Battery cover plate assembly and battery

Abstract

The invention relates to the technical field of batteries, and particularly discloses a battery cover plate assembly and a battery, and the battery cover plate assembly comprises a connecting block and a pole. One end of the pole penetrates through the connecting block and then is riveted with the first step surface of the first sinking table, the end, riveted with the first step surface, of the pole expands towards the periphery to form a riveting part, a seam is formed between the peripheral side wall of the riveting part and the first side wall of the first sinking table, and the seam of the riveting part and the first side wall of the first sinking table is welded to form a welding part. Wherein the diameter of the riveting part is d1, the distance between the center line of the welding part and the peripheral side wall of the riveting part is n, and the relation between n and d1 meets the condition that n / d1 is larger than or equal to 0.0125 and smaller than or equal to 0.025. By improving the welding structure between the pole and the connecting block, the connecting strength between the pole and the connecting block is relatively high, the over-current capability is good, and the performance of the battery cover plate assembly is relatively good. The invention also provides a battery which comprises the battery cover plate assembly.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a battery cover assembly and a battery. Background Art

[0002] In lithium-ion batteries, the battery cover assembly is one of the key accessories. It is connected to the shell through the battery cover assembly to encapsulate the electrode group in the shell. At the same time, the poles on the battery cover assembly can lead out the positive and negative poles of the electrode group to connect the external circuit.

[0003] The existing battery cover assembly generally includes a connecting block, an upper plastic part, a pole, a cover body, a lower plastic part and a sealing ring, etc. The sealing ring is sleeved on the outside of the pole, and the pole passes through the lower plastic part, the cover body, the upper plastic part and the connecting block in sequence from one side of the cover body and is riveted to the connecting block. The pole is then welded to the connecting block to increase the conductivity between the two. The pole is fixedly installed on the cover body by riveting + welding. The sealing ring is located between the pole and the cover body. The gap between the pole and the cover body is sealed by the sealing ring. The upper plastic part and the lower plastic part are used to insulate and isolate the pole from the cover body.

[0004] However, since the center lines of the joint and weld between the pole and the connection block completely overlap, the melting area of ​​the pole is larger when the pole and the connection block are welded, and the mechanical properties of the weld position after welding of the pole are lower than those of the rest of the pole. The push and pull force that the pole can withstand is reduced, and when the pole is bumped or hit, it is easy to fall off the connection block, causing the risk of short circuit and battery failure. If the pole and the connection block are only riveted but not welded, the resistance between the pole and the connection block is large, the heat is serious, and the internal resistance of the battery increases. Summary of the invention

[0005] The object of the present invention is to provide a battery cover assembly and a battery, which can ensure that the connection strength between the pole and the connecting block is high and can withstand large push-pull forces when the resistance value between the pole and the connecting block is small, and the connection between the pole and the connecting block is reliable and stable.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] In one aspect, the present invention provides a battery cover assembly, comprising:

[0008] The connecting block is provided with a first mounting hole, the inner wall of the first mounting hole is provided with a first sinking platform, and the first sinking platform includes a first step surface and a first side wall;

[0009] A pole, one end of the pole passes through the first mounting hole and is riveted to the first step surface, the end of the pole riveted to the first step surface is expanded along the radial direction of the first mounting hole to form a riveted portion, the peripheral side wall of the riveted portion is welded to the first side wall to form a welding portion between the riveted portion and the first side wall, and the riveted portion, the first sink, and the welding portion are all coaxial with the first mounting hole;

[0010] The diameter of the riveted portion is d1, the diameter of the center line of the welded portion is d2, and the distance between the center line of the welded portion and the peripheral side wall of the riveted portion is n;

[0011] The relationship between n and d1 satisfies: 0.0125≤n / d1≤0.025, n=(d2-d1) / 2.

[0012] Optionally, along the radial direction of the first mounting hole, the weld width of the welding portion is w, and the value range of w is: 0.5mm≤w≤1.0mm;

[0013] And / or, along the axial direction of the first mounting hole, the penetration depth of the welding portion is h, and the value range of h is: 0.3mm≤h≤0.5mm.

[0014] Optionally, a second sinker is provided on the inner wall of the first mounting hole, and the second sinker is located near the port of the first mounting hole relative to the first sinker, and the second sinker includes a second step surface and a second side wall, and the second step surface is adjacent to the first side wall of the first sinker.

[0015] Optionally, along the axial direction of the first mounting hole, a height difference between the first step surface and the second step surface is S1, and a value range of S1 is: S1 ≥ 1.0 mm.

[0016] Optionally, along the axial direction of the first mounting hole, the height of the riveted portion is X, and the relationship between X and S1 satisfies: 0mm≤S1-X≤0.2mm.

[0017] Optionally, along the axial direction of the first mounting hole, a height difference between the second step surface and an end surface of the connecting block on a side where the second sink is provided is S2;

[0018] The value range of S2 is: 0.1mm≤S2≤1.0mm.

[0019] Optionally, along the axial direction of the first mounting hole, a distance between the top of the welding portion and the second step surface is e, and a value range of e is: 0mm≤e≤0.1mm.

[0020] Optionally, the battery cover assembly further includes a cover body, the cover body is provided with a second mounting hole, and the pole passes through the second mounting hole and the first mounting hole and is riveted to the first step surface of the first sink.

[0021] Optionally, the pole comprises a plate portion, a first column portion and a second column portion connected in sequence, the second column portion passes through the second mounting hole and the first mounting hole and is riveted to the first step surface of the first sink, the plate portion is located on a side of the cover body away from the riveted portion, the first column portion is penetrated through the second mounting hole, and the second column portion is penetrated through the first mounting hole;

[0022] There is a pre-assembly gap f between the peripheral side wall of the second column portion and the inner wall of the first mounting hole, and the value range of f is: 0.05mm≤f≤0.15mm.

[0023] On the other hand, the present invention provides a battery, comprising the battery cover assembly in any of the above schemes.

[0024] The beneficial effects of the present invention are:

[0025] The present invention provides a battery cover assembly, including a connection block and a pole. A first mounting hole is provided on the connection block, and a first sinker is provided on the inner wall of the first mounting hole. One end of the pole passes through the connection block and is riveted to the first step surface of the first sinker. One end of the pole riveted to the first step surface expands to form a riveted portion, and the peripheral side wall of the riveted portion is welded to the first side wall of the first sinker to form a welding portion. The riveted portion, the first sinker, and the welding portion are all coaxial with the first mounting hole, wherein the diameter of the riveted portion is d1, the diameter of the center line of the welding portion is d2, the distance between the center line of the welding portion and the peripheral side wall of the riveted portion is n, and the relationship between n and d1 satisfies: 0.0125≤n / d1≤0.025, n=(d2-d1) / 2. By improving the welding structure between the pole and the connection block and enlarging the diameter of the center line of the welding portion, the connection strength between the pole and the connection block is high, and the resistance value between the pole and the connection block is small, which meets the overcurrent requirements of the pole, and the performance of the battery cover assembly is good.

[0026] The present invention also provides a battery, including the above-mentioned battery cover assembly. By adopting the battery cover assembly, the resistance value between the pole and the connection block can be reduced. When the pole is connected to the external circuit, the conductive effect is good, and the heating problem of the battery cover assembly during charging and discharging is alleviated. At the same time, the connection strength between the pole and the connection block is high, and the pole and the connection block can withstand large push-pull stress. The assembly structure of the battery cover assembly is stable, reliable, and not easy to fail. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the contents of the embodiments of the present invention and these drawings without paying any creative work.

[0028] Figure 1 An exploded view of a battery cover assembly provided in an embodiment of the present invention;

[0029] Figure 2 A top view of a battery cover assembly provided in an embodiment of the present invention;

[0030] Figure 3 for Figure 2 Sectional view of the AA section;

[0031] Figure 4 for Figure 3 A partial enlarged view of point B in the middle.

[0032] In the figure:

[0033] 100, cover plate body; 110, second mounting hole; 111, limiting step;

[0034] 200, connecting block; 210, first mounting hole; 211, first sink; 2111, first step surface; 2112, first side wall; 212, second sink; 2121, second step surface; 2122, second side wall;

[0035] 300, pole; 310, plate portion; 320, first column portion; 321, support platform; 330, second column portion; 331, riveting portion; 332, welding portion;

[0036] 400, first plastic part; 410, third mounting hole; 420, receiving groove; 430, annular flange; 500, second plastic part; 510, fourth mounting hole; 600, sealing part. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0038] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0040] In the description of the present invention, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or are the positions or positional relationships in which the inventive product is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0041] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "disposed" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0042] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0043] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0044] like Figure 1-Figure 4 As shown, this embodiment provides a battery cover assembly, which includes a connecting block 200 and a pole 300. The connecting block 200 is provided with a first mounting hole 210, and the inner wall of the first mounting hole 210 is provided with a first sink 211, and the first sink 211 includes a first step surface 2111 and a first side wall 2112.

[0045] At least part of the pole 300 is a columnar structure, and the first mounting hole 210 is a circular hole. One end of the pole 300 in a columnar structure passes through the first mounting hole 210 and is riveted to the first step surface 2111 of the first sink 211. The end of the pole 300 riveted to the first step surface 2111 is expanded along the radial direction of the first mounting hole 210 to form a riveted portion 331. By setting at least part of the pole 300 in a columnar structure, the pole 300 can be expanded evenly around when riveted to the first step surface 2111, thereby improving the uniformity of force on the pole 300 and the connecting block 200. Furthermore, the riveted portion 331 is formed after the pole 300 is riveted to the connecting block 200, and the end face of the riveted portion 331 facing the connecting block 200 abuts against the first step surface 2111, and the peripheral side wall of the riveted portion 331 abuts against the first side wall 2112 of the first countersunk platform 211, and a seam is formed between the peripheral side wall of the riveted portion 331 and the first side wall 2112, and a welding portion 332 is formed between the riveted portion 331 and the first side wall 2112 by welding at the seam between the peripheral side wall of the riveted portion 331 and the first side wall 2112, and the riveted portion 331, the first countersunk platform 211, and the welding portion 332 are all coaxial with the first mounting hole 210.

[0046] It should be noted that in this embodiment, the center line of the welding portion 332 is along the radial direction of the first mounting hole 210 ( Figure 12112). Thus, when the riveted portion 331 of the pole 300 is welded to the first side wall 2112, most of the molten pool formed by the heat of the welding portion 332 is located on the first side wall 2112 of the first sink 211, and the volume of the pole 300 melted by heat is reduced, thereby reducing the influence of welding on the mechanical strength of the pole 300. While ensuring that the resistance value between the pole 300 and the connecting block 200 is small, the connection strength between the pole 300 and the connecting block 200 is large. When the pole 300 is fixed, the connecting block 200 can withstand a large push-pull force (≥1000N), and the pole 300 is not easy to deform during this process, and the welding portion 332 between the pole 300 and the connecting block 200 is not easy to crack, and the reliability of the battery cover assembly is high. It should be noted that the welding portion 332 is annular as a whole, and the center line of the welding portion 332 is a circle surrounded by the midpoints of the welding portion 332 along the radial direction of the first mounting hole 210.

[0047] Optionally, continue to see Figure 3 and Figure 4 In this embodiment, the diameter of the riveted portion 331 is d1, and the diameter of the center line of the welding portion 332 is d2. Since the peripheral side wall of the riveted portion 331 abuts against the first side wall 2112 of the first sink 211, the diameter of the joint between the peripheral side wall of the riveted portion 331 and the first side wall 2112 of the first sink 211 is also d1. The distance between the center line of the welding portion 332 and the peripheral side wall of the riveted portion 331 is n, and the relationship between n and d1 satisfies: 0.0125≤n / d1≤0.025, n=(d2-d1) / 2. Exemplarily, the value of n can be 0.1mm, 0.12mm, 0.14mm, 0.16mm, 0.18mm or 0.2mm, etc., and the value of n / d1 can be 0.0125, 0.0130, 0.0150, 0.0180, 0.0200 or 0.0250, etc. When the distance n between the center line of the welding portion 332 and the peripheral side wall of the riveted portion 331 is within the above range, and the relationship between n and d1 satisfies: 0.0125≤n / d1≤0.025, the push-pull force that the connecting block 200 can withstand can reach more than 1000N, and the connection between the pole 300 and the connecting block 200 is reliable and stable. At the same time, the resistance value between the pole 300 and the connecting block 200 is less than or equal to 0.035mΩ, which meets the overcurrent requirements of the pole 300, and the performance of the battery cover assembly is good.

[0048] Furthermore, along the radial direction of the first mounting hole 210, the weld width of the welding portion 332 is w, and the value range of w is 0.5mm≤w≤1.0mm. For example, the value of w can be 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm or 1.0mm. Figure 3), the penetration depth of the welding portion 332 is h, and the value range of h is 0.3mm≤h≤0.5mm. For example, the value of h can be 0.3mm, 0.35mm, 0.4mm, 0.45mm or 0.5mm, etc. By limiting the penetration width w and penetration depth h of the welding portion 332, it is ensured that the molten pool formed when the pole 300 and the connecting block 200 are welded is large enough, and it can be ensured that the welding strength between the pole 300 and the connecting block 200 is high, the welding quality is good, the connection between the two is reliable, stable, and the conductivity is good. Otherwise, when the penetration width w is small and the penetration depth h is shallow, it is easy to cause insufficient welding strength between the pole 300 and the connecting block 200, and the welding portion 332 between the pole 300 and the connecting block 200 is prone to cracking, and the reliability of assembly is reduced. In addition, the weld width w should not be too large, otherwise the molten volume during welding of the pole 300 will be too large, which will cause the mechanical strength of the pole 300 to decrease, and the pole 300 will be easily deformed or broken; the weld depth h should not be too large, otherwise there may be a risk of welding through the connecting block 200 during welding, resulting in the scrapping of the battery cover assembly.

[0049] Continue to see Figure 3 and Figure 4 In this embodiment, a second sinker 212 is further provided on the inner wall of the first mounting hole 210. The second sinker 212 is located at a position close to the end of the first mounting hole 210 relative to the first sinker 211. The second sinker 212 is coaxial with the first sinker 211, and the diameter of the second sinker 212 along the radial direction of the first mounting hole 210 is greater than the diameter of the first sinker 211. The second sinker 212 includes a second step surface 2121 and a second side wall 2122. The second step surface 2121 is adjacent to the first side wall 2112 of the first sinker 211, and the second side wall 2122 is adjacent to the end surface of the connecting block 200 on which the second sinker 212 is provided. By setting the second sinker 212, the riveted portion 331 and the welding portion 332 can be located below the end surface of the connecting block 200 on the side where the second sinker 212 is provided, which has a good protective effect on the connection position between the pole 300 and the connecting block 200, reduces the risk of explosion holes and explosion points in the welding portion 332, and helps to improve the flatness of the connecting block 200, meets the surface flatness requirements of the battery cover assembly, and has high dimensional accuracy.

[0050] Further, along the axial direction of the first mounting hole 210, the height difference between the first step surface 2111 and the second step surface 2121 is S1, and the value range of S1 is: S1 ≥ 1.0 mm. For example, the value of S1 can be 1.0 mm, 2.0 mm, 3.0 mm, etc. Along the axial direction of the first mounting hole 210, the height of the riveted portion 331 is X, and the relationship between X and S1 satisfies: 0 mm ≤ S1-X ≤ 0.2 mm. For example, the value of S1-X can be 0 mm, 0.05 mm, 0.1 mm, 0.15 mm or 0.2 mm, etc. By adopting the above-mentioned size restriction, the end of the riveted portion 331 along the axial direction of the first mounting hole 210 will not exceed the first side wall 2112 of the first sink 211, which is convenient for welding operations, and can play a certain protective role on the riveted portion 331 and the welding portion 332, avoiding the riveted portion 331 and the welding portion 332 from being directly hit.

[0051] Along the axial direction of the first mounting hole 210, the height difference between the second step surface 2121 and the end surface of the connecting block 200 on the side where the second sink 212 is provided is S2, and the value range of S2 is: 0.1mm≤S2≤1.0mm. For example, the value of S2 can be 0.1mm, 0.2mm, 0.4mm, 0.6mm, 0.8mm or 1.0mm, etc. By adopting the above-mentioned size setting, the welding part 332 and the riveting part 331 will not protrude from the end surface of the connecting block 200 on the side where the second sink 212 is provided, which is beneficial to protect the connection position between the two. The height difference between the second step surface 2121 and the end surface of the connecting block 200 on the side where the second sink 212 is provided is small, which facilitates the welding operation between the riveting part 331 and the first side wall 2112. Otherwise, when the height difference between the second step surface 2121 and the end surface of the connecting block 200 on the side with the second sinker 212 is large, welding will be more difficult and inconvenient to operate, and the space in the axial direction of the first mounting hole 210 will be wasted, which is not conducive to thinning the thickness of the battery cover assembly and the energy density of the battery is low.

[0052] Furthermore, along the axial direction of the first mounting hole 210, the distance between the top of the welding portion 332 and the second step surface 2121 is e, and the value range of e is: 0mm≤e≤0.1mm. For example, the value of e can be 0mm, 0.02mm, 0.04mm, 0.06mm, 0.08mm or 0.1mm, etc. In this way, the welding portion 332 is prevented from protruding from the end surface of the side of the connecting block 200 where the second sink 212 is provided, and the risk of explosion holes and explosion points in the welding portion 332 is reduced.

[0053] Continue to see Figure 1 , Figure 3 and Figure 4The battery cover assembly in this embodiment also includes a cover body 100, which is provided with a second mounting hole 110. One end of the pole 300 in a columnar structure passes through the second mounting hole 110 and the first mounting hole 210 and is riveted to the first step surface 2111 of the first sink 211.

[0054] Optionally, the pole 300 in this embodiment includes a plate body 310, a first column body 320, and a second column body 330 connected in sequence, wherein the plate body 310 is arranged on the side of the cover body 100 away from the connection block 200, and the second column body 330 passes through the second mounting hole 110 and the first mounting hole 210 in sequence and is riveted to the first step surface 2111 of the first sink 211, and one end of the second column body 330 riveted to the first step surface 2111 is expanded along the radial direction of the first mounting hole 210 to form the above-mentioned riveted portion 331. After the pole 300 is assembled with the connection block 200 and the cover body 100, the first column body 320 is penetrated in the second mounting hole 110, and the second column body 330 is penetrated in the first mounting hole 210. The rivet portion 331 and the plate portion 310 respectively press the cover body 100 from both sides of the cover body 100 , so that the connection block 200 and the pole 300 are installed and fixed on the cover body 100 , and the connection between the pole 300 and the cover body 100 is reliable and stable.

[0055] In addition, the diameter of the first column portion 320 of the pole 300 is greater than the diameter of the second column portion 330, and a transition support platform 321 is formed between the peripheral side wall of the first column portion 320 and the peripheral side wall of the second column portion 330. The support platform 321 can support the end face of the connecting block 200 close to the cover body 100, so that when the pole 300 and the connecting block 200 are riveted, the connecting block 200 can be well supported, which is beneficial to improving the yield rate of riveting, and the flatness of the connecting block 200 is relatively high.

[0056] Furthermore, in this embodiment, there is a pre-assembly gap f between the peripheral side wall of the second column portion 330 and the inner wall of the first mounting hole 210, and the value range of f is 0.05mm≤f≤0.15mm. For example, the value of f can be 0.05mm, 0.1mm or 0.15mm, etc. By setting the pre-assembly gap f between the peripheral side wall of the second column portion 330 and the inner wall of the first mounting hole 210, on the one hand, the second column portion 330 is easily installed in the first mounting hole 210, and plays a certain limiting role on the pole 300, ensuring the accurate positioning between the pole 300 and the connecting block 200; on the other hand, the pre-assembly gap f also provides space for the second column portion 330 to expand along the radial direction of the first mounting hole 210, avoiding the large stress between the second column portion 330 and the connecting block 200 when the pole 300 and the connecting block 200 are riveted, resulting in cracking or deformation of the connecting block 200. Of course, the value of the above-mentioned pre-assembly gap f should not be too small, otherwise when the pole 300 is riveted to the connection block 200, the connection block 200 is prone to cracking or deformation, and the assembly effect is not good. The above-mentioned pre-assembly gap f should not be too large, otherwise the positioning effect between the pole 300 and the connection block 200 is not good, the assembly accuracy is reduced, and after the pole 300 is riveted to the connection block 200, due to the large pre-assembly gap f, there is still a gap between the peripheral side wall of the second column part 330 and the inner wall of the first mounting hole 210, the contact area between the pole 300 and the connection block 200 is reduced, the conductive effect is reduced, the resistance value between the pole 300 and the connection block 200 is increased, and the internal resistance of the battery is increased.

[0057] Continue to see Figure 1 , Figure 3 and Figure 4The battery cover assembly in this embodiment further includes a first plastic part 400, a second plastic part 500 and a sealing part 600. The first plastic part 400 is arranged on the side of the cover body 100 away from the plate body 310 of the pole 300, and the second plastic part 500 is arranged on the side of the cover body 100 close to the plate body 310 of the pole 300. The first plastic part 400 is provided with a third mounting hole 410, and the second plastic part 500 is provided with a fourth mounting hole 510. The second column part 330 of the pole 300 passes through the fourth mounting hole 510, the second mounting hole 110, the third mounting hole 410 and the first mounting hole 210 in sequence and is connected to the connecting block 200. The first column part 320 of the pole 300 is arranged in the fourth mounting hole 510, the second mounting hole 110 and the third mounting hole 410, and the second column part 330 of the pole 300 is arranged in the first mounting hole 210. Along the axial direction of the first mounting hole 210, the rivet portion 331 of the pole 300 presses the connection block 200 and the first plastic part 400 against one end surface of the cover body 100, the first plastic part 400 is sandwiched between the connection block 200 and the cover body 100, and the connection block 200 is insulated from the cover body 100 by the first plastic part 400. Along the axial direction of the first mounting hole 210, the plate body 310 of the pole 300 presses the second plastic part 500 against the other end surface of the cover body 100, the second plastic part 500 is sandwiched between the plate body 310 and the cover body 100, and the pole 300 is insulated from the cover body 100 by the second plastic part 500. The seal 600 is sleeved on the first column portion 320 of the pole 300, and the seal 600 is sandwiched between the peripheral side wall of the first column portion 320 and the inner wall of the second mounting hole 110. The seal 600 seals the gap between the pole 300 and the cover body 100, and insulates the pole 300 from the cover body 100.

[0058] Furthermore, a receiving groove 420 is provided on the side of the first plastic part 400 facing away from the cover body 100, and at least a portion of the connecting block 200 is embedded in the receiving groove 420. By providing the receiving groove 420, on the one hand, the positioning accuracy between the connecting block 200 and the first plastic part 400 can be improved to ensure good assembly between the two; on the other hand, the axial direction ( Figure 3 The thickness in the Z-axis direction (as shown in ) is beneficial to improving the energy density of the battery.

[0059] Optionally, there is a pre-assembly gap b between the circumferential side wall of the connecting block 200 and the inner wall of the receiving groove 420, and the value range of b is 0.3mm≤b≤0.5mm. For example, the value of b can be 0.3mm, 0.4mm or 0.5mm, etc. By setting the pre-assembly gap b between the circumferential side wall of the connecting block 200 and the inner wall of the receiving groove 420, on the one hand, the connecting block 200 is easily installed in the receiving groove 420, and a certain limiting effect is played on the connecting block 200, ensuring the accurate positioning between the first plastic part 400 and the connecting block 200; on the other hand, the pre-assembly gap b also provides a radial direction of the connecting block 200 along the first mounting hole 210 ( Figure 3 The pre-assembly gap b should provide space for the expansion of the material (in the Y-axis direction shown in the figure) to avoid the stress between the first plastic part 400 and the connecting block 200 being large when the pole 300 and the connecting block 200 are riveted, which may cause the first plastic part 400 to crack or deform. Of course, the value of the pre-assembly gap b should not be too small, otherwise the first plastic part 400 is prone to cracking or deformation when the pole 300 and the connecting block 200 are riveted, and the assembly effect is not good. The pre-assembly gap b should not be too large, otherwise the positioning effect between the first plastic part 400 and the connecting block 200 is not good, the assembly accuracy is reduced, and after the pole 300 and the connecting block 200 are riveted, due to the large pre-assembly gap b, there is still a gap between the peripheral side wall of the connecting block 200 and the inner wall of the accommodating groove 420, the connecting block 200 is easy to loosen, and the assembly strength of the battery cover assembly is low.

[0060] Optionally, an annular flange 430 is provided on one side of the first plastic part 400 close to the cover body 100, and a limiting step 111 is provided on one side of the cover body 100 close to the first plastic part 400. The limiting step 111 is located in the circumference of the second mounting hole 110 and is coaxial with the second mounting hole 110. The annular flange 430 cooperates with the limiting step 111, so that the positioning between the first plastic part 400 and the cover body 100 is accurate, which helps to improve the assembly accuracy between the first plastic part 400 and the cover body 100, and the assembly yield is high. More preferably, one end of the sealing member 600 can extend into the third mounting hole 410 of the first plastic part 400, thereby sealing the gap between the first column portion 320 of the pole 300 and the inner wall of the third mounting hole 410, and the sealing effect of the battery cover assembly is better.

[0061] This embodiment also provides a battery, including a shell, a pole group, and the above-mentioned battery cover assembly. One side of the shell is provided with an opening, the pole group is installed in the shell through the opening, and the battery cover assembly is encapsulated in the opening of the shell. The pole ear of the pole group is connected to the plate body 310 of the pole 300 of the battery cover assembly, and the pole group is connected to the external circuit through the pole 300.

[0062] By adopting the battery cover assembly in this embodiment, the resistance value between the pole 300 and the connecting block 200 can be reduced. When the pole 300 is connected to the external circuit, the conductive effect is good, the heating problem of the battery cover assembly during charging and discharging is alleviated, and the internal resistance of the battery is small. At the same time, the mechanical strength of the pole 300 itself is high, the pole 300 and the connecting block 200 can withstand large push-pull stress, the welding part 332 is not easy to crack, the connection strength between the pole 300 and the connecting block 200 is high, the assembly structure of the battery cover assembly is stable and reliable, and the battery is not easy to fail.

[0063] The following is a push-pull force test and a resistance value test on samples after the poles 300 with different diameters are assembled with the connection block 200 and the cover body 100.

[0064] Among them, the push-pull force test includes: fixing the pole 300 and the cover body 100, applying a pulling force away from the cover body 100 or a pushing force toward the cover body 100 to the connecting block 200, when the welding portion 332 between the pole 300 and the connecting block 200 cracks or the resistance value between the pole 300 and the connecting block 200 changes, the pushing force or pulling force at this moment is the maximum value of the push-pull force that the pole 300 and the connecting block 200 can withstand, that is, the push-pull force listed in Table 1, Table 2 and Table 3 below.

[0065] The resistance value test includes: connecting one detection end of the resistance meter to the plate body 310 of the pole 300, and connecting the other detection end of the resistance meter to the connection block 200, thereby the resistance value between the pole 300 and the connection block 200 can be measured by the resistance meter, that is, the resistance value listed in Table 1, Table 2 and Table 3 below.

[0066] Specifically, Table 1 shows the test results of the maximum push-pull force that can be borne between the pole 300 and the connecting block 200 and the resistance value between the pole 300 and the connecting block 200 after adjusting the diameter d2 of the center line of the welding portion 332 when the diameter d1 of the riveted portion 331 of the pole 300 is 8 mm.

[0067] Table 1

[0068]

[0069] It can be seen from the results in Table 1 that in Comparative Examples 1 and 2, the value of n / d1 is less than the minimum value of 0.0125≤n / d1≤0.025. At this time, the push-pull force that can be borne between the pole 300 and the connecting block 200 is less than 1000N, which cannot meet the assembly strength requirements of the battery cover assembly. In Comparative Examples 1 and 2, the pole 300 may also be deformed, resulting in insufficient clamping force on the seal 600, and the battery cover assembly is prone to sealing failure, and the battery cover assembly is unqualified.

[0070] In Comparative Examples 3 and 4, the value of n / d1 is greater than the maximum value of 0.0125≤n / d1≤0.025. At this time, the push-pull force that can be borne between the pole 300 and the connecting block 200 is greater than 1000N, which meets the assembly strength requirements of the battery cover assembly. However, the resistance value between the pole 300 and the connecting block 200 is greater than 0.035mΩ, and the conductivity is poor. When the battery is charged and discharged, the battery cover assembly is prone to heat up and increases the internal resistance of the battery. Its current capacity cannot meet the requirements, and the battery cover assembly is unqualified.

[0071] In Example 1, Example 2, Example 3, Example 4, Example 5, and Example 6, the value of n / d1 is in the range of 0.0125≤n / d1≤0.025, the push-pull force that can be withstood between the pole 300 and the connecting block 200 is greater than 1000N, satisfying the assembly strength requirements of the battery cover assembly, the battery cover assembly has high reliability, and the resistance value between the pole 300 and the connecting block 200 is less than 0.035mΩ, and the conductivity is good. When the battery is charged and discharged, the battery cover assembly is not easy to heat up, the internal resistance of the battery is small, the current capacity meets the requirements, and the battery cover assembly is qualified.

[0072] Table 2 shows the test results of the maximum push-pull force that can be borne between the pole 300 and the connection block 200 and the resistance value between the pole 300 and the connection block 200 after adjusting the diameter d2 of the center line of the welding portion 332 when the diameter d1 of the riveted portion 331 of the pole 300 is 10 mm.

[0073] Table 2

[0074]

[0075] It can be seen from the results in Table 2 that in Comparative Examples 1 and 2, the value of n / d1 is less than the minimum value of 0.0125≤n / d1≤0.025. At this time, the push-pull force that can be borne between the pole 300 and the connecting block 200 is less than 1000N, which cannot meet the assembly strength requirements of the battery cover assembly. The reliability of the battery cover assembly is not high, and the battery cover assembly is unqualified.

[0076] In Comparative Examples 3 and 4, the value of n / d1 is greater than the maximum value of 0.0125≤n / d1≤0.025. At this time, the push-pull force that can be borne between the pole 300 and the connecting block 200 is greater than 1000N, which meets the assembly strength requirements of the battery cover assembly. However, the resistance value between the pole 300 and the connecting block 200 is greater than 0.035mΩ, and the conductivity is poor. When the battery is charged and discharged, the battery cover assembly is prone to heat up and increases the internal resistance of the battery. Its current capacity cannot meet the requirements, and the battery cover assembly is unqualified.

[0077] In Example 1, Example 2, Example 3, Example 4, Example 5 and Example 6, the value of n / d1 is in the range of 0.0125≤n / d1≤0.025, the push-pull force that can be withstood between the pole 300 and the connecting block 200 is greater than 1000N, satisfying the assembly strength requirements of the battery cover assembly, the battery cover assembly has high reliability, and the resistance value between the pole 300 and the connecting block 200 is less than 0.035mΩ, and the conductivity is good. When the battery is charged and discharged, the battery cover assembly is not easy to heat up, the internal resistance of the battery is small, the current capacity meets the requirements, and the battery cover assembly is qualified.

[0078] Table 3 shows the test results of the maximum push-pull force that can be borne between the pole 300 and the connection block 200 and the resistance value between the pole 300 and the connection block 200 after adjusting the diameter d2 of the center line of the welding portion 332 when the diameter d1 of the riveted portion 331 of the pole 300 is 11 mm.

[0079] Table 3

[0080]

[0081] It can be seen from the results in Table 3 that in Comparative Examples 1 and 2, the value of n / d1 is less than the minimum value of 0.0125≤n / d1≤0.025. At this time, the push-pull force that can be borne between the pole 300 and the connecting block 200 is less than 1000N, which cannot meet the assembly strength requirements of the battery cover assembly. The reliability of the battery cover assembly is low, and the battery cover assembly is unqualified.

[0082] In Comparative Examples 3 and 4, the value of n / d1 is greater than the maximum value of 0.0125≤n / d1≤0.025. At this time, the push-pull force that can be borne between the pole 300 and the connecting block 200 is greater than 1000N, which meets the assembly strength requirements of the battery cover assembly. However, the resistance value between the pole 300 and the connecting block 200 is greater than 0.035mΩ, and the conductivity is poor. When the battery is charged and discharged, the battery cover assembly is prone to heat up and increases the internal resistance of the battery. Its current capacity cannot meet the requirements, and the battery cover assembly is unqualified.

[0083] In Example 1, Example 2, Example 3, Example 4, Example 5 and Example 6, the value of n / d1 is in the range of 0.0125≤n / d1≤0.025, the push-pull force that can be withstood between the pole 300 and the connecting block 200 is greater than 1000N, satisfying the assembly strength requirements of the battery cover assembly, the battery cover assembly has high reliability, and the resistance value between the pole 300 and the connecting block 200 is less than 0.035mΩ, and the conductivity is good. When the battery is charged and discharged, the battery cover assembly is not easy to heat up, the internal resistance of the battery is small, the current capacity meets the requirements, and the battery cover assembly is qualified.

[0084] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A battery cover assembly, characterized in that: include: The connecting block is provided with a first mounting hole, the inner wall of the first mounting hole is provided with a first sinking platform, and the first sinking platform includes a first step surface and a first side wall; A pole, one end of the pole passes through the first mounting hole and is riveted to the first step surface, the end of the pole riveted to the first step surface is expanded along the radial direction of the first mounting hole to form a riveted portion, the peripheral side wall of the riveted portion is welded to the first side wall to form a welding portion between the riveted portion and the first side wall, and the riveted portion, the first sink, and the welding portion are all coaxial with the first mounting hole; The diameter of the riveted portion is d1, the diameter of the center line of the welded portion is d2, and the distance between the center line of the welded portion and the peripheral side wall of the riveted portion is n; The relationship between n and d1 satisfies: 0.0125≤n / d1≤0.025, n=(d2-d1) / 2.

2. The battery cover assembly according to claim 1, characterized in that: Along the radial direction of the first mounting hole, the weld width of the welding portion is w, and the value range of w is: 0.5mm≤w≤1.0mm; And / or, along the axial direction of the first mounting hole, the penetration depth of the welding portion is h, and the value range of h is: 0.3mm≤h≤0.5mm.

3. The battery cover assembly according to claim 1, characterized in that: A second sinker is provided on the inner wall of the first mounting hole, and the second sinker is located near the port of the first mounting hole relative to the first sinker, and the second sinker includes a second step surface and a second side wall, and the second step surface is adjacent to the first side wall of the first sinker.

4. The battery cover assembly according to claim 3, characterized in that: Along the axial direction of the first mounting hole, a height difference between the first step surface and the second step surface is S1, and a value range of S1 is: S1 ≥ 1.0 mm.

5. The battery cover assembly according to claim 4, characterized in that: Along the axial direction of the first mounting hole, the height of the riveted portion is X, and the relationship between X and S1 satisfies: 0mm≤S1-X≤0.2mm.

6. The battery cover assembly according to claim 3, characterized in that: Along the axial direction of the first mounting hole, a height difference between the second step surface and an end surface of the connecting block on a side where the second sink is provided is S2, and a value range of S2 is: 0.1 mm ≤ S2 ≤ 1.0 mm.

7. The battery cover assembly according to claim 3, characterized in that: Along the axial direction of the first mounting hole, the distance between the top of the welding portion and the second step surface is e, and the value range of e is: 0mm≤e≤0.1mm.

8. The battery cover assembly according to claim 1, characterized in that: The battery cover assembly also includes a cover body, the cover body is provided with a second mounting hole, and the pole passes through the second mounting hole and the first mounting hole and is riveted to the first step surface of the first sink.

9. The battery cover assembly according to claim 8, characterized in that: The pole comprises a plate portion, a first column portion and a second column portion which are connected in sequence, the second column portion passes through the second mounting hole and the first mounting hole and is riveted to the first step surface of the first sink, the plate portion is located on a side of the cover body away from the riveted portion, the first column portion is penetrated through the second mounting hole, and the second column portion is penetrated through the first mounting hole; There is a pre-assembly gap f between the peripheral side wall of the second column portion and the inner wall of the first mounting hole, and the value range of f is 0.05mm≤f≤0.15mm.

10. A battery, characterized in that: A battery cover assembly comprising any one of claims 1-9.

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