Wave-transparent protection device for return type rocket navigation radar altimeter

Abstract

The embodiment of the utility model provides a wave-transparent protection device for a return type rocket navigation radar altimeter, and belongs to the technical field of return type rocket navigation radars. The wave-transparent protective device comprises an aluminum alloy support base, a wave-transparent protective layer and a wave-transparent protective layer, wherein the aluminum alloy support base is of an inverted T-shaped support structure; the modified CE resin shell cover covers the aluminum alloy bracket base to form a closed cavity; wherein the cantilever of the T-shaped support structure divides the closed cavity into a first closed sub-cavity and a second closed sub-cavity, the first closed sub-cavity accommodates an electrical assembly, and a radar module is arranged on the back surface of the cantilever in the second closed sub-cavity. According to the utility model, the modified CE resin shell cover is used, so that the strength requirement is met, the cost is low, the installation is easy, and an extra heat-proof coating does not need to be used.

Description

Technical Field

[0001] The utility model belongs to the technical field of returnable rocket navigation radars, in particular to a wave-transmitting protective device for a returnable rocket navigation radar altimeter. Background Art

[0002] During the reentry and landing process of a reusable launch vehicle or other aircraft, a radar altimeter is required to accurately measure altitude. However, during operation, the radar altimeter's housing must not only be heat-resistant and robust, but also transparent to electromagnetic waves. Therefore, radar altimeters are often equipped with protective devices.

[0003] Currently, there are different types of protective devices for navigation altimeter radars:

[0004] 1) Metal shell with windowed wave-transmitting protective device: This all-metal shell is heavy. While it provides sufficient strength, it will shield electromagnetic waves and requires additional wave-transmitting windows, which complicates the structure and assembly of the wave-transmitting protective device.

[0005] 2) Ceramic-based wave-transmitting protective device: uses quartz fiber, silicon carbide fiber or special ceramic shell, has high strength and can withstand high temperatures above 1000 degrees, but is expensive and heavy.

[0006] 3) Wave-transmitting protective devices based on a conventional resin combined with a thermal barrier coating: Materials such as glass fiber reinforced plastic are low-cost and provide good wave transmittance, but their thermal insulation properties are insufficient, making them susceptible to failure under the high-speed aerodynamic heating of a returning rocket. This makes it difficult to maintain internal operating temperatures, and their structural strength is low. If protection against high temperatures or thermal erosion is required, a thermal barrier coating must be applied, which is a complex process and increases costs.

[0007] 4) New composite material wave-transmitting protective devices: These use a shell made of graphene aerogel composite materials, which offer excellent strength, high-temperature resistance, and wave-transmitting properties. However, these wave-transmitting protective devices require the most complex manufacturing process and are the most expensive.

[0008] In summary, the existing wave-transmitting protective devices generally have at least some of the following deficiencies or defects:

[0009] a) The overall design is not conducive to the application of reusable rockets: The protective devices of traditional navigation and altitude measurement radars are generally large in size. From the perspective of reducing the drag of the entire rocket and protecting against heat during return, the excessive size makes it difficult to place them on the side wall of the rocket body. Therefore, traditional navigation and altitude measurement radars mostly adopt a split design, which further complicates the electrical products on the rocket and is not conducive to rapid assembly and testing and cost reduction.

[0010] b) The shell's wave transmission, heat protection, strength, and cost are difficult to achieve. Low-cost materials have insufficient thermal management capabilities, and applying thermal coatings increases material and installation costs. High-quality thermal protection materials are expensive, and their protection far exceeds the rocket's requirements, wasting material performance. High-strength metal materials struggle to achieve both wave transmission and precision.

[0011] c) The wave-transparent protective device is highly coupled with the internal radar antenna, making it difficult to use it universally. This limits the product's usage scenarios and increases the hidden costs of mold opening and additional design. Utility Model Content

[0012] The purpose of the present utility model is to at least partially solve the above-mentioned technical problems and to provide a wave-transmitting protection device for a returning rocket navigation radar altimeter.

[0013] The main task of the present invention is to solve at least one or at least part of the following technical problems:

[0014] The use of a new modified CE resin (a combination of cyanate ester and quartz fiber) meets strength requirements while being low-cost and easy to install, eliminating the need for additional heat-resistant coatings.

[0015] A highly versatile wave-transmitting thermal protection device has been designed for use with navigation radar altimeters. It is suitable for installation in various types of industrial radars. It maintains an internal device temperature of ≤85°C in an external high-temperature environment of 150°C, meets 95% wave transmission, and features a hermetic structure. Under random vibration, the cover deformation is less than 1mm.

[0016] The wave-transmitting heat protection device is compact and weighs no more than 4kg including the radar, meeting the space restrictions on the rocket body. The radial protrusion height is ≤10cm, and the shape does not significantly increase aerodynamic drag and thermal erosion.

[0017] Unique electrical interface design, which is protective and convenient for connection. The electrical interface is easy to install and seal.

[0018] While meeting the above functional performance requirements, reduce material costs as much as possible and avoid adding additional high-cost heat-resistant coatings.

[0019] In one aspect of the present invention, a wave-transmitting protection device for a recoverable rocket navigation radar altimeter is provided, the wave-transmitting protection device comprising:

[0020] Aluminum alloy bracket base, the aluminum alloy bracket base is an inverted T-shaped bracket structure;

[0021] A modified CE resin housing covers the aluminum alloy bracket base to form a closed cavity;

[0022] The cantilever of the T-shaped bracket structure divides the closed cavity into a first sub-closed cavity and a second sub-closed cavity. The first sub-closed cavity accommodates electrical components, and a radar module is arranged on the back of the cantilever in the second sub-closed cavity.

[0023] In some embodiments, the modified CE resin housing cover comprises a composite material layer of a cyanate ester layer overlying a quartz fiber layer;

[0024] The thickness of the modified CE resin outer shell is less than 3 mm.

[0025] In some embodiments, the modified CE resin housing has an asymmetric streamlined surface.

[0026] In some embodiments, the cantilever has a built-in tilt angle equal to 4 degrees.

[0027] In some embodiments, the distance between the radar module, the electrical components and the inner wall of the modified CE resin housing is greater than or equal to 2 mm.

[0028] In some embodiments, the radial protrusion height of the wave-transparent protection device is less than or equal to 10 cm.

[0029] In some embodiments, a plurality of spaced apart fixing holes are provided on the side surface of the aluminum alloy bracket base.

[0030] In some embodiments, the modified CE resin housing cover is fixed to the fixing holes of the aluminum alloy bracket base by a plurality of metal bolts, and the fixing holes are filled with sealant covering the metal bolts.

[0031] In some embodiments, an electrical interface is provided on the back side of the aluminum alloy bracket base within the first sub-enclosed cavity, and the electrical interface is an electrical socket for cooperating with the electrical interface of the rocket body. The electrical components include a circuit board and a circuit protection device, which are respectively provided on the front side of the aluminum alloy bracket base within the first sub-enclosed cavity.

[0032] In some embodiments, a plurality of spaced-apart, outwardly protruding screw lugs for fixing to the rocket body are provided on the side of the aluminum alloy bracket base.

[0033] The wave-transmitting protection device for a recoverable rocket navigation radar altimeter according to an embodiment of the present invention has at least one of the following advantages:

[0034] The wave-transmitting protection device for the returning rocket navigation radar altimeter in the embodiment of the present utility model realizes the wave-transmitting, heat-insulating and load-bearing coordinated protection of the returning rocket radar altimeter in extreme environments through the integrated design of material structure and function, thereby solving the urgent need for lightweight, high-reliability and low-cost navigation measurement of reusable rockets.

[0035] The wave-transmitting protection device for a returning rocket navigation radar altimeter provided by the utility model is a highly versatile wave-transmitting heat-protection device for navigation radar altimeters. It can be applied to the installation of various common industrial-grade radars. In an external high-temperature environment of 150°C, it maintains an internal device temperature of ≤85°C, meets a wave transmittance of 95%, and the cover deformation under random vibration is less than 1mm.

[0036] The wave-transparent protection device for the return-type rocket navigation radar altimeter provided by the utility model has a compact structure and a weight including the radar of no more than 4 kg; it meets the installation space limitation of the rocket body, the radial protrusion height is ≤10 cm, and the shape does not significantly increase the aerodynamic resistance and thermal flow scouring; the electrical interface is protected and easy to connect, and the structural interface is easy to install and seal. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] These and / or other aspects and advantages of the present invention will become apparent and readily understood from the following description of preferred embodiments in conjunction with the accompanying drawings, in which:

[0038] Figure 1 This is a schematic diagram of the three-dimensional structure of a wave-transmitting protection device for a recoverable rocket navigation radar altimeter according to one embodiment of the present utility model;

[0039] Figure 2 yes Figure 1 A schematic diagram of the structure of the wave-transmitting protective device with the modified CE resin outer shell removed is shown;

[0040] Figure 3 yes Figure 1 A side view of the aluminum alloy bracket base is shown;

[0041] Figure 4 yes Figure 1 Schematic diagram of the structure of the back side of the aluminum alloy bracket base is shown. DETAILED DESCRIPTION

[0042] The following examples and accompanying drawings further illustrate the technical solutions of the present invention. In the specification, the same or similar reference numerals indicate the same or similar components. The following description of the embodiments of the present invention with reference to the accompanying drawings is intended to explain the overall technical concept of the present invention and should not be construed as limiting the present invention.

[0043] See also Figure 1 , shows a wave-transparent protection device 100 for a recoverable rocket navigation radar altimeter according to an embodiment of the present utility model. Figure 2The schematic diagram shows the structure with the modified CE resin housing cover 20 removed. As shown in the figure, the wave-transmitting protective device 100 comprises two main parts: an aluminum alloy support base 10 and a modified CE resin housing cover 20. Specifically, the aluminum alloy support base 10 is an inverted T-shaped support structure; the modified CE resin housing cover 20 covers the aluminum alloy support base 10, forming a closed cavity. The cantilever 11 of the T-shaped support structure divides the closed cavity into a first sub-enclosed cavity 101 and a second sub-enclosed cavity 102. The first sub-enclosed cavity 101 accommodates the electrical component 200, and the radar module 300 is disposed on the back of the cantilever 11 within the second sub-enclosed cavity 102.

[0044] The modified CE resin outer shell 20, serving as a wave-transmitting heat-shielding layer, is constructed from a modified CE resin layer (a laminated layer of quartz fiber and cyanate ester). As discussed in the background technology section, the design objective of this embodiment is to provide a novel wave-transmitting heat-shielding layer that not only possesses sufficient strength and heat-shielding properties but also transmits electromagnetic waves. The use of a laminated quartz fiber and cyanate ester layer as the wave-transmitting heat-shielding material not only meets strength requirements but is also cost-effective and easy to install, eliminating the need for an additional heat-shielding coating.

[0045] The modified CE resin housing cover 20 has an asymmetric streamlined surface. In one embodiment, for example, the dimensions of the modified CE resin housing cover 20 are designed to be 213 mm×185 mm×94 mm.

[0046] In one embodiment, according to the wave transmission performance requirements, the required thickness is calculated to be 2.8 mm, the dielectric constant is 3.43, and the dielectric loss is 0.005.

[0047] The wall thickness of the modified CE resin housing 20 is determined and optimized as follows:

[0048] First, the modified CE resin outer shell 20 is made of a modified CE resin material (a laminate of quartz fiber and cyanate resin layers). This material exhibits excellent high-temperature resistance and mechanical properties. Its dielectric constant is 3.43 and its dielectric loss is 0.005, making it an excellent heat-resistant and wave-transmitting material. The thickness of the modified CE resin outer shell 20 is designed to be 2.8 mm, resulting in a calculated theoretical wave transmittance of 95.8%, meeting the requirements for use in recoverable rocket navigation radars.

[0049] After completing the wave-transmitting design, simulation calculations were performed taking into account the heat protection requirements. Under the target thermal environment, the internal operating temperature requirement of no more than 85 degrees Celsius was met, and it can be used in general industrial-grade radar products.

[0050] In summary, the thickness of the modified CE resin housing cover 20 is less than 2.8 mm.

[0051] In addition, the aluminum alloy bracket base 10 is designed as a load-bearing layer and adopts 2A12-T4 aluminum alloy bracket with a yield strength of 259MPa and a thermal conductivity coefficient of 130W / (m·K), which meets the strength requirements of the return rocket and is low-cost and easy to install.

[0052] See also Figure 3 , shows a side view of the aluminum alloy bracket base 10. The built-in tilt angle of the cantilever 11 is less than or equal to 4 degrees. Therefore, it can be seen that the built-in tilt angle of the cantilever 11 meets the radar signal deflection requirements and reduces the interference of multipath reflections from the rocket body.

[0053] like Figure 2 and Figure 3 As shown, a T-shaped bracket structure was designed to ensure structural strength, achieving product fixation and functional zoning. The radar module 300 for ranging is installed at the bottom of the illustrated page, while the electrical interface and circuit board structures are located above the illustrated page, ensuring that the upper and lower sections do not interfere with each other. The cantilever 11 is kept as short as possible to minimize the overall size of the device and reduce aerodynamic effects. The T-shaped bracket structure has a first-order natural frequency of 1950 Hz and a maximum deformation of 0.02 mm, meeting the requirements for use on reusable rockets.

[0054] The rocket flight profile mainly consists of the following two parts:

[0055] a) Ascent phase: The rocket ignites and takes off, gradually rising from 0 m to about 110 km in altitude. During this phase, the wave-transmitting protection device 100 of this embodiment does not need to work, but only needs to ensure heat protection.

[0056] b) Return phase: The rocket re-enters the atmosphere from its highest point, and the altitude gradually decreases from 110 km. When the altitude falls below 1 km, the internal radar module 300 starts to operate. The wave-transmitting protective device 100 of this embodiment ensures both wave-transmitting and heat-protection functions.

[0057] Furthermore, the radial projection height of the wave-transparent protection device 100 is less than or equal to 9.5 cm. This satisfies the space constraints imposed on the rocket body, which generally limit the radial projection height to less than or equal to 10 cm. This height, combined with the asymmetric streamlined surface of the modified CE resin outer shell 20, minimizes aerodynamic impact by not significantly increasing aerodynamic drag and thermal erosion.

[0058] like Figure 2As shown, the electrical component 200 is arranged in the first sub-enclosed cavity 101, and the radar module 300 is installed on the back of the cantilever 11 and is located in the second sub-enclosed cavity 102, so that the space in the first sub-enclosed cavity 101 retained above the cantilever 11 can be used to protect the electrical component 200, which usually includes a circuit board and a circuit protection device.

[0059] In this embodiment, by arranging the various components in a three-dimensional conformal manner inside the wave-transparent protection device 100, the distance between the radar module 300, the electrical component 200 and the inner wall of the modified CE resin housing 20 is greater than or equal to 2 mm, thereby avoiding vibration interference.

[0060] In one embodiment, the side of the aluminum alloy bracket base 10 is provided with a plurality of spaced apart fixing holes 12. The modified CE resin housing cover 20 is fixed to the fixing holes 12 of the aluminum alloy bracket base 10 via a plurality of metal bolts 13, and the fixing holes 12 are filled with a sealant covering the metal bolts 13. Thus, by attaching the aluminum alloy bracket base 10 and the modified CE resin housing cover 20 by installing the metal bolts 13 in the plurality of fixing holes 12 spaced apart on the side periphery of the aluminum alloy bracket base 10, and then sealing these fixing holes 12 with a sealant, both fixing and thermal protection are achieved.

[0061] In addition, a plurality of spaced apart screw-on lugs 14 protruding outward are provided on the side surface of the aluminum alloy bracket base 10. The entire wave-transparent protection device 100 is fixed to the side wall of the rocket through the through holes on the screw-on lugs 14, for example, by being screwed to the side wall of the rocket through bolts passing through the through holes.

[0062] like Figure 4 As shown, an electrical interface 103 is provided on the back of the aluminum alloy bracket base 10 in the first sub-enclosed cavity 101. The electrical interface 103 is an electrical socket for cooperating with the electrical interface of the rocket body. As mentioned above, the electrical component 200 includes a circuit board and a circuit protection device, which are respectively arranged on the front of the aluminum alloy bracket base 10 in the first sub-enclosed cavity 101.

[0063] The wave-transmitting protection device for a recoverable rocket navigation radar altimeter according to an embodiment of the present invention has at least one of the following advantages:

[0064] The wave-transmitting protection device for the returnable rocket navigation radar altimeter in the embodiment of the present utility model realizes the wave-transmitting, heat-insulating and load-bearing coordinated protection of the returnable rocket radar altimeter in extreme environments through the integrated design of materials, structure and function, and solves the urgent need for lightweight, highly reliable and low-cost navigation measurement of reusable rockets.

[0065] The wave-transmitting protection device for a returning rocket navigation radar altimeter provided by the utility model is a highly versatile wave-transmitting heat-protection device for navigation radar altimeters. It can be applied to the installation of various common industrial-grade radars. In an external high-temperature environment of 150°C, it maintains an internal device temperature of ≤85°C, meets a wave transmittance of 95%, and the cover deformation under random vibration is less than 1mm.

[0066] The wave-transparent protection device for the return-type rocket navigation radar altimeter provided by the utility model has a compact structure and a weight including the radar of no more than 4 kg; it meets the installation space limitation of the rocket body, the radial protrusion height is ≤10 cm, and the shape does not significantly increase the aerodynamic resistance and thermal flow scouring; the electrical interface is protected and easy to connect, and the structural interface is easy to install and seal.

[0067] Although some embodiments of the overall technical concept of the present invention have been shown and described, those skilled in the art will understand that changes can be made to these embodiments without departing from the principles and spirit of the overall technical concept, and the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A wave-transmitting protective device for a returning rocket navigation radar altimeter, characterized in that: The wave-transmitting protective device comprises: Aluminum alloy bracket base, the aluminum alloy bracket base is an inverted T-shaped bracket structure; A modified CE resin housing covers the aluminum alloy bracket base to form a closed cavity; The cantilever of the T-shaped bracket structure divides the closed cavity into a first sub-closed cavity and a second sub-closed cavity. The first sub-closed cavity accommodates electrical components, and a radar module is arranged on the back of the cantilever in the second sub-closed cavity.

2. The wave-transmitting protection device for a recoverable rocket navigation radar altimeter according to claim 1, characterized in that: The modified CE resin housing cover comprises a composite material layer of a cyanate ester layer covering a quartz fiber layer; The thickness of the modified CE resin outer shell is less than 3 mm.

3. The wave-transmitting protection device for a recoverable rocket navigation radar altimeter according to claim 2, characterized in that: The modified CE resin outer shell adopts an asymmetric streamlined curved surface.

4. The wave-transmitting protection device for a recoverable rocket navigation radar altimeter according to claim 1, characterized in that: The built-in inclination angle of the cantilever is equal to 4 degrees.

5. The wave-transmitting protection device for a recoverable rocket navigation radar altimeter according to claim 4, characterized in that: The distance between the radar module, the electrical components and the inner wall of the modified CE resin housing is greater than or equal to 2 mm.

6. The wave-transmitting protection device for a recoverable rocket navigation radar altimeter according to claim 5, characterized in that: The radial protrusion height of the wave-transmitting protective device is less than or equal to 10 cm.

7. The wave-transmitting protection device for a recoverable rocket navigation radar altimeter according to claim 6, characterized in that: A plurality of spaced apart fixing holes are provided on the side surface of the aluminum alloy bracket base.

8. The wave-transmitting protection device for a recoverable rocket navigation radar altimeter according to claim 7, characterized in that: The modified CE resin housing cover is fixed to the fixing holes of the aluminum alloy bracket base through a plurality of metal bolts, and the fixing holes are filled with sealant covering the metal bolts.

9. The wave-transmitting protection device for a recoverable rocket navigation radar altimeter according to any one of claims 1 to 8, characterized in that: An electrical interface is provided on the back of the aluminum alloy bracket base in the first sub-enclosed cavity. The electrical interface is an electrical socket for cooperating with the electrical interface of the rocket body. The electrical components include a circuit board and a circuit protection device, which are respectively provided on the front of the aluminum alloy bracket base in the first sub-enclosed cavity.

10. The wave-transmitting protection device for a recoverable rocket navigation radar altimeter according to claim 9, characterized in that: The side of the aluminum alloy bracket base is provided with a plurality of spaced apart and outwardly protruding screw ears for fixing to the rocket body.

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