the requirement, the cutting mechanism is controlled to cut the wire and the wire feeding mechanism is controlled to re-feed the wire.

[0114] The structure of a battery milling device and a milling method according to a specific embodiment of the present application are described in detail below with reference to FIG. 2 to FIG. 7 .

[0115] As shown in FIG. 2 and FIG. 3 , the battery milling device of this embodiment includes a milling mechanism 10 , a clamp 20 , an image acquisition mechanism 30 and a positive pressure charging mechanism 40 .

[0116] As shown in Figure 4 , the clamp 20 includes a clamping mechanism 21, a rotating platform 23, and a first movable mechanism 22. The clamping mechanism 21 is used to clamp the battery. As shown in Figure 4 , the clamping mechanism 21 includes two opposing clamping portions that can be opened and closed to clamp or release a defective battery. Each clamping portion abuts against the large surface of a defective battery to clamp the defective battery. The clamping mechanism 21 is mounted on a rotating platform 23. The rotating platform 23 is rotatable about an axis extending along a third direction X to drive the clamping mechanism 21 to rotate and thereby change the position of the defective battery. In the state shown in Figure 4 , the clamping cavity formed between the two clamping portions extends along the first direction Z. When the defective battery is clamped by the clamping mechanism 21, the defective battery is in an upright position. In the state shown in Figure 6 , the clamping cavity formed between the two clamping portions extends along the second direction Y. When the defective battery is clamped by the clamping mechanism 21, the defective battery is in a flat position. The rotating platform 23 rotates to rotate the clamping mechanism 21 from the state shown in FIG. 4 to the state shown in FIG. 6 .

[0117] For a square-cased battery, when the defective battery is in a flat state, the long side of the defective battery extends along the second direction Y, and the short side of the defective battery extends along the first direction Z.

[0118] As shown in Figure 4, the fixture 20 also includes a first moving mechanism 22. The first moving mechanism 22 is configured to drive the rotating platform 23 to move along the third direction X. Referring to Figures 2 and 4, in the initial state, the rotating platform 23 is located at the loading position (i.e., the right end of Figure 4). After the defective battery is loaded onto the clamping mechanism 21, the rotating platform 23 first rotates to make the defective battery lie flat, and then moves along the third direction X under the drive of the first moving mechanism 22 to reach the milling position (i.e., the left end of Figure 4). At the milling position, the defective battery is clamped by the clamping mechanism 21 and is milled by the milling mechanism 10.

[0119] As shown in Figure 5, the image acquisition mechanism 30 includes a visual camera 31, a second movable mechanism 32, and a third movable mechanism 33. The visual camera 31 is used to acquire images of the weld. The second movable mechanism 32 is used to move the visual camera in a second direction Y, and the third movable mechanism 33 is used to move the visual camera 31 in a first direction Z. This allows the visual camera 31 to move omnidirectionally within the plane containing the second direction Y and the first direction Z, thereby acquiring images of the entire weld.

[0120] In other embodiments, the vision camera 31 can also achieve full coverage when capturing images of all welds by controlling the rotation of the clamping mechanism 21 and coordinating the movement of the vision camera 31. For example, after the clamping mechanism 21 reaches the milling position, the vision camera 31 starts scanning for defects in the defective battery, and the rotating platform 23 rotates to change the posture of the defective battery to cooperate with the vision camera to scan the four welds for welding defects.

[0121] As shown in Figure 6, the positive pressure charging mechanism 40 of this embodiment includes a charging head 41, a fourth moving mechanism 42 and a rotating mechanism 43. Among them, the charging head 41 is used to fit tightly against the top cover of the battery shell to perform positive pressure charging through the liquid filling port on the battery shell. The fourth moving mechanism 42 is used to drive the charging head 41 to move in the third direction X to approach or move away from the defective battery. The rotating mechanism 43 is used to drive the charging head 41 to rotate. Since the positive pressure charging mechanism 40 of this embodiment continuously detects the airtightness of the battery shell during the milling process of the battery shell. According to the above description, if there are welding defects in multiple welds, then after milling the welding defect of one weld, it is necessary to rotate the rotating platform 23 of the fixture 20 to rotate the defective battery. At this time, it is necessary to synchronously control the rotation of the rotating mechanism 43 to drive the rotation of the charging head 41 to achieve continuous detection of the positive pressure.

[0122] After the image acquisition mechanism 30 scans and locates the weld defect, the charging head 41, driven by the fourth movement mechanism 42, moves along the third direction X. The charging head 41 comes into close contact with the top cover of the defective battery. The charging head 41 charges the battery through the injection port and maintains a positive pressure of 0.2 MPa. If a defective battery is found to be leaking, it is discarded without milling.

[0123] In a specific embodiment, the battery case includes a shell body and a top cover. The top cover is arranged in the opening of the shell body, that is, the shell body covers the top cover, and then the welding device welds the top cover to the shell body from above the shell body. In this way, the weld between the top cover and the shell body is located on the top surface of the battery case. Therefore, the image acquisition mechanism 30 also acquires the image of the weld from the top surface side of the battery case. Furthermore, the milling mechanism 10 also mills the welding defects from the top surface side of the battery case. The top surface side of the battery case mentioned here refers to the top cover side of the battery case.

[0124] As shown in FIG7 , the milling mechanism 10 of this embodiment includes a milling head 11, a fifth movable mechanism 12, and a sixth movable mechanism 13. The fifth movable mechanism 12 is used to drive the milling head 11 to move in a first direction Z, and the sixth movable mechanism 13 is used to drive the milling head 11 to move in a second direction Y. This allows the milling head 11 to move within a plane parallel to the top surface of the battery housing, thereby expanding the range of movement and operation of the milling head and improving the flexibility of the milling head's milling operations.

[0125] For defective batteries that maintain normal pressure, the milling mechanism moves in the second direction Y based on the position of the weld defect fed back by the visual camera, accurately reaching the location of the weld defect. The milling head 11 then mills the weld defect, milling grooves of varying sizes depending on the size of the weld defect. If the battery is milled through, it will leak and be directly disposed of. After the weld defect is milled, the clamping mechanism 21 and the charging head 41 rotate simultaneously to mill another weld defect in the next weld.

[0126] In order to avoid milling through the battery housing, the depth of the milling groove is controlled to 1 mm.

[0127] The working process of the battery milling device of this embodiment is as follows:

[0128] The defective battery is loaded into the clamping mechanism 21 of the fixture 20. The clamping mechanism 21 clamps the defective battery and rotates 90° under the drive of the rotating platform 23. Then, it is moved to the milling position under the drive of the first moving mechanism 22.

[0129] The charging head 41 of the positive pressure charging mechanism 40 moves along the third direction X so that the charging head 41 is in close contact with the top cover of the defective battery. The charging head 41 charges and maintains pressure from the liquid filling port.

[0130] The visual camera 31 moves along the first direction Z and the second direction Y to scan the defective battery. At the same time, the clamping mechanism 21 rotates the defective battery driven by the rotating platform 23 to cooperate with the visual camera scanning and record the locations of all welding defects of the defective battery.

[0131] The milling head 11 of the milling mechanism 10 moves according to the position of the welding defect fed back by the visual camera 31 to mill the welding defect of one of the welds;

[0132] When milling is completed, if there are still welding defects on other sides of the defective battery, the clamping mechanism 21 and the charging head 41 rotate simultaneously to the side where the welding defect is located, and the milling mechanism 10 mills the welding defect;

[0133] When all welding defects are milled out, the fixture 20 returns to the loading position with the battery for unloading.

[0134] Although the present application has been described with reference to preferred embodiments, various modifications may be made thereto and components may be substituted with equivalents without departing from the scope of the present application. In particular, the various technical features described in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present application is not limited to the specific embodiments disclosed herein, but encompasses all technical solutions within the scope of the claims.

Claims

1. A battery milling method for milling welding defects of a battery, comprising the following steps: Acquire an image of a weld of the battery case and acquire a location of a welding defect through the image of the weld; and The milling mechanism is controlled to move according to the position of the welding defect and the welding defect is milled to form a milling groove.

2. The battery milling method according to claim 1, wherein: Obtaining an image of a weld of a battery shell and obtaining a location of a welding defect through the image of the weld includes: obtaining at least two images of at least two welds of the battery shell and determining whether both of the at least two welds have welding defects; if both of the at least two welds have welding defects, obtaining the locations of the at least two welding defects based on the at least two images.

3. The battery milling method according to claim 2, wherein: Controlling the movement of the milling mechanism according to the position of the welding defect and milling the welding defect includes: controlling the milling mechanism to sequentially mill the welding defects of the at least two welds.

4. The battery milling method according to claim 3, wherein: After controlling the milling mechanism to mill the welding defect of one weld seam, rotating the battery to change the position of the battery relative to the milling mechanism and controlling the milling mechanism to mill the welding defect of another weld seam of the battery.

5. The battery milling method according to claim 3 or 4, wherein: Acquiring an image of the weld of the battery case includes acquiring an image of the weld by a visual camera.

6. The battery milling method according to any one of claims 1 to 5, further comprising: The length of the welding defect in the extension direction of the weld is obtained through the image of the weld, and the length of the milling groove is obtained according to the length of the welding defect. The milling mechanism is controlled to perform milling according to the length of the milling groove.

7. The battery milling method according to claim 6, wherein: The length of the milling groove is greater than the length of the welding defect.

8. The battery milling method according to claim 7, wherein: The length of the milling groove is 4 mm to 16 mm. 9 . The battery milling method according to claim 1 , further comprising detecting the sealing of the battery casing before acquiring the image of the weld of the battery casing.

10. The battery milling method according to any one of claims 1 to 8, further comprising: The sealing of the battery housing is tested during the milling process. If leakage of the battery housing is detected during the milling process, the battery is rejected.

11. The battery milling method according to claim 10, wherein: The testing of the sealing performance of the battery housing during the milling process includes performing a positive pressure test on the battery housing.

12. The battery milling method according to any one of claims 1 to 11, wherein: The welding defect includes at least one of a forming defect and a connection defect.

13. The battery milling method according to claim 12, wherein: The forming defect includes at least one of a burst point defect, a pinhole defect, a pit defect and a shrinkage cavity defect.

14. The battery milling method according to claim 12, wherein: The connection defects include cracks and / or undercuts.

15. A battery milling device comprising: An image acquisition mechanism (30) is configured to acquire an image of a weld of the battery housing; a milling mechanism (10) configured to mill; and A controller is electrically connected to the image acquisition mechanism (30) and the milling mechanism (10), and the controller is configured to acquire the position of the welding defect based on the image of the weld acquired by the image acquisition mechanism (30) and through the image of the weld, and the controller is further configured to control the movement of the milling mechanism (10) according to the position of the welding defect and to mill the welding defect to form a milling groove.

16. The battery milling device according to claim 15, wherein The image acquisition mechanism (30) is configured to acquire at least two images of at least two welds of the battery housing, and the controller is configured to determine whether both of the at least two welds have welding defects based on the at least two images; if both of the at least two welds have welding defects, the positions of the at least two welding defects are acquired based on the at least two images.

17. The battery milling device according to claim 15 or 16, wherein The image acquisition mechanism (30) includes a visual camera (31).

18. The battery milling device according to claim 17, wherein The visual camera (31) is configured to be movably arranged in a plane parallel to the top surface of the battery housing.

19. The battery milling device according to any one of claims 15 to 18, further comprising a clamp (20), the clamp (20) comprising a rotating platform (23) and a clamping mechanism (21) arranged on the rotating platform (23), the clamping mechanism (21) being used to clamp the battery, and the rotating platform (23) being rotatably arranged to drive the clamping mechanism (21) to rotate to change the position of the battery.

20. The battery milling device according to any one of claims 15 to 18, further comprising a positive charging pressure mechanism (40), wherein the positive charging pressure mechanism (40) is configured to perform positive charging pressure detection on the battery housing.

21. A battery production line, comprising the battery milling equipment and the battery repair welding equipment according to any one of claims 15 to 20, wherein the battery repair welding equipment is used to repair the milling groove.

22. The battery production line according to claim 21, wherein: The battery repair welding device includes a wire feeding mechanism configured to provide a length of welding wire according to a length of the milling groove.

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