Defect detection equipment and method for winding battery cell

Abstract

The invention relates to the technical field of battery production, and discloses a detection device and method for a wound battery cell, and the device comprises a rack, and a battery cell containing basket, a disassembling mechanism, a conveying mechanism, two groups of pole piece photographing mechanisms, two groups of pole piece cutting mechanisms and an excess material cutting mechanism which are arranged on the rack. The battery cell containing basket is used for containing a to-be-detected battery cell. And the disassembling mechanism is used for separating the positive plate part and the negative plate part of the to-be-detected battery cell, and transporting the two separated parts in two different directions. The conveying mechanism is used for conveying a pole piece of a to-be-detected battery cell to the disassembling mechanism. The two sets of pole piece photographing mechanisms are used for collecting images of the front faces and the back faces of the scanned and separated positive pole pieces and negative pole pieces correspondingly, the two sets of pole piece cutting mechanisms are used for cutting the positive pole pieces and the negative pole pieces correspondingly, and the excess material cutting mechanism is used for cutting the to-be-detected battery cells. The equipment can automatically detect the internal defects of the casual inspection battery cell, so that the detection efficiency is improved, and the probability of missed detection is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of battery cell production and manufacturing, and in particular to a defect detection device and method for a wound battery cell. Background Art

[0002] At present, the battery cells are mainly wound cells or laminated cells, in which the wound cells are wound by stacking and pressing the positive electrode sheet, the diaphragm and the negative electrode sheet to form a laminated structure. In the production process of wound cells, due to inappropriate equipment parameter settings and other reasons, scratches and other defects may appear on the electrode sheet or diaphragm of the produced cells. These defects will affect the performance of the battery and even bring safety hazards. Therefore, it is necessary to conduct random inspections of the cells, disassemble and inspect the cells, and detect whether there are scratches and other defects on the positive electrode sheet, negative electrode sheet and diaphragm of the cells, and keep samples of the defective sections for abnormal analysis, improve the production process and increase the yield. At present, the disassembly defect detection of the cells is done manually, the detection efficiency is low, and the identification of defects is affected by the experience and concentration of the inspectors, and there may be missed detections. Therefore, it is necessary to design a defect detection device for wound cells to improve the efficiency and accuracy of defect detection of cells. Summary of the invention

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

[0004] In order 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, which is arranged on the frame and is used to hold the battery cells to be detected; a disassembly mechanism, which is arranged on the frame and is used to separate the positive electrode sheet part and the negative electrode sheet part of the battery cells to be detected, and transport the separated positive electrode sheet part and the negative electrode sheet part to two different directions; a conveying mechanism, which is arranged on the frame and between the disassembly mechanism and the battery cell holding basket, and is used to transport the stacked structure of the battery cells to be detected to the disassembly mechanism; two sets of electrode sheet photography mechanisms , arranged on the frame, the two sets of electrode sheet photographing mechanisms are respectively arranged on the belt paths of the separated positive electrode sheet part and the negative electrode sheet part, and are used to collect and scan the images of the front and back sides of the separated positive electrode sheet part and the negative electrode sheet part; two sets of electrode sheet cutting mechanisms are arranged on the frame, the two sets of electrode sheet cutting mechanisms are respectively arranged behind the two sets of electrode sheet photographing mechanisms, and are used to cut the separated positive electrode sheet part and the negative electrode sheet part; the residual material cutting mechanism is arranged on the frame, and is arranged between the battery cell holding basket and the conveying mechanism, and is used to cut the stacked structure of the battery cell to be inspected.

[0005] Compared with the prior art, the beneficial effect of the present invention is that the stacked structure of the battery cell is automatically split into a positive electrode portion composed of a positive electrode sheet and a positive electrode sheet separator, and a negative electrode portion composed of a negative electrode sheet and a negative electrode sheet separator through a disassembly mechanism, and the two portions are transported to two different directions respectively, so that the two sets of electrode photographing mechanisms can take photographs and scan the positive and negative electrode portions and the front and back sides of the positive and negative electrode portions, so that the defects on the pictures obtained by photographing and scanning can be identified through a visual model trained with defective picture samples, thereby realizing automatic detection of internal defects of the battery cell. At the same time, the two sets of electrode cutting mechanisms and the residual material cutting mechanisms can cut off the defective parts and the tail section of the stacked structure, so as to facilitate the subsequent tracing and analysis of the causes of the defects and improve the production process. The detection equipment can automatically disassemble the battery cell and identify and detect internal defects through machine vision, which can improve the efficiency of defect detection, avoid detection being affected by human factors, and avoid missed defects.

[0006] The above-mentioned defect detection equipment for wound battery cells, the disassembly mechanism includes two steering shafts and two sets of pressing mechanisms, the two steering shafts are rotatably arranged on the frame, a slit is arranged between the two steering shafts for the laminated structure of the battery cell to be detected to pass through, the two sets of pressing mechanisms are respectively arranged on the left and right sides of the two steering shafts, the laminated structure is separated into a positive electrode sheet part and a negative electrode sheet part after passing through the two steering shafts, the separated positive electrode sheet part and negative electrode sheet part respectively pass through the two sets of pressing mechanisms, the pressing mechanisms are used to pull the separated positive electrode sheet part and negative electrode sheet part to move in two different directions to the left and right, the laminated structure of the battery cell to be detected is torn apart and separated into a positive electrode sheet part and a negative electrode sheet part under the traction force of the two sets of pressing mechanisms.

[0007] In the above-mentioned defect detection equipment for wound battery cells, the two groups of the pressing mechanism and the conveying mechanism have the same structure, both of which include an active roller and a pressure roller. The active roller is rotatably arranged on the frame, and the active roller can be rotated under the drive of the active motor. The pressure roller is rotatably arranged on the pressure driving mechanism, and the pressure driving mechanism is used to drive the pressure roller to approach or move away from the active roller.

[0008] The above-mentioned defect detection equipment for wound battery cells, the pole piece photographing mechanism includes a photographing platform, an upper line scanning camera, an upper light source assembly, a lower line scanning camera and a lower light source assembly, the photographing platform is horizontally arranged on the frame, and a transparent window for light to pass through is arranged on the photographing platform, the upper line scanning camera and the upper light source assembly are arranged directly above the photographing platform, and the lower line scanning camera and the lower light source assembly are arranged directly below the photographing platform.

[0009] In the above-mentioned defect detection equipment for wound battery cells, the upper line scanning camera and the lower line scanning camera are both slidably arranged on the frame by adjusting the slide rails, and the upper line scanning camera and the lower line scanning camera can slide in the vertical direction along the adjusting slide rails.

[0010] In the above-mentioned defect detection equipment for wound battery cells, the two groups of the electrode sheet cutting mechanism and the residual material cutting mechanism have the same structure, both of which include a cutting platform, a cutting mechanism and a cutting mechanism. The cutting mechanism is arranged on one side of the cutting platform. The stacking structure of the battery cell to be inspected, and the positive electrode sheet part or the negative electrode sheet part after the separation of the stacking structure pass through the cutting platform. The cutting mechanism can reciprocate in the width direction of the positive electrode sheet part, the negative electrode sheet part or the stacking structure along the surface of the cutting platform under the drive of the cutting mechanism.

[0011] The above-mentioned defect detection equipment for wound battery cells, the cutter mechanism includes a micrometer table and a circular cutter, the cutter is rotatably set on the micrometer table, the micrometer table is connected to the cutting drive mechanism, the micrometer table is used to adjust the gap between the cutter and the corresponding cutting platform, a cutting area is provided on the cutting platform, a row of vacuum suction holes are provided on both sides of the cutting area, a cavity connected to the vacuum suction hole is provided inside the cutting platform, and the cavity is connected to the vacuum source.

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

[0013] A detection method of the above-mentioned wound battery cell defect detection device comprises the following steps:

[0014] S100: placing the battery cell to be tested on the equipment, so that the lead of the stacked structure of the battery cell is transported to the disassembling mechanism through the conveying mechanism, and the stacked structure is stripped into a positive electrode sheet part and a negative electrode sheet part under the traction of two sets of pressing mechanisms of the separation mechanism;

[0015] S200: two sets of electrode sheet photographing mechanisms respectively scan the front and back sides of the separated positive electrode sheet part and the negative electrode sheet part to obtain photos of the positive electrode sheet part and the negative electrode sheet part;

[0016] S300: identifying whether there are defects in the scanned photos of the positive electrode sheet and the negative electrode sheet through a visual recognition model trained by defect images of the positive electrode sheet and the negative electrode sheet, and recording the location and size parameters of the defects when defects are identified;

[0017] S400: calculating the cutting position of the electrode sheet cutting mechanism according to the position and size parameters of the scanned defect, and driving the electrode sheet cutting mechanism to cut the positive electrode sheet part or the negative electrode sheet part when the positive electrode sheet part or the negative electrode sheet part moves to the corresponding position, stopping the disassembly mechanism and the conveying mechanism after the cutting is completed, and issuing an alarm to remind the operator to take away the cut defective sample segment;

[0018] S500: After the defective sample segment is taken away, the disassembly mechanism and the conveying mechanism are restarted, and steps S200 to S400 are repeated until the unwinding length of the battery cell reaches a preset value;

[0019] S600: After the unwinding length of the battery cell reaches a preset value, the disassembling mechanism and the conveying mechanism are stopped, and the residual material cutting mechanism is driven to cut the stacking structure of the battery cell to obtain the end section of the stacking 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.

[0020] In the above detection method, step S400 includes:

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

[0022] S420: Extending the length positions of the two ends of the defective area by a preset length on both sides in the length direction to obtain the cutting positions of the two ends of the defective sample segment;

[0023] S430: monitoring the transmission distances of the two pressing and feeding mechanisms in the disassembling mechanism, and when the transmission distance of the corresponding pressing and feeding mechanism is equal to the cutting position, pausing the disassembling mechanism and the conveying mechanism, and driving the electrode sheet cutting mechanism to cut the positive electrode sheet part or the negative electrode sheet part once;

[0024] S440: After the cutting positions at both ends of the defective sample segment are cut, the disassembling mechanism and the conveying mechanism are stopped, and an alarm is issued to remind the operator to take away the cut defective sample segment.

[0025] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

[0029] Figure 4 It is a structural schematic diagram of a pressure-feeding mechanism according to an embodiment of the present invention;

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

[0031] Figure 6 It is a schematic diagram of the three-dimensional structure of the pole piece cutting mechanism according to an embodiment of the present invention;

[0032] Figure 7 A side view of a pole piece cutting mechanism according to an embodiment of the present invention;

[0033] Figure 8 It is a schematic diagram of the three-dimensional structure of the pole piece photographing mechanism according to an embodiment of the present invention.

[0034] Description of Figure Numbers:

[0035] 100 rack, 110 three-color alarm light, 120 display screen, 130 computer, 200 battery cell holding basket, 210 flipping swing arm, 220 flipping suction cup, 230 flipping drive mechanism, 300 disassembly mechanism, 310 steering shaft, 320 pressing mechanism, 321 active roller, 322 pressing roller, 323 pressing drive mechanism, 324 active motor, 400 transmission mechanism, 500 pole piece photographing mechanism, 510 upper online scanning camera, 520 upper light source assembly, 530 lower light source assembly, 540 lower online scanning camera, 550 photographing platform, 560 adjusting slide rail, 570 light blocking door, 600 pole piece cutting mechanism, 610 cutting platform, 611 vacuum suction hole, 612 guide plate, 620 cutter mechanism, 621 thousandth table, 622 cutter, 630 cutter drive mechanism, 700 excess material cutting mechanism, 800 waste box. DETAILED DESCRIPTION

[0036] The embodiments of the present invention are described in detail below. Figures 1 to 5The embodiment of the present invention provides a defect detection device for wound battery cells, including a frame 100 and a battery cell holding basket 200, a disassembling mechanism 300, a conveying mechanism 400, two sets of electrode piece photographing mechanisms 500, two sets of electrode piece cutting mechanisms 600 and a residual material cutting mechanism 700 arranged on the frame 100. The battery cell holding basket 200 is used to hold the battery cells to be inspected, and the disassembling mechanism 300 is used to divide the electrode pieces of the battery cells into two parts, one of which includes a positive electrode piece and a positive electrode piece separator, and the other includes a negative electrode piece and a negative electrode piece separator, and transport the positive electrode piece part and the negative electrode piece part to two different directions respectively. The conveying mechanism 400 is arranged between the battery cell holding basket 200 and the disassembling mechanism 300, and is used to transport the stacked structure of the battery cell before separation to the disassembling mechanism 300. The two sets of electrode piece photographing mechanisms 500 are respectively arranged on the belt path of the positive electrode piece part and the negative electrode piece part after separation, and are used to collect images of the front and back sides of the two separated parts. The two sets of electrode sheet cutting mechanisms 600 are respectively arranged behind the two sets of electrode sheet photographing mechanisms 500, and are used to cut the positive electrode sheet part and the negative electrode sheet part. The residual material cutting mechanism 700 is arranged between the battery cell holding basket 200 and the conveying mechanism 400, and is used to cut the laminated structure before the battery cell is separated.

[0037] The defect detection equipment for wound battery cells of the embodiment of the present invention manually disassembles a section of the laminated structure of the wound battery cell and then sets it on the disassembly mechanism 300 and the conveying mechanism 400. The disassembly mechanism 300 can automatically disassemble the laminated structure of the battery cell into two parts, the positive electrode sheet part and the negative electrode sheet part, so that the two sets of electrode sheet photography mechanisms 500 can sample the internal conditions of the laminated structure after pressing, so that the defects on the positive electrode sheet, the negative electrode sheet and the diaphragm can be automatically identified and detected based on the trained visual model, thereby improving the defect detection efficiency of the battery cell and avoiding false detection and missed detection caused by human factors. At the same time, after the defect is detected, the electrode sheet cutting mechanism 600 can automatically cut off the defective section, and after the detection is completed, the residual material cutting mechanism 700 can cut off the end section of the laminated structure of the battery cell, so as to facilitate the storage of the defective section and the end section together, which is convenient for the analyst to analyze and trace the cause of the defect 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 arranged on the frame 100. A slit is arranged between the two steering shafts 310 so that the laminated structure of the battery cell to be tested can pass through. The two sets of pressing mechanisms 320 are respectively arranged on the left and right sides of the two steering shafts 310. After passing through the two steering shafts 310, the laminated structure is separated into a positive electrode sheet part and a negative electrode sheet part. The positive electrode sheet part and the negative electrode sheet part are respectively deflected 180 degrees by the two steering shafts 310, changing from vertical belt running to horizontal belt running, and respectively pass through the two sets of pressing mechanisms 320 located on the left and right sides of the two steering shafts 310. The two sets of pressing mechanisms 320 are used to press the positive electrode sheet and the negative electrode sheet respectively, and provide traction forces in two different directions, left and right, to the positive electrode sheet and the negative electrode sheet respectively, so as to tear the laminated structure pressed together into the positive electrode sheet and the negative electrode sheet again, so that the two sets of electrode sheet photographing mechanisms 500 can take photos and scan the internal defects of the electrode sheet. Figure 3 In this embodiment, one of the two steering shafts 310 is slidably arranged on the frame through a slide rail, and the distance between the steering shaft 310 and the other steering shaft 310 can be adjusted through the slide rail to adapt to the stacking structure of battery cells with different thicknesses. In this embodiment, the structure of the pressing mechanism 320 and the transmission mechanism 400 is the same, both of which include an active roller 321 and a pressing roller 322. The active roller 321 is rotatably arranged on the frame 100. The active roller 321 can rotate under the drive of the active motor 324. The pressing roller 322 is rotatably arranged on the pressing drive mechanism 323. The pressing drive mechanism 323 is used to drive the pressing roller 322 to approach or move away from the active roller 321. In this embodiment, the pressing drive mechanism 323 includes a movable bracket, a guide rod and a pressing cylinder. The pressing roller 322 is rotatably arranged on the movable bracket. The movable bracket is slidably connected to the guide rod. The guide rod is fixedly arranged on the frame 100 through a supporting structure. The pressing cylinder is arranged on the frame 100, and the piston rod of the pressing cylinder is connected to the movable bracket. After the piston rod of the pressing cylinder is extended, the pressing roller 322 is driven to press on the active roller 321, and the positive and negative electrode sheets or the stacked structure before separation are pressed on the active roller 321, so that there is sufficient static friction between the electrode sheets and the active roller 321, so that the active motor 324 can apply sufficient traction to the electrode sheets when driving the active roller 321 to rotate.

[0039] Reference Figure 2 , Figure 3 and Figure 7In this embodiment, the electrode photographing mechanism 500 uses a line scan camera with a 4K resolution to scan the images of the front and back surfaces of the separated positive and negative electrode parts. The electrode photographing mechanism 500 includes a photographing 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 arranged above the photographing platform 350, and the lower line scan camera 540 and the lower light source assembly 530 are arranged below the photographing platform 350. A transparent window for light to pass through is arranged on the photographing platform 350, so that the light emitted by the lower light source assembly 530 can pass through the transparent window to irradiate the lower surface of the positive and negative electrode parts, and be reflected to the lower line scan camera 540 to form an image. In this embodiment, the upper line scan camera 510 and the lower line scan camera 540 are slidably connected to the frame 100 through an adjustment rail 560 vertically arranged on the frame 100, so that the height of the line scan camera from the photographing platform 350 can be adjusted by adjusting the rail 560 to adjust the field of view of the line scan camera. In this embodiment, the upper light source assembly 520 and the lower light source assembly 530 are both composed of two bar-shaped light sources, and the two bar-shaped light sources are arranged on the frame 100 through a supporting structure. The upper light source assembly 520 and the lower light source assembly 530 are also covered with a light shield, and a light shield door 570 that can be opened and closed is provided on the light shield to prevent the ambient light from affecting the detection.

[0040] Reference Figure 2 , Figure 5 and Figure 6In this embodiment, the structures of the electrode sheet cutting mechanism 600 and the residual material cutting mechanism 700 are basically the same, and both include a cutting platform 610, a cutter mechanism 620, and a cutter driving mechanism 630. The cutter driving mechanism 630 is arranged on one side of the cutting platform 610, and the stacked structure of the battery cell or the separated positive electrode sheet part and negative electrode sheet part pass through the cutting platform 610. Driven by the cutter driving mechanism 630, the cutter mechanism 620 can reciprocate along the surface of the cutting platform 610 in the width direction of the positive electrode sheet part, the negative electrode sheet part or the stacked structure to achieve cutting of the positive and negative electrode sheet parts or the stacked structure. In this embodiment, the cutter mechanism 620 includes a micrometer table 621 and a circular cutter 622 made of tungsten steel. The cutter 622 is rotatably arranged on the micrometer table 621, and the micrometer table 621 is used to adjust the gap between the cutter 622 and the corresponding cutting platform 610. The cutter drive mechanism 630 adopts a rodless cylinder, and the micrometer table 621 is set on the slider of the rodless cylinder. A cutting area is set on the cutting platform 610. The hardness of the cutting area is preferably higher than that of other areas to prevent scratches by the cutter 622 and to increase the service life of the cutter 622 platform. A row of vacuum suction holes 611 are set on both sides of the cutting area. The interior of the cutting platform 610 is provided with a cavity connected to the vacuum suction holes 611. The cavity is connected to a vacuum source such as a vacuum generator, so that the positive and negative electrode sheets or the laminated structure on the cutting platform 610 can be adsorbed during cutting to ensure stability during the cutting process. Figure 1 In this embodiment, waste bins 800 are provided on both sides of the frame 100 for recovering the positive electrode sheet and the negative electrode sheet without defects. A guide plate 612 is provided at one end of the cutting platform 610 of the electrode sheet cutting mechanism 600 facing away from the disassembly mechanism 300. The guide plate 612 is an arc-shaped plate, which smoothly guides the positive electrode sheet or the negative electrode sheet passing through the electrode sheet cutting mechanism 600 to the waste bin 800 below.

[0041] Reference Figure 1In this embodiment, a three-color alarm light 110 is also provided on the rack 100 to alarm the operator, so as to remind the operator to take away the defective sample segment cut when a defect is detected, and to remind the operator after the disassembly and detection are completed. A display screen 120 is provided on the rack 100 to display the images of the positive and negative electrode parts scanned in real time by four line scan cameras. A computer 130 is also provided on the rack 100 to store the images scanned by the line scan cameras, detect the defects on the stored images using the defect detection visual model, and control the actions of the disassembly mechanism 300, the transmission mechanism 400, the electrode cutting mechanism 600 and the residual material cutting mechanism 700 according to the detection results. The computer 130 is also used to connect peripheral devices such as a keyboard, a mouse and a barcode scanner to realize the functions of inputting equipment parameters, scanning the QR code on the battery cell to obtain the production information of the battery cell, and uploading the detection information to the MES system. Various control buttons are also provided on the rack 100 for manual control of the equipment.

[0042] Reference Figure 2 and Figure 3 Since the wound battery cells are mostly flattened before being put into the battery, in some embodiments, in order to avoid the difficulty of rotation of the oblate battery cells during the unwinding process, which causes the tension of the pole piece to fluctuate periodically, thereby improving the positioning accuracy of the image transmission mechanism 400 and the disassembly mechanism 300, a flipping auxiliary mechanism is provided in the battery cell holding basket 200. The flipping auxiliary mechanism 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 arranged on the frame 100, and the flipping suction cup 220 is arranged at the second end of the flipping swing arm 210. The flipping swing arm 210 can swing with the first end of the flipping swing arm 210 as the rotation center under the drive of the flipping drive mechanism 230. When the flipping suction cup 220 contacts the surface of the battery cell, it can absorb the surface of the battery cell in the battery cell holding basket 200, so that the battery cell can swing with the flipping swing arm 210, thereby assisting the oblate battery cell to rotate and unwind in the battery cell holding basket 200. In this embodiment, the material turning driving 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 battery cell defect detection device according to the embodiment of the present invention includes the following steps:

[0044] S100: The battery cell to be tested is placed on the equipment, and the lead of the stacked structure of the battery cell is transported to the disassembling mechanism 300 through the conveying mechanism 400, and the stacked structure is stripped into a positive electrode sheet part and a negative electrode sheet part under the traction of two sets of pressing mechanisms 320 of the separation mechanism;

[0045] S200: two sets of electrode sheet photographing mechanisms 500 respectively scan the front and back sides of the separated positive electrode sheet part and the negative electrode sheet part to obtain photos of the positive electrode sheet part and the negative electrode sheet part;

[0046] S300: identifying whether there are defects in the scanned photos of the positive electrode sheet and the negative electrode sheet through a visual recognition model trained by defect images of the positive electrode sheet and the negative electrode sheet, and recording the location and size parameters of the defects when defects are identified;

[0047] S400: Calculate the cutting position of the electrode sheet cutting mechanism 600 according to the position and size parameters of the scanned defect, and drive the electrode sheet cutting mechanism 600 to cut the positive electrode sheet part or the negative electrode sheet part when the positive electrode sheet part or the negative electrode sheet part moves to the corresponding position, stop the disassembly mechanism 300 and the conveying mechanism 400 after the cutting is completed, and issue an alarm to remind the operator to take away the cut defective sample segment;

[0048] S500: After the defective sample segment is taken away, the disassembling mechanism 300 and the conveying mechanism 400 are restarted, and steps S200 to S400 are repeated until the unwinding length of the battery cell reaches a preset value;

[0049] S600: After the unwinding length of the battery cell reaches a preset value, the disassembling mechanism 300 and the conveying mechanism 400 are stopped, and the residual material cutting mechanism is driven to cut the stacking structure of the battery cell to obtain the end section of the stacking 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.

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

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

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

[0053] S420: Extending the length positions of the two ends of the defective area by a preset length on both sides in the length direction to obtain the cutting positions of the two ends of the defective sample segment;

[0054] S430: monitoring the transmission distances of the two pressing and feeding mechanisms 320 in the disassembling mechanism 300, and when the transmission distance of the corresponding pressing and feeding mechanism 320 is equal to the cutting position, pausing the disassembling mechanism 300 and the conveying mechanism 400, and driving the electrode sheet cutting mechanism 600 to cut the positive electrode sheet part or the negative electrode sheet part once;

[0055] S440: After the cutting positions at both ends of the defective sample segment are cut, the disassembling mechanism 300 and the conveying mechanism 400 are stopped, and an alarm is issued to remind the operator to take away the cut defective sample segment.

[0056] Taking the positive electrode sheet as an example, when the electrode photographing mechanism 500 on the positive electrode sheet detects that there is a defect on the surface of the positive electrode sheet or the diaphragm, the length position of the two ends of the defect is identified through the visual model, and the preset length, such as 100 mm, is extended outward according to the length position of the two ends of the defect to calculate the cutting position. When the transport length of the pressing mechanism 320 of the disassembly mechanism 300 reaches the cutting position, the disassembly mechanism 300 and the conveying mechanism 400 are suspended, and the electrode cutting mechanism 600 on the positive electrode sheet is driven to cut the positive electrode sheet. After the 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 driven 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 positions of the positive and negative electrode parts scanned by the two sets of electrode photographing mechanisms 500 should be based on the unwinding length corresponding to the cutter 622 on the electrode cutting mechanism 600 on the same side, so that the cutting position can be directly calculated by the positions of the two ends of the defect in the photo.

[0057] It can be understood that if there are defects with overlapping length position ranges on the front and back sides of the positive electrode sheet, in order to ensure the integrity of the defects on the defective sample segment after cutting, when calculating the cutting position, the maximum and minimum values ​​of the length positions at both ends of all defects on the front and back sides of the positive electrode sheet should be used as the basis for outward expansion to calculate the cutting position.

[0058] It should be noted that in the description of the present invention, if there are any orientation descriptions, such as up, down, front, back, left, right, etc., the orientations or positional relationships indicated are all based on the orientations or positional relationships shown in the drawings. They are only for the convenience of describing the present 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 cannot be understood as a limitation on the present invention.

[0059] In the description of the present invention, "several" means one or more, "more" means two or more, "greater than", "less than", "exceed" etc. are understood to exclude the number itself, and "above", "below", "within" etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used to distinguish the technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0060] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0061] The above-mentioned embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and substitutions made by technicians in this field on the basis of the present invention shall fall within the scope of protection required 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), arranged on the frame (100) and used for holding battery cells to be tested; A disassembly mechanism (300) is arranged on the frame (100) and is used to separate the positive electrode sheet part and the negative electrode sheet part of the battery cell to be tested, and transport the separated positive electrode sheet part and the negative electrode sheet part in two different directions; A conveying mechanism (400) is arranged on the frame (100), between the disassembling mechanism (300) and the battery cell holding basket (200), and is used to transport the electrode piece of the battery cell to be tested to the disassembling mechanism (300); Two sets of electrode piece photographing mechanisms (500) are arranged on the frame (100), and the two sets of electrode piece photographing mechanisms (500) are respectively arranged on the tape paths of the separated positive electrode piece part and the negative electrode piece part, and are used to collect and scan images of the front and back sides of the separated positive electrode piece part and the negative electrode piece part; Two sets of electrode sheet cutting mechanisms (600) are arranged on the frame (100), and the two sets of electrode sheet cutting mechanisms (600) are respectively arranged behind the two sets of electrode sheet photographing mechanisms (500) and are used to cut the separated positive electrode sheet parts and negative electrode sheet parts; The residual material cutting mechanism (700) is arranged on the frame (100), between the battery cell holding basket (200) and the conveying mechanism (400), and is used for cutting the stacked structure of the battery cell to be inspected.

2. The defect detection device for wound battery cells according to claim 1, characterized in that: The disassembling mechanism (300) comprises two steering shafts (310) and two groups of pressing mechanisms (320). The two steering shafts (310) are rotatably arranged on the frame (100). A slit is arranged between the two steering shafts (310) so that the laminated structure of the battery cell to be tested can pass through. The two groups of pressing mechanisms (320) are arranged on the left and right sides of the two steering shafts (310), respectively. After passing through the two steering shafts (310), the laminated structure is separated into a positive electrode sheet part and a negative electrode sheet part. The separated positive electrode sheet part and negative electrode sheet part pass through the two groups of pressing mechanisms (320) respectively. The pressing mechanisms (320) are used to pull the separated positive electrode sheet part and negative electrode sheet part to move in two different directions. Under the action of the pulling force of the two groups of pressing mechanisms (320), the laminated structure of the battery cell to be tested is torn apart and separated into a positive electrode sheet part and a negative electrode sheet part.

3. The defect detection device for wound battery cells according to claim 2, characterized in that: The two groups of the pressing and feeding mechanisms (320) and the conveying mechanisms (400) have the same structure, and both include an active roller (321) and a press roller (322). The active roller (321) is rotatably arranged on the frame (100). The active roller (321) can be rotated under the drive of an active motor (324). The press roller (322) is rotatably arranged on a press driving mechanism (323). The press driving mechanism (323) is used to drive the press roller (322) to approach or move away from the active roller (321).

4. The defect detection device for wound battery cells according to claim 1, characterized in that: The pole piece photographing mechanism (500) comprises a photographing platform (350), an upper line scanning camera (510), an upper light source assembly (520), a lower line scanning camera (540) and a lower light source assembly (530); the photographing platform (350) is horizontally arranged on the frame (100); a transparent window for light to pass through is arranged on the photographing platform (350); the upper line scanning camera (510) and the upper light source assembly (520) are arranged directly above the photographing platform (350); and the lower line scanning camera (540) and the lower light source assembly (530) are arranged directly below the photographing platform (350).

5. The defect detection device for wound battery cells according to claim 4, characterized in that: The upper line scan camera (510) and the lower line scan camera (540) are both slidably arranged on the frame (100) via an adjustable slide rail (560); the upper line scan camera (510) and the lower line scan camera (540) can slide in a vertical direction along the adjustable slide rail (560).

6. The defect detection device for wound battery cells according to claim 1, characterized in that: The two groups of the electrode sheet cutting mechanisms (600) and the residual material cutting mechanisms (700) have the same structure, and both include a cutting platform (610), a cutting mechanism (620) and a cutting drive mechanism (630). The cutting drive mechanism (630) is arranged on one side of the cutting platform (610). The stacked structure of the battery cell to be tested, and the positive electrode sheet part or the negative electrode sheet part after the stacked structure is separated, pass through the cutting platform (610). The cutting mechanism (620) can be driven by the cutting drive mechanism (630) to reciprocate along the surface of the cutting platform (610) in the width direction of the positive electrode sheet part, the negative electrode sheet part or the stacked structure.

7. The defect detection device for wound battery cells according to claim 1, characterized in that: The cutting knife mechanism (620) comprises a micrometer table (621) and a circular cutting knife (622), wherein the cutting knife (622) is rotatably arranged on the micrometer table (621), the micrometer table (621) is connected to the cutting drive mechanism, and the micrometer table (621) is used to adjust the gap between the cutting knife (622) and the corresponding cutting platform (610), and a cutting area is arranged on the cutting platform (610), and a row of vacuum suction holes (611) are arranged on both sides of the cutting area, and a cavity connected to the vacuum suction hole (611) is arranged inside the cutting platform (610), and the cavity is connected to a vacuum source.

8. The defect detection device for wound battery cells according to claim 1, characterized in that: A material turning auxiliary mechanism is also arranged above the battery cell holding basket (200), and the material turning auxiliary mechanism comprises a material turning swing arm (210), a material turning driving mechanism (230) and a material turning suction cup (220). The first end of the material turning swing arm (210) is rotatably arranged on the frame (100), and the material turning suction cup (220) is arranged at the second end of the material turning swing arm (210). The material turning swing arm (210) can swing with the first end of the material turning swing arm (210) as the rotation center under the drive of the material turning driving mechanism (230), and the material turning suction cup (220) can absorb the surface of the battery cell located in the battery cell holding basket (200).

9. A detection method for a defect detection device for a wound battery cell according to any one of claims 1 to 8, characterized in that: The steps include: S100: placing the battery cell to be tested on the equipment, so that the lead of the stacked structure of the battery cell is transported to the disassembly mechanism (300) through the conveying mechanism (400), and the stacked structure is stripped into a positive electrode sheet part and a negative electrode sheet part under the traction of two sets of pressing mechanisms (320) of the separation mechanism; S200: two sets of electrode sheet photographing mechanisms (500) respectively scan the front and back sides of the separated positive electrode sheet part and the negative electrode sheet part to obtain photos of the positive electrode sheet part and the negative electrode sheet part; S300: Identify whether there are defects in the scanned photos of the positive electrode sheet and the negative electrode sheet through a visual model trained with defect images of the positive electrode sheet, the negative electrode sheet and the separator, and record the location and size parameters of the defects when defects are identified; S400: calculating the cutting position of the electrode sheet cutting mechanism (600) according to the position and size parameters of the scanned defect, and driving the electrode sheet cutting mechanism (600) to cut the positive electrode sheet part or the negative electrode sheet part when the positive electrode sheet part or the negative electrode sheet part moves to the corresponding position, stopping the disassembly mechanism (300) and the conveying mechanism (400) after the cutting is completed, and issuing an alarm to remind the operator to take away the cut defective sample segment; S500: After the defective sample segment is removed, the disassembling mechanism (300) and the conveying mechanism (400) are restarted, and steps S200 to S400 are repeated until the unwinding length of the battery cell reaches a preset value; S600: After the unwinding length of the battery cell reaches a preset value, the disassembling mechanism (300) and the conveying mechanism (400) are stopped, and the residual material cutting mechanism is driven to cut the laminated structure of the battery cell to obtain the end section of the laminated structure of the battery cell. After the cutting is completed, an alarm is issued and the operator takes away the end section, and stores the end section together with the defective sample section.

10. The detection method according to claim 9, characterized in that: The step S400 includes: S410: Obtain the length positions of both ends of the defect area; S420: Extending the length positions of the two ends of the defective area by a preset length on both sides in the length direction to obtain the cutting positions of the two ends of the defective sample segment; S430: monitoring the transmission distances of the two pressing and feeding mechanisms (320) in the disassembling mechanism (300); when the transmission distance of the corresponding pressing and feeding mechanism (320) is equal to the cutting position, pausing the disassembling mechanism (300) and the conveying mechanism (400), and driving the electrode sheet cutting mechanism (600) to cut the positive electrode sheet part or the negative electrode sheet part once; S440: After the cutting positions at both ends of the defective sample segment are cut, the disassembling mechanism (300) and the conveying mechanism (400) are stopped, and an alarm is issued to remind the operator to take away the cut defective sample segment.

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