Sealant pins

Abstract

The utility model discloses a seal glue nail, including high temperature resistant cap and elastic plug, the end face of high temperature resistant cap is equipped with recess towards elastic plug, the end face of elastic plug is equipped with extension and protruding in proper order towards high temperature resistant cap, protruding and recess cooperate, when the outer inclined side wall of protruding embeds recess, the end of extension and the bottom surface of cap are jointed. The bottom surface of high temperature resistant cap and the top surface of elastic plug form a interval area through extension, and interval area forms an air heat insulation layer, effectively slows down the transmission speed of heat from high temperature resistant cap to elastic plug and the electrolyte below in the laser welding process, significantly reduces the risk that electrolyte near injection port instantaneously gasifies and splashes because of thermal shock, avoids the gasification pressure to lift glue nail on one hand, guarantees the cleaning and dry of the welding area of sealed aluminum sheet on the other hand, thereby greatly improves the welding yield and the overall sealing reliability of battery.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, specifically to sealing nails. Background Technology

[0002] In the manufacturing process of large cylindrical batteries, after the cell is filled with electrolyte, the filling port needs to be reliably sealed. The current industry standard is to first seal the filling port with a one-piece molded plastic staple, then cover it with a thin aluminum sheet, and finally weld the aluminum sheet to the battery casing using laser welding to achieve a final seal.

[0003] However, this process has a significant drawback: during laser welding, the high temperature generated is transferred through the sealing aluminum sheet to the underlying adhesive pin. Since traditional adhesive pins are typically made of a single elastic material, their overall thermal conductivity and heat resistance are poor. During welding, especially towards the end, the accumulated heat can easily cause the electrolyte temperature near the injection port to exceed its vaporization point (usually above 80°C), leading to instantaneous vaporization and the generation of high-pressure steam. This steam poses a risk of partially lifting the sealing adhesive pin, compromising the initial seal; furthermore, the steam carrying electrolyte can splash out from any possible gaps, contaminating the welding area and severely interfering with the laser welding process of the sealing aluminum sheet, resulting in poor welding, incomplete welds, or porosity. These welding defects directly create leakage channels, ultimately affecting the long-term sealing reliability and safety of the battery, leading to a decrease in product yield. Utility Model Content

[0004] To address the technical problems encountered during welding with traditional rubber nails, this invention proposes a sealing rubber nail. An extension forms a gap between the bottom surface of the high-temperature resistant cap and the top surface of the elastic plug, creating an air insulation layer. This effectively slows down the heat transfer rate from the high-temperature resistant cap to the elastic plug and the electrolyte below during laser welding, significantly reducing the risk of instantaneous vaporization and splashing of the electrolyte near the injection port due to thermal shock.

[0005] The technical solution adopted by this utility model is as follows: a sealing nail includes a high-temperature resistant cap and an elastic plug. The high-temperature resistant cap has a groove on its end face facing the elastic plug. The elastic plug has an extension and a protrusion in sequence on its end face facing the high-temperature resistant cap. The shape of the protrusion is adapted to the groove. When the outer inclined sidewall of the protrusion is embedded in the groove, the end of the extension is engaged with the bottom surface of the cap.

[0006] Optionally, the groove has at least two opposing inwardly inclined sidewalls that extend from the opening of the groove toward the bottom of the groove, and the width of the groove cross-section gradually increases; the protrusion has at least two opposing outwardly inclined sidewalls that are adapted to the shape of the inwardly inclined sidewalls; when the protrusion is embedded in the groove, the outwardly inclined sidewalls and the inwardly inclined sidewalls fit tightly together.

[0007] Optionally, the angle α between the inner inclined sidewall and the vertical line of the groove center is 5°~15°; the angle β between the outer inclined sidewall and the vertical line of the protrusion center is 5°~15°, and α and β are equal.

[0008] Optionally, in the free state, the cross-sectional width of the protrusion at any point on its outer inclined sidewall is greater than the cross-sectional width of the groove at the corresponding height on its inner inclined sidewall.

[0009] Optionally, the groove opening edge is provided with a chamfer or rounded corner for guiding assembly, and the top edge of the protrusion is provided with a chamfer or rounded corner for guiding assembly.

[0010] Optionally, the outer wall of the high-temperature cap is provided with a first sealing slope for abutting against the surface around the injection hole, the first sealing slope extending from the top of the high-temperature cap to the inner wall.

[0011] Optionally, the end of the elastic plug away from the high-temperature cap is provided with a second sealing bevel, which extends from the body of the elastic plug toward the center.

[0012] Optionally, the plug, extension, and protrusion are integrally formed.

[0013] The beneficial effects of this invention are as follows: An extension forms a gap between the bottom surface of the high-temperature cap and the top surface of the elastic plug, creating an air insulation layer. This effectively slows down the heat transfer from the high-temperature cap to the elastic plug and the electrolyte below during laser welding. It significantly reduces the risk of instantaneous vaporization and splashing of the electrolyte near the injection port due to thermal shock. This avoids the vaporization pressure from lifting the plug and ensures the cleanliness and dryness of the welding area of ​​the sealing aluminum sheet, thereby greatly improving the welding yield and the overall sealing reliability of the battery. The sealing plug uses a split design, where the cap portion exposed to the high-temperature welding area uses a high-temperature resistant material, while the plug portion responsible for sealing uses a highly elastic material. Attached Figure Description

[0014] Figure 1 This is an exploded view of the sealing nail proposed in an embodiment of this utility model;

[0015] Figure 2This is a schematic diagram of the structure of the sealing nail proposed in an embodiment of the present utility model;

[0016] Figure 3 This is a schematic diagram showing the cooperation between the sealing glue nail and the battery body according to an embodiment of the present invention;

[0017] Figure 4 This is a schematic diagram of the battery body proposed in an embodiment of the present utility model.

[0018] The markings in the attached figures are as follows: 1. High-temperature resistant cap; 11. Groove; 111. Inner inclined sidewall; 12. First sealing slope; 2. Elastic plug; 21. Extension; 22. Protrusion; 221. Outer inclined sidewall; 23. Second sealing slope; 3. Battery body; 31. Liquid injection hole. Detailed Implementation

[0019] The present application will now be described in further detail with reference to the accompanying drawings and embodiments.

[0020] like Figures 1 to 4 As shown, this embodiment discloses a sealing nail for sealing the electrolyte filling hole of a large cylindrical battery, including a high-temperature resistant cap and an elastic plug. The high-temperature resistant cap is made of engineering plastics that can withstand high temperatures, such as PEEK (polyetheretherketone) and PI (polyimide). The elastic plug is made of a material with good elasticity and sealing performance, such as silicone rubber and fluororubber. The high-temperature resistant cap has a groove on its bottom end face facing the elastic plug. Correspondingly, the elastic plug has an integrally formed extension and a protrusion on its top end face facing the high-temperature resistant cap. During assembly, the protrusion of the elastic plug is pressed into the groove of the high-temperature resistant cap, so that the outer inclined sidewall of the protrusion fits tightly against the inner inclined sidewall of the groove. The length of the extension is such that when the protrusion is fully embedded in the groove, the end of the extension (i.e., the root connected to the protrusion) engages with the bottom surface of the high-temperature cap, thus forming a gap between the bottom surface of the high-temperature cap and the top surface of the elastic plug. This gap forms an air insulation layer, effectively slowing down the transfer of heat from the high-temperature cap to the elastic plug and the electrolyte below during laser welding. This significantly reduces the risk of instantaneous vaporization and splashing of the electrolyte near the injection port due to thermal shock. On the one hand, it prevents the vaporization pressure from lifting the plug; on the other hand, it ensures the cleanliness and dryness of the welding area of ​​the sealing aluminum sheet, thereby greatly improving the welding yield and the overall sealing reliability of the battery. The sealing plug uses a split design, where the cap part exposed to the high-temperature welding area uses a high-temperature resistant material, while the plug part responsible for sealing uses a highly elastic material.

[0021] The groove has at least two opposing inwardly inclined sidewalls that extend from the groove opening towards the bottom, with their cross-sectional width gradually increasing to form a structure similar to a "dovetail groove" or a conical groove. The protrusion has at least two opposing outwardly inclined sidewalls whose shape matches that of the inwardly inclined sidewalls. When the protrusion is embedded in the groove, the engagement of the inclined sidewalls creates a strong mechanical interlocking force, preventing easy separation under vibration or internal air pressure impact, thus ensuring the reliability of the split structure connection. The angle α between the inwardly inclined sidewall and the vertical line of the groove center is preferably 5°~15°; the angle β between the outwardly inclined sidewall and the vertical line of the protrusion center is also preferably 5°~15°, and α and β are equal or very close. This angle range provides sufficient locking force while avoiding assembly difficulties or stress concentration caused by excessively large angles. The equal angles ensure that the inner and outer sidewalls can achieve a maximum area of ​​tight fit, optimizing connection strength and stability. In the free state (unassembled state), the cross-sectional width of the protrusion at any point on its outer inclined sidewall is slightly larger than the cross-sectional width of the groove at the corresponding height on its inner inclined sidewall. During assembly, the protrusion of the elastic plug will undergo slight elastic deformation, thereby generating a continuous radial clamping force in the groove, which further enhances the firmness and sealing of the connection.

[0022] To facilitate assembly, the groove opening edge is provided with a chamfer or rounded corner for guiding assembly. Similarly, the top edge of the protrusion is also provided with a chamfer or rounded corner for guiding assembly.

[0023] The extension and protrusion are integrally molded on the elastic plug. The integral molding structure is simple and reliable, ensuring that the extension has consistent elasticity and that its length can be precisely controlled, thereby ensuring the formation of the gap area.

[0024] Furthermore, the outer wall of the high-temperature resistant cap is provided with a first sealing bevel. This first sealing bevel extends from the top of the high-temperature resistant cap towards the inner wall. When the entire sealing plug is pressed into the electrolyte filling hole of the battery body, this bevel will abut against the surface around the electrolyte filling hole and undergo elastic deformation. The first sealing bevel can form a reliable surface seal at the upper edge of the electrolyte filling hole, preventing external contaminants from entering and assisting in part of the sealing function. The end of the elastic plug away from the high-temperature resistant cap is provided with a second sealing bevel. This second sealing bevel extends from the body of the elastic plug towards the center, and the second sealing bevel first acts as a guide, facilitating the smooth insertion of part of the elastic plug into the electrolyte filling hole. When fully pressed in, the body of the elastic plug undergoes radial expansion within the hole, and the second sealing bevel fits tightly against the inner wall of the electrolyte filling hole, forming an excellent radial seal, which is the main sealing barrier.

[0025] In use, the assembled sealing pins are first pressed into the battery's filling hole. The second sealing bevel of the elastic plug and the battery body form the main seal against the hole wall, while the first sealing bevel of the high-temperature resistant cap forms an auxiliary seal at the hole opening. Laser welding of the sealing aluminum sheet is then performed. The welding heat is primarily absorbed by the high-temperature resistant cap, whose material is heat-resistant and resistant to deformation. Simultaneously, the gap between the cap and the plug effectively prevents heat from being transferred downwards, protecting the electrolyte below. This ensures the stability of the welding process and the long-term sealing reliability of the battery.

[0026] It is understood that the specific embodiments described above are merely for explaining the relevant utility model and not for limiting the utility model. It should also be noted that, for ease of description, only the parts related to the utility model are shown in the accompanying drawings. Multiple technical solutions in the same embodiment, as well as multiple technical solutions in different embodiments, can be arranged and combined to form new technical solutions that do not contradict or conflict with each other. All equivalent structural transformations made based on the content of this utility model specification and drawings, directly or indirectly applied to other related technical fields, are similarly included within the protection scope of this utility model.

Claims

1. A type of sealing nail, characterized in that, The device includes a high-temperature resistant cap and an elastic plug. The high-temperature resistant cap has a groove on its end face facing the elastic plug. The elastic plug has an extension and a protrusion on its end face facing the high-temperature resistant cap. The protrusion is adapted to the shape of the groove. When the protrusion is inserted into the groove, the end of the extension engages with the bottom surface of the cap.

2. The sealing nail according to claim 1, characterized in that, The groove has at least two opposing inwardly inclined sidewalls that extend from the opening of the groove toward the bottom, and the width of the groove cross-section gradually increases; the protrusion has at least two opposing outwardly inclined sidewalls that are adapted to the shape of the inwardly inclined sidewalls; when the protrusion is embedded in the groove, the outwardly inclined sidewalls and the inwardly inclined sidewalls fit tightly together.

3. The sealing nail according to claim 2, characterized in that, The angle α between the inner inclined sidewall and the vertical line of the center of the groove is 5°~15°, and the angle β between the outer inclined sidewall and the vertical line of the center of the protrusion is 5°~15°, and α and β are equal.

4. The sealing nail according to claim 2, characterized in that, In its free state, the cross-sectional width of the protrusion at any point on its outer inclined sidewall is greater than the cross-sectional width of the groove at the corresponding height on its inner inclined sidewall.

5. The sealing nail according to claim 1, characterized in that, The groove opening edge is provided with a chamfer or rounded corner for guiding assembly, and the top edge of the protrusion is provided with a chamfer or rounded corner for guiding assembly.

6. The sealing nail according to claim 1, characterized in that, The outer wall of the high-temperature resistant cap is provided with a first sealing slope for abutting against the surface around the injection hole. The first sealing slope extends from the top of the high-temperature resistant cap to the inner wall.

7. The sealing nail according to claim 1, characterized in that, The elastic plug has a second sealing bevel at its end away from the high-temperature cap, and the second sealing bevel extends from the body of the elastic plug toward the center.

8. The sealing nail according to claim 1, characterized in that, The plug, extension, and protrusion are integrally formed.

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