A double-ended bolt with anti-loosening structure

Abstract

This utility model discloses a double-ended bolt with an anti-loosening structure, relating to the field of double-ended bolt technology. It includes a bolt shank body, with an expansion cavity fixedly formed on one side of the bolt shank body. A positioning groove is fixedly formed within the expansion cavity. The positioning groove within the expansion cavity of this utility model is interference-fitted with the positioning protrusion of the conical sealing plug. On the one hand, this securely fixes the shape memory alloy core inside the expansion cavity, preventing axial or circumferential displacement of the core during bolt installation or equipment vibration, ensuring that the core accurately acts on the inner wall of the expansion cavity during expansion. On the other hand, it fixes the conical sealing plug, preventing the sealing plug from falling off due to vibration and exposing the core. This dual positioning structure solves the problem of easy displacement and failure of the core anti-loosening component in traditional anti-loosening solutions, ensuring the long-term reliability of the anti-loosening system.

Description

Technical Field

[0001] This utility model relates to the field of double-ended bolt technology, specifically to a double-ended bolt with an anti-loosening structure. Background Technology

[0002] Double-ended bolts are widely used in equipment requiring high-strength connections, such as drive motors for new energy vehicles and gearboxes for wind turbines.

[0003] In existing anti-loosening solutions, spring washers are prone to elastic fatigue and preload decay due to temperature cycling; double-nut anti-loosening requires multiple calibrations of the preload torque, and there is still a risk of relative slippage of the threaded pair under vibration; chemical bonding methods are difficult to adapt to the colloid cracking caused by repeated temperature changes. More importantly, during equipment operation, due to the difference in the thermal expansion coefficients of the materials, the clearance between the bolts and the connecting parts will increase with the temperature, causing radial movement of the bolts, further aggravating the loss of preload, and in severe cases, causing abnormal noises in the equipment, wear of parts, or even safety accidents. Currently, there is no integrated solution for this complex working condition. Utility Model Content

[0004] In view of the problems of the existing anti-loosening structures of double-ended bolts, this utility model is proposed.

[0005] Therefore, the purpose of this utility model is to provide a double-ended bolt with an anti-loosening structure, which solves the problem of the risk of relative slippage of the threaded pair under vibration.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] A double-ended bolt with an anti-loosening structure includes a bolt shank body, an expansion cavity fixedly formed on one side of the bolt shank body, a positioning groove fixedly formed inside the expansion cavity, a shape memory alloy core disposed inside the expansion cavity, a conical sealing plug disposed on one side of the expansion cavity, a positioning protrusion fixedly formed on the outer side wall of one side of the conical sealing plug, a vent hole formed at the center of the conical sealing plug, a temperature compensation hole formed on the bolt shank body, and an aluminum nitride ceramic coating coated on the surface of the shape memory alloy core.

[0008] Preferably, the surface of the bolt rod body is provided with a phosphate treatment layer and a Dacromet coating layer.

[0009] Preferably, the vent hole of the conical sealing plug is filled with glass fiber filter cotton.

[0010] Preferably, the diameter of the vent hole is 2 mm.

[0011] Furthermore, the main body of the bolt rod is a cylindrical structure with an axial length of 200mm.

[0012] The technical effects and advantages provided by this utility model in the above technical solution are as follows:

[0013] 1. The present invention provides an interference fit between the positioning groove in the expansion cavity and the positioning protrusion of the conical sealing plug. On the one hand, it can firmly fix the shape memory alloy core inside the expansion cavity, preventing the core from shifting axially or circumferentially during bolt installation or equipment vibration, ensuring that the core can accurately act on the inner wall of the expansion cavity when it expands. On the other hand, it can fix the conical sealing plug, preventing the sealing plug from falling off due to vibration and exposing the core. This dual positioning structure solves the problem of easy displacement and failure of the core anti-loosening component in traditional anti-loosening solutions, ensuring the long-term reliability of the anti-loosening system.

[0014] 2. In this utility model, a vent hole is opened in the center of the conical sealing plug, and the hole is filled with glass fiber filter cotton. When the shape memory alloy core expands or contracts, the vent hole can balance the air pressure difference between the expansion chamber and the outside in real time, avoiding the problem of expansion chamber rupture due to sudden pressure increase in the chamber or sealing plug deformation due to negative pressure. At the same time, the glass fiber filter cotton can effectively block external dust, oil and other impurities from entering the expansion chamber, preventing impurities from adhering to the surface of the shape memory alloy core and affecting its phase change performance. This design not only protects the functionality of the core anti-loosening component, but also extends the service life of the core and reduces the frequency of bolt maintenance and replacement. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this utility model. For those skilled in the art, other drawings can be obtained based on these drawings.

[0016] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0017] Figure 2 This is a schematic diagram of the three-dimensional structure of the phosphating layer of this utility model;

[0018] Figure 3 For the present utility model Figure 1 Enlarged schematic diagram of part A.

[0019] Explanation of reference numerals in the attached figures:

[0020] 1. Bolt rod body; 2. Expansion cavity; 3. Positioning groove; 4. Shape memory alloy core; 5. Conical sealing plug; 6. Positioning protrusion ring; 7. Vent hole; 8. Temperature compensation hole; 9. Aluminum nitride ceramic coating; 10. Phosphating layer; 11. Dacromet coating layer; 12. Glass fiber filter cotton. Detailed Implementation

[0021] To enable those skilled in the art to better understand the technical solution of this utility model, the present utility model will be further described in detail below with reference to the accompanying drawings.

[0022] This utility model discloses a double-ended bolt with an anti-loosening structure.

[0023] This utility model provides, for example Figure 1-3A double-ended bolt with an anti-loosening structure is shown, comprising a bolt shank body 1. An expansion cavity 2 is fixedly formed on one side of the bolt shank body 1. A positioning groove 3 is fixedly formed within the expansion cavity 2. A shape memory alloy core 4 is disposed within the expansion cavity 2. A conical sealing plug 5 is provided on one side of the expansion cavity 2. A positioning protrusion ring 6 is fixedly formed on the outer wall of one side of the conical sealing plug 5. A vent hole 7 is formed in the center of the conical sealing plug 5. A temperature compensation hole 8 is formed on the bolt shank body 1. The surface of the shape memory alloy core 4 is coated with an aluminum nitride ceramic coating 9. When the bolt is used in equipment such as new energy vehicle drive motors and wind turbine gearboxes, the heat generated during equipment operation raises the ambient temperature. When the temperature reaches the shape memory alloy core... At the phase transformation temperature of body 4, the core transforms from a low-temperature martensitic phase to a high-temperature austenitic phase, accompanied by volume expansion. The aluminum nitride ceramic coating 9 on the core surface can quickly and uniformly transfer heat, ensuring the core's overall synchronous phase transformation expansion and avoiding expansion deviation caused by uneven local heating. This allows the core's expansion force to act evenly on the inner wall of the expansion cavity 2. The expanding core pushes the inner wall of the expansion cavity 2 to expand radially, thereby precisely filling the gap between the bolt rod body 1 and the connector mounting hole caused by the difference in thermal expansion coefficients. This eliminates the radial movement space of the bolt. At the same time, filling the gap makes the bolt and connector fit more tightly, avoiding the loss of preload caused by the gap, ensuring stable operation of the equipment. During the repeated temperature changes during equipment operation, the bolt rod... The main body 1 will expand and contract due to temperature fluctuations. At this time, the temperature compensation hole 8, which runs axially through the bolt rod, can absorb part of the thermal stress generated by the expansion and contraction of the main body 1 through its own structural deformation, avoiding cracks, bending and other deformation problems caused by thermal stress concentration in the bolt rod, thus ensuring the structural integrity of the bolt. The spiral heat dissipation groove on the inner wall of the temperature compensation hole 8 can increase the heat dissipation area, assist the main body 1 of the bolt rod in rapid heat dissipation, reduce the damage to the bolt material caused by sudden temperature rises and falls, and further improve the stability of the bolt under temperature change conditions. During the expansion or contraction of the shape memory alloy core 4, the vent 7 in the center of the conical sealing plug 5 can balance the air pressure difference between the expansion chamber 2 and the outside in real time, avoiding the expansion chamber 2 from rupturing due to a sudden increase in internal pressure, or negative pressure. The pressure causes the sealing plug to tighten and deform. Simultaneously, the glass fiber filter cotton 12 inside the vent 7 effectively blocks external dust, oil, and other impurities from entering the expansion chamber 2, preventing impurities from adhering to the core surface and affecting its phase change performance. This ensures the core's long-term stable anti-loosening function. The phosphated layer 10 and Dacromet coating 11 on the surface of the bolt body 1 form a dual protection system: the phosphated layer forms a dense protective film on the bolt surface, enhancing the adhesion between the substrate and the Dacromet coating; the Dacromet coating, with its excellent salt spray resistance, resists the erosion of rainwater, salt, dust, and other corrosive media, preventing problems such as reduced structural strength and connection failure due to corrosion, extending the bolt's service life, and adapting to the harsh working conditions of new energy vehicles, wind power equipment, etc.

[0024] For greater durability, such as Figure 2As shown, the surface of the bolt rod body 1 is provided with a phosphate treatment layer 10 and a Dacromet coating layer 11.

[0025] In order to block the vent 7, such as Figure 3 As shown, the vent hole 7 of the conical sealing plug 5 is filled with glass fiber filter cotton 12.

[0026] For better use, such as Figure 3 As shown, the diameter of the vent 7 is 2mm.

[0027] Finally, for ease of use, such as Figure 1 As shown, the main body 1 of the bolt rod is a cylindrical structure with an axial length of 200mm.

[0028] The foregoing description only illustrates certain exemplary embodiments of the present invention. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A double-ended bolt with an anti-loosening structure, comprising a bolt shank body (1), characterized in that, An expansion cavity (2) is fixedly opened on one side of the bolt rod body (1). A positioning groove (3) is fixedly opened in the expansion cavity (2). A shape memory alloy core (4) is provided in the expansion cavity (2). A conical sealing plug (5) is provided on one side of the expansion cavity (2). A positioning protrusion ring (6) is fixedly provided on the outer side wall of one side of the conical sealing plug (5). A vent hole (7) is opened in the center of the conical sealing plug (5). A temperature compensation hole (8) is opened on the bolt rod body (1). The surface of the shape memory alloy core (4) is coated with an aluminum nitride ceramic coating (9).

2. A double-ended bolt with an anti-loosening structure according to claim 1, characterized in that, The surface of the bolt rod body (1) is provided with a phosphate treatment layer (10) and a Dacromet coating layer (11).

3. A double-ended bolt with an anti-loosening structure according to claim 1, characterized in that, The vent (7) of the conical sealing plug (5) is filled with glass fiber filter cotton (12).

4. A double-ended bolt with an anti-loosening structure according to claim 1, characterized in that, The diameter of the vent (7) is 2 mm.

5. A double-ended bolt with an anti-loosening structure according to claim 1, characterized in that, The main body (1) of the bolt rod is a cylindrical structure with an axial length of 200mm.

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