Cover plate assembly and cylindrical lithium battery

Abstract

The utility model provides a cover plate assembly and a cylindrical lithium battery. The cover plate assembly comprises a cover plate, an upper plastic part and a pole. The upper plastic part comprises a body and a flange. A first boss and a first groove which are adjacent to each other are alternately arranged on the top face of the cover plate along the edge of an opening of the first mounting hole, and a second boss and a second groove which are adjacent to each other are alternately arranged on the bottom face of the body along the edge of the outer wall face of the flange. The first boss, the first groove, the second boss and the second groove are jointly combined to form an anti-torsion structure, and due to the limiting effect of the anti-torsion structure, the upper plastic part and the cover plate cannot rotate relatively, so that the lithium battery comprising the cover plate assembly can be prevented from being damaged after being used for a long time or under severe working conditions, and the service life of the lithium battery is prolonged. The upper plastic part can be prevented from twisting relative to the cover plate, so that the pole column can be prevented from twisting, and the reliability of the lithium battery can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of lithium-ion batteries, and in particular, to a cover assembly and a cylindrical lithium battery. Background Art

[0002] In the related art, a pole riveting structure can be constructed on the top cover as the positive electrode of a cylindrical lithium battery. The pole riveting structure generally includes a pole made of a metal material and an upper plastic part made of a plastic material. Among them, the sealing and fixing of the pole are achieved through the riveting force between the flanging of the pole and the upper plastic part. However, since the hardness and strength of the upper plastic part are much smaller than those of the pole, during long-term use, if the pole shakes frequently, the upper plastic part will be deformed, and then the upper plastic part will become loose and twist. If the pole twists together with the upper plastic part, the lithium battery will fail. In particular, for lithium batteries used in harsh working conditions such as power tools, this problem is particularly prominent. Summary of the Utility Model

[0003] Embodiments of the present application provide a cover assembly and a cylindrical lithium battery to at least solve the technical problem that the upper plastic part of the existing cover assembly is prone to twisting during long-term use and under harsh working conditions.

[0004] A cover assembly provided by an embodiment of the first aspect of the present application includes:

[0005] A cover plate, provided with a through first mounting hole, and along the edge of the opening on the top surface of the cover plate around the first mounting hole, a first boss and a first groove adjacent to each other are alternately arranged;

[0006] An upper plastic part, including a body and a flange provided at the bottom of the body, the body abuts against the top surface of the cover plate, the flange passes through the first mounting hole, and along the outer peripheral edge of the flange, a second boss and a second groove adjacent to each other are alternately arranged;

[0007] Wherein, each of the first bosses is nested in each of the second grooves in a one-to-one correspondence, and each of the second bosses is nested in each of the first grooves in a one-to-one correspondence to limit the rotation of the upper plastic part relative to the cover plate.

[0008] The cover assembly according to the embodiment of the present application has at least the following beneficial effects:

[0009] In the cover plate assembly according to the embodiment of the present application, the pole post rivets the upper plastic part on the top surface of the cover plate through a riveting process, and a torsion prevention structure is formed by the first boss, the first groove formed on the cover plate and the second boss, the second groove formed on the upper plastic part. Due to the limiting effect of the torsion prevention structure, relative rotation will not occur between the upper plastic part and the cover plate. Thus, for the lithium battery including the above cover plate assembly, after long-term use or use under harsh working conditions, the upper plastic part can be prevented from twisting relative to the cover plate, and further the pole post can be prevented from twisting, thereby improving the reliability of the lithium battery.

[0010] In a possible implementation manner, a chamfering portion is provided between the top surface of the first boss and the hole wall of the first mounting hole. The chamfering portion includes a first chamfering portion and a second chamfering portion that are connected and have different inclination angles. By providing the first chamfering portion and the second chamfering portion with different inclination angles, the upper plastic part can be continuously positioned and guided by the first chamfering portion and the second chamfering portion during assembly, and can be quickly and accurately connected to the cover plate.

[0011] In a possible implementation manner, the thickness of the cover plate at the position where the first boss is provided is H, the vertical height of the first chamfering portion in the thickness direction of the cover plate is H1, and the vertical height of the second chamfering portion in the thickness direction of the cover plate is H2, satisfying: H1 / H = 10% - 30%, H2 / H = 20% - 40%. By reasonably setting the vertical heights of the first chamfering portion and the second chamfering portion, while ensuring that the first chamfering portion and the second chamfering portion can effectively position and guide the upper plastic part, it is ensured that the hole wall of the first mounting hole has sufficient dimensions, so that the upper plastic part fits well with the hole wall to ensure sufficient torsional force effect, thereby improving the reliability of the connection between the upper plastic part and the cover plate.

[0012] In a possible implementation manner, the bottom edge of the second chamfering portion is coplanar with the top surface of the first groove. Thus, the hole wall in the first mounting hole for fitting with the upper plastic extends from the top surface of the first groove to the bottom surface of the cover plate, and the height and shape of the hole wall in the circumferential direction are consistent, and can be well assembled and fitted with the upper plastic part.

[0013] In a possible implementation manner, the included angle between the first chamfering portion and the hole wall is α, satisfying 35° ≤ α ≤ 60°, and the included angle between the second chamfering portion and the hole wall is β, satisfying: 10° ≤ β ≤ 30°. By reasonably designing the included angles between the first chamfering portion and the second chamfering portion and the hole wall, the positioning and guiding effects on the upper plastic part can be effectively achieved, and the assembly efficiency can be improved.

[0014] In a possible implementation manner, both the first boss and the first groove are arc-shaped. A plurality of the first bosses and a plurality of the first grooves are alternately connected around the first mounting hole to form an annular structure. The central angle of the first boss is R1, and the central angle of the first groove is R2, satisfying: R2 < R1. For the anti-torsion structure, it mainly realizes anti-torsion through the cooperation of the first boss of the cover plate and the second groove of the upper plastic part. The second protrusion of the upper plastic part plays an auxiliary anti-torsion role. The material of the cover plate is metal, and the material of the upper plastic part is plastic. The strength of the metal material is much greater than that of the plastic material. Therefore, by designing the central angle of the first groove R2 to be less than the central angle of the first boss R1, the structural strength of the first boss can be significantly increased, and the anti-torsion effect can be improved.

[0015] In a possible implementation manner, R2 / R1 = 60% - 80%. Through the reasonable design of the central angles of the first boss and the first groove, it is ensured that both the first boss and the second boss have good strength, and the anti-torsion strength is improved.

[0016] In a possible implementation manner, the thickness of the cover plate is H0, and the depth of the first groove is H3, satisfying: H3 / H0 = 30% - 50%. By reasonably designing the depth of the first groove, while ensuring the anti-torsion effect, the structural strength of the cover plate at the first mounting hole can also be ensured.

[0017] In a possible implementation manner, the thickness of the cover plate is H0, and the height of the first boss exceeding the top surface of the first groove is H4, satisfying: H4 / H0 = 70% - 95%. By reasonably designing the height of the first boss, while ensuring the anti-torsion effect, the structural strength of the upper plastic part can also be ensured.

[0018] The second aspect embodiment of the present application provides a cylindrical lithium battery, which includes the cover plate assembly of the first aspect embodiment described above.

[0019] The cylindrical lithium battery according to the embodiment of the present application has at least the following beneficial effects:

[0020] For the cylindrical lithium battery of the embodiment of the present application, when it is used for a long time or under harsh working conditions, the upper plastic part is not easily twisted relative to the cover plate, ensuring the connection stability between them, thereby further ensuring the stability of the pole column flanging riveting, and further enabling the pole column not to be easily twisted, having the characteristics of high reliability. Description of the Drawings

[0021] To more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments of the present application. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0022] Figure 1 It is a schematic cross-sectional view of a cover plate assembly provided by an embodiment of the present application;

[0023] Figure 2 It is a schematic cross-sectional view of a cover plate assembly provided by an embodiment of the present application from another angle and with a partial enlargement;

[0024] Figure 3 It is a schematic cross-sectional view of the cover plate in a cover plate assembly provided by an embodiment of the present application;

[0025] Figure 4 is Figure 3 a partial schematic view of location A in

[0026] Figure 5 is Figure 3 a top view schematic of the cover plate in

[0027] Figure 6 It is a structural schematic view of an upper plastic part in a cover plate assembly provided by an embodiment of the present application.

[0028] Reference numerals:

[0029] 10 - cover plate, 11 - first mounting hole, 12 - first boss, 121 - chamfered part, 1211 - first chamfer, 1212 - second chamfer, 13 - first groove, 14 - hole wall;

[0030] 20 - upper plastic part, 21 - body, 211 - second boss, 212 - second groove, 22 - flange, 23 - second mounting hole;

[0031] 30 - pole column, 31 - flanging;

[0032] 40 - housing;

[0033] 50 - lower plastic part;

[0034] 60 - sealing ring. Detailed implementation manners

[0035] Embodiments of the present embodiment will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary and are only used to explain the present embodiment, and should not be construed as a limitation of the present embodiment.

[0036] In the description of the present embodiment, it should be understood that with regard to the orientation description, such as the orientation or positional relationship indicated by up, down, front, back, left, right, etc., is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present embodiment and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present embodiment.

[0037] In the description of the present embodiment, the meaning of several is one or more, the meaning of multiple is two or more, greater than, less than, exceeding, etc. are understood as not including the present number, and above, below, within, etc. are understood as including the present number. If the first and second are described only for the purpose of distinguishing technical features, they should not be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or the sequence relationship of the indicated technical features.

[0038] In the description of the present embodiment, unless otherwise clearly defined, words such as setting, installing, connecting, etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above words in the present embodiment in combination with the specific content of the technical solution.

[0039] The following will be combined with Figures 1 to 6 to describe in detail the cover assembly of the embodiments of the present application.

[0040] As Figure 1 and Figure 2 shown, the cover assembly includes a cover 10, an upper plastic part 20, and a terminal 30. This cover assembly can be used for various types of lithium batteries, such as cylindrical lithium batteries, to form the positive or negative electrode of the lithium battery. In the cover assembly of the embodiments of the present application, by constructing a first boss 12 and a first groove 13 on the cover 10, and a second boss 211 and a second groove 212 on the upper plastic part 20, after the two are assembled, the first boss 12, the first groove 13, the second boss 211, and the second groove 212 jointly form an anti-torsion structure, thereby effectively preventing the upper plastic part 20 from rotating relative to the cover 10 to improve the reliability of the lithium battery.

[0041] The cover assembly includes a cover 10, the material of which is metal. It can be understood that the cover 10 is the installation base for components such as the upper plastic part 20 and the terminal 30, and is connected to the housing of the lithium battery when the cover assembly is assembled into the lithium battery. AsFigure 1 and Figure 3 As shown, taking the application of the cover plate assembly to a cylindrical lithium battery as an example, the cylindrical lithium battery includes a cylindrical shell 40, and the cover plate 10 is located on the top of the shell 40 as the top cover of the cylindrical lithium battery, and the cover plate 10 is integrally formed with the shell 40. In this way, the process of separately welding the cover plate 10 on the shell 40 can be omitted, which can save processes and costs. Of course, it is not limited to this. The cover plate 10 can also be an independent component such as a metal sheet, which is subsequently connected to the shell 40 through a welding process. Further, the cover plate 10 is the top cover of the cylindrical lithium battery, and therefore, the cover plate 10 is circular as a whole, but it is not limited to this. For example, the shape of the cover plate 10 can also be rectangular for square lithium batteries.

[0042] like Figure 3 As shown, it can be understood that the cover plate 10 has a top surface and a bottom surface relative to each other. For a lithium battery, the top surface of the cover plate 10 is located outside the lithium battery, and the bottom surface of the cover plate 10 is located inside the lithium battery. The cover plate 10 is provided with a first mounting hole 11 (refer to Figures 3 to 5 ), that is, the first mounting hole 11 passes through the cover plate 10 along the thickness direction (the up and down direction in the figure), so that the first mounting hole 11 connects the top surface and the bottom surface of the cover plate 10, and the first mounting hole 11 is used for the upper plastic part 20 to pass through it, so as to achieve insulation isolation of the pole 30 passing through the upper plastic part 20.

[0043] It is understandable that if Figure 3 As shown, along the edge of the opening of the first mounting hole 11 on one side of the top surface of the cover plate 10, first bosses 12 and first grooves 13 adjacent to each other are alternately arranged. It can be understood that the first boss 12 and the first groove 13 are constructed at the edge of the opening of the first mounting hole 11 on the top surface of the cover plate 10, so that when the upper plastic part 20 is operated to perform assembly movement from top to bottom in a direction close to the top surface of the cover plate 10, the first boss 12 and the first groove 13 can perform an assembly movement of being nested with the second groove 212 and the second boss 211 constructed on the upper plastic part 20 to be described below, and finally combined into an anti-twist structure.

[0044] It can be understood that the alternating arrangement described here means that along the circumferential direction of the edge surrounding the opening of the first mounting hole 11, the first bosses 12 and the first grooves 13 are arranged in an alternating manner, that is, a first groove 13 is arranged between two first bosses 12, and correspondingly, a first boss 12 is arranged between two first grooves 13. In this way, firstly, in the circumferential direction surrounding the first mounting hole 11, staggered first bosses 12 and first grooves 13 are formed, so that the anti-twist structure formed after being nested with the second groove 212 and the second boss 211 is evenly distributed in the circumferential range of 360 degrees, the force is relatively balanced, and the anti-twist structure is safe and reliable.

[0045] It can also be understood that the adjacency described herein means that there is no isolation between the first boss 12 and the first groove 13, that is, the space defined between the two first bosses 12 is the first groove 13. Correspondingly, the structure in which the two first grooves 13 are spaced apart is the first boss 12.

[0046] As Figure 5 shown, in combination with Figure 6 , it can be understood that the anti-torsion structure described in this embodiment is composed of the first boss 12 and the first groove 13 formed on the cover plate 10 and the second boss 211 and the second groove 212 formed on the upper plastic part 20, which are jointly connected and matched. Therefore, the shapes, sizes, and numbers of the first boss 12 and the second groove 212 are matched, and the shapes, sizes, and numbers of the first groove 13 and the second boss 211 are matched. Specifically, the height of the first boss 12 and the depth of the second groove 212 are matched so that the first boss 12 can be completely nested in the second groove 212. Correspondingly, the height of the second boss 211 and the depth of the first groove 13 are matched so that the second boss 211 can be completely nested in the first groove 13, thereby enabling the bottom surface of the upper plastic part 20 to be well attached to the top surface of the cover plate 10. Taking the numbers of the first boss 12, the first groove 13, the second boss 211, and the second groove 212 as an example, for example, the numbers of the first boss 12 and the first groove 13 are both four. Correspondingly, the numbers of the second boss 211 and the second groove 212 on the upper plastic part 20 that cooperate with them are also four.

[0047] It can be understood that when the upper plastic part 20 is correctly installed on the cover plate 10 and passes through the first mounting hole 11, each first boss 12 is nested in each second groove 212 one by one, and each second boss 211 is nested in each first groove 13 one by one. The first boss 12, the first groove 13, the second boss 211, and the second groove 212 jointly form an anti-torsion structure. Due to the limiting effect of the anti-torsion structure, there is no relative rotation between the upper plastic part 20 and the cover plate 10.

[0048] As Figure 1 and Figure 2 shown, the upper plastic part 20 includes a body 21 and a flange 22 provided at the bottom of the body 21. After the upper plastic part 20 and the cover plate 10 are correctly assembled, the flange 22 passes through the first mounting hole 11, and the outer wall surface of the flange 22 is well attached to the hole wall 14 of the first mounting hole 11, thereby isolating the pole 30 from the cover plate 10. In order to facilitate the assembly of the upper plastic part 20, in some embodiments, such as Figure 2 , Figure 3 and Figure 4As shown, a chamfer portion 121 is provided between the top surface of the first boss 12 and the hole wall 14 of the first mounting hole 11. The chamfer portion 121 includes a first chamfer portion 1211 and a second chamfer portion 1212 that are connected and have different inclination angles. It can be understood that in this way, the top surface of the first boss 12, the first chamfer portion 1211, the second chamfer portion 1212, and the hole wall 14 are sequentially and smoothly connected. By providing the first chamfer portion 1211 and the second chamfer portion 1212 with different inclination angles, when the plastic part 20 moves in the vertical direction from top to bottom in the direction close to the top surface of the cover plate 10 during assembly, the flange 22 of the upper plastic part 20 can be continuously positioned and guided by the first chamfer portion 1211 and the second chamfer portion 1212, and can be quickly and accurately inserted into the first mounting hole 11, and its outer wall surface fits well with the hole wall 14 of the first mounting hole 11.

[0049] Furthermore, as Figure 4 shown, the thickness of the cover plate 10 at the location where the first boss 12 is provided is H, the vertical height (height in the up-and-down direction) of the first chamfer portion 1211 in the thickness direction of the cover plate 10 is H1, and the vertical height of the second chamfer portion 1212 in the thickness direction of the cover plate 10 is H2, satisfying: H1 / H = 10% - 30%, H2 / H = 20% - 40%. Since the thickness of the cover plate 10 is usually relatively thin, therefore, by reasonably setting the vertical heights of the first chamfer portion 1211 and the second chamfer portion 1212, while ensuring that the first chamfer portion 1211 and the second chamfer portion 1212 can effectively position and guide the flange 22 of the upper plastic part 20, it is ensured that the hole wall 14 of the first mounting hole 11 has sufficient dimensions. Thus, the hole wall 14 of the first mounting hole 11 is not less than 30% of H. Thereby, it can be ensured that there is good fitting between the upper plastic part 20 and the hole wall 14, and the reliability of the assembly between the upper plastic part 20 and the cover plate 10 is improved.

[0050] As Figure 4 shown, in some embodiments, the bottom edge of the second chamfer portion 1212 is coplanar with the top surface of the first groove 13. Thus, the hole wall 14 in the first mounting hole 11 for fitting with the upper plastic extends from the top surface of the first groove 13 to the bottom surface of the cover plate 10, and the height and shape of the hole wall 14 in the circumferential direction are the same, that is, the hole wall 14 is an inner circular surface with a certain height, so that it can be well assembled and fitted with the upper plastic part 20.

[0051] As Figure 4As shown, in some embodiments, the included angle between the first chamfered portion 1211 and the hole wall 14 is α, satisfying 35° ≤ α ≤ 60°, and the included angle between the second chamfered portion 1212 and the hole wall 14 is β, satisfying 10° ≤ β ≤ 30°. By reasonably designing the included angles between the first chamfered portion 1211 and the second chamfered portion 1212 and the hole wall 14, the positioning and guiding effects on the upper plastic part 20 can be effectively achieved, and the assembly efficiency can be improved. Moreover, the first chamfered portion 1211 and the second chamfered portion 1212 are also easy to be processed and formed within this angle range.

[0052] As Figure 4 shown, in some embodiments, the thickness of the cover plate 10 is H0, and the depth of the first groove 13 is H3, satisfying H3 / H0 = 30% - 50%. At the same time, the height of the first boss 12 exceeding the top surface of the first groove 13 is H4, satisfying H4 / H0 = 70% - 95%. By reasonably designing the height of the first boss 12 and the depth of the first groove 13, while ensuring the anti-torsion effect, the structural strength of the cover plate 10 at the first mounting hole 11 can also be ensured.

[0053] As Figure 5 shown, in some embodiments, both the first boss 12 and the first groove 13 are arc-shaped. A plurality of first bosses 12 and a plurality of first grooves 13 are alternately connected around the first mounting hole 11 to form an annular structure. The central angle of the first boss 12 is R1, and the central angle of the first groove 13 is R2, satisfying R2 < R1. It can be understood that since the central angle of the first groove 13 is R2 which is less than the central angle of the first boss 12 which is R1, that is, the arc length of the first groove 13 is shorter than the arc length of the first boss 12. It can also be understood that since the first boss 12 cooperates with the second groove 212, and the first groove 13 cooperates with the second boss 211, for the anti-torsion structure, it mainly realizes anti-torsion through the cooperation between the first boss 12 of the cover plate 10 and the second groove 212 of the upper plastic part 20, and the second protrusion 211 of the upper plastic part 20 plays an auxiliary anti-torsion role. And the material of the cover plate 10 is metal, and the material of the upper plastic part 20 is plastic. The strength of the metal material is much greater than that of the plastic material. Therefore, by designing the central angle of the first groove 13 as R2 to be less than the central angle of the first boss 12 as R1, the structural strength of the first boss 12 can be significantly increased, and the anti-torsion effect can be improved. As mentioned above, since the shapes, sizes and numbers of the first boss 12 and the second groove 212 match, and the shapes, sizes and numbers of the first groove 13 and the second boss 211 match, in this case, the central angle sizes of the second boss 211 and the second groove 212 formed on the upper plastic part 20 are in an opposite relationship, which will not be elaborated here.

[0054] Further, in some embodiments, R2 / R1 = 60% - 80%. Through the reasonable design of the central angles of the first boss 12 and the first groove 13, it is ensured that both the first boss 12 and the second boss 211 have good strength, guaranteeing the safety and reliability of the anti-torsion structure.

[0055] It can be understood that the cover plate assembly includes an upper plastic part 20, and the upper plastic part 20 functions to insulate and isolate the pole column 30 from the cover plate 10. In this embodiment, the material of the upper plastic part 20 is plastic, and it is an independent component formed by, for example, an injection molding process. It is connected to the cover plate 10 through a certain assembly movement and is pressed against the top surface of the cover plate 10 by the riveting force generated by the flanging 31 at the top of the pole column 30, and finally forms a cover plate assembly together with the cover plate 10, the pole column 30, etc.

[0056] As Figure 6 shown, and in combination with Figure 1 and Figure 2 , in some embodiments, the upper plastic part 20 includes a body 21 and a flange 22 provided at the bottom of the body 21. The upper plastic part 20 is provided with a second mounting hole 23 penetrating through the body 21 and the flange 22, that is, the second mounting hole 23 penetrates through the upper plastic part 20 in the thickness direction (the up and down direction in the figure), so that the second mounting hole 23 communicates with the top surface of the body 21 and the bottom surface of the flange 22. This second mounting hole 23 is for the pole column 30 to pass through it to achieve the insulation isolation between the cover plate 10 and the pole column 30.

[0057] Specifically, the outer contour dimension of the body 21 is larger than the diameter of the first mounting hole 11, while the outer contour dimension of the flange 22 is adapted to the inner diameter of the first mounting hole 11. Thus, when the upper plastic part 20 is operated to move in the direction from top to bottom towards the top surface of the cover plate 10 for assembly, the flange 22 can penetrate into the first mounting hole 11, and its outer surface can be in good fit with the inner wall surface of the first mounting hole 11, while the body 21 can be limited by the top surface of the cover plate 10, thereby preventing the whole upper plastic part 20 from falling into and passing through the first mounting hole 11. It can be understood that in the assembled cover plate assembly, the body 21 is pressed against the top surface of the cover plate 10 by the riveting force of the pole column 30.

[0058] Furthermore, it can be understood that along the outer peripheral edge of the flange 22 for one circle, second bosses 211 and second grooves 212 adjacent to each other are alternately arranged. It can be understood that along the outer peripheral edge of the flange 22 for one circle, second bosses 211 and second grooves 212 are constructed on the bottom surface of the body 21, so that when the upper plastic part 20 is operated to move in the direction from top to bottom towards the top surface of the cover plate 10 for assembly, the second bosses 211 and the second grooves 212 can make a nested assembly movement with the first grooves 13 and the first bosses 12 constructed on the cover plate 10, and finally form an anti-torsion structure.

[0059] It can be understood that the alternating arrangement described herein means that along the circumferential direction around the outer wall surface of the circumferential flange 22, the second bosses 211 and the second grooves 212 are arranged in an alternating and staggered manner, that is, there is a second groove 212 between two second bosses 211, and correspondingly, there is a second boss 211 between two second grooves 212. In this way, first, in the circumferential direction around the outer wall surface of the circumferential flange 22, the second bosses 211 and the second grooves 212 are formed in an alternating pattern, so that the anti-torsion structure formed after being nested with the first groove 13 and the first boss 12 is evenly distributed in the 360-degree circumferential range, the force is relatively balanced, and the anti-torsion structure is safe and reliable.

[0060] It can also be understood that the adjacency described herein means that there is no isolation between the second boss 211 and the second groove 212, that is, the space defined between two second bosses 211 is the second groove 212, and correspondingly, the structure separating two second grooves 212 is the second boss 211.

[0061] As Figure 6 shown, and in combination with Figure 5 , it can be understood that the anti-torsion structure described in this embodiment is composed of the first boss 12 and the first groove 13 constructed on the cover plate 10 and the second boss 211 and the second groove 212 constructed on the upper plastic part 20, which are jointly connected and cooperated. Therefore, the shapes, sizes and numbers of the first boss 12 and the second groove 212 are matched, and the shapes, sizes and numbers of the first groove 13 and the second boss 211 are matched. Specifically, the height of the first boss 12 and the depth of the second groove 212 are matched, so that the first boss 12 can be completely nested in the second groove 212. Correspondingly, the height of the second boss 211 and the depth of the first groove 13 are matched, so that the second boss 211 can be completely nested in the first groove 13, and further, the bottom surface of the upper plastic part 20 can be well attached to the top surface of the cover plate 10. Taking the numbers of the first boss 12, the first groove 13, the second boss 211 and the second groove 212 as an example, for example, the numbers of the first boss 12 and the first groove 13 are both four, and correspondingly, the numbers of the second boss 211 and the second groove 212 on the upper plastic part 20 that cooperate with them are also four.

[0062] It can be understood that the cover plate assembly includes a terminal post 30. When assembled into a lithium battery, the terminal post 30 is electrically connected to the internal wound core electrode group of the lithium battery to serve as the electrical contact point of the lithium battery for connecting an external electrical device to the lithium battery. It can be understood that the material of the terminal post 30 is a metal such as aluminum, which has good electrical conductivity and is also easy to rivet the upper plastic part 20 on the top surface of the cover plate 10 through the riveting process. It can be understood that through the riveting process, a flanging 31 is formed on the top surface of the terminal post 30, and the flanging 31 presses on the top of the upper plastic part 20.

[0063] Of course, it can be understood that in addition to the cover plate 10, the upper plastic part 20, and the terminal post 30 mentioned above, the cover plate assembly also includes components such as a lower plastic part 50 and a sealing ring 60 located on one side of the bottom surface of the cover plate 10. Since these components are irrelevant to the purpose of this application, they will not be introduced in this application.

[0064] The embodiment of the present application also provides a cylindrical lithium battery, which includes the cover plate assembly of the above embodiment. Since the cylindrical lithium battery of the embodiment of the present application has the cover plate assembly of the above embodiment, when used for a long time or under harsh working conditions, the upper plastic part is not easily twisted relative to the cover plate, ensuring the connection stability between them. Thus, it further ensures the stability of the riveting of the terminal post flanging, and further enables the terminal post not to be easily twisted, having the characteristic of high reliability.

[0065] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of this implementation. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0066] Although the embodiments of this implementation have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principle and purpose of this implementation. The scope of this implementation is defined by the claims and their equivalents.

Claims

1. A cover plate assembly, characterized in that, Comprising: A cover plate (10) is provided with a through first mounting hole (11). Along the edge of the opening on the top surface of the cover plate (10) along the first mounting hole (11), a first boss (12) and a first groove (13) adjacent to each other are alternately arranged. The space defined between two of the first bosses (12) is the first groove (13), and the structure where two of the first grooves (13) are spaced apart is the first boss (12). A chamfer portion (121) is provided between the top surface of the first boss (12) and the hole wall (14) of the first mounting hole (11). The chamfer portion (121) includes a first chamfer portion (1211) and a second chamfer portion (1212) that are connected and have different inclination angles. The thickness of the cover plate (10) at the location where the first boss (12) is provided is H. The vertical height of the first chamfer portion (1211) in the thickness direction of the cover plate (10) is H1, and the vertical height of the second chamfer portion (1212) in the thickness direction of the cover plate (10) is H2, satisfying: H1 / H = 10% - 30%, H2 / H = 20% - 40%; An upper plastic part (20) includes a body (21) and a flange (22) provided at the bottom of the body (21). The body (21) abuts against the top surface of the cover plate (10). The flange (22) passes through the first mounting hole (11). Along the outer peripheral edge of the flange (22) in a circle, a second boss (211) and a second groove (212) adjacent to each other are alternately arranged. The space defined between two of the second bosses (211) is the second groove (212), and the structure where two of the second grooves (212) are spaced apart is the second boss (211); Wherein, each of the first bosses (12) is nested in each of the second grooves (212) one by one, and each of the second bosses (211) is nested in each of the first grooves (13) one by one to limit the rotation of the upper plastic part (20) relative to the cover plate (10).

2. The cover plate assembly according to claim 1, wherein The bottom edge of the second chamfer portion (1212) is coplanar with the top surface of the first groove (13).

3. The cover plate assembly according to claim 1 or 2, characterized in that, The included angle between the first chamfer portion (1211) and the hole wall (14) is α, satisfying 35° ≤ α ≤ 60°. The included angle between the second chamfer portion (1212) and the hole wall (14) is β, satisfying: 10° ≤ β ≤ 30°.

4. The cover plate assembly according to claim 1 or 2, characterized in that Both the first boss (12) and the first groove (13) are arc-shaped. A plurality of the first bosses (12) and a plurality of the first grooves (13) are alternately connected around the first mounting hole (11) to form an annular structure. The central angle of the first boss (12) is R1, and the central angle of the first groove (13) is R2, satisfying: R2 < R1.

5. The cover plate assembly according to claim 4, wherein R2 / R1 = 60% - 80%.

6. The cover plate assembly according to claim 1 or 2, characterized in that, The thickness of the cover plate (10) is H0, and the depth of the first groove (13) is H3, satisfying: H3 / H0 = 30% - 50%.

7. The cover plate assembly according to claim 1 or 2, characterized in that, The thickness of the cover plate (10) is H0, and the height by which the first boss (12) exceeds the top surface of the first groove (13) is H4, satisfying: H4 / H0 = 70% to 95%.

8. A cylindrical lithium battery, characterized in that, Comprising a cover plate assembly according to any one of claims 1 to 7.

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