JPH098531A - Radome for antenna and its manufacture - Google Patents

Abstract

PURPOSE: To realize the radome for antenna that protects a parabolic antenna used for ground wave micro wave communication against rain or snow defect having a large diameter especially and a light weight with excellent radio wave transmission performance and durability and ease of manufacture and to realize its manufacture. CONSTITUTION: The radome is formed to be nearly an umbrella shaped body 2, an FRP-made flange 3 is formed to a circumferential ridge, a hollow double structure using front and rear FRP panels 9, 11 is adopted for the middle part, lots of fine supports 13,... support the front and rear FRP panels 9, 11 in a hollow part 12, and the fine supports 13,... are formed by impregnating and curing a packing material 6 to a fiber bundle 10D, and he ends of the fiber bundle 10D in the lengthwise direction are fixed in the front and rear FRP panels 9, 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radome for an antenna of a parabolic antenna for terrestrial microwave communication, and more particularly to a strong and lightweight antenna radome for transmitting electromagnetic waves well and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, parabolic antennas have been used for terrestrial microwave communication, but if rain or snow adheres or there is snow, the communication performance deteriorates, so a coating is necessary to prevent radio interference due to rain and snow. Becomes The roof may be simply covered, but in the case of fixing to a high tower, it is preferable to cover the antenna directly with a coating called a radome.

[0003]

Since a parabola antenna having a large diameter exceeding 2 m is used, a radome for a large antenna also needs to have a diameter exceeding 3 m. When such a radome is formed into a substantially cap-like body such as a net mesh cap, a synthetic resin material such as FRP is used.
In the case of a single plate of No. 3, if the wall thickness is 5 mm to 12 mm, there is a problem in the transmission of communication microwaves. If the FRP plate is made thin, there is a problem in terms of rigidity.
The rigidity can be improved by sandwiching a urethane resin or the like between two P plates, but there is a problem that the manufacturing process is complicated and the cost is high. In view of these circumstances, the present invention provides a radome for an antenna that satisfies the requirements of being able to transmit radio waves well, being lightweight, being excellent in rigidity and durability, being easy to manufacture and being light in cost. It was developed for the purpose of providing the manufacturing method.

[0004]

The present invention has taken the following technical means in order to solve the above problems and achieve the objects. That is,

(1) It is a substantially shaded structure, and F is formed at the peripheral edge.
The RP flange is formed, and the central part has a hollow double structure of front and back FRP plates.
The RP plates are connected and supported, and the thin struts are made by impregnating and curing a fiber bundle with a synthetic resin filler.
A radome for an antenna, which is connected to the fibers in the RP plate.

(2) It is a substantially shade-like structure, and is composed of a combination of several segmented bodies which are segmented by a plurality of radiations passing through the center of the circle, and the curved edge of each segmented body is a single FRP. A flange made of a plate, at the end of the isosceles side, a flange of the FRP for joining the divided bodies is projected on the concave curved surface side, and the central portion of each divided body has a hollow double structure of front and back FRP plates. A myriad of fine struts connect and support the front and back FRP plates, and the fine struts are obtained by impregnating and hardening the fiber bundle with the filler. The longitudinal ends of the fiber bundle are connected to the fibers in the front and back FRP plates. The radome for the antenna, which is characterized by being

(3) A step of forming a coating film layer on the concave mold surface of the mold forming the substantially shade-like structure, if necessary, and a step of forming a layer of a filler and fibers thereon. A step of forming fillers in a bundle of binding yarn fiber bundles of the double cloth to form upright cured thin struts; and a step of forming a flange with a laminate of the fibers and the filler outside the peripheral edge of the double cloth. , A method of manufacturing a radome for an antenna, which is characterized by comprising a combination with a step of forming a desired opening in the flange.

[0008]

The present invention constructed as described above has the following actions.

(1) Since the shape is a substantially cap-shaped structure such as a net mesh cap, rain and snow can be prevented by disposing the parabolic antenna above or in front of the parabola antenna. In addition, the wind-receiving area for the wind becomes smaller.

(2) Since the bolt hole is formed in the flange portion of the outer peripheral edge portion, it can be easily fixed to the fixed object through the support member.

(3) Since the central portion of the substantially cap-shaped structure has a double structure and is hollow, the front and back FRP plates are thin and allow easy transmission of radio waves, and the thin columns of the hollow part are thin and rough. Since the radio wave is transmitted by itself, the loss of radio wave transmission is smaller than that of the FRP filled with the same thickness.

(4) The thin struts are made by impregnating a fiber bundle having a length of 3 to 10 mm with a synthetic resin filler and hardening the bundle.
For example, since it is arranged innumerably at fixed intervals of 2 to 10 mm, it has excellent longitudinal compressive strength, and since the front and back FRP plates are integrally connected and supported by the thin columns, rigidity strength is high. Moreover, since the weight is lighter than the external volume, the strength of the support material can be reduced even when installed in a high place.

(5) A substantially cap-shaped structure composed of a combination of a plurality of partition bodies can be easily made into a large one having an overall diameter of 3 to 4 m, etc., and the concave-side joining flange is the same. Increase strength.

[0014]

An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a partially longitudinal side view showing a first embodiment of an antenna radome 1. The antenna radome 1 is, for example, a circular shape having a plane diameter of 50 to 300 cm, and is formed in a substantially conical shape with a raised central portion and a side surface in a substantially shaded shape such as a net-shaped hat. The substantially cap-shaped structure 2 has a flange 3 formed on the peripheral edge portion, and the central portion is a hollow double portion 4 formed by front and back FRP plates 9 and 11.
Are formed. As shown in detail in FIG. 2, the flange 3 is provided with a coating film layer 5 made of a synthetic resin material on the convex side, and a filler 6 and a fiber for reinforcing strength (inorganic, organic,
It is formed as an FRP plate body by stacking with a whisker 7). Further, bolt holes 8 are formed in the flange 3 at predetermined intervals. As shown in FIG. 2, the hollow double portion 4 has a coating film layer 5 continuous with the coating film layer 5 of the flange 3 formed on the convex side of the front plate 9 as required,
The filler 6, the fibers 7, and the woven fabric 10 are laminated to form an FRP plate, and the back plate 11 includes the filler 6, the fibers 7, and the woven fabric 10.
Is formed as a FRP plate by stacking with the above, and the inside is configured as a hollow portion 12. The hollow portion 12 has front and back plates 9,
Innumerable thin struts 13 ... Which are selected between 3 mm and 10 mm in length orthogonal to 11 are arranged.
3 ... is a binding thread 10D connected to the front and back woven fabrics 10,10
The filler 6 is impregnated and cured in the fiber bundle of 1. At the boundary between the hollow double portion 4 and the flange 3, the front and back plates 9, 11 are gradually thickened toward the outside to form a thick portion 14. As shown in FIG. 3, a drainage hole 15 penetrating in and out is formed in the thick portion 14, and when the antenna radome 1 is arranged so as to cover the front surface of the antenna, rainwater entering the concave side is lowered. The inner surface of the hole is covered with a protective material 15A. Radome for antenna 1 with this configuration
Is 50 to 200 cm in diameter, the thickness of the flange 3 and the hollow double portion is, for example, 5 to 15 mm, and is appropriately selected according to the required strength according to the size. As the fiber used for FRP (fiber reinforced plastic), metal, glass, carbon or the like is selected from inorganic type, organic type and whiskers, but glass is selected in consideration of cost and performance balance. As the woven cloth 10, for example, as shown in FIG. 4, both front and back sides have a flat design, and when weaving as a double weave in which a binding thread is interposed, a plain weave is formed by an upper warp thread 10A and a weft thread 10C, and a lower warp thread 1
0B and wefts 10C are plain weaved, the binding yarns 10D are moved up and down every several wefts 10C, and are arranged every several warps (for example, every 5 mm of wefts).
Further, in the case of not using this weaving, the binding yarn 10D can be inserted into the upper and lower two cloths for planting. Further, fiber fluff (tufted) may be stabbed into a flat cloth, and the woven cloth may be arranged with the fluff facing each other. When the woven cloth 10 is impregnated with the filler, the woven cloth 10, 10 is impregnated with the filler as in the right end portion in FIG.
Due to the capillary phenomenon, the filling material 6 is attached to 0D so that the upper and lower portions become thicker. The material of the woven cloth 10 is selected from, for example, glass fiber, synthetic resin fiber, carbon fiber, metal fiber and the like according to the application.

FIG. 5 is a rear view (concave surface) of the antenna radome 1 showing the second embodiment. In this embodiment, the same members as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted. The antenna radome 1 is divided into four sections 2A with two radiations L, L passing through the center P of the substantially shaded structure 2 as boundaries.
... are classified. Each segment 2A ... Has a substantially fan-shaped flat surface composed of isosceles and an arc curved edge, and the same flange 3 as the flange 3 of the first embodiment is formed by FRP on the arc curved edge. Further, flanges 16 of FRP are provided so as to project toward the concave surface at the ends of the isosceles side of each segment 2A.
Bolt holes 17 are opened along the length at predetermined intervals, and the flanges 16 and 16 of the two adjacent segment bodies 2A are joined to each other so that they can be joined by the bolts 18 or an adhesive. . That is, FIG. 6 is a side view showing a state in which one of the partition bodies 2A in FIG. 5 is removed, and FIG. 7 shows the flange 16 portion. The difference from the first embodiment is the flange 16
Therefore, the other parts are substantially the same because they are formed by a plurality of partition bodies 2A.

FIG. 8 is a schematic view showing the manufacturing process. Formwork 1
The coating film layer 5 is formed on the concave surface 20 of 9 as required.
After the coating film layer 5 is cured, a laminate of a filler 6 such as a thermosetting synthetic resin and a fiber 7 is formed on the surface of the coating film layer 5 to have a thickness of 1 to 3 mm, and the thick portion 14 is designed according to the design. Make it thick. After that, a woven cloth 10 as shown in FIG. 4 is disposed on the surface, and when the filler 6 is filled, the filler 6 adhered to the lower woven cloth 10 is included in the binding yarn 10D by a capillary phenomenon. The thin struts 13 are formed in a state in which the filler 6 is attached to the upper woven fabric 10 and is attached to the upper woven fabric 10 and is integrally joined to the lower laminated body. Then, a stack of the filler 6 and the fiber 7 is formed thereon, and the thickness is increased according to the design in the thick portion 14, and the filler 6 and the fiber 7 are formed in the flange 16 until the set flange thickness is reached. Stack up. The filler 7 is a honey-like gel, and when it is impregnated into a cloth, it is impregnated substantially uniformly by a capillary phenomenon, and in the binding yarn 10D, since it is orthogonal to the woven fabric 10 surface, the lower part of the binding yarn 10D is caused by surface tension. Since the filler 7 is impregnated in the warp and the upper part is hardened in a relatively short time, the thin strut 13 in which the filler 6 is impregnated in the binding yarn 10D has a hollow portion between the front and back FRP plates 9 and 11. And the front and back FRP plates 9 and 11 are firmly supported and connected.

The present invention is not limited to the above embodiment. When a fluff-fluffed cloth is laid instead of the double woven cloth and a filler is impregnated, the fluffed fluff becomes a thin strut, so that a normal cloth or a flocked cloth may be faced downward on this. The resulting filling of the filling material can also serve the same purpose. Further, the outer shape is not a cap shape but can be a substantially hemispherical shape or a flat plate shape.
Therefore, a substantially hemispherical shape or a flat plate shape is also included in the range of design change of the substantially cap-shaped structure.

[0018]

The present invention constructed as described above has the following excellent effects.

(1) Since the side surface is formed in a substantially shaded shape,
An effect that can be attached to the front of the parabolic antenna so as to cover it and sufficiently cover the primary radiator, and can protect the radiator and the parabolic reflector from rain and snow,
In addition, there is an effect that the wind receiving area for the wind is reduced and the antenna supporting tower can be simplified.

(2) Since the peripheral portion of the substantially cap-shaped structure is a plate body of FRP and has bolt holes, the parabolic surface is fixed to the parabolic antenna backside support of the parabolic antenna. Since the reflector can be completely covered and the central part is formed in a hollow double structure, the front and back plates are F
Even the RP plate itself can be a thin plate and is radio wave permeable, and the thin stanchions in the hollow part are the binding yarn fibers of the woven fabric and the synthetic resin filler included. Since it has radio wave permeability and is sparsely arranged and has a lot of space, it has an effect of minimizing the loss when the radio wave is transmitted.

(3) Since the substantially cap-shaped structure is a hollow double structure, the weight can be reduced to one third or less, and even if it is directly attached to the parabolic antenna, the steel tower for supporting it can be simplified. The effect of reducing the burden of maintaining the strength of the support material is also effective.

(4) In the case where the substantially cap-shaped structure is composed of partition bodies, it is easy to make a mold for making a large diameter one, and the uniformity of the wall thickness is improved. Since the flanges are formed on the equal side edges, the rigidity after assembly is guaranteed.

[Brief description of drawings]

FIG. 1 is a side view of a radome for an antenna.

FIG. 2 is a vertical cross-sectional side view of a main part of a substantially cap-shaped structure.

FIG. 3 is a vertical cross-sectional side view of a main part of the substantially cap-shaped structure.

FIG. 4 is a cross-sectional view showing the relationship between the double cloth and the thin columns.

FIG. 5 is a rear view of a radome for an antenna showing a second embodiment.

FIG. 6 is a side view of a radome for an antenna.

FIG. 7 is a cross-sectional view of a substantially cap-shaped structure showing a flange portion.

FIG. 8 is a partial cross-sectional view of a mold showing a manufacturing process of the antenna radome.

[Explanation of symbols]

 1 Radome for Antenna 2 Approximately Shaft-Shaped Constituent 2A Partition 3 Flange 4 Hollow Double Part 5 Coating Film Layer 6 Filler 7 Fiber 8 Bolt Hole 9 Table FRP Plate 10 Woven Fabric 10A Upper Warp 10B Lower Warp 10C Weft 10D Bonding Thread 11 Back FRP plate 12 Hollow part 13 Thin post 14 Thick part 15 Drain hole 16 Flange 17 Bolt hole 18 Bolt 19 Form frame 20 Concave surface

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasuo Nakajima 511 Mekata, Shimodate-shi, Ibaraki Taiei Shoko Co., Ltd. (72) Inventor Yasushi Kaneko 3-50, Ueishihara, Chofu-shi, Tokyo 1 Ann Within Ten Co., Ltd.

Claims (3)

[Claims] 1. A substantially cap-shaped structure having an FRP at a peripheral edge portion.
Of the front and back FRP plates are formed in the center, and innumerable thin columns are used for the front and back FRP plates.
The plates are connected and supported, and the thin struts are made by impregnating and hardening a fiber bundle with a synthetic resin filler. Both longitudinal ends of the fiber bundle are front and back FRP.
A radome for an antenna, which is connected to the fibers in the board. 2. A substantially cap-shaped structure, which is composed of a combination of several partition bodies divided by a plurality of radiations passing through the center thereof, and the curved edge of each partition body is made of a single plate of FRP. The flange of the FRP is formed on the isosceles side end so as to project toward the concave surface on the concave side, and the central part of each partition is made of a hollow double structure with front and back FRP plates. Innumerable thin columns connect and support the front and back FRP plates in the hollow part,
The thin strut is a fiber bundle in which a synthetic resin filler is impregnated and hardened, and both longitudinal ends of the fiber bundle are connected to the fibers in the front and back FRP plates. 3. A step of forming a coating film layer on the concave mold surface of the mold forming the substantially shade-like structure, if necessary, and laying a double cloth of fibers on it and filling it with a filling material. A step of impregnating the binding material in the fiber bundle of the heavy cloth with the filler and hardening it upright, a step of forming a flange by laminating the filler and the fiber outside the peripheral edge of the double cloth, and at a predetermined interval on the flange. A method of manufacturing a radome for an antenna, characterized by comprising the step of forming a bolt hole in a hole.