Bolt assemblies, fixing mechanisms, battery systems, and automobiles

Abstract

This application relates to a bolt assembly, a fixing mechanism, a battery system, and an automobile, belonging to the field of new energy vehicle technology. The bolt assembly includes a housing, a bolt, a compression spring, a retaining ring, a first cover plate, a first sealing ring, and a second sealing ring. The outer wall of the non-threaded section has a first external spline, the inner and outer walls of the retaining ring have a first internal spline and a second external spline, respectively, and the inner wall of the first through hole of the first cover plate has a second internal spline. The first sealing ring is located between the first cover plate and the housing, and the second sealing ring is located between the first cover plate and the non-threaded section. Using this application improves the sealing performance of the bolt assembly and prevents bolt stripping during installation, thereby extending the service life of the bolt assembly.

Description

Technical Field

[0001] This application relates to the field of new energy vehicle technology, and in particular to a bolt assembly, a fixing mechanism, a battery system, and an automobile. Background Technology

[0002] For new energy vehicles, there are currently two energy replenishment modes: charging and battery swapping. Compared to charging, battery swapping offers advantages such as rapid replenishment and lower battery wear. In battery swapping, the vehicle must be parked at a battery swapping station for battery replacement. The fixing mechanism of new energy vehicles includes bolt assemblies and nut assemblies. The servo gun can replace the battery pack by removing and installing bolts in the bolt assembly.

[0003] Currently, the sealing performance of bolt assemblies is poor. In addition, during the process of installing the battery pack onto the vehicle body, the servo gun usually directly tightens the bolts.

[0004] However, the bolt assembly has poor sealing performance, making it easy for impurities such as dust and metal shavings to enter. When installing the battery pack, the servo gun directly tightens the bolts, and the axis of rotation during tightening may deviate from the axis of the threaded hole, leading to stripping of the threads. Both of these factors can reduce the service life of the bolt assembly. Summary of the Invention

[0005] This application provides a bolt assembly, a fixing mechanism, a battery system, and a vehicle, which can solve the technical problems existing in related technologies. The technical solution is as follows:

[0006] In a first aspect, embodiments of this application provide a bolt assembly, which includes a housing, a bolt, a compression spring, a retaining ring, a first cover plate, a first sealing ring, and a second sealing ring;

[0007] The housing is used to be fixedly connected to the battery pack frame. The housing has a cylindrical structure with openings at both ends and a cylindrical cavity inside the cylindrical structure.

[0008] The bolt comprises a threaded segment, a flange portion, and a non-threaded segment connected in sequence. The threaded segment is used for threaded connection with a floating nut assembly. The diameter of the threaded segment is less than or equal to the inner diameter of a first opening of the housing, which is an opening of the housing near the threaded segment. The diameter of the flange portion is greater than the inner diameter of the first opening. The outer wall of the flange portion is in contact with the inner wall of the cylindrical cavity. The flange portion is capable of sliding within the cylindrical cavity. When the flange portion is in a limit position near the first opening, a portion of the threaded segment is located outside the first opening, and the non-threaded segment is located within the cylindrical cavity. A portion of the outer wall of the non-threaded segment has a first external spline.

[0009] The compression spring is connected to the wall surface of the flange portion away from the threaded section;

[0010] The inner wall of the locking ring has a first internal spline, which cooperates with the first external spline. The outer wall of the locking ring has a second external spline. The outer diameter of the locking ring is larger than the outer diameter of the compression spring. The locking ring can slide on the portion of the non-threaded section outer wall with the first external spline.

[0011] The first cover plate is located in the second opening of the housing and is connected to the housing. The second opening is an opening in the housing near the non-threaded section. The first cover plate has a first through hole penetrating a first surface and a second surface. The first surface is the surface of the first cover plate near the first opening, and the second surface is the surface opposite to the first surface. The inner diameter of the first through hole is larger than the diameter of the non-threaded section. The inner wall of the first through hole has a second internal spline, which mates with a second external spline.

[0012] The first sealing ring is located between the first cover plate and the housing, and is connected to the first cover plate;

[0013] The second sealing ring is located between the first through hole and the non-threaded section, and is connected to the inner wall of the first through hole.

[0014] In one possible implementation, the external thread on the outer wall of the threaded segment is a fine thread.

[0015] In one possible implementation, the first through hole includes a first hole segment and a second hole segment;

[0016] The first hole segment is located on the side of the second hole segment near the first surface. The inner wall of the first hole segment has a second internal spline. When the flange portion is located at the extreme position near the first opening, the end of the first hole segment away from the first opening is flush with the end of the first external spline away from the first opening.

[0017] The inner wall of the second hole section is a smooth wall surface, and the second sealing ring is located between the second hole section and the non-threaded section, and is connected to the inner wall of the second hole section.

[0018] In one possible implementation, the diameter of the threaded segment is the same as the diameter of the non-threaded segment.

[0019] In one possible implementation, both the first sealing ring and the second sealing ring are made of polytetrafluoroethylene (PTFE).

[0020] Secondly, embodiments of this application provide a fixing mechanism, which includes a floating nut assembly and a bolt assembly as described in the first aspect and its possible implementations.

[0021] In one possible implementation, the floating nut assembly includes a dust cover, a floating nut, and a third sealing ring;

[0022] The dust cover is used to connect with the vehicle body beam. The dust cover has a first cavity and a second cavity, and the first cavity and the second cavity are connected.

[0023] The floating nut includes a nut body and a limiting protrusion. The nut body has a cylindrical structure and a threaded through hole along its axial direction. The threaded through hole is used for threaded connection with the threaded section of the bolt in the bolt assembly. A portion of the nut body is located in the first cavity, and another portion is located in the second cavity. The limiting protrusion is located on the outer wall of the nut body and is connected to the nut body. The limiting protrusion is located in the first cavity and is capable of moving along the axial direction of the cylindrical structure within the first cavity.

[0024] The third sealing ring is located between the dust cover and the vehicle body beam, and is connected to the dust cover.

[0025] In one possible implementation, the second cavity is located on the side of the first cavity away from the bolt assembly.

[0026] In one possible implementation, when the limiting protrusion is located at an extreme position far from the second cavity, the distance from the wall of the limiting protrusion near the second cavity to the second cavity is within a first numerical range, which is two to three times the thread pitch.

[0027] In one possible implementation, the internal thread on the inner wall of the threaded through hole is a fine thread.

[0028] Thirdly, embodiments of this application provide a battery system that includes a fixing mechanism as described in the second aspect and its possible implementations.

[0029] Fourthly, embodiments of this application provide a vehicle that includes a battery system as described in the second aspect and its possible implementations.

[0030] The technical solutions provided by the embodiments of this application have at least the following beneficial effects:

[0031] The bolt assembly provided in this application includes a housing, a bolt, a compression spring, a retaining ring, a first cover plate, a first sealing ring, and a second sealing ring. The outer wall of the non-threaded section has a first external spline, the inner and outer walls of the retaining ring have a first internal spline and a second external spline, respectively, and the inner wall of the first through hole of the first cover plate has a second internal spline. The first sealing ring is located between the first cover plate and the housing, and the second sealing ring is located between the first cover plate and the non-threaded section. Thus, the first and second sealing rings improve the sealing performance of the bolt assembly, preventing impurities from entering and causing wear. Simultaneously, during the installation of the battery pack onto the vehicle body, the servo gun can push the retaining ring, which compresses the spring and moves the bolt, thereby completing the bolt installation. Since the bolt does not need to be tightened, stripping is prevented, increasing the service life of the bolt assembly.

[0032] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is a schematic diagram of the structure of a fixing mechanism shown in an embodiment of this application;

[0035] Figure 2 This is a schematic diagram of the structure of a floating nut assembly shown in an embodiment of this application;

[0036] Figure 3 This is a schematic diagram of the structure of a bolt shown in an embodiment of this application;

[0037] Figure 4 This is an exploded view of a fixing mechanism shown in an embodiment of this application.

[0038] Legend

[0039] 001. Body beam; 002. Battery pack frame;

[0040] 1. Floating nut assembly;

[0041] 11. Dust cover; 12. Floating nut; 13. Third sealing ring;

[0042] 11a, First cavity; 11b, Second cavity; 11o, Third through hole;

[0043] 121. Nut body; 122. Limiting protrusion;

[0044] 121a. Threaded through hole;

[0045] 2. Bolt assembly;

[0046] 21. Housing; 22. Bolt; 23. Compression spring; 24. Locking ring; 25. First cover plate; 26. First sealing ring; 27. Second sealing ring; 28. Fourth sealing ring; 29. ​​Second cover plate assembly;

[0047] 211. Body; 212. Shell flange; 21a. Cylindrical cavity; 21b. First opening; 21c. Second opening; 212a. Second through hole; 212o. Second threaded hole;

[0048] 221. Threaded section; 222. Flange section; 223. Non-threaded section; 223a. First external spline;

[0049] 24a, Second external spline; 24b, First internal spline;

[0050] 25m, first surface; 25n, second surface; 25e, first through hole; 25o, first threaded hole; 251e, first hole section; 252e, second hole section;

[0051] 291. Second cover plate; 292. Fifth sealing ring;

[0052] 291a, Fourth through hole; 291b, Toothed groove. Detailed Implementation

[0053] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0054] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” “third,” and similar terms used in this patent application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an” or “a” and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms “comprising” or “including” and similar terms mean that the element or object preceding “comprising” or “including” encompasses the element or object listed following “comprising” or “including” and its equivalents, and do not exclude other elements or objects. The terms “connected” or “linked” and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms “upper,” “lower,” “left,” “right,” etc., are used only to indicate relative positional relationships, and these relative positional relationships may change accordingly when the absolute position of the described object changes.

[0055] This application provides a bolt assembly 2, such as... Figure 1 As shown, the bolt assembly 2 includes a housing 21, a bolt 22, a compression spring 23, a retaining ring 24, a first cover plate 25, a first sealing ring 26, and a second sealing ring 27.

[0056] Bolt 22 includes a threaded section 221, a flange portion 222, and a non-threaded section 223.

[0057] The following is a description of each part of bolt assembly 2:

[0058] I. Shell 21

[0059] The housing 21 is a component in the bolt assembly 2 used for fixed connection with the frame 002 of the automotive battery pack.

[0060] like Figure 1 As shown, the shell 21 has a cylindrical structure with openings at both ends, and the interior of the shell 21 has a cylindrical cavity 21a.

[0061] The shell 21 can be a cylindrical structure or a prismatic structure.

[0062] The housing 21 includes a first opening 21b and a second opening 21c, as shown below. Figure 1 As shown, the housing 21 penetrates the battery pack frame 002 and is connected to the battery pack frame 002.

[0063] The first opening 21b is the opening closer to the vehicle body beam 001 among the two openings of the housing 21, and the second opening 21c is the opening farther away from the vehicle body beam 001 among the two openings of the housing 21. Both the first opening 21b and the second opening 21c are circular openings.

[0064] Optionally, the diameter of the second opening 21c can be larger than the diameter of the first opening 21b.

[0065] This improves the ease of installing the bolt 22 into the housing 21.

[0066] In practice, the outer wall of the first opening 21b of the housing 21 can be connected to the wall of the battery pack frame 002 near the vehicle body beam 001, and the outer wall of the second opening 21c of the housing 21 can be connected to the wall of the battery pack frame 002 away from the vehicle body beam 001.

[0067] Optionally, such as Figure 3 As shown, the housing 21 may include a body 211 and a housing flange 212. The body 211 has a cylindrical structure, and the housing flange 212 has a rectangular plate structure. The body 211 and the housing flange 212 are integrally formed. The housing flange 212 has a plurality of second through holes 212a in the thickness direction, i.e., in the axial direction of the body 211. The plurality of second through holes are used to mate with threaded holes on the battery pack frame 002 to fix the housing 21 to the battery pack frame 002.

[0068] For example, the number of second through holes 212a can be four, and the four second through holes 212a are distributed at the four apex positions of the housing flange 212.

[0069] II. Bolt 22

[0070] Bolt 22 is a component in bolt assembly 2 used to connect the battery pack frame 002 and the vehicle body beam 001, such as... Figure 1 As shown, bolt 22 includes a threaded section 221, a flange portion 222, and a non-threaded section 223.

[0071] Thread section 221

[0072] The threaded section 221 is the part of the bolt 22 used for threaded connection with the floating nut assembly 1.

[0073] like Figure 3 As shown, the threaded section 221 has a cylindrical structure with external threads on its outer wall. The major diameter of the external threads is less than or equal to the inner diameter of the first opening 21b.

[0074] The threaded segment 221 is at least partially located in the first opening 21b and is capable of sliding along the axis of the first opening 21b within the first opening 21b.

[0075] Optionally, the external thread on the outer wall of the threaded section 221 can be a fine thread or a round thread.

[0076] This reduces stress concentration at the root of the tooth. Furthermore, since the car vibrates during driving, the threaded connection between the threaded section 221 and the floating nut assembly 1 will be subjected to vibration loads. Setting the external thread of the threaded section 221 as a fine thread or a round thread can ensure that the threaded section 221 has good self-locking performance under vibration loads, preventing movement between the threaded section 221 and the floating nut assembly 1.

[0077] Optionally, the end of the threaded section 221 near the body beam 001 may have a chamfer.

[0078] Flange 222

[0079] Flange 222 is a component that limits the sliding movement of bolt 22 in the axial direction.

[0080] like Figure 3 As shown, the flange portion 222 is located in the cylindrical cavity 21a and is connected to the threaded section 221. The flange portion 222 has a cylindrical structure, the outer wall of the flange portion 222 is in contact with the inner wall of the cylindrical cavity 21a, and the diameter of the flange portion 222 is larger than the inner diameter of the first opening 21b.

[0081] The flange 222 can slide in the cylindrical cavity 21a. During the sliding process of the flange 222, when the flange 222 slides to the limit position close to the first opening 21b, that is, when the upper surface of the flange 222 is in contact with the wall of the housing 21 close to the first opening 21b, a part of the threaded section 221 is located outside the first opening 21b.

[0082] In this way, when the flange 222 moves to the wall of the housing 21 near the first opening 21b, it can limit the bolt 22 and prevent the bolt 22 from moving upward.

[0083] Non-threaded section 223

[0084] The non-threaded section 223 is a component that limits the rotation of bolt 22 in the direction around the axis.

[0085] like Figure 3 As shown, the non-threaded section 223 has a cylindrical structure. The non-threaded section 223 is located on the side of the flange portion 222 away from the threaded section 221 and is connected to the flange portion 222. The non-threaded section 223 is at least partially located in the cylindrical cavity 21a.

[0086] The outer wall of the non-threaded section 223 has a first external spline 223a.

[0087] In this way, the non-threaded section 223 can cooperate with the inner spline of the retaining ring 24 through the first external spline 223a to limit the rotation of the bolt 22 in the direction around the axis.

[0088] Optionally, the outer surface of the first external spline 223a may be heat-treated, such as by nitriding.

[0089] This can increase the surface hardness of the first external spline 223a and prevent the first external spline 223a from deforming.

[0090] Optionally, the diameter of the threaded section 221 can be the same as the diameter of the non-threaded section 223.

[0091] This reduces the machining difficulty of bolt 22.

[0092] Optionally, the diameter of the threaded section 221 can be a first diameter D1, the diameter of the flange 222 can be a second diameter D2, and the diameter of the non-threaded section 223 can be a third diameter D3. The first diameter D1, the second diameter D2, and the third diameter D3 can satisfy the relationship that the second diameter D2 is greater than the first diameter D1 and the third diameter D3.

[0093] In this way, while minimizing costs, the bolt 22 can be guaranteed to have high mechanical strength.

[0094] Optionally, the bolt 22 may also include a reinforcing rib located on the side of the flange portion 222 away from the threaded section 221 and connected to the flange portion 222 and the non-threaded section 223.

[0095] In one example, the flange portion 222 and the non-threaded section 223 are coaxial, the flange portion 222 is perpendicular to the non-threaded section 223, and the reinforcing rib is a right-angled triangular reinforcing rib, with the two right-angled sides of the right-angled triangular reinforcing rib connected to the flange portion 222 and the non-threaded section 223 respectively.

[0096] This reduces the machining difficulty of bolt 22 and improves the overall strength of bolt 22.

[0097] Optionally, the threaded section 221, the flange portion 222, and the non-threaded section 223 may have an integrally formed structure.

[0098] In one example, the threaded section 221, the flange 222, and the non-threaded section 223 can be formed by casting first, and then the external thread and the first external spline 223a can be machined by cutting.

[0099] This can improve the overall strength of bolt 22.

[0100] Optionally, the threaded section 221, the flange 222, and the non-threaded section 223 can be processed and formed separately, and then connected together. The connection method between the threaded section 221, the flange 222, and the non-threaded section 223 can be friction welding or arc welding. This application embodiment does not limit the connection method between the threaded section 221, the flange 222, and the non-threaded section 223.

[0101] The threaded section 221, flange 222, and non-threaded section 223 can be made of the same material, such as carbon alloy steel. Alternatively, the threaded section 221, flange 222, and non-threaded section 223 can be made of different materials, such as carbon alloy steel for the threaded section 221 and flange 222, and titanium alloy for the non-threaded section 223. This application does not limit the material of the threaded section 221, flange 222, and non-threaded section 223 in this embodiment.

[0102] III. Compression Spring 23

[0103] Compression spring 23 is a component in bolt assembly 2 used to push bolt 22 and retaining ring 24.

[0104] like Figure 1 As shown, one end of the compression spring 23 is connected to the wall surface of the flange portion 222 away from the threaded section 221.

[0105] In practice, when the flange 222 is in the extreme position close to the first opening 21b, when the compression spring 23 is in its natural state, the other end of the compression spring 23 is located on the non-threaded section 223 with the first external spline 223a.

[0106] The connection between the compression spring 23 and the flange 222 can be welded or snap-fitted. This application embodiment does not limit the connection method between the compression spring 23 and the flange 222.

[0107] In one example, the flange portion 222 has a snap-fit ​​groove on the wall away from the threaded section 221, and the compression spring 23 has a snap-fit ​​protrusion at one end near the flange portion 222. The snap-fit ​​protrusion and the snap-fit ​​groove cooperate to realize a detachable connection between the compression spring 23 and the flange portion 222.

[0108] In one example, the compression spring 23 is made of high-carbon steel.

[0109] IV. Positioning Ring 24

[0110] like Figure 1 As shown, the locking ring 24 has a ring structure, the outer diameter of the locking ring 24 is larger than the outer diameter of the compression spring 23, the inner wall of the locking ring 24 has a first internal spline 24b, and the outer wall of the locking ring 24 has a second external spline 24a.

[0111] The first internal spline 24b is coupled with the first external spline 223a.

[0112] The locking ring 24 can slide on the portion of the outer wall of the non-threaded section 223 that has the first external spline 223a.

[0113] In implementation, the locking ring 24 can achieve a sliding connection with the non-threaded section 223 through the engagement of the first internal spline 24b and the first external spline 223a. When the locking ring 24 is not rotated, it can rotate around its axis, and correspondingly, the non-threaded section 223 can also rotate around its axis. When the locking ring 24 is rotated, it cannot rotate around its axis, and correspondingly, the non-threaded section 223 also cannot rotate around its axis.

[0114] V. First cover plate 25

[0115] The first cover plate 25 is a component in the bolt assembly 2 used to limit the rotation of the locking ring 24.

[0116] like Figure 1 As shown, the first cover plate 25 has a rectangular plate structure and a first through hole 25e that penetrates the first surface 25m and the second surface 25n. The first cover plate 25 is located in the second opening 21c of the housing 21 and is connected to the housing 21. The inner wall of the first through hole 25e has a second internal spline 25b.

[0117] Among them, the first surface 25m is the surface of the first cover plate 25 that is close to the first opening 21b, the second surface 25n is the surface opposite to the first surface 25m, the inner diameter of the first through hole 25e is larger than the diameter of the non-threaded section 223, and the second internal spline 25b is engaged with the second external spline 24a.

[0118] In practice, the first through hole 25e can be used to accommodate the locking ring 24. When the locking ring 24 is located in the first through hole 25e, due to the cooperation between the second internal spline 25b and the second external spline 24a, the first cover plate 25 limits the rotation of the locking ring 24 around its axis. When the locking ring 24 is located outside the first through hole 25e, the first cover plate 25 does not limit the rotation of the locking ring 24, and the locking ring 24 can rotate around its axis.

[0119] like Figure 4 As shown, the first cover plate 25 has a plurality of first threaded holes 25o in the thickness direction (i.e., in the direction penetrating the first surface 25m and the second surface 25n), and the housing flange 212 of the housing 21 has a plurality of second threaded holes 212o.

[0120] In this way, the first cover plate 25 can be detachably connected to the housing 21 through the cooperation between the first threaded hole 25o, the second threaded hole 212o and the connecting bolt.

[0121] VI. First sealing ring 26 and second sealing ring 27

[0122] The first sealing ring 26 and the second sealing ring 27 are components used to seal the connection of the bolt assembly 2.

[0123] like Figure 1 As shown, the first sealing ring 26 is located between the first cover plate 25 and the housing 21, and is connected to the first cover plate 25. The second sealing ring 27 is located between the first through hole 25e and the non-threaded section 223, and is connected to the inner wall of the first through hole 25e.

[0124] Both the first sealing ring 26 and the second sealing ring 27 have annular structures and are elastic elements.

[0125] Optionally, the first sealing ring 26 and the second sealing ring 27 may be made of the same material, such as polytetrafluoroethylene.

[0126] In practice, the wall surface of the first cover plate 25 that is in contact with the housing 21 may have a sealing ring mounting groove, and the first sealing ring 26 may be set in the sealing ring mounting groove, thereby sealing the gap between the housing 21 and the first cover plate 25 and preventing dust, metal shavings and other impurities from entering the bolt assembly 2 through the gap between the housing 21 and the first cover plate 25.

[0127] The outer wall of the second sealing ring 27 and the inner wall of the first through hole 25e can be interference-fitted, and the inner wall of the second sealing ring 27 and the outer wall of the non-threaded section 223 can be interference-fitted.

[0128] In this way, the second sealing ring 27 can seal the gap between the first cover plate 25 and the non-threaded section 223, preventing dust, metal shavings and other impurities from entering the bolt assembly 2 through the gap between the first cover plate 25 and the non-threaded section 223.

[0129] The following describes some optional structural features of bolt assembly 2:

[0130] Structural feature 1: The first through hole 25e can be a stepped through hole.

[0131] like Figure 3 As shown, the first through hole 25e includes a first hole section 251e and a second hole section 252e, and the inner diameter of the first hole section 251e is larger than the inner diameter of the second hole section 252e.

[0132] The first hole segment 251e is located on the side of the second hole segment 252e near the first surface 25m, and the inner wall of the first hole segment 251e has a second internal spline 25b.

[0133] When the flange 222 is in the extreme position close to the first opening 21b, the end of the first hole section 251e away from the first opening 21b is flush with the end of the first external spline 223a away from the first opening 21b.

[0134] The inner wall of the second hole section 252e is a smooth wall surface. The second sealing ring 27 is located between the second hole section 252e and the non-threaded section 223, and is connected to the inner wall of the second hole section 252e.

[0135] In practice, the first hole section 251e is used to accommodate the locking ring 24 and to rotate and limit the locking ring 24. The wall surface of the second hole section 252e is a smooth wall surface. When the flange 222 is in the extreme position close to the first opening 21b, the wall surface of the non-threaded section 223 in the second hole section 252e is also a smooth wall surface.

[0136] This improves the fit between the second sealing ring 27 and the gap.

[0137] Structural feature 2: Bolt assembly 2 may also include a fourth sealing ring 28.

[0138] like Figure 3 As shown, a sealing ring mounting groove is provided on the wall surface of the first hole section 251e that is parallel to the first surface 25m. The fourth sealing ring 28 is located in the sealing ring mounting groove and is connected to the first cover plate 25.

[0139] In this way, the fourth sealing ring 28 can seal the gap between the first cover plate 25 and the retaining ring 24, preventing dust, metal shavings and other impurities from entering the bolt assembly 2 through the gap between the first cover plate 25 and the retaining ring 24.

[0140] Structural feature 3: Bolt assembly 2 may also include a second cover plate assembly 29.

[0141] like Figure 4 As shown, the second cover plate assembly 29 includes a second cover plate 291 and a fifth sealing ring 292.

[0142] Second cover plate 291

[0143] The second cover plate 291 is a component used to separate the body beam 001 and the battery pack frame 002.

[0144] like Figure 4 As shown, the second cover plate 291 has a circular plate structure with a fourth through hole 291a at its axial position. The inner wall of the fourth through hole 291a is in contact with the outer wall of the first opening 21b.

[0145] The surface of the second cover plate 291 near the sealing ring has a mounting groove.

[0146] Optionally, the edge of the second cover plate 291 may have multiple toothed grooves 291b.

[0147] This improves the ease of assembling and disassembling the second cover plate 291 from the first opening 21b.

[0148] Fifth sealing ring 292

[0149] The fifth sealing ring 292 is a component used to seal the second cover plate 291 and the second cover plate 291.

[0150] like Figure 1 As shown, the fifth sealing ring 292 is located between the second cover plate 291 and the vehicle body beam 001, and is connected to the second cover plate 291.

[0151] The fifth sealing ring 292 has a circular structure and is an elastic element.

[0152] Optionally, the fifth sealing ring 292 can be made of polytetrafluoroethylene.

[0153] In this way, the production cost of the fifth sealing ring 292 can be kept low while ensuring that the fifth sealing ring 292 has a long service life.

[0154] In practice, the wall surface of the second cover plate 291 that is in contact with the body beam 001 may have a sealing ring mounting groove, and the fifth sealing ring 292 may be set in the sealing ring mounting groove, thereby sealing the gap between the second cover plate 291 and the body beam 001 and preventing dust, metal shavings and other impurities from entering the bolt assembly 2 through the gap between the second cover plate 291 and the body beam 001.

[0155] The bolt assembly 2 provided in this embodiment includes a housing 21, a bolt 22, a compression spring 23, a retaining ring 24, a first cover plate 25, a first sealing ring 26, and a second sealing ring 27. The outer wall of the non-threaded section 223 has a first external spline 223a. The inner and outer walls of the retaining ring 24 have a first internal spline 24b and a second external spline 24a, respectively. The inner wall of the first through hole 25e of the first cover plate 25 has a second internal spline 25b. The first sealing ring 26 is located between the first cover plate 25 and the housing 21, and the second sealing ring 27 is located between the first through hole 25e and the non-threaded section 223. Thus, the first sealing ring 26 and the second sealing ring 27 can improve the sealing performance of the bolt assembly 2 and prevent impurities from entering the bolt assembly 2. Meanwhile, during the installation of the battery pack onto the vehicle body, the servo gun can push the locking ring 24, which in turn compresses the spring 23, thereby moving the bolt 22 to complete the installation without the need to tighten the bolt 22. This prevents stripping and improves the service life of the bolt assembly.

[0156] This application provides a fixing mechanism, which includes a floating nut assembly 1 and a bolt assembly 2 for mounting.

[0157] The floating nut assembly 1 includes a dust cover 11, a floating nut 12, and a third sealing ring 13.

[0158] The dust cover 11 is used to connect with the vehicle body beam 001, and the floating nut 12 includes a nut body 121 and a limiting protrusion.

[0159] The following is a description of each part of the floating nut assembly 1:

[0160] 1. Dust cover 11

[0161] The dust cover 11 is a component in the floating nut assembly 1 used to limit the floating nut 12.

[0162] like Figure 1 As shown, the dust cover 11 is located on the side of the body beam 001 away from the battery pack frame 002 and is connected to the body beam 001.

[0163] like Figure 2 As shown, the dust cover 11 has multiple third through holes 11o perpendicular to the body beam 001. The third through holes 11o are used to mate with bolts and threaded holes on the body beam 001 to achieve a detachable connection between the dust cover 11 and the body beam 001.

[0164] like Figure 2As shown, the dust cover 11 has a first cavity 11a and a second cavity 11b. The first cavity 11a and the second cavity 11b are connected. Both the first cavity 11a and the second cavity 11b are rectangular plate-shaped cavities. In the cross-sectional direction perpendicular to the axis of the third through hole 11o, the cross-sectional area of ​​the first cavity 11a is larger than that of the second cavity 11b.

[0165] Optionally, the second cavity 11b may be located on the side of the first cavity 11a away from the bolt assembly 2.

[0166] II. Floating Nut 12

[0167] The floating nut 12 is a component in the floating nut assembly 1 used for threaded connection with the bolt 22 in the bolt assembly 2.

[0168] like Figure 2 As shown, the floating nut 12 includes a nut body 121 and a limiting protrusion 122.

[0169] Nut body 121

[0170] The nut body 121 has a cylindrical structure with a threaded through hole 121a along the axial direction of the cylindrical structure. The threaded through hole 121a is used to thread the bolt 22 in the bolt assembly 2 with the threaded section 221. A part of the nut body 121 is located in the first cavity 11a and the other part is located in the second cavity 11b.

[0171] Optionally, the external thread on the outer wall of the threaded section 221 can be a fine thread or a round thread.

[0172] This reduces stress concentration at the root of the tooth. Furthermore, since the car vibrates during driving, the threaded connection between the threaded section 221 and the floating nut assembly 1 will be subjected to vibration loads. Setting the external thread of the threaded section 221 as a fine thread or a round thread can ensure that the threaded section 221 has good self-locking performance under vibration loads, preventing movement between the threaded section 221 and the floating nut assembly 1.

[0173] In practice, when the nut body 121 is located at its extreme position close to the vehicle body beam 001, there is a gap between the surface of the nut body 121 away from the vehicle body beam 001 and the wall surface of the second cavity 11b away from the vehicle body beam 001.

[0174] Optionally, the distance of the aforementioned gap can be within a first numerical range, which is from two times the thread pitch to three times the thread pitch.

[0175] In this way, the nut body 121 can float in the first cavity 11a and the second cavity 11b.

[0176] Limiting protrusion 122

[0177] The limiting protrusion 122 has a rectangular plate-like structure. The limiting protrusion 122 is located on the outer wall of the nut body 121 and is connected to the nut body 121. The limiting protrusion 122 is located in the first cavity 11a and can move along the axial direction of the cylindrical structure in the first cavity 11a.

[0178] In practice, the limiting protrusion 122 is located in the first cavity 11a, and the side wall of the limiting protrusion 122 is in contact with the inner wall of the first cavity 11a. The inner wall of the first cavity 11a can rotate and limit the limiting protrusion 122.

[0179] Optionally, when the limiting protrusion 122 is located at an extreme position far away from the second cavity 11b, the distance from the wall of the limiting protrusion 122 near the second cavity 11b to the second cavity 11b is within a first numerical range, which is two times the thread pitch to three times the thread pitch.

[0180] In this way, the limiting protrusion 122 can float in the first cavity 11a, thereby eliminating the influence of the installation tolerance between the nut body 121 and the threaded portion 221.

[0181] III. Third sealing ring 13

[0182] The third sealing ring 13 is a component used to seal the connection of the floating nut assembly 1.

[0183] like Figure 1 As shown, the third sealing ring 13 is located between the dust cover 11 and the body beam 001, and is connected to the dust cover 11.

[0184] The third sealing ring 13 has a circular structure and is an elastic element.

[0185] Optionally, the third sealing ring 13 can be made of polytetrafluoroethylene.

[0186] In this way, the production cost of the third sealing ring 13 can be kept low while ensuring that the third sealing ring 13 has a long service life.

[0187] In practice, the wall surface of the dust cover 11 that is in contact with the body beam 001 may have a sealing ring mounting groove, and the third sealing ring 13 may be set in the sealing ring mounting groove, thereby sealing the gap between the dust cover 11 and the body beam 001 and preventing dust, metal shavings and other impurities from entering the floating nut assembly 1 through the gap between the dust cover 11 and the body beam 001.

[0188] This application provides a battery system that includes the aforementioned fixing mechanism.

[0189] This application provides an automobile that includes the battery system described above.

[0190] The above description is merely an optional embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A bolt assembly (2), characterized in that, The bolt assembly (2) includes a housing (21), a bolt (22), a compression spring (23), a retaining ring (24), a first cover plate (25), a first sealing ring (26), and a second sealing ring (27); The housing (21) is used to be fixedly connected to the battery pack frame (002). The housing (21) has a cylindrical structure with openings at both ends and a cylindrical cavity (21a) inside the cylindrical structure. The bolt (22) comprises a threaded segment (221), a flange (222), and a non-threaded segment (223) connected in sequence. The threaded segment (221) is used for threaded connection with the floating nut assembly (1). The diameter of the threaded segment (221) is less than or equal to the inner diameter of the first opening (21b) of the housing (21), the first opening (21b) being the opening of the housing (21) near the threaded segment (221). The diameter of the flange (222) is greater than the inner diameter of the first opening (21b). The outer wall of the flange (222) is in contact with the inner wall of the cylindrical cavity (21a). The flange (222) is able to slide in the cylindrical cavity (21a). When the flange (222) is in an extreme position close to the first opening (21b), a portion of the threaded section (221) is outside the first opening (21b), and the unthreaded section (223) is located in the cylindrical cavity (21a). A portion of the outer wall of the unthreaded section (223) has a first external spline (223a). The compression spring (23) is connected to the wall of the flange (222) away from the threaded section (221); The inner wall of the locking ring (24) has a first internal spline (24b), which cooperates with the first external spline (223a). The outer wall of the locking ring (24) has a second external spline (24a). The outer diameter of the locking ring (24) is larger than the outer diameter of the compression spring (23). The locking ring (24) can slide on the portion of the non-threaded section (223) with the first external spline (223a) on its outer wall. The first cover plate (25) is located in the second opening (21c) of the housing (21) and is connected to the housing (21). The second opening (21c) is the opening in the housing (21) near the non-threaded section (223). The first cover plate (25) has a first through hole (25e) penetrating the first surface (25m) and the second surface (25n). The first surface (25m) is the surface in the first cover plate (25) near the first opening (21b). The second surface (25n) is the surface opposite to the first surface (25m). The inner diameter of the first through hole (25e) is larger than the diameter of the non-threaded section (223). The inner wall of the first through hole (25e) has a second internal spline (25b). The second internal spline (25b) cooperates with the second external spline (24a). The first sealing ring (26) is located between the first cover plate (25) and the housing (21), and is connected to the first cover plate (25); The second sealing ring (27) is located between the first through hole (25e) and the non-threaded section (223) and is connected to the inner wall of the first through hole (25e).

2. The bolt assembly (2) according to claim 1, characterized in that, The external thread on the outer wall of the threaded section (221) is a fine thread.

3. The bolt assembly (2) according to claim 1, characterized in that, The first through hole (25e) includes a first hole section (251e) and a second hole section (252e); The first hole segment (251e) is located on the side of the second hole segment (252e) near the first surface (25m). The inner wall of the first hole segment (251e) has a second internal spline (25b). When the flange portion (222) is located at the extreme position near the first opening (21b), the end of the first hole segment (251e) away from the first opening (21b) is flush with the end of the first external spline (223a) away from the first opening (21b). The inner wall of the second hole section (252e) is a smooth wall surface, and the second sealing ring (27) is located between the second hole section (252e) and the non-threaded section (223), and is connected to the inner wall of the second hole section (252e).

4. The bolt assembly (2) according to claim 1, characterized in that, The diameter of the threaded section (221) is the same as the diameter of the non-threaded section (223).

5. The bolt assembly (2) according to any one of claims 1 to 4, characterized in that, Both the first sealing ring (26) and the second sealing ring (27) are made of polytetrafluoroethylene.

6. A fixing mechanism, characterized in that, The fixing mechanism includes a floating nut assembly (1) and a bolt assembly (2) as described in any one of claims 1-5.

7. The fixing mechanism according to claim 6, characterized in that, The floating nut assembly (1) includes a dust cover (11), a floating nut (12), and a third sealing ring (13); The dust cover (11) is used to connect with the vehicle body beam (001). The dust cover (11) has a first cavity (11a) and a second cavity (11b) inside, and the first cavity (11a) and the second cavity (11b) are connected. The floating nut (12) includes a nut body (121) and a limiting protrusion (122). The nut body (121) has a cylindrical structure and a threaded through hole (121a) in the axial direction of the cylindrical structure. The threaded through hole (121a) is used to thread the bolt (22) in the bolt assembly (2) with the threaded segment (221). A part of the nut body (121) is located in the first cavity (11a) and another part is located in the second cavity (11b). The limiting protrusion (122) is located on the outer wall of the nut body (121) and connected to the nut body (121). The limiting protrusion (122) is located in the first cavity (11a) and can move in the first cavity (11a) along the axial direction of the cylindrical structure. The third sealing ring (13) is located between the dust cover (11) and the vehicle body beam (001), and is connected to the dust cover (11).

8. The fixing mechanism according to claim 7, characterized in that, The second cavity (11b) is located on the side of the first cavity (11a) away from the bolt assembly (2).

9. The fixing mechanism according to claim 8, characterized in that, When the limiting protrusion (122) is located at an extreme position far away from the second cavity (11b), the distance from the wall of the limiting protrusion (122) near the second cavity (11b) to the second cavity (11b) is within a first numerical range, which is two to three times the thread pitch.

10. The fixing mechanism according to claim 7, characterized in that, The internal thread on the inner wall of the threaded through hole (121a) is a fine thread.

11. A battery system, characterized in that, The battery system includes a fixing mechanism as described in any one of claims 6-10.

12. A car, characterized in that, The vehicle includes the battery system as described in claim 11.

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