Anti-loose expansion sleeve and assembly thereof

Abstract

The utility model belongs to the field of expansion sleeves, and discloses an anti-loose expansion sleeve and an assembly thereof. The anti-loose expansion sleeve comprises an expansion sleeve body, outer teeth evenly distributed in the circumferential direction are arranged on the outer side of the expansion sleeve body, the expansion sleeve body is installed in the connecting end cover and detachably connected with the threaded fastener, and inner notches corresponding to the outer teeth are formed in an inner hole of the expansion sleeve body. Before the expansion sleeve is screwed into the threaded fastener, an inner hole of the expansion sleeve is an unthreaded hole, after the expansion sleeve is screwed into the threaded fastener, the inner hole of the expansion sleeve is extruded by the threaded fastener to generate self-tapping internal threads, the threaded fastener rotationally penetrates through the inner hole of the expansion sleeve, the inner hole is expanded towards the periphery by the threaded fastener, and the expansion sleeve and the threaded fastener are tightly combined to generate outward tension. The interference magnitude of the matched aperture of the expansion sleeve and the connecting end cover is further increased; the threaded fastener needs to be reversely rotated and separated from the expansion sleeve to overcome large friction force, the anti-loosening effect is far higher than that of traditional thread anti-loosening, and the anti-loosening performance is reliable.

Description

Technical Field

[0001] This utility model belongs to the field of expansion sleeve technology, and relates to an anti-loosening expansion sleeve and its components. Background Technology

[0002] Traditional M6 and smaller threaded fasteners have small thread sizes, resulting in lower tightening and breaking torques. For example, the tightening torque of an 8.8 grade M6 bolt commonly used in the automotive industry is only 10 Nm. With a torque of 12 N·m, especially when mating with screw holes on aluminum alloy substrates, the actual bearing capacity of the screw threads in the screw holes is even lower, and the tightening torque that can be withstood is limited. Particularly in situations where vibration and impact occur during component operation, loosening of the connection is highly likely. For some actuators, loosening of the connection will directly lead to the product losing its function. Currently, the main anti-loosening methods are applying thread-locking adhesive to the threaded portion, using elastic washers or other types of anti-loosening washers, so that after tightening, elastic deformation occurs, increasing the friction between the threaded connection pair and the surface of the washer and the threaded fastener, generating a resistance torque to prevent bolt loosening. However, this anti-loosening method is not ideal or even unsuitable for situations where the mating surface material is soft, the vibration and impact during operation are high, or the operating environment is unsuitable for using thread-locking adhesive. The main reason is that for softer mating surfaces, such as aluminum alloys, using elastic washers or other types of anti-loosening washers, after the bolt (nail) is tightened, the compressed washer will damage the mating surface, and ordinary flat washers will not provide anti-loosening protection. In environments with high vibration and impact, bolts (nail) coated with thread-locking adhesive will loosen after a period of use. The adhesive will usually turn into powder or form irregular sticky lumps, making it impossible to clean the adhesive off the bolt holes and threads, thus affecting reuse. Utility Model Content

[0003] The purpose of this utility model is to address the shortcomings of the prior art by providing an anti-loosening expansion sleeve and its components. The expansion sleeve has an outwardly protruding toothed ring structure. The outer ring of the expansion sleeve is provided with circumferentially evenly distributed external teeth, and the inner hole of the expansion sleeve is provided with an inner groove corresponding to the external teeth. The expansion sleeve is interference-fitted into the connecting end cover for preventing loosening of threaded fasteners.

[0004] This utility model is achieved by the following technical solution: an anti-loosening expansion sleeve includes: an expansion sleeve, the outer side of which is provided with circumferentially distributed external teeth, the external teeth and the expansion sleeve are an integral structure, the expansion sleeve is installed in the connecting end cover and is detachably connected to the threaded fastener, and the inner hole of the expansion sleeve is provided with an inner groove corresponding to the external teeth.

[0005] Furthermore, the inner holes of the expansion sleeve are chamfered at both ends.

[0006] Furthermore, before the expansion sleeve is detachably connected to the threaded fastener, its inner hole is a smooth hole.

[0007] Furthermore, in its uninstalled, natural state, the inner diameter of the expansion sleeve is smaller than the diameter of the threaded fastener.

[0008] Furthermore, in its uninstalled, natural state, the diameter of the outer teeth of the expansion sleeve is larger than the diameter of the mating hole on the connecting end cap.

[0009] Furthermore, the external teeth are at least three in number.

[0010] Furthermore, the expansion sleeve is made of plastic.

[0011] An anti-loosening expansion sleeve assembly includes: an expansion sleeve, a connecting end cap, and a threaded fastener; the expansion sleeve is fixedly installed inside the connecting end cap, the threaded fastener passes through the expansion sleeve from top to bottom and is detachably connected to the connecting housing, and the connecting end cap is installed on one side of the connecting housing.

[0012] Furthermore, the threaded fastener is interference-fitted with the inner hole of the expansion sleeve.

[0013] Furthermore, the expansion sleeve and the connecting end cap are interference-fitted.

[0014] Compared with the prior art, the present invention has the following beneficial technical effects:

[0015] This utility model discloses an anti-loosening expansion sleeve. The expansion sleeve is inserted into the mating hole of the connecting end cap by compression and undergoes plastic deformation, resulting in a tight fit between the expansion sleeve and the inner wall of the mating hole of the connecting end cap. A threaded fastener rotates through the inner hole of the expansion sleeve, and the inner hole of the expansion sleeve, which has an inner groove, is pushed outward by the threaded fastener. The expansion sleeve and the threaded fastener are tightly connected, generating outward tension, further increasing the interference fit between the expansion sleeve and the connecting end cap.

[0016] This utility model provides an anti-loosening expansion sleeve. The thickness of the expansion sleeve is the same as or slightly greater than the depth of the mating hole on the connecting end cover. During use, the upper and lower end faces of the expansion sleeve will be compressed and deformed in the axial direction. The upper and lower end faces of the expansion sleeve are tightly fitted with the contact surfaces of the connecting end cover and the connecting housing, respectively, so that end face friction will be generated between the expansion sleeve and the contact surfaces of the connecting end cover and the connecting housing.

[0017] This invention relates to an anti-loosening expansion sleeve. The expansion sleeve is made of plastic, and its coefficient of friction with metal is greater than that between metals, further improving the anti-loosening effect on threaded fasteners. For a threaded fastener to rotate out of the expansion sleeve in the opposite direction, it needs to overcome a significant frictional force. Therefore, its anti-loosening effect is far superior to that of traditional threads, and its anti-loosening performance is more reliable.

[0018] This utility model provides an anti-loosening sleeve that is more environmentally friendly and cleaner than applying thread-locking adhesive, and can be reused.

[0019] This utility model discloses an anti-loosening expansion sleeve. The connection between the thread on the threaded fastener and the expansion sleeve can generate a large frictional anti-loosening effect. When tightening, a small tightening torque can be used to achieve a good anti-loosening effect, effectively protecting the threaded fastener from damage during tightening and disassembly, and providing better protection for small-sized threaded fasteners.

[0020] This utility model provides an anti-loosening sleeve, which, compared with traditional thread anti-loosening technology, effectively solves the problem in situations where the mating surface material is relatively soft, the vibration and impact during operation are large, and the environment is not suitable for using locking adhesive through physical anti-loosening means. It can be used under various conditions such as high temperature, low temperature, vibration, through holes, and blind holes, and has wide applicability. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the structure of an anti-loosening expansion sleeve according to the present invention;

[0023] Figure 2 This is a schematic diagram of the structure in this utility model where the expansion sleeve and the threaded fastener are connected to generate a self-tapping thread;

[0024] Figure 3 This is a front view of an anti-loosening expansion sleeve according to the present invention;

[0025] Figure 4 for Figure 3 Sectional view at AA;

[0026] Figure 5 This is a top view of the expansion sleeve installed on the connecting end cover in an embodiment of the present invention;

[0027] Figure 6 This is a schematic diagram of the structure of the expansion sleeve installed in the countersunk hole at the end of the connecting end cover in this embodiment of the utility model;

[0028] Figure 7 This is a schematic diagram of the structure in which the expansion sleeve is installed in the through hole of the connecting end cover in an embodiment of this utility model.

[0029] Figure label:

[0030] 1-Expansion sleeve; 11-External tooth; 12-Inner groove; 13-Chamfered orifice; 2-Connecting end cap; 3-Threaded fastener; 4-Connecting housing. Detailed Implementation

[0031] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention 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 invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0032] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the utility model described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, such as a process, method, system, product, or apparatus comprising a series of steps or units, are not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0033] The present invention will now be described in further detail with reference to the accompanying drawings:

[0034] Example 1

[0035] This utility model provides an anti-loosening expansion sleeve, including an expansion sleeve 1. The outer side of the expansion sleeve 1 is provided with circumferentially distributed external teeth 11. The external teeth 11 and the expansion sleeve 1 are integral structures. The expansion sleeve 1 is installed in the connecting end cover 2 and is detachably connected to the threaded fastener 3. The inner hole of the expansion sleeve 1 is provided with an inner groove 12 corresponding to the external teeth 11.

[0036] Specifically, such as Figure 1 As for Figure 6 As shown, the outer side of the expansion sleeve 1 is provided with circumferentially distributed external teeth 11, with at least 3 external teeth 11. In this embodiment, the number of external teeth 11 is 6. An inner groove 12 is provided in the inner hole of the expansion sleeve 1. The external teeth 11 and the inner groove 12 are located at the same position in the circumferential direction. In other words, the external teeth 11 and the inner groove 12 correspond to each other in spatial position, as shown. Figure 3 As shown.

[0037] It should be noted that threaded fastener 3 is a bolt or screw.

[0038] In its uninstalled, natural state, the inner diameter of the expansion sleeve 1 is smaller than the diameter of the threaded fastener 3, and the diameter of the outer teeth 11 of the expansion sleeve 1 is larger than the mating hole diameter on the connecting end cap 2.

[0039] Before the expansion sleeve 1 is screwed into the threaded fastener 3, the inner hole is a smooth hole. After the expansion sleeve 1 is screwed into the threaded fastener 3, the inner hole of the expansion sleeve 1 will generate self-tapping threads due to the pressure of the threaded fastener 3.

[0040] The inner holes of the expansion sleeve 1 are provided with chamfered corners 13 at both ends, which serve as guides for the threaded fasteners 3 when they are screwed into the expansion sleeve 1, making assembly and connection easier.

[0041] The self-tapping internal thread and the external thread of the threaded fastener 3 are tightly engaged to form a strong and reliable connection, preventing the threaded fastener 3 from coming out.

[0042] Example 2

[0043] An anti-loosening expansion sleeve assembly includes: an expansion sleeve 1, a connecting end cap 2, and a threaded fastener 3; the expansion sleeve 1 is fixedly installed inside the connecting end cap 2, and the threaded fastener 3 passes through the expansion sleeve 1 from top to bottom and is detachably connected to the connecting housing 4 for anti-loosening purposes; the connecting end cap 2 is installed on one side of the connecting housing 4.

[0044] like Figure 5 As shown, the expansion sleeve 1 is installed inside the connecting end cover 2. Specifically, the expansion sleeve 1 is installed in the bolt through hole or the countersunk hole at the through hole end of the connecting end cover 2, such as... Figure 6 As shown, the expansion sleeve 1 is connected to the countersunk hole at the through hole end of the connecting end cap 2, as follows. Figure 7 As shown, the expansion sleeve 1 is connected to the connecting end cap 2 through a hole. The connecting end cap 2 and the connecting housing 4 are connected by threaded fasteners 3, and the expansion sleeve 1 is used to prevent the threaded fasteners 3 from loosening.

[0045] In its uninstalled, natural state, the diameter of the outer teeth 11 of the expansion sleeve 1 is larger than the mating hole diameter of the connecting end cover 2. This means that the expansion sleeve 1 needs to be squeezed into the mating hole diameter of the connecting end cover 2 during installation. The mating surfaces squeeze each other during installation, causing the outer teeth 11 of the expansion sleeve 1 to deform and fit tightly with the mating hole diameter on the connecting end cover 2, ensuring that the expansion sleeve 1 is difficult to come out of the mating hole diameter on the connecting end cover 2.

[0046] In the installed state, the outer teeth 11 of the expansion sleeve 1 are interference-fitted with the connecting end cover 2. During the installation process, the mating hole diameters of the expansion sleeve 1 and the connecting end cover 2 will deform to a certain extent, thereby achieving a tight fit.

[0047] In its uninstalled, natural state, the inner diameter of the expansion sleeve 1 is smaller than the diameter of the threaded fastener 3. When the threaded fastener 3 is screwed clockwise into the expansion sleeve 1, the inner diameter and inner groove 12 of the expansion sleeve 1 are pushed outwards by the threaded fastener 3, creating a self-tapping internal thread within the inner diameter of the expansion sleeve 1. Figure 2 As shown. The inner wall of the expansion sleeve 1 is interference-fitted with the threaded fastener 3, generating outward tension, which further increases the interference between the outer teeth 11 of the expansion sleeve 1 and the connecting end cap 2, making the fit between the expansion sleeve 1 and the connecting end cap 2 tighter.

[0048] Rotate the threaded fastener 3 clockwise. The threaded fastener 3 passes through the expansion sleeve 1 and the connecting end cover 2, and screws the threaded fastener 3 into the connecting housing 4. The connecting end cover 2 and the connecting housing 4 are assembled by the threaded fastener 3.

[0049] The thickness of the expansion sleeve 1 is the same as or slightly greater than the depth of the mating hole on the connecting end cover 2. When the threaded fastener 3 is tightened clockwise and a certain tightening torque is generated, the upper and lower end faces of the expansion sleeve 1 are compressed axially. The upper and lower end faces of the expansion sleeve 1 are tightly fitted with the contact surface, which will generate a large end face friction force.

[0050] For the threaded fastener 3 to rotate in the opposite direction and loosen or come out of the connecting end cap 2 and connecting housing 4, it is necessary to overcome the tightening torque generated when the threaded fastener 3 is screwed in, as well as the circumferential clamping friction of the expansion sleeve 1. In addition, it is also necessary to overcome the end face friction between the upper and lower end faces of the expansion sleeve 1 and the mating surface. The expansion sleeve 1 is made of plastic, and the coefficient of friction between plastic and metal is greater than the coefficient of friction between metals, which further improves the anti-rotation and anti-loosening effect of the threaded fastener 3.

[0051] In summary, for the threaded fastener 3 to loosen or come out by rotating in the opposite direction from the assembly hole, it is necessary to overcome a large frictional force. The anti-loosening effect produced by using the expansion sleeve 1 is far superior to that of traditional thread anti-loosening technology.

[0052] Compared with traditional thread anti-loosening technology, this method, which uses a physical anti-loosening method with an expansion sleeve, can effectively solve problems in situations where the mating surface material is relatively soft, the vibration and impact during operation are large, and the environment is not suitable for using locking adhesive. It can be used under various conditions such as high temperature, low temperature, vibration, through holes, and blind holes, making it widely applicable and reliable in anti-loosening performance.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and not to limit it. Although the utility model has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of this utility model. Any modifications or equivalent substitutions that do not depart from the spirit and scope of this utility model should be covered within the protection scope of the claims of this utility model.

Claims

1. A kind of anti-loose expansion sleeve, it is characterized by: Including expansion sleeve (1), the outer side of the expansion sleeve (1) is provided with the outer tooth (11) of equidistant distribution, the outer tooth (11) is integrated with expansion sleeve (1), the expansion sleeve (1) is installed in connecting end cover (2) and is detachably connected with threaded fastener (3), the inner hole of the expansion sleeve (1) is provided with the inner slot (12) corresponding with outer tooth (11).

2. The anti-loose expansion sleeve of claim 1, wherein: The inner hole of the expansion sleeve (1) is provided with hole chamfer (13) at both ends.

3. The anti-loose expansion sleeve of claim 1, wherein: Before the expansion sleeve (1) is detachably connected with threaded fastener (3), the inner hole is a light hole.

4. The anti-loose expansion sleeve of claim 3, wherein: In the natural state of uninstalled, the inner hole diameter of the expansion sleeve (1) is less than the diameter of threaded fastener (3).

5. The anti-loose expansion sleeve of claim 4, wherein: In the natural state of uninstalled, the outer tooth (11) diameter of the expansion sleeve (1) is greater than the matching hole diameter on the connecting end cover (2).

6. The anti-loose expansion sleeve of claim 1, wherein: The outer tooth (11) is at least 3.

7. The anti-loose expansion sleeve of claim 1, wherein: The expansion sleeve (1) is made of plastic.

8. A back-up assembly, comprising: Including: Expansion sleeve (1), connecting end cover (2), threaded fastener (3); The expansion sleeve (1) is fixedly installed in connecting end cover (2), the threaded fastener (3) is detachably connected with connecting shell (4) from top to bottom through expansion sleeve (1), and the connecting end cover (2) is installed on one side of the connecting shell (4).

9. The anti-loose expansion sleeve assembly of claim 8, wherein: In the installed state, the threaded fastener (3) is interference fit with the inner hole of the expansion sleeve (1).

10. The anti-loose expansion sleeve assembly of claim 9, wherein: In the installed state, the expansion sleeve (1) is interference fit with the connecting end cover (2).

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