A defect detection apparatus and method of a wound cell

Abstract

The application relates to the technical field of battery production, and discloses a detection equipment and method for a wound battery cell, wherein the equipment comprises a rack, a battery cell containing basket arranged on the rack, a disassembling mechanism, a conveying mechanism, two groups of positive plate photographing mechanisms, two groups of positive plate cutting mechanisms and a residual material cutting mechanism. The battery cell containing basket is used for containing a battery cell to be detected. The disassembling mechanism is used for separating a positive plate part and a negative plate part of the battery cell to be detected, and transporting the two separated parts in two different directions. The conveying mechanism is used for transporting the positive plate of the battery cell to be detected to the disassembling mechanism. The two groups of positive plate photographing mechanisms are respectively used for collecting images of the front and back surfaces of the separated positive plate and negative plate. The two groups of positive plate cutting mechanisms are respectively used for cutting the positive plate part and the negative plate part. The residual material cutting mechanism is used for cutting the battery cell to be detected. The equipment can automatically realize the detection of defects in the internal part of the sample battery cell, improve the detection efficiency and reduce the missing detection probability.

Description

Technical Field

[0001] This invention relates to the field of battery cell manufacturing technology, and specifically to a defect detection device and method for wound battery cells. Background Technology

[0002] Currently, battery cells are mainly composed of wound cells or stacked cells. Wound cells are formed by stacking and pressing positive electrode sheets, separators, and negative electrode sheets to create a layered structure. During the production process of wound cells, defects such as scratches on the electrodes or separators may occur due to improper equipment parameter settings. These defects can affect battery performance and even pose safety hazards. Therefore, it is necessary to conduct random inspections of the cells, disassembling and testing them to check for scratches and other defects on the positive electrode sheets, negative electrode sheets, and separators. Samples of the defective sections are retained for anomaly analysis to improve the production process and increase yield. Currently, defect inspection of battery cells is done manually, which is inefficient and susceptible to errors due to the experience and focus of the inspectors, potentially leading to missed defects. Therefore, it is necessary to design a defect inspection device for wound cells to improve the efficiency and accuracy of defect detection. Summary of the Invention

[0003] In order to overcome the shortcomings of the prior art, the purpose of this invention is to provide a defect detection device for wound battery cells, which can automatically disassemble the stacked structure of the battery cell and automatically complete the defect detection and sampling of the positive electrode, negative electrode and separator inside the battery cell, thereby improving the efficiency of battery cell sampling and reducing the probability of missed detection.

[0004] To solve the above problems, the technical solution adopted by the present invention is as follows: a defect detection device for wound battery cells, comprising: a frame; a battery cell holding basket disposed on the frame for holding the battery cells to be inspected; a disassembly mechanism disposed on the frame for separating the positive electrode portion and the negative electrode portion of the battery cell to be inspected, and transporting the separated positive electrode portion and the negative electrode portion in two different directions; a conveying mechanism disposed on the frame, between the disassembly mechanism and the battery cell holding basket, for transporting the stacked structure of the battery cell to be inspected to the disassembly mechanism; and two sets of electrode photographing mechanisms. The system comprises two sets of electrode imaging mechanisms, each positioned on the conveyor path of the separated positive and negative electrode portions, mounted on the frame. These mechanisms are used to acquire and scan images of both sides of the separated positive and negative electrode portions. Two sets of electrode cutting mechanisms, also mounted on the frame and positioned after the two sets of electrode imaging mechanisms, are used to cut the separated positive and negative electrode portions. A waste material cutting mechanism, mounted on the frame between the cell holding basket and the conveyor mechanism, is used to cut the stacked structure of the cells to be tested.

[0005] Compared to existing technologies, the advantages of this invention are as follows: The disassembly mechanism automatically separates the battery cell's laminated structure into a positive electrode portion composed of a positive electrode sheet and a positive electrode separator, and a negative electrode portion composed of a negative electrode sheet and a negative electrode separator. These two portions are then transported in two different directions, allowing two sets of electrode scanning mechanisms to scan both sides of the positive and negative electrode portions. This enables the identification of defects in the scanned images using a visual model trained with defect image samples, achieving automatic detection of internal defects within the battery cell. Simultaneously, two sets of electrode cutting mechanisms and waste material cutting mechanisms can cut off defective portions and the tail section of the laminated structure, facilitating subsequent analysis of the defect causes and improvements to the production process. This inspection equipment can automatically disassemble the battery cell and identify and detect internal defects using machine vision, improving defect detection efficiency and avoiding the influence of human factors, thus preventing missed defects.

[0006] The aforementioned defect detection equipment for wound battery cells includes a disassembly mechanism comprising two steering shafts and two sets of pressing mechanisms. The two steering shafts are rotatably mounted on the frame, and a narrow slit is provided between the two steering shafts, allowing the stacked structure of the battery cell to be inspected to pass through. The two sets of pressing mechanisms are respectively located on the left and right sides of the two steering shafts. After passing through the two steering shafts, the stacked structure separates into a positive electrode portion and a negative electrode portion. The separated positive electrode portion and negative electrode portion pass through the two sets of pressing mechanisms, which are used to pull the separated positive electrode portion and negative electrode portion to move in two different directions, left and right. Under the traction force of the two sets of pressing mechanisms, the stacked structure of the battery cell to be inspected is torn apart and separated into a positive electrode portion and a negative electrode portion.

[0007] The aforementioned defect detection equipment for wound battery cells has the same structure for both sets of pressing and conveying mechanisms, each including an active roller and a pressure roller. The active roller is rotatably mounted on the frame and can rotate under the drive of an active motor. The pressure roller is rotatably mounted on a pressure driving mechanism, which is used to drive the pressure roller to approach or move away from the active roller.

[0008] The aforementioned defect detection equipment for wound battery cells includes an electrode imaging mechanism comprising an imaging platform, an upper line scanner, an upper light source assembly, a lower line scanner, and a lower light source assembly. The imaging platform is horizontally mounted on the frame and has a transparent window that allows light to pass through. The upper line scanner and the upper light source assembly are positioned directly above the imaging platform, and the lower line scanner and the lower light source assembly are positioned directly below the imaging platform.

[0009] In the aforementioned defect detection equipment for wound battery cells, both the upper and lower line scanning cameras are slidably mounted on the frame via adjustable slide rails, and the upper and lower line scanning cameras can slide along the adjustable slide rails in the vertical direction.

[0010] The aforementioned defect detection equipment for wound battery cells has the same structure for both sets of electrode cutting mechanisms and scrap cutting mechanisms, each including a cutting platform, a cutting mechanism, and a cutting drive mechanism. The cutting drive mechanism is located on one side of the cutting platform. The stacked structure of the battery cell to be tested, as well as the positive electrode portion or negative electrode portion after the stacked structure is separated, passes through the cutting platform. The cutting mechanism can reciprocate along the surface of the cutting platform under the drive of the cutting drive mechanism in the width direction of the positive electrode portion, the negative electrode portion, or the stacked structure.

[0011] The aforementioned defect detection equipment for wound battery cells includes a cutting mechanism comprising a micrometer platform and a circular cutting blade. The cutting blade is rotatably mounted on the micrometer platform, which is connected to the cutting drive mechanism. The micrometer platform is used to adjust the gap between the cutting blade and the corresponding cutting platform. The cutting platform has a cutting area, and a row of vacuum suction holes is provided on both sides of the cutting area. The cutting platform has a cavity communicating with the vacuum suction holes, and the cavity is connected to a vacuum source.

[0012] The aforementioned defect detection equipment for wound battery cells includes a material turning auxiliary mechanism above the battery cell holding basket. The material turning auxiliary mechanism includes a material turning swing arm, a material turning drive mechanism, and a material turning suction cup. The first end of the material turning swing arm is rotatably mounted on the frame, and the material turning suction cup is mounted on the second end of the material turning swing arm. The material turning swing arm can swing around the first end of the material turning swing arm as the rotation center under the drive of the material turning drive mechanism. The material turning suction cup can adsorb the surface of the battery cell located in the battery cell holding basket.

[0013] A method for detecting defects in the aforementioned wound battery cell includes the following steps:

[0014] S100: The battery cell to be tested is placed on the equipment, and the lead of the battery cell's stacked structure is transported to the disassembly mechanism through the conveying mechanism. The stacked structure is then peeled into the positive electrode portion and the negative electrode portion under the traction of the two sets of pressing and conveying mechanisms of the separation mechanism.

[0015] S200: Two sets of electrode imaging mechanisms scan the front and back sides of the separated positive electrode portion and negative electrode portion respectively to obtain photos of the positive electrode portion and negative electrode portion;

[0016] S300: A visual recognition model trained from defect images of the positive and negative electrode portions identifies whether there are defects in the scanned photos of the positive and negative electrode portions, and records the location and size parameters of the defects when they are detected.

[0017] S400: Calculates the cutting position of the electrode cutting mechanism based on the location and size parameters of the scanned defects, and drives the electrode cutting mechanism to cut the positive electrode or negative electrode when the positive electrode part or negative electrode part moves to the corresponding position. After the cutting is completed, the disassembly mechanism and the conveying mechanism are stopped, and an alarm is issued to remind the operator to take away the cut defect sample segment.

[0018] S500: After the defective sample section is removed, restart the disassembly mechanism and the conveying mechanism, and repeat steps S200 to S400 until the unwinding length of the battery cell reaches the preset value.

[0019] S600: After the unwinding length of the battery cell reaches the preset value, the disassembly mechanism and the conveying mechanism are stopped, and the residual material cutting mechanism is driven to cut the stacked structure of the battery cell to obtain the end section of the stacked structure of the battery cell. After the cutting is completed, an alarm is issued and the trapezoidal operator takes away the end section and stores it together with the defective sample section.

[0020] The above detection method, wherein step S400 includes:

[0021] S410: Obtain the length and position of both ends of the defect area;

[0022] S420: Extend the length positions at both ends of the defect area to a preset length in both directions to obtain the cutting positions at both ends of the defect sample segment.

[0023] S430: Monitor the transmission distance of the two pressing and conveying mechanisms in the disassembly mechanism. When the transmission distance of the corresponding pressing and conveying mechanism is equal to the cutting position, pause the disassembly mechanism and the conveying mechanism, and drive the electrode cutting mechanism to cut the positive electrode part or the negative electrode part once.

[0024] S440: After both ends of the defective sample segment have been cut, the disassembly and conveying mechanisms will stop, and an alarm will be issued to remind the operator to remove the cut-off defective sample segment.

[0025] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0026] Figure 1 This is a front view of the cell defect detection device according to an embodiment of the present invention;

[0027] Figure 2This is a three-dimensional schematic diagram of the main structure of the detection device according to an embodiment of the present invention;

[0028] Figure 3 This is a front view of the main structure of the detection device according to an embodiment of the present invention;

[0029] Figure 4 This is a schematic diagram of the pressing and feeding mechanism according to an embodiment of the present invention;

[0030] Figure 5 This is a side view of the main structure of the detection device according to an embodiment of the present invention;

[0031] Figure 6 This is a three-dimensional structural schematic diagram of the electrode cutting mechanism according to an embodiment of the present invention;

[0032] Figure 7 This is a side view of the electrode cutting mechanism according to an embodiment of the present invention;

[0033] Figure 8 This is a three-dimensional structural diagram of the electrode imaging mechanism according to an embodiment of the present invention.

[0034] Explanation of icon numbers:

[0035] 100 Frame, 110 Three-color alarm light, 120 Display screen, 130 Computer, 200 Battery cell holding basket, 210 Tilting swing arm, 220 Tilting suction cup, 230 Tilting drive mechanism, 300 Disassembly mechanism, 310 Steering shaft, 320 Pressing and feeding mechanism, 321 Drive roller, 322 Pressing roller, 323 Pressing drive mechanism, 324 Drive motor, 400 Conveying mechanism, 500 Electrode photographing mechanism, 510 Upper line scanning camera, 520 Upper light source assembly, 530 Lower light source assembly, 540 Lower line scanning camera, 550 Photographing platform, 560 Adjustable slide rail, 570 Light blocking door, 600 Electrode cutting mechanism, 610 Cutting platform, 611 Vacuum suction hole, 612 Guide plate, 620 Cutting mechanism, 621 Dividing table, 622 Cutting knife, 630 Cutting knife drive mechanism, 700 Excess material cutting mechanism, 800 Scrap bin. Detailed Implementation

[0036] The embodiments of the present invention are described in detail below, with reference to... Figures 1 to 5This invention provides a defect detection device for wound battery cells, including a frame 100 and a battery cell holding basket 200, a disassembly mechanism 300, a conveying mechanism 400, two sets of electrode photographing mechanisms 500, two sets of electrode cutting mechanisms 600, and a waste material cutting mechanism 700 disposed on the frame 100. The battery cell holding basket 200 holds the battery cells to be inspected. The disassembly mechanism 300 divides the electrode sheets of the battery cell into two parts, one part including a positive electrode sheet and a positive electrode sheet separator, and the other part including a negative electrode sheet and a negative electrode sheet separator, and transports the positive electrode sheet part and the negative electrode sheet part in two different directions. The conveying mechanism 400 is disposed between the battery cell holding basket 200 and the disassembly mechanism 300, and is used to transport the stacked structure of the battery cell before separation to the disassembly mechanism 300. The two sets of electrode photographing mechanisms 500 are respectively disposed on the conveyor paths of the separated positive electrode sheet part and the negative electrode sheet part, and are used to collect images of the front and back sides of the separated parts. Two sets of electrode cutting mechanisms 600 are respectively set after the two sets of electrode photographing mechanisms 500, and are used to cut the positive electrode portion and the negative electrode portion. The waste material cutting mechanism 700 is set between the cell holding basket 200 and the conveying mechanism 400, and is used to cut the stacked structure before the cell is separated.

[0037] The defect detection equipment for wound battery cells in this embodiment of the invention involves manually disassembling a section of the stacked structure of the wound battery cell and placing it on the disassembly mechanism 300 and the conveying mechanism 400. The disassembly mechanism 300 automatically disassembles the stacked structure of the battery cell into two parts: a positive electrode portion and a negative electrode portion. This allows the two sets of electrode imaging mechanisms 500 to sample images of the internal structure of the laminated structure. Based on a trained visual model, defects on the positive electrode, negative electrode, and separator can be automatically identified and detected, improving the defect detection efficiency of the battery cell and avoiding false positives and false negatives due to human factors. Simultaneously, after a defect is detected, the electrode cutting mechanism 600 automatically cuts off the defective section. After the inspection is completed, the remaining material cutting mechanism 700 cuts off the end section of the stacked structure of the battery cell, facilitating the storage of the defective section and the end section together. This allows analysts to analyze and trace the causes of defects later.

[0038] Reference Figure 2 , Figure 3 and Figure 4In this embodiment, the disassembly mechanism 300 includes two steering shafts 310 and two sets of pressing mechanisms 320. The two steering shafts 310 are rotatably mounted on the frame 100, and a narrow slit is provided between the two steering shafts 310, allowing the stacked structure of the battery cell to be tested to pass through. The two sets of pressing mechanisms 320 are respectively located on the left and right sides of the two steering shafts 310. After passing through the two steering shafts 310, the stacked structure separates into a positive electrode portion and a negative electrode portion. The positive electrode portion and the negative electrode portion are deflected by 180 degrees by the two steering shafts 310, changing from vertical to horizontal, and respectively pass through the two sets of pressing mechanisms 320 located on the left and right sides of the two steering shafts 310. Two sets of pressing mechanisms 320 are used to press the positive electrode portion and the negative electrode portion respectively, and provide traction forces in two different directions, left and right, to the positive electrode portion and the negative electrode portion respectively, thereby tearing the laminated structure back into the positive electrode portion and the negative electrode portion, so that the two sets of electrode imaging mechanisms 500 can scan and photograph the internal defects of the electrode. (Refer to...) Figure 3 In this embodiment, one of the two steering shafts 310 is slidably mounted on the frame via a slide rail. The distance between this steering shaft 310 and the other steering shaft 310 can be adjusted via the slide rail to accommodate the stacked structure of battery cells of different thicknesses. In this embodiment, the pressing mechanism 320 and the conveying mechanism 400 have the same structure, both including a drive roller 321 and a pressing roller 322. The drive roller 321 is rotatably mounted on the frame 100 and can rotate under the drive of the drive motor 324. The pressing roller 322 is rotatably mounted on the pressing drive mechanism 323, which is used to drive the pressing roller 322 to approach or move away from the drive roller 321. In this embodiment, the pressing drive mechanism 323 includes a movable support, a guide rod, and a pressing cylinder. The pressing roller 322 is rotatably mounted on the movable support, which is slidably connected to the guide rod. The guide rod is fixedly mounted on the frame 100 via a support structure. The pressing cylinder is mounted on the frame 100, and the piston rod of the pressing cylinder is connected to the movable support. After the piston rod of the pressing cylinder extends, it drives the pressing roller 322 to press on the active roller 321, pressing the positive and negative electrode portions or the stacked structure before separation onto the active roller 321, so that there is sufficient static friction between the electrode and the active roller 321, so that when the active motor 324 drives the active roller 321 to rotate, it can apply sufficient traction force to the electrode.

[0039] Reference Figure 2 , Figure 3 and Figure 7In this embodiment, the electrode imaging mechanism 500 uses a 4K resolution line scan camera to scan images of the front and back sides of the separated positive and negative electrode portions. The electrode imaging mechanism 500 includes an imaging platform 350, an upper line scan camera 510, an upper light source assembly 520, a lower line scan camera 540, and a lower light source assembly 530. The upper line scan camera 510 and the upper light source assembly 520 are disposed above the imaging platform 350, and the lower line scan camera 540 and the lower light source assembly 530 are disposed below the imaging platform 350. The imaging platform 350 is provided with a transparent window that allows light to pass through, so that the light emitted by the lower light source assembly 530 can pass through the transparent window and illuminate the lower surface of the positive and negative electrode portions, and be reflected into the lower line scan camera 540 for imaging. In this embodiment, both the upper line scanning camera 510 and the lower line scanning camera 540 are slidably connected to the frame 100 via adjusting slide rails 560 vertically mounted on the frame 100. This allows adjustment of the height of the line scanning camera from the imaging platform 350, thereby adjusting the field of view of the line scanning camera. In this embodiment, both the upper light source assembly 520 and the lower light source assembly 530 consist of two strip light sources, which are mounted on the frame 100 via a support structure. Both the upper light source assembly 520 and the lower light source assembly 530 are also covered by light-blocking covers with openable and closable light-blocking doors 570 to prevent ambient light from affecting the detection.

[0040] Reference Figure 2 , Figure 5 and Figure 6In this embodiment, the electrode cutting mechanism 600 and the waste material cutting mechanism 700 have basically the same structure, both including a cutting platform 610, a cutting mechanism 620, and a cutting drive mechanism 630. The cutting drive mechanism 630 is disposed on one side of the cutting platform 610, through which the stacked structure of the battery cell or the separated positive and negative electrode portions pass. Driven by the cutting drive mechanism 630, the cutting mechanism 620 can reciprocate along the surface of the cutting platform 610 in the width direction of the positive electrode portion, negative electrode portion, or stacked structure, thereby cutting the positive and negative electrode portions or stacked structure. In this embodiment, the cutting mechanism 620 includes a micrometer 621 and a circular cutting blade 622 made of tungsten steel. The cutting blade 622 is rotatably disposed on the micrometer 621, which is used to adjust the gap between the cutting blade 622 and the corresponding cutting platform 610. The cutting blade drive mechanism 630 uses a rodless cylinder, and the micrometer stage 621 is mounted on the slider of the rodless cylinder. The cutting platform 610 has a cutting area, the hardness of which should be higher than other areas to prevent scratches from the cutting blade 622 and extend the service life of the cutting blade platform 622. A row of vacuum suction holes 611 is provided on both sides of the cutting area. The cutting platform 610 has a cavity communicating with the vacuum suction holes 611, which is connected to a vacuum source such as a vacuum generator. This allows the positive and negative electrode portions or stacked structures on the cutting platform 610 to be adsorbed during cutting, ensuring stability during the cutting process. (Refer to...) Figure 1 In this embodiment, waste bins 800 are provided on both sides of the frame 100 for recycling the defect-free positive and negative electrode portions. A guide plate 612 is provided at the end of the cutting platform 610 of the electrode cutting mechanism 600 facing away from the dismantling mechanism 300. The guide plate 612 is an arc-shaped plate that smoothly guides the positive or negative electrode portions passing through the electrode cutting mechanism 600 into the waste bins 800 below.

[0041] Reference Figure 1In this embodiment, the rack 100 is also equipped with a three-color alarm light 110 to alert the operator, reminding them to remove the cut-off defective sample segment when a defect is detected, and to remind the operator after disassembly and inspection are completed. The rack 100 is equipped with a display screen 120 to display images of the positive and negative electrode portions scanned in real time by four line scanning cameras. The rack 100 is also equipped with a computer 130 to store the images scanned by the line scanning cameras, detect defects in the stored images using a defect detection visual model, and control the disassembly mechanism 300, conveying mechanism 400, electrode cutting mechanism 600, and waste material cutting mechanism 700 based on the detection results. The computer 130 is also used to connect peripheral devices such as a keyboard, mouse, and barcode scanner to input equipment parameters, scan QR codes on the battery cells to obtain production information, and upload inspection information to the MES system. The rack 100 is also equipped with various control buttons for manual control of the equipment.

[0042] Reference Figure 2 and Figure 3 Since wound battery cells are often flattened before being placed into the battery, in some embodiments, to prevent the flat, round battery cells from experiencing periodic fluctuations in electrode tension due to difficulty in rotation during unwinding, which could affect the positioning accuracy of the conveying mechanism 400 and the disassembly mechanism 300, a turning auxiliary mechanism is provided inside the battery cell holding basket 200. The turning auxiliary mechanism includes a turning swing arm 210, a turning drive mechanism 230, and a turning suction cup 220. The first end of the turning swing arm 210 is rotatably mounted on the frame 100, and the turning suction cup 220 is located at the second end of the turning swing arm 210. The turning swing arm 210 can swing around its first end as the rotation center under the drive of the turning drive mechanism 230. When the turning suction cup 220 contacts the surface of the battery cell, it can adhere to the surface of the battery cell in the battery cell holding basket 200, allowing the battery cell to swing together with the turning swing arm 210, thereby assisting the flat, round battery cell in rotating and unwinding within the battery cell holding basket 200. In this embodiment, the material turning drive mechanism 230 is a motor, and the output shaft of the motor is connected to the rotating shaft of the material turning swing arm 210.

[0043] The specific inspection process of the cell defect detection equipment according to this invention includes the following steps:

[0044] S100: The battery cell to be tested is placed on the equipment, and the lead of the battery cell's stacked structure is transported to the disassembly mechanism 300 through the conveying mechanism 400. The stacked structure is then peeled into the positive electrode portion and the negative electrode portion under the traction of the two sets of pressing and conveying mechanisms 320 of the separation mechanism.

[0045] S200: Two sets of electrode imaging mechanisms 500 scan the front and back sides of the separated positive electrode portion and negative electrode portion respectively to obtain photographs of the positive electrode portion and negative electrode portion;

[0046] S300: A visual recognition model trained from defect images of the positive and negative electrode portions identifies whether there are defects in the scanned photos of the positive and negative electrode portions, and records the location and size parameters of the defects when they are detected.

[0047] S400: Calculates the cutting position of the electrode cutting mechanism 600 based on the location and size parameters of the scanned defects, and drives the electrode cutting mechanism 600 to cut the positive electrode part or the negative electrode part when the positive electrode part or the negative electrode part moves to the corresponding position. After the cutting is completed, the disassembly mechanism 300 and the conveying mechanism 400 are stopped, and an alarm is issued to remind the operator to take away the cut defect sample segment.

[0048] S500: After the defective sample segment is removed, restart the disassembly mechanism 300 and the conveying mechanism 400, and repeat steps S200 to S400 until the unwinding length of the battery cell reaches the preset value.

[0049] S600: After the unwinding length of the battery cell reaches the preset value, the disassembly mechanism 300 and the conveying mechanism 400 are stopped, and the residual material cutting mechanism is driven to cut the stacked structure of the battery cell to obtain the end section of the stacked structure of the battery cell. After the cutting is completed, an alarm is issued and the trapezoidal operator takes away the end section and stores it together with the defective sample section.

[0050] In some embodiments, before setting up the battery cell, the QR code on the battery cell can be scanned with a barcode scanner to obtain the production information of the sampled battery cell. After the inspection is completed, the defect detection results are uploaded to the corresponding column of the battery cell in the MES system according to the production information of the battery cell, so as to facilitate the traceability of the battery cell information.

[0051] In this embodiment, step S400 specifically includes:

[0052] S410: Obtain the length and position of both ends of the defect area;

[0053] S420: Extend the length positions at both ends of the defect area to a preset length in both directions to obtain the cutting positions at both ends of the defect sample segment.

[0054] S430: Monitor the transmission distance of the two pressing and conveying mechanisms 320 in the disassembly mechanism 300. When the transmission distance of the corresponding pressing and conveying mechanism 320 is equal to the cutting position, pause the disassembly mechanism 300 and the conveying mechanism 400, and drive the electrode cutting mechanism 600 to cut the positive electrode part or the negative electrode part once.

[0055] S440: After both ends of the defective sample segment have been cut, stop the disassembly mechanism 300 and the conveying mechanism 400, and issue an alarm to remind the operator to remove the cut-off defective sample segment.

[0056] Taking the positive electrode section as an example, when the electrode imaging mechanism 500 on the positive electrode section detects a defect on the surface of the positive electrode or separator, it identifies the length position of both ends of the defect through a visual model, and extends outward by a preset length, such as 100mm, based on the length position of both ends of the defect to calculate the cutting position. When the transport length of the pressing and conveying mechanism 320 of the disassembly mechanism 300 reaches the cutting position, the disassembly mechanism 300 and the conveying mechanism 400 are paused, and the electrode cutting mechanism 600 on the positive electrode section is activated to cut the positive electrode section. After cutting is completed at both cutting positions, the disassembly mechanism 300 and the conveying mechanism 400 are stopped, and the three-color alarm light 110 is activated to sound an alarm. It can be understood that the visual model for defect detection can be obtained by training a neural network model, such as a convolutional neural network, using pre-collected defect image samples as training samples. The length and position of the positive and negative electrode portions scanned by the two sets of electrode photographing mechanisms 500 should be based on the unwinding length corresponding to the cutter 622 on the same side of the electrode cutting mechanism 600, so that the cutting position can be directly calculated from the position of the two ends of the defect in the photograph.

[0057] It is understandable that if there are defects with overlapping length positions on both sides of the positive electrode portion, in order to ensure the integrity of the defects on the cut sample segment, the cutting position should be calculated by using the maximum and minimum values ​​of the length positions of the two ends of all defects on both sides of the positive electrode portion as the reference for outward expansion.

[0058] It should be noted that in the description of this invention, any descriptions of orientation, such as up, down, front, back, left, right, etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings. They are only for the purpose of facilitating the description of this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed or operated in a specific orientation, and should not be construed as a limitation of this invention.

[0059] In the description of this invention, "several" means one or more, "more than" means two or more, "greater than," "less than," "exceeding," etc. are understood to exclude the stated number, while "above," "below," "within," etc. are understood to include the stated number. If "first" or "second" is mentioned, it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0060] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0061] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A defect detection device for wound battery cells, characterized in that, include: Rack (100); A battery cell holding basket (200) is set on the frame (100) and is used to hold the battery cells to be tested; A disassembly mechanism (300) is provided on the frame (100) for separating the positive electrode portion and the negative electrode portion of the battery cell to be tested, and transporting the separated positive electrode portion and the negative electrode portion in two different directions; A conveying mechanism (400) is disposed on the frame (100) and between the disassembly mechanism (300) and the cell holding basket (200), for transporting the electrode of the cell to be tested to the disassembly mechanism (300); Two sets of electrode imaging mechanisms (500) are set on the frame (100). The two sets of electrode imaging mechanisms (500) are respectively set on the conveyor paths of the separated positive electrode portion and negative electrode portion, and are used to collect and scan images of the front and back sides of the separated positive electrode portion and negative electrode portion. Two sets of electrode cutting mechanisms (600) are mounted on the frame (100). The two sets of electrode cutting mechanisms (600) are respectively mounted after the two sets of electrode photographing mechanisms (500) and are used to cut the separated positive electrode portion and negative electrode portion. The waste material cutting mechanism (700) is set on the frame (100) and between the battery cell holding basket (200) and the conveying mechanism (400), and is used to cut the stacked structure of the battery cell to be tested; The disassembly mechanism (300) includes two steering shafts (310) and two sets of pressing mechanisms (320). The two steering shafts (310) are rotatably mounted on the frame (100). A narrow slit is provided between the two steering shafts (310) so that the stacked structure of the battery cell to be tested can pass through. The two sets of pressing mechanisms (320) are respectively located on the left and right sides of the two steering shafts (310). After the stacked structure passes through the two steering shafts (310), it is separated into a positive electrode portion and a negative electrode portion. The separated positive electrode portion and negative electrode portion pass through the two sets of pressing mechanisms (320) respectively. The pressing mechanism (320) is used to pull the separated positive electrode portion and negative electrode portion to move in two different directions to the left and right. The stacked structure of the battery cell to be tested is torn apart and separated into a positive electrode portion and a negative electrode portion under the traction force of the two sets of pressing mechanisms (320). The two sets of electrode cutting mechanisms (600) and the scrap cutting mechanism (700) have the same structure, each including a cutting platform (610), a cutting mechanism (620) and a cutting drive mechanism (630); The cutting mechanism (620) includes a micrometer stage (621) and a circular cutter (622). The cutter (622) is rotatably mounted on the micrometer stage (621). The micrometer stage (621) is connected to the cutter driving mechanism. The micrometer stage (621) is used to adjust the gap between the cutter (622) and the corresponding cutting platform (610). The cutting platform (610) is provided with a cutting area. A row of vacuum suction holes (611) is provided on both sides of the cutting area. The cutting platform (610) is provided with a cavity communicating with the vacuum suction holes (611). The cavity is connected to a vacuum source. If there are defects with overlapping length positions on both sides of the positive electrode portion, in order to ensure the integrity of the defects on the cut sample segment, when calculating the cutting position, the maximum and minimum values ​​of the length positions of the two ends of all defects on both sides of the positive electrode portion should be used as the reference for outward expansion to calculate the cutting position. Above the battery cell holding basket (200) is a flipping auxiliary mechanism, which includes a flipping swing arm (210), a flipping drive mechanism (230), and a flipping suction cup (220). The first end of the flipping swing arm (210) is rotatably mounted on the frame (100), and the flipping suction cup (220) is mounted on the second end of the flipping swing arm (210). The flipping swing arm (210) can swing around the first end of the flipping swing arm (210) as the rotation center under the drive of the flipping drive mechanism (230), and the flipping suction cup (220) can adsorb the surface of the battery cell located in the battery cell holding basket (200).

2. The defect detection equipment for wound battery cells according to claim 1, characterized in that, The two sets of pressing mechanisms (320) and conveying mechanisms (400) have the same structure, each including a drive roller (321) and a pressing roller (322). The drive roller (321) is rotatably mounted on the frame (100) and can rotate under the drive of the drive motor (324). The pressing roller (322) is rotatably mounted on the pressing drive mechanism (323) and the pressing drive mechanism (323) is used to drive the pressing roller (322) to approach or move away from the drive roller (321).

3. The defect detection equipment for wound battery cells according to claim 1, characterized in that, The electrode imaging mechanism (500) includes an imaging platform (350), an upper linear scanning camera (510), an upper light source assembly (520), a lower linear scanning camera (540), and a lower light source assembly (530). The imaging platform (350) is horizontally mounted on the frame (100). The imaging platform (350) has a transparent window that allows light to pass through. The upper linear scanning camera (510) and the upper light source assembly (520) are positioned directly above the imaging platform (350), and the lower linear scanning camera (540) and the lower light source assembly (530) are positioned directly below the imaging platform (350).

4. The defect detection equipment for wound battery cells according to claim 3, characterized in that, The upper line scanning camera (510) and the lower line scanning camera (540) are both slidably mounted on the frame (100) via an adjusting slide rail (560). The upper line scanning camera (510) and the lower line scanning camera (540) can slide along the adjusting slide rail (560) in the vertical direction.

5. The defect detection equipment for wound battery cells according to claim 1, characterized in that, The cutting drive mechanism (630) is disposed on one side of the cutting platform (610). The stacked structure of the battery cell to be tested, as well as the positive electrode portion or negative electrode portion after the stacked structure is separated, passes through the cutting platform (610). The cutting mechanism (620) can reciprocate along the surface of the cutting platform (610) in the width direction of the positive electrode portion, the negative electrode portion, or the stacked structure under the drive of the cutting drive mechanism (630).

6. A method for detecting defects in a wound battery cell according to any one of claims 1 to 5, characterized in that, Includes the following steps: S100: The battery cell to be tested is placed on the equipment, and the lead of the battery cell's stacked structure is transported to the disassembly mechanism (300) through the conveying mechanism (400), and the stacked structure is stripped into the positive electrode part and the negative electrode part under the traction of the two sets of pressing and conveying mechanisms (320) of the separation mechanism. S200: Two sets of electrode imaging mechanisms (500) scan the front and back sides of the separated positive electrode portion and negative electrode portion respectively to obtain photographs of the positive electrode portion and negative electrode portion; S300: A visual model trained from defect images of the positive electrode, negative electrode and separator identifies whether there are defects in the scanned images of the positive electrode and negative electrode, and records the location and size parameters of the defect when a defect is identified. S400: Calculate the cutting position of the electrode cutting mechanism (600) based on the location and size parameters of the scanned defects, and drive the electrode cutting mechanism (600) to cut the positive electrode part or the negative electrode part when the positive electrode part or the negative electrode part moves to the corresponding position. After the cutting is completed, stop the disassembly mechanism (300) and the conveying mechanism (400) and issue an alarm to remind the operator to take away the cut defect sample segment. S500: After the defective sample segment is removed, restart the disassembly mechanism (300) and the conveying mechanism (400), and repeat steps S200 to S400 until the unwinding length of the battery cell reaches the preset value. S600: After the unwinding length of the battery cell reaches the preset value, the disassembly mechanism (300) and the conveying mechanism (400) are stopped, and the residual material cutting mechanism is driven to cut the stacked structure of the battery cell to obtain the end section of the stacked structure of the battery cell. After the cutting is completed, an alarm is issued and the trapezoidal operator takes away the end section and stores the end section together with the defective sample section.

7. The detection method according to claim 6, characterized in that, Step S400 includes: S410: Obtain the length and position of both ends of the defect area; S420: Extend the length positions at both ends of the defect area by a preset length in both directions to obtain the cutting positions at both ends of the defect sample segment. S430: Monitor the transmission distance of the two pressing and conveying mechanisms (320) in the disassembly mechanism (300). When the transmission distance of the corresponding pressing and conveying mechanism (320) is equal to the cutting position, pause the disassembly mechanism (300) and the conveying mechanism (400), and drive the electrode cutting mechanism (600) to cut the positive electrode part or the negative electrode part once. S440: After both ends of the defective sample segment have been cut, stop the disassembly mechanism (300) and the conveying mechanism (400) and issue an alarm to remind the operator to take away the cut-off defective sample segment.

Images