Screw sleeve with expansion function

Abstract

The utility model discloses a threaded sleeve with an expansion function, relates to the technical field of threaded sleeves, and aims to solve the problems that threaded connection between the threaded sleeve and a base material possibly becomes loose gradually and even the threaded sleeve falls off from a prefabricated hole when the threaded sleeve is affected by factors such as vibration, impact load, severe temperature change or material creep for a long time. Comprising a screw sleeve body, the screw sleeve body comprises a self-tapping section and an expansion section, the top surface of the self-tapping section is provided with the expansion section for preventing falling and loosening, and the outer wall of the expansion section is provided with a plurality of groups of notches for assisting the expansion section to change the radius; according to the design of the expansion section, the inner groove in the inner wall and the notches in the screw flights are matched with the effect of a subsequent installation tool, radial expansion of the expansion section can be achieved, and the expansion section is in tight interference fit with the inner wall of a screw hole after the thread sleeve body is completely installed in place.

Description

Technical Field

[0001] This utility model relates to the field of threaded sleeve technology, and in particular to a threaded sleeve with an expansion function. Background Technology

[0002] Traditional self-tapping inserts often face challenges in practical applications. Since the fit between the insert and the pre-drilled hole mainly relies on the friction and mechanical engagement of the threads, the threaded connection between the insert and the base material may gradually loosen under prolonged exposure to factors such as vibration, impact loads, drastic temperature changes, or material creep. This can even cause the insert to fall out of the pre-drilled hole, leading to connection failure and affecting the reliability and safety of the equipment.

[0003] Therefore, this application provides a threaded sleeve with an expansion function to meet the requirements. Utility Model Content

[0004] The purpose of this application is to provide a threaded sleeve with an expansion function, which aims to solve the problem that the threaded connection between the threaded sleeve and the base material may gradually loosen or even cause the threaded sleeve to fall off the pre-made hole when subjected to factors such as vibration, impact load, drastic temperature changes or material creep for a long time.

[0005] To achieve the above objectives, this application provides the following technical solution: a threaded sleeve with an expansion function, comprising a threaded sleeve body, the threaded sleeve body comprising a self-tapping section and an expansion section, the top surface of the self-tapping section being provided with the expansion section for preventing detachment and loosening, and the outer wall of the expansion section being provided with multiple sets of notches for auxiliary expansion section radius variation.

[0006] Preferably, the inner wall of the expansion section is provided with an inner groove that is adapted to the thread of its outer wall. The inner groove is adapted to the thread of the outer wall of the expansion section, and the cross-section of the inner groove is a V-shaped structure.

[0007] Preferably, the notch is provided on the threaded edge of the outer wall thread of the expansion section.

[0008] Preferably, the notch is at least one of V-shape, U-shape, sawtooth shape, or semi-circle, and the depth of the notch is less than the pitch of the thread on the outer wall of the expansion section.

[0009] Preferably, the outer wall of the expansion section has at least three threads.

[0010] In summary, the technical effects and advantages of this utility model are as follows:

[0011] This invention features an expansion section design that, through the inner groove on the inner wall and the notch on the threaded edge, combined with the action of subsequent installation tools, enables radial expansion of the expansion section. This allows it to form a tight interference fit with the inner wall of the threaded hole after the threaded sleeve body is fully installed. This interference fit not only greatly enhances the thread engagement force between the threaded sleeve and the base body but also provides additional mechanical interlocking, effectively preventing the threaded sleeve from loosening or falling off due to factors such as vibration, impact, shear stress, or temperature changes, thereby significantly improving the reliability and durability of the threaded connection. Unlike simple self-tapping or pre-set threads, this invention triggers expansion by applying rotational pressure to the top surface of the threaded sleeve after installation, achieving independent control of the expansion process. This post-expansion design allows the threaded sleeve to smoothly enter during the tapping stage, and locking is performed after tapping is completed, avoiding undue interference from expansion during installation and ensuring smooth installation and a final locking effect. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 This is a schematic diagram of the structure of this utility model;

[0014] Figure 2 This is a cross-sectional structural diagram of the present invention;

[0015] Figure 3 For the present utility model Figure 2 A magnified structural diagram at point A in the diagram.

[0016] In the diagram: 1. Screw sleeve body; 2. Self-tapping section; 3. Expansion section; 300. Inner groove; 4. Notch. Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0018] Example 1: Reference Figure 1-3The screw insert shown includes a screw insert body 1, which includes a self-tapping section 2 and an expansion section 3. The expansion section 3 is provided on the top surface of the self-tapping section 2. During use, the self-tapping section 2 taps the thread through the cutting edge at the bottom. The expansion section 3 follows the self-tapping section 2 into the screw hole. In order to achieve effective locking and limit and prevent the screw insert body 1 from loosening and falling off, the expansion section 3 has an inner groove 300 provided on its inner wall and a notch on the screw edge, so that the thickness of the expansion section 3 is reduced and the radius is increased, thereby achieving radial expansion to increase the meshing force and prevent falling off.

[0019] As one implementation method in this embodiment, the V-shaped notch 4 is prone to forming a stress concentration point when subjected to radial compression or the axial component of the screwing torque, which can quickly achieve the radial expansion of the external thread.

[0020] As one implementation method in this embodiment, limiting the depth of the notch 4 to less than the thread pitch helps control the amount of expansion and prevents the threaded sleeve from expanding excessively during installation, which could lead to material fatigue or damage to the pre-drilled hole.

[0021] As one implementation method in this embodiment, the outer wall of the expansion section 3 has three thread turns to ensure uniform expansion.

[0022] Example 2: The difference between this example and Example 1 is that the notch 4 is U-shaped, which makes the stress distribution more uniform. When under stress, it can deform more smoothly and gradually, reducing the risk of material failure due to excessive local stress.

[0023] Example 3: The difference between this example and Example 1 is that the notch 4 is serrated. Its serrated tip can provide a certain degree of stress concentration, which helps to start the expansion. It can form a more effective interface friction and mechanical interlock with the inner wall of the pre-made hole, just like a wedge.

[0024] Example 4: The difference between this example and Example 1 is that the notch 4 is semi-circular, which can maintain the integrity of the structure to the greatest extent when subjected to force, and expand outward in the most gentle and uniform way.

[0025] The working principle of this utility model is as follows: By using a threaded insert tool, the threaded insert body 1 is installed into the threaded hole. After the threaded insert body 1 is installed in place, a tool of the same diameter as the threaded insert body 1 is used to press against the top surface of the threaded insert body 1 and rotate downward. The self-tapping section 2 limits the threaded insert body 1. When the tool rotates downward, the expansion section 3, through the design of the inner groove 300 and the notch 4, expands the radius of the expansion section 3 and forms an interference fit with the threaded hole, preventing the self-tapping threaded insert from falling out of the pre-drilled hole due to vibration or stress.

[0026] The electromechanical connections involved in this utility model are common practices used by those skilled in the art, and technical inspiration can be obtained through a limited number of experiments; they are common knowledge.

[0027] Components not described in detail in this article are existing technologies.

[0028] Finally, it should be noted that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A threaded sleeve with an expansion function, comprising a threaded sleeve body (1), characterized in that: The threaded sleeve body (1) includes a self-tapping section (2) and an expansion section (3). The top surface of the self-tapping section (2) is provided with the expansion section (3) to prevent it from falling off and loosening. The outer wall of the expansion section (3) is provided with multiple sets of auxiliary expansion section (3) with varying radii (4).

2. The threaded sleeve with expansion function according to claim 1, characterized in that: The inner wall of the expansion section (3) is provided with an inner groove (300) that is adapted to the thread of its outer wall. The inner groove (300) is adapted to the thread of the outer wall of the expansion section (3), and the cross section of the inner groove (300) is a V-shaped structure.

3. A threaded sleeve with expansion function according to claim 2, characterized in that: The notch (4) is provided on the thread edge of the outer wall thread of the expansion section (3).

4. A threaded sleeve with expansion function according to claim 3, characterized in that: The notch (4) is at least one of V-shape, U-shape, sawtooth shape, or semi-circle, and the depth of the notch (4) is less than the pitch of the thread on the outer wall of the expansion section (3).

5. A threaded sleeve with expansion function according to claim 3, characterized in that: The expansion section (3) has at least three turns of thread on its outer wall.

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