Fuel cell end plate packaging structure and packaging method

Abstract

The present application belongs to the technical field of fuel cell stack packaging, and particularly relates to a fuel cell end plate packaging structure and a packaging method. The present application comprises a shell, an insulating plate, a floating end plate and a telescopic packaging part. The shell is placed outside the core, and a plurality of connecting through holes are arranged on the top end face of the shell. The upper end of the connecting through hole is higher than the top end face of the shell. The insulating plate is placed on the top end face of the core. The floating end plate is placed on the insulating plate. The telescopic packaging part is provided with multiple groups. The bottom end face of each group of the telescopic packaging part is connected to the top end face of the floating end plate. The top end of each group of the telescopic packaging part is connected to the connecting through hole of the top end of the shell. The number of groups of the telescopic packaging part is the same as the number of the connecting through holes of the top end of the shell. The present application realizes the interlocking between the components by sequentially screwing in the packaging components, thereby achieving the core packaging and the interlocking between the components, so as to inhibit the loosening of the threaded pair and improve the reliability of the packaging components. The present application effectively solves the loosening failure problem of the heavy load threaded pair and the risk of failure not being easily detected.

Description

Technical Field

[0001] This invention belongs to the field of fuel cell stack packaging technology, specifically relating to a fuel cell endplate packaging structure and packaging method. Background Technology

[0002] As a special structural product composed of multiple stacked single cells, fuel cell stacks are often encapsulated using a fixed shell, floating end plates, disc springs, and top plate to ensure the stability of the stack structure and provide necessary protection. This allows for the adaptation of the stack size to fluctuations and provides stable encapsulation force.

[0003] To achieve the transfer of encapsulation force from the floating endplate, disc spring assembly, and top plate to the housing, existing technologies mostly employ threaded connections between the housing and top plate. This structure can both transfer the encapsulation load and accommodate the dimensional fluctuations of stacked cores from different batches. However, threaded connections inevitably suffer from loosening issues, especially under continuous vibration and impact conditions during fuel cell operation, necessitating consideration of this load transfer structure's loosening problem. This failure issue is located inside the fuel cell encapsulation, making it difficult to detect and perceive, and its impact on fuel cell performance and stability is significant, while also posing a safety risk of hydrogen leakage in case of core failure. Existing conventional threaded anti-loosening methods cannot simultaneously meet the requirements of structural simplicity and ease of assembly and disassembly. Summary of the Invention

[0004] This invention provides a fuel cell endplate packaging structure and packaging method. Its purpose is to provide a fuel cell endplate packaging structure and packaging method that can solve the problem of back-loosening failure during load transmission by threaded pairs in the prior art, thereby improving the reliability, stability, and service life of fuel cell stacks.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A fuel cell endplate packaging structure for packaging a fuel cell stack, comprising:

[0007] The shell is placed outside the core. Multiple connecting through holes are provided on the top end face of the shell, and the upper outer edge of the connecting through holes is higher than the top end face of the shell.

[0008] Insulating plate, the insulating plate is placed on the top surface of the core;

[0009] Floating end plate, the floating end plate is placed on the insulating plate;

[0010] The telescopic encapsulation section has multiple sets, and the bottom end face of each set of telescopic encapsulation sections is connected to the top end face of the floating end plate; the top end of each set of telescopic encapsulation sections is connected to the connecting through hole at the top end of the housing; the number of sets of telescopic encapsulation sections is the same as the number of connecting through holes at the top end of the housing.

[0011] The plurality of connecting through holes are evenly arranged on the top surface of the housing; a first countersunk and a second countersunk are provided on the inner wall of each connecting through hole from top to bottom; a fourth threaded pair external thread is provided on the upper outer wall of the connecting through hole; a second threaded pair internal thread is provided on the inner wall between the first countersunk and the second countersunk; a first threaded pair internal thread is provided on the inner wall between the second countersunk and the bottom of the connecting through hole.

[0012] The upper surface of the floating end plate is provided with a plurality of slots for connecting the telescopic encapsulation part, and the slots are provided with a first annular protrusion for engaging the telescopic encapsulation part; the height of the first annular protrusion is greater than the thickness of the floating end plate surface.

[0013] The telescopic encapsulation unit includes a disc spring assembly, a disc spring top plate, a top plate nut, a lock nut, a fixed shaft, and a flange cover. The disc spring assembly is connected to the upper surface of the floating end plate. The top of the disc spring assembly is connected to the top plate nut via the disc spring top plate. The upper side wall of the top plate nut is threadedly connected to the connecting through hole on the housing. The top of the top plate nut is threadedly connected to the lock nut. The center of the lock nut is vertically threaded to the fixed shaft. The flange cover is threadedly connected to the outer side wall of the connecting through hole on the housing and contacts the top of the fixed shaft.

[0014] The disc spring top plate has a frustum-shaped structure; circular grooves are opened at the center of its top and bottom, and the diameter of the top circular groove is smaller than that of the bottom circular groove; a second annular protrusion is provided at the center of the bottom circular groove; a disc spring assembly is provided between the outer edge of the bottom circular groove and the floating end plate; the second annular protrusion is engaged with the floating end plate; the top circular groove is used to engage the top plate nut.

[0015] The top plate nut is a cylinder with a through hole in the center; a fourth tightening mechanism is provided on the inner side wall of the top of the through hole; a snap-fit ​​boss is provided on the outer side wall of the lower part of the top plate nut; and a first threaded pair external thread is provided on the outer side wall of the top plate nut above the snap-fit ​​boss.

[0016] The lock nut is a disc-shaped structure with a central through hole; the outer wall of the lock nut is provided with a second threaded external thread; the upper side wall of the through hole is provided with a third tightening mechanism for tightening with a fixed torque and for tightening and loosening the lock nut; the lower side wall of the through hole is provided with a third threaded internal thread for connecting with the lower thread of the fixed shaft after insertion; the fixed shaft is an integral structure composed of a shaft body and a shaft shoulder; the shaft shoulder is disc-shaped, with its center located at the top of the shaft body, and a second tightening mechanism for tightening the shaft body is provided at the center of its top; the shaft body is cylindrical, and the outer wall of the shaft body is provided with a third threaded external thread for connecting with the lock nut.

[0017] The flange cover has a disc-shaped structure with a groove at the bottom. The inner wall of the groove has a fourth threaded internal thread for connecting with the housing. The outer wall of the flange cover has a first tightening mechanism for screwing to control the locking of the fixed shaft's degree of freedom.

[0018] The disc spring top plate has a frustum-shaped structure; circular grooves are respectively opened at the center of its top and bottom, and the diameter of the top circular groove is smaller than the diameter of the bottom circular groove; a second annular protrusion is provided at the center of the bottom circular groove; a disc spring assembly is provided between the outer edge of the bottom circular groove and the floating end plate; the second annular protrusion is engaged with the floating end plate; the top circular groove is used to engage the top plate nut; the top plate nut is a cylinder with a through hole in the center; a fourth tightening mechanism is provided on the inner side wall of the top of the through hole; a engaging boss is provided on the outer side wall of the lower part of the top plate nut; a first threaded pair external thread is provided on the outer side wall of the top plate nut above the engaging boss; the anti-loosening nut is a disc-shaped structure with a through hole in the center; a second threaded pair external thread is provided on the outer side wall of the anti-loosening nut; the upper part of the through hole The side wall is provided with a third tightening mechanism for tightening with a constant torque and for tightening and loosening the anti-loosening nut; the lower side wall of the through hole is provided with a third threaded internal thread for connecting with the lower thread of the fixed shaft after insertion; the fixed shaft is an integral structure composed of a shaft body and a shaft shoulder; the shaft shoulder is disc-shaped, with its center located at the top of the shaft body, and a second tightening mechanism for tightening the shaft body is provided at the center of its top; the shaft body is cylindrical, and a third threaded external thread for connecting with the anti-loosening nut is provided on its outer side wall; the flange cover is a disc-shaped structure with a groove at its lower part, and a fourth threaded internal thread for connecting with the housing is provided on the inner side wall of the groove; a first tightening mechanism for screwing to control the degree of freedom of the fixed shaft is provided on the outer side wall of the flange cover.

[0019] A method for packaging a fuel cell endplate encapsulation structure, comprising the following steps:

[0020] Step 1: The top plate nut is connected to the housing via the first threaded pair;

[0021] Step 2: The lock nut is connected to the housing and the fixed shaft respectively through the second thread pair and the third thread pair;

[0022] Step 3: The flange cover is connected and fastened to the housing through the fourth threaded joint, and the shoulder of the fixed shaft is fixed in the groove formed by the flange cover and the housing.

[0023] Beneficial effects:

[0024] 1. This invention utilizes the interlocking characteristic of opposite-direction thread pairs to achieve interlocking between packaging components, thereby suppressing loosening of the thread pairs and improving the reliability of the packaging components.

[0025] 2. This invention effectively solves the problem of loosening failure of heavy-load threaded pairs and the risk of failure that is not easily detected by multiple self-locking and interlocking mechanisms.

[0026] 3. The present invention can determine the overall structure by observing the state of the external, non-load-bearing structural components, making it easy to maintain.

[0027] 4. The multi-layer self-locking and interlocking structure of the present invention ensures that the failure of the outer structure does not affect the function of the internal structure. When the components are completed, the internal structure is suppressed by self-locking and the risk of failure is extremely low, resulting in good overall structural robustness.

[0028] 5. The anti-loosening structure of this invention is connected by a standard threaded pair, which has good machinability and can be disassembled and assembled multiple times.

[0029] 6. This invention utilizes some components of existing packaging solutions, saving costs and resulting in a compact structure.

[0030] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a cross-sectional view of the structure of the present invention.

[0033] Figure 2 This is a detailed three-dimensional structural diagram of the top plate nut in this invention.

[0034] Figure 3 This is a cross-sectional view of the top plate nut in this invention.

[0035] Figure 4 This is a detailed structural diagram of the anti-loosening nut in this invention.

[0036] Figure 5 This is a detailed structural diagram of the fixed shaft in this invention.

[0037] Figure 6 This is a detailed structural diagram of the flange cover in this invention.

[0038] Figure 7 This is a detailed structural diagram of the shell in this invention.

[0039] Figure 8 and Figure 9 This is a partial schematic diagram of the locking state of two different specifications of fuel cells according to the present invention.

[0040] Figure 10 This is an exploded view of the present invention.

[0041] Figure 11 This is a schematic diagram of the core preloading of the present invention.

[0042] Figure 12 This is a schematic diagram of the pressure bar structure in this invention.

[0043] Figure 13 This is a schematic diagram of the tightening tool in this invention.

[0044] Figure 14 This is a cross-sectional view of the floating end plate in this invention.

[0045] Figure 15 This is a top view of the floating end plate in this invention.

[0046] Figure 16 This is a schematic diagram of the disc spring top plate in this invention.

[0047] In the diagram: 1. Floating end plate; 2. Disc spring assembly; 3. Disc spring top plate; 4. Top plate nut; 5. Locking nut; 6. Fixed shaft; 7. Flange cover; 8. Housing; 9. Insulating plate; 10. Core; 11. Tightening tool; 12. Pressure bar; 13. Internal thread of the first thread pair; 14. Internal thread of the second thread pair; 15. External thread of the third thread pair; 16. External thread of the fourth thread pair; 17. First contact surface; 18. Second contact surface; 19. First countersunk platform; 20. Second countersunk platform; 21. Internal thread of the fourth thread pair; 22. First tightening... 23. Shoulder; 24. Second tightening mechanism; 25. External thread of the second thread pair; 26. Internal thread of the third thread pair; 27. Third tightening mechanism; 28. External thread of the first thread pair; 29. ​​Through hole; 30. Fourth tightening mechanism; 31. First thread pair; 32. Second thread pair; 33. Third thread pair; 34. Fourth thread pair; 35. Fifth tightening mechanism; 36. Tightening boss; 37. Groove; 38. First annular protrusion; 39. Second annular protrusion; 40. Snap-fit ​​boss; 41. Disc spring top plate guide hole. Detailed Implementation

[0048] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0049] Example 1:

[0050] according to Figures 1-16 The diagram shows a fuel cell endplate encapsulation structure for encapsulating the fuel cell stack 10, comprising:

[0051] Shell 8 is placed outside core 10. Multiple connecting through holes are provided on the top end face of shell 8. The upper outer edge of the connecting through holes is higher than the top end face of shell 8.

[0052] Insulating plate 9 is placed on the top surface of core 10;

[0053] Floating end plate 1, which is placed on insulating plate 9;

[0054] The telescopic encapsulation part is provided in multiple sets. The bottom end face of each set of telescopic encapsulation parts is connected to the top end face of the floating end plate 1. The top end of each set of telescopic encapsulation parts is connected to the connecting through hole at the top end of the housing 8. The number of sets of telescopic encapsulation parts is the same as the number of connecting through holes at the top end of the housing 8.

[0055] The core 10 is a component formed by stacking individual cells, serving as the carrier for the chemical reaction in the fuel cell. In practical use, this invention achieves locking of the degrees of freedom of each encapsulation component through the reasonable threaded connection matching between the housing 8, the insulating plate 9, the floating end plate 1, and the telescopic encapsulation part, and through the interlocking effect of the multiple threaded pairs of the encapsulation components between the core 10 and the housing 8. This, in turn, achieves the anti-loosening effect of the threaded connection pairs, effectively improving the stability and reliability of the fuel cell and increasing its service life.

[0056] In this embodiment, the insulating plate 9 is made of insulating material and serves as insulation between structural components such as the core 10 and the shell 8. This embodiment employs a separate design for the insulating plate 9, which can be integrated with the floating end plate 1, simultaneously fulfilling both the insulating function of the insulating plate 9 and the load-distributing function of the floating end plate 1.

[0057] In this embodiment, the housing 8 serves as the encapsulation structure for the core 10, providing the encapsulation load force and stable and reliable internal environment required for the operation of the core 10.

[0058] In some embodiments, a plurality of connecting through holes on the housing 8 are evenly arranged on the top surface of the housing 8; a first countersunk 19 and a second countersunk 20 are provided from top to bottom on the inner sidewall of each connecting through hole; a fourth threaded pair external thread 16 is provided on the upper outer sidewall of the connecting through hole; a second threaded pair internal thread 14 is provided on the inner sidewall between the first countersunk 19 and the second countersunk 20; a first threaded pair internal thread 13 is provided on the inner sidewall between the second countersunk 20 and the bottom end of the connecting through hole.

[0059] The housing 8 provides the necessary mounting structure to enable the installation and fastening of the telescopic encapsulation part, and to enable the core 10 encapsulation load to be transferred from the telescopic encapsulation part to the housing 8.

[0060] In some embodiments, the upper surface of the floating end plate 1 is provided with a plurality of grooves 37 for connecting the telescopic encapsulation part as an installation platform for the disc spring assembly 2, providing an installation and load transfer plane for the disc spring assembly 2, and uniformly transferring the encapsulation load transmitted by the disc spring assembly 2 to the floating end plate 1; the grooves 37 are provided with a first annular protrusion 38 for engaging the telescopic encapsulation part; the first annular protrusion 38 serves as a guide post for the disc spring assembly 2, providing limiting guidance for the disc spring assembly 2 during compression deformation, preventing misalignment during deformation; the interior of the first annular protrusion 38 is a disc spring top plate guide hole 41, providing guidance for the disc spring top plate 3, and providing limiting when the disc spring top plate 3 moves up and down, preventing misalignment during load transfer; the height of the first annular protrusion 38 is greater than the thickness of the floating end plate 1. The floating end plate 1 provides installation and guidance functions for the disc spring assembly 2 in the telescopic encapsulation part, and can uniformly distribute the load of the disc spring assembly 2 to the entire cross-section of the core 10. In practical applications, the floating endplate 1 can be a metal structure or a non-metallic structure with sufficient strength. In this embodiment, the non-metallic structure uses a composite material of polyphenylene sulfide (PPS) filled with a certain proportion of glass fiber, epoxy resin, and glass fiber laminate, or a composite injection-molded material of PPS filled with glass fiber and aluminum alloy. In practical applications, different fuel cell stack designs vary, so the non-metallic structural materials used also differ; some non-metallic structural materials do not contain glass fiber, while others contain 30% or 40% glass fiber by mass; typically, a mixture of PPS and 40% glass fiber by mass is chosen.

[0061] In some embodiments, the telescopic encapsulation part includes a disc spring assembly 2, a disc spring top plate 3, a top plate nut 4, a lock nut 5, a fixed shaft 6, and a flange cover 7; the disc spring assembly 2 is connected to the upper surface of the floating end plate 1; the top end of the disc spring assembly 2 is connected to the top plate nut 4 through the disc spring top plate 3; the upper side wall of the top plate nut 4 is threadedly connected to the connecting through hole on the housing 8; the top of the top plate nut 4 is threadedly connected to the lock nut 5; the center of the lock nut 5 is vertically threadedly connected to the fixed shaft 6; the flange cover 7 is threadedly connected to the outer side wall of the connecting through hole on the housing 8 and contacts the top end of the fixed shaft 6.

[0062] The disc spring assembly 2 is positioned between the core 10 and the housing 8, providing a stable encapsulation force to the fuel cell stack through deformation. In practical applications, the disc spring assembly 2 can use standard disc springs or non-standard customized disc springs, combined in one or more sets, in the same direction or opposite directions. This solution only uses one set of disc springs for demonstration; different product structures can also be adapted by using different disc spring assemblies.

[0063] In some embodiments, the disc spring top plate 3 is a frustum-shaped structure; a circular groove is opened at the center of its top and bottom, and the diameter of the top circular groove is smaller than the diameter of the bottom circular groove; a second annular protrusion 39 is provided at the center of the bottom circular groove; a disc spring assembly 2 is provided between the outer edge of the bottom circular groove and the floating end plate 1; the second annular protrusion 39 is engaged with the floating end plate 1; the top circular groove is used to engage the top plate nut 4.

[0064] In practical applications, during the pre-compression process of the core 10, the press pressure is transmitted to the disc spring assembly 2. After the pre-compression is completed, the disc spring force is transmitted to the shell 8 side, providing a stable force transmission plane for the disc spring assembly 2.

[0065] In some embodiments, the top plate nut 4 is a cylinder with a through hole 29 at the center; a fourth tightening mechanism 30 is provided on the inner side wall of the top of the through hole 29; a snap-fit ​​boss 40 is provided on the outer side wall of the lower part of the top plate nut 4; and a first thread pair external thread 28 is provided on the outer side wall of the top plate nut 4 above the snap-fit ​​boss 40.

[0066] In practical applications, the top plate nut 4 transmits the disc spring force from the disc spring top plate 3 to the housing 8 through the first threaded joint 31. For example... Figure 2 The top nut 4 has a first threaded pair 31 on its outer surface that mates with the inner side of the connecting through hole on the housing 8. The first threaded pair 31 can be left-handed or right-handed; in this embodiment, it is described as left-handed. The external thread 28 of the first threaded pair of the top nut 4 must have sufficient structural strength to meet the sealing force generated by the disc spring assembly 2. Figure 2 As shown, one end of the top plate nut 4 is provided with a tightening structure for connecting the tightening tool 11 to facilitate tightening with a constant torque. After pre-pressurization, the top plate nut 4 is tightened by connecting the tightening tool 11 to the fourth tightening mechanism 30 on the top plate nut 4. The through hole 29 provided in the middle of the top plate nut 4 is used for the passage of the pressure rod 12 to complete the tightening operation.

[0067] The tightening tool 11 in this embodiment includes an integral structure consisting of a hollow hexagonal prism and four tightening protrusions 36; the four tightening protrusions 36 are vertically and evenly arranged on the top surface of the hollow hexagonal prism; the side surface of the hexagonal prism forms a fifth tightening mechanism 35.

[0068] In this embodiment, the fourth tightening mechanism 30 adopts a convex-and-groove structure, which matches the convex-and-groove structure at the bottom of the tightening tool 11 for tightening the top plate nut 4. The fourth tightening mechanism 30 cooperates with the tightening boss 36 to transmit the tightening torque.

[0069] Specifically, during the core pre-compression sealing process, the compression equipment sequentially applies a vertically downward sealing force of 34kN to the core 10 via the pressure rod 12, disc spring top plate 3, disc spring assembly 2, floating end plate 1, and insulating plate 9. At this point, the disc spring assembly 2 reaches its rated compression. Meanwhile, the tightening tool 11 rotates the top plate nut 4 via the fourth tightening mechanism 30 and tightening boss 36 until the top plate nut 4 presses against the disc spring top plate 3. The sealing load applied by the pressure rod 12 to the disc spring top plate 3 is then transmitted to the housing 8 via the first threaded pair 31 that mates with the housing 8.

[0070] In some embodiments, the anti-loosening nut 5 is a disc-shaped structure with a through hole in the center; the outer side wall of the anti-loosening nut 5 is provided with a second threaded external thread 25; the upper side wall of the through hole is provided with a third tightening mechanism 27 for tightening with a constant torque and realizing the tightening and loosening of the anti-loosening nut 5; the lower side wall of the through hole is provided with a third threaded internal thread 26 for threaded connection with the lower part of the fixed shaft 6 after the fixed shaft 6 is inserted; the fixed shaft 6 is an integral structure composed of a shaft body and a shaft shoulder 23; the shaft shoulder 23 is disc-shaped, the center of the shaft shoulder 23 is located at the top of the shaft body, and a second tightening mechanism 24 for tightening the shaft body is provided at the center of its top; the shaft body is cylindrical, and the outer side wall of the shaft body is provided with a third threaded external thread 15 for connecting with the anti-loosening nut 5.

[0071] In practical use, the lock nut 5 is connected to the housing 8 via a second threaded pair 32, which can be left-handed or right-handed, but must be opposite to the first threaded pair 31. This embodiment uses the second threaded pair 32 as right-handed for technical description. A third threaded pair internal thread 26 is provided in the central through hole of the lock nut 5. This can be left-handed or right-handed, but must be opposite to the second threaded pair 32 and in the same direction as the first threaded pair 31. This embodiment uses the third threaded pair 33 as left-handed for technical description, and it is connected to the fixed shaft 6. For example... Figure 4 As shown, the third tightening mechanism 27 of the intermediate matching tool of the anti-loosening nut 5 is designed to facilitate constant torque tightening, thereby enabling the tightening and loosening of the anti-loosening nut 5.

[0072] The fixed shaft 6 and the anti-loosening nut 5 are connected by a third threaded joint 33. The shaft shoulder 23 is fixed in the groove formed by the countersunk surface of the housing 8 and the flange cover 7. The fixed shaft 6, flange cover 7, and housing 8 are fitted with an interference fit in the axial direction to restrict the degree of freedom of the fixed shaft 6 in the axial direction and around the axial direction. Figure 5 As shown, the center of the shoulder 23 of the fixed shaft 6 has a second tightening mechanism 24 for the assembly and disassembly of tightening tools to facilitate tightening with a fixed torque.

[0073] In this embodiment, both the second tightening mechanism 24 and the third tightening mechanism 27 adopt hexagonal grooves.

[0074] In some embodiments, the flange cover 7 is a disc-shaped structure with a groove at its lower part. The inner sidewall of the groove is provided with a fourth threaded internal thread 21 for connecting with the housing 8. The outer sidewall of the flange cover 7 is provided with a first tightening mechanism 22 for screwing to control the locking of the fixed shaft 6 degree of freedom.

[0075] The flange cover 7 and the housing 8 cooperate to fix the fixed shaft 6, thereby locking the degree of freedom of the fixed shaft 6. Simultaneously, the flange cover 7 and the housing 8 are connected by a fourth threaded pair 34, which can be left-handed or right-handed, but must be opposite in direction to the first threaded pair 31 and the third threaded pair 33, and in the same direction as the second threaded pair 32. This embodiment uses the fourth threaded pair 34 as right-handed for technical description. The sealing surface between the flange cover 7 and the housing 8 is sealed by a sealing ring or other means to achieve internal and external isolation of the housing 8 to meet protection requirements. Figure 7 and Figure 8 As shown. The shoulder 23 has a tightening structure at its center for easy tightening with a set torque, allowing for the use of disassembly and assembly tools.

[0076] The first tightening mechanism 22 is designed to facilitate the tightening of the flange cover 7.

[0077] Example 2:

[0078] Reference Figures 1-16 A method for packaging a fuel cell endplate encapsulation structure, comprising the following steps:

[0079] Step 1: The top plate nut 4 is connected to the housing 8 via the first threaded pair 31;

[0080] Step 2: The anti-loosening nut 5 is connected to the housing 8 and the fixed shaft 6 respectively through the second thread pair 32 and the third thread pair 33;

[0081] Step 3: The flange cover 7 is connected and fastened to the housing 8 through the fourth threaded pair 34, and the shoulder 23 of the fixed shaft 6 is fixed in the groove formed by the flange cover 7 and the housing 8.

[0082] In practical use, this embodiment achieves the locking of the degrees of freedom of each encapsulation component through the interlocking effect of the multiple threaded pairs of the encapsulation components between the core 10 and the shell 8, thereby realizing the anti-loosening effect of the threaded connection pair, effectively improving the stability and reliability of the fuel cell, and increasing the service life of the fuel cell.

[0083] The specific implementation method of this embodiment is as follows:

[0084] like Figure 8 and Figure 11 As shown, the encapsulation components are connected via a threaded joint, and during installation, they are sequentially tightened to a set torque using tightening tool 11. The anti-loosening function is implemented in the following manner:

[0085] The top plate nut 4 is connected to the housing 8 via a left-hand threaded joint, and the sealing force is transmitted from the top plate nut 4 to the housing 8 through the first threaded joint 31. The adjustable force transmission structure of the first threaded joint 31 can accommodate the tolerance fluctuation of the core 10 length, such as... Figure 9 As shown.

[0086] The top plate nut 4 transmits the sealing load through the first threaded joint 31, which is the main risk point for failure due to loosening of the threaded joint. Figure 9 As shown, the anti-loosening nut 5 is tightened to a fixed torque on the housing 8, which is connected to the top plate nut 4, via the second threaded pair 32. When the first threaded pair 31 is loosened, the top plate nut 4... Figure 8 The upward movement in the anti-loosening direction applies a torque, denoted as T1, to the anti-loosening nut 5 through the first contact surface 17 between the top nut 4 and the anti-loosening nut 5, generated by the anti-loosening action. Since the directions of the first threaded pair 31 and the second threaded pair 32 are opposite, the direction of the anti-loosening torque T1 is the same as the tightening direction of the second threaded pair 32. Therefore, the top nut 4 achieves self-locking through the anti-loosening nut 5, suppressing the anti-loosening of the first threaded pair 31.

[0087] The anti-loosening nut 5 is connected to the housing 8 and the fixed shaft 6 respectively through the second threaded pair 32 and the third threaded pair 33. Since the second threaded pair 32 and the third threaded pair 33 rotate in opposite directions and the fixed shaft 6 is fixed relative to the housing 8, the anti-loosening nut 5 achieves self-locking.

[0088] The flange cover 7 is fastened to the housing 8 via the fourth threaded joint 34, thereby limiting the axial movement of the fixed shaft 6. The flange cover 7 can also be sealed to the housing 8 via a sealing ring or other sealing structure, thus providing protection for the housing 8.

[0089] The Figure 9 As shown, the shoulder 23 of the fixed shaft 6 is fixed within the groove formed by the flange cover 7 and the housing 8. During its connection with the third threaded joint 33 of the anti-loosening nut 5, the screwing direction of the fixed shaft 6 is limited by the housing 8. When the fixed shaft 6 is screwed out, its screwing direction is limited by the flange cover 7, and a torque, denoted as T2, is applied to the flange cover 7 through the second contact surface 18 between the fixed shaft 6 and the flange cover 7. Since the third threaded joint 33 and the fourth threaded joint 34 are in opposite directions, the direction of the anti-loosening torque T2 is the tightening direction of the fourth threaded joint 34. Therefore, the fixed shaft 6 achieves self-locking and interlocking fixation.

[0090] The flange cover 7 lacks a self-locking structure, but since it does not serve as a load-bearing structure and is located on the outside of the fuel cell stack in an easily observable position, failures can be detected and suppressed in a timely manner. The failure of the fourth threaded pair 34 to loosen only involves the functional failure of the fixed shaft 6 and does not affect the self-locking structure formed by the top plate nut 4 and the anti-loosening nut 5. The stability and reliability of the encapsulation load of the fuel cell core 10 can still be guaranteed.

[0091] In summary, this invention achieves self-locking and interlocking between encapsulation components through the forward and reverse interlocking of multiple threaded pairs, especially the locking of the load-bearing structure, which effectively improves reliability and stability. At the same time, it solves the drawback of the difficulty in detecting failures in the encapsulation structure and effectively extends the service life of the fuel cell.

[0092] Where there is no conflict, those skilled in the art can combine the relevant technical features in the above examples according to the actual situation to achieve the corresponding technical effects. Specific details of the various combinations will not be elaborated here.

[0093] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0094] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features.

[0095] The above description is merely a preferred embodiment of the present invention. The present invention is not limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein. Any simple modifications, equivalent variations, and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the present invention.

Claims

1. A fuel cell endplate encapsulation structure for encapsulating a fuel cell stack core (10), characterized in that: include The shell (8) is placed outside the core (10). Multiple connecting through holes are provided on the top end face of the shell (8). The upper outer edge of the connecting through holes is higher than the top end face of the shell (8). Insulating plate (9) is placed on the top surface of core (10); Floating end plate (1), the floating end plate (1) is placed on the insulating plate (9); The telescopic encapsulation part is provided in multiple groups. The bottom end face of each group of telescopic encapsulation parts is connected to the top end face of the floating end plate (1). The top end of each group of telescopic encapsulation parts is connected to the connecting through hole at the top end of the housing (8). The number of groups of telescopic encapsulation parts provided is the same as the number of connecting through holes at the top end of the housing (8). The telescopic encapsulation part includes a disc spring assembly (2), a disc spring top plate (3), a top plate nut (4), a lock nut (5), a fixed shaft (6), and a flange cover (7); the disc spring assembly (2) is connected to the upper surface of the floating end plate (1); the top of the disc spring assembly (2) is connected to the top plate nut (4) through the disc spring top plate (3); the upper side wall of the top plate nut (4) is threadedly connected to the connecting through hole on the housing (8); the top of the top plate nut (4) is threadedly connected to the lock nut (5); the center of the lock nut (5) is vertically threadedly connected to the fixed shaft (6); the flange cover (7) is threadedly connected to the outer side wall of the connecting through hole on the housing (8) and contacts the top of the fixed shaft (6); The disc spring top plate (3) is a frustum-shaped structure; circular grooves are opened at the center of its top and bottom, and the diameter of the top circular groove is smaller than that of the bottom circular groove; a second annular protrusion (39) is provided at the center of the bottom circular groove; a disc spring assembly (2) is provided between the outer edge of the bottom circular groove and the floating end plate (1); the second annular protrusion (39) is engaged with the floating end plate (1); the top circular groove is used to engage the top plate nut (4); the top plate nut (4) is a cylinder with a through hole in the center; a fourth tightening mechanism (30) is provided on the inner side wall of the top of the through hole; a locking boss (40) is provided on the lower outer side wall of the top plate nut (4), and a first thread pair external thread (28) is provided on the outer side wall of the top plate nut (4) above the locking boss (40); the anti-loosening nut (5) is a disc-shaped structure with a through hole in the center; a second thread pair external thread (25) is provided on the outer side wall of the anti-loosening nut (5); the upper part of the through hole The side wall is provided with a third tightening mechanism (27) for tightening with a fixed torque and for tightening and loosening the anti-loosening nut (5); the lower side wall of the through hole is provided with a third threaded internal thread (26) for connecting the fixed shaft (6) to the lower thread of the fixed shaft (6) after insertion; the fixed shaft (6) is an integral structure composed of a shaft body and a shaft shoulder; the shaft shoulder (23) is disc-shaped, the center of the shaft shoulder (23) is located at the top of the shaft body, and a second tightening mechanism (24) for tightening the shaft body is provided at the center of its top; the shaft body is cylindrical, and a third threaded external thread (15) for connecting with the anti-loosening nut (5) is provided on the outer side wall of the shaft body; the flange cover (7) is a disc-shaped structure, and a groove is provided at its lower part, and a fourth threaded internal thread (21) for connecting with the housing (8) is provided on the inner side wall of the groove; a first tightening mechanism (22) for screwing to control the degree of freedom locking of the fixed shaft (6) is provided on the outer side wall of the flange cover (7). The first threaded pair (31) is left-handed or right-handed; the second threaded pair (32) is right-handed or left-handed, opposite to the first threaded pair (31); the third threaded pair (33) is left-handed or right-handed, in the same direction as the first threaded pair (31); the fourth threaded pair (34) is right-handed or left-handed, opposite to the first threaded pair (31). The failure of the fourth threaded pair (34) to loosen only involves the failure of the fixed shaft (6) function and does not affect the self-locking structure formed by the top plate nut (4) and the anti-loosening nut (5).

2. The fuel cell endplate packaging structure as described in claim 1, characterized in that: Multiple connecting through holes on the housing (8) are evenly arranged on the top surface of the housing (8); a first countersunk plate (19) and a second countersunk plate (20) are arranged from top to bottom on the inner sidewall of each connecting through hole; a fourth thread pair external thread (16) is provided on the upper outer sidewall of the connecting through hole; a second thread pair internal thread (14) is provided on the inner sidewall between the first countersunk plate (19) and the second countersunk plate (20); a first thread pair internal thread (13) is provided on the inner sidewall between the second countersunk plate (20) and the bottom end of the connecting through hole.

3. The fuel cell endplate packaging structure as described in claim 1, characterized in that: The upper surface of the floating end plate (1) is provided with a plurality of grooves (37) for connecting the telescopic encapsulation part, and the groove (37) is provided with a first annular protrusion (38) for snapping the telescopic encapsulation part; the height of the first annular protrusion (38) is greater than the thickness of the surface of the floating end plate (1).

4. A packaging method for a fuel cell endplate packaging structure, characterized in that: The fuel cell endplate packaging structure according to any one of claims 1-3 includes the following steps: Step 1: Connect the top plate nut (4) to the housing (8) via the first threaded pair (31); Step 2: Connect the lock nut (5) to the housing (8) via the second threaded pair (32), and connect it to the fixed shaft (6) via the third threaded pair (33); Step 3: Connect the flange cover (7) to the housing (8) via the fourth threaded pair (34), and fix the shoulder (23) of the fixed shaft (6) in the groove formed by the flange cover (7) and the housing (8).

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