Installation method of sharp-point hard foam darkroom material suitable for extreme use environment

Abstract

The present application relates to the assembly technology of foam darkroom material, in particular to a mounting method of sharp cone hard foam darkroom material suitable for extreme use environment, and belongs to the field of material engineering. The steel wire barb method is adopted, a hole is first drilled in the middle of the bottom of the sharp cone hard foam darkroom material unit, then one end of a metal round rod is fixed on the bottom plate, the other end of the metal round rod is loaded with a steel wire shaped by moulding, and the steel wire is inserted into the hole in cooperation with the hole in the bottom of the hard foam darkroom material, the steel wire in the hole plays a rebounding role to make the end of the metal round rod embedded into the hole of the hard foam, and a barb hook is formed to tightly fix the sharp cone hard foam darkroom material unit so that it cannot be moved and rotated at will, and fast and stable installation is realized. The method can tightly connect the sharp cone structure hard foam darkroom material with the metal bottom plate, and can effectively solve the problem of mass installation of foam darkroom material used in extreme use environment.

Description

Technical Field

[0001] This invention relates to the assembly technology of foam anechoic chamber materials, specifically a method for installing a cone-shaped rigid foam anechoic chamber material suitable for extreme operating environments, belonging to the field of materials engineering. Background Technology

[0002] With the continuous development and progress of microwave electronic technologies such as antenna communication, electronic countermeasures, electromagnetic shielding, radar detection and stealth attack in both military and civilian fields, it is particularly necessary to accurately test and evaluate the electromagnetic wave absorption or scattering state of a target. This requires the establishment of a microwave anechoic chamber environment with extremely low scattering.

[0003] To create a microwave anechoic chamber environment, high-performance electromagnetic wave absorbing materials need to be filled and installed. To balance the requirements of high-efficiency absorption and lightweight design, designing the anechoic chamber material as a foamed cone structure is the only option. Different sizes of foam cones are designed according to the requirements of different electromagnetic wave bands, and different absorption components are used.

[0004] Currently, the most widely used anechoic chamber materials are still conventional anechoic chamber materials. To reduce manufacturing costs, a cone-shaped flexible foam resin (such as polyether resin foam or polyurethane resin foam) is used as a precursor. Conventional anechoic chamber materials are produced by impregnating the foam with a microwave-absorbing slurry and then curing it. Conventional anechoic chamber materials are suitable for room temperature environments, and the common installation method for conventional anechoic chamber materials is to bond the cone-shaped foam to the base plate using adhesive.

[0005] With the intensifying technological competition among global powers, the demand for detecting electromagnetic signals from targets in extreme environments such as high temperatures, ultra-low temperatures, high vacuum, electric arcs, strong particle radiation, and high-power antenna radiation is increasing. To address this, Chinese scientists have developed various specialized cone-shaped foam anechoic chamber materials suitable for these extreme environments, including cone-shaped carbon foam anechoic chamber materials, cone-shaped silicon carbide foam anechoic chamber materials, cone-shaped cyanate ester resin foam anechoic chamber materials, cone-shaped polyimide resin foam anechoic chamber materials, and cone-shaped phenolic resin foam anechoic chamber materials, among others. All of these foam anechoic chamber materials for extreme environments use rigid foam materials as their matrix and are collectively referred to as cone-shaped rigid foam anechoic chamber materials.

[0006] Conventional adhesive installation methods for anechoic chamber materials are unsuitable for rigid foam anechoic chamber materials used in extreme environments. Firstly, under significant temperature variations, the large difference in expansion coefficients between the rigid foam and the base plate can cause it to detach. Secondly, high temperatures, extremely low temperatures, electric arcs, or high-energy particle radiation can damage the adhesive, rendering it ineffective. Currently, the grooving method is primarily used to install anechoic chamber materials for extreme environments. This involves installing a grooving plate on the base plate, machining grooves on both sides of the bottom of the conical anechoic chamber material, and then sliding the material one by one into the grooving plate through the interaction between the grooves and the grooving plate, thus completing the installation. While the grooving method largely solves the installation problem of anechoic chamber materials for extreme environments, it suffers from two major drawbacks: First, when the foam pores of the anechoic chamber material are large, the machined grooves are difficult to stably fit with the grooving plate. Furthermore, the grooving method itself cannot tightly fix the anechoic chamber material to the base plate, making the loose material highly susceptible to collision damage or detachment when the base plate moves or rotates. Second, replacing damaged anechoic chamber material is cumbersome, requiring the removal of other materials from the same grooving plate, and potentially even disassembling the base plate. Therefore, further research and development of new methods for installing rigid foam anechoic chamber materials with pointed cone structures for extreme environments are needed. Summary of the Invention

[0007] The purpose of this invention is to provide an installation method for rigid foam anechoic chamber materials with pointed cones suitable for extreme operating environments. This method enables the rigid foam anechoic chamber material with pointed cone structure to be tightly connected to the metal base plate, which can effectively solve the problem of mass installation of foam anechoic chamber materials for extreme operating environments.

[0008] The technical solution of this invention is:

[0009] An installation method for a rigid foam anechoic chamber material suitable for extreme environments is characterized by employing a wire barb method. First, a hole is drilled in the center of the bottom of the rigid foam anechoic chamber material unit. Then, one end of a metal rod is fixed to the base plate, and the other end of the metal rod is loaded with a molded steel wire, which is inserted into the hole at the bottom of the rigid foam anechoic chamber material unit. The steel wire entering the hole has a spring-like effect, causing the end of the metal rod to embed into the rigid foam hole, forming a barb hook that prevents the rigid foam anechoic chamber material unit from moving or rotating arbitrarily, thus achieving rapid and stable installation.

[0010] The installation method for a rigid foam anechoic chamber material suitable for extreme environments involves first fixing a metal rod to the base plate, and then tightly connecting the rigid foam anechoic chamber material unit to the metal rod using a wire hook method. The specific installation process is as follows:

[0011] (1) Drilling holes in the base plate

[0012] Based on the installation concept of the pointed rigid foam anechoic chamber material unit with the top facing the electromagnetic wave and the bottom fixed to the base plate by steel wire hooks and metal rods, it is necessary to comprehensively consider the structural size and weight of the pointed rigid foam anechoic chamber material unit, design the number and size of the metal rods, and then determine the location distribution and size of the installation holes to be drilled on the base plate. The base plate is a metal plate, and the drilled holes are flat-bottomed internal thread holes. The major diameter D of the internal thread is required to be 4mm to 20mm, and the hole depth H1 is required to be 3mm to 15mm.

[0013] (2) Drilling of the cone-shaped rigid foam anechoic chamber material unit

[0014] Based on the design of the number and size of the metal rods, a carbide drill bit is used to drill a hole in the center at the bottom of each cone-shaped rigid foam anechoic chamber material unit. The hole diameter is D and the hole depth H2 is required to be 15mm to 100mm.

[0015] (3) Molding and shaping of steel wire

[0016] The steel wire is 15mm to 70mm in length and d1 is 0.3mm to 2mm in diameter. First, the steel wire is shaped into an arc shape in the middle and the two ends are moderately turned outward by applying pressure through a mold. The outward turning angle α is required to be 30° to 45° and the length of the outward turning end is 1mm to 6mm.

[0017] (4) Design and fabrication of metal round rods

[0018] First, each metal rod is integrally machined into two cylindrical sections, one thick and one thin. The thick cylinder has a diameter of D and a length of H1. It is further machined into a screw rod with an external thread major diameter of D, which matches the internal thread on the base plate to form a screw thread. The thin cylinder has a diameter of d2 and a length of H2. The end of the thin cylinder is further machined into a conical end with a height of 2mm to 5mm, which matches the upper conical part of the bottom hole of the pointed cone rigid foam anechoic chamber material unit. Two loading holes are drilled radially in the thin cylinder for loading steel wire. The two loading holes are orthogonal and interpenetrating, and the diameter of each hole is 2 to 4 times the diameter of the steel wire d1. The center distance of the loading hole from the bottom of the cone is 0.5mm to 3mm, and it is as close as possible to the end of the thin cylinder.

[0019] (5) Loading of shaped steel wire

[0020] First, vertically fasten all the metal rods to the base plate with screws. Then, alternately pass the plastic steel wire through the two orthogonal loading holes of each metal rod. Place the plastic steel wires on both sides of the thin cylinder as symmetrically as possible, and make sure that the arc-shaped opening of the plastic steel wire faces the mounting base plate.

[0021] (6) Insertion of the cone-shaped rigid foam anechoic chamber material unit

[0022] Each cone-shaped rigid foam anechoic chamber material unit is inserted into the bottom hole and the thin cylindrical part of the metal rod. The insertion is stopped when the unit is tightly attached to the base plate. The steel wire entering the hole has a rebound effect, which allows the outward-curved end to be embedded in the foam hole, forming barbs to hook the anechoic chamber material, thereby achieving rapid and stable installation of the cone-shaped rigid foam anechoic chamber material unit.

[0023] The method for installing a rigid foam anechoic chamber material suitable for extreme operating environments uses a rigid foam anechoic chamber material unit with a square base and a four-cornered pyramidal structure. The material can be silicon carbide-based foam anechoic chamber material, carbon-based foam anechoic chamber material, cyanate ester resin-based foam anechoic chamber material, polyimide resin-based foam anechoic chamber material, or phenolic resin-based foam anechoic chamber material.

[0024] The installation method of the pointed rigid foam anechoic chamber material applicable to extreme use environments is described above, and the metal round rod material used is selected from aluminum alloy, bronze, carbon steel or stainless steel.

[0025] The installation method of the pointed rigid foam anechoic chamber material applicable to extreme use environments uses carbon steel or stainless steel as the steel wire material.

[0026] The method described above is for installing a rigid foam anechoic chamber material with pointed tips suitable for extreme environments. The steel wire is shaped by applying pressure with a mold. The arc design in the middle allows the steel wire to be symmetrically hung on both sides of the metal rod. The outward-turned design of both ends ensures that the ends of the steel wire are fully embedded in the foam holes when the wire rebounds, forming barbs that can hook the anechoic chamber material.

[0027] The method for installing a rigid foam anechoic chamber material suitable for extreme environments involves inserting the thin cylindrical portion of a metal rod into the bottom hole of the rigid foam anechoic chamber material unit, wherein the diameter d2 of the thin cylinder is smaller than the diameter D of the hole.

[0028] The installation method of the pointed cone rigid foam anechoic chamber material applicable to extreme use environments adopts two steel wire loading holes with orthogonal and interpenetrating design, so that the steel wires are radially dispersed in the metal round rod, increasing the barb force; the number of steel wires loaded alternately orthogonally is controlled between 2 and 6, and the number of steel wires in each loading hole is 1 to 3. When the number of steel wires loaded in each loading hole exceeds 2, the steel wires are arranged sequentially in the horizontal direction.

[0029] The installation method of the pointed cone rigid foam anechoic chamber material applicable to extreme use environments is described above. The radial dimension of the metal round rod thin cylinder plus the steel wire is smaller than the bottom hole diameter of the pointed cone rigid foam anechoic chamber material unit: 2×d1+d2<D, where d1 is the diameter of the steel wire, D is the diameter of the hole, and d2 is the diameter of the thin cylinder.

[0030] The design concept of this invention is:

[0031] This invention addresses the installation problem of rigid foam anechoic chamber materials with a pointed cone structure in extreme operating environments. Given that the currently mainly used adhesive method has poor adaptability to extreme operating environments, and the grooving method has drawbacks such as unstable fixing of the anechoic chamber material, easy damage, and troublesome replacement of damaged parts, a new feasible installation method is proposed, namely: the steel wire barb method.

[0032] The specific design concept of the steel wire barb method proposed in this invention is as follows: one end of a metal rod is fastened to the base plate through a threaded opening, and the other end is loaded with a shaped steel wire, which is inserted into the bottom hole of the rigid foam anechoic chamber material. The steel wire entering the hole exerts a rebound effect, causing its end to embed into the foam hole, forming barbs that hook the anechoic chamber material, thereby achieving rapid and stable installation of the pointed rigid foam anechoic chamber material. The key to this design concept is the reasonable matching between the steel wire and the bottom hole of the pointed rigid foam anechoic chamber material. First, under the premise of satisfying the mechanical stability of the material insertion, the radial dimension of the metal rod plus the steel wire is controlled to be lower than the diameter of the bottom hole of the pointed rigid foam anechoic chamber material to avoid damaging the anechoic chamber material during insertion. Second, the steel wire needs to be shaped to ensure that the insertion of the pointed rigid foam anechoic chamber material is smooth and that the rebounding end of the steel wire can immediately and effectively embed into the foam hole at the end, so that the pointed rigid foam anechoic chamber material cannot move or rotate arbitrarily, achieving a tight connection between it and the metal rod and the base plate.

[0033] The electromagnetic wave absorption performance of the conical rigid foam anechoic chamber material is not deteriorated after a metal rod is inserted at the bottom, for the following reasons: (1) The conical anechoic chamber material mainly absorbs incident electromagnetic waves through multiple scattering, and the inserted metal rod is located at the bottom of the anechoic chamber material, so the amount of electromagnetic waves that may reach it is very small; (2) The very small amount of electromagnetic waves that may reach the metal rod will also be scattered and absorbed into the anechoic chamber material, and will not be reflected back from the anechoic chamber material. In addition, the closer the metal rod is to the top of the conical anechoic chamber material, the greater the possibility that it will "touch" the incident electromagnetic waves. In order to more effectively scatter and absorb electromagnetic waves, the end of the metal rod inserted into the anechoic chamber material is processed into a conical structure.

[0034] The present invention has the following advantages and beneficial effects:

[0035] 1. Solved the feasibility installation problem of the cone-shaped rigid foam anechoic chamber material for extreme use environments.

[0036] The steel wire hook method employed in this invention utilizes entirely metal structural components for design and installation. These metal components possess exceptional resilience to various extreme operating environments, surpassing the capabilities of both organic and inorganic adhesives. The metal rods and wires used in the steel wire hook method are inexpensive, and the machining of the metal rods and the molding of the wires are mature processes, enabling low-cost mass production. The insertion process of the steel wire hook method effectively embeds the wire ends into the foam pores, preventing the rigid, pointed foam anechoic chamber material from moving or rotating arbitrarily. This ensures a tight connection between the rigid foam anechoic chamber material and the metal rod, while also preventing the screw threads between the metal rod and the base plate from loosening. In conclusion, this invention, employing the steel wire hook method to install rigid, pointed foam anechoic chamber material, effectively addresses the challenges of adaptability and stability in extreme operating environments, and is therefore feasible.

[0037] 2. Enabled rapid installation and replacement of rigid cone foam anechoic chamber material for extreme operating environments.

[0038] The steel wire hook method employed in this invention is an insert-type assembly approach. This one-step insertion operation enables rapid installation of each cone-shaped rigid foam anechoic chamber material. When the cone-shaped rigid foam anechoic chamber material installed using the steel wire hook method is damaged during use and needs replacement, simply pull out the damaged cone-shaped rigid foam anechoic chamber material, hang a new shaped steel wire on the metal rod, and then insert the new cone-shaped rigid foam anechoic chamber material. In comparison, the commonly used adhesive method and the grooving method are not as fast in installation or as simple in after-sales replacement as the steel wire hook method.

[0039] In summary, this invention provides an installation method for rigid foam anechoic chamber materials with pointed tips suitable for extreme environments: the wire hook method. The wire hook method for installing rigid foam anechoic chamber materials solves the problems of adaptability to extreme environments and stability of the assembly structure, enabling rapid installation and simple replacement of the anechoic chamber material. The wire hook method has broad application prospects in the field of rigid foam anechoic chamber material assembly. Attached Figure Description

[0040] Figures 1-2 The integral structure of the cone-shaped rigid foam anechoic chamber material ( Figure 1 ) and axial section ( Figure 2 (Diagram)

[0041] In the figure, 1 is a cone-shaped rigid foam anechoic chamber material unit, and 2 are holes.

[0042] Figure 3 This is a schematic diagram of a molded steel wire. In the diagram, 3 represents the end portion, and 4 represents the middle arc-shaped portion.

[0043] Figure 4 This is a schematic diagram of a metal round rod. In the diagram, 5 is a thick cylinder with threads, 6 is a thin cylinder, 7 is a loading hole, and 8 is a conical end.

[0044] Figure 5 This is a schematic diagram of a metal rod loaded with two molded steel wires. In the diagram, 9 represents the molded steel wire and 10 represents the metal rod.

[0045] Figures 6-7 The process of inserting a metal rod into a rigid, pointed foam anechoic chamber material ( Figure 6 ) and end ( Figure 7 (Status diagram) Detailed Implementation

[0046] like Figures 1 to 7 As shown, in the specific implementation process, this invention proposes an installation method for a cone-shaped rigid foam anechoic chamber material suitable for extreme usage environments. First, a metal rod is fixed to the base plate. Then, the cone-shaped rigid foam anechoic chamber material unit is tightly connected to the metal rod using a wire hook method. The specific installation process is as follows:

[0047] (1) Drilling holes in the base plate

[0048] Based on the installation concept of the pointed rigid foam anechoic chamber material unit with the top facing the electromagnetic wave and the bottom fixed to the base plate by steel wire hooks and metal rods, it is necessary to comprehensively consider the structural size and weight of the pointed rigid foam anechoic chamber material unit, design the number and size of the metal rods, and then determine the location distribution and size of the installation holes to be drilled on the base plate. The base plate is a metal plate, and the drilled holes are flat-bottomed internal thread holes. The major diameter D of the internal thread is required to be 4mm to 20mm, and the hole depth H1 is required to be 3mm to 15mm.

[0049] (2) Drilling of the cone-shaped rigid foam anechoic chamber material unit

[0050] like Figures 1-2 As shown, based on the number and size design of the metal rods, a carbide drill bit is used to drill a hole in the center at the bottom of each cone-shaped rigid foam anechoic chamber material unit 1. The diameter of the hole 2 is D, and the hole depth H2 of the hole 2 is required to be 15mm to 100mm. The upper end of the hole 2 is conical.

[0051] (3) Molding and shaping of steel wire

[0052] like Figure 3 As shown, the steel wire is 15mm to 70mm long and d1 is 0.3mm to 2mm in diameter. First, the steel wire is shaped into a middle arc-shaped part 4 and two end parts 3 with moderate outward turning by applying pressure through a mold. The outward turning angle α (the angle between the end part 3 and the corresponding connection point of the middle arc-shaped part 4) is required to be 30° to 45° and the length of the outward turning end part is 1mm to 6mm.

[0053] (4) Design and fabrication of metal round rods

[0054] like Figure 4As shown, each metal bar is first integrally machined into two cylindrical sections, one thick and one thin. The thick cylinder has a diameter of D and a length of H1. It is further machined into a threaded rod (the threaded thick cylinder 5) with an external thread major diameter of D, which is matched with the internal thread on the base plate to form a screw thread. The thin cylinder 6 has a diameter of d2 and a length of H2. The end of the thin cylinder is further machined into a conical end 8 with a height of 2mm to 5mm, which matches the upper conical part of the bottom hole of the pointed rigid foam anechoic chamber material unit. Two loading holes 7 are drilled radially in the thin cylinder 6 for loading steel wire. The two loading holes 7 are alternately drilled. The diameter of each loading hole 7 is 2 to 4 times the diameter of the steel wire d1. The center distance of the loading hole is 0.5mm to 3mm from the conical bottom of the conical end 8, and it is as close as possible to the upper end of the thin cylinder 6.

[0055] (5) Loading of shaped steel wire

[0056] like Figures 4-5 As shown, first, all the metal rods 10 are vertically fastened to the base plate with screws. Then, the plastic steel wires 9 are alternately passed through the two orthogonal loading holes 7 of each metal rod 10. Each plastic steel wire 9 is placed symmetrically on both sides of the thin cylinder 6, and the arc-shaped opening of the plastic steel wire 9 faces the mounting base plate.

[0057] (6) Insertion of the cone-shaped rigid foam anechoic chamber material unit

[0058] like Figures 6-7 As shown, each cone-shaped rigid foam anechoic chamber material unit is inserted into the bottom hole and the thin cylindrical part of the metal rod. When it is pressed against the base plate, the insertion is stopped. The steel wire entering the hole has a rebound effect, which allows the outward-curved end to be embedded in the foam hole, forming barbs to hook the anechoic chamber material, thereby achieving rapid and stable installation of the cone-shaped rigid foam anechoic chamber material unit.

[0059] The process involves shaping the steel wire using a mold. This serves two purposes: firstly, the appropriate arc design allows the wire to be symmetrically hung on both sides of the metal rod; secondly, the outward-curving end design ensures the wire fully embeds into the foam holes upon rebound, forming barbs that hook tightly onto the anechoic chamber material. The thin cylindrical portion of the metal rod is inserted into the bottom hole of the pointed rigid foam anechoic chamber material unit, with the diameter of the inserted cylinder smaller than the hole diameter (d2 < D). This prevents damage to the latter due to the significant difference in thermal expansion coefficients between the inserted metal cylinder and the pointed rigid foam anechoic chamber material unit during use. Two orthogonal, interpenetrating wire loading holes are used to radially disperse the wires on the metal rod, increasing the hooking force. The number of alternately orthogonally loaded wires is controlled between 2 and 6, with 1 to 3 wires in each loading hole. When more than 2 wires are loaded in each hole, the wires are arranged horizontally, and overlapping is not allowed. The radial dimension of the metal rod-shaped thin cylinder plus the steel wire is smaller than the bottom hole diameter of the pointed cone rigid foam anechoic chamber material unit (2×d1+d2<D, where d1 is the diameter of the steel wire, D is the diameter of the hole, and d2 is the diameter of the thin cylinder). Its function is to ensure the barbed force of the steel wire while avoiding the steel wire from damaging the anechoic chamber material during the insertion of the thin cylinder.

[0060] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0061] Example 1

[0062] In this embodiment, to mass-produce cone-shaped carbon foam anechoic chamber material units (square pyramids) with a bottom side length of 60mm × 60mm, a height of 100mm, and a weight of 0.108Kg, flat-bottomed internal threaded holes are first drilled at 60mm intervals on the aluminum alloy base plate. The hole depth is 5mm (H1), and the major diameter of the internal thread is 6mm (D). Then, a carbide drill bit is used to drill a hole centered at the bottom of each cone-shaped carbon foam anechoic chamber material unit. The hole diameter is 6mm (D), and the hole depth is 35mm (H2). A batch of stainless steel wires with a length of 24mm and a diameter of 0.5mm (d1) is shaped into a shape with a central arc and both ends turned outward at a 40° (α) angle. The length of the turned-out ends is 1.5mm. Aluminum alloy rods are selected to machine the aluminum alloy round rods for fixing the material units of the pointed carbon foam anechoic chamber. Each aluminum alloy rod is integrally machined into two parts: a screw rod (a threaded thick cylinder) and a thin cylinder. The screw rod has an external thread with a major diameter of 6mm (D) and a length of 5mm (H1). The thin cylinder has a diameter of 4.5mm (d2) and a length of 35mm (H2). The end of the thin cylinder is further machined into a conical end with a height of 2mm. Two orthogonal, intersecting loading holes with a diameter of 1mm are drilled 1mm from the bottom of the cone. All aluminum alloy round rods are vertically fastened to the aluminum alloy base plate with screws. Two stainless steel shaped wires are orthogonally hung in the two orthogonal loading holes of each aluminum alloy round rod. The stainless steel shaped wires are placed as symmetrically as possible on both sides of the thin cylinder, with the arc-shaped opening of each stainless steel shaped wire facing the direction of mounting the aluminum alloy base plate. Each conical carbon foam anechoic chamber material unit is inserted into the aluminum alloy round rod through its bottom hole, and the installation is completed when it is firmly attached to the aluminum alloy base plate.

[0063] In this embodiment, when the insertion process stops, the stainless steel shaped wire rebounds, allowing its end to be immediately and effectively embedded into the carbon foam hole, forming a barbed hook that tightens the pointed cone carbon foam anechoic chamber material unit, thus achieving its rapid and stable installation. Figures 1 to 7 This is a schematic diagram, used as supplementary explanation of the installation process in this embodiment.

[0064] Example 2

[0065] In this embodiment, to mass-produce cone-shaped silicon carbide foam anechoic chamber material units (square pyramids) with a bottom side length of 50mm × 50mm, a height of 70mm, and a weight of 0.08Kg, flat-bottomed internal threaded holes are first drilled at 50mm intervals on the carbon steel base plate. The hole depth is 4mm (H1), and the major diameter of the internal thread is 6mm (D). Then, a carbide drill bit is used to drill a hole centered at the bottom of each cone-shaped silicon carbide foam anechoic chamber material. The hole diameter is 6mm (D), and the hole depth is 25mm (H2). The batch of carbon steel wires with a length of 24mm and a diameter of 0.4mm (d1) are shaped into a shape with an arc in the middle and 45° (α) outward-curved ends. The length of the outward-curved ends is 1.5mm. Aluminum alloy rods are selected to machine the aluminum alloy round rods for fixing the pointed cone silicon carbide foam anechoic chamber material. Each aluminum alloy rod is integrally machined into two parts: a screw rod and a thin cylinder. The screw rod has a major diameter of 6mm (D) and a length of 4mm (H1), while the thin cylinder has a diameter of 5mm (d2) and a length of 25mm (H2). The end of the thin cylinder is further machined into a conical end with a height of 2mm. Two orthogonal, intersecting loading holes with a diameter of 1mm are drilled 0.5mm from the bottom of the cone. All aluminum alloy round rods are vertically fastened to the carbon steel base plate using screws. Two carbon steel shaped wires are orthogonally hung in the two orthogonal loading holes of each aluminum alloy round rod. The carbon steel shaped wires are placed as symmetrically as possible on both sides of the thin cylinder, with the arc-shaped opening of each carbon steel shaped wire facing the direction of mounting the carbon steel base plate. Each cone-shaped silicon carbide foam anechoic chamber material is inserted into the thin cylindrical part of the aluminum alloy rod through the bottom hole, and the assembly is completed when it is tightly attached to the carbon steel base plate.

[0066] In this embodiment, when the insertion process stops, the carbon steel shaped wire rebounds, allowing its end to immediately and effectively embed into the silicon carbide foam pores, forming barbs that hook the pointed cone silicon carbide foam anechoic chamber material, thus achieving rapid and stable installation. Figures 1 to 7 This is a schematic diagram, used as supplementary explanation of the installation process in this embodiment.

[0067] Example 3

[0068] In this embodiment, to mass-produce cone-shaped phenolic resin foam anechoic chamber material units (regular square pyramids) with a bottom side length of 200mm × 200mm, a height of 400mm, and a weight of 2.4Kg, flat-bottomed internal threaded holes are first drilled at 200mm intervals on a stainless steel base plate. The hole depth is 15mm (H1), and the major diameter of the internal thread is 20mm (D). Then, a carbide drill bit is used to drill a hole centered at the bottom of each cone-shaped phenolic resin foam anechoic chamber material. The hole diameter is 20mm (D), and the hole depth is 100mm (H2). A batch of stainless steel wires with a length of 70mm and a diameter of 1.5mm (d1) is shaped by applying pressure using a mold into a shape with a central arc and both ends turned outward at a 30° (α) angle. The length of the turned-out ends is 5mm. Stainless steel rods are selected to process the stainless steel round rods used to fix the pointed cone phenolic resin foam anechoic chamber material. Each stainless steel rod is integrally machined into two parts: a screw rod and a thin cylinder. The screw rod has an external thread with a major diameter of 20mm (D) and a length of 15mm (H1). The thin cylinder has a diameter of 16.5mm (d2) and a length of 100mm (H2). The end of the thin cylinder is further machined into a conical end with a height of 5mm. Two orthogonal, intersecting loading holes with a diameter of 5mm are drilled 3mm from the bottom of the cone. All stainless steel round rods are vertically fastened to the stainless steel base plate with screws. Six stainless steel shaped wires are alternately orthogonally hung in the two orthogonal loading holes of each stainless steel round rod. The stainless steel shaped wires are placed as symmetrically as possible on both sides of the thin cylinder, with the arc-shaped opening of each stainless steel shaped wire facing the direction of the stainless steel base plate. Each cone-shaped phenolic resin foam anechoic chamber material is inserted into the thin cylindrical part of a stainless steel rod through the bottom hole, and the installation is completed when it is firmly attached to the stainless steel base plate.

[0069] In this embodiment, when the insertion process stops, the stainless steel shaped wire rebounds, allowing its end to immediately and effectively embed into the pores of the phenolic resin foam, forming barbs that hook the pointed cone phenolic resin foam anechoic chamber material, thus achieving rapid and stable installation. Figures 1 to 7 This is a schematic diagram, used as supplementary explanation of the installation process in this embodiment.

[0070] Example 4

[0071] The difference from Example 3 is that a batch of cone-shaped cyanate ester resin foam anechoic chamber material units (square pyramids) with a bottom side length of 200mm×200mm, a height of 400mm, and a weight of 2.5Kg are installed.

[0072] In this embodiment, when the insertion process stops, the stainless steel shaped wire rebounds, allowing its end to immediately and effectively embed into the pores of the cyanate ester resin foam, forming barbs that hook the pointed cone cyanate ester resin foam anechoic chamber material, thus achieving rapid and stable installation. Figures 1 to 7 This is a schematic diagram, used as supplementary explanation of the installation process in this embodiment.

[0073] Example 5

[0074] The difference from Example 3 is that the conical polyimide resin foam anechoic chamber material units (square pyramids) with a bottom side length of 200mm×200mm, a height of 400mm, and a weight of 2.1Kg are installed in batches.

[0075] In this embodiment, when the insertion process stops, the stainless steel shaped wire rebounds, allowing its end to be immediately and effectively embedded into the polyimide resin foam pores, forming barbs that hook tightly around the pointed cone polyimide resin foam anechoic chamber material, thus achieving rapid and stable installation. Figures 1 to 7 This is a schematic diagram, used as supplementary explanation of the installation process in this embodiment.

[0076] Example 6

[0077] In this embodiment, to mass-produce conical carbon foam anechoic chamber material units (regular square pyramids) with a bottom side length of 80mm×80mm, a height of 180mm, and a weight of 0.38Kg, flat-bottomed internal threaded holes are first drilled at 80mm intervals on the carbon steel base plate. The hole depth is 8mm (H1), and the major diameter of the internal thread is 10mm (D). Then, a carbide drill bit is used to drill a hole centered at the bottom of each conical carbon foam anechoic chamber material unit. The hole diameter is 10mm (D), and the hole depth is 60mm (H2). The batch of carbon steel wires with a length of 52mm and a diameter of 0.8mm (d1) are shaped into a shape with an arc in the middle and 35° (α) outward-curved ends. The length of the outward-curved ends is 3mm. Aluminum alloy rods are selected to machine the aluminum alloy round rods for fixing the material units of the pointed carbon foam anechoic chamber. Each aluminum alloy rod is integrally machined into two parts: a screw rod and a thin cylinder. The screw rod has an external thread with a major diameter of 10mm (D) and a length of 8mm (H1). The thin cylinder has a diameter of 8mm (d2) and a length of 60mm (H2). The end of the thin cylinder is further machined into a conical end with a height of 3mm. Two orthogonal, intersecting loading holes with a diameter of 3mm are drilled 1.5mm from the bottom of the cone. All aluminum alloy round rods are vertically fastened to the carbon steel base plate with screws. Four carbon steel shaped wires are alternately orthogonally hung in the two orthogonal loading holes of each aluminum alloy round rod. The carbon steel shaped wires are placed as symmetrically as possible on both sides of the thin cylinder, with the arc-shaped opening of each carbon steel shaped wire facing the direction of mounting the carbon steel base plate. Each conical carbon foam anechoic chamber material unit is inserted into the thin cylindrical part of an aluminum alloy rod through a bottom hole, and the installation is completed when it is tightly attached to the carbon steel base plate.

[0078] In this embodiment, when the insertion process stops, the carbon steel shaped wire rebounds, allowing its end to be immediately and effectively embedded into the carbon foam hole, forming a barbed hook that tightens the pointed cone carbon foam anechoic chamber material unit, thus achieving its rapid and stable installation. Figures 1 to 7 This is a schematic diagram, used as supplementary explanation of the installation process in this embodiment.

[0079] Example 7

[0080] The difference from Example 6 is that a bronze rod is used to process the bronze round rod that fixes the pointed cone carbon foam anechoic chamber material unit.

[0081] In this embodiment, when the insertion process stops, the carbon steel shaped wire rebounds, allowing its end to be immediately and effectively embedded into the carbon foam hole, forming a barbed hook that tightens the pointed cone carbon foam anechoic chamber material unit, thus achieving its rapid and stable installation. Figures 1 to 7 This is a schematic diagram, used as supplementary explanation of the installation process in this embodiment.

[0082] Example 8

[0083] In this embodiment, to mass-produce cone-shaped silicon carbide foam anechoic chamber material units (square pyramids) with a bottom side length of 80mm×80mm, a height of 210mm, and a weight of 0.53Kg, flat-bottomed internal threaded holes are first drilled at 80mm intervals on the carbon steel base plate. The hole depth is 9mm (H1), and the major diameter of the internal thread is 10mm (D). Then, a carbide drill bit is used to drill a hole centered at the bottom of each cone-shaped silicon carbide foam anechoic chamber material. The hole diameter is 10mm (D), and the hole depth is 62mm (H2). A batch of stainless steel wires with a length of 52mm and a diameter of 1mm (d1) is shaped into a shape with a central arc and both ends turned outward at a 35° (α) angle. The length of the turned-out ends is 3mm. Carbon steel rods are selected to machine the carbon steel round rods for fixing the pointed cone silicon carbide foam anechoic chamber material. Each carbon steel rod is integrally machined into two parts: a screw rod and a thin cylinder. The screw rod has an external thread with a major diameter of 10mm (D) and a length of 9mm (H1). The thin cylinder has a diameter of 7.8mm (d2) and a length of 62mm (H2). The end of the thin cylinder is further machined into a conical end with a height of 3mm. Two orthogonal, intersecting loading holes with a diameter of 3mm are drilled 1.5mm from the bottom of the cone. All carbon steel round rods are vertically fastened to the carbon steel base plate with screws. Four stainless steel shaped wires are alternately orthogonally hung in the two orthogonal loading holes of each carbon steel round rod. The stainless steel shaped wires are placed as symmetrically as possible on both sides of the thin cylinder, with the arc-shaped opening of each stainless steel shaped wire facing the direction of the carbon steel base plate. Each cone-shaped silicon carbide foam anechoic chamber material is inserted into the thin cylindrical part of a carbon steel rod through the bottom hole, and the installation is completed when it is tightly attached to the carbon steel base plate.

[0084] In this embodiment, when the insertion process stops, the stainless steel shaped wire rebounds, allowing its end to immediately and effectively embed into the silicon carbide foam pores, forming barbs that hook tightly into the pointed cone silicon carbide foam anechoic chamber material, thus achieving rapid and stable installation. Figures 1 to 7 This is a schematic diagram, used as supplementary explanation of the installation process in this embodiment.

[0085] Example 9

[0086] In this embodiment, to mass-produce cone-shaped cyanate ester resin foam anechoic chamber material units (regular square pyramids) with a bottom side length of 120mm × 120mm, a height of 300mm, and a weight of 1.29Kg, flat-bottomed internal threaded holes are first drilled at 120mm intervals on the carbon steel base plate. The hole depth is 12mm (H1), and the major diameter of the internal thread is 14mm (D). Then, a carbide drill bit is used to drill a hole centered at the bottom of each cone-shaped phenolic resin foam anechoic chamber material. The hole diameter is 14mm (D), and the hole depth is 80mm (H2). A batch of stainless steel wires with a length of 56mm and a diameter of 1mm (d1) is shaped into a shape with a central arc and both ends turned outward at a 35° (α) angle. The length of the turned-out ends is 3mm. Stainless steel rods were selected to machine the stainless steel round rods used to fix the pointed cone cyanate ester resin foam anechoic chamber material. Each stainless steel rod was integrally machined into two parts: a screw rod and a thin cylinder. The screw rod part had an external thread with a major diameter of 14mm (D) and a length of 12mm (H1). The thin cylinder part had a diameter of 11.5mm (d2) and a length of 80mm (H2). The end of the thin cylinder was further machined into a conical end with a height of 4mm. Two orthogonal, intersecting loading holes with a diameter of 3.8mm were drilled 2mm from the bottom of the cone. All stainless steel round rods were vertically fastened to the carbon steel base plate with screws. Six stainless steel shaped wires were alternately orthogonally hung in the two orthogonal loading holes of each stainless steel round rod. The stainless steel shaped wires were placed as symmetrically as possible on both sides of the thin cylinder, with the arc-shaped opening of each stainless steel shaped wire facing the direction of the carbon steel base plate. Each cone-shaped cyanate ester foam anechoic chamber material is inserted into the bottom hole and fitted with the thin cylindrical part of the stainless steel rod. The installation is complete when the material is firmly attached to the carbon steel base plate.

[0087] In this embodiment, when the insertion process stops, the stainless steel shaped wire rebounds, allowing its end to immediately and effectively embed into the pores of the cyanate ester resin foam, forming barbs that hook the pointed cone cyanate ester resin foam anechoic chamber material, thus achieving rapid and stable installation. Figures 1 to 7 This is a schematic diagram, used as supplementary explanation of the installation process in this embodiment.

[0088] The results of implementation show that, in response to the technical challenges of installing rigid foam anechoic chamber materials with pointed cones suitable for extreme operating environments, this invention proposes a steel wire barb method: First, a hole is drilled in the center of the bottom of the rigid foam anechoic chamber material with a pointed cone structure. Then, one end of a metal rod is fixed to the base plate, and the other end is loaded with a molded steel wire, which is inserted into the hole at the bottom of the rigid foam anechoic chamber material. The steel wire entering the hole has a rebound effect, causing its end to embed into the rigid foam hole, forming a barb that hooks tightly, preventing the rigid foam anechoic chamber material from moving or rotating arbitrarily, thus achieving its rapid and stable installation.

Claims

1. A method for installing a rigid, cone-shaped foam anechoic chamber material suitable for extreme operating environments, characterized in that, The extreme operating environments are high temperature, ultra-low temperature, high vacuum, electric arc, strong particle radiation, or high-power antenna radiation. The steel wire barb method is adopted. First, a hole is drilled in the center of the bottom of the cone-shaped rigid foam anechoic chamber material unit. Then, one end of the metal rod is fixed to the base plate, and the other end of the metal rod is loaded with a molded steel wire, which is inserted into the hole at the bottom of the cone-shaped rigid foam anechoic chamber material unit. The steel wire entering the hole has a rebound effect, which makes the end of the metal rod embed into the rigid foam hole, forming a barb hook to tighten it, so that the cone-shaped rigid foam anechoic chamber material unit cannot move or rotate arbitrarily, thus achieving its rapid and stable installation. First, fix the metal rod to the base plate, and then use the wire hook method to tightly connect the pointed rigid foam anechoic chamber material unit to the metal rod. The specific installation process is as follows: (1) Drilling holes in the base plate Based on the installation concept of the pointed rigid foam anechoic chamber material unit with the top facing the electromagnetic wave and the bottom fixed to the base plate by steel wire hooks and metal rods, it is necessary to comprehensively consider the structural size and weight of the pointed rigid foam anechoic chamber material unit, design the number and size of the metal rods, and then determine the location distribution and size of the installation holes to be drilled on the base plate. The base plate is a metal plate, and the drilled holes are flat-bottomed internal thread holes. The major diameter D of the internal thread is required to be 4mm to 20mm, and the hole depth H1 is required to be 3mm to 15mm. (2) Drilling of the rigid foam anechoic chamber material unit with a pointed tip Based on the number and size design of the metal rods, a carbide drill bit is used to drill a hole in the center of the bottom of each cone-shaped rigid foam anechoic chamber material unit. The hole diameter is D, and the hole depth H2 is required to be 15mm to 100mm. The cone-shaped rigid foam anechoic chamber material unit used is a square pyramidal structure with a square base. It is made of silicon carbide-based foam anechoic chamber material, carbon-based foam anechoic chamber material, cyanate ester resin-based foam anechoic chamber material, polyimide resin-based foam anechoic chamber material, or phenolic resin-based foam anechoic chamber material. (3) Molding and shaping of steel wire The steel wire is 15mm to 70mm in length and d1 is 0.3mm to 2mm in diameter. First, the steel wire is shaped into an arc shape in the middle and the two ends are moderately turned outward by applying pressure through a mold. The outward turning angle α is required to be 30° to 45° and the length of the outward turning end is 1mm to 6mm. (4) Design and fabrication of metal round rods First, each metal rod is integrally machined into two cylindrical sections, one thick and one thin. The thick cylinder has a diameter of D and a length of H1. It is further machined into a screw rod with an external thread major diameter of D, which matches the internal thread on the base plate to form a screw thread. The thin cylinder has a diameter of d2 and a length of H2. The end of the thin cylinder is further machined into a conical end with a height of 2mm to 5mm, which matches the upper conical part of the bottom hole of the pointed cone rigid foam anechoic chamber material unit. Two loading holes are drilled radially in the thin cylinder for loading steel wire. The two loading holes are orthogonal and interpenetrating, and the diameter of each hole is 2 to 4 times the diameter of the steel wire d1. The center distance of the loading hole from the bottom of the cone is 0.5mm to 3mm, and it is as close as possible to the end of the thin cylinder. (5) Loading of shaped steel wire First, vertically fasten all the metal rods to the base plate with screws. Then, alternately pass the plastic steel wire through the two orthogonal loading holes of each metal rod. Place the plastic steel wires on both sides of the thin cylinder as symmetrically as possible, and make sure that the arc-shaped opening of the plastic steel wire faces the mounting base plate. (6) Insertion of rigid cone foam anechoic chamber material unit Each cone-shaped rigid foam anechoic chamber material unit is inserted into the metal rod with its bottom hole fitted into the thin cylindrical part. The insertion stops when the unit is pressed tightly against the base plate. The steel wire entering the hole has a rebound effect, causing its outward-curved end to embed into the foam hole, forming barbs that hook the anechoic chamber material, thus achieving rapid and stable installation of the cone-shaped rigid foam anechoic chamber material unit. The radial dimension of the metal rod thin cylinder plus the steel wire is smaller than the diameter of the bottom hole of the cone-shaped rigid foam anechoic chamber material unit: 2×d1+d2<D, where d1 is the diameter of the steel wire, D is the diameter of the hole, and d2 is the diameter of the thin cylinder.

2. The installation method of a cone-shaped rigid foam anechoic chamber material suitable for extreme use environments according to claim 1, characterized in that, The metal rods used are made of aluminum alloy, bronze, carbon steel, or stainless steel.

3. The installation method of a cone-shaped rigid foam anechoic chamber material suitable for extreme use environments according to claim 1, characterized in that, The steel wire used is made of carbon steel or stainless steel.

4. The installation method of a rigid cone-shaped foam anechoic chamber material suitable for extreme use environments according to claim 1, characterized in that, The steel wire is shaped by applying pressure with a mold. The arc design in the middle allows the steel wire to be symmetrically hung on both sides of the metal rod. The outward-turned design at both ends ensures that the ends of the steel wire are fully embedded in the foam holes when it rebounds, forming barbs that can hook the anechoic chamber material.

5. The installation method of a cone-shaped rigid foam anechoic chamber material suitable for extreme use environments according to claim 1, characterized in that, The thin cylindrical portion of the metal rod is inserted into the bottom hole of the pointed cone rigid foam anechoic chamber material unit, and the diameter d2 of the thin cylinder is smaller than the diameter D of the hole.

6. The installation method of a cone-shaped rigid foam anechoic chamber material suitable for extreme use environments according to claim 1, characterized in that, Two wire loading holes are designed to be orthogonal and interpenetrating, so that the wires are radially dispersed on the metal rod, increasing the barb force. The number of wires loaded alternately orthogonally is controlled between 2 and 6, and the number of wires in each loading hole is between 1 and 3. When the number of wires loaded in each loading hole exceeds 2, the wires are arranged sequentially in the horizontal direction.

Images