Stable self-locking connection fastening structure

Abstract

The stable self-locking connecting and fastening structure comprises a groove bolt and a bulge nut, the groove bolt comprises a polished rod part, an external thread part is arranged at the first end of the polished rod part, and a plurality of inner grooves are formed in the external thread part; the bump nut comprises a nut body, an internal thread part is arranged on the inner wall of the nut body, the first end of the nut body is a driving end, a plurality of bump outer protrusions are arranged on the outer wall of the driving end, and the number of the bump outer protrusions is smaller than or equal to that of the inner grooves. When the bulge nut is connected with the groove bolt, the bulge outer bulge can be plastically deformed under a set torque to be extruded and filled into the inner groove and the outer thread part so as to form a mechanical self-locking structure; the second end of the nut body is a bearing end, and the cross section of the bearing end is polygonal. The connecting structure is compact in structure and convenient to mount, and can meet the functional requirements of controllable torque, stable self-locking and no generation of redundancy after mounting and the performance requirements of long service life, high reliability and the like of the connecting structure.

Description

Technical Field

[0001] The present invention relates to the technical field of aerospace mechanical connection, and particularly relates to a connection and fastening structure with stable self-locking. Background Art

[0002] Today's advanced aerospace vehicles rely on advanced mechanical connection technologies, and must adopt advanced high-performance connectors and connection and fastening system technologies, etc., to ensure performance requirements such as stable self-locking and high reliability of the structure. Traditional aerospace fasteners or fastening systems often use methods such as necking extrusion to increase the friction between bolts and nuts for anti-loosening to achieve the purpose of self-locking. However, when this self-locking method is used in harsh environments such as high temperature and high pressure, and severe vibration, there are certain variables in the stability of the locking performance and the reliability of the connection and fastening. In addition, with the continuous upgrading of advanced aerospace vehicles, the structural design is becoming more and more compact, and higher requirements are also put forward for the installation methods of fasteners. Especially in some narrow spaces, it is required that no debris is allowed to be generated after installation to prevent the debris from being difficult to clean up and causing flight safety hazards. However, some existing fasteners or fastening systems (Hi-Lok bolts - nuts) will generate debris after installation, causing problems such as difficult cleaning of fragments and triggering safety hazards.

[0003] Therefore, based on the experience and practice of the inventor in the relevant industry for many years, a connection and fastening structure with stable self-locking is proposed to overcome the defects of the prior art. Summary of the Invention

[0004] The purpose of the present invention is to provide a connection and fastening structure with stable self-locking. The structure of the present invention is compact and easy to install, and can achieve the functional requirements of controllable torque, stable self-locking, no debris generation after installation, and performance requirements such as high life and high reliability of the connection structure.

[0005] The purpose of the present invention is achieved as follows: A connection and fastening structure with stable self-locking includes a grooved bolt and a bulged nut. The grooved bolt includes a smooth rod portion, and an external thread portion is provided at the first end of the smooth rod portion. A plurality of internal grooves are circumferentially and spacedly arranged on the external thread portion; the bulged nut includes a nut body, and an internal thread portion capable of being threadedly connected with the external thread portion is provided on the inner wall of the nut body. The first end of the nut body is a driving end, and a plurality of bulged external protrusions are circumferentially and spacedly arranged on the outer wall of the driving end. The number of the bulged external protrusions is less than or equal to the number of the internal grooves; when the bulged nut is connected with the grooved bolt, the bulged external protrusions can be plastically deformed and extruded into the internal grooves and the external thread portion under a set torque to form a mechanical self-locking structure; the second end of the nut body is a bearing end, and the cross-section of the bearing end is polygonally arranged.

[0006] In a preferred embodiment of the present invention, the length direction of the outer protrusion of each boss is parallel to the axial direction of the nut body, and the cross-section of the outer protrusion of each boss is circular arc-shaped, square-shaped, elliptical-shaped, or polygonal-shaped. The cross-section of the inner groove is matched with the cross-section of the outer protrusion of the boss.

[0007] In a preferred embodiment of the present invention, the driving end of the nut body and the outer protrusions of each boss are made of TA18 alloy.

[0008] In a preferred embodiment of the present invention, the second end of the external thread portion is the finishing end, and the finishing end adopts a short thread structure. The axial length of the short thread structure is less than or equal to 1.5 times the pitch.

[0009] In a preferred embodiment of the present invention, a wrenching portion is provided at the first end of the external thread portion, and a nail head portion with an increasing diameter is provided at the second end of the smooth rod portion. When the boss nut is connected to the grooved bolt, the bearing end of the nut body is connected to one side of the external thread portion close to the nail head portion, and the driving end of the nut body is connected to one side of the external thread portion close to the wrenching portion.

[0010] In a preferred embodiment of the present invention, the wrenching portion includes a wrenching groove, and the wrenching groove extends inward from the end surface of the second end of the external thread portion.

[0011] In a preferred embodiment of the present invention, the cross-section of the wrenching groove is pentagonal flower-shaped.

[0012] In a preferred embodiment of the present invention, the nail head portion is a countersunk head structure or a flat round head structure.

[0013] In a preferred embodiment of the present invention, the countersunk head angle of the countersunk head structure is 90°, 100°, or 130°.

[0014] In a preferred embodiment of the present invention, the surfaces of the grooved bolt and the boss nut are coated with a coating unit.

[0015] As described above, the stable self-locking connection and fastening structure of the present invention has the following beneficial effects:

[0016] In the present invention, the bulge of the bulged nut fills into the inner groove and the external thread part after extrusion deformation, so that the groove bolt and the bulged nut are more tightly engaged, forming a stable mechanical self-locking structure, and the locking torque is controllable, without causing damage or destruction to the connected parts. At the same time, no redundant matter is generated after the whole installation process. Compared with the traditional anti-loosening form relying on friction, the anti-loosening performance of this structure is more reliable and stable; the bearing end of the nut body is designed as a polygonal structure, which is convenient for nut disassembly, saves materials and reduces weight; the structure of the present invention is compact and easy to install, and can meet the functional requirements of controllable torque, stable self-locking, no redundant matter generated after installation, as well as the performance requirements such as high life and high reliability of the connection structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The following drawings are only intended to illustrate and explain the present invention schematically, and do not limit the scope of the present invention.

[0018] Wherein:

[0019] Figure 1 : is a schematic view of the stable self-locking connection and fastening structure of the present invention.

[0020] Figure 2 : is a front view of the groove bolt with a countersunk head structure at the nail head of the present invention.

[0021] Figure 3 : is Figure 2 View A in

[0022] Figure 4 : is Figure 2 Enlarged view at B in

[0023] Figure 5 : is Figure 2 Cross-sectional view taken along line C-C in

[0024] Figure 6 : is a schematic cross-sectional view of the wrenching groove of the groove bolt of the present invention.

[0025] Figure 7 : is a front view of the groove bolt with a flat round head structure at the nail head of the present invention.

[0026] Figure 8 : is a side view of the bulged nut of the present invention.

[0027] Figure 9 : is Figure 8 Cross-sectional view taken along line D-D in

[0028] Figure 10 : is a schematic view of the external bulge of the bulged nut of the present invention.

[0029] Figure 11: Schematic diagram of the bearing end of the bulged nut of the present invention.

[0030] In the figure:

[0031] 1. Grooved bolt; 11. Smooth rod part; 12. External thread part; 13. Inner groove; 14. End part; 15. Wrenching part; 16. Nail head part;

[0032] 2. Bulged nut; 21. Nut body; 22. Driving end; 23. Bulged outer protrusion; 24. Bearing end. Detailed implementation manners

[0033] For a clearer understanding of the technical features, objectives, and effects of the present invention, the detailed implementation manners of the present invention will now be described with reference to the accompanying drawings.

[0034] The detailed implementation manners of the present invention described herein are only for the purpose of explaining the present invention and should not be construed in any way as a limitation of the present invention. Under the teaching of the present invention, those skilled in the art can conceive any possible variations based on the present invention, and these should all be regarded as belonging to the scope of the present invention. It should be noted that when an element is referred to as being "disposed on" another element, it can be directly on the other element or there can also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "mounted", "connected", and "coupled" should be understood in a broad sense. For example, they can be mechanical connections or electrical connections, or they can be the internal communication of two elements. They can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances. The terms "vertical", "horizontal", "upper", "lower", "left", "right", and similar expressions used herein are only for the purpose of illustration and do not represent the only implementation manner.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific implementation manners and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0036] As Figures 1 to 11 shown, the present invention provides a stable self-locking connection and fastening structure, including a grooved bolt 1 and a bulged nut 2;

[0037] The groove bolt 1 comprises a polished rod portion 11, a first end of which is provided with an external threaded portion 12, and a plurality of internal grooves 13 are arranged on the external threaded portion 12 at intervals along the circumferential direction; the internal grooves 13 can be formed by extrusion or milling.

[0038] The bulge nut 2 comprises a nut body 21, an inner wall of the nut body 21 is provided with an internal threaded portion that can be threadedly connected (threadedly screwed) with the external threaded portion 12, a first end of the nut body 21 is a driving end 22, a plurality of bulge external protrusions 23 are arranged on the outer wall of the driving end 22 at intervals in the circumferential direction, and the number of the bulge external protrusions 23 is less than or equal to the number of the internal grooves 13;

[0039] When the bulge nut 2 is connected to the groove bolt 1, the bulge outer protrusion 23 can be plastically deformed under a set torque and squeezed into the inner groove 13 and the outer threaded portion 12 to form a mechanical self-locking structure;

[0040] The second end of the nut body 21 is a load-bearing end 24, and the cross section of the load-bearing end 24 is a polygon. After installation, the load-bearing end fits with the structural member to play the role of bearing and clamping. Figure 11 As shown, the load-bearing end 24 (bottom structure) is designed as a hexagonal head structure, and can also be designed as other polygonal structures such as quadrilaterals, octagons, dodecagons, etc., which can facilitate the removal of the nut and achieve the effect of saving materials and reducing weight.

[0041] The inner groove 13 of the groove bolt 1 and the bulged outer protrusion 23 of the bulged nut 2 are both multiple, and the number of the inner groove 13 can be more than the bulged outer protrusion 23 (generally 1 to 2 more) to facilitate extrusion forming; and the bulged outer protrusion 23 has good plasticity. After reaching a certain torque, the bulged outer protrusion 23 will easily undergo plastic deformation and be randomly squeezed into the nearest inner groove 13 and the outer threaded part 12 (thread), without the need for one-to-one matching.

[0042] In the present invention, the bulged outer protrusion 23 of the bulged nut 2 is filled into the inner groove 13 and the outer threaded portion 12 after being extruded and deformed, the groove bolt 1 and the bulged nut 2 are more tightly engaged to form a stable mechanical self-locking structure, and the locking torque is controllable, and will not cause damage or destruction to the connected parts. At the same time, no excess material is generated after the entire installation process is completed. Compared with the traditional anti-loosening form relying on friction, the anti-loosening performance of this structure is more reliable and stable; the load-bearing end 24 of the nut body 21 is designed to be a polygonal structure, which is convenient for nut disassembly, while saving materials and reducing weight; the present invention has a compact structure and is easy to install, and can achieve the functional requirements of controllable torque, stable self-locking, and no excess material after installation, as well as the performance requirements of high life and high reliability of the connection structure.

[0043] Further, if Figure 8 , Figure 9As shown, the length direction of each outer bulge 23 of the bulge is parallel to the axial direction of the nut body 21, that is, each outer bulge 23 of the bulge extends a certain length along the direction parallel to the central axis towards the bearing end (the bottom of the nut), forming a bulge solid structure.

[0044] As Figure 5 , Figure 10 shown, the cross-section of each outer bulge 23 of the bulge is arranged in the form of an arc, a square, an ellipse, a polygon, etc., and the cross-section of the inner groove 13 is arranged to match the cross-section of the outer bulge 23 of the bulge.

[0045] As Figure 10 shown, in a specific embodiment of the present invention, 3 to 8 outer bulges 23 of the bulge are arranged at intervals along the circumferential direction on the outer wall of the driving end 22. 3 to 8 inner grooves 13 are arranged at intervals along the circumferential direction on the external thread portion 12 of the grooved bolt 1. The outer bulge 23 of the bulge and the inner groove 13 are designed correspondingly. Through the dimensional design of the structure of the matching outer bulge 23 of the bulge and the inner groove 13, it is ensured that after the installation is completed, the outer bulge 23 of the bulge nut 2 can be smoothly squeezed and filled into the inner groove 13 and the external thread portion 12 of the grooved bolt 1.

[0046] Furthermore, the driving end 22 of the nut body and each outer bulge 23 of the bulge are made of TA18 alloy, which has good plasticity and can undergo large deformation, meeting the requirement of plastic deformation extrusion into the inner groove 13 and the external thread portion 12 under a certain torque to achieve connection self-locking.

[0047] Furthermore, as Figure 1 , Figure 2 , Figure 4 , Figure 7 shown, the second end of the external thread portion 12 is the finishing end 14, and the finishing end 14 adopts a short thread structure, and the axial length of the short thread structure is less than or equal to 1.5 times the pitch. The finishing end 14 and the outer wall of the optical rod portion 11 are connected by a transition arc.

[0048] Furthermore, as Figure 2 shown, a wrenching portion 15 is arranged at the first end of the external thread portion 12, and a nail head portion 16 with an increasing diameter is arranged at the second end of the optical rod portion 11; the nail head portion 16 and the optical rod portion 11 are designed to be connected by an arc transition.

[0049] When the bulge nut 2 is connected to the grooved bolt 1, the bearing end 24 of the nut body 21 is connected to the side of the external thread portion 12 close to the nail head portion 16, and the driving end 22 of the nut body 21 is connected to the side of the external thread portion 12 close to the wrenching portion 15.

[0050] Furthermore, as Figure 2 shown, the wrenching portion 15 includes a wrenching groove, and the wrenching groove extends inward from the end face of the second end of the external thread portion 12.

[0051] As Figure 2 , Figure 3 , Figure 6 shown, in a specific embodiment of the present invention, the cross-section of the wrenching groove is pentagonal flower-shaped. The pentagonal petals are arc structures, and there is an arc transition connection between the pentagonal petals and the bottom hole, and the arc radius refers to the design standard.

[0052] The wrenching groove of the grooved bolt adopts a pentagonal flower-shaped groove structure, which can reduce stress concentration, make the force more uniform, and thus can bear a greater wrenching torque.

[0053] Furthermore, the structure of the nail head 16 can be designed in various forms, such as a countersunk head structure or a flat round head structure. In a specific embodiment of the present invention, the countersunk head angle of the countersunk head structure is 90°, 100° or 130°.

[0054] Furthermore, the surfaces of the grooved bolt 1 and the bulged nut 2 are coated with a coating unit. The coating can be selected by itself, such as an aluminum coating, a molybdenum disulfide coating, etc.

[0055] When installing the stable self-locking connection and fastening structure of the present invention, the installation tools mainly include a rotary drive sleeve and a five-flower groove wrenching head (prior art). The drive sleeve is a rotating part, and the five-flower groove wrenching head is a fixed part. Before installing the bolt and the nut, the fastening object has been clamped between the nail head 16 and the bearing end 24 of the bulged nut 2. During installation, the drive sleeve is sleeved on the drive end (top) of the bulged nut 2 to drive the bulged outer protrusion 23 of the bulged nut 2 and drive the bulged nut 2 to rotate together. The five-flower groove wrenching head is inserted into the wrenching groove at the bottom of the grooved bolt 1 to fix the grooved bolt 1 to prevent it from rotating together with the bulged nut 2 during the installation process. When installed to the predetermined number of turns, the torque increases (to the set torque), and the bulged outer protrusion 23 of the bulged nut 2 will deform and gradually be squeezed and filled into the inner groove 13 and the external thread part 12 of the grooved bolt 1. At this time, the bulged outer protrusion 23 at the drive end of the bulged nut 2 disappears, forming a smooth cylindrical surface, and the installation is completed.

[0056] As described above, the stable self-locking connection and fastening structure of the present invention has the following beneficial effects:

[0057] In the present invention, the bulges on the outer bulge of the bulged nut are filled into the inner groove and the external thread part after extrusion deformation, so that the groove bolt and the bulged nut are more tightly engaged, forming a stable mechanical self-locking structure, and the locking torque is controllable, without causing damage or destruction to the connected parts. At the same time, there is no redundant material generated after the entire installation process. Compared with the traditional anti-loosening form relying on friction, the anti-loosening performance of this structure is more reliable and stable; the bearing end of the nut body is designed as a polygonal structure, which is convenient for nut disassembly, saves materials and reduces weight; the structure of the present invention is compact and easy to install, and can meet the functional requirements of controllable torque, stable self-locking, no redundant material generated after installation, as well as the performance requirements of high life and high reliability of the connection structure.

[0058] The above are only the schematic specific embodiments of the present invention, and are not intended to limit the scope of the present invention. Any equivalent changes and modifications made by those skilled in the art without departing from the concept and principle of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A stable self-locking connection and fastening structure, Characterized in that, It includes a grooved bolt and a bulged nut. The grooved bolt includes a smooth rod portion. An external thread portion is provided at the first end of the smooth rod portion, and a plurality of internal grooves are circumferentially and spacedly arranged on the external thread portion; the bulged nut includes a nut body, and an internal thread portion capable of being threadedly connected to the external thread portion is provided on the inner wall of the nut body. The first end of the nut body is a driving end, and a plurality of bulged external protrusions are circumferentially and spacedly arranged on the outer wall of the driving end. The number of the bulged external protrusions is less than or equal to the number of the internal grooves; when the bulged nut is connected to the grooved bolt, the bulged external protrusions can be plastically deformed under a set torque and be extruded and filled into the internal grooves and the external thread portion to form a mechanical self-locking structure; the second end of the nut body is a bearing end, and the cross-section of the bearing end is polygonally arranged.

2. The stable self-locking connection and fastening structure according to claim 1, Characterized in that, The length directions of the bulged external protrusions are parallel to the axial direction of the nut body. The cross-sections of the bulged external protrusions are circular arc-shaped, square-shaped, elliptical-shaped, or polygonally arranged, and the cross-section of the internal groove is matched with the cross-section of the bulged external protrusion.

3. The stable self-locking connection and fastening structure according to claim 1, Characterized in that, The driving end of the nut body and the bulged external protrusions are made of TA18 alloy.

4. The stable self-locking connection and fastening structure according to claim 1, Characterized in that, The second end of the external thread portion is a finishing end, and the finishing end adopts a short thread structure, and the axial length of the short thread structure is less than or equal to 1.5 times the pitch.

5. The stable self-locking connection and fastening structure according to claim 4, Characterized in that, A wrenching portion is provided at the first end of the external thread portion, and a nail head portion with an increasing diameter is provided at the second end of the smooth rod portion; when the bulged nut is connected to the grooved bolt, the bearing end of the nut body is connected to the side of the external thread portion close to the nail head portion, and the driving end of the nut body is connected to the side of the external thread portion close to the wrenching portion.

6. The stable self-locking connection and fastening structure according to claim 5, Characterized in that, The wrenching portion includes a wrenching groove, and the wrenching groove extends inward from the end surface of the second end of the external thread portion.

7. The stable self-locking connection and fastening structure according to claim 6, Characterized in that, The cross-section of the wrenching groove is pentagonal flower-shaped.

8. The stable self-locking connection and fastening structure according to claim 5, Characterized in that, The nail head portion is a countersunk head structure or a flat round head structure.

9. The stable self-locking connection and fastening structure according to claim 8, Characterized in that, The countersunk head angle of the countersunk head structure is 90°, 100°, or 130°.

10. The stable self-locking connection and fastening structure according to claim 1, Characterized in that, The surfaces of the grooved bolt and the bulged nut are coated with a coating unit.

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