Top cover assembly and machining method thereof

Abstract

The invention relates to a top cover assembly and a processing method thereof, 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 machining method is used for machining the top cover assembly. The top cover assembly structure has the advantages of being stable in structure and easy to assemble. The machining method has the advantages that the production difficulty is low, the sealing performance of the sealing ring cannot be affected, welding slag is easy to clean, and the welding slag is prevented from affecting the product quality.

Description

Technical Field

[0001] The present disclosure relates to the technical field of battery top cover assemblies, and in particular to a top cover assembly and a processing method thereof. Background Art

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

[0003] When processing the above-mentioned top cover assembly, the sealing ring and the positive and negative poles are sequentially installed into the pole through holes of the top cover plate, and then the fixing frame is welded to the top cover plate by welding process, and then the pole cap is formed by injection molding outside the pole by injection molding process. This structure and processing method have the following defects:

[0004] First, the vertical connection between the pole and the fixing frame mainly relies on the bonding force of the pole cap after molding, which results in poor fastening performance between the pole and the fixing frame in the vertical direction, and the pole cap and the pole are prone to fall off from the fixing frame;

[0005] Secondly, the top cover plate and the lower bracket are mainly connected by snap-fitting at the edge of the pole through-hole. The snap-fitting method is easy to fall off during the production process, affecting the production efficiency and the reliability of the finished product.

[0006] Thirdly, the prior art mainly adopts the assembly sequence of first assembling the sealing ring and the pole, and then welding the fixing frame. This assembly sequence, on the one hand, is prone to loosening and displacement of the positive and negative poles and the sealing ring during welding, which increases the difficulty of production. On the other hand, since the sealing ring and the buckle structure are both located close to the pole through-hole, the high temperature generated when welding the fixing frame will be transmitted to the sealing ring and the buckle structure. The sealing ring is easily deformed by the high temperature, which affects the sealing performance. The high temperature will also affect the elasticity and shape of the buckle, further reducing the stability of the buckle fit between the top cover plate and the lower bracket. In addition, the welding slag generated during the welding process is easily stuck in the gap between the pole and the sealing ring, which is inconvenient to clean. Moreover, since the welding slag is a metal part with conductivity, it is easy to affect the insulation between the pole, the fixing frame and the top cover plate, resulting in the problem of short circuit and scrapping of the product.

[0007] In summary, the structure and processing method of the battery top cover assembly in the prior art have certain defects and need to be improved urgently. Summary of the invention

[0008] To solve the problems existing in the above-mentioned prior art, the present disclosure aims to provide a top cover assembly and a processing method thereof. The top cover assembly of the present disclosure has the advantages of stable structure and easy assembly, and the processing method of the present disclosure has the advantages of low production difficulty, no influence on the sealing performance of the sealing ring, and easy cleaning of welding slag, avoiding the influence of welding slag on the product quality.

[0009] A top cover assembly described in the present disclosure includes:

[0010] A top cover plate having a first pole post through-hole penetrating in the thickness direction;

[0011] A pole post, which is insulated and arranged on the top cover plate and is located at the first pole post through-hole;

[0012] 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 far from the top cover plate extends towards the pole post to form an extension wall, and at least part of the extension wall covers the outer edge of the pole post and leaves a gap with the pole post;

[0013] 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;

[0014] A lower bracket having a third pole post through-hole penetrating in the thickness direction. The position of the third pole post through-hole corresponds to the position of the first pole post through-hole, and the top cover plate is arranged on the lower bracket and is connected to the lower bracket.

[0015] Preferably, one end of the pole post 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.

[0016] Preferably, the extension wall is parallel to the upper end surface of the stepped outer edge.

[0017] Preferably, at least one outer side surface of the fixing frame is recessed inward to form a reinforcing hole.

[0018] Preferably, one end of the reinforcing hole located outside is a first narrow end, and one end located inside is a first wide end, and 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.

[0019] Preferably, one end of the fixing frame close to the top cover plate extends outward to form a positioning outer edge, and a positioning groove adapted to the positioning outer edge is formed outside the first pole post through-hole of the top cover plate, and the fixing frame is embedded in the positioning groove.

[0020] Preferably, on one side of the top cover plate close to the lower bracket, a plurality of connecting concave holes are formed by recessing in a 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.

[0021] Preferably, one end of the connecting concave hole close to the lower bracket is a second narrow end, and the 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 that at the second wide end.

[0022] 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;

[0023] A plurality of elastic shrinkage holes are formed by hollowing out the middle part of the lower bracket in its length direction.

[0024] A processing method of a top cover assembly according to the present disclosure, which is used to process the top cover assembly as described above, includes the following steps:

[0025] S01. Prepare a top cover plate, a fixing frame, a pole column and a lower bracket that are adapted. Among them, the extension wall of the fixing frame is in an initial state, so that the pole column can be inserted into the second pole column through hole of the fixing frame from one end of the fixing frame with the extension wall along a direction perpendicular to the plane where the fixing frame is located;

[0026] S02. Install the fixing frame outside the first pole column through hole on the top cover plate, and make the extension wall located at one end away from the top cover plate;

[0027] S03. Take a sealing ring, and install the sealing ring and the pole column at the first pole column through hole of the top cover plate in sequence, or pre-assemble the sealing ring and the pole column and then install them at the first pole column through hole of the top cover plate;

[0028] S04. Bend the extension wall of the fixing frame towards the direction where the pole column is located, so that the extension wall at least partially covers the outer edge of the pole column and leaves a gap with the pole column;

[0029] S05. Put the integrated structure formed by the top cover plate, the sealing ring, the pole column and the fixing frame into a mold and inject plastic outside the pole column to form a pole cap;

[0030] S06. Take an explosion-proof valve and install it in the explosion-proof valve installation hole of the top cover plate;

[0031] S07. Connect the lower bracket with the top cover plate to obtain the top cover assembly;

[0032] S08. Mark the obtained top cover assembly, attach a protective film at the explosion-proof valve, and then conduct helium inspection and insulation withstand voltage detection. After passing the tests, the finished top cover assembly of the lithium battery is obtained;

[0033] Among them, step S06 can be switched to any step before step S02, step S03, step S04, and step S05.

[0034] An advantage of the top cover assembly and its processing method disclosed in the present disclosure is that:

[0035] 1. In the structure of the top cover assembly of the present disclosure, by designing that the upper end of the fixing frame has an extension wall that partially covers 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 pole cap, pole column, and fixing frame in the vertical direction, effectively avoiding the phenomenon that the pole cap and pole column fall off from the fixing frame, and enhancing the overall stability and reliability of the product;

[0036] 2. In the structure of the top cover assembly of the present disclosure, by providing a connecting concave hole on the back of the top cover plate and a hot melt column corresponding to the connecting concave hole on the front of the lower bracket, the hot melt column is inserted into the connecting concave hole. The hot melt column can be melted by heating to form a colloid and filled into the connecting concave hole. After cooling and forming, the top cover plate is connected to the lower bracket. Compared with the snap-fit structure, 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;

[0037] 3. In the processing method of the present disclosure, by setting the initial state and bent state of the fixing frame, first keep the fixing frame in the initial state, and the upper end is available for the pole column to be vertically inserted. After welding the fixing frame to the top cover plate, then assemble the sealing ring and the pole column, and then make the extension wall bend to partially cover the outer edge of the pole column through stamping, so as to play a role in strengthening the connection after the pole cap is formed by injection molding. The processing method of the present disclosure avoids the phenomenon of loosening and displacement of the pole column and the sealing ring during the welding process, reduces the production difficulty, and at the same time avoids the problem that the high temperature generated during the welding process causes the sealing ring to be heated and deformed, affecting the sealing performance, ensuring the sealing performance of the product. In addition, since the pole column and the sealing ring are not assembled during welding, the welding slag generated during welding is easy to clean, and there is no problem that the welding slag affects the insulation between components. More prominently, the extension wall of the present disclosure does not affect the insertion of the pole column and the sealing ring in the initial state. After insertion, the extension wall covers the outer edge of the pole column by bending. During this process, there is no need to adjust the position of the pole column, such as rotation. This method can be adapted to various shapes of pole columns, such as square, round, and other special-shaped pole columns, making the processing method of the present disclosure have good versatility and can be applied to the processing of top cover assemblies with various pole column shapes. Brief Description of the Drawings

[0038] Figure 1 is a schematic structural view of a top cover assembly described in this embodiment;

[0039] Figure 2 is a sectional view of a top cover assembly described in this embodiment at the position of the pole post through hole;

[0040] Figure 3 is a schematic structural view of the front of the top cover plate described in this embodiment;

[0041] Figure 4 is a schematic structural view of the back of the top cover plate described in this embodiment;

[0042] Figure 5 is a schematic structural view of the pole post described in this embodiment;

[0043] Figure 6 is a schematic structural view of the initial state of the fixing bracket described in this embodiment;

[0044] Figure 7 is a schematic structural view of the extended wall of the fixing bracket after being bent;

[0045] Figure 8 is a schematic structural view of the lower bracket described in this embodiment;

[0046] Figure 9 is a schematic assembly structure view of the fixing bracket and the top cover plate described in this embodiment;

[0047] Figure 10 is Figure 9 a schematic structural view after installing the sealing ring;

[0048] Figure 11 is Figure 10 a schematic structural view after installing the pole post;

[0049] Figure 12 is Figure 11 a schematic structural view of the extended wall after being bent;

[0050] Figure 13 is Figure 12 a schematic structural view after injection molding the pole cap.

[0051] Description of the reference numerals: 1 - top cover plate, 11 - first pole post through hole, 12 - positioning groove, 13 - connecting concave hole, 2 - pole post, 21 - stepped outer edge, 3 - fixing bracket, 31 - second pole post through hole, 32 - extended wall, 33 - reinforcement hole, 4 - pole cap, 5 - lower bracket, 51 - third pole post through hole, 52 - hot melt post, 53 - elastic shrinkage hole, 6 - sealing ring, 7 - explosion-proof valve, A - solder joint position. Detailed Description of the Invention

[0052] As Figures 1 to 13 shown, a top cover assembly described in the present disclosure includes:

[0053] A top cover plate 1, as detailed in Figure 3 and Figure 4 shown, the top cover plate 1 is generally in a square plate-like structure, which has a first pole post through hole 11 penetrating along the thickness direction for the pole post 2 to pass through, so that the pole post 2 can be electrically connected to the battery cell inside the battery case. In the bipolar pole post 2 structure, the number of the first pole post through holes 11 is generally two, which are respectively distributed at both ends of the top cover plate 1 in the length direction to respectively correspond to the positive pole post and the negative pole post.

[0054] The pole posts 2, the number of which is generally two, are respectively the positive and negative pole posts, as detailed in Figure 5 shown, the shape and size of the pole posts 2 generally correspond to the first pole post through holes 11 and are made of conductive materials. For the negative pole post, 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 posts 2 are in a quadrangular prism structure. In other alternative embodiments, the pole posts 2 can be cylindrical or other special-shaped structures. The present disclosure does not limit the specific shape of the pole posts 2.

[0055] The pole posts 2 are insulatingly arranged on the top cover plate 1 and are located at the first pole post through holes 11 of the top cover plate 1.

[0056] A fixing frame 3, which is arranged on the top cover plate 1 and is located outside the first pole post through holes 11, as detailed in Figure 6 and Figure 7 shown, the fixing frame 3 has a second pole post through hole 31 corresponding to the first pole post through holes 11 for accommodating the pole posts 2. Specifically, the fixing frame 3 is generally in a hollow frame structure, and the middle part is hollow to form the second pole post through hole 31. The fixing frame 3 is generally arranged around the first pole post through holes 11 to surround the outside of the pole posts 2 after the pole posts 2 are inserted, so as to play a fastening role on the pole posts 2.

[0057] In this embodiment, in order to improve the fastening force of the fixing frame 3 on the colloid of the pole cap 4 in the vertical direction after injection molding, one end of the fixing frame 3 far from the top cover plate 1, that is, the upper end, extends towards the pole posts 2 to form an extension wall 32. The extension wall 32 at least partially covers the outer edge of the pole posts 2 and leaves a gap with the pole posts 2. This structure enables the colloid to flow into the gap between the extension wall 32 and the outer edge of the pole posts 2 when the pole cap 4 is injection molded. After cooling and forming, the extension wall 32 can vertically fasten the colloid below, effectively avoiding the separation of the pole cap 4 and the fixing frame 3 in the vertical direction and enhancing the connection stability of the three components of the pole posts 2, the pole cap 4, and the fixing frame 3 in the vertical direction.

[0058] The pole cap 4 is usually formed by injection molding with a plastic material. It is disposed around the outside of the pole column 2 and is respectively connected to the top cover plate 1, the fixing frame 3 and the pole column 2, and is used to connect the three components into one body and achieve insulating sealing between the components.

[0059] The lower bracket 5 is usually made of a plastic material and has insulation properties. The lower bracket 5 is in the shape of a long plate structure adapted to the top cover plate 1, and is connected to the top cover plate 1 with upper and lower covers. 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, thereby avoiding the occurrence of short circuit defects. The lower bracket 5 is provided with a third pole column through hole 51 at a position corresponding to the first pole column through hole 11.

[0060] Further, in this embodiment, specifically as Figure 5 shown, at one end of the pole column 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 extending 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 column 2 to facilitate cooperation with the extending wall 32 to form an upper and lower limiting and fastening structure in the vertical direction.

[0061] Further, in this embodiment, specifically as Figure 7 shown, the fixing frame 3 is in a frame structure, and the side wall is 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 be 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, and further enable the glue of the pole cap 4 formed by injection molding to effectively resist the tensile force in the vertical direction, thereby improving the connection stability of the pole cap 4, the pole column 2 and the fixing frame 3 in the vertical direction.

[0062] 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 frame 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 frame 3, so that the extending walls 32 can play a uniform strengthening role.

[0063] Further, in this embodiment, specifically as Figure 6 shown, at least one outer side surface of the fixing frame 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 molding, the connection stability between the pole cap 4 and the fixing frame 3 can be enhanced. The reinforcing holes 33 are uniformly distributed on the outer side surfaces of the four edges of the fixing frame 3 to play a uniform strengthening role.

[0064] Further, in this embodiment, one end of the reinforcing hole 33 located on the outer side is the first narrow end, and one end located on the inner side is the first wide end. The cross-sectional dimension of the hole channel at the first narrow end is smaller than that of the hole channel at the first wide end, so that the reinforcing hole 33 has a structure with a larger inner end and a smaller outer end, which can effectively prevent the pole cap 4 from detaching from the fixing frame 3 in the outer direction, and further enhances the reinforcing effect of the reinforcing hole 33.

[0065] Further, in this embodiment, specifically as Figure 3 , Figure 6 shown, at one end of the fixing frame 3 close to the top cover plate 1, that is, the bottom end extends outward to form a positioning outer edge. A positioning groove 12 adapted to the positioning outer edge is formed on the outer side of the first pole post through hole 11 of the top cover plate 1. The fixing frame 3 is embedded in the positioning groove 12 through the positioning outer edge. This structure facilitates the positioning and installation of the fixing frame 3. At the same time, since the fixing frame 3 and the top cover plate 1 are fixed by welding, the positioning outer edge can effectively increase the welding area between the fixing frame 3 and the top cover plate 1, and compared with the narrow-side structure, it can effectively enhance the welding stability between the fixing frame 3 and the top cover plate 1.

[0066] Further, in this embodiment, specifically as Figure 4 , Figure 8 shown, on the side of the top cover plate 1 close to the lower bracket 5, that is, the back surface, a plurality of connecting concave holes 13 are formed by recessing upward along the direction away from the lower bracket 5, that is, upward. 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 post 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.

[0067] Further, in this embodiment, 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 the end far 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 of the hole channel 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 capacity in the vertical direction, which can effectively prevent the top cover plate 1 and the lower bracket 5 from separating up and down.

[0068] Further, in this embodiment, the top cover assembly further includes a sealing ring 6. The sealing ring 6 is annular and is disposed between the pole column 2 and the top cover plate 1 and outside the first pole column through-hole 11. The sealing ring 6 is used to achieve insulation sealing between the pole column 2 and the top cover plate 1.

[0069] As Figure 8 shown, a plurality of elastic shrinkage holes 53 are formed by hollowing out the middle part of the lower bracket 5 in its length direction. A plurality of 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 a certain material elasticity, there may be a certain dimensional error due to external factors such as temperature change during assembly with the top cover plate 1, resulting in inability to be assembled with the top cover plate 1 by covering. Therefore, in this embodiment, by forming elastic shrinkage holes 53 by hollowing out the middle part of the lower bracket 5, the lower bracket 5 can be finely adjusted in length 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.

[0070] 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:

[0071] S01. Prepare the adapted top cover plate 1, fixing frame 3, pole column 2, lower bracket 5 and explosion-proof valve 7 for use. Specifically, the above components are obtained by stamping using metal materials. Among them, the extension wall 32 of the fixing frame 3 is in the initial state as Figure 6 shown. In this state, an angle of about 160° is formed between the extension wall 32 and the side wall of the fixing frame 3, that is, the extension wall 32 is slightly inclined inward, but does not enter the insertion path of the pole column 2, so that the pole column 2 can be inserted from one end of the fixing frame 3 with the extension wall 32 along the direction perpendicular to the plane where the fixing frame 3 is located, that is, vertically inserted into the second pole column through-hole 31 of the fixing frame 3;

[0072] S02. As Figure 9 shown, install the fixing frame 3 outside the first pole column 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 frame 3 maintains the above initial state. Specifically, the fixing frame 3 and the top cover plate 1 are fixedly connected by welding. After installing the fixing frame 3 on the top cover plate 1, from the back of the top cover plate 1 (such as Figure 2 the solder joint position at A in the figure), the fixing frame 3 and the top cover plate 1 are connected by penetration welding;

[0073] S03. As Figure 10 shown, take the sealing ring 6 and install the sealing ring 6 and the pole column 2 in sequence at the first pole column through-hole 11 of the top cover plate 1, or pre-assemble the sealing ring 6 and the pole column 2 and then install them at the first pole column through-hole 11 of the top cover plate 1;

[0074] S04, as Figure 11 shown, by stamping, the extension wall 32 of the fixing bracket 3 is bent towards the direction of the pole column 2, so that the extension wall 32 at least partially covers the outer edge of the pole column 2, and there is a gap between the extension wall 32 and the pole column 2, that is, as Figure 12 shown in the state, in this step, the extension wall 32 of the fixing bracket 3 changes from the initial state to the bent state;

[0075] S05, as Figure 13 shown, the integrated structure formed by the top cover plate 1, the sealing ring 6, the pole column 2 and the fixing bracket 3 is placed in a mold and an end cap 4 is injection-molded outside the pole column 2;

[0076] S06, take the explosion-proof valve 7 and install it in the explosion-proof valve 7 installation hole of the top cover plate 1;

[0077] S07, connect the lower bracket 5 with the top cover plate 1 to obtain the top cover assembly;

[0078] S08, perform laser QR code marking on the top cover assembly through an automated clamping production line operation, and stick a protective film of the explosion-proof valve 7 at the explosion-proof valve 7, then perform helium inspection, negative pole column insulation resistance, negative pole column insulation withstand voltage, positive pole column to top cover plate 1 resistance, shaping and other related station tests. After all tests are qualified, the finished product of the top cover assembly of the lithium battery is obtained;

[0079] Among them, step S06 can be switched to any step before step S02, step S03, step S04, and step S05.

[0080] For the top cover assembly structure of the present disclosure, by designing that the upper end of the fixing bracket 3 has an extension wall 32 that partially covers the outer edge of the pole column 2, and there is a gap between the extension wall 32 and the outer edge of the pole column 2, the colloid of the end cap 4 formed by injection molding can be filled in the gap. The extension wall 32 limits the colloid of the end cap 4 in the vertical direction to enhance the connection stability of the end cap 4, the pole column 2 and the fixing bracket 3 in the vertical direction, and can effectively avoid the phenomenon that the end cap 4 and the pole column 2 fall off from the fixing bracket 3, and enhance the overall stability and reliability of the product;

[0081] For the top cover assembly structure of the present disclosure, by providing a connecting concave hole 13 on the back of the top cover plate 1 and a hot melt column 52 corresponding to the connecting concave hole 13 on the front of the lower bracket 5, the hot melt column 52 is inserted into the connecting concave hole 13. The hot melt column 52 can be melted by heating and then the formed colloid is filled into the connecting concave hole 13. After cooling and forming, the top cover plate 1 is connected with the lower bracket 5. Compared with the structure of snap fit, this connecting 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;

[0082] The processing method of the present disclosure sets the initial state and bent state of the fixing bracket 3. First, the fixing bracket 3 is kept in the initial state, and the upper end is available for the pole column 2 to be vertically inserted. After welding the fixing bracket 3 to the top cover plate 1, the sealing ring 6 and the pole column 2 are assembled. Then, the extending wall 32 is bent by stamping to partially cover the outer edge of the pole column 2, so as to play a role in strengthening the connection after the pole cap 4 is formed by injection molding. The processing method of the present disclosure avoids the phenomenon that the pole column 2 and the sealing ring 6 are loosened and displaced during the welding process, reduces the production difficulty, and at the same time avoids the problem that the sealing ring 6 is deformed by heat due to the high temperature generated during the welding process, affecting the sealing performance, ensuring the sealing performance of the product. In addition, since the pole column 2 and the sealing ring 6 are not assembled during welding, the welding slag generated by welding is easy to clean, and there is no problem that the welding slag affects the insulation between components. More prominently, the extending wall 32 of the present disclosure does not affect the insertion of the pole column 2 and the sealing ring 6 in the initial state. After insertion, the extending wall 32 is bent to cover the outer edge of the pole column 2. During this process, there is no need to adjust the position of the pole column 2 such as rotation, so that this method can be adapted to pole columns 2 of various shapes, such as square, circular and other special-shaped pole columns 2, making the processing method of the present disclosure have good versatility and can be applied to the processing of top cover assemblies with various pole column 2 shapes.

[0083] 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 understood as a limitation on the protection scope of the present disclosure.

[0084] 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 insulatively arranged on the top cover plate and is located at the first pole post through-hole; A fixing bracket, which is arranged on the top cover plate and is located outside the first pole post through-hole. The fixing bracket 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 bracket 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 bracket to insulate the top cover plate, the fixing bracket and the pole post from each other; A lower bracket having a third pole post through-hole penetrating in the thickness direction. The position of the third pole post through-hole corresponds to the position of the first pole post through-hole, and 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, characterized in that, 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 bracket 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 bracket 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 bracket 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 a 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, wherein 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; The middle part of the lower bracket in its length direction is hollowed out to form a plurality of elastic shrinkage holes.

10. A processing method for a top cover assembly, which is used to process the top cover assembly according to any one of claims 1-9, characterized in that, Including the following steps: S01. Prepare a top cover plate, a fixing bracket, a pole post and a lower bracket that are adapted. Among them, the extending wall of the fixing bracket is in an initial state, so that the pole post can be inserted into the second pole post through-hole of the fixing bracket from one end of the fixing bracket with the extending wall along a direction perpendicular to the plane where the fixing bracket is located; S02. Install the fixing bracket outside the first pole post through-hole on the top cover plate and make the extending wall located at the end away from the top cover plate; S03. Take the sealing ring, and install the sealing ring and the pole post at the first pole post through-hole of the top cover plate in sequence, or pre-assemble the sealing ring and the pole post and then install them at the first pole post through-hole of the top cover plate; S04. Bend the extension wall of the fixing bracket towards the direction where the pole column is located, so that the extension wall at least partially covers the outer edge of the pole column and leaves a gap between the extension wall and the pole column; S05. Place the integral structure formed by the top cover plate, the sealing ring, the pole column and the fixing bracket into a mold and injection mold an end cap outside the pole column; S06. Install the explosion-proof valve in the explosion-proof valve installation hole of the top cover plate; S07. Connect the lower bracket to the top cover plate to obtain the top cover assembly; S08. Mark the obtained top cover assembly, stick a protective film at the explosion-proof valve, and then conduct helium inspection and insulation withstand voltage detection. After passing the test, the finished product of the top cover assembly of the lithium battery is obtained; Among them, step S06 can be switched to any step before step S02, step S03, step S04, and step S05.

Images