JPS6035287Y2 - Membrane material for radome - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a rubberized cloth structure used as a membrane material for a radome.

A radome is used to protect a radar antenna from wind, rain, snow, etc. As shown in FIG. 1, a radome 1 is assembled into a hemispherical shape by combining a plurality of panels 2.

As shown in FIG. 2, this panel is constructed by using a metal frame 3 as a strength member and a membrane material 4 stretched between them.

Generally, the following properties are required for this radome membrane material.

(1) Good radio wave transparency.

(Both dielectric constant and dielectric loss tangent values are small.

) (2) High tensile strength and modulus, low creep and elongation.

(3) It must have characteristics (weather resistance, color stability) that can withstand long-term outdoor use (more than one cape).

(4) It must be easy to adhere to a metal frame, have high strength, and have long-term reliability.

Lately, rubberized cloth type membrane materials have been used as this membrane material.

This rubber-coated fabric for membrane materials (hereinafter referred to as membrane material) has good radio wave permeability, high strength, low elongation, and other properties.The rubberized fabric (for example, a woven fabric made of aramid fiber) has good weather resistance. It is coated with a rubber composition (e.g. evaporated ethylene propylene rubber, chlorosulfonated polyethylene).

In particular, this coating rubber layer not only serves as a cover to prevent UV deterioration of the base fabric, but also serves as an intermediate material to improve waterproofing and adhesion with metal frames, and also plays a role in preventing abrasion and deterioration caused by dirt, dust, fine stones, etc. ing.

In this case, the life of this membrane material is inversely proportional to the amount of wear, that is,
It is proportional to the thickness of the coating rubber layer on the outside of the radome.

Therefore, to extend the service life, it is necessary to improve the wear resistance of the rubber layer or increase its thickness.

However, in order to improve the abrasion resistance of the rubber composition, it is necessary to add a large amount of reinforcing agent, which leads to a decrease in radio wave transmittance.

Furthermore, increasing the thickness of the rubber layer not only lowers the radio wave transmittance but also has the major disadvantage of increasing the weight and cost of the product.

This idea aims to provide a membrane material for a radome that has good radio wave transparency and weather resistance to eliminate these drawbacks, and the thickness ratio of the inner coating layer and the outer coating layer of the radome is set to 4. ~1:6~9.

This idea will be specifically explained below using an example.

FIG. 3 is a partially enlarged cross-sectional view showing the bonded state of the metal frame 3 and membrane material 4 of the panel 2, in which 5 is a base fabric (woven fabric made of aramid fibers), 6 is a coating rubber layer (chlorosulfonated polyethylene 7 is a special adhesive for bonding the metal frame and the membrane material 4.

Further, FIG. 4 shows a conventional membrane material structure, and FIG. 5 shows a membrane material structure of the present invention.

Reference numeral 6' indicates a coating rubber layer on the outside of the radome according to the present invention, and 6' indicates a coating rubber layer on the inside.

As shown in FIG. 4, in the conventional membrane material, both sides of the coating rubber layer have the same thickness.

However, since the coating rubber layer on the inside of the radome is not directly exposed to ultraviolet rays, wind, rain, dust, etc., it is important to ensure that the rubber layer is thick enough to serve as an intermediate layer to improve adhesion with the metal frame. good.

Therefore, the present invention has a structure in which the extra thickness of the inner rubber layer is exposed on the front side as shown in FIG.

In this case, it is necessary to set the thickness ratio inside:outside = 4 to 1:6 to 9.
% or less), the thickness of the rubber layer will be thinner, so in order to ensure the required bottom thickness of the inner rubber layer, the thickness ratio should not be too large, and even if there is some margin, the thickness ratio should not exceed this range. If this is done, the vulcanization degree will be unbalanced during the vulcanization process during the production of the membrane material.
This range was determined.

The membrane material of the present invention having such a configuration can extend the service life without changing the overall thickness, and eliminates the drawbacks that conventionally occur due to increased thickness, such as a decrease in radio wave transparency.
There is no increase in weight or product cost.

[Brief explanation of drawings]

Figure 1 is an outline drawing of a radome consisting of a panel joint structure;
Fig. 2 is a perspective view of the panel constituting this radome, Fig. 3 is a partially enlarged sectional view of the adhesive joint between the metal frame of the panel and the membrane material, and Fig. 4 is a structural diagram of the conventional membrane material. , 5th
The figure is a structural diagram of the membrane material according to the present invention. In the figure, 1 is a radome, 2 is a panel, 3 is a metal frame,
4 is a membrane material, 5 is a base fabric, 6 is a coating rubber layer, especially 6' is a coating rubber layer that is the outside of the radome according to the present invention, 6'' is the same < the coating rubber layer that is the inside, and 7 is a special It is an adhesive.

Claims (1)

[Scope of utility model registration request] In a film material for a radome formed by coating both sides of a reinforcing cloth with a rubber composition, the thickness ratio of the inner coating layer of the radome and the outer coating layer is 4 to 1:6 to
9. A membrane material for a radome, characterized by: