X-band large radar antenna cover unit element overlap structure and manufacturing method

Abstract

The present invention discloses a single-element overlap structure of a large-scale X-band radar antenna cover and a manufacturing method. The overlap structure is an aramid reinforced glass fiber reinforced high-density foam sandwich structure, including a gel coat layer, an outer skin layer, a foam core layer, and an inner skin layer, wherein the gel coat layer covers the outer surface of the outer skin layer, the foam core layer is located between the outer skin layer and the inner skin layer, and the inner skin layer and the outer skin layer are arranged symmetrically. The method sprays a gel coat layer on a mold, and then sequentially lays an outer skin layer, a foam core layer, and an inner skin layer, and uses a vacuum infusion process to introduce resin to obtain the overlap structure of the antenna cover single element. The overlap structure and manufacturing method use a glass fiber reinforced plastic foam sandwich as the antenna cover single element overlap structure, replacing the traditional glass fiber reinforced plastic solid overlap edge, thereby improving the electrical performance of the antenna cover and the tensile strength of the overlap edge without affecting the wave transmission performance, thereby ensuring the reliability of the single element overlap.

Description

Technical Field

[0001] The present invention relates to the technical field of radar antenna covers, and in particular to a single-element overlap structure of a large-scale X-band radar antenna cover and a manufacturing method thereof. Background Art

[0002] The radome is an electromagnetic window that protects the radar antenna from the influence of the natural environment. It can obtain the required electrical performance while maintaining the structure and bearing loads such as ice, snow, and wind, thereby improving the working environment and accuracy of the antenna. With the development of modern science and technology, the application demand for X-band and high-frequency radomes is increasing, which puts higher requirements on the development of radomes.

[0003] At present, most large radar radomes are made of single-element overlaps. The conventional radome fiberglass solid overlap connection form can only achieve a loss of 1dB in the X-band, which can no longer meet the current X-band radome's high wave transmission performance requirements. In order to optimize the connection form, the design, material selection, and processing technology of the radome must be optimized to ensure that it takes into account electrical performance, structural performance, and process performance. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a single-element overlap structure and a manufacturing method for a large X-band radar antenna cover. The overlap structure replaces the traditional fiberglass solid overlap edge connection form, improves the electrical performance of the antenna cover, and improves the tensile strength of the overlap structure without affecting the wave transmission performance. The method improves the bonding performance between the layers of the overlap structure through a vacuum infusion process and an inner and outer skin layer design, thereby ensuring the reliability of the single-element overlap.

[0005] In order to solve the above technical problems, the single-element overlapping structure of the X-band large radar antenna cover of the present invention includes a single-element body, an overlapping edge extending outside the single-element body, and the overlapping edge includes a gel coat layer, an outer skin layer, a foam core layer and an inner skin layer. The outer skin layer is laid on the outer surface of the foam core layer, the gel coat layer is laid on the surface of the outer skin layer, and the inner skin layer is laid on the inner surface of the foam core layer, and the inner skin layer and the outer skin layer are symmetrically arranged.

[0006] Furthermore, the gel coat layer is an unsaturated polyester resin and is coated on the surface of the outer skin layer to form a coating on the overlapped edge.

[0007] Furthermore, the outer skin layer comprises glass fiber cloth, aramid cloth and glass fiber cloth laid in sequence, and the gram weight per square meter of the glass fiber cloth and the aramid cloth ranges from 100 g / m 2 ~200g / m 2 .

[0008] Furthermore, the foam core layer is a high-density polyurethane foam with a density range of 100 kg / m3 ~150kg / m 3 .

[0009] Furthermore, the inner skin layer comprises glass fiber cloth, aramid cloth and glass fiber cloth laid in sequence, and the gram weight per square meter of the glass fiber cloth and the aramid cloth ranges from 100 g / m 2 ~200g / m 2 .

[0010] A method for manufacturing the above-mentioned X-band large radar antenna cover unit element overlap structure comprises the following steps: Step 1: Clean the molding surface of the mold, apply the release agent evenly, and let it dry for later use; Step 2: spray the gel coat layer on the molding surface of the mold and make it gel; Step 3: Lay the outer skin layer, foam core layer and inner skin layer on the gel coat layer of the mold forming surface in sequence, and flatten and compact each layer; Step 4: Lay the spiral tube on the periphery of the mold, lay the demoulding cloth, the guide net, the silicone ohm tube and the vacuum bag film on the surface of the inner skin layer in sequence, use the sealing strip to seal the vacuum bag film and the periphery of the mold, use the rubber inlet pipe to connect the silicone ohm tube, and close the pipe mouth of the rubber inlet pipe; Step 5: Connect the vacuum pipe at the vacuum interface of the mold to the vacuum pump, and turn on the vacuum pump to evacuate the air; Step 6: Keep the vacuum pump in normal operation, put the glue inlet pipe into the resin barrel, open the nozzle of the glue inlet pipe, and after the resin is poured in place, close the nozzle of the glue inlet pipe and stop feeding; Step 7: After the resin is completely cured, demoulding is performed to obtain a unit component overlap structure.

[0011] Furthermore, the resin is an unsaturated polyester resin with a viscosity ranging from 100 to 140 mPa•s. Since the X-band large radar antenna cover unit component overlap structure and manufacturing method of the present invention adopts the above technical scheme, that is, the overlap structure is an aramid reinforced glass fiber reinforced high-density foam sandwich structure, including a gel coat layer, an outer skin layer, a foam core layer, and an inner skin layer, wherein the gel coat layer covers the outer surface of the outer skin, the foam core layer is located between the outer skin layer and the inner skin layer, and the inner skin layer and the outer skin layer are arranged symmetrically. The method first sprays the gel coat layer on the mold, and then sequentially lays the outer skin layer, the foam core layer, and the inner skin layer, and adopts a vacuum infusion process to introduce resin to obtain the overlap structure of the antenna cover unit component. The overlap structure and manufacturing method adopts a fiberglass foam sandwich as the overlap structure of the radome unit element, replacing the traditional fiberglass solid overlap edge, thereby improving the electrical performance of the radome, and the whole cover loss can reach ≤0.5dB under the X-band; the inner and outer skin layers adopt aramid cloth to improve the tensile strength of the overlap edge of the fiberglass foam sandwich without affecting the wave transmission performance; in order to avoid the aramid-foam bulging delamination problem caused by poor resin impregnation of the aramid cloth, the inner and outer skin layers are designed to be glass fiber cloth, aramid cloth and glass fiber cloth in order, and the aramid cloth is separated from the foam core layer by glass fiber cloth to improve the bonding performance between the layers of the radome overlap edge and ensure the reliability of the unit element overlap. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments: Figure 1 It is a schematic diagram of the overlapping structure of the unit components of the X-band large radar antenna cover of the present invention. DETAILED DESCRIPTION

[0013] Implementation example Figure 1 As shown, the single-element overlapping structure of the X-band large radar antenna cover of the present invention includes a single-element body 5, an overlapping edge 51 extending outside the single-element body 5, and the overlapping edge 51 includes a gel coat layer 1, an outer skin layer 2, a foam core layer 3 and an inner skin layer 4. The outer surface of the foam core layer 3 is laid with the outer skin layer 2, the gel coat layer 1 is laid on the surface of the outer skin layer 2, and the inner skin layer 4 is laid on the inner surface of the foam core layer 3. The inner skin layer 4 and the outer skin layer 2 are arranged symmetrically.

[0014] Preferably, the gel coat layer 1 is an unsaturated polyester resin and is coated on the surface of the outer skin layer 2 to form a coating of the overlapping edge 51 .

[0015] Preferably, the outer skin layer 2 comprises glass fiber cloth, aramid cloth and glass fiber cloth laid in sequence, and the gram weight per square meter of the glass fiber cloth and the aramid cloth is in the range of 100g / m 2 ~200g / m 2 .

[0016] Preferably, the foam core layer 3 is high-density polyurethane foam with a density range of 100 kg / m3 ~150kg / m 3 .

[0017] Preferably, the inner skin layer 4 comprises glass fiber cloth, aramid cloth and glass fiber cloth laid in sequence, and the gram weight per square meter of the glass fiber cloth and the aramid cloth is in the range of 100g / m 2 ~200g / m 2 .

[0018] A method for manufacturing the above-mentioned X-band large radar antenna cover unit element overlap structure comprises the following steps: Step 1: Clean the molding surface of the mold, apply the release agent evenly, and let it dry for later use; Step 2: spray the gel coat layer on the molding surface of the mold and make it gel; Step 3: Lay the outer skin layer, foam core layer and inner skin layer on the gel coat layer of the mold forming surface in sequence, and flatten and compact each layer; Step 4: Lay the spiral tube on the periphery of the mold, lay the demoulding cloth, the guide net, the silicone ohm tube and the vacuum bag film on the surface of the inner skin layer in sequence, use the sealing strip to seal the vacuum bag film and the periphery of the mold, use the rubber inlet pipe to connect the silicone ohm tube, and close the pipe mouth of the rubber inlet pipe; Step 5: Connect the vacuum pipe at the vacuum interface of the mold to the vacuum pump, and turn on the vacuum pump to evacuate the air; Step 6: Keep the vacuum pump in normal operation, put the glue inlet pipe into the resin barrel, open the nozzle of the glue inlet pipe, and after the resin is poured in place, close the nozzle of the glue inlet pipe and stop feeding; Step 7: After the resin is completely cured, demoulding is performed to obtain a unit component overlap structure.

[0019] Preferably, the resin is an unsaturated polyester resin with a viscosity ranging from 100 to 140 mPa•s.

[0020] The lap joint structure and manufacturing method take into account the structural, electrical and process performances, and adopt a fiberglass foam interlayer as the lap joint structure of the antenna cover unit element to replace the traditional fiberglass solid lap edge, thereby improving the electrical performance of the antenna cover, and the whole cover loss can reach ≤0.5dB under the X-band; at the same time, aramid cloth is introduced to make the lap joint structure of the antenna cover unit element, which improves the tensile strength of the lap edge without affecting the wave transmission performance; in order to avoid the problem of aramid and foam bulging delamination caused by poor resin impregnation of aramid cloth, the inner and outer skin layer laying sequence is designed to be glass fiber cloth, aramid cloth, and glass fiber cloth, and the glass fiber cloth is used to isolate the aramid cloth from the core layer foam to improve the bonding performance between the layers of the lap edge of the antenna cover unit element, thereby ensuring the reliability of the unit element lap.

Claims

1. An X-band large radar antenna cover unit element overlap structure, comprising a unit element body, characterized in that: An overlapping edge extends outside the single component body, and the overlapping edge includes a gel coat layer, an outer skin layer, a foam core layer and an inner skin layer. The outer skin layer is laid on the outer surface of the foam core layer, the gel coat layer is laid on the surface of the outer skin layer, and the inner skin layer is laid on the inner surface of the foam core layer. The inner skin layer and the outer skin layer are symmetrically arranged.

2. The X-band large radar antenna cover unit component overlap structure according to claim 1, characterized in that: The gel coat layer is unsaturated polyester resin and is coated on the surface of the outer skin layer to form a coating of the overlapped edge.

3. The X-band large radar antenna cover unit component overlap structure according to claim 1 or 2, characterized in that: The outer skin layer includes glass fiber cloth, aramid cloth and glass fiber cloth laid in sequence, and the gram weight per square meter of the glass fiber cloth and aramid cloth ranges from 100g / m 2 ~200g / m 2 .

4. The X-band large radar antenna cover unit component overlap structure according to claim 3, characterized in that: The foam core layer is high-density polyurethane foam with a density range of 100kg / m 3 ~150kg / m 3 .

5. The X-band large radar antenna cover unit component overlap structure according to claim 3, characterized in that: The inner skin layer comprises glass fiber cloth, aramid cloth and glass fiber cloth laid in sequence, and the weight per square meter of the glass fiber cloth and aramid cloth ranges from 100g / m 2 ~200g / m 2 .

6. A method for manufacturing the X-band large radar antenna cover unit element overlap structure according to any one of claims 1 to 5, characterized in that The steps include: Step 1: Clean the molding surface of the mold, apply the release agent evenly, and let it dry for later use; Step 2: spray the gel coat layer on the molding surface of the mold and make it gel; Step 3: Lay the outer skin layer, foam core layer and inner skin layer on the gel coat layer of the mold forming surface in sequence, and flatten and compact each layer; Step 4: Lay the spiral tube on the periphery of the mold, lay the demoulding cloth, the guide net, the silicone ohm tube and the vacuum bag film on the surface of the inner skin layer in sequence, use the sealing strip to seal the vacuum bag film and the periphery of the mold, use the rubber inlet pipe to connect the silicone ohm tube, and close the pipe mouth of the rubber inlet pipe; Step 5: Connect the vacuum pipe at the vacuum interface of the mold to the vacuum pump, and turn on the vacuum pump to evacuate the air; Step 6: Keep the vacuum pump in normal operation, put the glue inlet pipe into the resin barrel, open the nozzle of the glue inlet pipe, and after the resin is poured in place, close the nozzle of the glue inlet pipe and stop feeding; Step 7: After the resin is completely cured, demoulding is performed to obtain a unit component overlap structure.

7. The method for manufacturing the X-band large radar antenna cover unit element overlap structure according to claim 6, characterized in that: The resin is an unsaturated polyester resin with a viscosity ranging from 100 to 140 mPa•s.

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