A cell top side sealing device for processing of automobile lithium batteries and a process thereof

Abstract

This invention discloses a top-side sealing device and process for automotive lithium battery processing, relating to the field of lithium battery processing technology. It includes a worktable, a hot-pressing unit mounted above the worktable, and a placement tray fixed to the worktable. It also includes a rotating folding mechanism, a follow-up straightening mechanism, and a linkage mechanism. The rotating folding mechanism includes a rotating rod rotatably mounted on the placement tray, which is rotatably connected to a pressure plate for folding aluminum-plastic film via a connecting rod. The follow-up straightening mechanism includes a slide rail fixed to the placement tray, within which a smoothing roller for smoothing the aluminum-plastic film is slidably mounted. The linkage mechanism is drive-connected between the pressure plate and the smoothing roller. This invention solves the problem in existing top-side sealing processes where the folding of the aluminum-plastic film is entirely manual, making it difficult to guarantee the parallelism and alignment accuracy of the upper and lower sealing edges. This often results in defects such as edge skewing, misalignment, and folding line deviation, leading to low cell yield.

Description

Technical Field

[0001] This invention relates to the field of lithium battery processing technology, specifically to a top-side sealing device and process for automotive lithium battery cells. Background Technology

[0002] The top-side sealing device for automotive lithium battery processing is a specialized packaging equipment designed for automotive soft-pack lithium batteries. It uses a zoned temperature-controlled hot-pressing process with upper and lower heat-sealing heads to heat-melt the inner PP layer of the aluminum-plastic film, completing the top sealing of the battery cell with tab avoidance and the sealing of the left and right sides, as well as reserving a liquid injection gas bag.

[0003] For example, a cell top-side sealing device disclosed in CN210956882U can realize the setting of a packaging linear guide rail on the packaging frame, and drive the packaging slider to move in an oriented manner along the packaging linear guide rail through the packaging power component, thereby driving the packaging mold to move in an oriented manner along the packaging linear guide rail, which can effectively improve the stability and accuracy of packaging. At the same time, the structure is simple and more convenient for users to use. However, the existing cell top-side sealing devices still have some shortcomings.

[0004] In the existing top-side sealing process for automotive lithium battery cells, the wound cell is first placed in a fixture cavity, and then the aluminum-plastic film wrapping the cell is manually folded along the fold line at the rear edge of the cavity to align the top sealing edges of the upper and lower layers of aluminum-plastic film. The fixture is then transferred to the top-side sealing equipment for heat sealing. However, most of the above process relies entirely on manual folding operations. Due to the operator's skill level, fatigue, and operational stability, problems such as aluminum-plastic film fold line misalignment, non-parallelism of the upper and lower sealing edges, and overall skewness of the sealing edges are very likely to occur, resulting in a decrease in the yield of the battery cells.

[0005] To address the aforementioned issues, there is an urgent need for innovative designs based on the existing top-side sealing devices for automotive lithium battery cells. Summary of the Invention

[0006] This invention addresses the problem of overly simplistic solutions in existing technologies by providing a significantly different approach. Specifically, the invention aims to provide a top-side sealing device and process for automotive lithium battery cells, addressing the issue that in existing top-side sealing processes, the folding of the aluminum-plastic film relies entirely on manual labor, making it difficult to guarantee the parallelism and alignment accuracy of the upper and lower sealing edges. This often results in defects such as edge skewing, misalignment, and fold line deviation, leading to low cell yield.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a top-side sealing device for automotive lithium battery processing, comprising a worktable, a hot pressing unit disposed above the worktable, and a placement tray fixed on the worktable, and further comprising a rotation folding mechanism, a follow-up wire straightening mechanism, and a linkage mechanism. The rotating folding mechanism includes a rotating rod rotatably mounted on a placement tray, and the rotating rod is rotatably connected to a pressure plate for folding aluminum-plastic film via a connecting rod; The follow-up straightening mechanism includes a slide rail fixed on the placement tray, and a wiping roller for smoothing the aluminum-plastic film is slidably arranged inside the slide rail; The linkage mechanism is connected between the pressure plate and the wiping roller, so that as the pressure plate rotates from an inclined state to a horizontal state, the wiping roller moves synchronously along the slide rail from the fold line of the aluminum-plastic film to the sealing direction to complete the initial lining and air release.

[0008] Preferably, a telescopic rod is provided through the rotating rod, a pressing member is rotatably provided between the rotating rods, a driven guide rail is fixed at the top of the pressing member, and the end of the telescopic rod is slidably provided in the driven guide rail.

[0009] Preferably, the linkage mechanism includes a first link, a second link, a connecting rod, and a third link.

[0010] Preferably, a connecting block is fitted onto one end of the wiping roller, and the connecting block is rotatably connected to one end of the first connecting rod.

[0011] Preferably, the other end of the first link is rotatably connected to one end of the third link, and the middle part of the third link is rotatably mounted on the mounting rod of the placement plate.

[0012] Preferably, the other end of the third link is rotatably connected to one end of the connecting rod, and the other end of the connecting rod is slidably disposed within the second link.

[0013] Preferably, one end of the second connecting rod is fixedly connected to one side of the pressure plate.

[0014] Preferably, the placement tray is provided with symmetrically distributed connectors, and the rotating rod is rotatably connected to the connectors.

[0015] Preferably, the placement tray is provided with rotating blocks distributed at equal angles, and the bottom of the rotating blocks has an opening for inserting aluminum-plastic film for sealing the edge.

[0016] A top-side sealing process for automotive lithium battery cells includes the following steps: S1. Loading and positioning: Place the wound battery cell in the positioning slot of the placement tray, fully unfold the aluminum-plastic film, align the upper and lower sealing edges of the aluminum-plastic film and insert it into the opening of the rotating block, rotate the rotating rod to make the pressure plate tilted, and its tip close to the fold of the aluminum-plastic film. S2. Automatic folding and straightening: The telescopic rod extends and drives the lower pressure component to rotate through the driven guide rail, causing the pressure plate to rotate around the end of the connecting rod as the axis and gradually flatten it; at the same time, the pressure plate drives the wiping roller to move along the slide rail from the fold line to the sealing direction through the linkage mechanism, and performs preliminary straightening and air removal on the aluminum-plastic film. S3. Hot-press sealing: After the pressure plate completely flattens the aluminum-plastic film, the rotating block rotates to expose the top edge sealing. The hot-pressing unit presses down to complete the hot-press sealing. Then, each mechanism resets and the battery cell is removed.

[0017] Compared with the prior art, the beneficial effects of the present invention are: After manually aligning the upper and lower edges of the aluminum-plastic film, it is inserted into the opening of the rotating stop. The rotating stop automatically clamps the edge for precise positioning. Then, the rotating rod is rotated to tilt the pressure plate, with its tip pressed against the folded part of the aluminum-plastic film. Next, the telescopic rod extends, driving the lower pressure component to rotate via the driven guide rail. This causes the pressure plate to slowly rotate from the tilted state to the horizontal state around the end of the connecting rod, flipping the flat aluminum-plastic film upwards to cover the surface of the battery cell, completing the folding action. This invention achieves 100% synchronization between the folding and straightening actions, completely replacing the traditional manual folding process. The edge alignment accuracy is improved from ±0.5mm to ±0.05mm, completely solving the problems of edge skewing, misalignment, and fold line deviation caused by the influence of manual operation skill and fatigue. On the one hand, the product defect rate has been reduced from 3%-5% to below 0.1%. On the other hand, the ideal process sequence of "folding and smoothing the lines at the same time, smoothing the lines first and then flattening" has been achieved. The wiping roller gradually rolls from the fold line to the sealing edge, which can drive out all the air in the aluminum-plastic film interlayer. This avoids the problem of air not being able to be discharged and the appearance of bubbles and wrinkles after heat sealing caused by the traditional "flattening first and then smoothing the lines". In addition, the process of smoothing the lines first and then flattening can make the upper and lower aluminum-plastic films completely adhered, and the sealing edge thickness is uniform after heat sealing, which significantly improves the sealing performance and service life of the battery cell. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the top-side sealing device for the lithium battery cell of the present invention.

[0019] Figure 2 This is a schematic diagram of the internal structure of the top-side sealing device for lithium battery cells of the present invention.

[0020] Figure 3 This is a schematic diagram of the placement tray structure of the top-side sealing device for lithium battery cells according to the present invention.

[0021] Figure 4 This is a schematic diagram of the pressing assembly for placing the disc in this invention.

[0022] Figure 5 This is a schematic diagram of the initial pressing state of the pressing assembly for placing the disc in this invention.

[0023] Figure 6 This is a schematic diagram of the pressing state of the pressing component for placing the disc in this invention.

[0024] Figure 7 This is a magnified schematic diagram showing the details of the pressing component of the present invention.

[0025] Figure 8 This is a magnified schematic diagram showing the pressing state of the pressing component of the present invention.

[0026] In the diagram: 1. Workbench; 2. Hot pressing unit; 3. Placement tray; 4. Rotating stop; 5. Connecting component; 6. Rotating rod; 601. Connecting rod; 7. Pressure plate; 8. Telescopic rod; 9. Slide rail; 10. Wiping roller; 11. Lower pressing component; 1101. Driven guide rail; 12. First connecting rod; 13. Second connecting rod; 14. Connecting rod; 15. Third connecting rod; 16. Connecting block. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] Please see Figures 1 to 8 The present invention provides a technical solution: a top-side sealing device for automotive lithium battery processing, including a worktable 1, a hot pressing unit 2 disposed above the worktable 1 and a placement tray 3 fixed on the worktable 1, and also includes a rotation folding mechanism, a follow-up wire straightening mechanism and a linkage mechanism. The rotating folding mechanism includes a rotating rod 6 rotatably mounted on the placement tray 3, and the rotating rod 6 is rotatably connected to a pressure plate 7 for folding aluminum-plastic film via a connecting rod 601; The follow-up line straightening mechanism includes a slide rail 9 fixed on the placement tray 3, and a wiping roller 10 for smoothing the aluminum-plastic film is slidably arranged in the slide rail 9; The linkage mechanism is connected between the pressure plate 7 and the wiping roller 10, so that as the pressure plate 7 rotates from an inclined state to a horizontal state, the wiping roller 10 moves synchronously along the slide rail 9 from the fold line of the aluminum-plastic film to the sealing direction to complete the initial lining and air removal.

[0029] In this embodiment, a rectangular positioning groove matching the shape of the battery cell is provided on the placement tray 3. The depth of the positioning groove is 1 / 2 of the thickness of the battery cell, and the roughness of the groove wall Ra≤1.6μm. The rotation folding mechanism, the follow-up winding mechanism and the linkage mechanism are all integrated and installed on the same side of the placement tray 3 to form an independent folding station module.

[0030] A telescopic rod 8 is provided through the rotating rod 6, and a pressing member 11 is rotatably provided between the rotating rods 6. A driven guide rail 1101 is fixed to the top of the pressing member 11, and the end of the telescopic rod 8 is slidably provided in the driven guide rail 1101.

[0031] In this embodiment, a through hole is machined in the middle of the rotating rod 6. The cylinder of the telescopic rod 8 passes through the through hole and is fixedly connected to the rotating rod 6 via a flange. The piston rod of the telescopic rod 8 extends towards the pressure plate 7. The corner of the lower pressure member 11 is hinged to the rotating rod 6 via a pin and can rotate ±45° around the rotating rod 6. The driven guide rail 1101 is welded to the top of the lower pressure member 11, and the groove width is 0.2mm larger than the diameter of the roller at the end of the piston rod of the telescopic rod 8. When the telescopic rod 8 extends, the roller at the end of the piston rod rolls in the driven guide rail 1101, pushing the lower pressure member 11 to rotate clockwise around the rotating rod 6, and its lower end presses down on the rear end of the pressure plate 7.

[0032] The linkage mechanism includes a first link 12, a second link 13, a connecting link 14, and a third link 15.

[0033] In this embodiment, the linkage mechanism is a planar four-bar linkage, installed on the side of the placement tray 3, located below the pressure plate 7. Its function is to convert the small-angle rotational motion of the pressure plate 7 around the pin shaft into the large-stroke linear motion of the wiping roller 10 along the slide rail 9. The transmission ratio is designed to be 3:1, that is, when the pressure plate 7 rotates 30°, the wiping roller 10 can slide 150mm along the slide rail 9, covering the entire edge sealing length.

[0034] One end of the wiping roller 10 is fitted with a connecting block 16, which is rotatably connected to one end of the first connecting rod 12.

[0035] In this embodiment, a deep groove ball bearing is installed at each end of the wiping roller 10, and the connecting block 16 is fitted on the outer ring of the bearing, so that the wiping roller 10 can rotate freely. The bottom of the connecting block 16 is machined with a groove that matches the slide rail 9.

[0036] The other end of the first link 12 is rotatably connected to one end of the third link 15, and the middle part of the third link 15 is rotatably mounted on the mounting rod of the placement plate 3.

[0037] In this embodiment, one end of the first connecting rod 12 is hinged to the lower end of the third connecting rod 15 via a pin, and the other end is hinged to the connecting block 16 via a pin. When the third connecting rod 15 rotates clockwise, its lower end moves to the left, and the first connecting rod 12 pulls the connecting block 16 to the left. The mounting rod is a cylindrical pin welded to the side of the placement plate 3. The third connecting rod 15 has a through hole in the middle, and it is fitted onto the mounting rod through the through hole, allowing it to rotate freely around the mounting rod. The third connecting rod 15 is an equal-arm lever, with both ends equidistant from the center of the mounting rod.

[0038] The other end of the third link 15 is rotatably connected to one end of the connecting rod 14, and the other end of the connecting rod 14 is slidably disposed within the second link 13.

[0039] In this embodiment, the connecting rod 14 and the second connecting rod 13 are connected by a sliding connection instead of a hinge. The end of the second connecting rod 13 moves in an arc with a radius of 30mm centered on the hinge point of the pressure plate 7, while the end of the third connecting rod 15 moves in an arc with a radius of 50mm centered on the mounting rod. The centers and radii of the two arcs are different, and their movement trajectories do not coincide. If they were directly hinged, the displacement difference between the two arc movements would generate huge internal stress, causing the mechanism to jam or even the connecting rod to break. The sliding connection can fully adapt to this displacement difference. The connecting rod 14 slides freely in the waist-shaped groove of the second connecting rod 13, transmitting force without restricting relative displacement, thus ensuring smooth operation of the mechanism.

[0040] One end of the second connecting rod 13 is fixedly connected to one side of the pressure plate 7.

[0041] In this embodiment, the second connecting rod 13 adopts an L-shaped structure instead of a straight structure in order to change the direction of force transmission: the rotational motion of the pressure plate 7 is a downward rotation around the pin shaft at the end of the connecting rod 601, and its side motion trajectory is a downward arc. If a straight connecting rod is used, the direction of force transmission is upward, which will cause the third connecting rod 15 to rotate counterclockwise and the wiping roller 10 to move in the wrong direction. The 90° included angle of the L-shaped connecting rod can convert the downward force into a rightward force, pushing the third connecting rod 15 to rotate clockwise, so that the wiping roller 10 moves in the correct sealing direction.

[0042] The placement plate 3 is provided with symmetrically distributed connectors 5, and the rotating rod 6 is rotatably connected to the connectors 5.

[0043] In this embodiment, the upper part of the connector 5 is provided with a bearing hole, and a bearing is press-fitted into the hole. The two ends of the rotating rod 6 are respectively interference-fitted into the inner rings of the two bearings, so that the rotating rod 6 can rotate freely around its own axis.

[0044] The placement tray 3 is provided with rotating blocks 4 distributed at equal angles, and the bottom of the rotating blocks 4 has an opening for inserting aluminum-plastic film for sealing the edge.

[0045] In this embodiment, four rotating blocks 4 are provided, located at the four corners of the placement tray 3. Each rotating block 4 rotates 90°. When the upper and lower sealing edges of the aluminum-plastic film are aligned and inserted into the opening, the two side walls of the opening clamp the sealing edges.

[0046] A top-side sealing process for automotive lithium battery cells includes the following steps: S1. Loading and positioning: Place the wound battery cell in the positioning slot of the placement tray 3, fully unfold the aluminum-plastic film, align the upper and lower sealing edges of the aluminum-plastic film and insert it into the opening of the rotating block 4, rotate the rotating rod 6 to make the pressure plate 7 tilted, and its tip close to the fold of the aluminum-plastic film. S2. Automatic folding and straightening: The telescopic rod 8 extends and drives the lower pressing component 11 to rotate through the driven guide rail 1101, causing the pressure plate 7 to rotate around the end of the connecting rod 601 as the axis and gradually flatten it; at the same time, the pressure plate 7 drives the wiping roller 10 to move along the slide rail 9 from the folding line to the sealing direction through the linkage mechanism, and performs preliminary straightening and air removal on the aluminum-plastic film. S3. Hot pressing edge sealing: After the pressure plate 7 completely flattens the aluminum-plastic film, the rotating block 4 rotates to expose the top edge sealing. The hot pressing unit 2 presses down to complete the hot pressing sealing. Then, each mechanism resets and the battery cell is removed.

[0047] Working principle: When using this battery cell top and side sealing device for automotive lithium battery processing, firstly, manually align the top and right sides of the upper and lower layers of aluminum-plastic film and insert them into the openings at the bottom of the corresponding rotating block 4. Rotate the block 4 to clamp and position the sealing edge. Then rotate the rotating rod 6. The rotating rod 6 drives the pressure plate 7 to swing downward through the connecting rod 601, so that the pressure plate 7 is tilted at 30° and its tip is just close to the fold line of the aluminum-plastic film. The equipment is then started. The piston rod of the telescopic rod 8 extends, and the nylon roller at its end enters the waist-shaped groove of the driven guide rail 1101 and rolls, pushing the lower pressing member 11 to rotate clockwise around the rotating rod 6. The lower end of the lower pressing member 11 presses down on the rear end of the pressure plate 7, causing the pressure plate 7 to rotate counterclockwise around the pin at the end of the connecting rod 601. It slowly rotates from a 30° tilted state to a horizontal state, flipping up the aluminum-plastic film that is laid flat on the right half of the placement tray 3 and covering the upper surface of the battery cell. While the pressure plate 7 rotates counterclockwise, the second connecting rod 13 fixed on its side moves downward in an arc. The inner wall of the waist-shaped groove of the second connecting rod 13 pushes the connecting rod 14 downward, and the connecting rod 14 drives the third connecting rod 15 to rotate clockwise around the mounting rod. The lower end of the third link 15 swings to the left, pulling the connecting block 16 along the slide rail 9 to the left via the first link 12. The connecting block 16 drives the wiping roller 10 to roll forward from the rightmost fold line position of the slide rail 9 to the leftmost sealing position. During the rolling process, the surface of the wiping roller 10 is in close contact with the upper surface of the folded aluminum-plastic film, and gradually presses it from the fold line to the sealing direction, driving out all the air remaining in the aluminum-plastic film interlayer, and pressing out a straight and clear center fold line, so that the upper and lower aluminum-plastic films are completely bonded, without wrinkles or bubbles. When the telescopic rod 8 is fully extended, the pressure plate 7 rotates to a completely horizontal state, pressing the folded aluminum-plastic film tightly flat on the upper surface of the battery cell. At this time, the wiping roller 10 also slides to the leftmost end of the slide rail 9, completing the wiping and air venting work of the entire sealing area. Then, the four rotating blocks 4 rotate outward by 90°, completely exposing the sealing of the top and right sides. The hot pressing unit 2 then moves downward to start the hot pressing sealing work. Finally, the telescopic rod 8 retracts, causing the lower pressing part 11 to rotate counterclockwise. The pressure plate 7 rotates clockwise around the pin under its own gravity, returning to the 30° tilt state. At the same time, the linkage mechanism moves in the opposite direction, causing the wiping roller 10 to slide to the right along the slide rail 9, returning to the initial position. The rotating stop 4 also rotates inward 90° to reset. The battery cell with the top side seal completed can then be taken out and enter the next production cycle.

[0048] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A cell top-side sealing device for automotive lithium battery processing, comprising a worktable (1), a hot pressing unit (2) disposed above the worktable (1), and a placement tray (3) fixed on the worktable (1), characterized in that: It also includes a rotary folding mechanism, a follow-up winding mechanism, and a linkage mechanism; The rotating folding mechanism includes a rotating rod (6) rotatably mounted on the placement plate (3), and the rotating rod (6) is rotatably connected to a pressure plate (7) for folding aluminum-plastic film via a connecting rod (601). The follow-up straightening mechanism includes a slide rail (9) fixed on the placement tray (3), and a wiping roller (10) for smoothing the aluminum-plastic film is slidably arranged in the slide rail (9). The linkage mechanism is connected between the pressure plate (7) and the wiping roller (10), so that during the process of the pressure plate (7) rotating from the inclined state to the horizontal state, the wiping roller (10) moves synchronously along the slide rail (9) from the fold line of the aluminum-plastic film to the sealing direction to complete the initial wiping and air release.

2. The cell top-side sealing device for automotive lithium battery processing according to claim 1, characterized in that: A telescopic rod (8) is provided through the rotating rod (6), and a pressing member (11) is rotatably provided between the rotating rods (6). A driven guide rail (1101) is fixed on the top of the pressing member (11), and the end of the telescopic rod (8) is slidably provided in the driven guide rail (1101).

3. The cell top-side sealing device for automotive lithium battery processing according to claim 1, characterized in that: The linkage mechanism includes a first link (12), a second link (13), a connecting rod (14), and a third link (15).

4. The cell top-side sealing device for automotive lithium battery processing according to claim 3, characterized in that: One end of the wiping roller (10) is fitted with a connecting block (16), and the connecting block (16) is rotatably connected to one end of the first connecting rod (12).

5. The cell top-side sealing device for automotive lithium battery processing according to claim 4, characterized in that: The other end of the first link (12) is rotatably connected to one end of the third link (15), and the middle part of the third link (15) is rotatably mounted on the mounting rod of the placement plate (3).

6. The cell top-side sealing device for automotive lithium battery processing according to claim 5, characterized in that: The other end of the third link (15) is rotatably connected to one end of the connecting rod (14), and the other end of the connecting rod (14) is slidably disposed within the second link (13).

7. The cell top-side sealing device for automotive lithium battery processing according to claim 6, characterized in that: One end of the second connecting rod (13) is fixedly connected to one side of the pressure plate (7).

8. The cell top-side sealing device for automotive lithium battery processing according to claim 1, characterized in that: The placement tray (3) is provided with symmetrically distributed connectors (5), and the rotating rod (6) is rotatably connected to the connectors (5).

9. The cell top-side sealing device for automotive lithium battery processing according to claim 1, characterized in that: The placement tray (3) is provided with rotating blocks (4) distributed at equal angles, and the bottom of the rotating blocks (4) is provided with an opening for inserting aluminum-plastic film for sealing.

10. A top-side sealing process for automotive lithium battery cells, applicable to the top-side sealing device for automotive lithium battery cells as described in any one of claims 1-9, characterized in that, Includes the following steps: S1. Loading and positioning: Place the wound battery cell in the positioning slot of the placement tray (3), fully unfold the aluminum-plastic film, align the upper and lower sealing edges of the aluminum-plastic film and insert it into the opening of the rotating block (4), rotate the rotating rod (6) to make the pressure plate (7) tilted, and its tip close to the fold of the aluminum-plastic film. S2, Automatic Folding and Straightening: The telescopic rod (8) extends and drives the lower pressing part (11) to rotate through the driven guide rail (1101), causing the pressure plate (7) to rotate around the end of the connecting rod (601) as the axis and gradually flatten it; at the same time, the pressure plate (7) drives the wiping roller (10) to move along the slide rail (9) from the fold line to the sealing direction through the linkage mechanism, and performs preliminary straightening and air removal on the aluminum-plastic film; S3, hot pressing edge sealing: After the pressure plate (7) completely flattens the aluminum-plastic film, rotate the stop block (4) to expose the top edge sealing. The hot pressing unit (2) presses down to complete the hot pressing sealing. Then, each mechanism resets and the battery cell is taken out.

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