Square aluminum shell liquid injection hole sealing structure

Abstract

The utility model discloses a square aluminum shell liquid injection hole sealing structure which comprises a top cover and a liquid injection hole formed in the top cover, a countersunk head is arranged on the top cover, the liquid injection hole is formed in the center of the countersunk head, a sealing rubber nail is movably arranged in the liquid injection hole, a sealing aluminum nail is arranged in the countersunk head, a protruding part is arranged on the sealing aluminum nail, and the protruding part is connected with the liquid injection hole. And the sealing rubber nail is extruded through the protruding part, so that the sealing rubber nail leaves the liquid injection hole. The length of the protruding part is larger than the depth of the liquid injection hole, and the outer diameter of the protruding part is smaller than the diameter of the liquid injection hole. A net bag part is arranged on the lower portion of the top cover, and air passing holes are formed in the net bag part. And a welding groove is formed in the sealing aluminum nail. The countersunk head is in wedge-shaped fit with the edge of the sealing aluminum nail. The aperture of the air hole is smaller than the outer diameter of the sealant nail. According to the sealing aluminum nail, the protruding part is arranged on the sealing aluminum nail, so that the sealing aluminum nail can press down the sealing glue nail in the liquid injection hole in the press-fitting process, helium can overflow from a leakage point after sealing welding through the liquid injection hole, and welding detection is facilitated.

Description

Technical Field

[0001] This utility model relates to the field of battery packaging structure, specifically a square aluminum shell liquid injection hole sealing structure. Background Technology

[0002] The electrolyte injection port of a square aluminum-cased lithium battery is the only channel for electrolyte to enter the cell after welding around the top cover. After electrolyte injection, the injection port needs to be sealed with sealing aluminum nails. The reliability of the seal is related to the battery's safety performance. Industry testing of seal reliability typically involves pre-filling the casing with a certain amount of helium, pre-sealing with sealing nails after helium injection, inserting the sealing nails after electrolyte injection, and then laser welding the sealing aluminum nails. During laser welding of the sealing aluminum nails, defects such as incomplete welds and bursts often occur due to equipment instability and impurities in the welding area, requiring helium testing to check the weld's sealing performance. Currently, the sealing nail structure used in the market seals the internal helium inside the cell after helium filling and nailing to prevent helium from escaping from the casing during the sealing nail welding process after battery transfer. After pre-sealing, the subsequent process after battery transfer uses laser welding to weld the sealing aluminum nails to the countersunk hole position of the electrolyte injection port. After welding, a second helium test is performed to check the sealing performance. In traditional secondary helium detection methods, even if there is a leak in the sealing aluminum nail, the presence of the pre-sealed rubber nail has already achieved a sealing effect, preventing helium from leaking out through the sealing rubber nail. Therefore, the helium mass spectrometer cannot detect the leak in the sealing aluminum nail, resulting in a missed detection. Due to the aging of the rubber nail during long-term use, it is easy for it to detach from the filling hole. Batteries that have not been leak-tested pose a serious safety hazard. Utility Model Content

[0003] The purpose of this invention is to provide a sealing structure for a square aluminum shell injection hole, so as to solve the problem that the sealing performance of the aluminum sealing nail cannot be effectively tested due to the use of sealing nails for the injection hole.

[0004] To achieve the above objectives, this utility model provides the following technical solution: a square aluminum shell liquid injection hole sealing structure, including a top cover and a liquid injection hole disposed on the top cover. A countersunk head is provided on the top cover, and the liquid injection hole is located at the center of the countersunk head. A sealing rubber nail is movably disposed in the liquid injection hole, and a sealing aluminum nail is disposed in the countersunk head. The sealing aluminum nail is provided with a protrusion, and the sealing rubber nail is dislodged from the liquid injection hole by the protrusion pressing the sealing rubber nail.

[0005] Preferably, the length of the protrusion is greater than the depth of the injection hole, and the outer diameter of the protrusion is smaller than the diameter of the injection hole. This allows the protrusion to expel the sealing glue pin from the injection hole.

[0006] Preferably, the lower part of the top cover is provided with a mesh pocket, and the mesh pocket is provided with an air vent.

[0007] Preferably, the sealing aluminum nail is provided with a welding groove.

[0008] Preferably, the countersunk head and the edge of the sealing aluminum nail are wedge-shaped. This arrangement facilitates press-fitting and also serves as a centering and positioning tool.

[0009] Preferably, the diameter of the vent hole is smaller than the outer diameter of the sealing nail. This design prevents the sealing nail from falling out of the vent hole and avoids it entering the battery cell.

[0010] Preferably, the sealing nail includes a sealing section and a gap section. The sealing section is interference-fitted with the injection hole, and an air gap is provided between the gap section and the injection hole. During pre-installation, the gap section of the sealing nail is installed to the injection hole, and the gap between the gap section and the injection hole allows for helium injection. After injection, the sealing nail is pressed down, and the tight fit between the sealing section and the injection hole prevents helium leakage.

[0011] Compared with the prior art, the beneficial effects of the present invention are:

[0012] The square aluminum shell liquid injection hole sealing structure of this utility model has a protrusion on the sealing aluminum nail, which allows the sealing aluminum nail to be pressed out of the liquid injection hole during the pressing process. After being pressed out, the sealing nail falls into the mesh bag and will not enter the battery cell. Since there is no sealing nail in the liquid injection hole after the sealing welding, helium can overflow from the leakage point after the sealing welding through the liquid injection hole. Helium detection equipment can easily detect the leaking defective battery and avoid product safety risks caused by leakage in the future. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the pre-installed structure of the sealing nail of this utility model;

[0014] Figure 2 This is a schematic diagram of the sealing nail installation structure of this utility model;

[0015] Figure 3 This is a schematic diagram of the sealing aluminum nail press-fit structure of this utility model;

[0016] Figure 4 This is a schematic diagram of the structure after the sealing aluminum nail of this utility model is installed.

[0017] Reference numerals: 1. Top cover; 11. Countersunk head; 12. Mesh pocket; 13. Vent hole; 2. Liquid injection hole; 3. Sealing nail; 4. Sealing aluminum nail; 41. Protrusion; 42. Welding groove. Detailed Implementation

[0018] To make the technical means, creative features, objectives and effects of this utility model easier to understand, the present utility model will be further described below in conjunction with specific embodiments.

[0019] In the description of this utility model, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicating orientation or position, are based on the orientation or positional relationships shown in the accompanying drawings. They are used only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0020] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," and "connected," etc., should be interpreted broadly. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0022] like Figures 1 to 4 As shown, the square aluminum shell liquid injection hole sealing structure of this embodiment includes a top cover 1 and a liquid injection hole 2 disposed on the top cover 1. A countersunk head 11 is provided on the top cover 1, and the liquid injection hole 2 is located at the center of the countersunk head 11. A sealing nail 3 is movably disposed within the liquid injection hole 2. This movable arrangement means that the sealing nail 3 can move downwards and detach from the liquid injection hole 2 under external pressure. A sealing aluminum nail 4 is disposed within the countersunk head 11, and the sealing aluminum nail 4 has a protrusion 41. The protrusion 41 compresses the sealing nail 3, causing the sealing nail 3 to leave the liquid injection hole 2. The length of the protrusion 41 is greater than the depth of the liquid injection hole 2, and the outer diameter of the protrusion 41 is smaller than the diameter of the liquid injection hole 2. A mesh pocket 12 is provided at the lower part of the top cover 1, and an vent hole 13 is provided on the mesh pocket 12. The diameter of the vent hole 13 is smaller than the outer diameter of the sealing nail 3, in order to catch any fallen sealing nails 3. A welding groove 42 is provided on the sealing aluminum nail 4. Countersunk head 11 and sealing aluminum nail 4 have a wedge-shaped fit at their edges.

[0023] The sealing nail 3 includes a sealing section and a gap section. The sealing section is press-fitted with the injection hole 2, and a gas passage gap is provided between the gap section and the injection hole 2. The sealing section is a cylindrical structure that is press-fitted with the injection hole 2, and the gap section is a structure with a size smaller than the injection hole 2, which can be a conical structure, a cylindrical structure, or a structure with the same size as the sealing section (with a gas passage groove on the surface). In short, the upper structure of the sealing nail 3 is press-fitted with the injection hole 2, which can seal the helium gas after press-fitting; the lower structure has a gap with the injection hole 2, and helium gas can enter through the gas passage gap when the upper structure is not press-fitted.

[0024] In this embodiment, the sealing aluminum nail 4 is T-shaped. The upper part of the sealing aluminum nail 4 is an aluminum disc, and the bottom of the disc has a raised cylinder called the protrusion 41, with a chamfer at the bottom of the cylinder. During the welding process of the sealing aluminum nail 4, the sealing nail 3 can be squeezed out of the injection hole 2, so that the sealing nail 3 falls into the mesh bag part 12. During helium testing, helium gas can flow out through the injection hole 2 to detect the welding effect of the sealing aluminum nail 4 and avoid leakage.

[0025] In this embodiment, the sealing aluminum nail 4 is mainly used after the secondary liquid injection. After the secondary liquid injection is completed, the traditional sealing adhesive nail 3 is used for pre-filling with helium, such as... Figure 1 As shown, helium is filled through the gap;

[0026] like Figure 2 As shown, after helium filling is completed, full pressing is performed. After full pressing, the sealant nail 3 is pressed into the injection hole 2. At this time, because of the sealant nail 3, the helium gas cannot overflow from the injection hole 2.

[0027] During the battery transfer sealing nail welding process, such as Figure 3 As shown, the sealing aluminum nail 4 is first loaded. Before welding the sealing nail, a tooling is used to press the sealing aluminum nail 4 into the countersunk head 11 until it is in place. Figure 4 As shown, the sealing aluminum nail 4 is then welded. During the pressing process of the sealing aluminum nail 4, the sealing nail 3 is squeezed out of the injection hole 2 by the protrusion 41 and falls into the net bag 12. The injection hole is in a clear state. If there is a leak point after the sealing aluminum nail 4 is welded, helium can pass through the injection hole 2 and overflow from the leak point. This can effectively detect whether the sealing aluminum nail 4 is leaking, effectively test the sealing performance of the sealing aluminum nail weld, and ensure the safety of the battery for long-term use.

[0028] The above description is merely an embodiment of this utility model, and common knowledge regarding specific structures and characteristics is not described in detail here. It will be apparent to those skilled in the art that this utility model is not limited to the details of the above exemplary embodiments, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this utility model. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of this utility model is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this utility model. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A sealing structure for a liquid injection hole in a square aluminum shell, comprising a top cover (1) and a liquid injection hole (2) disposed on the top cover (1), wherein a countersunk head (11) is disposed on the top cover (1), and the liquid injection hole (2) is disposed at the center of the countersunk head (11), characterized in that: A sealing nail (3) is movably disposed inside the injection hole (2), and a sealing aluminum nail (4) is disposed inside the countersunk head (11). A protrusion (41) is provided on the sealing aluminum nail (4). The sealing nail (3) is squeezed by the protrusion (41) so that the sealing nail (3) leaves the injection hole (2).

2. The square aluminum shell liquid injection hole sealing structure according to claim 1, characterized in that: The length of the protrusion (41) is greater than the depth of the injection hole (2), and the outer diameter of the protrusion (41) is smaller than the diameter of the injection hole (2).

3. The square aluminum shell injection hole sealing structure according to claim 1, characterized in that: The top cover (1) is provided with a net bag (12) at the bottom, and the net bag (12) is provided with an air vent (13).

4. The square aluminum shell injection hole sealing structure according to claim 1, characterized in that: The sealing aluminum nail (4) is provided with a welding groove (42).

5. The square aluminum shell injection hole sealing structure according to claim 1, characterized in that: The countersunk head (11) and the sealing aluminum nail (4) are wedge-shaped fits at their edges.

6. The square aluminum shell injection hole sealing structure according to claim 3, characterized in that: The diameter of the vent (13) is smaller than the outer diameter of the sealing nail (3).

7. The sealing structure for the liquid injection hole of the square aluminum shell according to claim 1, characterized in that: The sealing nail (3) includes a sealing section and a gap section. The sealing section is interference-fitted with the injection hole (2), and an air gap is provided between the gap section and the injection hole (2).

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