Top cover plate and battery

Abstract

The invention relates to the field of batteries, and discloses a top cover plate and a battery. The top cover plate comprises a plate body and two pole assemblies arranged on the plate body, a pole hole is formed in the plate body, each pole assembly comprises a pole body and a pressing ring, each pole body is arranged on the plate body and located on one side of the corresponding pole hole, and a step structure is arranged on the periphery of each pole body; the pressing ring sleeves the periphery of the step structure of the pole body, and one end, facing the plate body, of the pressing ring is fixedly connected with the plate body. The battery comprises a bottom shell, a battery cell and the top cover plate. According to the top cover plate, the pole body of the pole assembly is arranged on one side of the plate body, the size of the pole body is reduced, the material cost is reduced, the energy density of the battery cell is improved, the safety of the battery cell is improved, the step structure is arranged on the periphery of the pole body, and the pole body is pressed to the plate body through the pressing ring, so that the position of the pole body is limited, and the safety of the battery cell is improved. And the phenomenon that the pole body falls off is avoided, so that the production yield is improved, and the production efficiency is further improved.

Description

Technical Field

[0001] This invention relates to the field of batteries, and more specifically to a top cover and a battery. Background Technology

[0002] With the development of new energy sources and the increasing application of batteries in energy storage and electric vehicles, the safety of power batteries is becoming increasingly important. However, the high cost of power batteries prevents the widespread adoption of large-capacity batteries in low-end models and low-cost applications. Therefore, the cost of existing batteries needs to be further reduced. To address this, a safe and low-cost sealed top-cover assembly needs to be developed. New energy power batteries are typically secondary batteries, also known as rechargeable batteries or accumulators. These are batteries that can be recharged after discharge to reactivate the active materials and continue to be used. Existing secondary batteries typically include pouch cells or hard-shell cells, and a key component of hard-shell cells is the top cover. The top cover has two terminals, one used as the positive terminal and the other as the negative terminal. Current terminal designs have the following drawbacks:

[0003] (1) The pole penetrates the top and bottom surfaces of the top cover plate. The pole is large in volume, has high cost, low energy density of the cell, and the composite poles that penetrate the top cover plate are at risk of disintegration, which leads to the risk of disintegration of the top cover plate and reduces the safety of the top cover plate.

[0004] (2) The pole is easy to fall off, resulting in a low yield rate and low production efficiency. Summary of the Invention

[0005] In order to solve the above-mentioned technical problems, or at least partially solve the above-mentioned technical problems, the present invention provides a top cover plate and a battery.

[0006] This invention provides a top cover plate, including a plate body and two pole post assemblies disposed on the plate body. The plate body has pole post holes, and the pole post assembly includes:

[0007] An electrode post, disposed on the plate and located on one side of the electrode post hole, has a stepped structure on its outer periphery; and

[0008] A pressure ring is sleeved on the outer periphery of the stepped structure of the pole piece, and one end of the pressure ring facing the plate is fixedly connected to the plate.

[0009] Optionally, the pole piece includes a pole piece body and a kit fitted around the outer periphery of the pole piece body, wherein the outer periphery of the kit is provided with the stepped structure.

[0010] Optionally, the pole body includes a first column and a second column arranged coaxially, the diameter of the second column is larger than the diameter of the first column, the second column is disposed on the side of the plate, and the kit is sleeved on the outer periphery of the stepped surfaces of the first column and the second column.

[0011] Optionally, the outer periphery of the second column facing the first column is provided with a torque-enhancing port, and the kit is provided with a torque-enhancing block at a position corresponding to the torque-enhancing port.

[0012] Optionally, the outer periphery of the second column on the side opposite to the first column is provided with a socket, and the kit is provided with a plug at a position corresponding to the socket.

[0013] Optionally, the kit includes a first sleeve and a second sleeve, the diameter of the second sleeve being larger than the diameter of the first sleeve. The first sleeve is fitted around the outer periphery of the first column, and the second sleeve is fitted around the outer periphery of the second column. The outer peripheries of the first sleeve and the second sleeve form the stepped structure. One end of the pressure ring is welded to the plate, and the other end of the pressure ring is pressed against the end face of the second sleeve.

[0014] Optionally, the outer periphery of the kit is provided with a limiting block, and the pressure ring is provided with a limiting groove at a position corresponding to the limiting block.

[0015] Optionally, the pole assembly further includes a protective member sleeved on the outer periphery of the pressure ring, with one end of the protective member facing the plate body supported on the side of the plate body, a limiting hole being formed on the pressure ring, and a limiting protrusion being provided on the inner side of the protective member at a position corresponding to the limiting hole.

[0016] Optionally, a sealing element is provided between the pole body and the plate body;

[0017] And / or, the side of the plate body opposite to the pole body is provided with an insulating plate, the side of the plate body opposite to the pole body is provided with a snap hole, and the insulating plate is provided with a snap that matches the snap hole.

[0018] The present invention also provides a battery, including a bottom shell with an open top, a battery cell disposed inside the bottom shell, and the aforementioned top cover plate, wherein the top cover plate is disposed at the open end of the bottom shell, and the battery cell is connected to an electrode post on the top cover plate.

[0019] The technical solution provided by the embodiments of the present invention has the following advantages compared with the prior art:

[0020] The top cover plate provided by this invention has the electrode post of the electrode post assembly located on one side of the plate body, which reduces the volume of the electrode post, lowers material costs, and compresses the physical space of the top cover plate, thereby reducing the overall volume of the top cover plate and thus increasing the energy density of the battery cell. In addition, since the electrode post is located on one side of the plate body, even if the electrode post disintegrates, it will not cause the plate body to disintegrate, thus avoiding safety accidents and improving the safety of the battery cell. Furthermore, the outer periphery of the electrode post has a stepped structure to press the electrode post against the plate body through a pressure ring, thereby restricting the position of the electrode post and preventing the electrode post from falling off, thereby improving the production yield and thus improving production efficiency. Attached Figure Description

[0021] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, those skilled in the art can obtain other drawings based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the structure of the top cover plate according to an embodiment of the present invention;

[0024] Figure 2 This is an exploded view of the top cover plate according to an embodiment of the present invention;

[0025] Figure 3 This is a cross-sectional view of the top cover plate according to an embodiment of the present invention;

[0026] Figure 4 yes Figure 3 A magnified view of a section at point A in the middle;

[0027] Figure 5 yes Figure 3 A magnified view of a section at point B in the middle;

[0028] Figure 6 This is a schematic diagram of the welding position of the pressure ring according to an embodiment of the present invention;

[0029] Figure 7 This is a schematic diagram of the structure of the pole piece according to an embodiment of the present invention;

[0030] Figure 8 This is a cross-sectional view of the pole body according to an embodiment of the present invention;

[0031] Figure 9 This is a schematic diagram of the structure of the pole body according to an embodiment of the present invention;

[0032] Figure 10 This is a schematic diagram of the structure of the kit described in an embodiment of the present invention;

[0033] Figure 11 This is a schematic diagram of the pressure ring structure according to an embodiment of the present invention;

[0034] Figure 12 This is a schematic diagram of the structure of the protective component according to an embodiment of the present invention.

[0035] Explanation of reference numerals in the attached figures

[0036] 1. Plate body; 11. Pole post hole; 2. Pole post assembly; 21. Pole post body; 211. Stepped structure; 212. Pole post body; 2121. First post; 2122. Second post; 21221. Torque enhancement port; 21222. Insert; 213. Kit; 2131. Torque enhancement block; 2132. Insert block; 2133. First set; 2134. Second set; 2135. Limiting block; 22. Pressure ring; 221. Limiting groove; 222. Limiting hole; 23. Protective component; 231. Limiting protrusion; 232. Annular insert plate; 3. Sealing component; 4. Insulating plate. Detailed Implementation

[0037] To better understand the above-mentioned objectives, features, and advantages of the present invention, the solutions of the present invention will be further described below. It should be noted that, unless otherwise specified, the embodiments and features of the present invention can be combined with each other.

[0038] The following description sets forth many specific details in order to provide a full understanding of the invention, but the invention may also be practiced in other ways different from those described herein; obviously, the embodiments described in the specification are only some, not all, of the embodiments of the invention.

[0039] Combination Figures 1 to 6 As shown, the top cover plate provided in this embodiment of the invention includes a plate body 1 and two terminal post assemblies 2 disposed on the plate body 1. The plate body 1 is provided with terminal post holes 11, wherein there are two terminal post holes 11, and one terminal post assembly 2 is installed at the position of each terminal post hole 11. One terminal post assembly 2 is used as the positive terminal of the battery, and the other terminal post assembly 2 is used as the negative terminal of the battery.

[0040] The electrode assembly 2 includes an electrode body 21 and a pressure ring 22. The electrode body 21 is disposed on the plate 1 and located on one side of the electrode hole 11. Specifically, the electrode body 21 is located on the side of the plate 1 away from the bottom shell. The outer periphery of the electrode body 21 is provided with a stepped structure 211, wherein the stepped structure 211 should make the diameter of the electrode body 21 near the plate 1 larger than the diameter of the electrode body 21 away from the plate 1.

[0041] The pressure ring 22 is sleeved on the outer periphery of the stepped structure 211 of the pole body 21, and one end of the pressure ring 22 facing the plate body 1 is fixedly connected to the plate body 1, that is, one end of the pressure ring 22 is fixedly connected to the plate body 1, and the other end of the pressure ring 22 is pressed against the stepped surface of the stepped structure 211 of the pole body 21, so as to limit the pole body 21 on the plate body 1 by the pressure ring 22.

[0042] The top cover plate provided by the present invention has the electrode post 21 of the electrode post assembly 2 disposed on one side of the plate body 1, which reduces the volume of the electrode post 21, reduces material costs, compresses the physical space of the top cover plate, and thus reduces the overall volume of the top cover plate, thereby improving the energy density of the battery cell. In addition, since the electrode post 21 is disposed on one side of the plate body 1, even if the electrode post 21 disintegrates, it will not cause the plate body 1 to disintegrate, thereby avoiding safety accidents and improving the safety of the battery cell. Furthermore, the outer periphery of the electrode post 21 is provided with a stepped structure 211, which presses the electrode post 21 against the plate body 1 through the pressure ring 22, thereby restricting the position of the electrode post 21 and preventing the electrode post 21 from falling off, thereby improving the production yield and thus improving production efficiency.

[0043] In some implementations, combined Figures 4 to 8 As shown, the electrode post 21 includes an electrode post body 212 and a sleeve 213 fitted around the outer periphery of the electrode post body 212. The outer periphery of the sleeve 213 is provided with a stepped structure 211. The sleeve 213 can be injection molded from a plastic sheet.

[0044] In this design, the pressure ring 22 presses against the stepped surface of the stepped structure 211 of the kit 213 to restrict the movement of the pole body 212 and the kit 213 in the axial direction of the pole body 212, thereby preventing the pressure ring 22 from acting directly on the pole body 212 and allowing the kit 213 to protect the pole body 212.

[0045] In other embodiments, the pole piece 21 can also be manufactured by an assembly process, and can be designed according to actual needs.

[0046] In some implementations, combined Figure 8 and Figure 9 As shown, the pole body 212 includes a first column 2121 and a second column 2122 coaxially arranged. The diameter of the second column 2122 is larger than the diameter of the first column 2121. The second column 2122 is disposed on the side of the plate 1. The kit 213 is sleeved on the outer periphery of the stepped surface of the first column 2121 and the second column 2122.

[0047] In this design, the pole body 212 also adopts a stepped design. When the kit 213 is fitted onto the outer periphery of the stepped surfaces of the first pole 2121 and the second pole 2122, the kit 213, which is limited by the pressure ring 22, can apply a force toward the plate 1 to the second pole 2122, thereby limiting the position of the pole body 212 in the axial direction of the pole body 212 and ensuring the firmness of the pole body 212 positioning.

[0048] In some implementations, such as Figure 9 The second column 2122 has a torque-enhancing port 21221 on its outer periphery facing the first column 2121, such as... Figure 10 As shown, a torque enhancement block 2131 is provided at a position corresponding to the torque enhancement port 21221 of the kit 213. The torque enhancement block 2131 matches the torque enhancement port 21221 so that the torque enhancement block 2131 can be inserted into the torque enhancement port 21221, and the torque enhancement block 2131 and the torque enhancement port 21221 are limited along the circumferential direction of the second column 2122.

[0049] In this design, the circumferential positioning between the second column 2122 and the kit 213 can be achieved through the snap-fit ​​between the torque enhancement block 2131 and the torque enhancement port 21221, thereby avoiding the phenomenon of relative rotation between the kit 213 and the pole column 21, and increasing the compactness and stability of the structure.

[0050] In some embodiments, there are multiple torque enhancement blocks 2131 and multiple torque enhancement ports 21221, and the multiple torque enhancement blocks 2131 and multiple torque enhancement ports 21221 are evenly arranged, with each torque enhancement block 2131 corresponding to one torque enhancement port 21221. This design can further enhance the circumferential limiting effect.

[0051] In some embodiments, the outer periphery of the side of the second column 2122 facing away from the first column 2121 is provided with a socket 21222, and the assembly 213 is provided with a plug 2132 at a position corresponding to the socket 21222. The plug 2132 matches the socket 21222 so that the plug 2132 can be inserted into the socket 21222, and the plug 2132 and the socket 21222 are limited along the circumferential direction of the second column 2122.

[0052] This design further enhances the circumferential positioning between the second pillar 2122 and the kit 213 through the insert 2132 and the socket 21222. Furthermore, a C-shaped overmolded structure can be formed between the socket 21222 and the second pillar 2122, increasing the positioning effect of the kit 213 and the second pillar 2122 along the axial direction of the second pillar 2122. This prevents the kit 213 from detaching after assembly onto the pole body 212, thereby improving production yield and efficiency.

[0053] The design of the second column 2122 and the kit 213 in this application, through the connection of the socket 21222 and the plug 2132 and the torque enhancement port 21221 and the torque enhancement block 2131, can increase the Z-axis anti-torsional torque of the top cover assembly, increase the dynamic anti-torsional performance of the battery cell, and thus provide dynamic safety of the battery cell.

[0054] In some embodiments, there are multiple plug blocks 2132 and multiple sockets 21222, and the multiple plug blocks 2132 and multiple sockets 21222 are evenly arranged, with each plug block 2132 corresponding to one socket 21222.

[0055] In some embodiments, multiple sockets 21222 and multiple torque-enhancing ports 21221 are staggered along the circumferential direction of the second column 2122.

[0056] This design avoids affecting the structural strength of the second column 2122, while ensuring that the second column 2122 is subjected to more uniform force in the circumferential direction, thus preventing local damage to the second column 2122.

[0057] In some implementations, combined Figure 8 and Figure 10 As shown, the kit 213 includes a first body 2133 and a second body 2134. The diameter of the second body 2134 is larger than the diameter of the first body 2133, where the diameter refers to the outer diameter of the first body 2133 and the second body 2134. The first body 2133 is fitted around the outer periphery of the first column 2121, and the second body 2134 is fitted around the outer periphery of the second column 2122. The outer peripheries of the first body 2133 and the second body 2134 form a stepped structure 211. One end of the pressure ring 22 is welded to the plate 1, and the other end of the pressure ring 22 is pressed against the end face of the second body 2134. Thus, the welded pressure ring 22 applies a force to the second body 2134 in the direction of the plate 1, ensuring the axial limiting effect of the kit 213. In addition, the kit 213 is fitted onto the stepped surface of the first column 2121 and the second column 2122, ensuring the axial limiting effect of the kit 213 on the pole body 212.

[0058] In some implementations, such as Figure 6As shown, the thickness of the weld pattern between the pressure ring 22 and the top cover should be greater than the vertical depth at that position of the pressure ring 22 to ensure the strength of the weld and increase the ultimate thrust of the finished top cover in the vertical direction.

[0059] In some implementations, such as Figure 10 As shown, the outer periphery of the kit 213 is provided with a limiting block 2135, and the pressure ring 22 is provided with a limiting groove 221 at the position corresponding to the limiting block 2135.

[0060] In this design, the pressure ring 22 axially limits the assembly 213, and the circumferential limit of the assembly 213 can be achieved through the cooperation of the limiting block 2135 and the limiting groove 221, so as to avoid relative rotation between the pressure ring 22 and the assembly 213 and ensure the stability of the structure.

[0061] In some embodiments, there are multiple limiting blocks 2135 and multiple limiting grooves 221, and the multiple limiting blocks 2135 and multiple limiting grooves 221 are evenly arranged, with each limiting block 2135 corresponding to one limiting groove 221.

[0062] In some implementations, combined Figures 4 to 6 As shown, the pole assembly 2 also includes a protective member 23 sleeved around the outer periphery of the pressure ring 22, with one end of the protective member 23 facing the plate body 1 supported on the side of the plate body 1. Combined with... Figure 11 and Figure 12 As shown, a limiting hole 222 is provided on the pressure ring 22, and a limiting protrusion 231 is provided on the inner side of the protective member 23 at a position corresponding to the limiting hole 222. The protective member 23 is made of plastic and is assembled to the outer periphery of the pressure ring 22 by injection molding.

[0063] In this design, the limiting hole 222 and the limiting protrusion 231 can increase the circumferential limiting effect between the pressure ring 22 and the protective member 23, avoid relative rotation between the protective member 23 and the pressure ring 22, and ensure the stability of the structure.

[0064] In some embodiments, an annular gap is formed between the pressure ring 22 and the kit 213, and an annular insert 232 is provided at the position corresponding to the annular gap of the protective member 23. The annular insert 232 can be inserted into the annular gap to ensure the compactness and sealing effect of the pole assembly 2.

[0065] In some embodiments, there are multiple limiting holes 222 and multiple limiting protrusions 231, and the multiple limiting holes 222 and multiple limiting protrusions 231 are evenly arranged, with each limiting hole 222 corresponding to one limiting protrusion 231.

[0066] In some embodiments, a sealing element 3 is provided between the terminal 21 and the plate 1. By providing the sealing element 3, the sealing effect between the terminal 21 and the plate 1 can be increased, ensuring the safety of battery use. The sealing element 3 can be a rubber sealing ring or the like, and can be selected according to actual needs.

[0067] In some embodiments, an insulating plate 4 is provided on the side of the plate body 1 facing away from the electrode post 21, and a snap-fit ​​hole is provided on the same side. The insulating plate 4 has a snap fastener that matches the snap-fit ​​hole. By providing the insulating plate 4, the battery cell is separated from the plate body 1, ensuring the battery cell's performance. The snap-fit ​​connection between the snap-fit ​​hole and the snap fastener increases the accuracy of the installation and positioning of the insulating plate 4 and the plate body 1, preventing misalignment. After the plate body 1 and the insulating plate 4 are positioned, they can be fixed together by welding to ensure a strong connection.

[0068] In some implementations, such as Figure 4 As shown, when the electrode post 21 is used as the positive electrode of the battery, the electrode post body 212 of the electrode post 21 is made of aluminum, such as... Figure 5 As shown, when the electrode post 21 is used as the negative electrode of the battery, the electrode post body 212 of the electrode post 21 is made of aluminum-copper material, wherein the copper block is set on the side of the electrode post body 212 close to the plate 1, and the aluminum block is set on the side of the electrode post body 212 away from the plate 1.

[0069] When the terminal 21 is used as the negative electrode of the battery, the diameter of the aluminum block at the contact point with the copper block is larger than the diameter of the aluminum block at the non-contact point with the copper block, so that the outer periphery of the copper block and the aluminum block forms a stepped structure, allowing the kit 213 to be fitted onto the outer periphery of the aluminum block and the copper block, pressing the copper block and the aluminum block against the plate 1, thereby wrapping the aluminum block and the copper block, reducing the risk of the terminal 21 disintegrating, and avoiding battery sealing failure, which could lead to a short circuit and fire, causing a safety accident.

[0070] In some embodiments, the plate 1 of this application is also provided with common equipment such as an explosion-proof valve injection hole, but its specific structure and design location are not described in detail here.

[0071] The present invention also provides a battery, comprising a bottom shell with an open top, a battery cell disposed inside the bottom shell, and the aforementioned top cover plate, wherein the top cover plate is disposed at the open end of the bottom shell, and the battery cell is connected to an electrode post 21 on the top cover plate. The top cover plate here includes all the technical features of the aforementioned top cover plate.

[0072] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0073] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments described herein, but is to be accorded the widest scope consistent with the principles and novel features of the invention described herein.

Claims

1. A head cover plate characterized by, The utility model relates to a plate body (1) and two pole post assemblies (2) arranged on the plate body (1), the plate body (1) is equipped with pole post hole (11), the pole post assembly (2) includes: Pole post body (21) is arranged on the plate body (1) and is located on one side of the pole post hole (11), and the outer periphery of the pole post body (21) is equipped with step structure (211), and Compression ring (22) is sleeved on the outer periphery of the step structure (211) of the pole post body (21), and one end of the compression ring (22) towards the plate body (1) is fixedly connected with the plate body (1).

2. The header panel of claim 1, wherein, The pole post body (21) includes a pole post body (212) and a sleeve (213) sleeved on the outer periphery of the pole post body (212), and the outer periphery of the sleeve (213) is provided with the step structure (211).

3. The head cover plate of claim 2, wherein, The pole post body (212) includes coaxially arranged first cylinder (2121) and second cylinder (2122), the diameter of the second cylinder (2122) is greater than that of the first cylinder (2121), the second cylinder (2122) is arranged on the side of the plate body (1), and the sleeve (213) is sleeved on the outer periphery of the step surface of the first cylinder (2121) and the second cylinder (2122).

4. The head cover plate of claim 3, wherein The outer periphery of the side of the second cylinder (2122) towards the first cylinder (2121) is provided with a torque enhancing port (21221), and the sleeve (213) is provided with a torque enhancing block (2131) at a position corresponding to the torque enhancing port (21221).

5. The head cover plate of claim 3, wherein The outer periphery of the side of the second cylinder (2122) away from the first cylinder (2121) is provided with a socket (21222), and the sleeve (213) is provided with an insertion block (2132) at a position corresponding to the socket (21222).

6. The header panel of claim 3, wherein, The sleeve (213) includes a first sleeve body (2133) and a second sleeve body (2134), the diameter of the second sleeve body (2134) is greater than that of the first sleeve body (2133), wherein the first sleeve body (2133) is sleeved on the outer periphery of the first cylinder (2121), the second sleeve body (2134) is sleeved on the outer periphery of the second cylinder (2122), the outer periphery of the first sleeve body (2133) and the second sleeve body (2134) forms the step structure (211), one end of the compression ring (22) is weldedly connected with the plate body (1), and the other end of the compression ring (22) is pressed on the end face of the second sleeve body (2134).

7. The header panel of claim 2, wherein, The outer periphery of the sleeve (213) is provided with a limiting block (2135), and the compression ring (22) is provided with a limiting groove (221) at a position corresponding to the limiting block (2135).

8. The header panel of claim 1, wherein, The pole post assembly (2) further comprises a protection member (23) sleeved on the outer periphery of the compression ring (22), one end of the protection member (23) facing the plate body (1) is supported on the side surface of the plate body (1), a limiting hole (222) is formed on the compression ring (22), and a limiting protrusion (231) is arranged on the inner side of the protection member (23) at a position corresponding to the limiting hole (222).

9. The header panel of claim 1, wherein, A sealing member (3) is arranged between the pole post body (21) and the plate body (1); And / or, an insulating plate (4) is arranged on the side of the plate body (1) away from the pole post body (21), a buckle hole is arranged on the side of the plate body (1) away from the pole post body (21), and a reverse buckle matched with the buckle hole is arranged on the insulating plate (4).

10. A battery, characterized by The battery cell comprises a bottom shell with an open top, an electric core arranged inside the bottom shell, and a top cover plate as claimed in any one of claims 1 to 9, the top cover plate is arranged at the open end of the bottom shell, and the electric core is connected with the pole post body (21) on the top cover plate.

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