A lithium battery separator coating head

Abstract

The present application relates to a kind of lithium battery separator coating machine heads, including support, gravure roll, back roll, material baffle and material box assembly;The material baffle is block, and two arc grooves are arranged in the lower end, and the upper end is connected with the moving positioning mechanism arranged on the crossbeam, so that it is located above the gravure roll and back roll, and can move in horizontal and vertical direction;The shape of the groove is adapted to the shape of the outer surface of the gravure roll and back roll, so that it can be close to the gravure roll and back roll;The material baffle is two, and is located at the two ends of the gravure roll and back roll, can be shielded to prevent material from being thrown;The material box assembly includes two material boxes, which are connected back to back in parallel by a connecting plate, and a rotating shaft is arranged on the connecting plate;The rotating shaft is connected with the material box driving motor, so that the material box assembly is rotated under the driving of the material box driving motor, realizes the alternate use of two material boxes, meets the demand of replacing scraper without stopping.

Description

Technical Field

[0001] This invention relates to the field of lithium battery separator production, and in particular to a coating production apparatus for lithium battery separators, specifically a lithium battery separator coating head. Background Technology

[0002] Currently, gravure coating is widely used in lithium battery separator coating production due to its advantages of good coating uniformity and high speed. Existing coating heads typically include a gravure roller, a back roller, a coating hopper, and a doctor blade assembly mounted on the hopper. The separator or electrode substrate passes between the gravure roller and the back roller, and the slurry in the hopper is evenly coated onto the substrate surface by the doctor blade.

[0003] However, existing coating heads have the following technical problems in actual production: Firstly, the coating width switching relies on manual operation, which is inefficient and lacks precision. When dealing with different specifications of separator width, the position of the baffles on both sides of the die head needs to be manually adjusted. This adjustment method is not only time-consuming, resulting in a shortened effective working time of the equipment, but also the positioning accuracy depends entirely on the operator's experience. This can easily lead to uneven coating edges or slurry waste due to positioning deviations, making it difficult to meet the high precision and rapid changeover requirements of modern lithium battery production.

[0004] Secondly, the problem of material spillage from both sides of the roller system is severe during high-speed operation. As lithium battery production lines develop towards higher speeds, the centrifugal force generated by the high-speed rotation of the gravure rollers easily throws the slurry off from both sides of the roller system. Existing baffles and roller surfaces are mostly fitted with clearance or simple mechanical clamping, resulting in poor sealing under high-speed conditions, leading to slurry splashing and accumulation. This not only causes material loss and pollutes the equipment environment, but also easily leads to quality defects such as uneven coating thickness and uneven electrode edges, severely restricting the improvement of production efficiency.

[0005] Third, doctor blade replacement requires machine shutdown, leading to production line interruptions. Since existing coating heads typically only have a single coating cartridge, and the doctor blade, being a consumable part, needs replacement after a period of use, each replacement necessitates stopping the coating machine. After the replacement, a trial coating and parameter adjustments must be performed again. This shutdown-based doctor blade replacement method significantly increases non-productive time, especially for highly continuous and automated production lines, where frequent start-ups and shutdowns severely impact the overall equipment efficiency (OEE).

[0006] Therefore, improvements are urgently needed to better meet production demands. Summary of the Invention

[0007] The purpose of this invention is to address the shortcomings of existing technologies by providing a lithium battery separator coating head that can automatically adapt the baffle to changes in separator width and effectively prevent material spillage. Simultaneously, it allows for non-stop switching of the scraper, creating favorable conditions for improving the automation level and production yield of the lithium battery coating process.

[0008] The technical solution of this invention is: A lithium battery separator coating head includes a support, a gravure roller, and a back roller. The support is stepped and includes two side plates and a crossbeam between the side plates. The gravure roller and the back roller are mounted side by side on the lower step of the support. The crossbeam is located above the gravure roller and the back roller. The head also includes a baffle plate and a material box assembly. The baffle plate is block-shaped, with two arc-shaped grooves on its lower edge. Its upper end is connected to a movable positioning mechanism on the crossbeam, positioning it above the gravure roller and the back roller, and allowing it to move horizontally and vertically. The shape of the grooves is adapted to the shape of the outer circumference of the gravure roller and the back roller, allowing them to fit snugly against the gravure roller and the back roller. There are two baffle plates, located at the two ends of the gravure roller and the back roller respectively, which can block and prevent material from being thrown out. The material box assembly includes two material boxes, which are connected back-to-back in parallel by a connecting plate and are respectively connected to the hopper through a conveying pipe. There are two connecting plates, which are respectively located at both ends of the material boxes. A rotating shaft is provided on the connecting plate. The rotating shaft is connected to the material box drive motor so that the material box assembly can rotate radially along the rotating shaft under the drive of the material box drive motor, so as to realize the alternating use of the two material boxes.

[0009] Furthermore, it also includes two sets of material box positioning cylinders, which are respectively set on the side plates on both sides. The end of the push rod is movably connected to the rotating shaft so as to push the material box assembly to move backward toward the gravure roller.

[0010] Furthermore, the moving positioning structure includes a horizontal moving cylinder and a vertical moving cylinder; the horizontal moving cylinder is horizontally disposed on the crossbeam, and the end of its push rod is connected to the vertical moving cylinder; the push rod of the vertical moving cylinder points downward, and its end is connected to the baffle plate.

[0011] Furthermore, both of the material boxes are vertically arranged groove-shaped structures, with a feed port and an overflow port at their upper and lower ends, respectively. A first scraper and a second scraper are provided on their front side. The first scraper and the second scraper are of the same length and are equivalent to the length of the material box, and are arranged parallel to each other along the length direction of the material box. The first scraper is adjacent to the feed port, and the second scraper is adjacent to the overflow port.

[0012] Furthermore, the feed port is located in the middle of the material box; there are two overflow ports, located at the two ends of the material box respectively.

[0013] Furthermore, the two material boxes are arranged symmetrically along the axis of the rotation shaft.

[0014] Furthermore, it also includes a scraper cover plate, which is long and narrow, with a length similar to that of the first and second scrapers. It presses on the first and second scrapers and is connected to the material box by screws passing through the scraper cover plate, thereby fixing the first and second scrapers on the material box.

[0015] Furthermore, a feeding buffer is provided on the back side of the material box; the feeding buffer is rectangular and has a feeding port; the feeding port is connected to the conveying pipe.

[0016] Furthermore, it also includes a back roller drive cylinder, which is located inside the side plate, with the end of its push rod connected to the bearing seat at the end of the back roller so as to push the back roller to move horizontally.

[0017] Furthermore, it also includes a controller, which is electrically connected to the horizontal moving cylinder, the vertical moving cylinder, the material box drive motor, the material box positioning cylinder, the gravure roller drive motor, and the back roller drive cylinder, respectively.

[0018] The beneficial effects of this invention are: 1. It adopts a fully automatic online switching system with dual material boxes, eliminating the need for disassembly and downtime for debugging, greatly improving equipment continuity; 2. The baffle plate automatically aligns left and right with the film width, eliminating the need for manual measurement and adjustment, resulting in high precision and fast changeover. 3. The baffle plate adopts an arc-shaped structure, which can effectively approach the gravure roller / back roller, and prevent the paste from being thrown to the edge of the gravure roller and back roller to the greatest extent, thus reducing the phenomenon of paste clumping and splashing onto the film surface due to the drying of the edge of the gravure roller / back roller. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the present invention.

[0020] Figure 2 yes Figure 1 A schematic diagram of the material box assembly in section A.

[0021] Among them, 1-side plate; 2-vertical moving cylinder; 3-baffle plate; 4-lateral moving cylinder; 5-adsorption roller; 6-crossbeam; 7-back roller drive cylinder; 8-gravure roller; 9-back roller; 10-feed buffer zone; 11-feed inlet; 12-connecting plate; 13-overflow port; 14-second scraper; 15-material box; 16-first scraper; 17-scraper cover plate; 18-rotating shaft; 19-material box positioning cylinder; 20-material box drive motor; 21-gravure roller drive motor; 22-adsorption roller drive motor; 23-feeding port. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0023] like Figures 1 to 2 As shown.

[0024] A lithium battery separator coating head includes a support, a gravure roller 8, a back roller 9, an adsorption roller 5, a baffle plate 3, a material box assembly, and a controller.

[0025] The support is stepped and includes two side plates 1 and a crossbeam 6 mounted between the side plates.

[0026] The gravure roller 8 and the back roller 9 are mounted side-by-side on the lower step of the bracket. The adsorption roller 5 is mounted on the upper step of the bracket. The crossbeam 6 is located above the gravure roller 8 and the back roller 9. The ends of the gravure roller 8 and the adsorption roller 5 are respectively equipped with a gravure roller drive motor 21 and an adsorption roller drive motor 22 to drive the gravure roller 8 and the adsorption roller 5 to rotate. A back roller drive cylinder 7 is also included, located inside the side plate 1, with the end of its push rod connected to the bearing seat at the end of the back roller 9 to push the back roller to move horizontally, completing the coating process.

[0027] The baffle plate 3 is block-shaped with a spindle-shaped cross-section. Its lower edge has two arc-shaped grooves, and its upper end is connected to a movable positioning mechanism mounted on the crossbeam, positioning it above the gravure roller 8 and the back roller 9. The shape of the grooves conforms to the outer circumferential surface of the gravure roller and the back roller, allowing them to fit snugly against them and prevent the slurry from being thrown out. Preferably, there are two baffle plates 3, located at both ends of the gravure roller and the back roller, respectively, to provide lateral shielding and minimize the slurry from being thrown to the edges of the gravure roller and the back roller, thus mitigating the phenomenon of slurry agglomeration and splashing onto the film surface due to drying at the edges of the gravure roller / back roller.

[0028] The moving positioning structure includes a horizontal moving cylinder 4 and a vertical moving cylinder 2. The horizontal moving cylinder 4 is horizontally mounted on the crossbeam 6, and the end of its push rod is connected to the vertical moving cylinder 2. The push rod of the vertical moving cylinder 2 points downward, and its end is connected to the baffle plate 3. Thus, through the movement of the horizontal and vertical moving cylinders, the baffle plate moves horizontally and vertically, ensuring that it meets the changes in the width of the diaphragm in the horizontal direction and fully approaches the gravure roller and back roller in the vertical direction, fully meeting the requirements for preventing material spillage. Preferably, the baffle plate 3 is made of polytetrafluoroethylene.

[0029] The material box assembly includes a material box 15, a material box drive motor 20, and a material box positioning cylinder 19, etc.

[0030] The front side of the material box 15 is a vertically arranged groove-shaped structure, with a feed port 23 and an overflow port 13 at its upper and lower ends, respectively. Its back side is flat and has a feed buffer zone 10. The feed port 23 is located in the middle of the material box 15. There are two overflow ports 13, located at opposite ends of the material box. The feed buffer zone 10 is a rectangular box-shaped structure connected to the material box 15, and has a feed port 11. This feed port 11 is connected to the hopper via a conveying pipe, so that the slurry in the hopper is conveyed to the material box after passing through the feed buffer zone, and then flows out through the feed port to coat the diaphragm on the gravure roller. Preferably, the two feed buffer zones can be made into a single unit, with the interior divided into two independent areas by a partition, each corresponding to a different material box and connected to a different feed port for production and installation.

[0031] A first scraper 16 and a second scraper 14 are provided on the front side of the material box 15. The first scraper 16 and the second scraper 14 are of the same length and are comparable to the length of the material box 15, and are arranged parallel to each other along the length direction of the material box. The first scraper 16 is adjacent to the feed port 23. The second scraper 14 is adjacent to the overflow port 13.

[0032] Furthermore, it also includes a scraper cover plate 17. There are two scraper cover plates 17, both of which are long strips with a length equivalent to that of the first scraper and the second scraper. They are respectively pressed on the first scraper and the second scraper, and are connected to the material box by screws passing through the scraper cover plate, thereby fixing the first scraper and the second scraper to the material box, which can facilitate the installation and removal of the scraper.

[0033] The material boxes consist of two identical structures, connected back-to-back in parallel via connecting plates 12. Two connecting plates 12 are respectively located at both ends of the material boxes. A rotating shaft 18 is mounted on each connecting plate 12. This rotating shaft 18 is connected to a material box drive motor 20, allowing the material box assembly to rotate radially along the rotating shaft under the drive of the motor, enabling the two material boxes to be used alternately. Furthermore, the scrapers on the material boxes can be replaced when not in use, avoiding the adverse production impact previously caused by needing to stop the machine to replace scrapers.

[0034] Two sets of material box positioning cylinders 19 are respectively disposed on the side plates 1 on both sides. The end of the push rod of the cylinder is movably connected to the rotating shaft 18 so as to push the material box assembly to move backward toward the gravure roller. This allows the material box assembly to be moved backward toward the gravure roller first when the material box needs to be replaced, thus satisfying the rotation requirements of the material box assembly. After the material box assembly has rotated, the action of the material box positioning cylinders 19 moves the material box assembly toward the gravure roller, so that the material box is against the gravure roller, satisfying the requirements of the coating operation.

[0035] The controller is a PLC (Programmable Logic Controller), which is electrically connected to the horizontal moving cylinder, vertical moving cylinder, material box drive motor, material box positioning cylinder, gravure roller drive motor, and back roller drive cylinder. By setting the corresponding formula parameters, it can realize the fully automatic online rotation and switching of material boxes, and control the baffle plate to automatically follow the film width of the diaphragm for left and right alignment.

[0036] The operation process of this invention is as follows: S1. During normal coating production, the material box positioning cylinder is in the retracted state, the back roller is in the extended and bonding working state, the horizontal movement electric cylinder of the baffle plate maintains the automatic alignment position according to the current production film width parameters, and the vertical movement cylinder of the baffle plate maintains the downward sealing state, so that the equipment can continuously and stably coat.

[0037] S2. When the system triggers a cartridge switching instruction (timed switching / slurry depletion switching / formula switching), the PLC executes the entire interlocking switching procedure: (1) First-resign interlock The PLC prioritizes the retraction and retraction of the back roller drive cylinder and the material box positioning cylinder, so that the entire coating mechanism is completely disengaged from the working bonding state, preventing the rotation switching from scratching the roller surface and damaging the equipment.

[0038] (2) Rotation of the material box assembly After all mechanisms have fully retracted and the PLC detects the retraction signal, the rotating mechanism is allowed to operate, completing the station switching of the material box assembly. The spare empty material box / new material box rotates to the working station, thereby realizing the online switching of A / B material boxes.

[0039] (3) The material box assembly is aligned, extended, and fitted. After the PLC detects the rotation into position signal, it controls the material box positioning cylinder 19 to extend and push the switched material box assembly to feed as a whole, so that the material box blade edge and the gravure roller are precisely fitted together, and the material feeding cavity is aligned and sealed.

[0040] (4) Secondary bonding and resetting of back roller After the material box is properly bonded, the signal is sent back to the PLC. The PLC outputs a command to control the back roller drive cylinder to extend again, pushing the back roller to precisely bond with the gravure roller and establish a stable pressure reference for coating the substrate.

[0041] S3. After the back rollers are fully bonded, the PLC retrieves the film width parameters for the current production formula: (1) The PLC automatically calculates the coordinates of the left and right side stop boundaries; (2) The electric cylinder that drives the baffle plate to move laterally moves automatically left and right to adaptively match the width of the base film being produced; (3) After the electric cylinder moves laterally to the position of the baffle plate, it sends a feedback signal indicating that the position is complete. (4) After the PLC detects that the position of the electric cylinder is correct, it controls the cylinder to move up and down on the baffle plate and presses it down to lock it, thus completing the protection of the left and right baffle plates.

[0042] This step mainly involves automatically adjusting the width of the baffle plate based on the width of the production film.

[0043] S4. The PLC has multiple position interlocking conditions that must be met simultaneously: - The material box positioning cylinder is properly engaged; - The back roller is properly pressed and adhered; - The electric cylinders align the left and right baffles in the lateral movement position. - The vertical movement cylinder of the baffle plate moves into place.

[0044] Only after all signals have been confirmed to be correct will the PLC unlock the coating operation permission, allowing the equipment to enter normal high-speed coating production.

[0045] Furthermore, after the material box assembly is switched, the scraper on the material box when it is not in use can be replaced. The specific steps are as follows: Use a torque wrench to unscrew the screws on the scraper cover plate by rotating them counterclockwise from the middle to both sides, and then remove the scraper cover plate and scraper. Cut scrapers to the same length as the scraper cover plate and place them under the scraper cover plate; c) Place the scraper cover plate on top and tighten the screws with a torque wrench, starting from the middle and working outwards from both sides.

[0046] Therefore, the present invention has the following advantages: 1. The dual-material box fully automatic online switching system allows for scraper replacement without downtime for debugging, greatly improving the continuity of the equipment; 2. The baffle plate automatically aligns left and right with the film width, eliminating the need for manual measurement and adjustment, resulting in high precision and fast changeover. 3. The baffle plate adopts an arc-shaped structure, which can effectively approach the gravure roller / back roller, and prevent the paste from being thrown to the edge of the gravure roller and back roller to the greatest extent, thus reducing the phenomenon of paste clumping and splashing onto the film surface due to the drying of the edge of the gravure roller / back roller.

[0047] All parts not covered in this invention are the same as or can be implemented using existing technologies.

Claims

1. A lithium battery separator coating head, comprising a support, a gravure roller, and a back roller, wherein the support is stepped and includes two side plates and a crossbeam mounted between the side plates; the gravure roller and the back roller are mounted side-by-side on the lower step of the support; the crossbeam is located above the gravure roller and the back roller, characterized in that, It also includes baffles and material box assemblies; The baffle plate is block-shaped, with two arc-shaped grooves on its lower edge. Its upper end is connected to a movable positioning mechanism on the crossbeam, positioning it above the gravure roller and the back roller, and allowing it to move horizontally and vertically. The shape of the grooves is adapted to the shape of the outer circumference of the gravure roller and the back roller, allowing them to fit snugly against the gravure roller and the back roller. There are two baffle plates, located at the two ends of the gravure roller and the back roller respectively, which can block and prevent material from being thrown out. The material box assembly includes two material boxes, which are connected back-to-back in parallel by a connecting plate and are respectively connected to the hopper through a conveying pipe. There are two connecting plates, which are respectively located at both ends of the material boxes. A rotating shaft is provided on the connecting plate. The rotating shaft is connected to the material box drive motor so that the material box assembly can rotate radially along the rotating shaft under the drive of the material box drive motor, so as to realize the alternating use of the two material boxes.

2. The lithium battery separator coating head according to claim 1, characterized in that, It also includes two sets of material box positioning cylinders, which are respectively set on the side plates on both sides. The end of the push rod is movably connected to the rotating shaft so as to push the material box assembly to move backward toward the gravure roller.

3. The lithium battery separator coating head according to claim 2, characterized in that, The moving positioning structure includes a horizontal moving cylinder and a vertical moving cylinder; the horizontal moving cylinder is horizontally mounted on the crossbeam, and the end of its push rod is connected to the vertical moving cylinder; the push rod of the vertical moving cylinder points downward, and its end is connected to the baffle plate.

4. The lithium battery separator coating head according to claim 1, characterized in that, Both material boxes are vertically arranged groove-shaped structures, with a feed port and an overflow port at their upper and lower ends, respectively. A first scraper and a second scraper are provided on their front side. The first scraper and the second scraper are of the same length and are equivalent to the length of the material box, and are arranged parallel to each other along the length of the material box. The first scraper is adjacent to the feed port, and the second scraper is adjacent to the overflow port.

5. The lithium battery separator coating head according to claim 4, characterized in that, The feed port is located in the middle of the material box; there are two overflow ports, located at the two ends of the material box respectively.

6. The lithium battery separator coating head according to claim 1, characterized in that, The two material boxes are arranged symmetrically along the axis of the rotation shaft.

7. The lithium battery separator coating head according to claim 4, characterized in that, It also includes a scraper cover plate, which is long and narrow, with a length similar to that of the first and second scrapers. It presses on the first and second scrapers and is connected to the material box by screws passing through the scraper cover plate, thereby fixing the first and second scrapers on the material box.

8. The lithium battery separator coating head according to claim 1, characterized in that, The material box has a feeding buffer zone on its back side; the feeding buffer zone is rectangular and has a feeding port on it; the feeding port is connected to the conveying pipe.

9. The lithium battery separator coating head according to claim 3, characterized in that, It also includes a back roller drive cylinder, which is located inside the side plate, and the end of its push rod is connected to the bearing seat at the end of the back roller so as to push the back roller to move horizontally.

10. The lithium battery separator coating head according to claim 9, characterized in that, It also includes a controller, which is electrically connected to the horizontal moving cylinder, the vertical moving cylinder, the material box drive motor, the material box positioning cylinder, the gravure roller drive motor, and the back roller drive cylinder, respectively.

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