JPS6177596A - Missile radome and manufacture thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a radome for a flying object suitable for use in a flying object such as a rocket, and a method for manufacturing the same.

[Technical background of the invention and its problems] In general, this type of flying object radome is required to have high power transmittance and heat resistance that can withstand power heating for its imaging performance. There are inorganic and organic types. The former inorganic radome is made of brittle materials such as alumina and crystallized glass that have normal impact resistance but no established testing method for thermal shock resistance, and is molded using a hot press. Due to their large size, they are bulky, tend to crack during transportation, and are expensive.

On the other hand, the latter organic radome is usually E glass or S
fiber-reinforced plastics (FRP) made of unsaturated polyester, epoxy, phenol, etc. are used as a matrix based on lath and are processed using the S-M・C (Sheet Molding Compound) method and the B-M-C (Valve Molding Compound) method. A deformed material is made using a pressing method such as a roving method, and the fibers are impregnated with resin using a tape winding method or a wet method using cotton-like mats and net-like rovings to form the desired shape. This process completes the process to a predetermined dimensional accuracy. However, this organic radome has a gate content of about 20 to 30
%, and because it uses a mat, its strength is weak, and when applied to an object before rotation, it has a gap where a cavity and a relaxing surface run. On the other hand, for molding, the cylindrical part and tip part of the radome are made of long fibers and yil, respectively.
! There is also a method of forming the material using a river cloth, but in this method, there is a difference in the content of the river cloth between the cylindrical part and the tip, making it difficult to maintain uniformity. There was a problem in that the finished product was very sloppy and had poor productivity.

In addition, there are some products that improve heat resistance by using a heat-resistant resin material so that the radome can withstand heating caused by air friction called y-ca heating, but this requires a high molding temperature and e111! The problem was that it was very difficult to control the content and the manufacturing efficiency was very poor.

In this way, hot radomes are based on heat theory, and no organic radome has yet been developed that satisfies both product quality such as strength and heat resistance, and manufacturability. Improvements are strongly requested.

[Purpose of the Invention] This invention has been made in view of the above points, and provides a flying radome and a method for manufacturing the same, which can effectively improve the heat resistance and strength of the product, as well as improve the manufacturability. This is what we provide.

[Summary of the invention] That is, the flying object radome and its special selection method of the present invention are made of quartz fiber cloth and polyimide resin, and are made of quartz fiber cloth and polyimide resin. ! ! It is formed by laminating a number of prepregs in different directions, and includes the steps of forming the material, converting this material into prepreg, and laminating the prepreg material on the surface of the mandrel. forming a second layer on the outer periphery of the first layer, and forming a second layer by laminating the prepreg material in the same direction in a staggered manner substantially parallel to the outer periphery of the first layer; Wrap heat shrink tape, and then wrap glass cloth, mylar, and A on the outside.
This method is characterized by comprising a step of laminating L plates or glass cloth, and curing and molding the first and second layers using a bag molding method, and a step of mechanically cutting each of the layers.

[Embodiment of the Invention] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. The second is a radome manufactured by the method of the present invention, which is provided as a structure of the flying object at the same time as protecting a radar antenna device installed at the tip of the flying object (not shown).

This radome has a fiber diameter of about 10μ and a specific gravity of 2
．． 2.Strength: 70 to 9/mm2, elastic modulus: approximately 4. oooK
y/M2, quartz fiber cloth with Poisson's ratio of 017 and physical property value of bending strength of 11.5Kg/M at approximately 25℃
R2, about 10Kg/shoe2 at about 200℃, bending elastic modulus of about 3.7 at room temperature 9/1us2. Approximately 200"Ct' approx. 3.
It is manufactured using, for example, a triazine-based polyimide resin having an IKl/m 2 according to the following procedure.

That is, as shown in FIG. 2, in the first step, the quartz fiber cloth is sequentially subjected to degreasing treatment and silane coupling treatment, and then the monomer of the polyimide resin is applied to form a material.

This material has a gel time of about 170°C in the second step.
~60 seconds, resin content approximately 42-43%, cloth thickness approximately 0
．． The prepreg thickness is approximately 0.28 for 18 tram.
The prepreg is made into a tacky state as m.

Then, in a third step, this prepreg material is cut into triangular prepregs 19a corresponding to the inner shape of the radome, as shown in FIG. A cone-shaped mold 10 called a mandrel (see Fig. 4) is made to be placed at a predetermined angle (Fig. The first layer 11 is formed by laminating W4 (hereinafter referred to as different direction lamination) a plurality of sheets on the outer periphery as shown in FIG. Prepreg 19b is obtained by cutting the prepreg material into a rectangular shape as shown in FIG. 3(b).
For example, a plurality of sheets are laminated in a staggered manner substantially parallel to the axial direction of the mandrel 10 (hereinafter referred to as same-direction lamination), and the second i!12
form.

In the fifth step, a saturated polyester material having a shrinkage rate of about 20%, a tensile strength of about 8 to 9/2, a ratio of 1.4, and an elongation rate of about 200% is used. Prepare a heat-shrinkable tape 13 called shrinkage tape with a width of about 2 inches as shown, and use a needle or the like to ladle it with a 0.1 inch diameter.
A large number of through holes 14 for resin handling of φ are formed, and the heat shrink tape 13 is used to form the second 1! as shown in FIG.
! ! 12 is wrapped with a bandage from the bottom to the top, and glass cloth 15, Mylar 16. The Al plate 17 and the glass cloth 18 are laminated in a so-called layup. This is then hardened and molded using a bag molding method. That is, as shown in FIG. 7, there is a pressure cooker 2o called an autoclave for heating and pressurizing (illustrated by imaginary lines).
The outer periphery of the layer A laid up on the mandrel 10 is covered with a vacuum bag 21, and the ends are sealed with a clay material 22.

Next, a vacuum pump (not shown) is used to evacuate the bag 21 to about -1 Kl/m 2 through a vacuum pump ring 23 provided in a part of the bag 21 and a hose 24 connected thereto, and at the same time, the pressure cooker is heated. 20 is heated to 180°C and at the same time 4 kg/m is applied to the bag 21.
Pressure is applied for about 3 hours at about 2 degrees.

Next, as a sixth step, the second @
Only 12 is cut by a predetermined amount to finish the whole to a predetermined dimensional accuracy and formed into a desired radome.

According to one example compared with an existing radome, the characteristics of the dome obtained in this way are the same in terms of strength, Young's modulus, thermal conductivity, specific heat, and tanδ, as shown in the measurement data in the table below. Most areas have been improved except for some areas.

Therefore, the radome 2 manufactured as described above can be used as a structure of the flying object itself while protecting the radar antenna device provided at the tip of the flying object (not shown).

[Effects of the Invention] As detailed above, the present invention is characterized in that a plurality of prepregs made of quartz fiber cloth and polyimide resin are laminated in different directions and then cured to form a cone shape. The manufacturing method includes a first step of forming quartz fiber cloth and a polyimide resin material, a second step of forming the materials into prepregs, and a cone-shaped mandrel between the plurality of prepreg materials. a third step of laminating the prepreg material in different directions on the surface of the first layer to form a first layer; A fourth step of forming a laminated second layer, and laminating glass cloth Mylar, AJL board, glass cloth, etc. on the heat shrink tape having a plurality of through holes on the outer periphery of the second layer. The prepreg is manufactured through a fifth step using an autoclave in which the first and second layers are hardened and molded, and a sixth step in which each layer is cut with a cutting machine, so prepregs are laminated in different directions. Therefore, this layer is more uniform in terms of material, and since prepreg is used, the resin layer is sucked out by wrapping with heat shrink tape and cured using an autoclave method, rather than pressing with a wet method as in the conventional method. By completing the molding process, the volume content of quartz fiber cloth can be increased (according to actual measurement data, it is 55% of the conventional
(according to actual measurement data, the void ratio was increased from about 8% to 3%).
%).

Furthermore, according to the measured data in the above table, there is a considerable improvement in the strength retention rate of the radome (strength ratio at 25°C and 300°C).

Therefore, the strength and rigidity are improved, and at the same time, the uniformity is improved, and when used as a radome, there is less deterioration of antenna characteristics such as less beam deviation.

Furthermore, in terms of radio wave transmission properties, the dielectric loss tangent (ll!
Itan δ is usually 11I for this kind of radome! 4x10-
It can be made even smaller than 3, and the quality can be improved.

Furthermore, from the actual measurement data in the table above, the surrounding tir! J300
The strength and thermal conductivity at ℃ have hardly deteriorated compared to normal temperature IF (25℃).

Furthermore, the polyimide material used has been confirmed in rat tests to be less harmful than kerimide, which is known to be carcinogenic and addictive. In the special manufacturing process using the manufacturing method of the present invention, consideration can also be given to the safety of workers.

Furthermore, by separately laminating and forming the second layer, which is a cutting layer, on the first skin in the above-mentioned embodiment, cracks and cavities do not occur, and the factors that cause them can be eliminated. In addition, the effect of improving the accuracy of cutting can be achieved.

Furthermore, according to the manufacturing method of the present invention, the manufacturing method is a method of manufacturing using one mold called a mandrel, and the manufacturing method is a method of manufacturing using one mold called a mandrel, and it is a method of manufacturing using a single mold called a mandrel. The cost is reduced compared to traditional methods.

As mentioned above, it is possible to stabilize and improve quality such as strength, heat resistance, radio wave transparency, and safety, as well as reduce manufacturing costs. I can figure it out.

It should be noted that the present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

[Brief explanation of the drawing]

The drawings illustrate the present invention; FIG. 1 is a perspective view of a flying object radome, FIG. 2 is a diagram showing the manufacturing process of a flying object radome,
Figure 3 is a plan view of the prepreg, Figure 4 is a side view of the mandrel, Figure 5 is a diagram showing the heat-shrinkable tape, and Figure 6 (71 is a heat-shrinkable tape for stacking the prepreg on the outside of the mandrel) Figure 7 is a side view showing the state in which the heat-shrinkable tape in Figure 6 is wrapped with glass cloth, Mylar, temporary A, C, and glass cloth wrapped around the outer periphery of the heat-shrinkable tape in a bag molding method (two-way Figure 8 is a cross-sectional view showing the molding method, and Figure 9 is a partially enlarged cross-sectional view showing the P! This is an enlarged view of the state shown in Fig. 8 with the glass cloth, Mylar, A-M temporary, and glass cloth removed. It is a figure showing the filling method when laminating. 1... Radome, 10... Mandrel, 11...
1st decoy, 12...2nd attack, 13...heat) 17 shrink tape, 15.18...glass cloth, 16...mylar, 17...△1 provisional, 19a, 19b . . . Prepreg, 20 . Figure 2 Figure 1 Figure 7 Figure 97 Figure 10.

Claims (2)

[Claims] (1) A flying radome characterized by being formed into a cone shape by curing and laminating a plurality of prepregs made of quartz fiber cloth and polyimide resin in different directions. (2) A first step of forming a quartz fiber cloth and a polyimide resin material, a second step of converting the materials into prepregs, and applying the plurality of prepreg materials to the surface of a cone-shaped mandrel, respectively. a third step of laminating in the same direction in a staggered manner on the outer periphery of the first layer to form a second layer; A fourth step of
A heat shrinkable tape having a plurality of through holes is wrapped around the outer periphery of the second layer, and glass cloth, Mylar, etc.
It is characterized by comprising a fifth step of laminating Al plates or glass cloth and curing and molding the first and second layers using a bag molding method, and a sixth step of machining each of the layers. A method for manufacturing a flying object radome.