CN110439906B

CN110439906B - Effective anti-loosening clamping type self-locking nut

Info

Publication number: CN110439906B
Application number: CN201910798321.3A
Authority: CN
Inventors: 张亚晓; 李春玲; 王博洋; 樊恒岩
Original assignee: Aerospace Precision Products Co Ltd
Current assignee: Aerospace Precision Products Co Ltd
Priority date: 2019-08-27
Filing date: 2019-08-27
Publication date: 2021-03-26
Anticipated expiration: 2039-08-27
Also published as: CN110439906A

Abstract

The invention provides an effective anti-loosening clamping type self-locking nut which comprises a main body provided with an internal thread, wherein a plurality of clamping hooks are uniformly distributed on the tail part of the main body along the circumference, a groove of each clamping hook can accommodate at least one thread tooth of a bolt, the maximum rotary inner diameter of the groove is larger than the major diameter of the bolt thread, two sides of the groove are respectively formed by enclosing an inner transition structure and an inner reducing structure, the inner transition structure is used for transition between the internal thread of the nut and the groove, the outer surface of each clamping hook is provided with an outer transition structure and an outer reducing structure, and the inner reducing structure and the outer reducing structure jointly enclose a hook angle which can penetrate into the bolt thread gap. The invention has simple structure and convenient processing, and does not need any matching design for the bolt.

Description

Effective anti-loosening clamping type self-locking nut

Technical Field

The invention relates to the technical field of fasteners, in particular to an effective anti-loosening clamping type self-locking nut.

Background

The fastener is a mechanical part which is used for fastening connection and has wide application, and various fasteners can be seen on various machines, equipment, vehicles, ships, railways, bridges, buildings, structures, tools, instruments, meters and the like. The purpose of the fastener is to fasten, and once the fastener loosens and falls off due to vibration, impact and the like, the device, machinery and the like can lose the functionality and the disassembly of the device, the machinery and the like, and even the personal safety is endangered. More than 80% of accidents of current mechanical equipment are caused by loosening of fasteners.

The nut is a part which is screwed together with a bolt or a screw rod in a fastener and plays a role in fastening, and the nut is particularly easy to loosen and fall off in a high-frequency vibration environment, particularly in an aerospace mechanical structure. Through continuous research and development, a series of products and methods for improving the tightness of the nut are produced, products with loosening and vibration resisting effects such as a self-locking nut and a high-locking nut are formed, and the loosening risk still exists. In the existing nut structure design, the methods for improving the anti-loosening performance mainly comprise the following steps: (1) the anti-loosening device comprises a bolt, a nut, a locking ring, a spring, a reverse screw and a reverse screw, wherein the bolt is arranged on the nut, the nut is clamped or limited by the aid of the special structure, and the special structure is designed on the bolt. In the methods of the existing nut structure design, at least two parts are generally needed to complete the method, such as the methods (1) - (3), the structure design is complex or the reliability is not high, the parts are not easy to process, the lightweight requirement of aerospace is not easy to realize, and the parts are also easy to be poorly matched to increase the risk of secondary falling; in addition, as described in the method (4), although the number of parts can be reduced, the bolt needs to be separately designed, and the bolt and the nut need to be processed in a matching manner, so that the application requirements can be met, the processing cost is high, the process is complicated, and the requirement of light weight is not favorable. Therefore, a nut structure product which is simple in structure, easy to machine and good in anti-loosening effect is urgently needed.

Disclosure of Invention

The invention aims to provide an effective anti-loosening clamping type self-locking nut which is simple in structure and convenient to process and does not need any matching design on a bolt.

The invention discloses an effective anti-loosening clamping type self-locking nut which comprises a main body provided with an internal thread, wherein a plurality of clamping hooks are uniformly distributed on the tail of the main body along the circumference, grooves of the clamping hooks can accommodate at least one thread tooth of a bolt, the maximum rotary inner diameter of each groove is larger than the major diameter of the thread of the bolt, two sides of each groove are respectively formed by enclosing an inner transition structure and an inner reducing structure, the inner transition structure is used for transition between the internal thread of the nut and the groove, the outer surfaces of the clamping hooks are provided with outer transition structures and outer reducing structures, and the inner reducing structures and the outer reducing structures jointly enclose hook corners which can penetrate into the thread clearance of the bolt.

The self-locking nut provided by the invention is of an integrally formed structure.

The relation between the distance H between the end part of the inner reducing structure extending into the groove and the end part of the outer reducing structure extending to the outside in the direction vertical to the axis and the thread pitch d of the bolt thread is more than 0 and less than or equal to 0.5d, preferably more than or equal to 0.25d and less than or equal to 0.5 d.

Furthermore, a spacing groove is formed between the adjacent hooks, the side wall enclosing the spacing groove is the side wall of the hook, and the distance between the side walls on the two sides of the hook increases from inside to outside.

The inner diameter-changing structure and the outer diameter-changing structure are provided with end transition structures, and transition surfaces are also arranged between the side walls and the bottom surfaces of the spacing grooves.

The transition surface, the inner transition structure, the outer transition structure and the end transition structure are respectively independent cambered surfaces, single-section planes or multi-section planes.

The head of the main body is also provided with a wrenching structure.

The self-locking nut provided by the invention has the advantages of simple structure, convenience in installation, no need of arranging redundant sub-parts and complicated bolt matched with the self-locking nut, excellent anti-loosening and anti-seismic effects and capability of meeting the light weight requirement of aerospace.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

fig. 1 is a schematic structural view of the tail direction of the present invention.

Fig. 2-3 are schematic cross-sectional structures of the present invention.

Fig. 4 is a schematic diagram of the force action of the present invention.

Fig. 5 is a schematic view of the assembled structure of the present invention.

Fig. 6-7 are enlarged partial views of different snap-on conditions of the present invention after installation.

Detailed Description

For a better understanding of the present invention, reference is made to the following detailed description taken in conjunction with the accompanying drawings.

The invention provides an effective anti-loose clip-type self-locking nut, which comprises a main body 5 provided with internal threads 4 as shown in figures 1-3, a plurality of hooks 3 are evenly distributed on the tail part of the main body 5 along the circumference, at least one thread tooth of a bolt can be accommodated in a groove 32 of each hook 3, the maximum rotary inner diameter of the groove 32 is larger than the major diameter of the bolt thread, two sides of the groove 32 are respectively enclosed by an inner transition structure 31 and an inner reducing structure 33, the inner transition structure 31 is used for transition between the nut internal thread 4 and the groove 32, the outer surface of the hook 3 is provided with an outer transition structure 36 and an outer reducing structure 34, and the inner reducing structure 33 and the outer reducing structure 34 jointly enclose a hook angle which can go deep into a thread gap of the bolt (namely, the minimum rotary inner diameter of the inner reducing structure 33 and/or the outer reducing structure 34 is between the small diameter and the large diameter of the thread of the bolt).

The bolt provided by the invention is a bolt capable of being matched with the self-locking nut (figure 5). The self-locking nut provided by the invention is of an integrally formed structure, the clamping hook 3 can play a larger clamping force through integral forming, in the nut installation process, the clamping hook 3 climbs along the bolt thread, the clamping hooks 3 are basically the same in size and are positioned at the same circumferential position, a thread path is not provided, the clamping hook 3 can randomly stop at any position of the bolt thread structure (figures 6-7) during locking, and a certain acting force is borne at the stopping position. The force is applied primarily through the inner diameter changing structure 33 and/or the outer diameter changing structure 34. As shown in fig. 4, during the tightening process, the inner diameter-changing structure 33 is a main force-bearing surface, the acting force F1 can be decomposed into a force F12 perpendicular to the axial direction and a force F11 parallel to the axial direction and opposite to the advancing direction, the hook 3 is forced to expand outwards by the F12 to generate elastic deformation, so that the nut can be screwed in smoothly, and meanwhile, the elastic deformation provides a reverse clamping force opposite to the force F1, which plays a role in preventing looseness during the loosening process; in the loosening process, the outer reducing structure 34 is a main stress surface, acting force F2 can be decomposed into inward force F21 perpendicular to the axial direction and inward force F22 parallel to the axial direction and opposite to the loosening direction, F21 also provides inward clamping force perpendicular to the axial direction, and F22 prevents the nut from moving towards the loosening direction, so that the reliability of the locking performance of the nut is guaranteed. The invention has the double effects of preventing the loosening direction from moving and clamping inwards under the stress action of the two stress surfaces.

In order to optimize the stress effect and improve the anti-loosening reliability and the structural stability of the clamping hook 3, the invention optimally designs the structural design of the clamping hook 3. The relation between the included angle alpha between the outer reducing structure 34 and the direction vertical to the axis, the included angle beta between the inner reducing structure 33 and the direction vertical to the axis, and the included angle gamma between the bolt thread and the direction vertical to the axis is more than 0 and less than beta and less than gamma, the relation between the distance H between the end part of the inner reducing structure 33 extending towards the groove 32 and the end part of the outer reducing structure 34 extending towards the outside in the direction vertical to the axis and the thread pitch d of the bolt thread is more than 0 and less than H and less than 0.5d, preferably more than 0.25d and less than H and less than 0.5 d. After the structure is optimized, the stress intensity of the clamping hook 3 is increased, more reliable anti-loosening acting force can be provided, the reliable locking effect is still maintained under severe vibration, and the integrated effective clamping with a simple structure is realized.

Further, a spacing groove 2 is formed between adjacent hooks 3, the side wall enclosing the spacing groove 2 is the side wall 37 of the hook 3, and the distance between the side walls 37 at two sides of the hook 3 increases from inside to outside. The inner diameter-changing structure 33 and the outer diameter-changing structure 34 are provided with end transition structures 35, and transition surfaces are also arranged between the side walls 37 and the bottom surfaces of the spacing grooves 2. The transition surface, the inner transition structure 31, the outer transition structure 36 and the end transition structure 35 can reduce stress concentration, improve structural stability and prolong service life, and the transition structures can be cambered surfaces, single-section planes or multi-section planes.

The head of the main body 5 is also provided with a pulling and screwing structure 1, so that the nut can be conveniently clamped by adopting a tool, the structure is not limited, and the pulling and screwing structure can be any conventional pulling and screwing structure, such as a hexagonal head, a quadrangular head, a pulling and screwing groove and the like.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims

1. The utility model provides an effective locking card formula self-locking nut that takes off, is including main part (5) that is equipped with internal thread (4), main part (5) afterbody is followed the circumference equipartition and is had a plurality of pothooks (3), at least one thread tooth of bolt can be held in slot (32) of pothook (3), the biggest gyration internal diameter of slot (32) is greater than the big footpath of bolt thread, the both sides of slot (32) are enclosed by interior transition structure (31) and interior reducing structure (33) respectively and are closed and form, and interior transition structure (31) are used for the transition between nut internal thread (4) and slot (32), pothook (3) surface has outer transition structure (36) and outer reducing structure (34), interior reducing structure (33) and outer reducing structure (34) enclose jointly and synthesize the hook angle that can go deep into bolt thread clearance;

the relation between the included angle alpha between the outer reducing structure (34) and the direction vertical to the axis, the included angle beta between the inner reducing structure (33) and the direction vertical to the axis, and the included angle gamma between the thread teeth of the bolt and the direction vertical to the axis is more than 0 and less than alpha and less than beta and less than gamma;

the relation between the distance H between the end part of the inner reducing structure (33) extending into the groove (32) and the end part of the outer reducing structure (34) extending to the outside in the direction vertical to the axis and the thread pitch d of the bolt thread is more than 0 and less than or equal to 0.5 d;

a spacing groove (2) is formed between the adjacent hooks (3), the side wall enclosing the spacing groove (2) is the side wall (37) of the hook (3), and the distance between the side walls (37) at the two sides of the hook (3) increases from inside to outside.

2. The effective anti-loosening captive self-locking nut of claim 1, wherein the self-locking nut is of an integrally formed construction.

3. The effective anti-loosening clip-type self-locking nut as claimed in claim 1, wherein the distance H between the end of the inner diameter-changing structure (33) extending into the groove (32) and the end of the outer diameter-changing structure (34) extending to the outside in the direction perpendicular to the axis and the pitch d of the bolt thread are in a relationship of 0.25d to 0.5 d.

4. The effective anti-loosening self-locking nut as claimed in claim 1, wherein the inner diameter-changing structure (33) and the outer diameter-changing structure (34) are provided with end transition structures (35), and transition surfaces are also provided between the side walls (37) and the groove bottom surfaces of the spacing grooves (2).

5. The effective anti-loosening snap-type self-locking nut according to claim 4, wherein the transition surface, the inner transition structure (31), the outer transition structure (36), and the end transition structure (35) are each independently an arc surface, a single plane, or a multi-plane.

6. The effective anti-loosening self-locking nut as claimed in claim 1, wherein a wrenching structure (1) is further provided at the head of the main body (5).