JPH09312491A - Electric wave absorber and installation thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to firmly adhere an absorber on a ceiling or on a side wall of an electric wave dark room by forming, in an ashesive face, a groove 21 or recessed section to put an adhesive in and making the shape of the groove 21 or recessed section in such a one as to engage with the hardened adhesive. SOLUTION: On an adhesive face of a block-like electric wave absorber 10 which is made of foamed resin material in which conductive powder is mixed, a groove 21 or recessed section to put an adhesive in is formed. The shape of the groove 21 or recessed section is made in such a one as to engate with the hardened adhesive. For example, the groove 21 which has a wedge-like cross section is formed in the adhesive face of a base 11 of the electric wave absorber 10 which is constituted of a projecting section and the base 11. The groove 21 can be formed by die molding or cutting after die molding or burying a resin material having a desired groove at the time of die molding. The groove 21 is formed in the longitudinal direction, in the width direction, or in other directions.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a block-shaped electromagnetic wave absorber made of a foamed resin material such as expanded polystyrene, expanded polyethylene, expanded phenol or expanded urethane used in an anechoic chamber and a method for mounting the same, and more particularly to a ceiling. TECHNICAL FIELD The present invention relates to a radio wave absorber that can be reliably and firmly attached to a wall, a side wall, and the like, and a method for attaching the same.

[0002]

2. Description of the Related Art Conventionally, a block-shaped electromagnetic wave absorber made of a foamed resin material such as foamed polystyrene, foamed polyethylene, foamed phenol or foamed urethane has been used for the ceiling and side walls of an anechoic chamber. It was fixed using an adhesive.

This electromagnetic wave absorber has, for example, a portion 12 having a pyramid-shaped or zigzag-shaped protrusion (hereinafter referred to as a protrusion) and a flat surface bonded to a ceiling, a side wall, or the like, as shown in FIG. Portion having (hereinafter, referred to as base material portion)
It is fixed by applying the adhesive 30 to the adhesive surface of the base material portion 11 and adhering it to the ceiling, the side wall, or the like.

However, the block-shaped radio wave absorber 10 made of a foamed resin material such as foamed polystyrene, foamed polyethylene, foamed phenol, or foamed urethane contains a conductive resin powder such as carbon black or graphite. It was difficult to firmly attach it to the ceiling, side wall, etc. because the mutual bonding force and the adhesive strength with the adhesive were weak.

That is, as shown in FIG. 15 (b) (AA 'cross section of FIG. 15 (a) when the radio wave absorber 10 is adhered to a ceiling, a side wall, etc.), the conductive powder 10b is contained in the foamed resin material 10a. However, since the foamed resin materials 10a are weakly bonded to each other and the conductive powder 10b is exposed on the adhesive surface of the base material portion 11, the adhesive strength with the adhesive 30 is weak.

Therefore, when the radio wave absorber is attached to the ceiling or the side wall 40, the radio wave absorber 10 may peel off.

Therefore, it is an object of the present invention to provide an electromagnetic wave absorber that can be firmly attached to the ceiling or side wall of an anechoic chamber and a method of attaching the same.

[0008]

A radio wave absorber according to claim 1 is a block-shaped radio wave absorber made of a foamed resin material mixed with a conductor powder, for filling an adhesive surface with an adhesive. The present invention is characterized in that it has a groove portion or a concave portion, and the shape of the groove portion or the concave portion is a shape that meshes with the filled and solidified adhesive.

A radio wave absorber according to a second aspect of the present invention is the radio wave absorber according to the first aspect, characterized in that the groove or the recess is formed by a member embedded at the time of molding. .

A radio wave absorber according to a third aspect of the present invention is the radio wave absorber according to the first aspect, characterized in that the peripheral portion of the groove or recess is recessed inward from the adhesive surface. is there.

A radio wave absorber according to a fourth aspect is a block-shaped radio wave absorber made of a foamed resin material mixed with a conductor powder, wherein the inside of the radio wave absorber is bonded to engage with the radio wave absorber. The auxiliary member is embedded, and a part of the adhesion auxiliary member is exposed on the adhesive surface side of the radio wave absorber.

The method of mounting the electromagnetic wave absorber according to claim 5 is as follows:
In a method of mounting a block-shaped radio wave absorber made of a foamed resin material mixed with a conductor powder and having a groove or a recess on an adhesive surface, a through hole is provided in a plate material to which the radio wave absorber is attached, and the through hole is formed. It is characterized in that an adhesive is injected into the groove portion or the concave portion via the.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION A radio wave absorber according to the present invention includes a protruding portion (a portion having a pyramid-shaped or zigzag-shaped protrusion) 12 and a base material portion (such as a ceiling or a side wall) as shown in FIG. 1 or 2. A portion having a flat surface 11) to be adhered to, and a groove portion 21 or a concave portion 22 is provided on the adhesive surface of the base material portion 11, and the groove portion 21 or the concave portion 22 is filled with an adhesive and adhered, The adhesive strength with the ceiling and side walls of the anechoic chamber is improved.

The direction in which the groove 21 is provided is as shown in FIG.
As shown in (b), it may be (a) the longitudinal direction, (b) the lateral direction, or any other direction (oblique direction). Further, the number and position of the recesses 22 shown in FIG. 2 are not particularly limited.

Further, expanded polystyrene, expanded polyethylene,
The radio wave absorber made of a foamed resin material such as foamed phenol or foamed urethane is produced, for example, as follows.

First, a coating agent is prepared by mixing an electrically conductive powder such as carbon black or graphite with an adhesive, and then the coating agent is added to a primary expanded polystyrene foam and stirred, and then, a mold is formed. Put and secondary foam to mold.

In the case of urethane foam, it is produced by foaming it without adding a coating agent, molding it, immersing it in a coating agent, and forcibly drying it.

In the case of foamed polyethylene, a conductive powder such as carbon black or graphite is kneaded in advance with a polyethylene resin, a foaming agent is added to this kneaded material, and the mixture is put into a mold to foam. .

The groove on the adhesive surface of the base material may be formed by die molding, or may be formed by cutting after die molding. Further, a resin material having a desired groove or recess may be embedded during molding of the mold.

Next, the shape of the groove or recess will be described in detail. In the following description of the groove portion or the concave portion, the BB ′ cross section of the groove portion 21 shown in FIGS.
The CC ′ cross section, the DD ′ cross section and / or the EE ′ cross section of the concave portion 22 shown in FIG. 2 will be described.

FIG. 3 shows a case where the radio wave absorber according to the present invention is attached to the ceiling or the side wall of an anechoic chamber. As shown in the figure, in the electromagnetic wave absorber according to the present invention, the adhesive 3 is applied to the groove or the recess provided in the base member 11.
0 is filled and the electromagnetic wave absorber is adhered to the ferrite plate 40 which is generally used as the material of the ceiling or the side wall of the anechoic chamber by the adhesive 30. It may also be directly bonded to a metal plate for shielding.

Regarding the shape of the groove or recess of the radio wave absorber according to the present invention, various shapes as shown in, for example, FIGS. 4 to 9 can be considered. The groove or recess 20 shown in these drawings has a wedge-shaped or hook-shaped cross-section, and when the filled adhesive hardens, the solidified adhesive and the base material portion 11 of the radio wave absorber. It will be in a meshed state. Therefore, even if the pulling force in the direction perpendicular to the bonding surface of the base material portion 11 is applied to the solidified adhesive, it cannot be easily pulled out.

In other words, the shape of the groove or recess of the radio wave absorber according to the present invention is such that when the filled and solidified adhesive is applied with a pulling force in the direction perpendicular to the adhesive surface of the base material portion 11,
Any shape is acceptable as long as it cannot be easily pulled out. Therefore, for example, the cross-sectional shape of the groove or the recess may be a wedge shape, an L-shape, a T-shape, or the like, or the recess may be a screw hole formed by cutting.

Further, FIG. 10 shows a case where the groove or recess 20 is formed by embedding an adhesive accommodating member 23 which is processed according to the shape of the groove or the recess 20. For the adhesive agent containing member 23, a resin material or the like processed into a U-shape or an arc shape whose cross section is widened toward the end can be used.

Further, as shown in FIG. 11, in order to widen the bonding surface between the adhesive agent 30 and the ferrite plate 40, a portion recessed inward from the bonding surface of the base material portion 11 in the peripheral portion of the groove or recess ( Hereinafter, it will be referred to as an adhesive surface expansion portion). FIG.
2 shows a case where the adhesive surface expansion portion 20a is provided around the groove portion or the concave portion 20. This adhesive surface extension 20
The a is particularly effective when the opening of the groove or the recess 20 is narrowed for the reason that the mesh between the adhesive and the base material is made stronger.

Further, as shown in FIG. 13, an adhesive auxiliary member 13 having a shape that meshes with the base member 11 is embedded in the base member 11, and the adhesive auxiliary member 13 and the ferrite plate 40 are bonded by an adhesive agent 30. The radio wave absorber may be attached by bonding. In this case, the shape of the adhesion auxiliary member 13 is
A resin material having the same shape as the groove or the recess (the shape similar to the adhesive filling the groove or the recess) can be used. FIG. 14 shows an example of the adhesion auxiliary member 13, and in order to secure a space (adhesive agent accommodating portion 20b) for interposing an adhesive between the adhesion auxiliary member 13 and the ferrite plate, the adhesion auxiliary member is shown. The exposed surface of 13 is sunk inward from the adhesive surface of the base material portion 11.

In the conventional electromagnetic wave absorber, since the adhesive is applied to the adhesive surface of the base material and adhered to the ceiling or the side wall of the anechoic chamber, the surface of the ceiling or the side wall and the adhesive surface of the base material are adhered to each other. A gap is generated between the two (there is a gap due to the interposition of an adhesive), and this gap sometimes deteriorates the radio wave absorption characteristics. However, in the radio wave absorber according to the present invention,
Since the adhesive is accommodated in the groove, the recess, the adhesive surface expansion portion, or the like, a gap is not formed between the surface of the ceiling or the side wall and the adhesive surface of the base material portion, and the radio wave absorption characteristic is not deteriorated.

When the radio wave absorber according to the present invention is attached to a ceiling, a side wall, or the like, it may be adhered after filling a groove, recess, or adhesive surface expansion portion provided in the base material with an adhesive. However, it is temporarily fixed to the ceiling or the side wall in advance, and then
You may inject an adhesive agent through the through-hole provided in the ceiling or the side wall.

When the adhesive is injected into the groove, the recess, or the adhesion surface expansion portion after the electromagnetic wave absorber is temporarily fixed to the ceiling or the side wall as described above, the electromagnetic wave absorber will be the ceiling or the side wall. Due to the close contact, better electromagnetic wave absorption characteristics can be obtained. Also, the work of attaching the radio wave absorber can be performed more easily.

[0030]

As described above, the radio wave absorber according to the present invention can be firmly attached to the ceiling, the side wall, etc. of the anechoic chamber by providing the groove or recess in the base material.
Further, since it can be brought into close contact with the surface of the ceiling, the side wall, etc., good electromagnetic wave absorption characteristics can be obtained.

Further, when the adhesive is injected into the groove, the recess, or the adhesive surface expansion portion after the electromagnetic wave absorber is temporarily fixed to the ceiling or the side wall, the electromagnetic wave absorber is attached to the ceiling or the ceiling or the side wall. It becomes easier to make close contact with the side wall or the like.

[Brief description of drawings]

FIG. 1 is a perspective view showing a radio wave absorber according to the present invention (when a groove is provided).

FIG. 2 is a perspective view showing a radio wave absorber according to the present invention (when a concave portion is provided).

FIG. 3 is a cross-sectional view showing a case where the radio wave absorber according to the present invention is bonded to a ferrite plate.

FIG. 4 is a cross-sectional view showing a groove or a recess provided in a base member of a radio wave absorber according to the present invention.

FIG. 5 is a cross-sectional view showing a groove portion or a concave portion provided in the base material portion of the radio wave absorber according to the present invention.

FIG. 6 is a cross-sectional view showing a groove or a recess provided in the base material of the radio wave absorber according to the present invention.

FIG. 7 is a cross-sectional view showing a groove or a recess provided in the base material of the radio wave absorber according to the present invention.

FIG. 8 is a cross-sectional view showing a groove portion or a concave portion provided in the base material portion of the radio wave absorber according to the present invention.

FIG. 9 is a cross-sectional view showing a groove portion or a concave portion provided in the base material portion of the radio wave absorber according to the present invention.

FIG. 10 is a cross-sectional view showing a groove or a recess provided in the base material portion of the radio wave absorber according to the present invention (when an adhesive agent containing member is used).

FIG. 11 is a cross-sectional view showing a case where the radio wave absorber according to the present invention is adhered to a ferrite plate (when an adhesion surface extension is provided).

FIG. 12 is a cross-sectional view showing a groove portion or a concave portion provided in the base material portion of the radio wave absorber according to the present invention (when an adhesive surface extension portion is provided).

FIG. 13 is a cross-sectional view showing a case where the radio wave absorber according to the present invention is adhered to a ferrite plate (when an adhesion auxiliary member is embedded in a base material portion).

FIG. 14 is a cross-sectional view showing an adhesion auxiliary member embedded in a base material portion of a radio wave absorber according to the present invention.

FIG. 15 is a perspective view showing a conventional radio wave absorber and a cross-sectional view showing an adhesive portion thereof.

[Explanation of symbols]

 10 Radio Wave Absorber 10a Foamed Resin Material 10b Conductor Powder 11 Base Material Part 12 Projection Part 13 Adhesion Aid Member 20 Groove or Recess 20a Adhesion Surface Expansion Part 21 Groove Part 22 Recess 23 Adhesive Housing Member 30 Adhesive 40 Ferrite Plate

Claims (5)

[Claims] 1. A block-shaped radio wave absorber made of a foamed resin material mixed with a conductor powder, having a groove or a recess for filling an adhesive on an adhesive surface, and the shape of the groove or the recess. The electromagnetic wave absorber is characterized by having a shape that meshes with the filled and solidified adhesive. 2. The radio wave absorber according to claim 1, wherein the groove or the recess is formed by a member embedded at the time of molding. 3. The radio wave absorber according to claim 1, wherein the peripheral portion of the groove or the recess is recessed inward from the adhesive surface. 4. A block-shaped electromagnetic wave absorber made of a foamed resin material mixed with a conductor powder, wherein an adhesive auxiliary member meshing with the electromagnetic wave absorber is embedded inside the electromagnetic wave absorber, and the adhesive is applied. A radio wave absorber characterized in that a part of the auxiliary member is exposed to the adhesive surface side of the radio wave absorber. 5. A method of mounting a block-shaped radio wave absorber, which is made of a foamed resin material mixed with a conductor powder and has a groove portion or a concave portion on an adhesive surface, wherein a through hole is formed in a plate member to which the radio wave absorber is attached. A method of mounting an electromagnetic wave absorber, comprising: providing an adhesive into the groove or the recess through the through hole.