Screw connection element and battery pack

Abstract

Screw connection element (100) comprising: a threaded rod (10) wherein the threaded rod (10) is designed for screwing to a component to be joined; and a flange washer (20) wherein the flange washer (20) has a pressing surface (21) wherein an end of the threaded rod (10) is connected to the pressing surface (21), the pressing surface (21) is designed for pressing against the component to be joined, and wherein a scratch-resistant arc surface (22) surrounds a circumferential edge of the pressing surface (21), wherein the scratch-resistant arc surface (22) is tangential to the pressing surface (21).

Description

Threaded connection and battery pack

[0001] The present application claims priority to the Chinese patent application No. 202420818465.7, filed on April 18, 2024, to the Chinese Patent Office, the whole content of the above application being incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to the technical field of batteries, in particular to a threaded connection and a battery pack. BACKGROUND

[0003] In the related art, a threaded connection is used to connect two pieces to be connected together, which is a commonly used fixed connection method in production. Specifically, the threaded connection includes a threaded rod and a flange plate, the flange plate is connected to one end of the threaded rod. When connecting, the threaded rod passes through the pre-set connection holes of the two pieces to be connected, and the threaded rod is at least threadedly connected with one piece to be connected away from the flange plate. The flange plate presses one piece to be connected against the other piece to be connected, thereby achieving the fixed connection of the two pieces to be connected. SUMMARY

[0004] However, in some cases, the periphery of the flange plate of the threaded connection is a sharp right-angle edge, and the hardness of the threaded connection is greater than that of the pieces to be connected. During the screwing process of the threaded connection, the sharp right-angle edge of the flange plate is easy to cut the pieces to be connected with a relatively soft hardness, resulting in flying filaments and debris.

[0005] The present application provides a threaded connection, which includes a threaded rod and a flange plate. The threaded rod is used to be screwed with a piece to be connected. The flange plate has a pressing surface. One end of the threaded rod is connected to the pressing surface. The pressing surface is used to be pressed on the piece to be connected. The periphery of the pressing surface is provided with a scratch-preventing arc surface. The scratch-preventing arc surface is tangentially arranged with the pressing surface.

[0006] The present application also provides a battery pack, which includes the above-mentioned threaded connection. ADVANTAGEOUS EFFECTS

[0007] The threaded connection provided by the present application sets the scratch-preventing arc surface on the periphery of the pressing surface of the flange plate. The scratch-preventing arc surface is tangentially arranged with the pressing surface. During the screwing process of the threaded connection, the scratch-preventing arc surface can avoid the periphery of the flange plate cutting the piece to be connected, thereby avoiding the generation of flying filaments and debris, and effectively improving the technical problem that the threaded connection is easy to cut flying filaments and debris on the piece to be connected.

[0008] The battery pack provided by the present application adopts the above-mentioned threaded connection, which improves the technical problem that the threaded connection is easy to cut flying filaments and debris on the piece to be connected, and ensures the cleanliness inside the battery pack. BRIEF DESCRIPTION OF DRAWINGS

[0009] Fig. 1 is a perspective view of a threaded connector according to an embodiment of the present application;

[0010] Fig. 2 is a perspective view of a threaded connector according to another embodiment of the present application;

[0011] Fig. 3 is a structural view of a threaded connector according to yet another embodiment of the present application;

[0012] Fig. 4 is a partial structural view of the threaded connector of Fig. 3;

[0013] Fig. 5 is a structural sectional view of a battery pack according to an embodiment of the present application. Embodiments of the present application

[0014] First, in the related art, two pieces to be connected are connected together by using a threaded connector, which is a commonly used fixed connection method in production. Specifically, as shown in Fig. 5, taking the assembly of a battery pack 200 as an example, in order to fix a battery module 210 in a box 220, two ends of the battery module 210 are usually provided with aluminum end plates 211, and through holes 212 are formed in the aluminum end plates 211. After the battery module 210 is placed in the box 220, a threaded connector 100 is used to pass through the through holes 212 in the aluminum end plates 211, so that the threaded connector 100 is screwed with the box 220 (i.e., the aluminum end plates 211 and the box 220 are two pieces to be connected). When a flange plate 20 of the threaded connector 100 presses the end plates tightly in the box 220, the fixing of the battery module 210 in the box 220 is completed.

[0015] However, the peripheral edge of the flange plate 20 of the existing threaded connector 100 is formed as a sharp right-angle edge during cold heading, and the hardness of the threaded connector 100 is greater than that of the aluminum end plates 211. Therefore, during the tightening process, the sharp right-angle edge of the flange plate 20 easily cuts the aluminum end plates 211 with relatively soft hardness, resulting in flying filaments and debris, and causing the cleanliness inside the battery pack 200 to be substandard (Note: The battery pack 200 is an electrical product, and the cleanliness inside the product is strictly controlled, especially the control of metal particles).

[0016] Therefore, in order to solve the above technical problems, as shown in Figs. 1 and 3, embodiments of the present application provide a threaded connector 100, which includes a threaded rod 10 and a flange plate 20. The threaded rod 10 is used to be screwed with a piece to be connected. The flange plate 20 has a pressing surface 21. One end of the threaded rod 10 is connected to the pressing surface 21. The pressing surface 21 is used to be pressed on the piece to be connected. A scratch-preventing arc surface 22 is arranged around the peripheral edge of the pressing surface 21. The scratch-preventing arc surface 22 is arranged tangentially to the pressing surface 21.

[0017] Specifically, the threaded connecting piece 100 can be a bolt, a screw or a screw, for example, in the structural scheme shown in FIG. 1, the threaded connecting piece 100 is specifically a flange bolt, and the threaded connecting piece 100 includes a threaded rod 10 and a flange plate 20 connected to each other.

[0018] The threaded rod 10 is a cylindrical rod, and the threaded rod 10 has a connecting end 11 and a free end 12 opposite to each other in the circumferential direction of the threaded rod 10. The connecting end 11 is fixedly connected to the flange plate 20, and the free end 12 is spaced apart from the flange plate 20. A guide inclined surface 121 can be provided on the free end 12. The guide inclined surface 121 can play a guiding role when the threaded rod 10 penetrates into the through hole of the to-be-connected piece, so that the threaded rod 10 can be more quickly and smoothly penetrated into the through hole of the to-be-connected piece. An external thread is provided on the outer periphery of the threaded rod 10, so that the threaded rod 10 can be screwed with the to-be-connected piece.

[0019] It should be noted that there are generally two to-be-connected pieces, and the threaded rod 10 can be screwed with both to-be-connected pieces or only with the to-be-connected piece farther away from the flange plate 20. The specific situation needs to be determined according to whether the threaded holes 221 are provided on both to-be-connected pieces.

[0020] For example, as shown in FIG. 5, when it is necessary to fix the aluminum end plate 211 on the battery module 210 to the box body 220, the aluminum end plate 211 and the box body 220 are components that need to be connected to each other, so the aluminum end plate 211 and the box body 220 are both the “to-be-connected pieces” defined in the embodiment. In the figure, the aluminum end plate 211 is provided with a connecting through hole 212, and the inner wall of the connecting through hole 212 is not provided with a thread. The box body 220 is provided with a threaded hole 221 corresponding to the connecting through hole 212, and the threaded hole 221 is provided with an internal thread. Therefore, the threaded rod 10 is screwed only with the box body 220, but not with the aluminum end plate 211.

[0021] Of course, the threaded connecting piece 100 of the present application is not limited to be applied in the battery pack 200. When the threaded connecting piece 100 of the present application is applied in other fields, the threaded rod 10 of the threaded connecting piece 100 can be screwed with both to-be-connected pieces.

[0022] In addition, the outer diameter, length, thread shape, thread rotation direction, pitch, lead, etc. of the threaded rod 10 can be flexibly designed according to actual needs, and are not specifically limited here.

[0023] As shown in FIG. 1, the flange plate 20 is in the shape of a circular plate, and the flange plate 20 has a pressing surface 21 for pressing the to-be-connected piece. The connecting end 11 of the threaded rod 10 is fixedly connected to the pressing surface 21. Specifically, the threaded rod 10 is integrally formed with the flange plate 20, and the threaded rod 10 is usually coaxially arranged with the flange plate 20. The pressing surface 21 is a plane, and the pressing surface 21 is used to press the to-be-connected piece, so that the flange plate 20 can press the to-be-connected piece tightly.

[0024] It should be noted that, as described above, there are usually two connecting pieces, and the pressing surface 21 is pressed against the connecting piece closer to the flange 20. For example, as shown in FIG. 5, in the battery pack 200, the aluminum end plate 211 and the box 220 are two connecting pieces that need to be connected, the threaded rod 10 passes through the aluminum end plate 211 and is screwed with the box 220, and the pressing surface 21 of the flange 20 is pressed against the aluminum end plate 211.

[0025] As shown in FIGS. 1 and 3, the circumferential edge of the pressing surface 21 is provided with a scratch-preventing arc surface 22. Specifically, one side of the scratch-preventing arc surface 22 is connected with the pressing surface 21, and the other side extends in a direction away from the threaded rod 10, and the scratch-preventing arc surface 22 is tangent to the pressing surface 21. Therefore, when the threaded connecting piece 100 is tightened and the pressing surface 21 is rotated against the aluminum end plate 211, because the scratch-preventing arc surface 22 is a curved surface and is tangent to the circumferential edge of the pressing surface 21, the circumferential edge of the flange 20 does not cut the aluminum end plate 211 during rotation relative to the aluminum end plate 211, so that aluminum flying filaments and debris are not generated, effectively solving the technical problem that the bolt in the battery module 210 easily cuts flying filaments and debris on the aluminum end plate 211 when fixing the aluminum end plate 211.

[0026] It should be noted that, in order to form the scratch-preventing arc surface 22 on the circumferential edge of the pressing surface 21, the threaded connecting piece 100 can be produced by a mold, and the mold is provided with a forming arc surface corresponding to the position of the circumferential edge of the pressing surface 21, so that the scratch-preventing arc surface 22 is formed by the forming arc surface. It can be understood that in this way, the scratch-preventing arc surface 22 can be better formed on the circumferential edge of the pressing surface 21, and the production cost is not increased.

[0027] Optionally, in some possible implementations, please refer to FIGS. 3 and 4, the radius of the scratch-preventing arc surface 22 is R, R is greater than or equal to 0.7 millimeters and less than or equal to 0.9 millimeters.

[0028] Specifically, the radius R of the scratch-preventing arc surface 22 can be 0.7 millimeters, 0.71 millimeters, 0.72 millimeters, 0.73 millimeters, 0.74 millimeters, 0.75 millimeters, 0.76 millimeters, 0.77 millimeters, 0.78 millimeters, 0.79 millimeters, 0.8 millimeters, 0.81 millimeters, 0.82 millimeters, 0.83 millimeters, 0.84 millimeters, 0.85 millimeters, 0.86 millimeters, 0.87 millimeters, 0.88 millimeters, 0.89 millimeters, 0.9 millimeters, etc.

[0029] It can be understood that if the radius of the scratch-resistant arc surface 22 is too small, the corresponding forming arc surface on the mold also needs to be set smaller, which will increase the manufacturing difficulty of the mold, and easily affect the size accuracy of the forming arc surface, leading to the size of the scratch-resistant arc surface 22 being difficult to control. If the radius of the scratch-resistant arc surface 22 is too large, it will lead to the area of the pressing surface 21 being small, leading to the contact area between the flange plate 20 and the aluminum end plate 211 being small, which will easily cause the flange plate 20 to crush (i.e. press deform) the aluminum end plate 211.

[0030] Therefore, by controlling the radius of the scratch-resistant arc surface 22 to be within 0.7mm to 0.9mm, the manufacturing difficulty of the mold can be avoided, the size accuracy of the forming arc surface can be avoided, the size of the scratch-resistant arc surface 22 can be more controllable, and the area of the pressing surface 21 can be avoided to be small, leading to the contact area between the flange plate 20 and the aluminum end plate 211 being small, thereby avoiding the situation of the flange plate 20 crushing the aluminum end plate 211.

[0031] Optionally, in some possible implementations, referring to FIG. 3, the threaded rod 10 has a connecting end 11 and a free end 12 opposite in the axial direction of the threaded rod 10, the connecting end 11 is connected to the pressing surface 21, and the free end 12 is spaced apart from the pressing surface 21. The pressing surface 21 is also inclined relative to the threaded rod 10, and the pressing surface 21 has a first connection position 21a connected to the threaded rod 10 and a second connection position 21b connected to the scratch-resistant arc surface 22, that is, the first connection position 21a extends in the circumferential direction of the threaded rod 10, the second connection position 21b extends in the circumferential direction of the scratch-resistant arc surface 22, and in the axial direction of the threaded rod 10, the distance between the first connection position 21a and the free end 12 is less than the distance between the second connection position 21b and the free end 12.

[0032] Specifically, in this embodiment, taking the orientation relationship of “flange plate 20 on top, threaded rod 10 on bottom” in FIG. 3 as an example, the flange surface extends outward from the threaded rod 10 while gradually tilting upward, at this time, the distance between the first connection position 21a and the free end 12 is less than the distance between the second connection position 21b and the free end 12, that is, in the axial direction of the threaded rod 10, the closer the position on the flange surface to the first connection position 21a, the lower the height of the position, and the farther the position on the flange surface from the first connection position 21a, the higher the height of the position, that is, as the threaded connection piece 100 is screwed, the position on the pressing surface 21 closer to the first connection position 21a will be combined with the aluminum end plate 211 before the position on the pressing surface 21 farther from the first connection position 21a.

[0033] Therefore, it can be understood that when the pressing surface 21 is attached to the aluminum end plate 211 at most positions, there is still a certain gap between the periphery of the pressing surface 21 (i.e., the position where the second connecting position 21b is located) and the aluminum end plate 211, so that the periphery of the pressing surface 21 can be prevented from cutting the aluminum end plate 211, the flying silk and debris can be avoided, and the cleanliness in the battery pack 200 can be ensured.

[0034] However, it can also be understood that if the angle at which the pressing surface 21 is inclined upward is too small, the effect of preventing the periphery of the pressing surface 21 from cutting the aluminum end plate 211 is not obvious enough, and if the angle at which the pressing surface 21 is inclined upward is too large, the contact area between the pressing surface 21 and the aluminum end plate 211 is too small, which can crush the aluminum end plate 211. Therefore, in the present embodiment, please refer to FIGS. 3 and 4, the included angle A between the pressing surface 21 and the threaded rod 10, specifically, the included angle A is the included angle between any straight line in the pressing surface 21 and the axis of the threaded rod 10, and the included angle A is greater than or equal to 90° and less than or equal to 91°.

[0035] Specifically, the specific value of the included angle A can be 90°, 90.1°, 90.2°, 90.3°, 90.4°, 90.5°, 90.6°, 90.7°, 90.8°, 90.9°, 91°, etc.

[0036] It can be understood that by controlling the included angle A between the pressing surface 21 and the threaded rod 10 to be between 90° and 91°, the situation that the scratch prevention effect is not obvious enough can be avoided, and the situation that the contact area between the pressing surface 21 and the aluminum end plate 211 is too small and the aluminum end plate 211 can be crushed can also be avoided.

[0037] It needs to be noted that during production, 90.5° can be taken as the basic size of the included angle A, so that even if there is a certain production error, the included angle A between the pressing surface 21 and the threaded rod 10 can be ensured to be between 90° and 91°.

[0038] Optionally, in some possible implementations, please refer to FIGS. 3 and 4, the flange plate 20 also has a vertically extending outer peripheral surface 23, the scratch prevention arc surface 22 is connected between the pressing surface 21 and the outer peripheral surface 23, the outer diameter of the scratch prevention arc surface 22 is D1, the outer diameter of the outer peripheral surface 23 is D2, and the outer diameter of the outer peripheral surface 23 is the maximum outer diameter of the flange plate 20. In the present embodiment, the ratio of D1 and D2 is K, and K is greater than or equal to 0.85 and less than or equal to 0.885.

[0039] Specifically, the specific value of K can be 0.85, 0.852, 0.855, 0.857, 0.858, 0.86, 0.862, 0.864, 0.865, 0.867, 0.869, 0.87, 0.871, 0.873, 0.875, 0.877, 0.879, 0.88, 0.881, 0.882, 0.883, 0.884, 0.885, and the like.

[0040] It can be understood that if the ratio of the outer diameter of the scratch-resistant arc surface 22 to the outer diameter of the outer peripheral surface 23 is less than 0.85, it indicates that the area of the pressing surface 21 is relatively small, which can cause the contact area between the flange plate 20 and the aluminum end plate 211 to be relatively small, and the aluminum end plate 211 is easily crushed. If the ratio of the outer diameter of the scratch-resistant arc surface 22 to the outer diameter of the outer peripheral surface 23 is greater than 0.885, it indicates that the difference in the outer diameter between the pressing surface 21 and the outer peripheral surface 23 is relatively small, which causes the size of the scratch-resistant arc surface 22 to be relatively small, and the size of the scratch-resistant arc surface 22 is difficult to control during production, affecting the scratch-resistant effect.

[0041] Therefore, by controlling the ratio of the outer diameter of the scratch-resistant arc surface 22 to the outer diameter of the outer peripheral surface 23 to be between 0.85 and 0.885, it can not only ensure that the flange plate 20 and the aluminum end plate 211 have sufficient contact area to avoid the aluminum end plate 211 being crushed, but also avoid the size of the scratch-resistant arc surface 22 being too small and difficult to control during production, ensuring the scratch-resistant effect.

[0042] Optionally, in some possible implementation manners, please refer to FIGS. 3 and 4, the flange plate 20 further has an upper side end surface 24 opposite to the pressing surface 21, and the outer peripheral surface 23 is connected between the scratch-resistant arc surface 22 and the upper side end surface 24. Specifically, in this embodiment, the distance between the upper side end surface 24 and the pressing surface 21 is the thickness of the flange plate 20, and in the axial direction of the threaded rod 10, the distance between the upper side end surface 24 and the pressing surface 21 is T, T is greater than or equal to 1.3 millimeters and less than or equal to 1.5 millimeters.

[0043] Specifically, the specific value of T can be 1.3 millimeters, 1.31 millimeters, 1.32 millimeters, 1.33 millimeters, 1.34 millimeters, 1.35 millimeters, 1.36 millimeters, 1.37 millimeters, 1.38 millimeters, 1.39 millimeters, 1.4 millimeters, 1.41 millimeters, 1.42 millimeters, 1.43 millimeters, 1.44 millimeters, 1.45 millimeters, 1.46 millimeters, 1.47 millimeters, 1.48 millimeters, 1.49 millimeters, 1.5 millimeters, and the like.

[0044] It can be understood that if the spacing between the upper end surface 24 and the pressing surface 21 is less than 1.3 mm, it indicates that the thickness of the flange plate 20 is small, and the locking force of the aluminum end plate 211 is insufficient. If the spacing between the upper end surface 24 and the pressing surface 21 is greater than 1.5 mm, it indicates that the thickness of the flange plate 20 is large, which will cause the volume and weight of the threaded connection piece 100 to be large, and the flange plate 20 is easy to interfere with the locking tool.

[0045] Therefore, in some possible implementations, by controlling the spacing between the upper end surface 24 and the pressing surface 21 to be between 1.3 mm and 1.5 mm, the flange plate 20 can have sufficient thickness to better lock the aluminum end plate 211, and the volume and weight of the threaded connection piece 100 can be avoided. The volume and weight of the threaded connection piece 100 are too large, and the weight of the battery pack 200 is increased.

[0046] In some possible implementations, as shown in FIG. 3, the upper end surface 24 and the outer peripheral surface 23 are also connected with a connecting arc surface 25, so that when the threaded connection piece 100 is produced, burrs are avoided between the upper end surface 24 and the outer peripheral surface 23, thereby ensuring the cleanliness inside the battery pack 200.

[0047] It should be noted here that the radius of the connecting arc surface 25 can be flexibly designed according to actual conditions, for example, in some possible implementations, the radius of the connecting arc surface 25 is less than the radius of the scratch-preventing arc surface 22. Based on the foregoing, the radius of the scratch-preventing arc surface 22 is greater than or equal to 0.7 mm and less than or equal to 0.9 mm, and thus the radius of the connecting arc surface 25 can be 0.6 mm, 0.5 mm, 0.4 mm, 0.3 mm, 0.2 mm, etc.

[0048] It can be understood that if the radius of the connecting arc surface 25 is greater than or equal to the radius of the scratch-preventing arc surface 22, in order to avoid the intersection of the connecting arc surface 25 and the scratch-preventing arc surface 22 (the surface structure after intersection is relatively complex and is not easy to produce), the size of the outer peripheral surface 23 in the axial direction of the threaded rod 10 needs to be increased, which will cause the flange plate 20 to be thick and the volume and weight of the threaded connection piece 100 to be large.

[0049] Therefore, by making the radius of the connecting arc surface 25 less than the radius of the scratch-preventing arc surface 22, the thickness of the flange plate 20 can be prevented from being large, and the volume and weight of the threaded connection piece 100 can be avoided from being large on the basis of preventing burrs.

[0050] In some possible implementation manners, as shown in FIG. 3, a screw head 30 is further protruded on the upper end surface 24, the screw head 30 is used for being clamped with a screwing tool (such as a screwdriver, a wrench, etc.), and a first transition arc surface 31 is connected between the screw head 30 and the upper end surface 24. When the threaded connecting piece 100 is produced, burrs can be avoided between the screw head 30 and the upper end surface 24, so as to ensure the cleanliness inside the battery pack 200.

[0051] It should be noted that the specific shape of the screw head 30 can be flexibly selected as needed, for example, the outer shape of the screw head 30 can be a polygonal prism, such as a square head (i.e., a four-polygonal prism), a hexagonal head (i.e., a six-polygonal prism), etc., or can also be a cylinder with a non-circular clamping groove 32.

[0052] For example, in some possible implementation manners, as shown in FIG. 2, the end of the screw head 30 away from the upper end surface 24 is recessed with a clamping groove 32, and in this embodiment, a plurality of clamping sub-grooves 321 are recessed on the inner circumferential wall of the clamping groove 32, the clamping sub-grooves 321 are arc grooves, and a second transition arc surface 322 is connected between adjacent two clamping sub-grooves 321. That is, in this embodiment, the screw head 30 is in a cylindrical shape, and the clamping groove 32 on the screw head 30 is a keyhole slot with an arc inner circumferential surface, avoiding the screw head 30 having a sharp corner or a right angle structure, so as to avoid burrs and ensure the cleanliness inside the battery pack 200.

[0053] In some possible implementation manners, as shown in FIG. 3, a third transition arc surface 13 is further connected between the threaded rod 10 and the pressing surface 21, and similarly, the first transition arc surface 31 can avoid burrs between the threaded rod 10 and the pressing surface 21, so as to ensure the cleanliness inside the battery pack 200.

[0054] In the second aspect, as shown in FIG. 5, the embodiments of the present application provide a battery pack 200, which comprises a battery module 210, a box body 220, and the threaded connecting piece 100 of any one of the above. The battery module 210 is installed in the box body 220, and the two ends of the battery module 210 are respectively provided with aluminum end plates 211, the aluminum end plates 211 are provided with connecting through holes 212, the box body 220 is provided with threaded holes 221, the threaded rod 10 of the threaded connecting piece 100 passes through the connecting through holes 212 and is screwed into the threaded holes 221, and the flange plate 20 is pressed on the aluminum end plate 211. Since the battery pack 200 of the present application adopts all the technical solutions of the above embodiments, it at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated here.

Claims

1. A threaded connection (100), wherein, The application relates to a threaded rod (10) for screwing with a piece to be connected, and a flange plate (20) having a pressing surface, one end of the threaded rod (10) being connected to the pressing surface (21) for pressing on the piece to be connected, and the periphery of the pressing surface (21) being provided with a scratch-preventing arc surface (22) tangential to the pressing surface (21). The radius of the scratch-preventing arc surface (22) is greater than or equal to 0.7 mm and less than or equal to 0.9 mm. The threaded rod (10) has a connecting end (11) and a free end (12) opposite to each other in the axial direction of the threaded rod (10), the connecting end (11) being connected to the pressing surface (21), and the free end (12) being spaced apart from the pressing surface (21). The pressing surface (21) is also provided to be inclined relative to the threaded rod (10), and the pressing surface (21) has a first connecting position (21a) connected to the threaded rod (10) and a second connecting position (21b) connected to the scratch-preventing arc surface (22), the distance between the first connecting position (21a) and the free end (12) being less than the distance between the second connecting position (21b) and the free end (12) in the axial direction of the threaded rod (10).

2. Threaded connection (100) according to claim 1, wherein The included angle between the pressing surface and the threaded rod (10) is greater than or equal to 90 DEG and less than or equal to 91 DEG.

3. Threaded connection (100) according to claim 1, wherein The flange plate also has an outer peripheral surface, the scratch-preventing arc surface (22) being connected between the pressing surface (21) and the outer peripheral surface, and the ratio of the outer diameter of the scratch-preventing arc surface (22) to the outer diameter of the outer peripheral surface is greater than or equal to 0.85 and less than or equal to 0.

885. The flange plate also has an upper side end surface opposite to the pressing surface (21), and the outer peripheral surface is connected between the scratch-preventing arc surface (22) and the upper side end surface; wherein the distance between the upper side end surface and the pressing surface is greater than or equal to 1.3 mm and less than or equal to 1.5 mm in the axial direction of the threaded rod (10).

4. Threaded connection (100) according to claim 3, wherein A connecting arc surface (25) is further connected between the upper side end surface and the outer peripheral surface.

5. Threaded connection (100) according to any one of claims 1-4, wherein, The radius of the connecting arc surface is less than the radius of the scratch-preventing arc surface (22).

6. Threaded connection (100) according to claim 5, wherein A screw head (30) is further protruded on the upper side end surface, the screw head (30) being used for clamping with a screwing tool, and a first transition arc surface (31) is connected between the screw head (30) and the upper side end surface.

7. Threaded connection (100) according to claim 6, wherein An end of the screw head (30) away from the upper side end surface is recessed with a clamping groove (32), and a plurality of clamping sub-grooves (321) are recessed on the inner peripheral wall of the clamping groove (32) and are spaced apart; the clamping sub-grooves (321) are arc grooves, and a second transition arc surface (322) is connected between two adjacent clamping sub-grooves (321).

8. Threaded connection (100) according to claim 7, wherein A third transition arc surface (13) is further connected between the threaded rod and the pressing surface (21).

9. Threaded connection (100) according to claim 6, wherein The application further relates to a threaded connecting piece (100) comprising any one of the threaded rods according to claims 1-11.

10. Threaded connection (100) according to claim 9, wherein ​ 11. Threaded connection (100) according to any one of claims 1-4, wherein ​ 12. A battery pack, wherein, ​