Self-locking nut

Abstract

The utility model relates to the field of mechanical locking, in particular to a self-locking nut. Comprising a nut body and a self-locking part, the self-locking part is arranged at the upper end of the nut body, the nut body is provided with an axially-through threaded hole, the inner wall of the nut body is provided with threads, the inner diameter of the threads of the self-locking part is smaller than that of the threads of the nut body, the outer side wall of the nut body is provided with a set of oppositely-arranged screwing parts, and the bottom of the nut body is provided with a flange part extending outwards in the radial direction. During fastening, the flange part interferes with threads of a fastening bolt to generate self-locking torque, fastening effect failure caused by loosening in work is prevented, meanwhile, the flange part can disperse axial loads in the fastening process, the loads are evenly applied to the surface of a to-be-fastened component, and the component is effectively prevented from being crushed.

Description

Technical Field

[0001] The utility model relates to the field of mechanical locking, in particular to a self-locking nut. Background Art

[0002] With the rapid development of modern industry, the requirements for fastening connections are becoming increasingly stringent. In fields such as aerospace, automotive manufacturing, and large-scale machinery, connectors must not only withstand immense tension, pressure, and vibration, but also exhibit reliable anti-loosening properties and long-term stability. Against this backdrop, self-locking nuts have emerged.

[0003] The working principle of self-locking nuts is to increase the friction of the threaded connection to achieve anti-vibration and anti-loosening functions. There are many types of self-locking nuts, mainly including those with embedded nylon rings, special thread bottoms, and metal anti-loosening devices. For the automotive manufacturing industry, self-locking nuts are often used in key parts such as engine systems. During the operation of automobile engines, they are often accompanied by harsh working conditions such as vibration, high and low temperature shocks, etc. These working conditions will cause thermal expansion and contraction, vibration loosening, overload and other adverse effects on fasteners. Therefore, automobile engines have higher load-bearing and anti-loosening requirements for fasteners than conventional fasteners. Conventional fasteners are difficult to meet the working needs of automobile engines. Therefore, a self-locking nut is needed to meet the working requirements of high load-bearing, high self-locking and vibration resistance. Utility Model Content

[0004] In order to overcome the deficiencies of the above-mentioned prior art, the utility model provides a self-locking nut, which solves the technical problem that ordinary nuts are difficult to meet the working requirements of high load-bearing, high self-locking and vibration resistance.

[0005] In order to achieve the above purpose, the present invention is implemented through the following technical solutions:

[0006] A self-locking nut comprises: a nut body and a self-locking portion, wherein the self-locking portion is arranged at the upper end of the nut body, a threaded hole is provided on the nut body, the threaded hole axially passes through the nut body and the self-locking portion, a thread is provided on the inner wall of the threaded hole, the inner diameter of the thread on the self-locking portion is smaller than the inner diameter of the thread on the nut body, a group of screwing portions is provided on the outer wall of the nut body, the group of screwing portions are arranged opposite to each other along the circumference of the nut body, a flange portion is provided at the bottom of the nut body, and the flange portion extends radially outward along the nut body.

[0007] Based on the above structure, the principle of the self-locking nut is as follows: the self-locking part is used to lock the self-locking nut on the fastening bolt of the component to be fastened, and the fastening bolt corresponds to the thread. Because the inner diameter of the thread on the self-locking part is smaller than the inner diameter of the thread on the nut body, when the fastening bolt is screwed to this position, the internal thread on the self-locking part and the fastening bolt thread will interfere with each other, thereby generating a self-locking torque, so that the self-locking nut is locked on the fastening bolt; the tightening part is used to cooperate with the wrench to rotate the self-locking nut for tightening operation; the flange part is used to evenly apply the load to the surface of the component to be fastened when the self-locking nut is subjected to a high axial load, effectively preventing the component to be fastened from being crushed by the self-locking nut.

[0008] Furthermore, in a self-locking nut of the present application, the flange portion includes a bearing surface, the bearing surface being umbrella-shaped and arranged radially toward the center of the threaded hole along the axial direction of the threaded hole. As a preferred embodiment of the present application, when the bearing surface of the self-locking nut of the present application is subjected to the expected load after the self-locking nut is assembled, the bearing surface deforms under the action of the clamping force load, completely conforming to the outer surface of the component to be fastened, more evenly distributing the load to the outer surface of the component to be fastened, and effectively preventing the orifice of the component to be fastened from being deformed by pressure during assembly of the self-locking nut.

[0009] Furthermore, in the present application, a self-locking nut is provided with a coating layer on the outside thereof, wherein the coating layer comprises: a first coating layer, wherein the first coating layer is provided on the surface of the self-locking nut. As a preferred embodiment of the present application, the first coating layer of the self-locking nut is used to improve the corrosion resistance of the self-locking nut and extend the service life of the self-locking nut. The first coating layer is evenly covered on the surface of the self-locking nut, thereby avoiding the problems of localized corrosion and rust. At the same time, the uniform first coating layer can also improve the overall quality and consistency of the self-locking nut.

[0010] Furthermore, in a self-locking nut in the present application, the coating layer further includes: a second coating layer, and the second coating layer is coated on the outer surface of the first coating layer. As a preferred embodiment of the present application, a self-locking nut in the present application has a relatively large surface friction coefficient, which is between 0.2 and 0.3, after the first coating layer is processed, so that the expected clamping force cannot be achieved under the specified installation torque. The second coating layer is used to adjust the friction coefficient of the self-locking nut to between 0.1 and 0.16. By adjusting the friction coefficient of the self-locking nut, the preload force can be controlled more accurately. When the friction coefficient is reduced, a greater preload force can be obtained under the same tightening torque, and vice versa. Such a design facilitates the precise adjustment of the preload force according to actual needs in different application scenarios to ensure the stability of the connection.

[0011] Furthermore, in a self-locking nut of the present application, the self-locking portion is elliptical in shape, and the thread comprises: a pair of mating threads, the pair of mating threads being arranged opposite to each other on the self-locking portion, the pair of mating threads being arranged concentrically with the thread, and the inner diameter of the pair of mating threads being smaller than the inner diameter of the thread. As a preferred embodiment of the present application, the self-locking portion of the self-locking nut of the present application is such that, during the tightening process, the self-locking nut is screwed onto the fastening bolt of the component to be tightened. Since the inner diameter of the pair of mating threads is smaller than the inner diameter of the thread, when the self-locking nut is screwed to this position, the mating threads and the fastening bolt have an interference fit, thereby locking the self-locking nut onto the fastening bolt of the component to be tightened.

[0012] Furthermore, in a self-locking nut of the present application, a chamfer is provided on one side of the flange portion near the self-locking portion, and the chamfer is provided along the circumference of the threaded hole. As a preferred embodiment of the present application, the chamfer in the self-locking nut of the present application is used to reduce stress concentration in the flange portion during use and extend the service life of the self-locking nut. The chamfer can make the stress distribution more uniform, reduce stress concentration, and improve the load-bearing capacity and durability of the self-locking nut; at the same time, it prevents crack propagation. When the self-locking nut is subjected to external force, cracks are easily generated at the sharp edges. The chamfer can change the direction of crack propagation, slow down the crack propagation speed, and improve the safety of the self-locking nut.

[0013] Furthermore, the self-locking nut in the present application is made of high-strength alloy steel, stainless steel, or aluminum alloy. As a preferred embodiment of the present application, the self-locking nut in the present application is made of high-strength alloy steel, stainless steel, or aluminum alloy, so that the self-locking nut has high strength, durability, and reliable connection performance.

[0014] It can be seen from the above technical solution that the utility model has the following beneficial effects:

[0015] The utility model provides a self-locking nut. Through the self-locking portion provided on the nut body, when the fastener is aligned, the internal thread of the self-locking portion interferes with the thread of the fastening bolt, thereby generating a self-locking torque, locking the self-locking nut on the fastening bolt, and preventing the self-locking nut from loosening during operation, resulting in failure of the fastening effect; at the same time, during the tightening process of the self-locking nut, the design of the flange portion is conducive to dispersing the axial load, evenly applying the axial load to the surface of the component to be fastened, and effectively preventing the component to be fastened from being crushed by the self-locking nut. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of a three-dimensional structure of a self-locking nut in an embodiment of the present application;

[0017] Figure 2 This is a schematic diagram of the planar structure of a self-locking nut in an embodiment of the present application;

[0018] Figure 3 for Figure 2 Sectional view of the AA section.

[0019] In the figure: 1-nut body; 10-threaded hole; 101-thread; 1011-matching thread; 2-self-locking part; 3-screw-on part; 4-flange part; 41-bearing surface; 42-chamfer; 5-coating layer; 51-first coating layer; 52-second coating layer. DETAILED DESCRIPTION

[0020] like Figure 1 、 2 As shown in Figure 3, a self-locking nut comprises: a nut body 1, a self-locking portion 2, the self-locking portion 2 is arranged at the upper end of the nut body 1, the nut body 1 is provided with a threaded hole 10, the threaded hole 10 axially passes through the nut body 1 and the self-locking portion 2, the inner wall of the threaded hole 10 is provided with a thread 101, the inner diameter of the thread 101 on the self-locking portion 2 is smaller than the inner diameter of the thread 101 on the nut body 1, a group of screwing portions 3 are provided on the outer wall of the nut body 1, and the group of screwing portions 3 are relatively arranged along the circumference of the nut body 1, and a flange portion 4 is provided at the bottom of the nut body 1, and the flange portion 4 extends radially outward along the nut body 1.

[0021] Based on the above structure, the principle of the self-locking nut is as follows: the self-locking portion 2 is used to lock the self-locking nut onto the fastening bolt of the component to be fastened (not shown), and the fastening bolt corresponds to the thread 101. Because the inner diameter of the thread 101 on the self-locking portion 2 is smaller than the inner diameter of the thread 101 on the nut body 1, when the fastening bolt is screwed to this position, the internal thread on the self-locking portion 2 and the fastening bolt thread will interfere, thereby generating a self-locking torque, locking the self-locking nut onto the fastening bolt; the screwing portion 3 is used to cooperate with a wrench to rotate the self-locking nut for tightening; the flange portion 4 is used to evenly apply the load to the surface of the component to be fastened when the self-locking nut is subjected to a high axial load, effectively preventing the component to be fastened from being crushed by the self-locking nut. The number of screwing portions 3 in a group is 6, and a group of screwing portions 3 is arranged in a closed manner along the circumference of the nut body 1.

[0022] In this embodiment, the flange portion 4 includes an umbrella-shaped bearing surface 41, which is arranged axially along the threaded hole 10 and radiates toward the center of the threaded hole 10. When the self-locking nut is assembled and subjected to the expected load, the bearing surface 41 deforms under the clamping force, completely conforming to the outer surface of the fastened component. This more evenly distributes the load across the outer surface of the fastened component and effectively prevents the opening of the fastened component from being deformed during assembly. The bearing surface 41 is arranged at an angle of 1° to the horizontal and radiates axially along the threaded hole 10 and toward the center of the threaded hole 10.

[0023] In this embodiment, the exterior of the self-locking nut is coated with a coating layer 5. This coating layer 5 comprises a first coating layer 51, which is applied to the surface of the self-locking nut. The first coating layer 51 is used to improve the corrosion resistance of the self-locking nut and extend its service life. The first coating layer 51 evenly covers the surface of the self-locking nut, preventing localized corrosion and rust. Furthermore, the uniform first coating layer 51 also improves the overall quality and consistency of the self-locking nut. The first coating layer 51 is galvanized with a thickness of ≥7μm.

[0024] In this embodiment, the coating layer 5 also includes: a second coating layer 52, which is applied to the outer surface of the first coating layer 51. After the self-locking nut is processed with the first coating layer 51, the surface friction coefficient is relatively large, between 0.2 and 0.3, so that the expected clamping force cannot be achieved under the specified installation torque. The second coating layer 52 is used to adjust the friction coefficient of the self-locking nut to between 0.1 and 0.16. By adjusting the friction coefficient of the self-locking nut, the preload force can be more accurately controlled. When the friction coefficient is reduced, a greater preload force can be obtained under the same tightening torque, and vice versa. This design facilitates the precise adjustment of the preload force according to actual needs in different application scenarios to ensure the stability of the connection. The second coating layer 52 uses aviation lubricant.

[0025] In this embodiment, the self-locking portion 2 is elliptical in shape, and the thread 101 includes a pair of mating threads 1011. The pair of mating threads 1011 are disposed opposite each other on the self-locking portion 2, are disposed concentrically with the thread 101, and have an inner diameter that is smaller than the inner diameter of the thread 101. During the tightening process of the self-locking portion 2, the self-locking nut is screwed onto the fastening bolt of the component to be tightened. Because the inner diameter of the pair of mating threads 1011 is smaller than the inner diameter of the thread 101, when the self-locking nut is screwed to this position, the mating threads 1011 and the fastening bolt form an interference fit, thereby locking the self-locking nut on the fastening bolt of the component to be tightened. The nut body 1 and the self-locking part 2 are processed as one piece. At this time, the shape of the self-locking part 2 is circular. After the thread 101 is processed, a closing device (not shown) is used to deform the self-locking part 2 from a circular clamping and extrusion into an elliptical shape, so that the thread inside the self-locking part 2 is also deformed, and the inner diameter of the thread inside the self-locking part 2 becomes smaller than the original inner diameter of the thread 101.

[0026] In this embodiment, the flange portion 4 is provided with a chamfer 42 on one side proximal to the self-locking portion 2. The chamfer 42 is arranged circumferentially along the threaded hole 10. The chamfer 42 is used to reduce stress concentration on the flange portion 4 during use, thereby extending the service life of the self-locking nut. The chamfer 42 can make stress distribution more uniform, reduce stress concentration, and improve the load-bearing capacity and durability of the self-locking nut. It also prevents crack propagation. When a self-locking nut is subjected to external forces, cracks are easily generated at sharp edges. The chamfer 42 can change the direction of crack propagation, slowing the crack propagation rate and improving the safety of the self-locking nut.

[0027] In this embodiment, the self-locking nut is made of high-strength alloy steel, stainless steel, or aluminum alloy. The self-locking nut is made of high-strength alloy steel, stainless steel, or aluminum alloy, resulting in high strength, durability, and reliable connection performance. The self-locking nut is made of 21CrMoV5-7 alloy steel. Strengthened by alloying elements, 21CrMoV5-7 has high strength and can withstand heavy loads; good heat resistance and the ability to maintain its mechanical properties at higher temperatures; a certain toughness that can withstand impact loads without brittle fracture; and good machinability.

[0028] The above description of the technical principles of the present invention in conjunction with specific embodiments is intended solely to illustrate the principles of the present invention and is not to be construed in any way as limiting the scope of protection of the present invention. Based on the explanations herein, those skilled in the art will be able to devise other specific implementations of the present invention without inventive effort, and such implementations will fall within the scope of protection of the present invention.

Claims

1. A self-locking nut, characterized in that: include: A nut body (1), a self-locking portion (2), the self-locking portion (2) being arranged at the upper end of the nut body (1), a threaded hole (10) being provided on the nut body (1), the threaded hole (10) axially passing through the nut body (1) and the self-locking portion (2), a thread (101) being provided on the inner wall of the threaded hole (10), the inner diameter of the thread (101) on the self-locking portion (2) being smaller than the inner diameter of the thread (101) on the nut body (1), a group of screwing portions (3) being provided on the outer wall of the nut body (1), the group of screwing portions (3) being arranged opposite to each other along the circumference of the nut body (1), a flange portion (4) being provided at the bottom of the nut body (1), the flange portion (4) extending radially outward along the nut body (1).

2. A self-locking nut according to claim 1, characterized in that: The flange portion (4) comprises a bearing surface (41), the bearing surface (41) being umbrella-shaped and radially arranged along the axial direction of the threaded hole (10) toward the center of the threaded hole (10).

3. The self-locking nut according to claim 1, characterized in that: The outer side of the self-locking nut is covered with a coating layer (5), and the coating layer (5) comprises: a first coating layer (51), and the first coating layer (51) is covered on the surface of the self-locking nut.

4. The self-locking nut according to claim 3, characterized in that: The coating layer (5) further comprises: a second coating layer (52), wherein the second coating layer (52) is coated on the outer surface of the first coating layer (51).

5. The self-locking nut according to claim 1, characterized in that: The self-locking portion (2) is elliptical in shape, and the thread (101) comprises: a pair of mating threads (1011), the pair of mating threads (1011) being arranged relatively on the self-locking portion (2), the pair of mating threads (1011) being arranged concentrically with the thread (101), and the inner diameter of the pair of mating threads (1011) being smaller than the inner diameter of the thread (101).

6. The self-locking nut according to claim 1, characterized in that: The flange portion (4) is provided with a chamfer (42) on one side near the self-locking portion (2), and the chamfer (42) is provided in a closed circumferential direction along the threaded hole (10).

7. The self-locking nut according to claim 1, characterized in that: The self-locking nut is made of high-strength alloy steel, stainless steel or aluminum alloy.

Images