Screw anti-loosening structure for fuel cell and stack clamping device

Abstract

The application provides a screw anti-loosening structure for a fuel cell and a stack clamping device, which comprises a rotation-stopping block and a rotation-stopping spring, the rotation-stopping block is provided with a through hole, the rotation-stopping spring is arranged in the through hole; a threaded hole is arranged on a mounting body, the rotation-stopping block is threadedly connected with the threaded hole, one end of a screw rod is threadedly connected with the threaded hole through the through hole and the rotation-stopping spring; the rotation-stopping spring is a spiral structure, the screw rod is threadedly connected with the rotation-stopping spring; a limiting groove is arranged on the through hole, limiting columns are arranged at two ends of the rotation-stopping spring, and the limiting columns are located in the limiting groove; a nut on the screw rod abuts against the rotation-stopping block. The application solves the problem of loosening of a double-end screw rod during vibration, impact and large temperature change of a stack, reduces the dismounting difficulty of the anti-loosening structure, and improves the stability of the stack operation.

Description

Technical Field

[0001] This invention relates to the field of fuel cell technology, specifically to a screw anti-loosening structure and a fuel cell stack clamping device for fuel cells. Background Technology

[0002] Fuel cells are devices that convert the chemical energy from the reaction of hydrogen and oxygen into electrical energy through an electrochemical reaction. To meet the power demands of everyday vehicles, multiple individual cells need to be stacked in series to achieve high power output. After stacking, the cells must be clamped and secured to ensure efficient reaction. Traditionally, double-ended screws are used for clamping, relying on the friction between the threads to prevent loosening, suitable for static loads or conditions with minimal temperature changes. However, as fuel cell stack applications expand, the resulting vibration, impact, and temperature fluctuation environments become increasingly complex and demanding. Over time, this can affect the clamping force of the double-ended screws, causing them to loosen, severely impacting stack performance and even leading to stack failure. Furthermore, the clamping force between individual cells changes due to thermal expansion and contraction, affecting the contact resistance between cells and impacting stack performance. Therefore, implementing anti-loosening designs for the double-ended screw structure to ensure stable stack operation is crucial for improving the reliability of the fuel cell stack structure.

[0003] The principle of anti-loosening is to prevent relative rotation of the screw pair under load. The fundamental methods can be divided into friction anti-loosening, mechanical anti-loosening, and permanent anti-loosening. Friction anti-loosening is relatively simple, typically using elastic washers, double nuts, self-locking nuts, and nylon insert lock nuts to achieve the locking effect, but it is only suitable for simple working conditions. Mechanical anti-loosening is more reliable, using stoppers to directly restrict the relative rotation of the threaded pair. Permanent anti-loosening involves damage to the threads and is difficult to disassemble, and is only suitable for permanent fixation.

[0004] Patent document CN116104857A discloses a self-locking anti-loosening connection assembly, comprising a fastening nut, a locking nut, and an elastic interlocking ring. One end face of the elastic interlocking ring has interlocking ring check teeth that engage with the nut check teeth on the locking nut. The end face of the fastening nut has a clamping tube. Through the tapered jaw on the locking nut, and the engagement between the thread inside the clamping tube and the screw, the nut achieves self-locking. However, this structure is difficult to manufacture, and when the screw needs to be screwed into the end plate, the nut cannot be installed or removed.

[0005] Therefore, how to prevent the double-ended screw from loosening, ensure the anti-loosening structure is easy to assemble and disassemble, effectively clamp and fix the fuel cell stack, and improve the reliability of the fuel cell stack has become a key problem that needs to be solved by those skilled in the art. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the purpose of this invention is to provide a screw anti-loosening structure and a stack clamping device for fuel cells.

[0007] According to the present invention, a screw anti-loosening structure for a fuel cell includes an anti-rotation block and an anti-rotation spring, wherein the anti-rotation block is provided with a through hole and the anti-rotation spring is disposed in the through hole;

[0008] The mounting body is provided with a threaded hole, the anti-rotation block is threadedly connected to the threaded hole, and one end of the screw passes through the through hole and the anti-rotation spring is threadedly connected to the threaded hole;

[0009] The anti-rotation spring has a helical structure, and the screw is threadedly connected to the anti-rotation spring; a limiting groove is provided on the through hole, and limiting posts are provided at both ends of the anti-rotation spring, with the limiting posts located in the limiting groove;

[0010] The nut on the screw abuts against the anti-rotation block.

[0011] Preferably, the through hole is a stepped hole;

[0012] The stepped hole includes a through hole and a placement hole, the diameter of which is larger than that of the through hole, and the anti-rotation spring is disposed in the placement hole;

[0013] One end of the screw passes through the through hole, and the anti-rotation spring inside the placement hole is threadedly connected to the threaded hole.

[0014] Preferably, the anti-rotation block includes a cylindrical portion and a hexagonal portion connected together;

[0015] The cylindrical portion is provided with the placement hole, and the hexagonal portion is provided with the through hole;

[0016] The outer wall of the cylindrical part is provided with a threaded structure, and the cylindrical part is threadedly connected to the threaded hole.

[0017] Preferably, the threaded hole is a stepped threaded hole;

[0018] The stepped threaded hole includes an internal threaded hole and an external threaded hole. The diameter of the external threaded hole is larger than that of the internal threaded hole. The cylindrical portion is threadedly connected to the external threaded hole, and the screw is threadedly connected to the internal threaded hole.

[0019] Preferably, a steel sheet is provided inside the anti-rotation spring, and the steel sheet passes through the anti-rotation spring.

[0020] The present invention also provides a fuel cell stack clamping device, including the above-mentioned fuel cell screw anti-loosening structure.

[0021] Preferably, it further includes a second clamping plate and a nut sleeve; the mounting body is the first clamping plate, and the screw is a double-ended screw;

[0022] The fuel cell stack is clamped between the first clamping plate and the second clamping plate; the second clamping plate is provided with an optical aperture.

[0023] One end of the double-ended screw passes through the light hole, the anti-rotation block, and the anti-rotation spring and is threadedly connected to the threaded hole;

[0024] The nut sleeve is disposed at the other end of the double-ended screw, and the nut sleeve is located inside the optical hole.

[0025] Preferably, it further includes an end plate, which is sandwiched between the second clamping plate and the fuel cell stack.

[0026] Preferably, it further includes an elastomer sandwiched between the end plate and the second clamping plate.

[0027] Preferably, the end plate is provided with an end plate groove, and the second clamping plate is provided with a clamping plate groove;

[0028] The end plate groove and the clamping plate groove together form a mounting groove, and the elastomer is located in the mounting groove.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] 1. The clamping device of the present invention can effectively clamp the fuel cell stack when it is subjected to vibration, impact and large temperature changes, solves the problem of the screw loosening and sliding out as the nut rotates with the screw, and improves the stability of the fuel cell stack operation;

[0031] 2. This invention solves the problem of uneven stress on a single cell when subjected to large temperature changes, ensuring the contact resistance between single cells and effectively improving the reaction efficiency.

[0032] 3. The clamping device of the present invention has a simple structure, is easy to disassemble and assemble, saves maintenance costs, and provides a new approach to locking and fixing double-ended screws in blind holes;

[0033] 4. This invention solves the problem of double-headed screw loosening when the fuel cell stack is subjected to vibration, impact and large temperature changes, reduces the difficulty of disassembling and assembling the anti-loosening structure and improves the stability of fuel cell stack operation. Attached Figure Description

[0034] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0035] Figure 1This is a schematic diagram of the assembly of a double-headed screw clamping device.

[0036] Figure 2 A cross-sectional schematic diagram of a double-headed screw clamping device;

[0037] Figure 3 for Figure 2 A magnified view of a portion of point A in the middle;

[0038] Figure 4 This is a schematic diagram of the anti-rotation spring and anti-rotation block.

[0039] The diagram shows:

[0040] Mounting body 1, Nuts 5

[0041] Threaded hole 101, screw 6

[0042] fuel cell stack 2 end plate 7

[0043] Anti-rotation spring 3, end plate groove 701

[0044] Limiting post 301 Second clamping plate 8

[0045] 302 steel sheet, 801 aperture

[0046] Anti-rotation block 4, clamping plate groove 802

[0047] Limiting groove 401 nut sleeve 9

[0048] Cylindrical part 402 Elastomer 10

[0049] Hexagonal part 403 Detailed Implementation

[0050] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0051] Example 1:

[0052] like Figures 1-4As shown, this embodiment provides a screw anti-loosening structure for a fuel cell, including an anti-rotation block 4 and an anti-rotation spring 3. The anti-rotation block 4 is provided with a through hole, and the anti-rotation spring 3 is disposed in the through hole. The mounting body 1 is provided with a threaded hole 101, and the anti-rotation block 4 is threadedly connected to the threaded hole 101. One end of the screw 6 passes through the through hole and the anti-rotation spring 3 and is threadedly connected to the threaded hole 101. The anti-rotation spring 3 has a helical structure, and the screw 6 is threadedly connected to the anti-rotation spring 3. A limiting groove 401 is provided on the through hole, and limiting posts 301 are provided at both ends of the anti-rotation spring 3. The limiting posts 301 are located in the limiting groove 401, and the nut 5 on the screw 6 abuts against the anti-rotation block 4.

[0053] A steel plate 302 is installed inside the anti-rotation spring 3, and the steel plate 302 passes through the anti-rotation spring 3.

[0054] The through hole is a stepped hole, which includes a through hole and a placement hole. The diameter of the placement hole is larger than that of the through hole. The anti-rotation spring 3 is disposed in the placement hole. One end of the screw 6 passes through the through hole and the anti-rotation spring 3 in the placement hole is threadedly connected to the threaded hole 101. The anti-rotation block 4 includes a cylindrical part 402 and a hexagonal part 403 connected to each other. The cylindrical part 402 is provided with a placement hole, and the hexagonal part 403 is provided with a through hole. The outer wall of the cylindrical part 402 is provided with a threaded structure, and the cylindrical part 402 is threadedly connected to the threaded hole 101.

[0055] The anti-rotation spring 3 is placed in the placement hole, and there is a gap between the anti-rotation spring 3 and the peripheral wall of the placement hole. The anti-rotation spring 3 is completely attached to the screw. With this setting, when the anti-rotation block 4 rotates counterclockwise or is subjected to a counterclockwise rotational torque, the limiting post 301 will drive the anti-rotation spring 3 to rotate counterclockwise or subject the anti-rotation spring 3 to a counterclockwise rotational torque, thereby causing the anti-rotation spring 3 to grip the screw.

[0056] The threaded hole 101 is a stepped threaded hole, which includes an internal threaded hole and an external threaded hole. The diameter of the external threaded hole is larger than that of the internal threaded hole. The cylindrical part 402 is threadedly connected to the external threaded hole, and the screw 6 is threadedly connected to the internal threaded hole.

[0057] This embodiment also provides a fuel cell stack clamping device, including the above-mentioned fuel cell screw anti-loosening structure.

[0058] The fuel cell stack clamping device of this embodiment also includes a second clamping plate 8 and a nut sleeve 9. The mounting body 1 is the first clamping plate, the screw 6 is a double-ended screw, and the fuel cell stack 2 is clamped between the first clamping plate and the second clamping plate 8. The second clamping plate 8 is provided with a light hole 801. One end of the double-ended screw passes through the light hole 801, the anti-rotation block 4, the anti-rotation spring 3, and is threadedly connected to the threaded hole 101. The nut sleeve 9 is provided at the other end of the double-ended screw and is located inside the light hole 801.

[0059] The fuel cell stack clamping device of this embodiment further includes an end plate 7, which is clamped between the second clamping plate 8 and the fuel cell stack 2. The fuel cell stack clamping device of this embodiment also includes an elastic body 10, which is clamped between the end plate 7 and the second clamping plate 8. The end plate 7 has an end plate groove 701, and the second clamping plate 8 has a clamping plate groove 802. The end plate groove 701 and the clamping plate groove 802 together form a mounting groove, and the elastic body 10 is located within the mounting groove. In this embodiment, two elastic bodies 10 are provided, which can be elastic pads.

[0060] Nut 5, anti-rotation block 4, anti-rotation spring 3, and nut sleeve 9 are all made of stainless steel 304.

[0061] In this embodiment, there are six screws 6, distributed on both sides of the fuel cell stack, three on each side, with the three screws evenly spaced. Each screw 6 is equipped with the aforementioned components and is arranged as described above.

[0062] Working principle :

[0063] This embodiment provides a fuel cell stack clamping device, comprising a clamping plate with stepped screw holes, a double-ended screw, an anti-rotation structure, and a nut. The anti-rotation structure includes an anti-rotation block 4 with external threads and internal stepped holes, and a push spring 3 that prevents the steel plate from being penetrated. When the double-ended screw is subjected to a rotational torque, it drives the nut 5 and the anti-rotation block 4 to rotate counterclockwise. At this time, friction is generated between the double-ended screw and the first clamping plate, between the nut 5 and the anti-rotation block 4, and between the outer thread of the anti-rotation block 4 and the first clamping plate. Furthermore, the anti-rotation block 4 drives the internal anti-rotation spring 3 to rotate counterclockwise, causing the anti-rotation spring 3 to generate a certain tension, gradually clamping the double-ended screw. Multiple resistances prevent the double-ended screw from unscrewing. In this process, by decomposing the rotational torque, the phenomenon of the nut rotating with the double-ended screw is reduced or eliminated, solving the problem of the double-ended screw loosening under vibration, impact, and large temperature changes, reducing the difficulty of disassembling and assembling the anti-loosening structure, and improving the stability of the fuel cell stack operation.

[0064] Example 2:

[0065] Those skilled in the art can understand this embodiment as a more specific description of Embodiment 1.

[0066] This embodiment provides a double-ended screw anti-loosening clamping device, which can effectively achieve the clamping and fixing of the fuel cell stack. It is designed from the perspective of mechanical anti-loosening, providing a new approach to the blind hole anti-loosening fixing of double-ended screws for fuel cells.

[0067] Specific method: After the fuel cell stack is clamped, a double-ended screw assembly with an anti-loosening structure is installed on the threaded plate and the perforated plate. When the double-ended screw is subjected to external force and rotates outward, the anti-rotation spring is subjected to rotational torque and gradually clamps the screw, preventing the screw from loosening further.

[0068] The threaded plate and the perforated plate are made of aluminum alloy. The threaded plate has stepped threaded holes. The smaller internal threaded holes match the double-ended screw, while the larger external threaded holes match the anti-rotation block.

[0069] The double-ended screw assembly includes a nut, an anti-rotation block, an anti-rotation spring, and a nut sleeve, and is made of 304 stainless steel to enhance its corrosion resistance.

[0070] In the anti-rotation spring structure, the steel sheet runs through the spiral structure, like a ring-shaped track. This structure can greatly enhance the anti-torsion effect of the anti-rotation spring.

[0071] The anti-rotation block is divided into two sections on its outer side: a circular outer surface and a hexagonal outer surface. The circular outer surface is threaded and screwed into a threaded plate, while the hexagonal outer surface is for tightening the anti-rotation block with a wrench. To accommodate the anti-rotation spring structure, a stepped hole is formed inside the anti-rotation block. One end of the circular outer surface has a larger through hole, and two anti-rotation block grooves are formed at the edge of the through hole to accommodate the two ends of the anti-rotation spring. This prevents the anti-rotation spring from rotating with the anti-rotation block when subjected to rotational torque, thus ensuring the reliability of the anti-loosening mechanism.

[0072] This embodiment also provides a method for fastening the fuel cell stack, the specific operation method of which is as follows:

[0073] After the fuel cell stack is press-fitted, remove the double-ended screw, screw a nut sleeve onto one end, pass the screw through the aperture of the perforated plate, and screw a nut onto the other end. Embed the anti-rotation spring within the anti-rotation block, ensuring both ends of the spring are positioned within the grooves of the block. Then screw the anti-rotation block into the threaded plate and tighten it with a torque wrench. Next, slowly screw the double-ended screw and nut assembly into the screw holes of the threaded plate until the nut is flush with the metal parts. Repeat the same operation for the remaining screws to complete the fuel cell stack tightening process. Finally, tighten the nuts to the specified torque using a torque wrench.

[0074] When it is necessary to disassemble the screw, first loosen the nut, then slowly loosen the anti-reverse block with a wrench, and finally slowly loosen the screw to disassemble it.

[0075] The clamping device of the present invention can effectively clamp the fuel cell stack when it is subjected to vibration, impact, or large temperature changes, solving the problem of the screw loosening and sliding out as the nut rotates with the screw, and improving the stability of the fuel cell stack operation.

[0076] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0077] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A screw anti-loosening structure for a fuel cell, characterized in that, It includes an anti-rotation block (4) and an anti-rotation spring (3), wherein the anti-rotation block (4) is provided with a through hole and the anti-rotation spring (3) is disposed in the through hole; The mounting body (1) is provided with a threaded hole (101), the anti-rotation block (4) is threadedly connected to the threaded hole (101), and one end of the screw (6) passes through the through hole and the anti-rotation spring (3) is threadedly connected to the threaded hole (101). The anti-rotation spring (3) has a helical structure, and the screw (6) is threadedly connected to the anti-rotation spring (3); a limiting groove (401) is provided on the through hole, and limiting posts (301) are provided at both ends of the anti-rotation spring (3), and the limiting posts (301) are located in the limiting groove (401); The nut (5) on the screw (6) abuts against the anti-rotation block (4); The through hole is a stepped hole; The stepped hole includes a through hole and a placement hole, the diameter of the placement hole is larger than that of the through hole, and the anti-rotation spring (3) is disposed in the placement hole; One end of the screw (6) passes through the through hole, and the anti-rotation spring (3) in the placement hole is threadedly connected to the threaded hole (101); A steel sheet (302) is provided inside the anti-rotation spring (3), and the steel sheet (302) passes through the anti-rotation spring (3); There is a gap between the anti-rotation spring (3) and the peripheral wall of the placement hole.

2. The anti-loosening structure for a fuel cell screw according to claim 1, characterized in that, The anti-rotation block (4) includes a cylindrical part (402) and a hexagonal part (403) connected to each other. The cylindrical portion (402) is provided with the placement hole, and the hexagonal portion (403) is provided with the through hole; The outer wall of the cylindrical part (402) is provided with a threaded structure, and the cylindrical part (402) is threadedly connected to the threaded hole (101).

3. The anti-loosening structure for a fuel cell screw according to claim 2, characterized in that, The threaded hole (101) is a stepped threaded hole; The stepped threaded hole includes an internal threaded hole and an external threaded hole. The diameter of the external threaded hole is larger than that of the internal threaded hole. The cylindrical part (402) is threadedly connected to the external threaded hole, and the screw (6) is threadedly connected to the internal threaded hole.

4. A fuel cell stack clamping device, characterized in that, Includes the screw anti-loosening structure for fuel cells as described in any one of claims 1 to 3.

5. The fuel cell stack clamping device according to claim 4, characterized in that, It also includes a second clamping plate (8) and a nut sleeve (9); the mounting body (1) is the first clamping plate, and the screw (6) is a double-ended screw; The fuel cell stack (2) is sandwiched between the first clamping plate and the second clamping plate (8); the second clamping plate (8) is provided with a light hole (801); One end of the double-ended screw passes through the light hole (801), the anti-rotation block (4), the anti-rotation spring (3), and is threadedly connected to the threaded hole (101); The nut sleeve (9) is disposed at the other end of the double-ended screw, and the nut sleeve (9) is located inside the light hole (801).

6. The fuel cell stack clamping device according to claim 5, characterized in that, It also includes an end plate (7), which is sandwiched between the second clamping plate (8) and the fuel cell stack (2).

7. The fuel cell stack clamping device according to claim 6, characterized in that, It also includes an elastomer (10) sandwiched between the end plate (7) and the second clamping plate (8).

8. The fuel cell stack clamping device according to claim 7, characterized in that, The end plate (7) is provided with an end plate groove (701), and the second clamping plate (8) is provided with a clamping plate groove (802). The end plate groove (701) and the clamping plate groove (802) together form an installation groove, and the elastic body (10) is located in the installation groove.

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