Coating apparatus, coating die, and coating control method

Abstract

The application discloses a coating equipment, a coating die and a coating control method, which comprise a coating roller, a scratch defect detection assembly, a coating die and a first driving mechanism. The coating roller is suitable for being connected with a current collector. The scratch defect detection assembly is located at the adjacent side of the coating roller, and the detection end of the scratch defect detection assembly faces the current collector. The coating die is provided with a base, a first die, a second die and the first driving mechanism. The first die is installed on the base and is internally provided with a slurry passage. The second die is located above the first die. A feeding gap which is communicated with the slurry passage is arranged between the second die and the first die. The end of the feeding gap is provided with a lip. A coating gap is arranged between the lip and the coating roller. The first driving mechanism is connected with the second die and is used for driving the second die to move relative to the first die along the extension direction of the feeding gap, so as to increase the coating gap. The application can automatically retreat the die in the case of detecting scratch abnormalities, and realizes automatic removal of the blocking object.

Description

Technical Field

[0001] This invention relates to the field of lithium-ion battery manufacturing technology, and in particular to a coating equipment, a coating die, and a coating control method. Background Technology

[0002] Battery technology involves methods or devices for directly converting chemical energy into electrical energy, such as battery packs. In lithium-ion battery manufacturing, the coating of positive and negative electrodes is a crucial process. This process typically utilizes a slit-type extrusion coating die to evenly apply a prepared slurry to the surface of a continuously moving current collector (also known as the substrate or foil). However, during the coating process, obstructions such as large particles or agglomerates can become trapped in the coating gap between the die lip and the current collector, resulting in white streaks on the current collector surface. Currently, the industry practice is to manually clean large particles or agglomerates after stopping the machine and removing the die, which easily wastes materials and reduces production efficiency. Summary of the Invention

[0003] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a coating device, a coating die head, and a coating control method, which can automatically retract the die head when abnormal scratches are detected, thereby automatically removing obstructions.

[0004] On one hand, embodiments of the present invention provide a coating apparatus suitable for coating a current collector, comprising: Coating roller, adapted to connect to the current collector; A scratch defect detection component is located on the adjacent side of the coating roller, with the detection end of the scratch defect detection component facing the current collector; A coating die head is provided with a base, a first die head, a second die head, and a first drive mechanism. The first die head is mounted on the base and has a slurry channel inside. The second die head is located above the first die head. A feeding gap communicating with the slurry channel is provided between the second die head and the first die head. A lip is provided at the end of the feeding gap. A coating gap is provided between the lip and the coating roller. The first drive mechanism is connected to the second die head and is used to drive the second die head to move relative to the first die head along the extension direction of the feeding gap to increase the coating gap.

[0005] According to some embodiments of the present invention, the first mold head and the second mold head are provided with a first track-type guide portion and are slidably connected through the first track-type guide portion; Alternatively, a support member may be provided on the base, and the support member and the second mold head may be provided with a second track-type guide portion, and slidably connected through the second track-type guide portion.

[0006] According to some embodiments of the present invention, a gasket is provided at the bottom of the second mold head and is connected to the first mold head through the gasket. Both the surface of the gasket and the surface of the first mold head are provided with a wear-resistant coating.

[0007] According to some embodiments of the present invention, the second die head is connected to an elastic pre-compression assembly, the elastic pre-compression assembly being adapted to apply a clamping force toward the first die head to the second die head.

[0008] According to some embodiments of the present invention, the elastic preload assembly includes a first fastening rod, a first sliding member, and a first elastic member. Both the first die head and the second die head are provided with a first clearance extending along the relative displacement direction. The first sliding member is slidably mounted on the second die head. The first fastening rod passes through the first clearance and the first sliding member, and a limiting portion is provided at the end of the first fastening rod. The first elastic member is sleeved on the first fastening rod, and its two ends abut against the limiting portion and the first sliding member, respectively.

[0009] According to some embodiments of the present invention, the coating apparatus further includes a displacement sensor located adjacent to the lip and adapted to detect the movement distance of the second die head.

[0010] According to some embodiments of the present invention, the movement distance of the second mold head relative to the first mold head is in the range of [1, 50] micrometers.

[0011] On the other hand, embodiments of the present invention provide a coating die head, comprising: Base; A first mold head is installed on the base, and a slurry channel is provided inside the first mold head; The second die head is located above the first die head, and a feeding gap communicating with the slurry channel is provided between the second die head and the first die head; A first drive mechanism is connected to the second die head and is used to drive the second die head to move relative to the first die head along the extension direction of the feeding gap, so as to increase the exposed area of ​​the top of the first die head.

[0012] According to some embodiments of the present invention, the second die head is connected to an elastic pre-compression assembly, the elastic pre-compression assembly being adapted to apply a clamping force toward the first die head to the second die head.

[0013] In another aspect, embodiments of the present invention provide a coating control method, applied to the aforementioned coating equipment, comprising: During the coating process of the current collector, the current collector is subjected to scratch defect detection by the scratch defect detection component to obtain a first detection result; If the first detection result indicates the presence of scratch defects, the first drive mechanism drives the second die head to move a preset distance relative to the first die head in a direction away from the coating roller; The current collector is subjected to scratch defect detection by the scratch defect detection component to obtain a second detection result; If the second detection result indicates that there are no scratches or defects, the second mold head is reset by the first drive mechanism.

[0014] The embodiments of the present invention have at least the following beneficial effects: During the coating process, the scratch defect detection component can detect scratches on the current collector. When a scratch defect is detected, the first drive mechanism drives the second die head to move relative to the first die head, thereby increasing the coating gap between the second die head and the coating roller. This allows the obstructing material to be washed away by the slurry as the current collector rotates. When the scratch defect detection component detects no scratch defects in the current collector, the first drive mechanism drives the second die head to reset. The entire process does not require machine downtime, which helps to improve the continuity of production and the uptime of equipment, significantly reduces material waste, and helps to reduce production costs.

[0015] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0016] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of the coating equipment according to an embodiment of the present invention; Figure 2 This is a structural diagram of the coating equipment according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the coating die head of the coating equipment according to an embodiment of the present invention; Figure 4 This is a flowchart illustrating the steps of the coating control method according to an embodiment of the present invention.

[0017] Figure label: Current collector 10, jamming device 20, coating roller 100, scratch defect detection component 200, coating die head 300, base 310, first die head 320, second die head 330, first drive mechanism 340, slurry channel 321, material feeding gap 322, coating gap 323, gasket 350, elastic pre-compression component 360, first fastening rod 361, limiting part 362, first sliding member 363, first elastic member 364. Detailed Implementation

[0018] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0019] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0020] In the description of this invention, "several" means one or more, "multiple" means two or more, "greater than," "less than," "exceeding," etc. are understood to exclude the stated number, and "above," "below," "within," etc. are understood to include the stated number. If "first," "second," etc. are used in the description, they are 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 the order of the indicated technical features.

[0021] In the description of this invention, unless otherwise explicitly defined, terms such as "set", "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.

[0022] The following is the optimized patent content description, with more standardized language, clearer logic, and in line with the professional writing style of patent documents: Currently, the mainstream process in lithium-ion battery electrode coating uses a slot die 300 to uniformly apply pre-prepared slurry to the surface of a continuously moving current collector 10. This process typically requires coating precision control at the micrometer level.

[0023] However, under low areal density (<5 mg / cm²) coating conditions, the gap (i.e., GAP value) between the die and the coating roller is small (typically <50 μm). When there are obstructions 20 in the slurry, such as large particles or agglomerates, since the particle size of the obstructions 20 is generally greater than 50 μm, i.e. greater than the GAP value, these particles are very likely to get stuck at the coating gap 323 between the die lip and the substrate after flowing out through the narrow slit inside the die. The stuck solid particles will exert a continuous scratching effect on the coating that is forming, thereby forming longitudinal white streak-like scratch defects on the surface of the current collector 10.

[0024] In existing technology, once coating scratches are detected, the standard procedure is to immediately stop the operation of the entire coating line, move the die head backward as a whole (i.e., demolding operation), and have the operator manually spray and wipe the die head lip with copper sheet or special solvent. After confirming that there are no particles stuck, the die is reinserted and the gap is adjusted to resume the coating operation.

[0025] The above-mentioned processing method has the following significant industry pain points: First, after each shutdown for maintenance, it is necessary to repeat the processes such as conveyor belt operation, tool setting, and process debugging, resulting in a large amount of waste of substrate and high-value slurry; Second, frequent shutdowns for debugging lead to a significant decrease in the overall equipment effectiveness (OEE) of the coating equipment, which seriously restricts the output capacity of large-scale, high-efficiency production lines for lithium batteries.

[0026] Therefore, this embodiment provides a coating device, a coating die 300, and a coating control method, which can achieve online automatic removal of obstructions 20 without stopping the operation of the coating line or retracting the overall structure of the coating die 300.

[0027] Please refer to Figure 1 and Figure 2 The coating equipment disclosed in this embodiment is suitable for coating a current collector 10. The coating equipment includes a coating roller 100, a scratch defect detection component 200, and a coating die 300. The coating roller 100 is suitable for connecting to the current collector 10, that is, the current collector 10 can rotate synchronously with the coating roller 100. The scratch defect detection component 200 is located on the adjacent side of the coating roller 100, and the detection end of the scratch defect detection component 200 faces the current collector 10. The scratch defect detection component 200 is suitable for performing scratch defect detection on the current collector 10. The scratch defect detection component 200 includes a detection camera, the lens of which faces the current collector 10 and captures an image of the current collector 10. The captured image is then transmitted to an image processing component such as a controller or a host computer. The image processing component performs scratch detection on the image using an image recognition algorithm. The scratch detection algorithm is not the focus of this embodiment. Existing image recognition algorithms can be used, such as image binarization, morphological operations and edge detection. The relevant image recognition algorithms have been fully disclosed in the prior art, and will not be described in detail in this embodiment.

[0028] Please refer to Figure 1The coating die 300 is provided with a base 310, a first die 320, a second die 330, and a first drive mechanism 340. The first die 320 is mounted on the base 310 and has a slurry channel 321 inside. The second die 330 is located above the first die 320; therefore, the first die 320 is also called the lower die, and the second die 330 is also called the upper die. A feeding gap 322 communicating with the slurry channel 321 is provided between the second die 330 and the first die 320. The end of the feeding gap 322 has a lip, and a coating gap 323 is provided between the lip and the coating roller 100. The first drive mechanism 340 is connected to the second die 330 and is used to drive the second die 330 along the extension direction of the feeding gap 322 (e.g., ...). Figure 1 (As shown in the front-to-back direction) moves relative to the first die head 320 to increase the coating gap 323.

[0029] In use, the current collector 10 is mounted on the coating roller 100 and can rotate synchronously with the coating roller 100 to achieve continuous coating operation. The coating slurry is sprayed from the lip through the slurry channel 321 and the feed gap 322 to coat the surface of the current collector 10. A coating gap 323 is provided between the lip and the coating roller 100, that is, a coating gap 323 is provided between the lip and the current collector 10. The coating gap 323 is usually a micron-level gap. When there is an obstruction 20 in the slurry, the obstruction 20 will flow out of the lip through the feed gap 322 along with the slurry. However, since the size of the obstruction 20 is larger than the coating gap 323, the obstruction 20 cannot pass smoothly and is stuck at the coating gap 323. The obstruction 20 exerts a continuous scraping effect on the surface of the current collector 10, thereby forming white streaks on the surface of the current collector 10.

[0030] After the scratch defect detection component 200 detects white streaks, the first drive mechanism 340 moves the second die head 330 away from the coating roller 100, thereby increasing the gap between the second die head 330 and the coating roller 100, thus exposing a larger area at the lip on the upper side of the first die head 320. During this process, the coating operation continues, and the slurry continuously flows out from the lip. The stuck obstruction 20 is smoothly flushed away from the coating gap 323 under the combined traction of the slurry flow and the movement of the current collector 10, thereby achieving automatic removal of the obstruction 20. When the obstruction 20 is removed, the surface of the current collector 10 returns to normal, the scratch defect detection component 200 no longer detects white streaks, the first drive mechanism 340 drives the second die head 330 to reset, and the coating operation returns to normal.

[0031] The first drive mechanism 340 uses a micron-level high-precision motor, which can achieve micron-level high-precision displacement control of the second mold head 330, avoiding excessive misalignment between the lips of the second mold head 330 and the first mold head 320. Moreover, the misalignment response time between the second mold head 330 and the first mold head 320 reaches the millisecond level, which has minimal impact on the foil tension and surface density fluctuations in the normal coating section, thereby achieving online non-stop self-healing of coating defects.

[0032] That is, during the coating process, the scratch defect detection component 200 can detect scratches on the current collector 10. When a scratch defect is detected, the first drive mechanism 340 drives the second die head 330 to move relative to the first die head 320, thereby increasing the coating gap 323 between the second die head 330 and the coating roller 100, so that the obstruction 20 can be washed away by the slurry as the current collector 10 rotates. When the scratch defect detection component 200 detects that there are no scratch defects in the current collector 10, the first drive mechanism 340 drives the second die head 330 to reset. The whole process does not require stopping the machine, which is conducive to improving the continuity of production and the utilization rate of equipment, greatly reducing material waste, and reducing production costs.

[0033] While the above-described example solution can essentially achieve online, non-stop self-healing of coating scratch defects, this embodiment also provides optional optimization schemes to further improve the reliability and accuracy of coating scratch defect self-healing. Specifically, by providing motion guidance to the second mold head 330 during its movement, the positional deviation of the second mold head 330 in unexpected directions can be limited, thereby improving the positional accuracy and motion reliability of the reciprocating motion of the second mold head 330.

[0034] In the above scheme, the first drive mechanism 340 is connected to the second die head 330, enabling the second die head 330 to reciprocate along a preset linear direction. However, due to factors such as the structural form and assembly errors of the first drive mechanism 340, the second die head 330 inevitably experiences a slight offset during movement. In conventional applications, the slight offset caused by the first drive mechanism 340 has a small impact on the overall motion accuracy and is usually negligible. However, in the application scenario involved in this embodiment, the second die head 330 requires micron-level displacement adjustment. In this case, the aforementioned slight offset will cause a decrease in the relative positional accuracy between the second die head 330 and the first die head 320, thereby causing a change in the size of the feeding gap 322 between them. Fluctuations in the size of the feeding gap 322 will directly affect the feeding rate and feeding stability of the slurry, ultimately adversely affecting the uniformity of the coating thickness and the coating quality.

[0035] Based on the above analysis, a motion guide structure is introduced during the movement of the second mold head 330 to precisely constrain and guide the movement trajectory of the second mold head 330. This has important technical value for ensuring the positional accuracy between the second mold head 330 and the first mold head 320, maintaining the stability of the material supply gap 322 size, and ensuring the uniformity of slurry supply. It is also an optimization direction for further improving the self-healing effect of coating scratch defects.

[0036] To achieve motion guidance, in some application examples, the first mold head 320 and the second mold head 330 are provided with a first track-type guide portion, and are slidably connected through the first track-type guide portion. Specifically, one of the first mold head 320 and the second mold head 330 is provided with a first slide rail, and the other of the first mold head 320 and the second mold head 330 is provided with a corresponding first slide groove. The first slide rail and the first slide groove cooperate to form the first track-type guide portion, and the first mold head 320 and the second mold head 330 move along a preset direction under the guidance of the first slide rail and the first slide groove. The machining accuracy of the first slide rail and the first slide groove is within a preset error range, and the contact surfaces of the first slide rail and the first slide groove are both set as smooth planes to reduce motion friction and enable smoother relative movement between the first mold head 320 and the second mold head 330.

[0037] Alternatively, in other application examples, a support member is provided on the base 310, and the support member and the second die head 330 are provided with a second track-type guide portion, which is slidably connected to each other. Specifically, the second die head 330 is connected to the base 310, at least one of the second die head 330 and the base 310 is provided with a second slide rail, and at least two of the second die head 330 and the base 310 are provided with a second slide groove. The second slide rail and the second slide groove cooperate to form the second track-type guide portion, and the first die head 320 and the second die head 330 move in a preset direction under the guidance of the second slide rail and the second slide groove. Unlike the above application example, this application example sets the partial structure of the second track-type guide portion (such as the second slide rail or the second slide groove) on the base 310, which can avoid modifying the first die head 320, reduce the impact on the feeding gap 322, and is beneficial to the stability of the size of the feeding gap 322. It should be noted that the base 310 is provided with an upwardly extending connecting member to connect to the second die head 330.

[0038] In the above scheme, the second die head 330 can be moved and adjusted relative to the first die head 320 to achieve dynamic adjustment of the feeding gap 322 size. However, during long-term operation, the contact surface between the second die head 330 and the first die head 320 will wear due to repeated relative sliding, resulting in a gradual decrease in the surface accuracy of the contact surface, which in turn causes the actual size of the feeding gap 322 to deviate from the design value. The deviation in the size of the feeding gap 322 will directly affect the feeding rate and uniformity of the slurry, ultimately adversely affecting the thickness consistency and coating quality of the coating layer.

[0039] Please refer to Figure 1 To improve the reliability and dimensional stability of the coating die 300 under long-term operating conditions, a shim 350 is provided at the bottom of the second die 330, and the second die 330 is connected to the first die 320 via the shim 350. Both the surface of the shim 350 and the surface of the first die 320 are coated with a wear-resistant coating. The shim 350 is fixedly connected to the bottom of the second die 330, and the surface of the shim 350 facing the first die 320 can contact the corresponding surface of the first die 320, thus creating a feeding gap 322 between the two dies. When the second die 330 is displaced relative to the first die 320, the shim 350 moves synchronously with the second die 330, resulting in relative sliding between the shim 350 and the first die 320. Given that the displacement adjustment accuracy of the second die head 330 in this application is at the micrometer level, even if a small amount of wear occurs on the contact surface between the shim 350 and the first die head 320, it is enough to cause a significant change in the size of the feeding gap 322, thereby causing the accumulation of displacement error and affecting the position repeatability accuracy of the reciprocating motion of the second die head 330.

[0040] Based on the above analysis, this embodiment provides a first wear-resistant coating on the contact surface of the gasket 350 and a second wear-resistant coating on the contact surface where the first die 320 mates with the gasket 350. By providing wear-resistant coatings on the two relatively sliding contact surfaces, the wear resistance of the contact surface between the gasket 350 and the first die 320 can be effectively enhanced, reducing surface wear caused by long-term relative sliding, thereby reducing displacement errors caused by wear. This helps ensure the positional repeatability accuracy of the second die 330 during multiple reciprocating movements, and improves the overall reliability and service life of the coating die 300.

[0041] Optionally, the first and / or second wear-resistant coatings can be DLC (Diamond Like Carbon) coatings. DLC coatings have high hardness, low coefficient of friction, and good chemical stability, which can further reduce the sliding friction resistance between the gasket 350 and the first die head 320 while ensuring wear resistance, thus improving the smoothness and accuracy of the micro-displacement adjustment of the second die head 330.

[0042] In other alternative embodiments, the wear-resistant coating can also be a chromium coating. Chromium coatings also have good hardness and wear resistance, and the process is mature and the cost is controllable, making them suitable for applications that require a certain level of wear resistance but have relatively low requirements for the coefficient of friction.

[0043] Ideally, the second die head 330 should move along a preset straight line in the horizontal plane to move away from the coating roller 100 or reset. However, as mentioned above, due to factors such as the structural form of the first drive mechanism 340 and assembly errors, the second die head 330 will experience a slight deviation in the longitudinal direction during the process of the first drive mechanism 340 driving the second die head 330 to move.

[0044] In typical mechanical motion control scenarios, the amplitude of the aforementioned longitudinal slight offset is small and its impact on overall motion accuracy is negligible. However, in the application scenario of the coating die 300 involved in this embodiment, the material supply gap 322 between the first die 320 and the second die 330 is a micrometer-level gap, requiring extremely high relative positional accuracy. When the second die 330 experiences a slight longitudinal offset during movement, this offset causes the actual material supply gap 322 between the second die 330 and the first die 320 to deviate from the preset value, specifically manifested as an unexpected increase in the material supply gap 322. The increase in the material supply gap 322 will directly change the flow field distribution of the slurry in the supply channel, thereby affecting the slurry supply rate and supply uniformity, ultimately leading to uneven coating thickness defects on the surface of the current collector 10, severely affecting the coating quality.

[0045] Therefore, please refer to Figure 2 In this embodiment, the second die head 330 is connected to an elastic preload assembly 360, which is adapted to apply a clamping force towards the first die head 320 to the second die head 330. The elastic preload assembly 360 is used to apply a continuous elastic preload to the second die head 330, causing the second die head 330 to tend to move towards the first die head 320. Through the action of the elastic preload, during the displacement adjustment process of the second die head 330 relative to the first die head 320, the elastic preload assembly 360 can compensate for the slight longitudinal offset caused by the first drive mechanism 340 in real time, so that the contact fit between the second die head 330 and the first die head 320 remains stable, thereby effectively suppressing the unexpected changes in the feeding gap 322 caused by longitudinal offset, and ensuring the stability and consistency of the feeding gap size.

[0046] In some application examples, the elastic preload assembly 360 includes a first fastening rod 361, a first sliding member 363, and a first elastic member 364. The first die head 320 and the second die head 330 are both provided with a first clearance extending in the relative displacement direction. The first sliding member 363 is slidably mounted on the second die head 330. The first fastening rod 361 passes through the first clearance and the first sliding member 363, and the end of the first fastening rod 361 is provided with a limiting part 362. The first elastic member 364 is sleeved on the first fastening rod 361, and its two ends abut against the limiting part 362 and the first sliding member 363, respectively. The limiting part 362 and the first sliding member 363 cooperate to limit the elastic member on the first fastening rod 361. The limiting part 362 can be an external component such as a washer 350, a pin, or a nut, or it can be a protrusion provided on the first fastening rod 361. The first elastic member 364 is adapted to apply an elastic preload to the first sliding member 363, thereby making the second mold head 330 and the first mold head 320 fit tightly together. The contact surfaces between the first sliding member 363 and the second mold head 330 are both smooth surfaces to reduce sliding friction and make the sliding of the second mold head 330 smoother. In some other application examples, the elastic preload assembly 360 uses a disc spring bolt, which helps to reduce design costs by using existing components.

[0047] In the above scheme, basic control of the movement stroke of the second die head 330 can be achieved by embedding an encoder in the first drive mechanism 340 or by setting a limit mechanism at a preset stroke endpoint. However, in order to further improve the accuracy of the movement control of the second die head 330, especially to meet the stringent requirements for positional accuracy in micron-level displacement adjustment scenarios, the coating equipment also includes a displacement sensor. The displacement sensor is located adjacent to the lip and is suitable for detecting the movement distance of the second die head 330. The displacement sensor is a high-precision displacement sensor used to dynamically monitor the displacement of the lip of the second die head 330 relative to the lip of the first die head 320, so as to perform closed-loop control of the linear displacement of the second die head 330, thereby improving the motion control accuracy.

[0048] The first drive mechanism 340, in conjunction with the displacement sensor, can achieve high-precision motion control. The second mold head 330 moves relative to the first mold head 320 in the range of [1, 50] micrometers. That is, the second mold head 330 can move within the range of 1 to 50 micrometers to achieve high-precision movement at the micrometer level, so as to automatically remove obstructions 20 with a size of 1 to 50 micrometers.

[0049] Please refer to Figure 1 and Figure 2This embodiment also provides a coating die head 300, including a base 310, a first die head 320, a second die head 330, and a first driving mechanism 340. The first die head 320 is mounted on the base 310, and a slurry channel 321 is provided inside the first die head 320; the second die head 330 is located above the first die head 320, and a feeding gap 322 communicating with the slurry channel 321 is provided between the second die head 330 and the first die head 320; the first driving mechanism 340 is connected to the second die head 330 and is used to drive the second die head 330 to move relative to the first die head 320 along the extension direction of the feeding gap 322, so as to increase the exposed area of ​​the top of the first die head 320.

[0050] In related technologies, the first die head 320 and the second die head 330 are usually fixedly connected, and there is no relative movement between them. Therefore, the structural shape of the lip at the end of the feeding gap 322 remains unchanged during the coating process. When obstructions such as particulate impurities or dried slurry lumps become stuck at the lip during the coating process, due to the fixed lip structure and the small size of the coating gap 323, the obstructions are difficult to be washed away by the slurry on their own, often requiring a shutdown for cleaning, which affects the continuity of production. In this embodiment, the coating die head 300 drives the second die head 330 to make a slight displacement adjustment relative to the first die head 320 through the first driving mechanism 340, which can dynamically change the structural shape at the lip of the coating die head 300. Specifically, it increases the exposed area of ​​the top of the first die head 320, thereby creating a larger clearance space in the lip area. This clearance provides a more ample channel for the obstruction 20 stuck at the lip, so that it can be smoothly flushed away from the lip area by the flow of slurry, thus realizing the online self-cleaning function of the obstruction 20 at the lip.

[0051] When the coating die head 300 of this embodiment is applied to the coating equipment, during the coating process, the scratch defect detection component 200 can perform scratch detection on the current collector 10. When a scratch defect is detected, the first drive mechanism 340 drives the second die head 330 to move relative to the first die head 320, thereby increasing the coating gap 323 between the second die head 330 and the coating roller 100, so that the obstruction 20 can be washed away by the slurry as the current collector 10 rotates. When the scratch defect detection component 200 detects that there is no scratch defect in the current collector 10, the first drive mechanism 340 drives the second die head 330 to reset. The whole process does not require stopping the machine, which is conducive to improving the continuity of production and the utilization rate of the equipment, greatly reducing material waste, and helping to reduce production costs.

[0052] Please refer to Figure 3The second die head 330 is connected to an elastic preload assembly 360, which is adapted to apply a clamping force toward the first die head 320 to the second die head 330. In some application examples, the elastic preload assembly 360 includes a first fastening rod 361, a first sliding member 363, and a first elastic member 364. Both the first die head 320 and the second die head 330 are provided with a first clearance extending in the relative displacement direction. The first sliding member 363 is slidably mounted on the second die head 330. The first fastening rod 361 passes through the first clearance and the first sliding member 363, and the end of the first fastening rod 361 is provided with a limiting part 362. The first elastic member 364 is sleeved on the first fastening rod 361, and its two ends abut against the limiting part 362 and the first sliding member 363, respectively. The limiting part 362 and the first slider cooperate to limit the elastic element on the first fastening rod 361. The limiting part 362 can be an external component such as a washer 350, a pin, or a nut, or it can be a protrusion provided on the first fastening rod 361. The first elastic element 364 is adapted to apply an elastic preload to the first sliding element 363, thereby making the second mold head 330 and the first mold head 320 fit tightly together. The contact surfaces between the first sliding element 363 and the second mold head 330 are both smooth surfaces to reduce sliding friction and make the sliding of the second mold head 330 smoother. In some other application examples, the elastic preload assembly 360 is a disc spring bolt.

[0053] Please refer to Figure 4 This embodiment also provides a coating control method applied to the above-mentioned coating equipment, including steps S100 to S400. It should be noted that the numbering of the steps in this embodiment is only for ease of review and understanding, and not to limit the execution order of the steps. The details of each step are described below: S100. During the coating process of the current collector 10, the current collector 10 is subjected to scratch defect detection by the scratch defect detection component 200 to obtain the first detection result; For example, during the coating process of the current collector 10, the timing of the appearance of obstructions 20 in the slurry is usually uncertain. When obstructions 20 appear, they cause white streaks on the surface of the current collector 10. Existing technologies usually involve manual inspection during production or visual inspection of the semi-finished product after coating. However, these inspection methods are often slow and can easily waste a lot of material. This embodiment uses a scratch defect detection component 200 to detect scratch defects in the current collector 10. This allows for real-time monitoring of scratch defects on the surface of the current collector 10, thereby promptly detecting whether obstructions 20 flow out with the slurry and become stuck in the coating gap 323 between the lip of the coating die 300 and the coating roller 100.

[0054] S200, if the first detection result indicates the presence of scratch defects, the second die head 330 is moved a preset distance away from the coating roller 100 relative to the first die head 320 by the first drive mechanism 340; For example, in related technologies, even if scratches are found on the surface of the current collector 10 during production inspections, the structure of the coating die 300—namely, the fixed connection between the first die 320 and the second die 330—means that the shape of the end lip of the feed gap 322 cannot be dynamically adjusted. Therefore, when an obstruction 20 at the lip causes scratches on the surface of the current collector 10, the usual approach is to manually clean the lip area after stopping the machine to remove the obstruction 20. This method not only interrupts the normal coating production process, severely impacting production continuity, but also generates significant material waste during shutdown and restart. Furthermore, manual cleaning is inefficient and cannot meet the demands of high-speed, continuous production.

[0055] In this embodiment, the second die head 330 is configured to move relative to the first die head 320 along a preset straight line. The first drive mechanism 340 is connected to the second die head 330 and is used to drive the second die head 330 to adjust its displacement relative to the first die head 320. When the scratch defect detection component 200 detects a scratch defect on the surface of the current collector 10, the first drive mechanism 340 drives the second die head 330 to move away from the coating roller 100. On the one hand, the movement of the second die head 330 increases the coating gap 323 between the second die head 330 and the coating roller 100, reducing the pressure of the coating die head 300 on the surface of the current collector 10 and preventing the scratch defect from being further deepened or expanded due to the continuous scraping of the current collector 10 by the obstruction 20. On the other hand, the movement of the second die head 330 increases the exposed area of ​​the top of the first die head 320, thereby forming a larger clearance space in the lip area.

[0056] During the above process, the coating operation continues, and the slurry flows continuously from the slurry channel 321 through the feeding gap 322 to the lip region under the action of the feeding pressure. As the clearance space in the lip region increases, the flow velocity and flow rate distribution of the slurry in this region change, and the scouring force exerted by the gushing slurry on the stuck object 20 increases accordingly. Under the action of the scouring force of the slurry and the flow of the current collector 10, the stuck object 20 can be smoothly flushed away from the lip region from the increased clearance space, thereby realizing the online automatic removal of the stuck object 20.

[0057] S300, The current collector 10 is subjected to scratch defect detection by the scratch defect detection component 200 to obtain a second detection result; For example, during the process of removing the obstruction 20 by the coating die 300, the scratch defect detection component 200 continuously performs real-time online detection on the surface of the current collector 10 to dynamically track the healing process of the scratch defect. Specifically, during the process of the second die 330 moving relative to the first die 320 and the lip area increasing the clearance space to remove the obstruction 20, the scratch defect detection component 200 continuously collects coating state information on the surface of the current collector 10 to determine the removal status of the obstruction 20. When the obstruction 20 is detected to be removed, the second die 330 is promptly driven to reset to the normal mating position with the first die 320 via the first drive mechanism 340, so that the feeding gap 322 and the lip structure return to standard working conditions. Thus, the entire discharge cycle from the detection and removal of the obstruction 20 to the reset of the second die head 330 can be controlled within the range of milliseconds to seconds. This helps to shorten the discharge time and effectively limit the duration of changes in the lip structure morphology, minimizing the time window for deviations in the lip structure morphology and slurry flow field distribution from standard operating conditions. This minimizes the impact on the uniformity of the coating thickness, achieving automatic online removal of the obstruction 20 while maximizing the stability of the coating process and the consistency of coating quality. Even if a very short area of ​​slight coating thickness fluctuation remains on the surface of the current collector 10, it can be eliminated through subsequent rolling or trimming.

[0058] S400, if the second test result indicates that there is no scratch defect, the second mold head 330 is reset by the first drive mechanism 340.

[0059] For example, when the scratch defect detection component 200 does not detect scratch defects on the surface of the current collector 10, the first drive mechanism 340 drives the second die head 330 to reset, so that the second die head 330 returns to the normal mating position with the first die head 320, the coating gap 323 and the material feeding gap 322 return to the standard working condition, and the coating process automatically returns to the normal state.

[0060] Through the above methods, this embodiment can promptly detect scratches on the surface of the current collector 10 without shutting down the machine, and automatically remove the lip obstruction 20 that causes the scratches, achieving online detection and online self-healing control of scratches. Compared with related technologies that rely on manual cleaning during machine shutdown, this embodiment effectively ensures the continuity of coating production, improves equipment uptime, significantly reduces material waste caused by downtime and defective products, and avoids the efficiency bottleneck caused by manual cleaning, which is conducive to reducing production costs and improving product yield.

[0061] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A coating apparatus suitable for coating a current collector (10), characterized in that, include: A coating roller (100) is adapted to connect to the current collector (10). A scratch defect detection component (200) is located on the adjacent side of the coating roller (100), with the detection end of the scratch defect detection component (200) facing the current collector (10). The coating die (300) is provided with a base (310), a first die (320), a second die (330), and a first drive mechanism (340). The first die (320) is mounted on the base (310) and has a slurry channel (321) inside. The second die (330) is located above the first die (320). A feeding gap (322) communicating with the slurry channel (321) is provided between the second die (330) and the first die (320). The end of the feeding gap (322) is provided with a lip. A coating gap (323) is provided between the lip and the coating roller (100). The first drive mechanism (340) is connected to the second die (330) and is used to drive the second die (330) to move relative to the first die (320) along the extension direction of the feeding gap (322) to increase the coating gap (323).

2. The coating equipment according to claim 1, characterized in that, The first mold head (320) and the second mold head (330) are provided with a first track-type guide and are slidably connected through the first track-type guide; Alternatively, a support member is provided on the base (310), and the support member and the second mold head (330) are provided with a second track-type guide, and are slidably connected through the second track-type guide.

3. The coating equipment according to claim 1, characterized in that, The bottom of the second mold head (330) is provided with a gasket (350), and is connected to the first mold head (320) through the gasket (350). Both the surface of the gasket (350) and the surface of the first mold head (320) are provided with a wear-resistant coating.

4. The coating equipment according to claim 1, 2 or 3, characterized in that, The second die head (330) is connected to an elastic preload assembly (360), which is adapted to apply a clamping force toward the first die head (320) to the second die head (330).

5. The coating equipment according to claim 4, characterized in that, The elastic preload assembly (360) includes a first fastening rod (361), a first sliding member (363), and a first elastic member (364). The first die head (320) and the second die head (330) are both provided with a first clearance extending along the relative displacement direction. The first sliding member (363) is slidably mounted on the second die head (330). The first fastening rod (361) passes through the first clearance and the first sliding member (363), and the end of the first fastening rod (361) is provided with a limiting part (362). The first elastic member (364) is sleeved on the first fastening rod (361), and its two ends abut against the limiting part (362) and the first sliding member (363) respectively.

6. The coating equipment according to claim 1, characterized in that, The coating equipment also includes a displacement sensor located adjacent to the lip and adapted to detect the movement distance of the second die head (330).

7. The coating equipment according to claim 1 or 6, characterized in that, The second mold head (330) moves a distance of [1, 50] micrometers relative to the first mold head (320).

8. A coating die head, characterized in that, include: Base (310); A first mold head (320) is installed on the base (310), and a slurry channel (321) is provided inside the first mold head (320). The second mold head (330) is located above the first mold head (320), and a feeding gap (322) communicating with the slurry channel (321) is provided between the second mold head (330) and the first mold head (320). A first drive mechanism (340) is connected to the second die head (330) and is used to drive the second die head (330) to move relative to the first die head (320) along the extension direction of the feed gap (322) to increase the top exposed area of ​​the first die head (320).

9. The coating die head according to claim 8, characterized in that, The second die head (330) is connected to an elastic preload assembly (360), which is adapted to apply a clamping force toward the first die head (320) to the second die head (330).

10. A coating control method, applied to the coating equipment as described in any one of claims 1 to 7, characterized in that, include: During the coating process of the current collector (10), the current collector (10) is subjected to scratch defect detection by the scratch defect detection component (200) to obtain a first detection result; If the first detection result indicates the presence of scratch defects, the second die head (330) is driven by the first drive mechanism (340) to move a preset distance relative to the first die head (320) in a direction away from the coating roller (100); The scratch defect detection component (200) is used to detect scratch defects in the current collector (10) to obtain a second detection result; If the second detection result indicates that there is no scratch defect, the second mold head (330) is reset by the first drive mechanism (340).

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