JP2016149756A - Radome for aviation body and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radome for an aviation body, light weight, having a sandwich structure of a three-dimensional shape, excellent in electromagnetic wave transmissivity and a manufacturing method of the same.SOLUTION: The radome for an aviation body has a shape of covering an electromagnetic wave instrument installed on an aviation body, and is formed with a sandwich panel structure in which a core material (30), compounded by foaming insulting reinforced fiber (31) and a heat-resistant resin (32), is held between skin materials (20), composed of a fiber-reinforced material formed by compounding a quartz cloth (21) and a heat-resistant resin (22).SELECTED DRAWING: Figure 1

Description

  The present invention relates to a flying object radome for protecting a radio wave device mounted on a flying object such as an aircraft from an external environment, and a method for manufacturing a flying object radome.

  Various types of antennas or radio wave devices such as radar are mounted on a flying object such as an aircraft. These radio wave devices are protected from the external environment by being covered with a radome. Such a radome is required not only to be durable enough to protect the radio wave device, but also to have a radio wave characteristic capable of sufficiently transmitting radio waves transmitted and received by the radio wave device.

  The specific configuration of the flying radome is not particularly limited. In recent years, however, aircraft have been required to be lighter from the viewpoint of improving fuel efficiency. Therefore, a lighter structure using fiber-reinforced plastic (FRP) is also used for the radome for the flying object.

  In general, such a radome may be a single FRP material having good radio wave transmission characteristics or a sandwich structure in which a core material (honeycomb core, foam core, etc.) is combined with the FRP material. That's it.

  For example, as a conventional technology, for a flying object in which a core is made of a polyetherimide foam material, and a face plate sandwiching both sides of the core is made of FRP of cyanate resin, it is configured as a single-layer or multiple-layer aspect sandwich structure There is a radome (see, for example, Patent Document 1).

  In addition, as another conventional technique, a main body having a shape covering a radio wave device mounted on a flying object, and an attachment part for attaching the corresponding main body part to the flying object, the main body part and the attachment part include A sandwich structure in which the surface of the core material is covered with a series of face plates, and the core material of the attachment portion is a composite structure made of a thermosetting resin composition reinforced with fibers, and the composite structure Some of the reinforcing resin layers constituting the body include a configuration in which a different type of resin layer from the face plate is included (see, for example, Patent Document 2).

  Furthermore, there is a conventional technique related to a sandwich structure in which a core made of a syntactic foam obtained by mixing an inorganic microballoon with a polyimide resin is sandwiched between two skin materials made of fiber reinforced polyimide resin (for example, (See Patent Document 3).

Japanese Patent No. 3572517 Japanese Patent No. 5320278 JP-A-7-1673

However, the prior art has the following problems.
In an aircraft flying at supersonic speed, the temperature of the outer surface of the radome is expected to be 300 ° C. or more due to aerodynamic heating during flight, although it depends on the flight speed, flight altitude and flight time. Further, when radio waves are transmitted during flight, heat is generated due to radio wave transmission loss. For this reason, the temperature of the radome may be further increased due to such transmission loss.

  A ceramic material is an example of a material having excellent radio wave permeability and high heat resistance. However, ceramic materials are heavy, vulnerable to impacts, brittle and easy to break, so they are not used for safety reasons in aircraft on which people ride.

  On the other hand, when using a composite material that is difficult to crack and has high toughness, polyimide resin is an example of FRP matrix resin that can be used under such high temperature conditions. However, when a foam material is formed by foaming polyimide resin, there is a problem that sufficient strength and rigidity as a core are difficult to obtain, and when the expansion ratio is lowered, the weight becomes heavier and radio wave permeability becomes lower. There were problems such as worsening.

  Furthermore, since the foam has an open cell structure (open void), the resin easily penetrates by adhesion to the skin material. For this reason, the resin is insufficient, the adhesiveness is poor, the integration is difficult, and it is difficult to realize the 3D integrated radome shape with the sandwich structure.

  The flying body radome in Patent Document 1 is configured by a single-layer or multiple-layer curved sandwich structure having a small curvature. Further, the core is made of a polyetherimide foam material, and the face plate sandwiching both sides of the core is made of FRP of cyanate resin. As described above, the flying radome in Patent Document 1 uses cyanate resin for the face plate on the surface of the sandwich structure. For this reason, at a temperature of 300 ° C. or higher, heat resistance is insufficient and long-term use is difficult.

  On the other hand, a core material obtained by foaming a polyimide resin that can be used under high temperature conditions is not suitable as a core material when the expansion ratio is increased and the specific gravity is decreased. On the other hand, a foamed core material having a reduced foaming ratio of polyimide resin increases strength and rigidity, but increases weight, and also decreases radio wave transmittance and increases dielectric loss. For this reason, it is difficult to achieve both improvement in strength and rigidity and prevention of deterioration in radio wave characteristics.

  In addition, the air radome in Patent Document 1 has low thermal conductivity, and cannot efficiently propagate heat generated by radio wave absorption loss at the time of radar output to the outside. For this reason, there existed a problem that temperature became high.

  Patent Document 2 discloses examples of various materials with respect to the face material and the core material having a sandwich structure. However, in any combination of materials, the radome material of an aircraft flying at supersonic speed has a problem that the light weight, strength / rigidity, radio wave characteristics, and heat resistance cannot be satisfied.

  Furthermore, Patent Document 3 discloses a sandwich material for a radome using a syntactic foam material as a core material. However, the core using the syntactic foam material is heavier than the honeycomb core like the foamed core material, and is inferior in terms of radio wave transmission and dielectric loss. Therefore, the structure in Patent Document 3 is not suitable as a radome material used for a supersonic flying body.

  The present invention has been made to solve the above-described problems, and provides a flying object radome having a three-dimensional sandwich structure that is lightweight and excellent in radio wave transmission, and a manufacturing method of the flying object radome. It is intended to provide.

A flying object radome according to the present invention is a flying object radome having a shape covering a radio wave device mounted on a flying object, and is a skin made of a fiber reinforced material in which a quartz cloth and a heat resistant resin are combined. It is formed by a sandwich panel structure in which a core material in which an electrically insulating reinforcing fiber and a heat resistant resin are foamed and combined is sandwiched between the materials.
It is.

  A method for manufacturing a flying object radome according to the present invention is a method for manufacturing a flying object radome formed by a sandwich panel structure in which a core material is sandwiched between skin materials, and is electrically insulated from reinforcing fibers. Impregnating wool made of continuous fibers of heat-resistant quartz and heat-resistant resin diluted with a solvent to provide tackiness, and impregnating quartz cloth with heat-resistant resin The prepreg sheet is laminated, and the core material manufactured in the first step is sandwiched between the second step for manufacturing the skin material by heating and curing using a mold, and the skin material manufactured in the second step. And a third step of manufacturing an integrated sandwich structure.

  According to the present invention, a radome for a flying body is configured by a sandwich structure by combining an FRP molded body with respect to a ceramic radome, and an unbreakable integral structure that is lightweight, excellent in strength and rigidity as a mechanical characteristic is realized. As an electrical characteristic, high radio wave permeability can be realized. As a result, it is possible to obtain a flying radome and a flying radome manufacturing method that has excellent radio wave permeability and structural strength, and has heat resistance capable of withstanding the temperature rise during use of supersonic aerodynamic heating and radar. it can.

It is sectional drawing which shows the sandwich structure of the radome in Embodiment 1 of this invention. It is an enlarged view of the partial cross section of the sandwich structure of the radome in Embodiment 1 of this invention. It is a flowchart regarding the manufacturing process of the radome in Embodiment 2 of this invention. It is explanatory drawing which showed the manufacturing procedure of the skin material for radomes in Embodiment 2 of this invention. It is explanatory drawing which showed the manufacturing procedure of the core material in Embodiment 2 of this invention. It is explanatory drawing which showed the manufacturing procedure which sandwiches the skin material and core material in Embodiment 2 of this invention.

  Hereinafter, preferred embodiments of a flying object radome and a flying object radome according to the present invention will be described with reference to the drawings.

Embodiment 1 FIG.
FIG. 1 is a cross-sectional view showing a sandwich structure of a radome according to Embodiment 1 of the present invention. The radome 10 according to the first embodiment includes skin materials 20 (1) and 20 (2) and a core material 30.

  FIG. 2 is an enlarged view of a partial cross section of the radome sandwich structure according to Embodiment 1 of the present invention. More specifically, the partial cross-sectional view shown in FIG. 2 corresponds to an enlarged view of “A part” in FIG.

  The core material 30 has a structure in which the portions where the reinforcing fibers 31 intersect with each other are joined by a polyimide resin 32. As described above, the core material 30 in the first embodiment is a low-density molded body including the reinforcing fibers 31 and the polyimide resin 32. The volume ratio of the reinforcing fibers 31 is preferably 3% to 10%, and the volume ratio of the resin is preferably 20% or less, and the core material 30 has an apparent bulk specific gravity of 0. It is a low-density molded product of 3 or less. In addition, in the core of a polyetherimide foam material, a bulk specific gravity of about 0.6 to 0.8 is normal, and if it is reduced to 0.3, the strength is insufficient and is not suitable for practical use.

  When the volume content ratio of the reinforcing fibers 31 is more than 10%, a large amount of the polyimide resin 32 necessary for fixing and molding the fibers is required. As a result, since the bulk specific gravity of the low density molded body exceeds 0.3, the core material 30 becomes heavy. Here, the radome structure needs to be manufactured with an optimum thickness in accordance with the frequency of the radio wave to be used. In this case, it is preferable that the specific gravity of the core material 30 is light in terms of radio wave transmission.

  On the contrary, when the volume content ratio of the reinforcing fibers 31 is less than 3%, the strength and rigidity as the core material 30 when combined with the polyimide resin 32 become insufficient, and the strength and rigidity of the same level as the foam core material are obtained. Therefore, it is not preferable as the core material 30 for sandwich structure.

  That is, when the volume content ratio of the reinforcing fiber 31 is more than 10% as the core material 30, the apparent density becomes larger than 0.3, and the core material 30 becomes heavy as the core material 30 of the sandwich panel. End up.

  If the density of the core material 30 is 0.3, strength and rigidity as a sandwich panel can be obtained. If a core with higher density is used, the core material itself has strength and rigidity as a fiber-reinforced composite material. Therefore, the reinforcing effect by the skin material 20 cannot be obtained, and the weight reduction cannot be realized, which is not preferable.

  On the other hand, when the volume content ratio of the reinforcing fibers 31 is smaller than 3%, the strength and rigidity as the core material 30 is lowered. As a result, strength and rigidity as a sandwich panel cannot be obtained, which is not preferable.

  Moreover, as a form of the reinforcing fiber 31 to be used, it is preferable to use an aggregate of short fibers having a length of 3 mm or more, or a continuous fiber. In both cases of short fibers and continuous fibers, they are processed into wool and used. In addition, if fibers with a length of 3 mm or more are used, a low-density molded body having a bulk specific gravity of 0.3 or less can be realized, and the strength and rigidity as the core material 30 for sandwich panels can be secured. It becomes.

  On the other hand, when fibers shorter than 3 mm in length are used, it becomes difficult to form an FRP molded product with a low specific gravity, and strength and rigidity are further reduced. That is, when the reinforcing fiber 31 having a length shorter than 3 mm is used, the specific gravity after molding of the core material 30 becomes larger than 0.3, and the strength and rigidity are further lowered, which is not preferable. Therefore, the fiber length as a short fiber is preferably 3 mm or more.

  A continuous fiber is a fiber obtained by spinning, but is not cut by post-processing, whereas a short fiber is cut by post-processing. Therefore, the short fibers have different length distributions depending on the processing method. What is cut and processed is called chopped fiber, and a few millimeters (3 mm, 6 to 25 mm is a common size. When processed by pulverization instead of cutting, it is called milled fiber, and the length is It is generally about 1 mm or less.

  The skin material 20 is an FRP molded body in which a quartz cloth and a polyimide resin are combined. The volume ratios of the skin material 20 are preferably 30% to 60% for the quartz cloth and 70% to 40% for the polyimide resin.

  When the volume ratio of the polyimide resin is more than 70%, the strength and rigidity of the FRP molded product cannot be obtained sufficiently, which is not preferable. Further, when the volume ratio of the polyimide resin is less than 40%, the adhesion of the quartz cloth is lowered, and as a result, the strength of the FRP molded body is lowered.

  The polyimide resin 32 used as the core material 30 in the present invention may be either a condensation type or an addition type as long as it is thermosetting. Also, the structure is not particularly limited as long as short fibers randomly oriented like cotton can be fixed and molded. Therefore, what is generally used as the polyimide resin 32 may be used, and two or more kinds of polyimide resins may be used as necessary.

  Specific examples of the polyimide resin 32 used as the core material 30 include, for example, Maruzen Petrochemical's BANI-M, BANI-X, I.I. S. T.A. SKYBOND, Pyre-ML, Ube Industries' PETI, U-varnish, Unitika's U imide, and the like.

  On the other hand, the polyimide resin 22 used for the skin material 20 may be either a condensation type or an addition type as long as it is thermosetting, but is particularly preferable if it can be cured and bonded to the core material 30. Specific examples of the polyimide resin 22 used as the skin material 20 include, for example, BANZ-M, BANI-X, I.I. S. T.A. SKYBOND, Pyre-ML, Ube Industries' PETI, U-varnish, Unitika's U imide, and the like.

  The polyimide resin 22 used for the skin material 20 and the polyimide resin 32 used for the core material 30 do not have any particular problem even if they are not the same.

  The skin material 20 and the core material 30 are advantageously joined by curing and joining the skin material 20 with the core material 30 in contact. However, the skin material 20 and the core material 30 may be separately molded, and both may be bonded using a heat-resistant adhesive. Specific examples of the heat-resistant adhesive include, for example, Maruzen Petrochemical's BANI-M, BANI-X, I.I. S. T.A. SKYBOND, Pyre-ML, Ube Industries' PETI, U-varnish, Unitika's U imide, and the like.

  The reinforcing fiber 31 is preferably one having a high specific strength, excellent heat resistance and insulation, and a low dielectric constant. Moreover, as a kind of glass fiber, there are E glass, S glass, NE glass, etc., and quartz fiber with high purity is most preferable.

  Examples of the quartz fiber include Shin-Etsu quartz Q glass and JSL AstroQuartz. Examples of the aramid fiber include Kevlar, Technora, Twaron, and the like.

  As the inorganic material, glass fiber is preferable, and as the organic material, aramid fiber is preferable. As the glass fiber, a high-purity quartz glass fiber is particularly preferable because of its high radio wave permeability and excellent dielectric loss.

  The cloth 21 used for the skin material 20 is preferably satin weave, which is easy to shift along the curved surface, and is more preferable than plain weave. Specifically, for example, SQF09AS-02 made of Shin-Etsu quartz can be used. .

  As described above, according to the first embodiment, the sandwich panel structure formed of the skin material made of the fiber reinforcing material in which the quartz cloth and the polyimide resin are combined and the core material made of the reinforcing fiber and the polyimide resin. As a radome is formed. As a result, it is possible to realize a radome having a three-dimensional sandwich structure that is light in weight and excellent in radio wave transmission, which is suitable for protecting a radio wave device mounted on a flying body such as an aircraft from the external environment.

Embodiment 2. FIG.
In the second embodiment, the manufacturing process of the radome of the present invention described in the first embodiment will be specifically described with reference to the drawings. FIG. 3 is a flowchart relating to a radome manufacturing process according to the second embodiment of the present invention.

The flowchart shown in FIG. 3 is roughly divided into the following four steps.
S10: A step of preparing reinforcing fibers used in the skin material 20 and the core material 30.
S20: This is a molding flow of the skin material 20, and is composed of four steps S21 to S24.
S30: A molding flow of the core material 30, which is composed of four steps S31 to S34.
S40: A flow for sandwiching the skin material 20 and the core material 30, and includes two steps S41 and S42.

  First, in step S10, respective reinforcing fibers (corresponding to the cloth 21 and the reinforcing fibers 31) used in the molding flow S20 of the skin material 20 and the molding flow S30 of the core material 30 are prepared. As the reinforcing fiber, Q glass of Shin-Etsu quartz was used. For the skin material 20, SQF09AS-02 woven into a cloth was used, while for the core material 30, quartz wool dispersed in a cotton shape was used.

  Next, steps S20, S30, and S40 will be described in detail with reference to FIGS. 4, 5, and 6, respectively. FIG. 4 is an explanatory view showing a manufacturing procedure of the radome skin material 20 according to the second embodiment of the present invention. Moreover, FIG. 5 is explanatory drawing which showed the manufacturing procedure of the core material 30 in Embodiment 2 of this invention. Furthermore, FIG. 6 is explanatory drawing which showed the manufacturing procedure which sandwiches the skin material 20 and the core material 30 in Embodiment 2 of this invention.

  Using the reinforcing fiber prepared in step S10, a cloth 21 (SQF09AS-02 of Shin-Etsu quartz) used for the skin materials 20 (1) and 20 (2) is prepared (corresponding to step S21), and the core material 30 is used. Wool 33 to be used is prepared (corresponding to step S31).

Next, molding of the skin material 20 will be described with reference to FIGS. 3 and 4.
In the fiber cloth forming step S21, the satin weaving that is easily misaligned was selected for the cloth 21 in consideration of formation on a three-dimensional curved surface. Note that the cross 21 weaving method may be twill weaving, plain weaving, or the like in addition to the satin weaving by forming the curved surface shape to be shaped with the amount of fiber driven.

  Next, in the prepreg forming step S22, the woven cloth 21 is impregnated with the polyimide resin 22 diluted with a solvent, and then the excess solvent is dried to obtain a prepreg sheet 23 formed into a prepreg. By adding microballoons to the solvent, the viscosity of the diluted resin can be adjusted, the amount of resin adhesion can be easily controlled, and the core material can be reduced in specific gravity and ensure strength and rigidity.

  At this time, it is desirable to adjust the adhesion amount of the polyimide resin 22 to the cloth 21 so that the weight ratio is in the range of 30% to 40%. When the adhesion amount of the polyimide resin 22 is less than 30%, the resin is insufficient at the time of thermosetting molding, and the fixation and adhesion of the fibers are deteriorated, which causes cracking and a decrease in strength, which is not preferable. On the other hand, when the adhesion amount of the polyimide resin 22 is more than 40%, the fiber filling ratio is lowered at the time of molding, and the strength and rigidity as a molded body are lowered.

  Next, in the shaping to the mold in step S23, the prepreg sheet 23 is laminated on the molding die 1 (1) having the inner shape of the radome and the molding die 1 (2) having the outer shape. Thus, the prepreg laminate 24 is obtained with a predetermined thickness.

  When laminating, it is possible to adopt a deep drawing method in which the texture of the prepreg sheet 23 is shifted and shaped into a 3D shape so that the prepreg sheet 23 conforms to the mold. Or you may employ | adopt the method of making the prepreg sheet | seat 23 cut | judged in the pattern of the expanded view which expand | deployed 3D curved surface to be laminated | stacked.

  In stacking, it is preferable to stack the next layers in order while shifting the positions so that the fiber orientation and discontinuous butting positions of the prepreg sheet 23 are evenly dispersed. The thickness of the skin material 20 for the sandwich panel is preferably in the range of about 0.2 mm to 2 mm.

  The thickness required for the sandwich material is determined by the band of radio waves used. Thereafter, the thickness of the skin material 20 necessary for securing the strength and rigidity as the sandwich material is determined by the strength calculation. In the normal use range, the skin thickness is preferably in the range of about 0.2 mm to 2 mm as described above from the balance between radio wave characteristics and strength and weight.

  Next, in the curing and molding that is Step S24, the laminated skin material 20 is bagged, and is heated and cured by an autoclave to be molded. In the heat curing step, the female mold 1 (3) (see FIG. 5) covering the outside may be set and molded using a press or an oven.

  The configuration of the molding die 1 and the heating / pressurizing method may be selected in accordance with the complexity of the shape to be molded, and it is not necessary to limit to autoclave molding.

  Through the series of processes in steps S21 to S24, the skin material 20 (2) for the front (outside) of the radome and the skin material 20 (1) for the inside can be respectively formed.

Next, molding of the core material 30 will be described with reference to FIGS. 3 and 5.
In preparation of the core material 30 in step S31, the core material 30 is prepared by first cutting a bundle of reinforcing fibers 31 into a length of 3 mm or more, removing the sizing agent adhering to the fibers by washing, and opening the fiber. The treatment is carried out to form a cotton. At this time, a cleaning solvent may be selected according to the type of sizing agent adhering to the fiber.

  Washing was performed by stirring the reinforcing fibers 31 in an aqueous solution mixed with a solvent that dissolves the sizing agent. When the fiber bundles were unwound and spread sufficiently after stirring, the aqueous solution was filtered and then dried to prepare the wool 33 for the core material 30.

  Next, in the impregnation in step S32, the matrix resin 34 diluted with a solvent is impregnated into the wool 33 to obtain a preform 35. In order to prevent the polyimide resin 32 from attaching too much to the wool 33, the dilution rate of the polyimide resin 32 is implemented as a preliminary test in advance, and the concentration of the polyimide resin 32 is adjusted before step S32. Went.

  As a result, as shown in FIG. 5, the polyimide resin 32 adheres in the vicinity where the fibers in the wool 33 intersect, and the bulk specific gravity after the polyimide resin 32 is dried and cured is 0.3 or less. The adhesion amount of the polyimide resin 32 was adjusted so that the fiber content was 3% to 10% by volume ratio.

  Next, in the shaping to the mold in step S33, the preform 35 is set between the male mold 1 (1) and the female mold 1 (3) of the radome mold 1 and pressed. The core material 30 is obtained by deforming, further heating the deformed preform 36, and performing curing molding. At this time, it is not necessary to heat until the polyimide resin 34 is completely cured. In the second embodiment, the heating is performed up to the B stage state (a state of semi-cured where there is no tack and is apparently cured).

  When completely cured, the core material 30 and the skin material 20 are not bonded and cannot be integrated in the sandwiching process with the skin material 20, which is the next process, and therefore an adhesive must be used. Therefore, it is desirable to form the skin material 20 and the core material 30 by heat treatment up to the B stage state. If the skin material 20 and the core material 30 that are processed up to the B stage state are used, bonding and integration are possible, and workability is improved.

Next, with reference to FIGS. 3 and 6, the sandwiching of the skin material 20 and the core material 30 will be described.
As shown in FIG. 6, the skin material 20 (1), 20 (2) and the core material 30 formed by the heat treatment up to the B-stage state in the setting of the mold in step S41 are used as a radome molding die. Set to 1 (1) and 1 (3).

  Then, in the curing and molding that is step S42, it is sufficiently heated and cured to obtain an integrated sandwich structure. At this time, the polyimide resin has a feature of generating a large amount of decomposition gas during curing, and foams in a space constrained by a mold. Due to this foaming behavior, the fibers of the core material are randomly dispersed, crosslinked and cured. As a result, the core material fibers and the polyimide resin are combined to obtain a core having low density and high strength and rigidity, that is, having tackiness, and a lightweight, high strength and high rigidity sandwich structure is obtained. .

  In the final integration step in step S40, the skin material 20 and the core material 30 do not need to be limited to the heat treatment up to the B stage state. For example, a completely cured skin material 20 and a core material 30 may be combined, or a B stage product and a fully cured product may be combined. In this case, an adhesive may be used between the skin material 20 and the core material 30 in order to ensure sufficient adhesive strength.

  The adhesive tends to flow when the viscosity is low, and adhesion failure is likely to occur. For this reason, it is preferable to use an adhesive adjusted to a high viscosity type. In order to adjust the viscosity, a microballoon or the like may be used.

  As already described as the problem to be solved by the present invention, in an aircraft flying at supersonic speed, the temperature of the outer surface of the radome is expected to be 300 ° C. or more due to aerodynamic heating during flight. In such an environment, examples of the FRP matrix resin that can be used as a composite material that is difficult to break and has high toughness include polyimide resins that are excellent in heat resistance.

  However, when polyimide resin is foamed into a core material, it is difficult to obtain sufficient strength and rigidity as a core, and there is a problem that if the expansion ratio is lowered, the weight becomes heavy and radio wave transmission properties deteriorate. .

  Furthermore, since the foam has an open-cell structure (open void), the resin easily penetrates by adhesion to the skin material. For this reason, the resin is insufficient, the adhesiveness is poor, the integration is difficult, and it is difficult to realize the 3D integrated radome shape with the sandwich structure.

  For such a problem, the manufacturing method according to the second embodiment uses a polyimide resin having excellent heat resistance for the core material and the skin material, and has excellent radio wave permeability and structural strength. A radome having a sandwich panel structure can be obtained using the reinforced reinforcing fiber as a core material. As a result, it is possible to realize a radome having excellent radio wave permeability and structural strength, and having heat resistance capable of withstanding supersonic aerodynamic heating and temperature rise when using a radar.

  In the first and second embodiments, the polyimide resin is used as the heat resistant resin, but the present invention is not limited to this. As a flying radome having a sandwich panel structure, other heat resistant resins can be used as long as heat resistance of 300 ° C. or higher (that is, glass transition temperature tg of 300 ° C. or higher) can be realized. is there.

  1 Radome mold (molding mold), 1 (1) male mold, 1 (2), 1 (3) female mold, 10 radome, 20, 20 (1), 20 (2) skin material, 21 cloth , 22 Polyimide resin (heat resistant resin), 23 prepreg sheet, 24 prepreg laminate, 30 core material, 31 reinforced fiber, 32 polyimide resin (heat resistant resin), 33 wool, 34 polyimide resin (heat resistant resin), 35 p Reform, 36 Pre-formed preform.

Claims (9)

A flying object radome having a shape covering a radio wave device mounted on the flying object,
Sandwich panel structure in which a core material made by combining insulating reinforcing fibers and heat-resistant resin is sandwiched between skin materials made of fiber-reinforced materials made of quartz cloth and heat-resistant resin. Aircraft radome formed by. The aircraft radome according to claim 1, wherein the heat-resistant resin used in the skin material and the core material is a polyimide resin. The aircraft radome according to claim 1 or 2, wherein the reinforcing fibers used for the skin material and the core material are quartz fibers. The flying body radome according to any one of claims 1 to 3, wherein the heat-resistant resin used for the skin material and the core material has a Tg of 300 ° C or higher. The aircraft radome according to any one of claims 1 to 4, wherein the core material has a fiber content of 3% to 10% and a bulk specific gravity of 0.3 or less. The flying radome according to any one of claims 1 to 5, wherein the reinforcing fibers used for the core material are short fibers of 3 mm or more, or continuous fibers. A method for manufacturing a flying radome formed by a sandwich panel structure in which a core material is sandwiched between skin materials,
A first step of producing the core material by impregnating a reinforcing fiber with wool composed of continuous fibers of insulating quartz and a heat-resistant resin diluted with a solvent to provide tackiness;
A second step of manufacturing the skin material by laminating a prepreg sheet impregnated with a heat-resistant resin in quartz cloth and heat-curing using a mold;
And a third step of manufacturing an integrated sandwich structure by sandwiching the core material manufactured in the first step with the skin material manufactured in the second step. The method for manufacturing a flying radome according to claim 7, wherein a polyimide resin is used as the heat resistant resin in the first step and the second step. The method for manufacturing a flying radome according to claim 7 or 8, wherein in the first step, the solvent is mixed and impregnated with a microballoon.

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