Anti-retreating self-locking screw

Abstract

The invention belongs to the technical field of fasteners, and particularly provides an anti-retreating self-locking screw which comprises a screw head and a screw rod connected with the screw head, an external thread is arranged on the screw rod, and the anti-retreating self-locking screw is characterized in that the thread form of the external thread is of an asymmetric structure, the thread face close to one side of the screw head is a locking face, and the locking face is a locking face. A locking surface is arranged on one side of the screw head, the included angle between the locking surface and the axis of the screw rod is 5-8 degrees, a thread surface on one side far away from the screw head is a guide surface, and the included angle between the guide surface and the axis of the screw rod is 15-20 degrees. The anti-loosening capacity and the self-locking reliability of the screw are further improved, and the screw can effectively cope with worse working conditions such as vibration and impact.

Description

Technical Field

[0001] This invention relates to the field of insect trap technology, specifically to a self-locking screw that resists disengagement. Background Technology

[0002] Screws, as commonly used fasteners, play a vital role in connecting and fixing various machines, equipment, and structures. However, in practical applications, traditional screws often loosen and de-thread due to factors such as vibration, impact, and temperature changes. This not only affects the normal operation of equipment but can also lead to safety accidents in severe cases. Furthermore, in certain special environments, such as humid or corrosive media, screws also face problems such as poor sealing performance and susceptibility to corrosion, further shortening their service life and increasing maintenance costs.

[0003] Currently, various solutions have been adopted in existing technologies to address the problem of screw loosening. For example, using anti-loosening nuts in conjunction with screws increases the friction between the threads to prevent loosening. However, this method increases the number of parts and installation costs, and is inconvenient to apply in space-constrained situations. Another approach is to apply anti-loosening adhesive to the screw threads, utilizing the adhesive's stickiness to prevent loosening. However, its effectiveness is greatly affected by the adhesive's properties and the usage environment, and it is difficult to reuse after disassembly. Some methods employ irregular thread structures, such as triangular or trapezoidal thread cross-sections, which can improve anti-loosening capabilities to some extent, but are difficult to manufacture, and the self-locking effect still needs improvement. Furthermore, for sealing and corrosion prevention, existing solutions often involve adding additional seals or surface treatments, but these suffer from poor fit with the screw and short-lived effects. Based on these issues, a self-locking anti-loosening screw is proposed. Summary of the Invention

[0004] This invention addresses the technical problems mentioned in the background by developing a self-locking screw that is simple in structure, easy to install, has excellent anti-retrofit performance, is reusable, and also has good sealing and corrosion resistance.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows: A self-locking screw with anti-retraction capability includes a screw head and a screw rod connected to the screw head. The screw rod is provided with an external thread. The external thread has an asymmetrical tooth profile. The tooth surface near the screw head is a locking surface, and the angle between the locking surface and the screw rod axis is 5°-8°. The tooth surface away from the screw head is a guide surface, and the angle between the guide surface and the screw rod axis is 15°-20°. The screw has an elastic locking ring at the end of the external thread, and the outer diameter of the elastic locking ring is larger than the major diameter of the external thread. A sealing ring is provided at the connection between the screw head and the screw rod, and the outer diameter of the sealing ring is slightly larger than the outer diameter of the screw head.

[0006] A further improvement is that a ceramic coating is provided on the outer surface of the screw and the outer surface of the screw head, and the thickness of the ceramic coating is 5-10μm.

[0007] A further improvement is that the depth of the adapter groove is 1-2 mm.

[0008] A further improvement is that the elastic locking ring is made of a metal material with good elasticity, preferably spring steel.

[0009] A further improvement is that the outer diameter of the elastic locking ring is 0.1-0.3 mm larger than the major diameter of the external thread.

[0010] A further improvement is that the end face of the screw head is provided with an internal hexagonal groove, and the inner wall of the internal hexagonal groove is provided with several evenly distributed anti-slip protrusions.

[0011] A further improvement is that the number of anti-slip protrusions is 6-8.

[0012] A further improvement is that the bottom of the internal hexagonal recess is provided with an adapter groove, the shape of which matches the head of a commonly used Phillips screwdriver. A further improvement is that the height of the anti-slip protrusion is 0.2-0.4mm.

[0013] A further improvement is that the sealing ring is made of an oil- and water-resistant rubber material with a circular cross-section, preferably nitrile rubber.

[0014] A further improvement is that the outer diameter of the sealing ring is 0.5-1mm larger than the outer diameter of the screw head.

[0015] A further improvement is that the screw head and the screw rod are integrally formed.

[0016] Compared with the prior art, the technical solution provided by this invention has the following advantages: Based on the original asymmetric thread profile and the dual function of the elastic locking ring, this invention allows all structures to work together, further improving the screw's anti-loosening ability and self-locking reliability, and effectively coping with more severe vibration, impact and other working conditions.

[0017] The newly added sealing ring structure of this invention can effectively prevent the medium from seeping in, improve the applicability of screws in humid and fluid environments, and reduce connection failure problems caused by medium corrosion. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 For the present invention Figure 1 Side view; Figure 3 For the present invention Figure 1 A sectional view; Figure 4 For the present invention Figure 1 Another perspective structural diagram.

[0019] Figure label: 1. Screw head; 2. Screw; 21. Locking surface; 22. Guide surface; 3. Elastic locking ring; 4. Sealing ring; 5. Internal hexagonal groove; 6. Anti-slip protrusion; 7. Adaptor groove. Detailed Implementation

[0020] To facilitate understanding of the present invention, a more complete description of the invention will be given below with reference to the accompanying drawings, which illustrate several embodiments of the invention. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of the invention will be more thorough and complete.

[0021] In this invention, unless otherwise explicitly specified and limited, the terms "installed," "connected," "linked," "fixed," and "equipped" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0022] It should be noted that the structures not described in this invention do not involve the design points and improvement directions of this invention, and all adopt existing technology. At the same time, the content in the above background technology is within the scope of the inventor's technical knowledge. Since the technical content in this field is vast and too complex, the above content of this application does not necessarily constitute prior art. In addition, the technical features involved in the different embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0023] Reference Figure 1-4 , refer to Figure 1-4This invention proposes an anti-loosening self-locking screw, comprising a screw head 1 and a screw rod 2 connected to the screw head 1. The screw rod 2 is provided with an external thread, the thread profile of which is asymmetrical. The thread surface near the screw head 1 is the locking surface 21, the angle between the locking surface 21 and the axis of the screw rod 2 is 5°-8°, and the thread surface away from the screw head 1 is the guide surface 22, the angle between the guide surface 22 and the axis of the screw rod 2 is 15°-20°. Through this asymmetrical thread profile design, when the screw is tightened, the locking surface 21 can closely fit with the internal thread surface of the nut or the connected part, increasing the friction and effectively preventing loosening; while the guide surface 22 facilitates the installation and screwing in of the screw. An elastic locking ring 3 is provided at the end of the external thread on the screw 2. The outer diameter of the elastic locking ring 3 is larger than the major diameter of the external thread. When the screw is fully tightened, the elastic locking ring 3 will elastically deform with the end face of the nut or the connected part, forming a certain axial preload, which further enhances the self-locking ability of the screw. At the same time, under vibration and other working conditions, the elastic locking ring 3 can absorb some energy and reduce the tendency of the screw to loosen. A sealing ring 4 is provided at the connection between the screw head 1 and the screw rod 2. The outer diameter of the sealing ring 4 is slightly larger than the outer diameter of the screw head 1. When the screw is tightened, the sealing ring 4 can fit tightly against the surface of the connected parts, effectively preventing liquids, gases and other media from seeping in from the connection gap, thus improving the sealing performance of the screw. It is suitable for working environments with humid conditions and fluids.

[0024] In a preferred embodiment, both the outer surface of the screw 2 and the outer surface of the screw head 1 are provided with a ceramic coating. The thickness of the ceramic coating is 5-10 μm. The ceramic coating has excellent corrosion resistance, wear resistance and high temperature resistance, which can protect the screw from external corrosive media, extend the service life of the screw, and enable it to work stably in highly corrosive environments such as chemical and marine environments.

[0025] In a preferred embodiment, the elastic locking ring 3 is made of a metal material with good elasticity, preferably spring steel.

[0026] In a preferred embodiment, the outer diameter of the elastic locking ring 3 is 0.1-0.3 mm larger than the major diameter of the external thread.

[0027] In a preferred embodiment, the end face of the screw head 1 is provided with an internal hexagonal groove 5, and the inner wall of the internal hexagonal groove 5 is provided with a plurality of evenly distributed anti-slip protrusions 6. The anti-slip protrusions 6 can increase the friction between the wrench and the screw head 1, prevent slippage during tightening or disassembly, and improve the reliability of operation. The number of anti-slip protrusions 6 is preferably 6-8.

[0028] In a preferred embodiment, the bottom of the internal hexagonal recess 5 is provided with an adapter groove 7. The shape of the adapter groove 7 matches the head of a commonly used Phillips screwdriver. The adapter groove 7 allows the screw to be operated not only with an internal hexagonal wrench but also with a Phillips screwdriver, improving the adaptability of the screw under different tool conditions and increasing the flexibility of operation. The depth of the adapter groove 7 is preferably 1-2mm.

[0029] In a preferred embodiment, the height of the anti-slip protrusion 6 is 0.2-0.4 mm.

[0030] In a preferred embodiment, the sealing ring 4 is made of an oil- and water-resistant rubber material with a circular cross-section, preferably nitrile rubber.

[0031] In a preferred embodiment, the outer diameter of the sealing ring 4 is 0.5-1 mm larger than the outer diameter of the screw head 1.

[0032] In a preferred embodiment, the screw head 1 and the screw 2 are integrally formed.

[0033] The invention will now be described in detail in conjunction with the screw manufacturing process: According to the design requirements, the screw head 1, screw 2 (including external thread), elastic locking ring 3, sealing ring 4 and other parts are manufactured separately. Among them, the external thread is processed with special equipment to form an asymmetrical tooth profile. The elastic locking ring 3 is made of spring steel by stamping or forging. The sealing ring 4 is molded from nitrile rubber. The screw head 1 is machined with an internal hexagonal groove 5, an anti-slip protrusion 6 and an adapter groove 7. Finally, the outer surfaces of the screw 2 and the screw head 1 are treated with ceramic coating. The elastic locking ring 3 is fixed to the end of the external thread of the screw 2 to ensure its accurate position; the sealing ring 4 is installed at the connection between the screw head 1 and the screw 2 to ensure a tight fit between the sealing ring 4 and the screw; since the screw head 1 and the screw 2 are integrally formed, no additional connection process is required.

[0034] The assembled screws undergo various performance tests, including the accuracy of the external thread dimensions, the elastic performance of the elastic locking ring 3, the sealing performance of the sealing ring 4, the thickness and quality of the ceramic coating, and the integrity of the overall structure, to ensure that the product meets the design requirements. Install the qualified screws onto the corresponding connected parts according to the above installation steps to complete the connection and fixation.

[0035] The present invention will be specifically described below using the screw manufacturing and installation process: Ensure that the thread hole specifications of the connected parts match the external thread of the screw, clean the impurities and debris in the thread hole, and check whether each part of the screw is intact, such as whether the sealing ring 4 is damaged or the elastic locking ring 3 is deformed.

[0036] Depending on the actual situation, choose either an Allen wrench or a Phillips screwdriver. If using an Allen wrench, insert the wrench into the Allen groove 5. The anti-slip protrusions 6 on the inner wall of the groove increase friction and prevent slippage. If using a Phillips screwdriver, simply insert its head into the adapter slot 7.

[0037] With a handheld tool, align the screw shank 2 with the threaded hole of the part to be connected. Utilize the 15°-20° (e.g., 17°) angle between the external thread guide surface 22 and the axis of the screw shank 2 to easily screw the screw into the threaded hole. During the screwing process, the guide surface 22 plays a good guiding role, reducing the screwing resistance and making the installation more convenient.

[0038] Continue turning the tool. As the screw penetrates deeper, the locking surface 21 of the external thread gradually contacts the tooth surface of the internal thread of the connected part. Because the angle between the locking surface 21 and the axis of the screw 2 is 5°-8° (e.g., 6°), which is relatively steep, it can fit tightly against the tooth surface of the internal thread during tightening, generating a large frictional force. When the sealing ring 4 of the screw head 1 contacts the surface of the connected part, continue to apply a certain force to cause the sealing ring 4 to undergo elastic deformation and fit tightly against the surface of the connected part. At the same time, the elastic locking ring 3 at the end of the screw 2 also begins to contact the end face of the connected part and undergoes elastic deformation, forming an axial preload until the screw is completely tightened and fixed.

[0039] The above-described embodiments are merely illustrative of certain implementations of the present invention, and are described in a relatively specific and detailed manner. However, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements are all within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A self-locking screw with anti-retraction capability, comprising a screw head and a shank connected to the screw head, wherein the shank has an external thread, characterized in that: The external thread has an asymmetrical tooth profile. The tooth surface near the screw head is the locking surface, and the angle between the locking surface and the screw axis is 5°-8°. The tooth surface away from the screw head is the guide surface, and the angle between the guide surface and the screw axis is 15°-20°. The screw has an elastic locking ring at the end of the external thread, and the outer diameter of the elastic locking ring is larger than the major diameter of the external thread. A sealing ring is provided at the connection between the screw head and the screw rod, and the outer diameter of the sealing ring is slightly larger than the outer diameter of the screw head.

2. The anti-retraction self-locking screw according to claim 1, characterized in that: The outer surface of the screw and the outer surface of the screw head are both provided with a ceramic coating, the thickness of which is 5-10μm.

3. The anti-retraction self-locking screw according to claim 1, characterized in that: The elastic locking ring is made of a metal material with good elasticity.

4. The anti-retraction self-locking screw according to claim 1, characterized in that: The outer diameter of the elastic locking ring is 0.1-0.3 mm larger than the major diameter of the external thread.

5. The anti-retraction self-locking screw according to claim 1, characterized in that: The end face of the screw head is provided with an internal hexagonal groove, and the inner wall of the internal hexagonal groove is provided with several evenly distributed anti-slip protrusions.

6. The anti-retraction self-locking screw according to claim 5, characterized in that: The height of the anti-slip protrusion is 0.2-0.4mm.

7. The anti-retraction self-locking screw according to claim 5, characterized in that: The bottom of the internal hexagonal recess is provided with an adapter groove, the shape of which matches the head of the Phillips screwdriver.

8. The anti-retraction self-locking screw according to claim 1, characterized in that: The sealing ring is made of rubber material and has a circular cross-section.

9. The anti-retraction self-locking screw according to claim 1, characterized in that: The outer diameter of the sealing ring is 0.5-1 mm larger than the outer diameter of the screw head.

10. The anti-retraction self-locking screw according to claim 1, characterized in that: The screw head and screw rod are integrally formed.

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