Top cover assembly

Abstract

The utility model relates to a top cover assembly, and the top cover assembly comprises a top cover plate which is provided with a first pole through hole; the pole is arranged on the top cover plate in an insulating manner and is positioned at the first pole via hole; the fixing frame is arranged on the top cover plate, the fixing frame is provided with a second pole through hole, the fixing frame extends to form an extending wall, the extending wall at least partially covers the outer edge of the pole, and a gap is reserved between the extending wall and the pole; the pole cap is arranged on the outer side of the pole in a surrounding manner and is connected with the top cover plate, the pole and the fixing frame respectively; the lower support is provided with a third pole through hole, and the top cover plate is arranged on the lower support and connected with the lower support. The top cover assembly structure has the advantages of being stable in structure and easy to assemble.

Description

Technical Field

[0001] The present disclosure relates to the technical field of battery top cover assemblies, and particularly to a top cover assembly. Background Art

[0002] In the existing power battery structure, a common square aluminum shell battery generally includes a housing, a battery cell, and a top cover assembly. The battery cell is disposed in the housing, and the top cover assembly is used to close the housing. The top cover assembly usually includes a lower bracket, a top cover plate, a sealing ring, a fixing bracket, and positive and negative bipolar columns.

[0003] When processing the above-mentioned top cover assembly, the sealing ring and the positive and negative columns are sequentially installed at the column through-holes of the top cover plate, and then the fixing bracket is welded to the top cover plate by a welding process. Then, a pole cap is formed by injection molding outside the column. This structure has the following defects:

[0004] Firstly, the connection between the column and the fixing bracket in the vertical direction mainly relies on the adhesion force after the formation of the pole cap, resulting in poor fastening performance between the column and the fixing bracket in the vertical direction, and it is easy to occur that the pole cap and the column fall off from the fixing bracket.

[0005] Secondly, the connection between the top cover plate and the lower bracket is mainly through the snap connection at the inner edge position of the column through-hole. The snap connection is easy to fall off during the production process, affecting the production efficiency and also the reliability of the finished product.

[0006] In summary, the structure of the battery top cover assembly in the prior art has certain defects and needs to be improved urgently. Utility Model Content

[0007] In order to solve the above problems existing in the prior art, the purpose of the present disclosure is to provide a top cover assembly. The top cover assembly structure of the present disclosure has the advantages of stable structure and easy assembly.

[0008] A top cover assembly according to the present disclosure includes:

[0009] A top cover plate having a first pole column through-hole penetrating along the thickness direction;

[0010] A pole column, which is insulated and disposed on the top cover plate and is located at the first pole column through-hole;

[0011] A fixing bracket, which is disposed on the top cover plate and is located outside the first pole column through-hole. The fixing bracket has a second pole column through-hole corresponding to the first pole column through-hole for accommodating the pole column. One end of the fixing bracket away from the top cover plate extends towards the direction of the pole column to form an extension wall, and at least part of the extension wall covers the outer edge of the pole column and leaves a gap with the pole column;

[0012] A pole cap, which is arranged around the outside of the pole column and is respectively connected to the top cover plate, the pole column and the fixing frame, so that the top cover plate, the fixing frame and the pole column are insulated from each other;

[0013] A lower bracket, which has a third pole column through hole penetrating along the thickness direction, and the position of the third pole column through hole corresponds to the position of the first pole column through hole. The top cover plate is arranged on the lower bracket and is connected to the lower bracket.

[0014] Preferably, one end of the pole column close to the top cover plate extends outward to form a stepped outer edge, and at least part of the stepped outer edge coincides with the extension wall in the thickness direction.

[0015] Preferably, the extension wall is parallel to the upper end face of the stepped outer edge.

[0016] Preferably, at least one outer side surface of the fixing frame is recessed inward to form a reinforcement hole.

[0017] Preferably, one end of the reinforcement hole located on the outside is a first narrow end, and one end located on the inside is a first wide end. The cross-sectional dimension of the hole channel at the first narrow end is smaller than the cross-sectional dimension of the hole channel at the first wide end.

[0018] Preferably, one end of the fixing frame close to the top cover plate extends outward to form a positioning outer edge. The top cover plate forms a positioning groove adapted to the positioning outer edge outside the first pole column through hole, and the fixing frame is embedded in the positioning groove.

[0019] Preferably, on one side of the top cover plate close to the lower bracket, a plurality of connecting concave holes are recessed in the direction away from the lower bracket. On one side of the lower bracket close to the top cover plate, heat melting columns adapted to the connecting concave holes are formed at positions corresponding to the connecting concave holes, and the heat melting columns are inserted into the connecting concave holes.

[0020] Preferably, one end of the connecting concave hole close to the lower bracket is a second narrow end, and one end away from the lower bracket is a second wide end. The cross-sectional dimension of the hole channel at the second narrow end is smaller than the cross-sectional dimension of the hole channel at the second wide end.

[0021] Preferably, the top cover assembly further includes a sealing ring, and the sealing ring is arranged between the pole column and the top cover plate;

[0022] The lower bracket is hollowed out in the middle of its length direction to form a plurality of elastic shrinkage holes.

[0023] The advantages of a top cover assembly according to the present disclosure are as follows:

[0024] 1. For the top cover assembly structure of the present disclosure, by designing that the upper end of the fixing bracket has an extension wall partially covering the outer edge of the pole column, and leaving a gap between the extension wall and the outer edge of the pole column, the pole cap colloid formed by injection molding can be filled in the gap. The extension wall limits the pole cap colloid in the vertical direction to enhance the connection stability of the three components of the pole cap, pole column, and fixing bracket in the vertical direction, effectively avoiding the phenomenon of the pole cap and pole column falling off from the fixing bracket, and enhancing the overall stability and reliability of the product;

[0025] 2. For the top cover assembly structure of the present disclosure, by providing connecting concave holes on the back of the top cover plate and hot melt posts corresponding to the connecting concave holes on the front of the lower bracket, the hot melt posts are inserted into the connecting concave holes. The hot melt posts can be melted by heating to form a colloid and filled into the connecting concave holes. After cooling and forming, the top cover plate and the lower bracket are connected. Compared with the structure of snap - fit, this connection structure greatly enhances the connection stability between the top cover plate and the lower bracket, effectively reducing the risk of the top cover plate and the lower bracket falling off, and has a simple structure and is easy to implement; Description of the Drawings

[0026] Figure 1 is a schematic structural diagram of a top cover assembly described in this embodiment;

[0027] Figure 2 is a cross - sectional view of a top cover assembly described in this embodiment at the position of the pole column through - hole;

[0028] Figure 3 is a schematic structural diagram of the front of the top cover plate described in this embodiment;

[0029] Figure 4 is a schematic structural diagram of the back of the top cover plate described in this embodiment;

[0030] Figure 5 is a schematic structural diagram of the pole column described in this embodiment;

[0031] Figure 6 is a schematic structural diagram of the initial state of the fixing bracket described in this embodiment;

[0032] Figure 7 is a schematic structural diagram of the bent extension wall of the fixing bracket described in this embodiment;

[0033] Figure 8 is a schematic structural diagram of the lower bracket described in this embodiment;

[0034] Figure 9 is a schematic assembly structure diagram of the fixing bracket and the top cover plate described in this embodiment;

[0035] Figure 10 is Figure 9 a schematic structural diagram after installing the sealing ring;

[0036] Figure 11 is Figure 10 Schematic structural diagram after the pole column is inserted;

[0037] Figure 12 is Figure 11 Schematic structural diagram after the extension wall is bent;

[0038] Figure 13 is Figure 12 Schematic structural diagram after the pole cap is formed by injection molding.

[0039] Description of reference numerals: 1 - top cover plate, 11 - first pole column through hole, 12 - positioning groove, 13 - connecting concave hole, 2 - pole column, 21 - stepped outer edge, 3 - fixing bracket, 31 - second pole column through hole, 32 - extension wall, 33 - reinforcement hole, 4 - pole cap, 5 - lower bracket, 51 - third pole column through hole, 52 - heat fusion column, 53 - elastic shrinkage hole, 6 - sealing ring, 7 - explosion-proof valve, A - solder joint position. Detailed implementation manners

[0040] As Figures 1 to 13 shown, a top cover assembly according to the present disclosure includes:

[0041] A top cover plate 1, as detailed in Figure 3 、 Figure 4 shown, the top cover plate 1 is generally in a square plate-like structure, and has a first pole column through hole 11 penetrating in the thickness direction for the pole column 2 to pass through, so that the pole column 2 can be electrically connected to the battery cell inside the battery housing. In the bipolar pole column 2 structure, the number of the first pole column through holes 11 is usually two, which are respectively distributed at both ends of the length direction of the top cover plate 1 to respectively correspond to the positive pole column and the negative pole column.

[0042] Pole columns 2, the number of which is usually two, namely the positive and negative pole columns, as detailed in Figure 5 shown, the shape and size of the pole column 2 generally correspond to the first pole column through hole 11 and are made of a conductive material. For the negative pole column, it is required that the upper part is made of aluminum material and the lower part is made of copper material. In this embodiment, the pole column 2 is in a quadrangular prism structure. In other alternative embodiments, the pole column 2 can be cylindrical or other special-shaped structures, and the present disclosure does not limit the specific shape of the pole column 2.

[0043] The pole column 2 is insulated and arranged on the top cover plate 1 and is located at the first pole column through hole 11 of the top cover plate 1.

[0044] A fixing bracket 3, which is arranged on the top cover plate 1 and is located outside the first pole column through hole 11, as detailed in Figure 6 、 Figure 7As shown, the fixing bracket 3 has a second pole post through hole 31 corresponding to the first pole post through hole 11 and used for accommodating the pole post 2. Specifically, the fixing bracket 3 is generally in a hollow frame structure, with a hollow middle part to form the second pole post through hole 31. The fixing bracket 3 is generally arranged around the first pole post through hole 11, so as to surround the outside of the pole post 2 after the pole post 2 is inserted, and play a fastening role on the pole post 2.

[0045] In this embodiment, in order to improve the fastening force of the fixing bracket 3 on the colloid of the pole cap 4 in the vertical direction after injection molding, an extension wall 32 is formed at the end of the fixing bracket 3 far from the top cover plate 1, that is, the upper end, extending towards the pole post 2. The extension wall 32 at least partially covers the outer edge of the pole post 2 and leaves a gap with the pole post 2. This structure enables the colloid to flow into the gap between the extension wall 32 and the outer edge of the pole post 2 when the pole cap 4 is formed by injection molding. After cooling and forming, the colloid below can be fastened in the vertical direction through the extension wall 32, effectively avoiding the separation of the pole cap 4 and the fixing bracket 3 in the vertical direction, and enhancing the connection stability of the three components of the pole post 2, the pole cap 4 and the fixing bracket 3 in the vertical direction.

[0046] The pole cap 4 is usually formed by injection molding with a plastic material. It is arranged around the outside of the pole post 2 and is respectively connected to the top cover plate 1, the fixing bracket 3 and the pole post 2, used to connect the three components into one body and achieve insulation and sealing between the components.

[0047] The lower bracket 5 is usually made of a plastic material and has insulation properties. The lower bracket 5 is in a long plate-shaped structure adapted to the top cover plate 1, and is combined and connected with the top cover plate 1 up and down. The lower bracket 5 is used to separate the top cover plate 1 from the battery case, insulate the top cover plate 1 from the battery case, and prevent the top cover plate 1 from contacting the battery cells inside the battery case, thus avoiding the occurrence of short circuit defects. The lower bracket 5 is provided with a third pole post through hole 51 at a position corresponding to the first pole post through hole 11.

[0048] Further, in this embodiment, as detailed in Figure 5 As shown, at one end of the pole post 2 close to the top cover plate 1, that is, the bottom end, a stepped outer edge 21 extends outward. At least part of the stepped outer edge 21 coincides with the extension wall 32 in the thickness direction, that is, the vertical direction. The stepped outer edge 21 extends a certain width outside the body of the pole post 2 to facilitate cooperation with the extension wall 32 to form an up-and-down limiting and fastening structure in the vertical direction.

[0049] Further, in this embodiment, as detailed in Figure 7As shown, the fixing bracket 3 has a frame-shaped structure. The side walls are perpendicular to the plate surface of the top cover plate 1. The extending wall 32 extends towards the pole column 2 in the middle to a position parallel to the upper end surface of the stepped outer edge 21, that is, parallel to the plate surface of the top cover plate 1, so as to form a relatively parallel glue-filling space between the extending wall 32 and the stepped outer edge 21. Thus, the glue of the pole cap 4 formed by injection molding can effectively resist the tensile force in the vertical direction, and further improve the connection stability of the three components of the pole cap 4, the pole column 2, and the fixing bracket 3 in the vertical direction.

[0050] In a specific embodiment, the number of the extending walls 32 is four groups. The four groups of extending walls 32 are respectively distributed on the four edges of the fixing bracket 3. The number of each group of extending walls 32 is two, and the two extending walls 32 are respectively located on both sides of the middle of the edge of the fixing bracket 3, so that the extending walls 32 can play a role in uniform reinforcement.

[0051] Furthermore, in this embodiment, specifically as Figure 6 shown, at least one outer side surface of the fixing bracket 3 is recessed inward to form a reinforcing hole 33. In this embodiment, the shape of the reinforcing hole 33 is a circular hole. In other alternative embodiments, the reinforcing hole 33 can be a square hole or other special-shaped holes. The reinforcing hole 33 is used to allow the glue to flow into the reinforcing hole 33 when the pole cap 4 is formed by injection molding. After cooling and forming, it can strengthen the connection stability between the pole cap 4 and the fixing bracket 3. The reinforcing holes 33 are evenly distributed on the outer side surfaces of the four edges of the fixing bracket 3 to play a role in uniform reinforcement.

[0052] Furthermore, in this embodiment, one end of the reinforcing hole 33 located on the outer side is the first narrow end, and the end located on the inner side is the first wide end. The cross-sectional size of the hole channel at the first narrow end is smaller than that at the first wide end, so that the reinforcing hole 33 has a structure with a large inner end and a small outer end, which can effectively prevent the pole cap 4 from detaching from the fixing bracket 3 in the outer direction, and further enhance the reinforcing effect of the reinforcing hole 33.

[0053] Furthermore, in this embodiment, specifically as Figure 3 、 Figure 6 shown, one end of the fixing bracket 3 close to the top cover plate 1, that is, the bottom end, extends outward to form a positioning outer edge. The top cover plate 1 forms a positioning groove 12 adapted to the positioning outer edge outside the first pole column through hole 11. The fixing bracket 3 is embedded in the positioning groove 12 through the positioning outer edge. This structure can facilitate the positioning and installation of the fixing bracket 3. At the same time, since the fixing bracket 3 and the top cover plate 1 are fixed by welding, the positioning outer edge can effectively increase the welding area between the fixing bracket 3 and the top cover plate 1, and compared with the narrow-edge structure, it can effectively enhance the welding stability between the fixing bracket 3 and the top cover plate 1.

[0054] Furthermore, in this embodiment, specifically as Figure 4 、 Figure 8As shown in the figure, on the side of the top cover plate 1 close to the lower bracket 5, that is, the back surface, several connecting concave holes 13 are formed by being recessed upward along the direction away from the lower bracket 5. Specifically, the connecting concave holes 13 are circular holes, and the number is four, which are evenly distributed on the outer periphery of the first pole through hole 11. On the side of the lower bracket 5 close to the top cover plate 1, that is, the front surface, heat melting columns 52 adapted to the connecting concave holes 13 are formed at positions corresponding to the connecting concave holes 13. After the top cover plate 1 and the lower bracket 5 are covered, the heat melting columns 52 will be inserted into the connecting concave holes 13 one by one. At this time, local heating is performed on the heat melting columns 52, which will cause the heat melting columns 52 to melt and form a colloid to fill the connecting concave holes 13. After cooling and forming, the top cover plate 1 and the lower bracket 5 are connected. Compared with the snap connection method, this connection structure can greatly enhance the connection stability between the top cover plate 1 and the lower bracket 5.

[0055] Further, in this embodiment, at one end of the connecting concave hole 13 close to the lower bracket 5, that is, the lower end, is the second narrow end, and at the end away from the lower bracket 5, that is, the upper end, is the second wide end. The cross-sectional dimension of the hole channel at the second narrow end is smaller than that at the second wide end, so that the connecting concave hole 13 has a structure with a larger upper end and a smaller lower end. This structure can form a countersunk head cylindrical structure after the colloid cools and forms, and has good tensile ability in the vertical direction, which can effectively prevent the top cover plate 1 and the lower bracket 5 from falling off and separating vertically.

[0056] Further, in this embodiment, the top cover assembly further includes a sealing ring 6. The sealing ring 6 is annular and is arranged between the pole 2 and the top cover plate 1 and is located outside the first pole through hole 11. The sealing ring 6 is used to achieve insulation and sealing between the pole 2 and the top cover plate 1.

[0057] As Figure 8 shown, several elastic shrinkage holes 53 are formed by hollowing out the middle part of the lower bracket 5 in its length direction. Since the lower bracket 5 is made of plastic material and has certain material elasticity, there may be a certain dimensional error due to external factors such as temperature change during the assembly with the top cover plate 1, resulting in inability to cover and assemble with the top cover plate 1. Therefore, in this embodiment, by hollowing out the middle part of the lower bracket 5 to form elastic shrinkage holes 53, the length of the lower bracket 5 can be finely adjusted through the elastic shrinkage holes 53 at this place, so that the lower bracket 5 adapts to the size of the top cover plate 1, improving the assembly success rate and reducing the assembly difficulty between the top cover plate 1 and the lower bracket 5.

[0058] This embodiment also provides a processing method for the top cover assembly for processing the top cover assembly as described above, including the following steps:

[0059] S01. Prepare the adapted top cover plate 1, fixing bracket 3, terminal post 2, lower bracket 5, and explosion-proof valve 7 for use. Specifically, stamp the above components using metal materials. Among them, the extension wall 32 of the fixing bracket 3 is in the initial state as shown in Figure 6 . In this state, an angle of approximately 160° is formed between the extension wall 32 and the side wall of the fixing bracket 3, that is, the extension wall 32 inclines slightly inward, but does not enter the insertion path of the terminal post 2, so that the terminal post 2 can be inserted from one end of the fixing bracket 3 with the extension wall 32 along the direction perpendicular to the plane where the fixing bracket 3 is located, that is, vertically inserted into the second terminal post through-hole 31 of the fixing bracket 3;

[0060] S02. As shown in Figure 9 , install the fixing bracket 3 outside the first terminal post through-hole 11 on the top cover plate 1, and make the extension wall 32 located at the end far from the top cover plate 1. At this time, the extension wall 32 of the fixing bracket 3 maintains the above initial state. Specifically, the fixing bracket 3 and the top cover plate 1 are fixedly connected by welding. After installing the fixing bracket 3 on the top cover plate 1, from the back of the top cover plate 1 (such as the solder joint position at A in Figure 2 ), use the penetration welding process to connect the fixing bracket 3 and the top cover plate 1;

[0061] S03. As shown in Figure 10 , take the sealing ring 6, and install the sealing ring 6 and the terminal post 2 into the first terminal post through-hole 11 of the top cover plate 1 in sequence, or pre-assemble the sealing ring 6 and the terminal post 2 and then install them into the first terminal post through-hole 11 of the top cover plate 1;

[0062] S04. As shown in Figure 11 , bend the extension wall 32 of the fixing bracket 3 towards the direction where the terminal post 2 is located by stamping, so that the extension wall 32 at least partially covers the outer edge of the terminal post 2 and leaves a gap with the terminal post 2, that is, in the state shown in Figure 12 . In this step, the extension wall 32 of the fixing bracket 3 changes from the initial state to the bent state;

[0063] S05. As shown in Figure 13 , put the integrated structure formed by the top cover plate 1, the sealing ring 6, the terminal post 2, and the fixing bracket 3 into a mold and inject plastic outside the terminal post 2 to form a terminal cap 4;

[0064] S06. Take the explosion-proof valve 7 and install it in the explosion-proof valve installation hole of the top cover plate 1;

[0065] S07. Connect the lower bracket 5 with the top cover plate 1 to obtain a top cover assembly;

[0066] S08. Automatically clamp the top cover assembly on the production line for laser QR code marking, apply a protective film to the explosion-proof valve 7, then conduct helium inspection, test the insulation resistance of the negative terminal post, the insulation withstand voltage of the negative terminal post, the resistance from the positive terminal post to the top cover plate 1, and perform shaping and other related station tests. After all tests are qualified, the finished top cover assembly of the lithium battery can be obtained;

[0067] Among them, step S06 can be switched to any step before step S02, step S03, step S04, or step S05.

[0068] In the structure of the top cover assembly of the present disclosure, by designing that the upper end of the fixing frame 3 has an extension wall 32 that partially covers the outer edge of the terminal post 2, and leaving a gap between the extension wall 32 and the outer edge of the terminal post 2, the colloid of the terminal cap 4 formed by injection molding can be filled in the gap. The extension wall 32 limits the terminal cap 4 colloid in the vertical direction to enhance the connection stability of the terminal cap 4, the terminal post 2, and the fixing frame 3 in the vertical direction, effectively avoiding the phenomenon that the terminal cap 4 and the terminal post 2 fall off from the fixing frame 3, and enhancing the overall stability and reliability of the product;

[0069] In the structure of the top cover assembly of the present disclosure, by providing a connecting concave hole 13 on the back of the top cover plate 1 and a hot melt post 52 corresponding to the connecting concave hole 13 on the front of the lower bracket 5, the hot melt post 52 is inserted into the connecting concave hole 13. The hot melt post 52 can be melted by heating to form a colloid and filled into the connecting concave hole 13. After cooling and forming, the top cover plate 1 and the lower bracket 5 are connected. Compared with the structure of snap fit, this connection structure greatly enhances the connection stability between the top cover plate 1 and the lower bracket 5, effectively reduces the risk of the top cover plate 1 and the lower bracket 5 falling off, and has a simple structure and is easy to implement;

[0070] In the description of the present disclosure, it should be understood that the orientation or positional relationship indicated by orientation words such as "front, back, up, down, left, right", "horizontal, vertical, horizontal", and "top, bottom" is usually based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present disclosure and simplifying the description. Without contrary instructions, these orientation words do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation on the protection scope of the present disclosure.

[0071] For those skilled in the art, according to the technical solutions and concepts described above, various corresponding changes and deformations can be made, and all these changes and deformations should fall within the protection scope of the claims of the present disclosure.

Claims

1. A top cover assembly, characterized in that, Comprising: A top cover plate having a first pole post through-hole penetrating in the thickness direction; A pole post, which is insulated and arranged on the top cover plate and is located at the first pole post through-hole; A fixing frame, which is arranged on the top cover plate and is located outside the first pole post through-hole. The fixing frame has a second pole post through-hole corresponding to the first pole post through-hole for accommodating the pole post. One end of the fixing frame away from the top cover plate extends towards the pole post to form an extending wall, and at least part of the extending wall covers the outer edge of the pole post and leaves a gap with the pole post; A pole cap, which is arranged around the outside of the pole post and is respectively connected to the top cover plate, the pole post and the fixing frame to insulate the top cover plate, the fixing frame and the pole post from each other; A lower bracket having a third pole post through-hole penetrating in the thickness direction, and the position of the third pole post through-hole corresponds to the position of the first pole post through-hole. The top cover plate is arranged on the lower bracket and is connected to the lower bracket.

2. The top cover assembly according to claim 1, wherein, One end of the pole post close to the top cover plate extends outwards to form a stepped outer edge, and at least part of the stepped outer edge coincides with the extending wall in the thickness direction.

3. The top cover assembly according to claim 2, wherein, The extending wall is parallel to the upper end surface of the stepped outer edge.

4. The top cover assembly according to claim 1 or 2 or 3, characterized in that, At least one outer side surface of the fixing frame is recessed inwards to form a reinforcing hole.

5. The top cover assembly according to claim 4, wherein One end of the reinforcing hole located outside is a first narrow opening end, and one end located inside is a first wide opening end. The cross-sectional dimension of the hole channel at the first narrow opening end is smaller than the cross-sectional dimension of the hole channel at the first wide opening end.

6. The top cover assembly according to claim 1 or 2 or 3 or 5, characterized in that, One end of the fixing frame close to the top cover plate extends outwards to form a positioning outer edge. The top cover plate forms a positioning groove adapted to the positioning outer edge outside the first pole post through-hole, and the fixing frame is embedded in the positioning groove.

7. The top cover assembly according to claim 1, wherein One surface of the top cover plate close to the lower bracket is recessed in the direction away from the lower bracket to form a plurality of connecting concave holes. On one surface of the lower bracket close to the top cover plate, heat melting columns adapted to the connecting concave holes are formed at positions corresponding to the connecting concave holes, and the heat melting columns are inserted into the connecting concave holes.

8. The top cover assembly according to claim 7, characterized in that, One end of the connecting concave hole close to the lower bracket is a second narrow opening end, and one end away from the lower bracket is a second wide opening end. The cross-sectional dimension of the hole channel at the second narrow opening end is smaller than the cross-sectional dimension of the hole channel at the second wide opening end.

9. The top cover assembly according to claim 1, wherein, It further includes a sealing ring, and the sealing ring is arranged between the pole post and the top cover plate; A plurality of elastic shrinkage holes are formed by hollowing out the middle part of the lower bracket in its length direction.

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