An aircraft radome connection structure

Abstract

The application relates to the technical field of fairings and thermal protection of hypersonic aircraft, in particular to an aircraft antenna cover connecting structure. The aircraft antenna cover connecting structure comprises an antenna cover, nuts and heat insulation screws corresponding to the nuts. The antenna cover comprises a connecting end for connecting with a rear cabin section. An inner wall of the connecting end is circumferentially spaced apart with at least three nut holes. A bolt hole in communication with the nut holes is further arranged in the connecting end. The nuts corresponding to the nut holes are arranged in the nut holes. The heat insulation screws corresponding to the nuts are arranged to pass through connecting holes on the rear cabin section and bolt holes on the connecting end to connect with the nuts, so as to connect the rear cabin section and the connecting end. The application can solve the problem that the adhesives in the prior art have the risk of falling off even if the temperature of the adhesives is improved.

Description

Technical Field

[0001] This invention relates to the field of hypersonic vehicle radome and thermal protection technology, specifically to a vehicle antenna radome connection structure. Background Technology

[0002] During hypersonic vehicle flight, the radome primarily protects the seeker head, ensuring it operates at a suitable temperature to meet effective electrical performance requirements. Located at the nose of the vehicle, the radome experiences the greatest aerodynamic forces and heating, necessitating that it simultaneously meet static and thermal strength requirements while maintaining effective electrical performance. Composite quartz or silicon nitride ceramics are widely used as radome materials due to their excellent high-temperature resistance, high-temperature strength, and superior dielectric properties. However, load transfer between the ceramic material and the aft metal hull material presents a design challenge and is one of the main causes of radome failure.

[0003] Typically, radomes are connected to the rear fuselage by bonding low-expansion alloys to form a complete structure, thereby transferring the head load. The bonding process is complex, highly random, and prone to uncontrollable debonding, limiting the uniformity of bonding. Furthermore, the adhesives are difficult to use in environments exceeding 200°C, posing significant challenges to the use of radomes in hypersonic weapons.

[0004] Currently, existing technologies employ methods such as changing the type of adhesive or improving the adhesive to increase its operating temperature, but these methods still carry the risk of detachment. Summary of the Invention

[0005] In view of the defects existing in the prior art, the purpose of the present invention is to provide an aircraft radome connection structure that can solve the problem that the existing technology, which uses adhesives or improves the operating temperature by modifying the adhesives, still has the risk of falling off.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] This invention provides an aircraft radome connection structure, comprising:

[0008] The radome includes a connection end for connection to a rear section, wherein the inner wall of the connection end is provided with at least three nut holes spaced apart circumferentially for placing nuts, and the connection end is also provided with bolt holes communicating with the nut holes and extending to the end face of the connection end for passing through heat insulation screws.

[0009] A nut corresponding to each of the aforementioned nut holes, the nut being disposed within the nut hole, and the size of the nut matching the width and depth of the nut hole;

[0010] A heat-insulating screw corresponding to the nut is used to connect the rear compartment and the connecting end by passing through the connecting hole on the rear compartment and the bolt hole on the connecting end.

[0011] In some alternative designs, a heat shield is also provided inside the radome.

[0012] In some alternative solutions, the heat shield comprises two layers of shielding together.

[0013] In some alternative designs, both layers of the cover are cup-shaped with their openings facing the connecting end, and the sidewalls of the two layers of the cover are in close contact with each other, with their bottoms spaced apart.

[0014] In some alternative solutions, both layers of the cover are made of aerogel.

[0015] In some alternative solutions, a heat insulation pad is provided on the end face of the connection end.

[0016] In some alternative designs, the heat insulation pad has a protrusion on the side near the connection end for engaging with the inside of the connection end.

[0017] In some alternative solutions, the outer diameter of the heat insulation pad is smaller than the outer diameter of the connecting end.

[0018] In some alternative designs, the nut is fitted with a protective sleeve, which is made of copper.

[0019] In some alternative embodiments, the heat-insulating screw includes a screw and a heat-insulating ring, the heat-insulating ring being fitted onto the screw.

[0020] Compared with the prior art, the advantages of this invention are as follows: At least three nut holes are circumferentially spaced on the inner wall of the radome's connecting end, and bolt holes connected to these nut holes are provided on the connecting end. Nuts are placed in the corresponding nut holes, and the connecting holes passing through the rear section and the bolt holes on the connecting end are connected to the nuts, thus connecting the rear section and the connecting end. Using heat-insulating screws and nuts to connect the rear section and the radome improves the connection strength between them and allows it to withstand higher temperatures. It can withstand larger alternating loads and avoids the risks of uncontrollable radome debonding and high-temperature carbonization debonding of the adhesive layer in existing adhesive-type radomes, while also exhibiting long-term high-temperature resistance and reliable connection strength. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the aircraft radome connection structure in an embodiment of the present invention;

[0023] Figure 2 This is a schematic diagram of the connection between the radome and the rear section in an embodiment of the present invention.

[0024] In the diagram: 1. Antenna radome; 11. Connecting end; 2. Heat insulation screw; 3. Nut; 4. Rear section; 5. Heat insulation cover; 6. Heat insulation pad; 61. Protrusion; 7. Sheath. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0026] The embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0027] Figure 1 This is a schematic diagram of the aircraft radome connection structure in an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure at the connection between the radome and the rear section in an embodiment of the present invention, as shown below. Figure 1 and Figure 2 As shown, the present invention provides an aircraft radome connection structure, including: an radome 1, a nut 3, and a heat-insulating screw 2 corresponding to the nut 3. The radome 1 includes a connecting end 11 for connecting to a rear section 4. The inner wall of the connecting end 11 is circumferentially provided with at least three nut holes for placing the nut 3. The connecting end 11 also has bolt holes communicating with the nut holes and extending to the end face of the connecting end 11 for the heat-insulating screw 2 to pass through. The nut 3 corresponds to each of the nut holes and is disposed within the nut holes. The heat-insulating screw 2 is used to pass through the connecting holes on the rear section 4 and the bolt holes on the connecting end 11 to connect with the nut 3, thereby connecting the rear section 4 and the connecting end 11.

[0028] When connecting the radome 1 to the rear section 4, at least three nut holes are spaced circumferentially on the inner wall of the connecting end 11 of the radome 1, and bolt holes communicating with the nut holes are provided on the connecting end 11. Nuts 3 are placed in the corresponding nut holes, and the connecting holes passing through the rear section 4 and the bolt holes on the connecting end 11 are connected to the nuts 3. This connects the rear section 4 and the connecting end 11. Furthermore, both the heat-insulating screws 2 and nuts 3 are made of high-temperature resistant materials. Using heat-insulating screws 2 and nuts 3 to connect the rear section 4 and the radome 1 improves the connection strength between the rear section 4 and the radome 1 and allows it to withstand higher temperatures. It can withstand large alternating loads and avoids the risks of uncontrollable radome debonding and high-temperature carbonization debonding of the adhesive layer in existing adhesive-type radomes. It also withstands long-term high temperatures and has reliable connection strength.

[0029] In this example, the nut hole on the radome 1 is made as small as possible, just enough to accommodate the nut 3, so as to avoid weakening the load-bearing capacity of the radome 1. The size of the nut 3 matches the width and depth of the nut hole on the radome 1 to avoid weakening the load-bearing capacity of the radome.

[0030] In addition, in this example, the nut holes spaced circumferentially on the inner wall of the connecting end 11 of the radome 1 are arranged along the radial direction of the radome 1, with a distance set between them from the end face of the connecting end 11. The bolt holes are arranged along the axial direction of the radome 1, extending from the nut holes to the end face of the connecting end 11.

[0031] In addition, the outer cover, namely the antenna cover 1, is made of quartz fiber reinforced composite quartz ceramic for heat protection, ablation protection and bearing external aerodynamic loads. It has a strength of up to 35MPa, good toughness and high temperature erosion resistance.

[0032] In some optional embodiments, a heat shield 5 is also provided inside the radome 1. In this example, the rear section 4 connected to the radome 1 is the seeker head. High-temperature aerodynamic heat from the stagnation point and the large area heats the air temperature inside the radome 1. In addition to conduction, the hot air also radiates heat to the seeker head. Providing a heat shield 5 inside the radome 1 can block some of the heat from reaching the outside of the seeker head, preventing excessive radiative heating of the seeker head.

[0033] In some optional embodiments, the heat shield 5 includes two layers of housing together. In this embodiment, by using two layers of housing to form the heat shield 5, the seeker head is isolated from the hot air twice, which can prevent the air from radiating high-temperature heat to the seeker head. After multiple heat insulation by the outer layer of the antenna cover 1 and the heat shield 5, the air temperature at the seeker head can be reduced to 56°C.

[0034] In some alternative embodiments, both covers are cup-shaped with openings facing the connecting end 11, and the sidewalls of the two covers are in close contact with each other, with their bottoms spaced apart.

[0035] In this embodiment, by designing the two layers of the cover in a cup shape, with their sidewalls tightly attached and their bottoms spaced apart, a cavity is formed between the two layers. This cavity effectively blocks external heat. Furthermore, since the openings of both layers face the connecting end 11, another cavity can be formed between the inner layer and the end face of the connecting end 11. Thus, the two layers of the cover create two cavities, resulting in even better heat insulation. In other embodiments, a vacuum can be drawn into the cavity between the two layers to further enhance the heat insulation effect.

[0036] In some alternative embodiments, both layers of the cover are made of aerogel. In this embodiment, the thermal conductivity of the aerogel is 0.03 W / (m·K), and using aerogel for the cover can better block external heat.

[0037] In some optional embodiments, a heat insulation pad 6 is provided on the end face of the connection end 11. In this embodiment, the heat insulation pad 6 is made of quartz fiber reinforced resin, which has a lower thermal conductivity than ceramic, reducing heat transfer between the radome 1 and the rear section 4, thereby lowering the temperature inside the rear section 4.

[0038] In some alternative embodiments, the heat insulation pad 6 has a protrusion 61 on the side near the connection end 11 for engaging with the inside of the connection end 11.

[0039] In this embodiment, the heat insulation pad 6 is secured to the connecting end 11 by the protrusion 61, which facilitates installation.

[0040] In addition, by using a two-layer cover as the heat shield 5, the heat shield 5 can be held against the protrusion 61 that is clipped inside the connecting end 11, further reducing the transfer of heat from the outside to the rear section 4. During installation, after the heat shield 5 is positioned with the inner surface of the antenna cover 1, it is directly pressed together by the protrusion 61 of the heat shield pad 6.

[0041] In some optional embodiments, the outer diameter of the heat insulation pad 6 is smaller than the outer diameter of the connecting end 11. In this embodiment, designing the outer diameter of the heat insulation pad 6 to be smaller than the outer diameter of the connecting end 11 allows the heat insulation pad 6 to be located inside the connection between the connecting end 11 and the rear compartment 4. This serves both to transfer heat from the radome 1 to the rear compartment 4 and to ensure the connection strength between the radome 1 and the rear compartment 4.

[0042] In some optional embodiments, a protective sleeve 7 is fitted over the nut 3. The protective sleeve 7 is made of copper. In this embodiment, fitting the protective sleeve 7 over the nut 3 reduces the contact stress between the embedded nut 2 and the radome 1 during stress, thus preventing stress damage to the radome 1. Using copper to encase the nut 3 embedded in the radome 1 reduces the contact stress between the nut 3 embedded in the radome 1 and the ceramic radome 1 during stress. The nut 3 and the protective sleeve 7 provide a force transmission path between the front and rear mating surfaces, and the copper plating provides better stress uniformity, preventing concentrated stress from damaging the radome 1.

[0043] In addition, in this scheme, the cross-section of the radome 1 is optimally circular, the nut 3 is made of stainless steel, which is low in cost and there are 8 of them. There are also 8 corresponding heat insulation screws 2, and 8 bolt holes and nut holes to provide better uniformity of force distribution. By being embedded in the side wall of the connecting end 11 of the radome 1 made of ceramic bottle, it plays the role of connecting nut, which can avoid the commonly used adhesive design of radome 1 and the expensive Invar ring connection scheme.

[0044] In some optional embodiments, the heat-insulating screw 2 includes a screw and a heat-insulating ring, with the heat-insulating ring fitted onto the screw. The heat-insulating screw 2 is made of a screw and a heat-insulating ring, with the heat-insulating ring on the outer side of the screw 2 occupying as large an area as possible inside the nut 3. The space between the bolt hole and the screw is also filled with the heat-insulating ring to reduce heat transfer to the rear compartment. The size is M8. A heat-insulating pad 6 reduces the metal-to-metal contact area between the heat-insulating screw 2 and the rear compartment 4, further reducing heat transfer from the heat-insulating screw 2 to the rear compartment 4. The embedded nut connection and the heat-insulating screw 2 can control the mating surface temperature of the rear compartment 4 at 190°C. The rear compartment 4 is made of mature, low-cost aluminum alloy, titanium alloy, or carbon fiber.

[0045] In summary, this solution utilizes an embedded nut and heat-insulating screw force transmission method, an inner and outer shroud combination heat insulation method, and a heat-insulating pad and heat-insulating screw thermal resistance method. This overcomes the shortcomings of traditional radomes that use low-density expansion alloys and adhesive debonding, ensuring the low-temperature operating environment of the internal seeker and ensuring that the radome meets the requirements for long-term thermal environment use in terms of strength and temperature. At the same time, it has minimal impact on electromagnetic field transmission, realizing the reliable use of brittle ceramic radomes in long-endurance hypersonic aircraft.

[0046] The ceramic material serves as the radome, ensuring signal transmission while withstanding external aerodynamic heating. A double-layered heat shield protects the seeker head's operating temperature. The embedded nut, made of high-temperature resistant alloy, withstands high temperatures and connects to the rear structure via its threaded hole, avoiding common adhesive designs. A sheath reduces contact stress between the embedded nut and the ceramic material. A heat-insulating pad reduces heat transfer at the mating surfaces. Heat-insulating screws minimize the heat transfer path by reducing the metal-to-metal contact area. This design ensures the entire structure withstands long-term high temperatures, provides reliable connection strength, and offers excellent insulation, avoiding the uncontrollable debonding of adhesive-bonded radomes and the risk of high-temperature carbonization and debonding of adhesive layers. It can be used in long-endurance hypersonic vehicles and for force transmission and heat insulation between brittle and tough materials.

[0047] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0048] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0049] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A radome connection structure for an aircraft, characterized in that, include: The radome (1) is made of ceramic material and includes a connecting end (11) for connecting to the rear section (4). The inner wall of the connecting end (11) is provided with at least three nut holes for placing nuts (3) at circumferential intervals. The connecting end (11) is also provided with bolt holes that communicate with the nut holes and extend to the end face of the connecting end (11) for passing through the heat insulation screw (2). Nuts (3) corresponding to each of the said nut holes are provided in the said nut holes, and the size of the nuts (3) matches the width and depth of the said nut holes; A heat-insulating screw (2) corresponding to the nut (3) is used to pass through the connecting hole on the rear compartment (4) and the bolt hole on the connecting end (11) to connect the rear compartment (4) and the connecting end (11). The nut (3) is fitted with a protective sleeve (7) on the outside, and the sleeve is made of copper. The antenna cover (1) is also provided with a heat insulation cover (5); the heat insulation cover (5) includes two layers of cover together; both layers of cover are cup-shaped, with their openings facing the connection end (11), and the side walls of the two layers of cover are in close contact with each other, with their bottoms spaced apart; the cavity formed between the two layers of cover is evacuated.

2. The aircraft radome connection structure as described in claim 1, characterized in that: Both of the aforementioned cover layers are made of aerogel.

3. The aircraft radome connection structure as described in claim 1, characterized in that: A heat insulation pad (6) is provided on the end face of the connecting end (11).

4. The aircraft radome connection structure as described in claim 3, characterized in that: The heat insulation pad (6) has a protrusion (61) on the side near the connecting end (11) for locking inside the connecting end (11).

5. The aircraft radome connection structure as described in claim 3, characterized in that: The outer diameter of the heat insulation pad (6) is smaller than the outer diameter of the connecting end (11).

6. The aircraft radome connection structure as described in claim 1, characterized in that: The heat-insulating screw (2) includes a screw and a heat-insulating ring, the heat-insulating ring being fitted onto the screw.

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