Fastener

Abstract

The utility model provides a fastener which comprises a tightening piece, an anti-loosening piece and a self-locking piece, the tightening piece is constructed to be combined with a matched screw to fasten a fastened piece and comprises a main body part, the main body part is constructed to be a regular prism, and the side surface of the main body part is suitable for being matched with a wrench device to drive the tightening piece to rotate; the anti-loosening piece is constructed to be annular, the anti-loosening piece and the main body part are coaxially arranged, and a first joint part is arranged on the peripheral surface of the anti-loosening piece; the self-locking piece is constructed to be annular and is arranged on the tightening piece and the anti-loosening piece in a sleeving mode, and a second joint part is arranged on the inner circumferential face of the self-locking piece; wherein the second joint part is configured to be respectively matched with the edge of the main body part and the first joint part so as to lock the tightening piece and the anti-loosening piece and prevent the tightening piece from loosening.

Description

Technical Field

[0001] At least one embodiment of the present utility model relates to a fastener, and more specifically, to a fastener that can prevent further loosening of a tightened member. Background Art

[0002] Fasteners are widely used in various industries that require connection and fixation, such as the automotive, construction, agricultural, and manufacturing industries. In large construction machinery and engineering vehicles, due to the harsh working environment and heavy loads, fasteners are often subjected to multi-directional vibrations and load impacts, which can cause nuts to loosen easily. This not only weakens the function of the fasteners but may also lead to their complete failure, thereby posing serious safety risks.

[0003] Currently, the common fastener anti-loosening methods mainly include two types: one is to increase the friction force at the contact surface of the fastener to achieve short-term anti-loosening effects, such as using auxiliary components like spring washers and external-toothed lock washers to provide additional frictional resistance when the fastener is vibrating, thereby effectively maintaining the fixation of the fastener. However, over time and due to the influence of vibrations, the friction force will gradually decrease, resulting in a gradual weakening of the anti-loosening effect. The other is to achieve anti-loosening effects by changing the physical structure of the thread or using mechanical locking means, such as using locking adhesives, lock nuts, and stop washers. These methods can prevent relative rotation of the threads to a certain extent, thereby achieving the purpose of anti-loosening. However, in a long-term heavy-load and vibration environment, the thread deformation or mechanical locking structure may experience fatigue damage, thus reducing the anti-loosening effect.

[0004] Therefore, in view of the deficiencies of these existing technologies, there is an urgent need for a more effective and reliable fastener anti-loosening solution to ensure the safe operation of mechanical equipment and extend its service life. Summary of the Utility Model

[0005] In view of this, an embodiment of the present utility model provides a fastener that can, after a tightened member and an anti-loosening member are fastened to a fastened member, use a self-locking member to lock the tightened member and the anti-loosening member, hinder the loosening of the tightened member, and improve the anti-loosening performance of the fastener.

[0006] One aspect of an embodiment of the present utility model provides a fastener, including: a tightening member, a loosening prevention member, and a self-locking member. The tightening member is configured to be combined with a mating screw rod to fasten a fastened object, and includes a main body portion. The main body portion is configured as a regular prism, and the side surface of the main body portion is adapted to cooperate with a wrench device to drive the tightening member to rotate; the loosening prevention member is configured as an annular shape, and the loosening prevention member is coaxially arranged with the main body portion. A first engaging portion is provided on the outer circumferential surface of the loosening prevention member; the self-locking member is configured as an annular shape and is sleeved on the tightening member and the loosening prevention member. A second engaging portion is provided on the inner circumferential surface of the self-locking member; wherein, the second engaging portion is configured to cooperate with the edge of the main body portion and the first engaging portion respectively to lock the tightening member and the loosening prevention member and prevent the tightening member from loosening.

[0007] According to an embodiment of the present utility model, the first engaging portion is configured as an external plum blossom tooth extending along the axial direction of the fastener, and the number of teeth of the external plum blossom tooth is an integer multiple of the number of edges of the main body portion; the second engaging portion is configured as an internal plum blossom tooth that cooperates with the external plum blossom tooth; wherein, the diameter of the circumscribed circle of the bottom surface of the main body portion is the same as the diameter of the tooth top circle of the external plum blossom tooth, so that the second engaging portion cooperates with the edge of the main body portion and the first engaging portion respectively.

[0008] According to an embodiment of the present utility model, the internal plum blossom tooth is larger than the external plum blossom tooth to facilitate the self-locking member to be sleeved on the loosening prevention member.

[0009] According to an embodiment of the present utility model, the thickness of the self-locking member is greater than the thickness of the loosening prevention member, so that the self-locking member cooperates with the edge of the main body portion and the first engaging portion simultaneously.

[0010] According to an embodiment of the present utility model, it further includes a stop member, which is installed on the main body portion and is adapted to block the self-locking member from moving away from the fastened object towards the main body portion.

[0011] According to an embodiment of the present utility model, the stop member includes a retaining ring, which is installed in a plurality of external grooves on the main body portion, and the plurality of external grooves are arranged on the edges of the main body portion in the circumferential direction of the main body portion.

[0012] According to an embodiment of the present utility model, a plurality of anti-loosening strips are arranged at intervals on the end surface of the loosening prevention member opposite to the tightening member, and each anti-loosening strip is configured to extend along the radial direction of the loosening prevention member and is adapted to be in close contact with the surface of the fastened object under the pre-tightening force of the tightening member.

[0013] According to an embodiment of the present utility model, it is characterized in that the tightening member further includes a first positioning portion axially protruding from an end face of the main body portion facing the anti-loosening member; a second positioning portion is provided on an end face of the anti-loosening member facing the tightening member, and the second positioning portion is configured as a recessed portion that cooperates with the first positioning portion to increase the friction force between the tightening member and the anti-loosening member after the tightening member is pre-tightened, thereby restricting the rotation of the tightening member relative to the anti-loosening member.

[0014] According to an embodiment of the present utility model, the first positioning portion is configured as an annular tapered boss that tapers axially from the end face, and the second positioning portion is configured as an annular tapered groove that cooperates with the tapered boss.

[0015] According to an embodiment of the present utility model, the tightening member is a nut, and the nut is in threaded engagement with the mating screw.

[0016] According to an embodiment of the present utility model, the tightening member and the anti-loosening member are coaxially arranged. During the pre-tightening process of the tightening member rotating along the mating screw, the anti-loosening member is squeezed, increasing the friction force with the fastened member and improving the anti-loosening effect. Among them, the main body portion of the tightening member is a regular prism, which is convenient for the wrench device to drive the rotation. At the same time, the anti-loosening member is an annular structure, and a first engaging portion is provided on the outer peripheral surface. The self-locking member is also annular, and a second engaging portion is provided on the inner peripheral surface. After the tightening member is fastened, the self-locking member is sleeved on the tightening member and the anti-loosening member, so that the second engaging portion cooperates with the first engaging portion and the edges of the main body portion to lock the tightening member and the anti-loosening member, achieving the effect of hindering the loosening of the tightening member and improving the stability and reliability of the fastener. Especially in an environment where vibration and load are long-term, the fastener can be kept from loosening easily. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Through the following description of the embodiments of the present utility model with reference to the drawings, the above and other objects, features, and advantages of the present utility model will become clearer. In the drawings:

[0018] Figure 1 A perspective view of a first perspective of a fastener according to an embodiment of the present utility model is schematically shown;

[0019] Figure 2 Schematically shown Figure 1 A perspective view of a second perspective of the fastener shown;

[0020] Figure 3 Schematically shown Figure 1 An exploded view of a first perspective of the fastener shown;

[0021] Figure 4 Schematically shown Figure 1 An exploded view of a second perspective of the fastener shown;

[0022] Figure 5 Schematically shows a perspective view of the first angle of the anti-loosening member according to an embodiment of the present invention;

[0023] Figure 6 Schematically shows Figure 5 a perspective view of the second angle of the anti-loosening member shown;

[0024] Figure 7 Schematically shows a perspective view of the first angle of the self-locking member according to an embodiment of the present invention;

[0025] Figure 8 Schematically shows a perspective view of the first angle of the tightening member according to an embodiment of the present invention;

[0026] Figure 9 Schematically shows Figure 8 a perspective view of the second angle of the tightening member shown.

[0027] Description of reference numerals

[0028] 1. Tightening member;

[0029] 11. Main body part;

[0030] 111. Outer groove;

[0031] 12. First positioning part;

[0032] 2. Anti-loosening member;

[0033] 21. First engaging part;

[0034] 22. Second positioning part;

[0035] 23. Anti-loosening strip;

[0036] 3. Self-locking member;

[0037] 31. Second engaging part; and

[0038] 4. Stopper. Detailed implementation manners

[0039] To make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to specific embodiments and the accompanying drawings.

[0040] The terms used herein are only for describing specific embodiments and are not intended to limit the present invention. The terms "including", "comprising", etc. used herein indicate the presence of the described features, steps, operations and / or components, but do not exclude the presence or addition of one or more other features, steps, operations or components.

[0041] All terms used herein, including technical and scientific terms, have the meanings commonly understood by those of ordinary skill in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification, and should not be interpreted in an idealized or overly rigid manner.

[0042] In cases where expressions such as "at least one of A, B, and C, etc." are used, generally, it should be interpreted according to the meaning commonly understood by those of ordinary skill in the art. For example, "a system having at least one of A, B, and C" should include, but not be limited to, a system having only A, only B, only C, having A and B, having A and C, having B and C, and / or having A, B, and C, etc. In cases where expressions such as "at least one of A, B, or C, etc." are used, generally, it should be interpreted according to the meaning commonly understood by those of ordinary skill in the art. For example, "a system having at least one of A, B, or C" should include, but not be limited to, a system having only A, only B, only C, having A and B, having A and C, having B and C, and / or having A, B, and C, etc.

[0043] It should also be noted that the directional terms mentioned in the embodiments, such as "up", "down", "front", "rear", "left", "right", etc., are only for reference to the drawings and are not used to limit the protection scope of the present invention. Throughout the drawings, the same elements are represented by the same or similar reference numerals. When it may cause confusion in the understanding of the present invention, conventional structures or configurations will be omitted.

[0044] Figure 1 A perspective view of a first perspective of a fastener according to an embodiment of the present invention is schematically shown; Figure 2 Schematically shown Figure 1 A perspective view of a second perspective of the fastener shown; Figure 3 Schematically shown Figure 1 An exploded view of a first perspective of the fastener shown; Figure 4 Schematically shown Figure 1 An exploded view of a second perspective of the fastener shown.

[0045] On the one hand, an embodiment of the present invention provides a fastener, such as Figures 1 to 4As shown in the figure, it includes a tightening member 1, a loosening prevention member 2, and a self-locking member 3. The tightening member 1 is configured to be combined with a mating screw to fasten a fastened member, and includes a main body portion 11 which is configured as a regular prism. The side surface of the main body portion 11 is adapted to cooperate with a wrench device to drive the tightening member 1 to rotate. The loosening prevention member 2 is configured as an annular shape, coaxially arranged with the main body portion 11, and a first engaging portion 21 is provided on the outer peripheral surface of the loosening prevention member 2. The self-locking member 3 is configured as an annular shape, sleeved on the tightening member 1 and the loosening prevention member 2, and a second engaging portion 31 is provided on the inner peripheral surface of the self-locking member 3. Among them, the second engaging portion 31 is configured to cooperate with the edges of the main body portion 11 and the first engaging portion 21 respectively to lock the tightening member 1 and the loosening prevention member 2 and prevent the tightening member 1 from loosening.

[0046] According to the above setting method, the tightening member 1 and the loosening prevention member 2 are coaxially arranged. During the pre-tightening process of the tightening member 1 rotating along the mating screw, the loosening prevention member 2 is squeezed, increasing the frictional force with the fastened member and improving the loosening prevention effect. Among them, the main body portion 11 of the tightening member 1 is a regular prism, which is convenient for the wrench device to drive the rotation. At the same time, the loosening prevention member 2 is an annular structure, and a first engaging portion 21 is provided on the outer peripheral surface. The self-locking member 3 is also an annular shape, and a second engaging portion 31 is provided on the inner peripheral surface. After the tightening member 1 is fastened, the self-locking member 3 is sleeved on the tightening member 1 and the loosening prevention member 2, so that the second engaging portion 31 cooperates with the first engaging portion 21 and the edges of the main body portion 11 to lock the tightening member 1 and the loosening prevention member 2, achieving the effect of preventing the tightening member 1 from loosening, improving the stability and reliability of the fastener. Especially in an environment where it is long-term subjected to vibration and load, the fastener can be kept from loosening easily.

[0047] In a schematic embodiment, a through hole penetrating in the axial direction of the fastener is provided at the center of the main body portion 11, and a thread cooperating with the mating screw is provided on the through hole.

[0048] Figure 5 Schematically shows a perspective view of the first angle of the loosening prevention member of the embodiment of the present utility model; Figure 6 Schematically shows Figure 5 A perspective view of the second angle of the loosening prevention member shown in the figure: Figure 7 Schematically shows a perspective view of the first angle of the self-locking member of the embodiment of the present utility model.

[0049] In a schematic embodiment, as Figures 5 to 7 shown, the first engaging portion 21 is configured as an external plum blossom tooth extending along the axial direction of the fastener, and the number of teeth of the external plum blossom tooth is an integer multiple of the number of edges of the main body portion 11; the second engaging portion 31 is configured as an internal plum blossom tooth cooperating with the external plum blossom tooth; among them, the diameter of the circumscribed circle of the bottom surface of the main body portion 11 is the same as the diameter of the tooth tip circle of the external plum blossom tooth, so that the second engaging portion 31 cooperates with the edges of the main body portion 11 and the first engaging portion 21 respectively.

[0050] According to the above setting method, the first engaging portion 21 of the anti-loosening member 2 and the second engaging portion 31 of the self-locking member 3 are respectively set as an external plum blossom tooth and an internal plum blossom tooth structure with the same number of teeth. Through the cooperation of teeth, the anti-loosening member 2 and the self-locking member 3 are kept relatively fixed to each other. Further, the number of teeth of the external plum blossom tooth and the internal plum blossom tooth is an integer multiple of the number of edges of the main body portion 11, and the diameter of the circumscribed circle of the bottom surface of the main body portion 11 is the same as the diameter of the tooth tip circle of the external plum blossom tooth. Without affecting the cooperation between the main body portion 11 and the wrench device, the second engaging portion 31 can simultaneously cooperate with the edges of the main body portion 11 and the first engaging portion 21, and it is convenient for the self-locking member 3 to be installed and disassembled axially. This solution realizes the locking of the tightening member 1 and the anti-loosening member 2 in the circumferential direction of the fastener through precise tooth profile matching and dimension matching, effectively prevents the loosening of the fastener, greatly improves the stability and reliability of the fastener under vibration and load, and ensures the durability and safety of the connection.

[0051] In a schematic embodiment, as Figure 2 shown, the internal plum blossom tooth is larger than the external plum blossom tooth to facilitate the self-locking member 3 to be sleeved on the anti-loosening member 2.

[0052] According to the above setting method, during the installation process, the self-locking member 3 can be smoothly sleeved on the anti-loosening member 2 and the tightening member 1, which simplifies the installation process and improves work efficiency.

[0053] In an alternative embodiment, the outer surface of the first engaging portion 21 is configured as a regular prismatic shape surrounded by the same rectangles, and the number of edges of the first engaging portion 21 is an integer multiple of the number of edges of the main body portion 11; the inner surface of the second engaging portion 31 is configured as a regular prismatic shape that cooperates with the first engaging portion 21 and is surrounded by the same rectangles; wherein the diameter of the circumscribed circle of the bottom surface of the main body portion 11 is the same as the diameter of the circumscribed circle of the outer surface of the first engaging portion 21, so that the second engaging portion 31 cooperates with the edges of the main body portion 11 and the first engaging portion 21 respectively.

[0054] In an alternative embodiment, the second engaging portion 31 is slightly larger than the second engaging portion 21.

[0055] In a schematic embodiment, the thickness of the self-locking member 3 is greater than the thickness of the anti-loosening member 2, so that the self-locking member 3 cooperates with the edges of the main body portion 11 and the first engaging portion 21 simultaneously.

[0056] According to the above setting method, by setting the thicknesses of the self-locking member 3 and the anti-loosening member 2, during the assembly process, the second engaging portion 31 of the self-locking member 3 can penetrate between the edges of the main body portion 11 and the first engaging portion 21 of the anti-loosening member 2 to form a firm locking fit. The anti-loosening performance of the fastener is improved, and the connection stability under vibration and load is ensured.

[0057] Furthermore, the thickness setting of the self-locking member 3 also simplifies the installation process. During the installation of the self-locking member 3, only by abutting the self-locking member 3 against the fastener to be fastened can the locking fit between the tightening member 1 and the anti-loosening member 2 be achieved, reducing the operation time caused by the adjustment that requires ensuring that the second mating portion 31 must be in contact with the edge of the main body portion 11 and the first engaging portion 21 simultaneously, and improving the work efficiency.

[0058] In a schematic embodiment, as Figures 1 to 4 shown, it further includes a stop member 4, which is installed on the main body portion 11 and is adapted to prevent the self-locking member 3 from moving away from the fastener to be fastened towards the main body portion 11.

[0059] According to the above setting method, based on the thickness setting of the self-locking member 3, installing the stop member 4 at an appropriate position on the main body portion 11 can fix the self-locking member 3 between the stop member 4 and the fastener to be fastened, preventing the self-locking member 3 from moving away from the fastener to be fastened and falling off.

[0060] Figure 8 Schematically shows a perspective view of the first angle of the tightening member of the embodiment of the present invention; Figure 9 Schematically shows Figure 8 the perspective view of the second angle of the tightening member shown.

[0061] In a schematic embodiment, as Figures 1 to 4 、 Figures 8 to 9 shown, the stop member 4 includes a retaining ring, which is installed in a plurality of outer grooves 111 on the main body portion 11, and the plurality of outer grooves 111 are arranged on the edge of the main body portion 11 in the circumferential direction of the main body portion 11.

[0062] According to the above setting method, using the retaining ring as the stop member 4 and installing it in a plurality of outer grooves 111 on the circumference of the main body portion 11 effectively ensures the stability of the self-locking member 3 during the tightening operation, prevents the displacement and falling off of the self-locking member 3 relative to the fastener to be fastened, and thus improves the firmness and safety of the overall structure.

[0063] In a schematic embodiment, as Figure 6 shown, a plurality of anti-loosening strips 23 are spaced apart on the end face of the anti-loosening member 2 opposite to the tightening member 1, and each anti-loosening strip 23 is configured to extend radially along the anti-loosening member 2 and is adapted to be in close contact with the surface of the fastener to be fastened under the pre-tightening force of the tightening member 1.

[0064] According to the above setting method, the anti-loosening strips 23 are pressed into the main body of the fastener to be fastened under the pre-tightening force of the tightening member 1 to form a close contact, so that the anti-loosening member 2 is kept fixed, significantly enhancing the frictional resistance between the anti-loosening member 2 and the fastener to be fastened, and effectively preventing the loosening of the fastener under vibration or load.

[0065] In an alternative embodiment, ratchet teeth are provided on the end face of the anti-loosening member 2 opposite to the tightening member 1, and are configured to be radially arranged. Among them, the inclination direction of the tooth crest or tooth valley of the ratchet teeth is opposite to the pre-tightening rotation direction of the tightening member 1, so that the frictional force between the anti-loosening member 2 and the fastened member is greater than the frictional force between the tightening member 1 and the loosening member 2, so that when the tightening member 1 loosens relative to the mating screw, the anti-loosening member 2 remains stationary relative to the fastened member and the mating screw.

[0066] In a schematic embodiment, as Figure 5 and Figure 9 shown, the tightening member 1 further includes a first positioning portion 12 that axially protrudes from the end face of the main body portion 11 facing the anti-loosening member 2; a second positioning portion 22 is provided on the end face of the anti-loosening member 2 facing the tightening member 1, and the second positioning portion 22 is configured as a recess that cooperates with the first positioning portion 12, so as to increase the frictional force between the tightening member 1 and the anti-loosening member 2 after the tightening member 1 is pre-tightened, and limit the rotation of the tightening member 1 relative to the anti-loosening member 2.

[0067] According to the above setting method, by respectively providing the axially protruding first positioning portion 12 and the cooperating concave second positioning portion 22 on the end faces of the tightening member 1 and the anti-loosening member 2 facing each other, the positioning function can be realized during the pre-tightening process, and the tightening member 1 and the anti-loosening member 2 are always kept in a coaxial state, so that the pre-tightening force applied by the tightening member 1 to the anti-loosening member 2 after fastening is balanced, the stability of the fastener is increased, and at the same time, the frictional force between the tightening member 1 and the anti-loosening member 2 is increased, and the rotation of the tightening member 1 relative to the anti-loosening member 2 is restricted from loosening.

[0068] In a schematic embodiment, as Figure 5 and convex 9 shown, the first positioning portion 12 is configured as an annular tapered boss that tapers axially from the end face, and the second positioning portion 22 is configured as an annular tapered groove that cooperates with the tapered boss.

[0069] According to the above setting method, the first positioning portion 12 is designed as an annular tapered boss, and the second positioning portion 22 is designed as an annular tapered groove that cooperates with it. When the tightening member 1 is pre-tightened, the cooperation between the tapered boss and the tapered groove not only increases the frictional force of the contact surface, but also due to the characteristics of the tapered structure, as the tightening member 1 is further tightened, the cooperation between the two becomes closer, thus more effectively restricting the relative rotation of the tightening member 1 relative to the anti-loosening member 2. The anti-loosening performance is significantly improved, so that the pre-tightened state of the tightening member 1 and the anti-loosening member 2 can be maintained even under the influence of vibration or torque.

[0070] In a schematic embodiment, the tightening member 1 is a nut, and the nut is in threaded engagement with the mating screw.

[0071] In a schematic embodiment, the tightening member 1 can be a square nut or a hexagonal nut.

[0072] The fastener according to the embodiment of the present utility model can be applied to working machinery, for example, used as a connecting member for crawler shoes and chassis parts in engineering vehicles. During the fastening process, first, the anti-loosening member 2 is sleeved on the mating screw rod that has been pre-passed through the preset hole on the fastener to be fastened. The end face of the anti-loosening member 2 provided with the anti-loosening strip 23 or ratchet teeth faces the fastener to be fastened, which can effectively prevent the fastener from loosening under vibration or dynamic load. Next, the tightening member 1 is threadedly connected to the mating screw rod, and the first positioning portion 12 and the second positioning portion 22 are arranged to face each other, and a wrench device is used to drive the tightening member to rotate. During the process of pre-tightening rotation, the tightening member 1 continuously applies a pre-tightening force to the anti-loosening member, increasing the friction force between the first positioning portion 12 and the second positioning portion 22, and between the anti-loosening member 2 and the fastener to be fastened, thereby ensuring the firmness of the connection. When the fastening is completed, the self-locking member 3 is axially sleeved on the tightening member 1 and the anti-loosening member 2 from the fastener to lock the tightening member 1 and the anti-loosening member 2, further preventing the fastener from loosening. Finally, the stop member 4 is installed on the main body portion 11 to prevent the self-locking member 3 from falling off, and the fastening is completed. During the disassembly process, the stop member 4 is preferably disassembled first, and then the wrench device is used to reversely rotate the tightening member to make it loosen and fall off. The design of this fastener ensures that the connection remains firm and reliable under heavy loads and vibrations in working machinery, and at the same time is convenient for maintenance and replacement, effectively reducing loosening caused by vibration or dynamic load, and improving the safety and working efficiency of engineering vehicles.

[0073] The embodiments of the present utility model have been described above. However, these embodiments are only for illustrative purposes and not for limiting the scope of the present utility model. Although the embodiments have been described separately above, this does not mean that the measures in each embodiment cannot be used in combination advantageously. The scope of the present utility model is defined by the appended claims and their equivalents. Without departing from the scope of the present utility model, those skilled in the art can make various substitutions and modifications, and these substitutions and modifications should all fall within the scope of the present utility model.

Claims

1. A fastener, characterized in that, Comprising: A tightening member (1), configured to be combined with a mating screw to fasten a fastened member, including: A main body portion (11), configured as a regular prism, and side surfaces of the main body portion (11) are adapted to cooperate with a wrench device to drive the tightening member (1) to rotate; A lock prevention member (2), configured as an annular shape, the lock prevention member (2) is coaxially arranged with the main body portion (11), and a first engagement portion (21) is provided on an outer peripheral surface of the lock prevention member (2); and A self-locking member (3), configured as an annular shape, sleeved on the tightening member (1) and the lock prevention member (2), and a second engagement portion (31) is provided on an inner peripheral surface of the self-locking member (3); Wherein, the second engagement portion (31) is configured to cooperate with edges of the main body portion (11) and the first engagement portion (21) respectively to lock the tightening member (1) and the lock prevention member (2), and prevent the tightening member (1) from loosening.

2. The fastener according to claim 1, wherein, The first engagement portion (21) is configured as an external plum blossom tooth extending along an axis of the fastened member, and the number of teeth of the external plum blossom tooth is an integer multiple of the number of edges of the main body portion (11); The second engagement portion (31) is configured as an internal plum blossom tooth that cooperates with the external plum blossom tooth; Wherein, an outer circumferential circle of a bottom surface of the main body portion (11) has the same diameter as a tooth top circle of the external plum blossom tooth, so that the second engagement portion (31) cooperates with edges of the main body portion (11) and the first engagement portion (21) respectively.

3. The fastener according to claim 2, wherein The internal plum blossom tooth is larger than the external plum blossom tooth to facilitate the self-locking member (3) to be sleeved on the lock prevention member (2).

4. The fastener according to claim 1, wherein The thickness of the self-locking member (3) is greater than the thickness of the lock prevention member (2), so that the self-locking member (3) cooperates with edges of the main body portion (11) and the first engagement portion (21) simultaneously.

5. The fastener according to claim 4, characterized in that, It further includes a stop member (4), installed on the main body portion (11), and adapted to block the self-locking member (3) from moving away from the fastened member towards the main body portion (11).

6. The fastener according to claim 5, wherein The stop member (4) includes a snap ring, installed in a plurality of outer grooves (111) on the main body portion (11), and the plurality of outer grooves (111) are arranged on edges of the main body portion (11) in a circumferential direction of the main body portion (11).

7. The fastener according to claim 1, wherein On an end surface of the lock prevention member (2) opposite to the tightening member (1), a plurality of anti-loosening strips (23) are spaced apart, and each anti-loosening strip (23) is configured to extend along a radius of the lock prevention member (2), and is adapted to be in close contact with a surface of the fastened member under a pre-tightening force of the tightening member (1).

8. The fastened member according to claim 1, wherein The tightening member (1) further includes a first positioning portion (12), axially protruding from an end surface of the main body portion (11) facing the lock prevention member (2); On an end surface of the lock prevention member (2) facing the tightening member (1), a second positioning portion (22) is provided, and the second positioning portion (22) is configured as a recess that cooperates with the first positioning portion (12) to increase a frictional force between the tightening member (1) and the lock prevention member (2) after the tightening member (1) is pre-tightened, and limit rotation of the tightening member (1) relative to the lock prevention member (2).

9. The fastener according to claim 8, characterized in that, The first positioning portion (12) is configured as an annular tapered boss whose end face tapers in the axial direction, and the second positioning portion (22) is configured as an annular tapered groove that cooperates with the tapered boss.

10. The fastener according to any one of claims 1-9, characterized in that, The tightening member (1) is a nut, and the nut is in threaded engagement with the mating screw.

Images