High-strength anti-vibration anti-loosening fastener

Abstract

The utility model relates to the technical field of fasteners, in particular to a high-strength anti-vibration anti-loose fastener. The high-strength anti-vibration anti-loose fastener comprises a connecting body and a set screw. The connecting body comprises a pre-tightening section, a transition section and a connecting section which are sequentially connected. And a plurality of threaded through holes are formed in the pre-tightening section. A pressing end face is arranged on the side, close to the transition section, of the pre-tightening section. And a tightening column is arranged on the pre-tightening section. And the tightening column is positioned among the plurality of threaded through holes. And an external thread is arranged on the side wall of the connecting section. The set screw is screwed in the threaded through hole in the direction, pointing from the pre-tightening section to the connecting section, of the connecting body. A cylindrical section used for extending out of the threaded through hole is arranged at the end of the set screw. According to the high-strength anti-vibration anti-loosening fastener, the strength of a bolt connecting structure is improved, the difficulty of applying pre-tightening force is reduced, and the anti-vibration performance and the anti-loosening effect are improved.

Description

Technical Field

[0001] This utility model relates to the field of fastener technology, specifically to a high-strength, vibration-resistant, and anti-loosening fastener. Background Technology

[0002] Fastener connections in heavy machinery typically use bolts. To ensure the reliability of bolted connections, preload is often applied to the bolts during assembly to meet preload requirements. For example, in the assembly process of the "magnetic cage" component in a nuclear power plant reactor, the preload of bolted connections is required to reach hundreds of tons.

[0003] Currently, super bolts are commonly used for connection in the aforementioned assembly process. Existing super bolt structures include a nut and a screw. The nut has multiple threaded through holes on its end face, and the screw passes through the connecting component. The nut is screwed onto the screw from one side of the connecting component, forming a basic bolted connection structure. A set screw, matching the threaded through holes, is screwed into the nut from its end face. The end face of the set screw applies axial pressure to the end face of the connecting component through its threads, thereby locking the screw.

[0004] However, under conditions of high vibration, variable load, and temperature stress, even minor deformation of the threads in these super bolts can lead to loosening of the bolted connection. For example, temperature stress causes thermal expansion and contraction of the metal, affecting the tight connection between the bolt and nut. At extreme temperatures, thermal cycling accelerates the loosening of the connection. Furthermore, prolonged use and repeated tightening and loosening operations cause thread wear and fatigue, reducing the thread's engagement force and anti-loosening performance. Summary of the Invention

[0005] The purpose of this invention is to provide a fastener structure for the assembly of fasteners in heavy machinery, thereby improving the strength of bolted connections, reducing the difficulty of applying pre-tightening force, and enhancing vibration resistance and anti-loosening effect.

[0006] To achieve the above objectives, the present invention adopts the following solution:

[0007] A high-strength vibration-resistant and anti-loosening fastener includes a connecting body and a set screw;

[0008] The connecting body includes a pre-tightening section, a transition section, and a connecting section connected in sequence. The pre-tightening section is provided with multiple threaded through holes. The side of the pre-tightening section near the transition section is provided with a pressing end face. The pre-tightening section is provided with a tightening post, which is located between the multiple threaded through holes. The side wall of the connecting section is provided with external threads.

[0009] The set screw is screwed into the threaded through hole along the direction from the pre-tightening section to the connecting section on the connecting body, and the end of the set screw is provided with a cylindrical section for extending out of the threaded through hole.

[0010] The connecting body is inserted into the mounting hole of the structure to be assembled. The connecting section of the connecting body is used to cooperate with the nut or directly cooperate with the mounting thread hole. The tightening column is used to apply torque to the connecting body by the external installation tool. After the connecting body is installed on the structure to be assembled, the set screw is screwed into the threaded through hole. By tightening multiple set screws, the cylindrical section of the set screw is used to apply axial clamping force to the structure to be assembled, thereby applying preload to the connecting body.

[0011] Preferably, the high-strength vibration-resistant and anti-loosening fastener proposed in this utility model also includes a washer, which is sleeved on the transition section. With this arrangement, during use, the washer is located between the clamping end face and the structure to be assembled, protecting the contact end face of the structure to be assembled. This facilitates the even distribution of the axial load applied by the set screw to the structure to be assembled, avoiding stress concentration.

[0012] Preferably, a neck groove is provided between the pre-tightening section and the transition section. The neck groove extends from the clamping end face towards the side wall of the transition section. The neck groove includes a first arcuate groove and a second arcuate groove. The first arcuate groove is located on the clamping end face, and the second arcuate groove is located on the side wall of the transition section, with a smooth transition between the first and second arcuate grooves. This arrangement allows the neck groove to provide axial auxiliary positioning for the assembly of the washer, and also provides space for the deformation of the washer using the first and second arcuate grooves, which helps the washer to more evenly transmit the axial clamping force applied by the set screw to the structure to be assembled.

[0013] Preferably, the tightening column is coaxially arranged with the connecting body.

[0014] Preferably, the threaded through holes are arranged in a circular pattern along the axis of the connecting body.

[0015] Preferably, the tightening column is a hexagonal segment.

[0016] Preferably, a groove is provided between the transition section and the connecting section. With this design, the groove plays an important role in the external thread machining of the connecting section, such as chip removal, tool cooling, reduction of cutting force, improvement of machining accuracy and extension of tool life, which further improves the machining efficiency and quality of external threads, thereby improving the strength of the bolt connection structure. At the same time, the groove acts as a transition between the transition section and the connecting section, avoiding stress concentration.

[0017] Preferably, the radius of the first arc groove is 5mm-7.5mm, and the radius of the second arc groove is 3mm-5mm.

[0018] Compared with existing technologies, the high-strength vibration-resistant and anti-loosening fastener provided by this utility model has the following substantial features and advancements: This high-strength vibration-resistant and anti-loosening fastener, through the cooperation of the tightening post and threaded through holes set on the pre-tightening section, can effectively disperse and resist the impact force caused by vibration. The set screw, by engaging within multiple threaded through holes, reduces the difficulty of applying pre-tightening force, further enhancing the vibration resistance of the fastener, avoiding loosening problems caused by vibration, and improving the strength of the bolt connection structure. Compared with the structure of super bolts in existing technologies, the pre-tightening section on the connecting body optimizes the nut structure in super bolts. During the assembly of heavy machinery, it avoids the wear and tear caused by repeated disassembly and assembly of the nut structure. A bolt connection structure can be formed using only ordinary nuts in conjunction with the connecting body, further reducing the usage cost of the nut structure. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the assembly structure of a high-strength vibration-resistant and anti-loosening fastener according to an embodiment of this utility model.

[0020] Figure 2 yes Figure 1 A partial cross-sectional view of the main body in the middle.

[0021] Figure 3 This is a schematic diagram of the end face structure of the connecting body in an embodiment of this utility model.

[0022] Figure 4 yes Figure 2 A magnified schematic diagram of the structure at point A in the middle.

[0023] Figure 5 This is a schematic diagram of the set screw in an embodiment of this utility model.

[0024] Reference numerals: 1. Connecting body; 2. Set screw; 3. Washer; 4. Groove; 11. Pre-tightening section; 12. Transition section; 13. Connecting section; 14. Pressing end face; 15. Tightening column; 16. Threaded through hole; 17. Neck groove; 21. Cylindrical section; 171. First arc groove; 172. Second arc groove. Detailed Implementation

[0025] The specific embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0026] like Figures 1-5 As shown in the present invention, a high-strength anti-vibration and anti-loosening fastener is proposed in this embodiment, which aims to improve the strength of bolted connection structures, reduce the difficulty of applying pre-tightening force, and improve vibration resistance and anti-loosening effect.

[0027] The high-strength vibration-resistant and anti-loosening fastener proposed in this embodiment of the invention effectively disperses and resists the impact force caused by vibration through the cooperation of the tightening post 15 and the threaded through hole 16 set on the pre-tightening section 11. The set screw 2, by engaging in multiple threaded through holes 16, reduces the difficulty of applying pre-tightening force, further enhances the vibration resistance of the fastener, avoids loosening caused by vibration, and improves the strength of the bolt connection structure. This high-strength vibration-resistant and anti-loosening fastener is equivalent to integrating the nut structure of the super bolt in the prior art onto the connecting body 1. The pre-tightening section 11 on the connecting body 1 optimizes the nut structure in the super bolt. During the assembly of heavy machinery, it avoids the wear and tear caused by repeated disassembly and assembly of the nut structure. A bolt connection structure can be formed by using only an ordinary nut with the connecting body 1, further reducing the usage cost of the nut structure.

[0028] like Figure 1 Combination Figure 2 As shown, a high-strength vibration-resistant and anti-loosening fastener includes a connecting body 1 and a set screw 2. The connecting body 1 includes a pre-tightening section 11, a transition section 12, and a connecting section 13 connected in sequence. The pre-tightening section 11 is provided with multiple threaded through holes 16. A clamping end face 14 is provided on the side of the pre-tightening section 11 near the transition section 12. A tightening post 15 is provided on the pre-tightening section 11. The tightening post 15 is located between the multiple threaded through holes 16. External threads are provided on the side wall of the connecting section 13.

[0029] like Figure 1 As shown, the set screw 2 is screwed into the threaded through hole 16 along the direction from the pre-tightening section 11 to the connecting section 13 on the connecting body 1. Figure 5 As shown, the end of the set screw 2 is provided with a cylindrical section 21 for extending out of the threaded through hole 16.

[0030] The connecting body 1 passes through the mounting hole of the structure to be assembled. The connecting section 13 of the connecting body 1 is used to mate with a nut or directly mate with a threaded mounting hole. The tightening post 15 is used to apply torque to the connecting body 1 for external installation tools. After the connecting body 1 is installed on the structure to be assembled, the set screws 2 are screwed into the threaded through hole 16. By tightening multiple set screws 2, the cylindrical section 21 of the set screws 2 applies axial clamping force to the structure to be assembled, thereby applying preload force to the connecting body 1.

[0031] For example, the tightening post 15 is coaxially arranged with the connecting body 1. The threaded through holes 16 are arranged in a circle along the axis of the connecting body 1. Figure 3As shown, 10 threaded through holes 16 are arranged in a circle along the axis of the connecting body 1. The number of threaded through holes 16 is selected appropriately based on the structural dimensions of the preload section 11 and the connecting load borne by the connecting body 1. Preferably, there are 6-12 threaded through holes 16, and the number of set screws 2 corresponds one-to-one with the number of threaded through holes 16.

[0032] The processing of the connection body 1 of the high-strength vibration-resistant and anti-loosening fastener proposed in this embodiment of the utility model includes the following processing steps:

[0033] Step 1. Material chemical analysis (third-party testing agency);

[0034] Step 2. Cutting: ∅65*245;

[0035] Step 3. Normalizing: Refer to the heat treatment process (flaw detection) for 42CrMo material;

[0036] Step 4. Rough machining: Leave a 0.5mm allowance on one side of the outer shape;

[0037] Step 5. Vacuum quenching: Refer to the heat treatment process for 42CrMo material, hardness: HRC39~44;

[0038] Process 6. Finishing: ① Turn the shape to meet the drawing requirements, ② Position the tooling, CNC machine a 6*18 hexagonal hole, and machine a 10×M10-6H threaded hole (boring the threaded bottom hole and using a thread milling cutter to machine the thread), and record the inspection results during the machining process;

[0039] Step 7. Inspection;

[0040] Step 8. Flaw detection: Ultrasonic flaw detection, magnetic particle flaw detection;

[0041] Step 9. Performance testing of assembled components: ① Preload test, ② Vibration test, ③ Sample tensile test (third-party testing agency);

[0042] Step 10. Packaging and warehousing.

[0043] To further improve the structural strength of the connecting body 1, the connecting body 1 is made of 718 stainless steel and includes 6 vacuum heat treatment processes.

[0044] like Figure 3 As shown, the tightening post 15 is a hexagonal segment. This design allows the connecting body 1 to be compatible with existing conventional tightening wrenches, provides better anti-rotation performance for the connecting body 1, and helps maintain the stability of the connection, especially under high vibration or dynamic load conditions.

[0045] like Figure 1As shown, the high-strength vibration-resistant and anti-loosening fastener proposed in this utility model includes a connecting body 1, a set screw 2, and a washer 3. The washer 3 is fitted onto the transition section 12. With this arrangement, during use, the washer 3 is located between the clamping end face 14 and the structure to be assembled, protecting the contact end face of the structure and facilitating the even distribution of the axial load applied by the set screw 2 to the structure, thus avoiding stress concentration. For example, the washer 3 is made of a hardened gasket. The hardness of the washer 3 is 47-50 HRC.

[0046] like Figure 2 Combination Figure 4 As shown, a neck groove 17 is provided between the pre-tightening section 11 and the transition section 12. The neck groove 17 extends from the clamping end face 14 toward the side wall of the transition section 12. The neck groove 17 includes a first arcuate groove 171 and a second arcuate groove 172. The first arcuate groove 171 is located on the clamping end face 14. The second arcuate groove 172 is located on the side wall of the transition section 12. The first arcuate groove 171 and the second arcuate groove 172 transition smoothly. With this arrangement, the neck groove 17 serves two purposes: firstly, it provides axial auxiliary positioning for the assembly of the washer 3; secondly, the first arcuate groove 171 and the second arcuate groove 172 provide space for the deformation of the washer 3, which helps the washer 3 to more evenly transmit the axial clamping force applied by the set screw 2 to the structure to be assembled.

[0047] For example, based on the outer diameter of the transition section 12 on the connecting body 1, the radius of the first arc groove 171 is 5mm-7.5mm, and the radius of the second arc groove 172 is 3mm-5mm.

[0048] In addition to the aforementioned functions, the first and second arc-shaped grooves 171 and 172 also help reduce the processing difficulty of the connecting body 1. For example, the requirement for the straightness of the threaded through hole 16 can be reduced. When the axis of the threaded through hole 16 is offset towards the axis of the connecting body 1, the second arc-shaped groove 172 can prevent interference between the set screw 2 and the side wall of the transition section 12. This facilitates the application of axial force by the cylindrical section 21 of the set screw 2 to the structure to be assembled, thereby further improving the yield rate and reducing manufacturing costs.

[0049] like Figure 2 As shown, a groove 4 is provided between the transition section 12 and the connecting section 13. With this design, the groove 4 plays an important role in the external thread machining of the connecting section 13, such as chip removal, tool cooling, reduction of cutting force, improvement of machining accuracy and extension of tool life, which further improves the machining efficiency and quality of the external thread, and thus improves the strength of the bolt connection structure.

[0050] When using the high-strength anti-vibration and anti-loosening fastener proposed in this embodiment of the utility model, the connecting body 1 is inserted into the mounting hole of the structure to be assembled, and the connecting section 13 of the connecting body 1 is used to cooperate with the nut or directly cooperate with the mounting thread hole.

[0051] Compared with existing super nut structures, the high-strength vibration-resistant and anti-loosening fastener proposed in this embodiment of the invention has a greater preload force under the same tightening torque. For example, comparing the M20 thread of the connecting section 13 of the connecting body 1 and the M20 screw in the super nut, when the torque is 7 N·m, the preload force generated by the connecting body 1 is 51 KN, and the preload force generated by the screw is 47 KN; when the torque is 10 N·m, the preload force generated by the connecting body 1 is 84 KN, and the preload force generated by the screw is 80 KN.

[0052] This utility model is not limited to the specific technical solutions described in the above embodiments. Besides the above embodiments, this utility model may have other implementation methods. For those skilled in the art, any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A high-strength anti-vibration and anti-loosening fastener, characterized in that: It comprises a connecting body (1) and a set screw (2); The connecting body (1) comprises a pre-tightening section (11), a transition section (12) and a connecting section (13) which are connected in sequence, the pre-tightening section (11) being provided with a plurality of threaded through holes (16), a clamping end surface (14) being provided on a side of the pre-tightening section (11) close to the transition section (12), a tightening column (15) being provided on the pre-tightening section (11), the tightening column (15) being located between the plurality of threaded through holes (16), and an external thread being provided on a side wall of the connecting section (13); The set screw (2) is screwed into the threaded through hole (16) along a direction from the pre-tightening section (11) to the connecting section (13) on the connecting body (1), and a cylindrical section (21) is provided at the end of the set screw (2) for extending out of the threaded through hole (16).

2. The high-strength anti-vibration and anti-loosening fastener according to claim 1, characterized in that: It also comprises a gasket (3), wherein the gasket (3) is sleeved on the transition section (12).

3. The high-strength anti-vibration and anti-loosening fastener according to claim 1 or 2, characterized in that: A neck groove (17) is provided between the pre-tightening section (11) and the transition section (12), the neck groove (17) extending from the clamping end surface (14) toward the side wall of the transition section (12), the neck groove (17) comprising a first circular arc groove (171) and a second circular arc groove (172), the first circular arc groove (171) being located on the clamping end surface (14), the second circular arc groove (172) being located on the side wall of the transition section (12), and the first circular arc groove (171) and the second circular arc groove (172) being smoothly transitioned.

4. The high-strength anti-vibration and anti-loosening fastener according to claim 1, characterized in that: The tightening column (15) is coaxially arranged with the connecting body (1).

5. The high-strength anti-vibration and anti-loosening fastener according to claim 1, characterized in that: The threaded through holes (16) are arranged in a circular shape along the axis of the connecting body (1).

6. The high-strength anti-vibration and anti-loosening fastener according to claim 1, characterized in that: The tightening column (15) is a hexagonal section.

7. The high-strength anti-vibration and anti-loosening fastener according to claim 1, characterized in that: A waist groove (4) is provided between the transition section (12) and the connecting section (13).

8. The high-strength anti-vibration and anti-loosening fastener according to claim 3, characterized in that: The radius of the first circular arc groove (171) is 5 mm to 7.5 mm, and the radius of the second circular arc groove (172) is 3 mm to 5 mm.

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