Hex socket head cap screws

Abstract

This utility model discloses an internal hexagonal head screw, including a screw head, a screw rod, and an expansion assembly. The screw head is hexagonal with an internal hexagonal turning groove at the top. A screw rod is fixed to the bottom of the screw, and an expansion assembly is fitted around the screw rod. The expansion assembly consists of an upper fixing ring, a lower fixing ring, and arc-shaped strips. Both the upper and lower fixing rings are fitted around the screw rod, with the upper fixing ring positioned above the lower fixing ring. Several outwardly protruding arc-shaped strips connect the upper and lower fixing rings, and the upper fixing ring is fixed to the screw head. This utility model, by fitting an outwardly expanding expansion assembly around the screw rod, allows the expansion assembly to expand outward during tightening, increasing the friction between the screw and the connected components. This results in excellent anti-loosening performance after tightening, making the screw less prone to loosening.

Description

Technical Field

[0001] This utility model relates to the technical field of fasteners, and in particular to the technical field of screws. Background Technology

[0002] Screws are required for fastening and preventing loosening in various fields. However, ordinary screws are prone to loosening under strong vibrations, which can affect the service life of machinery, mechanical safety, and personal safety. Therefore, anti-loosening screws are needed in these situations. Existing anti-loosening screws mainly employ friction anti-loosening and permanent anti-loosening methods. Friction anti-loosening uses anti-slip washers, but its effectiveness is not ideal and cannot meet the requirements of applications with high anti-loosening performance. Permanent anti-loosening uses spot welding, riveting, or bonding. While these methods offer good anti-loosening effects, they often damage the screw during disassembly, rendering it unusable.

[0003] Existing patent CN120402505A discloses a screw anti-loosening structure with a spring-loaded cone, including a screw that passes through a first connected member and is threadedly connected to a second connected member. The lower section of the screw is a locking section, which is threadedly connected to the second connected member. The locking section has a first conical hole, and the threaded hole of the second connected member has a convex cone that mates with the first conical hole. The smaller end of the convex cone faces the head of the screw, and the larger end of the convex cone is fixed with a spring, which is connected to the second connected member. The wall of the first conical hole has a gap, which is distributed along the axial direction of the screw and extends to the bottom of the screw at one end. With this anti-loosening structure, after the screw is tightened, the expansion of the locking section is irreversible, and the screw cannot be removed without damaging the mating internal thread, making it difficult to reuse the connected parts and the screw. Summary of the Invention

[0004] The purpose of this invention is to solve the problems in the prior art by proposing an internal hexagonal head screw that provides excellent anti-loosening effect, allows for repeated disassembly and assembly, and does not damage the components connected to the screw during the disassembly process.

[0005] To achieve the above objectives, this utility model proposes an internal hexagonal head screw, comprising a screw head, a screw rod, and an expansion assembly. The screw head is hexagonal, with an internal hexagonal turning groove at the top. A screw rod is fixed to the bottom of the screw, and an expansion assembly is fitted around the screw rod. The expansion assembly consists of an upper fixing ring, a lower fixing ring, and arc-shaped strips. Both the upper and lower fixing rings are fitted around the screw rod, with the upper fixing ring positioned above the lower fixing ring. Several outwardly protruding arc-shaped strips connect the upper and lower fixing rings, and the upper fixing ring is fixed to the screw head.

[0006] Preferably, the lower end face of the screw head is provided with anti-slip texture.

[0007] Preferably, the lower part of the screw is a guide platform, which is in the shape of an inverted frustum cone, and the outer diameter of the guide platform gradually decreases from top to bottom.

[0008] Preferably, the lower end of the screw head is provided with an annular groove, and the upper fixing ring is located in the annular groove.

[0009] Preferably, the inner diameters of both the upper and lower fixing rings are larger than the outer diameter of the screw, and the upper fixing ring and the screw head are welded together.

[0010] Preferably, the outer wall of the arc-shaped strip has a frosted surface.

[0011] The beneficial effects of this utility model are as follows: By fitting an outwardly expandable expansion component around the outside of the screw, the expansion component can expand outward during the tightening process, which increases the friction between the screw and the connected component, giving the screw excellent anti-loosening performance after tightening and making it less prone to loosening.

[0012] The features and advantages of this utility model will be described in detail through embodiments and accompanying drawings. Attached Figure Description

[0013] Figure 1 This is a front view of the internal hexagonal head screw of this utility model.

[0014] In the diagram: 1-Screw head, 2-Screw, 4-First component, 5-Second component, 10-Hex socket head cap screwing groove, 11-Annular groove, 20-Guide platform, 30-Arc strip, 31-Upper fixing ring, 32-Lower fixing ring, 40-Through hole, 50-Threaded hole. Detailed Implementation

[0015] Example 1:

[0016] See Figure 1This utility model relates to an internal hexagonal head screw, comprising a screw head 1, a screw rod 2, and an expansion assembly. The screw head 1 is hexagonal, and the top of the screw head 1 is provided with an internal hexagonal turning groove 10. A screw rod 2 is fixed to the bottom of the screw, and an expansion assembly is fitted around the outside of the screw rod 2. The expansion assembly consists of an upper fixing ring 31, a lower fixing ring 32, and arc-shaped strips 30. The upper fixing ring 31 and the lower fixing ring 32 are both fitted around the outside of the screw rod 2, with the upper fixing ring 31 located above the lower fixing ring 32. Several outwardly protruding arc-shaped strips 30 are connected between the upper fixing ring 31 and the lower fixing ring 32. The upper fixing ring 31 is fixed to the screw head 1.

[0017] Screws are used to connect the first component 4 and the second component 5. The first component 4 has a through hole 40 that allows the expansion assembly in its initial state to pass through. The initial length of the arc strip 30 is greater than the length of the through hole 40. The second component 5 has a threaded hole 50 that mates with the screw 2.

[0018] The inner diameter of the upper fixing ring 31 and the inner diameter of the lower fixing ring 32 are both larger than the outer diameter of the screw 2. The upper fixing ring 31 and the screw head 1 are welded together.

[0019] Example 2:

[0020] In order to increase the friction between the screw head 1 and the first component 4, and thus improve the anti-loosening performance, the lower end face of the screw head 1 is provided with anti-slip texture.

[0021] In order to prevent the upper fixing ring 31 from affecting the fit between the screw head 1 and the first component 4, the lower end of the screw head 1 is provided with an annular groove 11, and the upper fixing ring 31 is located in the annular groove 11.

[0022] Example 3:

[0023] In order to allow the screw 2 to be easily inserted into the threaded hole 50 in a non-visual state, the lower part of the screw 2 is a guide platform 20, which is in the shape of an inverted frustum cone, and the outer diameter of the guide platform 20 gradually decreases from top to bottom.

[0024] Example 4:

[0025] In order to increase the friction between the arc-shaped strip 30 and the first component 4, and thus improve the anti-loosening performance, the outer wall of the arc-shaped strip 30 is frosted.

[0026] The working process of this utility model:

[0027] In operation, the screw shank 2 of this utility model passes through the through hole 40 of the first component 4 and screws onto the threaded hole 50 of the second component 5. The expansion assembly also extends into the through hole 40. As the screw is turned, the upper retaining ring 31 of the expansion assembly is pressed against the screw head 1, and the lower retaining ring 32 of the expansion assembly is pressed against the second component 5. The arc-shaped strip 30 bends outward as the screw is turned. During the bending process, the arc-shaped strip 30 will be in close contact with the inner wall of the through hole 40, so that the friction between the arc-shaped strip 30 and the inner wall of the through hole 40 gradually increases. When the screw is fully tightened, due to the large static friction between the arc-shaped strip 30 and the inner wall of the through hole 40, the screw is not easy to loosen and has a good anti-loosening effect.

[0028] The above embodiments are illustrative of the present invention and are not intended to limit the present invention. Any simple modifications to the present invention are within the protection scope of the present invention.

Claims

1. An Allen hex socket head screw characterized by: The screw head (1), screw rod (2) and expansion assembly are included. The screw head (1) is hexagonal and has an internal hexagonal turning groove (10) at the top. A screw rod (2) is fixed to the bottom of the screw. An expansion assembly is fitted on the outside of the screw rod (2). The expansion assembly consists of an upper fixing ring (31), a lower fixing ring (32) and an arc strip (30). The upper fixing ring (31) and the lower fixing ring (32) are both fitted on the outside of the screw rod (2). The upper fixing ring (31) is located above the lower fixing ring (32). Several outwardly protruding arc strips (30) are connected between the upper fixing ring (31) and the lower fixing ring (32). The upper fixing ring (31) is fixed to the screw head (1).

2. The hexalobular socket hexagon head screw of claim 1, wherein: The lower end face of the screw head (1) is provided with anti-slip texture.

3. The hexalobular socket hex-alien screw of claim 1, wherein: The lower part of the screw (2) is a guide platform (20), which is an inverted frustum cone shape, and the outer diameter of the guide platform (20) gradually decreases from top to bottom.

4. The hexalobular socket hex-alien screw of claim 1 wherein: The lower end of the screw head (1) is provided with an annular groove (11), and the upper fixing ring (31) is located in the annular groove (11).

5. The hexalobular socket hex-alien screw of claim 1 wherein: The inner diameter of the upper fixing ring (31) and the inner diameter of the lower fixing ring (32) are both greater than the outer diameter of the screw (2). The upper fixing ring (31) and the screw head (1) are welded together.

6. The hexalobular socket hex-alien screw of claim 1 wherein: The outer wall of the arc-shaped strip (30) has a frosted surface.

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