Double-seal nut fastening cylindrical battery cell

Abstract

The utility model relates to battery technical field, concretely relates to a double -layer sealing nut fastening cylindrical battery core. The utility model provides a double -layer sealing nut fastening cylindrical battery core, including the casing, the one end of casing is provided with through -hole, the one end of stud passes through the through -hole, and the stud is equipped with first sealing ring, the nut is equipped with second sealing ring in, and the nut can be connected with stud thread, the wedge washer is connected in the stud outside, along the axial direction of battery core, the wedge washer sets up between the nut and casing, and the wedge washer includes upper washer and lower washer, and the combined surface of upper washer, lower washer is provided with the wedge tooth that can adapt respectively, along the axial direction of battery core, the insulating washer sets up between the wedge washer and casing. The utility model can strengthen the structure stability after nut fastening, need not adopt laser welding to carry out fusion welding to the nut and stud, and the double -layer sealing ring inside and outside the casing can effectively guarantee the battery core sealing effect.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, specifically to a method of securing cylindrical battery cells with a double-layer sealing nut. Background Technology

[0002] Large cylindrical battery cells possess advantages such as high energy density, low manufacturing cost, and high manufacturing efficiency, and are widely used in new energy vehicles, energy storage, and consumer electronics. As demand for large cylindrical battery cells continues to grow, cell manufacturers are constantly expanding their production capacity. However, the sealing safety and welding yield of the large cylindrical battery cell manufacturing process constrain its development, prompting major cell manufacturers to actively develop new large cylindrical battery cell structures and assembly technologies.

[0003] Currently, various sealing structures are used in large cylindrical battery cells, most of which employ laser welding for sealing and fixing. This method is costly and has difficulty controlling welding yield. Some large cylindrical battery cells use a nut-tightening structure for sealing assembly. To prevent the nut from loosening due to vibration, the nut and stud need to be fused together, which also leads to a series of problems. The stud, as the battery cell electrode post, is fastened to the shell and the nut. Usually, a sealing ring is only installed on the stud inside the shell to fit with the shell hole, resulting in a single sealing method and a risk of seal failure. Existing sealing structures for large cylindrical battery cells have the following technical problems: high frequency of laser welding, high investment in lasers, and difficulty in controlling yield; reliance on nut tightening alone carries the risk of loosening due to vibration; and a single sealing method is prone to failure. Utility Model Content

[0004] To address the technical problems of high investment costs and difficulty in controlling yield of existing cylindrical battery cell sealing structures, this utility model provides a double-layer sealing nut for fastening cylindrical battery cells. This enhances the structural stability after the nut is fastened, eliminates the need for laser welding of the nut and stud, and the double-layer sealing rings inside and outside the housing effectively ensure the sealing effect of the battery cell.

[0005] This utility model provides a double-layer sealing nut for fastening a cylindrical battery cell, comprising: a housing, one end of which has a through hole; a stud, one end of which passes through the through hole and the other end of which is inside the housing and fixedly connected to a collector plate, the stud being fitted with a first sealing ring and positioned between the stud and the housing; a nut, containing a second sealing ring, the nut being threadedly connected to the stud and the second sealing ring being positioned between the nut and the stud; a wedge-shaped washer, fitted around the stud and positioned between the nut and the housing along the axial direction of the battery cell, the wedge-shaped washer comprising an upper washer and a lower washer that can engage with each other, the mating surfaces of the upper and lower washers respectively being provided with matching wedge-shaped teeth; and an insulating gasket, positioned between the wedge-shaped washer and the housing along the axial direction of the battery cell.

[0006] Furthermore, the included angle between the wedge-shaped tooth surfaces of the mating surfaces of the upper and lower washers is greater than the helix angle of the stud thread.

[0007] Furthermore, a fixing part is provided at the end of the nut facing the stud, and the fixing part abuts against the wedge-shaped washer along the axial direction of the battery cell.

[0008] Furthermore, the end of the nut facing the stud is provided with a snap-fit ​​groove for snapping the second sealing ring, and the end of the second sealing ring facing the stud abuts against the end of the first sealing ring facing the nut for sealing.

[0009] Furthermore, the second sealing ring has a stepped first limiting part on one end edge facing the nut, and the snap-fit ​​groove has a second limiting part that matches the first limiting part.

[0010] Furthermore, the first sealing ring includes a first sealing part and a second sealing part, the stud includes a threaded part and a base, the threaded part is distributed along the axial direction of the battery cell and has a threaded part that is threaded to connect with the nut, the base is fixedly connected to the threaded part, the base is distributed along a direction perpendicular to the axial direction of the battery cell and the base is disposed inside the housing; the first sealing part is disposed between the threaded part and the wedge washer, and the second sealing part is disposed between the base and the housing.

[0011] Furthermore, along a plane perpendicular to the axis of the battery cell, the projection of the wedge-shaped washer lies within the projection range of the insulating gasket.

[0012] Furthermore, along a plane perpendicular to the axial direction of the battery cell, the projection of the base lies within the projection range of the first sealing ring.

[0013] The beneficial effects of this utility model are as follows:

[0014] This invention can enhance the structural stability after the nut is tightened, eliminating the need for laser welding to weld the nut and stud. The double-layer sealing rings inside and outside the shell can effectively ensure the sealing effect of the battery cell.

[0015] The battery cell assembly method is simple, which can reduce equipment investment costs and improve production efficiency. The application of wedge-shaped washers and nuts with embedded second sealing rings can enhance the structural stability after the nuts are tightened. There is no need to use laser welding to weld the nuts and studs, thus avoiding defective battery cells with laser-induced burn marks or ablation of sealing rings or insulation sheets. The double-layer sealing rings inside and outside the shell can effectively ensure the sealing effect of the battery cell and avoid leakage problems.

[0016] The upper and lower washers have wedge-shaped teeth at their meshing points, and their surfaces have radial fine teeth. During tightening, these radial fine teeth increase the coefficient of friction on the contact surfaces, and the wedge-shaped teeth engage and lock the bolt. Furthermore, the included angle A between the wedge-shaped teeth of the washers is greater than the helix angle B of the stud thread. When loosening occurs, the amount of axial thickening of the washer is greater than the amount of axial creep of the thread, thus increasing the axial preload of the bolt and effectively suppressing loosening caused by vibration. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a structural schematic diagram of one embodiment of the present invention.

[0019] Explanation of key figure labels:

[0020] 1-Stud; 2-First sealing ring; 3-Housing; 4-Insulating gasket; 5-Wedge washer; 6-Second sealing ring; 7-Nut. Detailed Implementation

[0021] To enable those skilled in the art to better understand the technical solutions of this utility model, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this utility model.

[0022] One embodiment of this utility model provides a double-layer sealing nut 7 for fastening a cylindrical battery cell, including a housing 3. One end of the housing 3 is provided with a through hole. One end of a stud 1 passes through the through hole, and the other end of the stud 1 is inside the housing 3 and fixedly connected to a current collector. A first sealing ring 2 is fitted onto the stud 1 and is disposed between the stud 1 and the housing 3. The current collector is welded to the stud 1 for housing assembly. The stud 1 with the first sealing ring 2 passes through the through hole at the top of the housing 3. The first sealing ring 2 includes a first sealing part and a second sealing part, which are integrally formed. The stud 1 includes a threaded part and a base, which are integrally formed. The threaded part is distributed along the axial direction of the battery cell and has a threaded part that is threadedly connected to the nut 7. The base is fixedly connected to the threaded part and is distributed along a direction perpendicular to the axial direction of the battery cell. The base is disposed inside the housing 3 and has a larger area than the through hole. The base abuts against the second sealing part, which serves as a limiting function. The first sealing part is disposed between the threaded part and the wedge-shaped washer 5, and the second sealing part is disposed between the base and the housing 3. Along a plane perpendicular to the axial direction of the battery cell, the projection of the base lies within the projection range of the second sealing part, ensuring insulation performance.

[0023] A second sealing ring 6 is provided inside the nut 7. The end of the nut 7 facing the stud 1 has a locking groove for engaging the second sealing ring 6. The end of the second sealing ring 6 facing the stud 1 abuts against the end of the first sealing ring 2 facing the nut 7 for sealing. The edge of the end of the second sealing ring 6 facing the nut 7 has a stepped first limiting portion. The locking groove has a second limiting portion that matches the first limiting portion. The second sealing ring 6 is embedded in the locking groove. The nut 7 can be threadedly connected to the stud 1, and the second sealing ring 6 is located between the nut 7 and the stud 1.

[0024] A wedge-shaped washer 5 is fitted onto the outside of the stud 1, along the axial direction of the battery cell. The wedge-shaped washer 5 is positioned between the nut 7 and the housing 3. The wedge-shaped washer 5 includes an upper washer and a lower washer that can interlock. The mating surfaces of the upper and lower washers are respectively provided with matching wedge-shaped teeth. The surfaces of the upper and lower washers have radial fine teeth. When tightened, the radial fine teeth on the washers increase the coefficient of friction of the contact surfaces, and the wedge-shaped teeth engage and lock. The included angle A between the wedge-shaped teeth of the washers is greater than the thread helix angle B of the stud 1. When loosening occurs, the amount of axial thickening of the washer is greater than the amount of axial creep of the thread, thereby increasing the axial preload of the bolt and effectively suppressing loosening caused by vibration. A second sealing ring 6 is embedded inside the nut 7, forming a double seal with the first sealing ring 2 on the stud 1. The end of the nut 7 facing the stud 1 has a slightly larger fixing part. Along the axial direction of the battery cell, the fixing part abuts against the wedge-shaped washer 5. When the nut 7 is tightened, the fixing part compresses the second sealing ring 6 and the first sealing ring 2 to form a seal. The first sealing ring 2 is embedded inside the nut 7. After tightening, the friction between the stud 1 and the nut 7 is increased, thereby enhancing the stability of the structure.

[0025] An insulating gasket 4 is provided between the wedge-shaped washer 5 and the housing 3 along the axial direction of the battery cell. The insulating gasket 4 is injection molded from the shoulder of the cylindrical housing 3 with the through hole as the center. In a plane perpendicular to the axial direction of the battery cell, the projection of the wedge-shaped washer 5 is located within the projection range of the insulating gasket 4, ensuring the insulation effect.

[0026] Although the present invention has been described in detail with reference to the accompanying drawings and preferred embodiments, the present invention is not limited thereto. Various equivalent modifications or substitutions can be made to the embodiments of the present invention by those skilled in the art without departing from the spirit and essence of the present invention, and such modifications or substitutions should all be within the scope of the present invention. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should also be included within the protection scope of the present invention.

Claims

1. A method for securing a cylindrical battery cell with a double-layer sealing nut, characterized in that, include: The housing has a through hole at one end; A stud has one end that passes through a through hole and the other end that is inside the housing and fixedly connected to the manifold. The stud is fitted with a first sealing ring, which is located between the stud and the housing. The nut has a second sealing ring inside, and the nut can be threadedly connected to the stud with the second sealing ring located between the nut and the stud. A wedge-shaped washer is fitted onto the outside of the stud along the axial direction of the battery cell. The wedge-shaped washer is positioned between the nut and the housing. The wedge-shaped washer includes an upper washer and a lower washer that can engage with each other. The mating surfaces of the upper and lower washers are respectively provided with wedge-shaped teeth that can be adapted. An insulating gasket is placed between the wedge-shaped washer and the housing along the axial direction of the battery cell.

2. The method for securing a cylindrical battery cell with a double-layer sealing nut as described in claim 1, characterized in that, The included angle between the wedge-shaped tooth surfaces of the mating surfaces of the upper and lower washers is greater than the helix angle of the stud thread.

3. The method for securing a cylindrical battery cell with a double-layer sealing nut as described in claim 1, characterized in that, The end of the nut facing the stud has a fixing part, which abuts against the wedge-shaped washer along the axial direction of the battery cell.

4. The method for securing a cylindrical battery cell with a double-layer sealing nut as described in claim 1, characterized in that, The end of the nut facing the stud is provided with a snap-fit ​​groove for snapping the second sealing ring, and the end of the second sealing ring facing the stud abuts against the end of the first sealing ring facing the nut for sealing.

5. A method for securing a cylindrical battery cell with a double-layer sealing nut as described in claim 4, characterized in that, The second sealing ring has a stepped first limiting part on one end edge facing the nut, and the snap-fit ​​groove has a second limiting part that matches the first limiting part.

6. The method for securing a cylindrical battery cell with a double-layer sealing nut as described in claim 1, characterized in that, The first sealing ring includes a first sealing part and a second sealing part. The stud includes a threaded part and a base. The threaded part is distributed along the axial direction of the battery cell and has a threaded part that is threaded to connect with the nut. The base is fixedly connected to the threaded part. The base is distributed along a direction perpendicular to the axial direction of the battery cell and is disposed inside the housing. The first sealing part is disposed between the threaded part and the wedge-shaped washer, and the second sealing part is disposed between the base and the housing.

7. A method for securing a cylindrical battery cell with a double-layer sealing nut as described in claim 1, characterized in that, In a plane perpendicular to the axis of the battery cell, the projection of the wedge-shaped washer lies within the projection range of the insulating gasket.

8. A method for securing a cylindrical battery cell with a double-layer sealing nut as described in claim 1, characterized in that, Along a plane perpendicular to the axis of the battery cell, the projection of the base lies within the projection range of the first sealing ring.

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