JPH09223892A - Electromagnetic shielding structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the deterioration of the shielding level of a part whose contact part cannot be covered structurally. SOLUTION: An electromagnetic shielding structure is provided by forming a shielding layer using electromagnetic shielding material and covering the internal space so as to shield the internal from the external space. A wave absorber is arranged at the front edge part of the connecting part of an opening part 10, and electromagnetic shielding material or wave absorber is arranged at the connecting part of a wall 20, floor 40 and a ceiling 30. Wave absorber is arranged at the both sides of the connecting part, and a member to which the wave absorber is previously assembled integrally is used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic shielding structure constructed by forming a shielding layer using an electromagnetic shielding material to cover an internal space and shield the external space from the external space.

[0002]

2. Description of the Related Art The applicant of the present invention discloses in Japanese Patent Laid-Open No. 62-112427.
Japanese Patent Laid-Open No. 62-230230 and Japanese Patent Laid-Open No. 62-230230 have proposed a method of performing wireless communication by using communication radio waves in a building.
When wireless communication is performed using communication radio waves, the building itself is required to have an electromagnetic shielding structure so that the frequency band can be freely selected without being restricted by the Radio Law. Regarding the electromagnetic shielding building having such a structure, for example, Japanese Patent Publication No. 6-99972 and Japanese Patent Publication No. 6-9997.
Japanese Patent Publication No. 3 and Japanese Patent Publication No. 7-16118, Japanese Patent Publication No. 6-7
No. 6706 proposes a building structure and a shielding structure for outer walls of a building, and is disclosed in Japanese Patent Publication No. 6-99971 and Japanese Patent Publication No. 6-9971.
In Japanese Patent No. 33699 and Japanese Patent Publication No. 6-13822,
Japanese Patent Publication No. 6-6340
Japanese Patent Publication No. 7, Japanese Patent Publication No. 5-79790, Japanese Patent Publication No. 3-5
Japanese Patent No. 8557 proposes a shielding structure for a window opening. Further, Japanese Patent Publication No. 3-62320, Japanese Patent Publication No. 3-45972, Japanese Patent Publication No. 3-62318,
Japanese Examined Patent Publication (Kokoku) No. 5-34159 proposes a shielding structure for each ceiling and each floor.

[0003]

However, in order to construct an electromagnetically shielded building, it is necessary to pay close attention not only to the frame as described above but also to the detailed structure not to cause radio wave leakage. Has a slight gap where a radio wave leaks at a connecting portion of a structural member such as a wall, a floor or a ceiling, that is, a joint or a butt portion. As a result, there is a problem that radio waves leak from the connecting portion and it becomes difficult to achieve a desired shielding level. Usually, the desired shielding level can be achieved by closing the electromagnetic shielding material at the connection part, but it can be fixed for opening and closing as a part that cannot be completely blocked by the electromagnetic shielding material because of its structure. There are opening and closing contact parts such as door openings and window openings at entrances and exits.

For example, in the case of a portion such as a wall, floor, or ceiling connecting portion, a conductive foil or tape is attached to the corner, or conductive putty or the like is applied to occlude and fix it constantly. Can be lost. However, in the case of a portion such as a contact portion of a door that is opened and closed, it is impossible to steadily close the contact portion by sticking a conductive foil or tape, or by coating a conductive putty or the like. Moreover, a slight amount of play is required for opening and closing, and a gap for radio wave leakage is likely to occur.

[0005]

SUMMARY OF THE INVENTION The present invention solves the above problems and suppresses a reduction in the shielding level of a contact portion that cannot be closed structurally.

To this end, the present invention is an electromagnetic shield structure in which an electromagnetic shield material is used to form a shield layer to cover the internal space and shield the external space, and the front end portion of the contact portion of the opening is provided. It is characterized in that the electromagnetic wave absorber is arranged on the wall, and the electromagnetic shield or the electromagnetic wave absorber is arranged on the connection part of the wall, floor, and ceiling other than the contact part. It is characterized in that the built-in member is used and the electromagnetic wave absorbers are arranged on both sides of the contact portion.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram for explaining an embodiment of an electromagnetic shielding structure according to the present invention, and FIG. 2 is a diagram showing a construction form of a contact portion of a door opening. In the figure, 10 is a door opening, 20 is a wall, 30 is a ceiling, 40 is a floor, 11 and 1
Reference numeral 2 is a door, and 13 is a radio wave absorber.

In FIG. 1, the door opening 10, the wall 20,
The ceiling 30 and the floor 40 are each configured to form a shielding layer using an electromagnetic shielding material so as to cover the internal space and shield from the external space. As the electromagnetic shielding material, a metal mesh or a metal foil (film) is used. There is a non-woven fabric, a sheet using other conductive fibers, a conductive paint, and the like, which are pasted or applied between the inner surface and the interior material to form the electromagnetic shielding layer. Also, the electromagnetic shielding material can be integrated into the structural material,
A steel plate serving as an electromagnetic shielding material such as a deck plate of a floor slab may be used as the structural material itself. Wall 20, ceiling 3
0, the seam of the floor 40 and the joints that are butted are fixed by electrically conductive foil or tape, etc., or by electrically conductive putty etc. However, since the door opening and closing is performed at the door opening portion 10, the contact portion cannot be closed with the electromagnetic shielding material. In the present invention, by placing a rubber ferrite or other radio wave absorber at the front end portion of the contact portion between the door and the opening that cannot be closed by the electromagnetic shielding material or the contact portion between the doors, the shielding level is reduced. It suppresses.

FIG. 2 shows an example of construction of the contact portion of the door opening. In FIG. 2, the wall 20 and the doors 11 and 12 are shown.
Is a shield layer formed using an electromagnetic shield material.
Since the doors 11 and 12 are sliding doors, the contact portion with the opening of the wall 20 and the contact portion between the doors 11 and 12 are closed with a conductive foil or tape like the connection portion described above. It is not possible. Therefore, the electromagnetic wave absorbers 13 are embedded and arranged at the front end portion of each contact portion, and in the vertical and horizontal directions. Also in the case of the automatic door type, the electromagnetic wave absorber may be similarly embedded and arranged.

At the contact portion between the door and the opening, which cannot be closed by the electromagnetic shielding material, there is a radio wave that is reflected at the front end portion thereof, passes through the contact portion, and leaks to the outside. Therefore, by disposing the radio wave absorber 13 at the front end portion of the contact portion, the radio wave is absorbed at the front end portion of the contact portion, so that the radio wave transmitted through the contact portion and leaking to the outside can be reduced. Therefore, it is possible to suppress a decrease in the shielding level at the contact portion.

FIG. 3 is a diagram showing another construction of the contact portion of the door opening, and FIG. 4 is an equivalent circuit of the contact portion of the electromagnetic shielding layer. As another construction example of the contact portion of the door opening, as shown in FIG. 3, the magnetic material 15 may be embedded along each contact portion, that is, vertically and horizontally. The contact portion of the electromagnetic shielding layer can be schematically represented by an equivalent circuit of the surface resistance Rs and the contact resistance Rc of the electromagnetic shielding layer as shown in FIG. Here, when a magnetic material is embedded in the contact portion as shown in FIG. 3, the impedance (surface resistance Rs) at the contact portion can be increased. Therefore, it is possible to reduce the leakage of radio waves from the contact portion to the outside and to suppress the reduction of the shielding level at the contact portion. Therefore, the electromagnetic wave absorber 13 is arranged at the front end of the contact portion in the same manner as in the example shown in FIG.
5 may be embedded and arranged. By doing so, it is possible to further suppress a decrease in the shielding level at the contact portion.

Further, even when the magnetic body 15 and the radio wave absorber 13 are arranged as described above, a current flows through the electromagnetic shielding material of the door and the opening frame, which causes a leak of radio waves to the outside. In some cases. However, such leakage of radio waves can be eliminated by, for example, dividing the electromagnetic shielding material by the magnetic body 15 or the electromagnetic wave absorber 13, or cutting the edge of the electromagnetic shielding material at the contact portion.

Note that the present invention is not limited to the above-described embodiment, and various modifications are possible. For example, in the above-described embodiment, the present invention is applied to the door opening, but not only to the window opening and other openings, it may be applied to the connecting portion instead of the electromagnetic shielding material, or to the electromagnetic shielding building. Although the applied example is shown, it may be similarly applied to, for example, a large-scale test facility or other electromagnetic shield structure. Also, although the electromagnetic wave absorbers are arranged on both sides of the door and the opening, they may be arranged on only one side or both sides on the outside as well as on the indoor side, and the electromagnetic wave absorbers are arranged on the surface. It may be embedded. Further, although the example of the door opening portion by the sliding door is shown, it is needless to say that the invention can be similarly applied to a door which is opened and closed by using a hinge and a contact portion with the opening portion when the revolving door is closed.

[0014]

As is apparent from the above description, according to the present invention, the radio wave absorber is arranged at the front end of the contact portion to absorb the radio wave and reflected from the front end to pass through the contact portion. Since it is possible to reduce radio waves leaking to the outside, it is possible to suppress a decrease in the shielding level at a contact portion such as a door opening that cannot be covered with a conductive tape or foil.
Therefore, conventionally, since it cannot be closed with an electromagnetic shielding material, the opening has a double structure, and when the opening is closed, a lock mechanism or the like is used to forcefully press the contact portion. Although the reduction of the shielding level is suppressed, it is not necessary to employ such a complicated structure or an extra mechanism, so that the structure can be simplified and the cost can be reduced.

Furthermore, by using a member in which the electromagnetic wave absorber is integrally incorporated in advance and bringing the factory-produced member to the site, the work of disposing the electromagnetic wave absorber on the site can be eliminated. Moreover, by using the members integrally incorporated, the work is facilitated even when the reform is performed, and the workability can be improved.

[Brief description of drawings]

FIG. 1 is a diagram for explaining an embodiment of an electromagnetic shielding structure according to the present invention.

FIG. 2 is a diagram showing a construction form of a contact portion of a door opening.

FIG. 3 is a view showing another construction mode of the contact portion of the door opening.

FIG. 4 is a diagram showing an equivalent circuit of a contact portion of an electromagnetic shielding layer.

[Explanation of symbols]

10 ... Door opening, 20 ... Wall, 30 ... Ceiling, 40 ... Floor,
11 and 12 ... Door, 13, 14 ... Electromagnetic wave absorber

Claims (4)

[Claims] 1. An electromagnetic shield structure comprising a shield layer formed of an electromagnetic shield so as to cover an inner space and shield an outer space, wherein the electromagnetic wave absorber is provided at a front end of a contact portion of an opening. An electromagnetic shielding structure characterized in that the above is arranged. 2. The electromagnetic shielding structure according to claim 1, wherein an electromagnetic shielding material or a radio wave absorber is arranged at a connecting portion of a wall, a floor and a ceiling other than the contact portion. 3. The electromagnetic shield structure according to claim 1, wherein a member in which a radio wave absorber is previously integrated is used. 4. The electromagnetic shield structure according to claim 1, wherein the electromagnetic wave absorbers are arranged on both sides of the contact portion.