20-degree transverse-vibration-resistant fastening connection pair

Abstract

The thread form of an external thread of a bolt is an isosceles trapezoid, a first inclined plane is cut on the surface of the bolt between two adjacent isosceles trapezoids, and the included angle alpha between the first inclined plane and the axial line of the bolt is 20 degrees; on the basis of an isosceles trapezoid, a second inclined plane is cut at a position corresponding to the first inclined plane, and the included angle beta between the second inclined plane and the center line of the nut is 20 degrees; the ratio of the bevel edge length L of the first inclined surface to the screw pitch D of the external thread of the bolt is 0.51-0.6; a first arc-shaped surface is cut at the thread root of the external thread of the bolt; and a second arc-shaped surface is cut at the thread root of the internal thread of the nut. According to the 20-degree transverse-vibration-resistant fastening connection pair, through the special thread tooth-shaped structure, larger radial occlusal force can be achieved with very light axial force, the transverse-vibration-resistant effect is good, looseness is not prone to occurring, and therefore a foundation is provided for light weight of the fastening connection pair for aerospace.

Description

Technical Field

[0001] The utility model belongs to the field of fasteners and relates to a fastening connection pair for aerospace, in particular to a 20° anti-lateral vibration fastening connection pair. Background Art

[0002] Fasteners are a type of mechanical parts that fasten two or more parts together. They are widely used and are called "the rice of industry". Aerospace fasteners refer specifically to fasteners used in aerospace, made of specific materials, with special properties or uses, and that can meet the special technical requirements of aerospace.

[0003] Weight reduction is an important indicator for the design of aerospace vehicles. The use of high specific strength materials can replace large-sized fasteners with lower specific strength. However, as the fasteners become lighter, the ability of nuts and bolts to resist lateral vibration when tightened will decrease. Aerospace vehicles will experience greater vibrations during operation, which may make the fasteners loose more easily. Utility Model Content

[0004] Based on the content in the background technology, the utility model provides a 20° anti-lateral vibration fastening connection pair, which has the characteristic of strong anti-lateral vibration ability.

[0005] A 20° anti-lateral vibration fastening connection pair, comprising a bolt and a nut, which are engaged with each other through an external thread and an internal thread, and characterized in that: the tooth profile of the external thread of the bolt is an isosceles trapezoid, and a first inclined surface is cut on the surface of the bolt between two adjacent isosceles trapezoids, and the angle α between the first inclined surface and the axial line of the bolt is 20°; the tooth profile of the internal thread of the nut is cut with a second inclined surface at a position corresponding to the first inclined surface on the basis of the isosceles trapezoid, and the angle β between the second inclined surface and the center line of the nut is 20°.

[0006] When the bolt and the nut are engaged with each other through the external thread and the internal thread, in addition to the screw locking between the thread tip and the thread root, the first bevel and the second bevel can also interfere with each other. The 20° bevel angle design can optimally balance the axial force and the clamping force, and can achieve a greater radial engagement force with a very light axial force. It has a good resistance to lateral vibration and is not prone to loosening.

[0007] Furthermore, the ratio of the hypotenuse length L of the first bevel to the pitch D of the external thread of the bolt is 0.51 to 0.6; the size of the pitch will affect the locking performance of the thread. When the bevel angle is determined to be 20°, the change in the hypotenuse length L of the first bevel will affect the friction between the internal and external threads through the change in the contact area (including the contact area between the two side edges of the thread profile). The determined ratio range of the hypotenuse length L to the pitch D can ensure that the locking ability of the fastening connection pair can be guaranteed while having good resistance to lateral vibration.

[0008] Furthermore, a first arcuate surface is cut at the thread root of the external thread of the bolt, and a second arcuate surface is cut at the thread root of the internal thread of the nut; when the internal and external threads are engaged, the thread tip plane of the external thread conflicts with the second arcuate surface of the internal thread, and the thread tip plane of the internal thread conflicts with the first arcuate surface of the external thread, which can reduce stress concentration caused by uneven force during vibration.

[0009] Preferably, the bolts and nuts are made of aluminum alloy or titanium alloy.

[0010] Through the above technical solution, the utility model at least includes the following beneficial effects:

[0011] The 20° anti-lateral vibration fastening connection pair of the present application, through the special thread tooth structure, can achieve a greater radial bite force with a very light axial force, has a good anti-lateral vibration effect, and is not prone to loosening, thereby providing a basis for the lightweight fastening connection pairs used in aerospace. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a schematic diagram of the overall structure of a 20° anti-lateral vibration fastening connection pair described in an embodiment of the present application;

[0013] Figure 2 for Figure 1 Sectional view at AA in the middle;

[0014] Figure 3 It is a partial cross-sectional view of the external thread of the bolt;

[0015] Figure 4 is a cross-sectional view of the nut;

[0016] Figure 5 for Figure 2 The enlarged view of point B in the figure; DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. These drawings are simplified schematic diagrams that only illustrate the basic structure of the present invention in a schematic manner, and therefore only show the structures related to the present invention.

[0018] In the description of this application, it should be understood that if there are terms such as "upper", "lower", "left", "right", "front", "rear", etc. indicating the orientation or positional relationship, they are based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship are only used for exemplary description and cannot be understood as limiting this patent; if there are terms such as "first", "second", etc., they are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second", etc. may explicitly or implicitly include one or more of the said features. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to the specific circumstances.

[0019] In the description of the utility model, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the utility model can be understood according to specific circumstances.

[0020] refer to Figures 1 to 5 A 20° anti-lateral vibration fastening connection pair comprises a bolt 1 and a nut 2, wherein the bolt 1 and the nut 2 are made of aluminum alloy or titanium alloy, and are engaged with each other through external threads and internal threads. The tooth profile of the external thread of the bolt 1 is an isosceles trapezoid, and a first bevel 101 is cut on the surface of the bolt 1 between two adjacent isosceles trapezoids, and the angle α between the first bevel 101 and the axial line of the bolt 1 is 20°; the tooth profile of the internal thread of the nut 2 is cut with a second bevel 201 at a position corresponding to the first bevel 101 on the basis of the isosceles trapezoid, and the angle β between the second bevel 201 and the center line of the nut 2 is 20°.

[0021] When the bolt 1 and the nut 2 are engaged with each other through the external thread and the internal thread, in addition to the screw-locking between the thread tip and the thread root, the first bevel 101 and the second bevel 201 can also interfere with each other. The 20° bevel angle design can optimally balance the axial force and the clamping force, and can achieve a greater radial engagement force with a very light axial force, has a good resistance to lateral vibration, and is not prone to loosening.

[0022] refer to Figure 5The ratio of the hypotenuse length L of the first bevel 101 to the pitch D of the external thread of the bolt 1 is 0.51-0.6; the size of the pitch will affect the locking performance of the thread. When the bevel angle is determined to be 20°, the change of the hypotenuse length L of the first bevel 101 will affect the friction between the internal and external threads through the change of the contact area (including the contact area between the two sides of the thread profile). The determined ratio range of the hypotenuse length L and the pitch D can ensure that the locking ability of the fastening connection pair can be guaranteed while having good resistance to lateral vibration.

[0023] refer to Figure 3 or Figure 5 The first arc surface 102 is cut at the thread root of the external thread of the bolt 1, referring to Figure 4 or Figure 5 A second arc surface 202 is cut at the thread root of the internal thread of the nut 2; when the internal and external threads are engaged, the thread tip plane of the external thread conflicts with the second arc surface 202 of the internal thread, and the thread tip plane of the internal thread conflicts with the first arc surface 102 of the external thread, which can reduce the stress concentration caused by uneven force during vibration.

[0024] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Based on the present invention and the above description, relevant personnel can make various changes and modifications without departing from the technical idea of ​​the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A 20° anti-lateral vibration fastening connection pair, comprising a bolt (1) and a nut (2), wherein the bolt (1) and the nut (2) are engaged with each other through an external thread and an internal thread, and characterized in that: The tooth profile of the external thread of the bolt (1) is an isosceles trapezoid, and a first bevel (101) is cut on the surface of the bolt (1) between two adjacent isosceles trapezoids, and the angle α between the first bevel (101) and the axial line of the bolt (1) is 20°; the tooth profile of the internal thread of the nut (2) is a second bevel (201) cut on the basis of the isosceles trapezoid at a position corresponding to the first bevel (101), and the angle β between the second bevel (201) and the center line of the nut (2) is 20°.

2. A 20° anti-lateral vibration fastening connection pair according to claim 1, characterized in that: The ratio of the length L of the hypotenuse of the first inclined surface (101) to the pitch D of the external thread of the bolt (1) is 0.51 to 0.

6.

3. A 20° anti-lateral vibration fastening connection pair according to claim 1 or 2, characterized in that: A first arcuate surface (102) is cut at the thread root of the external thread of the bolt (1), and a second arcuate surface (202) is cut at the thread root of the internal thread of the nut (2).

4. A 20° anti-lateral vibration fastening connection pair according to claim 1 or 2, characterized in that: The bolt (1) and nut (2) are made of aluminum alloy or titanium alloy.

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