Lithium battery sealing device capable of preventing aluminum plastic film from being wrinkled

Abstract

The utility model discloses a kind of lithium battery sealing equipment for preventing aluminum-plastic film wrinkle, including battery positioning module, side seal execution module and film supply module;The battery positioning module is connected with the battery clamping block of the limiting stop block and the compression driving part by two-way constraint of battery;The side seal execution module uses the hot-pressing assembly of symmetrical heating element, cooperates elastic expansion pressure plate and pressure sensor closed-loop control heat seal pressure;The film supply module is synchronous with the compression mechanism of fixed-length cutting unit and cutting knife action by linkage mechanism, and gradient micropore adsorption of negative pressure flattening unit is triggered synchronously when cutting, and negative pressure is delayed to be released.Solve the problem of aluminum-plastic film cutting deformation, conveying wrinkle and uneven hot-pressing stress, improve the flatness and air tightness of packaging.

Description

Technical Field

[0001] This utility model relates to the field of lithium battery manufacturing equipment technology, and in particular to a lithium battery sealing device that prevents aluminum-plastic film from wrinkling. Background Technology

[0002] In the side sealing (edge ​​sealing) process of pouch lithium batteries, aluminum-plastic film, as the outer casing material, needs to be heat-pressed and sealed at specific locations. Because aluminum-plastic film is thin and flexible, it is highly susceptible to wrinkles caused by external forces, uneven tension, or thermal stress during transport, cutting, positioning, and heat pressing. Wrinkles can affect the battery's appearance and dimensional consistency, or even lead to sealing failure, causing electrolyte leakage or safety hazards. Edge sealing machines are widely used in pouch lithium battery production, using heated copper strips to apply pressure to the aluminum-plastic film, fusing the inner adhesive layers together. In the lithium battery field, the thickness of the aluminum-plastic film edge sealing is particularly important for battery stability.

[0003] Traditional sealing machines, lacking a synchronous constraint mechanism, easily cause localized relaxation or curling of the film during cutting of aluminum-plastic film, forming the initial source of wrinkles. Furthermore, the cut film, during transport to the battery side, is difficult to maintain a flat state due to gravity or uneven mechanical clamping force. Thirdly, unilateral heating or rigid pressing easily leads to uneven heating and unbalanced shrinkage stress in the aluminum-plastic film, inducing wrinkles; simultaneously, unstable battery positioning exacerbates film deformation under stress. Existing equipment (such as CN110854444B) uses continuously arranged upper and lower rollers to heat and pressurize the battery air bag, simultaneously achieving heat-sealing during the transfer process. Each roller's heating temperature is relatively independent, allowing for either constant-temperature or variable-temperature heating for heat-sealing. However, the symmetry and pressure control precision of the hot-pressing module are insufficient, making it difficult to eliminate wrinkles. Therefore, a comprehensive anti-wrinkle solution that can synergistically optimize cutting control, negative pressure stabilization, and balanced hot-pressing is urgently needed. Utility Model Content

[0004] The technical problem to be solved by this utility model is to overcome the defects of the prior art and provide a lithium battery sealing device with reasonable structural design, simple operation and effective prevention of wrinkles in aluminum-plastic film during the sealing process.

[0005] To solve the above-mentioned technical problems, this utility model provides the following technical solution:

[0006] This utility model discloses a lithium battery sealing device for preventing aluminum-plastic film wrinkles, comprising a battery positioning module, a side sealing execution module, and a film supply module. The battery positioning module includes a limiting block and a pressing drive component arranged in parallel. The output end of the pressing drive component is connected to a battery clamping block. The limiting block constrains the horizontal displacement of the battery body, and the battery clamping block is driven by the pressing drive component to provide vertical clamping force. The side sealing execution module includes a horizontally movable hot-pressing assembly, which has an elastic telescopic pressure plate and heating elements symmetrically distributed on both sides. The heating working surface of the heating elements is parallel to the horizontal movement direction of the pressure plate. The film supply module includes an aluminum-plastic film conveying unit, a fixed-length cutting unit, and a negative pressure flattening unit. The pressing mechanism of the fixed-length cutting unit operates synchronously with the cutting blade. The adsorption plane of the negative pressure flattening unit is coplanar with the aluminum-plastic film conveying plane. The fixed-length cutting unit and the negative pressure flattening unit are controlled by a linkage mechanism to control their execution sequence.

[0007] As a preferred technical solution of this utility model, the clamping drive component adopts a cylinder or a servo electric cylinder, and the clamping surface of the battery clamping block is covered with an elastic buffer layer; the constraint surface of the limiting block is adapted to the shape of the side wall of the battery body.

[0008] As a preferred embodiment of this utility model, the heating element is a cylindrical heating roller with an anti-stick coating on its surface, and each heating roller is equipped with an independent temperature control module; the extension and retraction direction of the elastic telescopic pressure plate is perpendicular to the axis of the heating element.

[0009] As a preferred embodiment of this utility model, the elastic telescopic pressure plate integrates a pressure sensor, the signal output end of which is connected to the equipment control system for real-time feedback of sealing pressure and triggering of pressure compensation mechanism.

[0010] As a preferred technical solution of this utility model, the fixed-length cutting unit includes: a cutting blade with its cutting edge inclined at an acute angle along the cutting direction; a cutting blade drive component that drives the cutting blade to move vertically; and a pressing drive mechanism that includes a vertical pressing cylinder and an L-shaped pressing block hinged to the end of its piston rod. The vertical pressing cylinder is fixed to the side frame of the cutting blade, and the pressing surface of the L-shaped pressing block has anti-slip texture in the contact area with the aluminum-plastic film.

[0011] As a preferred technical solution of this utility model, the negative pressure flattening unit includes: an adsorption block with a micropore array on its top surface and connected to a negative pressure source through a vacuum pipeline; a horizontal driving mechanism that drives the adsorption block to move back and forth along a horizontal guide rail; and a height adjustment mechanism that controls the distance between the adsorption block and the aluminum-plastic film conveying plane; the distribution density of the micropore array of the adsorption block decreases from the center to the edge.

[0012] As a preferred technical solution of this utility model, the linkage mechanism includes a mechanical linkage rod group or an electronic control synchronization module, which is used to synchronously start negative pressure adsorption when the fixed-length cutting unit is pressed down, and to delay the release of negative pressure after the cutting is completed.

[0013] As a preferred technical solution of this utility model, the battery clamping block and the limiting block adopt a quick-change installation structure, and the surface of the guide roller of the aluminum-plastic film conveying unit is covered with flexible friction material.

[0014] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0015] 1. The cutting and pressing action is started simultaneously with the negative pressure adsorption. The membrane is adsorbed and fixed through the micropore array at the moment of cutting, eliminating the window period for the release of cutting stress and avoiding membrane distortion from the root. The negative pressure is released after cutting to ensure that the membrane is in a stable adsorption state throughout the transfer process, preventing wrinkles caused by gravity sagging or displacement shaking.

[0016] 2. The micropore array of the adsorption block adopts a gradient distribution with denser adsorption at the center and sparser adsorption at the edges. The strong adsorption force at the center accurately positions the membrane, while the decreasing adsorption force at the edges achieves uniform flattening over a large area, avoiding local over-adsorption deformation. The adsorption plane and the transport plane are strictly coplanar, and combined with the height adjustment mechanism, the risk of membrane bending is eliminated.

[0017] 3. The heating elements adopt symmetrically distributed cylindrical heating rollers, combined with an independent temperature control module, to achieve uniform heat field on both sides and offset the shrinkage stress on one side; the elastic telescopic pressure plate integrates a pressure sensor, which provides real-time feedback of pressure data and triggers a compensation mechanism to dynamically adjust the pressing force and avoid local overpressure that could cause the membrane surface to collapse and wrinkle. Attached Figure Description

[0018] The accompanying drawings are provided to further illustrate the present invention and form part of the specification. They are used together with the embodiments of the present invention to explain the present invention, but do not constitute a limitation thereof. In the drawings:

[0019] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0020] Figure 2 This is the front view of this utility model;

[0021] Figure 3 This is a top view of the present invention;

[0022] Figure 4 This is a cross-sectional structural schematic diagram of the present invention;

[0023] In the diagram: 1. Battery body; 2. Battery positioning module; 3. Side sealing execution module; 4. Film supply module; 21. Limiting block; 22. Pressing drive component; 23. Battery clamping block; 31. Hot pressing assembly; 41. Aluminum-plastic film conveying unit; 42. Fixed length cutting unit; 43. Negative pressure flattening unit; 311. Elastic telescopic pressure plate; 312. Heating element; 313. Pressure sensor; 421. Cutting knife; 422. Cutting knife drive component; 423. Vertical pressing cylinder; 424. L-shaped pressing block; 431. Adsorption block; 432. Horizontal drive mechanism; 433. Horizontal guide rail; 434. Height adjustment mechanism. Detailed Implementation

[0024] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0025] In the attached diagram, all identical reference numerals refer to the same components.

[0026] Example 1: As Figure 1-4 As shown, this utility model provides a lithium battery sealing device for preventing wrinkles in aluminum-plastic film, comprising:

[0027] The battery positioning module structure 2 includes limit blocks 21: symmetrically arranged on the worktable, adapted to the shape of the square battery body 1, limiting its X / Y displacement. A clamping drive component 22: a cylinder with an output force of 100 kgf, vertically mounted on the corresponding side of the limit blocks 21 via a flange. A battery clamping block 23: bolted to the end of the piston rod of the clamping drive component 22, with a 3 mm thick silicone buffer layer adhered to the clamping surface; when pressed down, it clamps the battery together with the limit blocks 21, providing Z-axis constraint force.

[0028] The side-sealing execution module 3 includes a hot-pressing assembly 31: integrally mounted on the linear module and driven horizontally by a servo motor. An elastic telescopic pressure plate 311: contains a built-in compression spring with a stiffness of 50 N / mm, and its lower pressing surface is a ceramic plate. Heating elements 312: symmetrically distributed Φ20mm stainless steel heating rollers on both sides of the pressure plate 311, with a polytetrafluoroethylene anti-stick coating on the surface. The roller surface is parallel to the battery side, and temperature control accuracy of ±2℃ is achieved through slip ring power supply.

[0029] The film supply module 4 includes a fixed-length cutting unit 42. The clamping mechanism consists of a vertical clamping cylinder 423 and an L-shaped pressure block 424 hinged to the end of its piston rod. The cutting blade 421 is made of tungsten steel, with its cutting edge at a 15° angle to the feed direction. The vertical clamping cylinder 423 is fixed to the side wall of the frame, with its output rod hinged to the L-shaped pressure block 424. The pressing surface is laser-engraved with a grid anti-slip texture (0.1mm depth). The clamping cylinder 423 and the cutting blade drive 422 of the cutting blade 421 are mechanically synchronized via a cam mechanism, with a downward pressure of 80N. The negative pressure flattening unit 43 includes an adsorption block 431 made of aluminum alloy, with a micropore array of 0.5mm diameter on the top surface, a pore density of 300 pores / cm² in the central area, and 100 pores / cm² in the edge area. The horizontal drive mechanism 432 is a stepper motor-driven synchronous belt that moves the adsorption block 431 along a linear guide rail 433 with a positioning accuracy of ±0.05mm. Linkage mechanism: A mechanical linkage rod group is adopted. When the cutting blade 421 moves down 3mm, the negative pressure valve is triggered to open. After the cutting is completed, the negative pressure source is turned off after a delay of 0.5s.

[0030] The method of using this utility model is as follows:

[0031] 1. The battery is positioned by the limit block 21, and the clamping drive 22 drives the battery clamping block 23 to press down and fix it.

[0032] 2. The aluminum-plastic film is conveyed to the cutting position, and the L-shaped pressure block 424 and the cutting blade 421 press down synchronously to cut;

[0033] 3. The negative pressure adsorption block 431 is activated at the moment of cutting, and after adsorbing the membrane, it is moved to the side of the battery by the horizontal drive mechanism 432.

[0034] 4. The hot pressing assembly 31 moves horizontally, and the elastic telescopic pressure plate 311 presses the film with a pressure of 200N. The heating elements 312 on both sides heat-seal at 180℃ for 5s.

[0035] Example 2: Based on the structure described in Example 1, this example improves accuracy as follows:

[0036] Heating element 312: Internally integrates a K-type thermocouple, connected to an independent PID temperature control module (control cycle 10ms), achieving a temperature difference of ≤1℃ between the two roller surfaces. Adsorption block 431: Features a height adjustment mechanism 434 (linear lifting cylinder), with an adjustment range of 0-10mm, ensuring a coplanarity error with the conveyor plane of <0.02mm. Linkage mechanism: Upgraded to an electronically controlled synchronization module, achieving ±0.02s synchronization accuracy between the cutting signal and the vacuum solenoid valve through PLC programming.

[0037] Example 3: Based on Example 2, pressure feedback closed-loop control is added: Elastic telescopic pressure plate 311: Internally embedded strain gauge pressure sensor 313, range 0-500N. The signal line of sensor 313 is connected to the main control PLC of the equipment. Control logic: When the real-time pressure deviates from the set value (e.g., 200N) by ±5%, the PLC dynamically adjusts the output force of the servo electric cylinder of the clamping drive component 22, or extends the hot-pressing time by 0.1-0.5s, achieving pressure fluctuation ≤±2%. Verification results: For batteries with a thickness fluctuation of ±0.2mm, the pressure compensation response time is 80ms, and the sealing wrinkle rate approaches zero.

[0038] This invention relates to a lithium battery sealing device that prevents aluminum-plastic film wrinkles. Through four core technologies—cutting-adsorption sequential linkage, gradient negative pressure flattening, dual-sided hot-pressing symmetrical control, and pressure closed-loop feedback—it significantly reduces the wrinkle rate of aluminum-plastic film, improves the airtightness of the packaging, and increases the yield rate. It is especially suitable for the large-scale production of high-energy-density power batteries.

[0039] Finally, it should be noted that the above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Although the utility model 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 this utility model should be included within the protection scope of this utility model.

Claims

1. A lithium battery sealing device for preventing aluminum-plastic film wrinkles, comprising a battery positioning module (2), a side sealing execution module (3), and a film supply module (4); characterized in that: The battery positioning module (2) includes a limiting block (21) and a clamping drive (22) arranged in parallel. The output end of the clamping drive (22) is connected to a battery clamping block (23). The limiting block (21) is used to constrain the horizontal displacement of the battery body (1). The battery clamping block (23) is driven by the clamping drive (22) to provide a vertical clamping force. The side sealing execution module (3) includes a horizontally movable hot pressing assembly (31). The hot pressing assembly (31) is provided with an elastic telescopic pressure plate (311) and symmetrically distributed on both sides thereof. Heating element (312), the heating working surface of the heating element (312) is parallel to the horizontal moving direction of the pressure plate; the film supply module (4) includes an aluminum-plastic film conveying unit (41), a fixed-length cutting unit (42) and a negative pressure flattening unit (43), the pressing mechanism of the fixed-length cutting unit (42) and the cutting knife (421) operate synchronously, the adsorption plane of the negative pressure flattening unit (43) is coplanar with the aluminum-plastic film conveying plane, and the fixed-length cutting unit (42) and the negative pressure flattening unit (43) are controlled by a linkage mechanism to control the execution sequence.

2. The lithium battery sealing equipment according to claim 1, characterized in that, The clamping drive (22) is a cylinder or a servo electric cylinder, and the clamping surface of the battery clamping block (23) is covered with an elastic buffer layer; the constraint surface of the limiting block (21) is adapted to the side wall shape of the battery body (1).

3. The lithium battery sealing equipment according to claim 1, characterized in that, The heating element (312) is a cylindrical heating roller with an anti-stick coating on its surface, and each heating roller is equipped with an independent temperature control module; the extension and retraction direction of the elastic telescopic pressure plate (311) is perpendicular to the axis of the heating element (312).

4. The lithium battery sealing equipment according to claim 1, characterized in that, The elastic telescopic pressure plate (311) integrates a pressure sensor (313). The signal output end of the pressure sensor (313) is connected to the equipment control system to provide real-time feedback on the sealing pressure and trigger the pressure compensation mechanism.

5. The lithium battery sealing equipment according to claim 1, characterized in that, The fixed-length cutting unit (42) includes: a cutting blade (421) with its cutting edge inclined at an acute angle along the cutting direction; a cutting blade drive (422) that drives the cutting blade (421) to move vertically; and a pressing drive mechanism including a vertical pressing cylinder (423) and an L-shaped pressing block (424) hinged to the end of its piston rod. The vertical pressing cylinder (423) is fixed to the side frame of the cutting blade (421), and the pressing surface of the L-shaped pressing block (424) is provided with anti-slip texture in the contact area between the pressing surface and the aluminum-plastic film.

6. The lithium battery sealing equipment according to claim 1, characterized in that, The negative pressure flattening unit (43) includes: an adsorption block (431) with a micropore array on its top surface and connected to a negative pressure source through a vacuum pipeline; a horizontal drive mechanism (432) for driving the adsorption block (431) to reciprocate along a horizontal guide rail (433); and a height adjustment mechanism (434) for controlling the distance between the adsorption block (431) and the aluminum-plastic film conveying plane; the micropore array distribution density of the adsorption block (431) decreases from the center to the edge.

7. The lithium battery sealing equipment according to claim 1, characterized in that, The linkage mechanism includes a mechanical linkage rod group or an electronic control synchronization module, which is used to synchronously start negative pressure adsorption when the fixed length cutting unit (42) is pressed down, and to delay the release of negative pressure after the cutting is completed.

8. The lithium battery sealing equipment according to claim 1, characterized in that, The battery clamping block (23) and the limiting block (21) adopt a quick-change installation structure, and the guide roller surface of the aluminum-plastic film conveying unit (41) is covered with flexible friction material.

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