Improved anti-loosening screw structure

Abstract

The utility model belongs to the technical field of anti -loose screw, disclose an improved anti -loose screw structure, including screw rod and the nut of screw rod thread cooperation connection, the threaded portion of screw rod is provided with at least one section of variable diameter area, and the thread root diameter of variable diameter area is periodic change, the internal thread of nut is provided with at least one elastic limit ring, and the partial area of elastic limit ring protrudes from the crest of nut internal thread, and is engaged with variable diameter area interference, and variable diameter area is located at the end of screw rod threaded portion, and the thread root diameter variation curve of variable diameter area is one of sawtooth wave, sine wave or square wave, and forms continuous wave crest and wave trough, and the inclination angle alpha of the side wall of wave trough near the loosening direction of nut. The utility model is through the periodic engagement interference of variable diameter area and elastic limit ring, forms mechanical interlock, and significantly improves the anti -loose ability, and breaks through the limitation of single friction anti -loose simultaneously, to be applicable to the environment of high vibration, impact load.

Description

Technical Field

[0001] This utility model relates to the field of anti-loosening screw technology, and in particular to an improved anti-loosening screw structure. Background Technology

[0002] Screws are the most common and critical connecting parts in many fields such as mechanical assembly, electronic equipment, furniture and building materials. However, traditional screws are prone to loosening or even falling off completely when subjected to long-term vibration, impact or alternating loads due to slight slippage between the threads. This can lead to equipment connection failure, performance degradation, or even safety accidents.

[0003] Currently, common anti-loosening technologies are mainly divided into the following categories: 1) Friction anti-loosening: such as using spring washers, double nuts, etc., relying on increasing the pressure between the threads to increase the friction force. However, this method has limited anti-loosening effect under strong vibration, and spring washers are prone to plastic deformation and failure.

[0004] 2) Mechanical locking and anti-loosening: such as using cotter pins and slotted nuts. Although this method is reliable, it is complex in structure, inconvenient to install, and requires high machining accuracy for nuts and screws. It is not suitable for miniaturized or space-constrained occasions.

[0005] 3) Chemical anti-loosening: such as applying thread-locking agent (screw glue) to the threads, but its effect is greatly affected by the quality and cleanliness of the glue, and it is difficult to disassemble and reuse. Therefore, we propose an improved anti-loosening screw structure. Utility Model Content

[0006] To address the technical problems existing in common anti-loosening technologies described in the background section, this utility model provides the following technical solution:

[0007] An improved anti-loosening screw structure includes a screw rod and a nut that is threadedly connected to the screw rod. The screw rod has at least one variable diameter region on its threaded portion, and the diameter of the thread root of the variable diameter region changes periodically.

[0008] At least one elastic limiting ring is provided in the internal thread of the nut. A portion of the elastic limiting ring protrudes from the crest of the internal thread of the nut and engages with and interferes with the variable diameter region.

[0009] As a technical solution of the improved anti-loosening screw structure of this utility model, the variable diameter area is located at the end of the screw thread.

[0010] As a technical solution for the improved anti-loosening screw structure of this utility model, the thread root diameter change curve of the variable diameter region is one of sawtooth wave, sine wave or square wave, and forms continuous peaks and troughs. The inclination angle α of the trough near the side wall of the nut loosening direction is greater than the inclination angle β of the side wall of the nut tightening direction.

[0011] As a technical solution for the improved anti-loosening screw structure of this utility model, the elastic limiting ring is a complete O-ring, and the elastic limiting ring is made of spring steel, copper alloy or high-performance engineering plastic material.

[0012] As a technical solution of the improved anti-loosening screw structure of this utility model, wherein: the internal thread of the nut is provided with annular grooves corresponding to the elastic limiting rings respectively, and the elastic limiting rings are embedded in the annular grooves.

[0013] As a technical solution of the improved anti-loosening screw structure of this utility model, the depth of the annular groove is greater than the wire diameter of the elastic limiting ring, so that the elastic limiting ring partially protrudes from the annular groove in its natural state.

[0014] As a technical solution for the improved anti-loosening screw structure of this utility model, the threads of the screw and the nut are one of standard metric threads, imperial threads, or trapezoidal threads.

[0015] Compared with the prior art, the present invention has at least the following beneficial effects:

[0016] 1. This utility model forms a mechanical interlock through the periodic meshing interference between the variable diameter region and the elastic limiting ring, which significantly improves the anti-loosening ability and breaks through the limitations of single friction anti-loosening, making it suitable for environments with high vibration and impact loads.

[0017] 2. This utility model can automatically compensate for the gap caused by thread wear or thermal expansion and contraction through the set elastic limit ring, so as to extend the service life. In addition, the waveform parameters of the variable diameter area are adjustable to adapt to the needs of different working conditions.

[0018] 3. This utility model reduces assembly steps by adopting a method that eliminates the need for auxiliary parts, and combined with the standardized thread design, it not only reduces processing difficulty but is also suitable for large-scale production. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Among them:

[0020] Figure 1 This is a schematic diagram of the overall main structure of this utility model.

[0021] Figure 2 This is a schematic diagram of the exploded structure of this utility model.

[0022] Figure 3 This is a cross-sectional view of the nut structure of this utility model.

[0023] Figure 4 For the present utility model Figure 3 Enlarged structural diagram at point A in the middle.

[0024] Explanation of reference numerals in the attached figures:

[0025] In the diagram: 1. Screw; 101. Variable diameter area; 2. Nut; 201. Annular groove; 202. Elastic limiting ring. Detailed Implementation

[0026] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0027] Reference Figures 1-4 An improved anti-loosening screw structure is provided, which includes a screw 1 and a nut 2 that is threadedly connected to the screw 1. The screw 1 is made of 45# steel with heat treatment (hardness HRC28-32), and the nut 2 is made of 304 stainless steel. The threaded part of the screw 1 is provided with at least one variable diameter region 101, and the thread root diameter of the variable diameter region 101 changes periodically.

[0028] At least one elastic limiting ring 202 is provided in the internal thread of nut 2. A portion of the elastic limiting ring 202 protrudes from the crest of the internal thread of nut 2 and meshes with the variable diameter region 101. In application, mechanical interlocking is formed by the periodic meshing interference between the variable diameter region 101 on screw 1 and the elastic limiting ring 202 on nut 2, which significantly improves the anti-loosening capability and is especially suitable for high-frequency vibration scenarios (such as mechanical transmission components).

[0029] Reference Figure 1 and Figure 2The variable diameter area 101 is located at the end of the threaded part of the screw 1. In application, the variable diameter area 101 is located at the end of the thread, so that after the nut 2 is tightened, the elastic limiting ring 202 can be directly inserted into the trough of the variable diameter wave, which simplifies the assembly process and accurately locks the final fastening position.

[0030] Reference Figure 1 and Figure 2 The thread root diameter change curve of the variable diameter region 101 is one of sawtooth wave, sine wave or square wave, forming continuous peaks and troughs. The inclination angle α of the side wall of the trough near the loosening direction of nut 2 is greater than the inclination angle β of the side wall near the tightening direction. If a sine wave thread root diameter change is used, the height difference between the peak and the trough is 0.1-0.3mm. The inclination angle α of the side wall near the loosening direction of the trough is 60°, and the inclination angle β of the side wall near the tightening direction is 30°, forming a "steep descent and slow rise" structure. In application, the sawtooth wave / sine wave and other waveform designs combined with the inclination angle difference (α>β) make the resistance in the loosening direction much greater than the resistance in the tightening direction, achieving a one-way locking effect, while taking into account both installation convenience and anti-loosening reliability.

[0031] Reference Figure 2 and Figure 3 The elastic limiting ring 202 is a complete O-ring, and is made of spring steel, copper alloy, or high-performance engineering plastic. For example, the elastic limiting ring 202 is made of 60Si2Mn spring steel (tempering temperature 400℃, ensuring elastic modulus ≥200GPa). The internal thread of the nut 2 has annular grooves 201 corresponding to the elastic limiting ring 202, and the elastic limiting ring 202 is embedded in the annular grooves 201. An annular groove 201 (groove depth 0.5mm, width 1.2mm) is formed, into which an elastic limiting ring 202 with a diameter of φ0.8mm (such as a spring steel wire O-ring, wire diameter tolerance ±0.05mm) is embedded. The ends of the annular groove 201 are machined with a 15° chamfer to prevent the elastic limiting ring 202 from sliding and shifting. In application, the elastic limiting ring 202 is made of fatigue-resistant material (such as spring steel) and embedded in the annular groove 201 to ensure elastic deformation space and prevent the elastic limiting ring 202 from falling off.

[0032] Reference Figure 3 and Figure 4 The depth of the annular groove 201 is greater than the wire diameter of the elastic limiting ring 202, so that the elastic limiting ring 202 protrudes partially from the annular groove 201 in its natural state. For example, if the protrusion of the elastic limiting ring 202 from the groove surface is 0.2mm in its natural state, it interferes with the variable diameter area 101 of the screw 1. In application, the protruding part of the elastic limiting ring 202 in its natural state continuously provides contact pressure, reducing the risk of instantaneous loosening caused by vibration.

[0033] Reference Figures 1-4The threads of screw 1 and nut 2 are one of the standard metric thread, imperial thread or trapezoidal thread. For example, the thread of screw 1 is a standard M6 metric thread with a pitch of 1mm, which can meet the needs of conventional assembly. In application, it can accommodate standard thread designs such as metric and imperial, so that the structure can seamlessly replace traditional screws. It is suitable for various scenarios such as precision assembly of electronic equipment (such as server racks) or heavy machinery (such as bridge fasteners).

[0034] The working principle of this utility model is as follows: Pre-alignment operation: Manually screw the nut 2 into the initial end of the screw 1 to ensure that the thread is not skewed. When the nut 2 is screwed into the starting point of the variable diameter area 101, the elastic limiting ring 202 begins to contact the threaded part on the screw 1.

[0035] Tightening operation: Use a tool to tighten nut 2 with a suitable torque (e.g., a torque wrench with a torque of 15-20 N·m). Since the angle β between the protruding part of the elastic limit ring 202 and the trough of the diameter-changing region 101 is small (e.g., 30°), the resistance increases gradually when tightening until nut 2 reaches the end of the diameter-changing region 101.

[0036] Anti-loosening locking stage: When the elastic limit ring 202 is inserted into the trough of the variable diameter area 101, a clear tactile feedback will be generated. At this time, the elastic limit ring 202 undergoes radial deformation due to waveform interference, providing continuous clamping force. At the same time, the steep side wall of the trough (such as α = 60°) prevents the nut 2 from rotating in the opposite direction and loosening.

[0037] Disassembly operation: When disassembling, a torque of 20% higher than the tightening torque (e.g., 18-24 N·m) needs to be applied to overcome the mechanical interlock between the elastic limit ring 202 and the trough. After rotating in the opposite direction to the starting point of the diameter-changing area 101, the nut 2 can be easily removed.

[0038] It should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of the technical solution of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. An improved anti-loosening screw structure, comprising a screw (1) and a nut (2) threadedly connected to the screw (1), characterized in that: The screw (1) has at least one variable diameter region (101) on its threaded portion, and the thread root diameter of the variable diameter region (101) changes periodically. At least one elastic limiting ring (202) is provided in the internal thread of the nut (2). A portion of the elastic limiting ring (202) protrudes from the crest of the internal thread of the nut (2) and engages with and interferes with the variable diameter region (101).

2. The improved anti-loosening screw structure according to claim 1, characterized in that: The variable diameter region (101) is located at the end of the threaded portion of the screw (1).

3. The improved anti-loosening screw structure according to claim 1, characterized in that: The thread root diameter change curve of the variable diameter region (101) is one of sawtooth wave, sine wave or square wave, and forms continuous peaks and valleys. The inclination angle α of the valley is close to the side wall of the nut (2) in the loosening direction, and is greater than the inclination angle β of the side wall close to the tightening direction.

4. The improved anti-loosening screw structure according to claim 1, characterized in that: The elastic limiting ring (202) is a complete O-ring, and the elastic limiting ring (202) is made of spring steel, copper alloy or high-performance engineering plastic.

5. The improved anti-loosening screw structure according to claim 1, characterized in that: The nut (2) has an annular groove (201) on its internal thread that corresponds to the elastic limiting ring (202), and the elastic limiting ring (202) is embedded in the annular groove (201).

6. The improved anti-loosening screw structure according to claim 5, characterized in that: The depth of the annular groove (201) is greater than the wire diameter of the elastic limiting ring (202), so that the elastic limiting ring (202) partially protrudes from the annular groove (201) in its natural state.

7. The improved anti-loosening screw structure according to claim 1, characterized in that: The threads of the screw (1) and the nut (2) are one of the following: standard metric thread, imperial thread, or trapezoidal thread.

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