JPH07249889A - Radio dark chamber - Google Patents

Abstract

PURPOSE:To shorten a site executing time and to eliminate a skilled operator by effectively mounting a dielectric plate on a double shielded panel as a radio reflector without impairing electromagnetic shielding characteristics, previously adhering a radio absorbing member to a front surface of the plate, and improving operability at the time of assembling. CONSTITUTION:When double shielded panels 1 having shielding members 3A, 3B provided on both surface of a core material 2 are used as a radial shielding member and a radio reflector, a dielectric plate 7 is disposed thereon and ferrite tiles 10 are disposed on the plate 7 so as to become an indoor side surface, the plate 7 is mounted at the panel 1 with a screw 8 which penetrates the first member 3A of the panels 1 from indoor side of the plate 7 and the panel 1 but does not penetrate the second member 3B.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention measures the radiated noise electric field strength of a device that generates radio noise that gives a radio disturbance to other electronic devices, and irradiates the electronic devices with radio waves of a strong electromagnetic field to test for malfunction. In the case of anechoic chambers used when doing, etc., especially with double shield panels to provide electromagnetic shielding for the entire room,
The present invention relates to an anechoic chamber using a multilayer type electromagnetic wave absorber in which a structure in which a dielectric is provided on the back surface of an electromagnetic wave absorbing member such as ferrite is arranged on a double shield panel.

[0002]

2. Description of the Related Art Conventionally, JP-A-2-357 proposed by the present applicant.
No. 97 discloses a multilayer type electromagnetic wave absorber in which a ferrite is provided on the outermost surface in the direction of arrival of radio waves, a dielectric is laminated on the entire back surface thereof, and a radio wave reflector is provided on the entire back surface thereof, and a panel core material. It is disclosed that a double shield panel having conductor plates provided on both surfaces thereof is used as a radio wave reflector.

The attachment of such a multilayer type electromagnetic wave absorber to the double shield panel on the inner surface of the electromagnetic wave dark room is generally performed by an adhesive.

An epoxy adhesive is generally used to attach the dielectric to the double shield panel and ferrite to the dielectric from the viewpoint of reliability. The distance between the back of the ferrite and the surface of the indoor shield member of the double shield panel that forms the radio wave reflector affects the electromagnetic wave absorption characteristics, including the material and thickness of the dielectric and adhesive in the middle of them. Has become.

Further, the multilayer type electromagnetic wave absorber ferrite has a characteristic thickness of several mm and has a tile shape with vertical and horizontal dimensions of about 100 mm. One piece of this ferrite is used as a dielectric on site with an adhesive. One is attached.

[0006]

By the way, in the case of constructing an anechoic chamber using the multilayer type electromagnetic wave absorber as described above, there are the following problems.

(1) Even if a highly reliable adhesive, for example, an epoxy adhesive is used when attaching the dielectric, the dielectric and the radio wave reflector are not enough to handle the adhesive in the field and the durability is poor. Peeling occurs between the double shield panels formed, and a dielectric material (for example, a special plywood with a vertical dimension of 1800 mm and a horizontal dimension of 900
There is a risk of causing problems such as a fall accident of about mm (relatively large). In particular, there is a big problem in the case of a fall accident on the ceiling surface.

(2) When mounting the dielectric, it is necessary to support the dielectric until the adhesive is cured,
There is a problem that it takes time to carry out the construction on site.

(3) The distance between the back surface of the ferrite and the surface of the double shield panel forming the radio wave reflector depends not only on the thickness of the dielectric but also on the thickness of the adhesive. Careful attention must be paid to the method or the method of supporting the dielectric material, and if the thickness of the adhesive layer exceeds the allowable range, the radio wave absorption characteristics may be deteriorated.

(4) The problem that the work period is long because ferrite is pasted on the surface of the dielectric on the site, and that a worker with high skill is required to control the thickness of the adhesive as in (3). There is.

In view of the above points, the present invention makes it possible to reliably attach a dielectric plate to a double shield panel as a radio wave reflector without impairing the electromagnetic wave shield characteristics.
In addition, it is possible to attach a radio wave absorbing member such as ferrite to the front surface of the dielectric plate, which improves workability during assembly, shortens field construction time, and eliminates the need for skilled workers. The purpose is to provide a dark room.

[0012]

In order to achieve the above object, in the anechoic chamber of the present invention, a double shield panel in which conductor plates are provided on both sides of a panel core material is used as an electromagnetic wave shield member and a radio wave reflector. In this configuration, a dielectric plate is placed on the dielectric plate, and a radio wave absorbing member is placed on the dielectric plate so as to be the indoor side surface. From the indoor side of the dielectric plate and the double shield panel, The dielectric plate is attached to the double shield panel with a mounting hardware that penetrates the conductor plate as the first shield member of the double shield panel but does not penetrate the conductor plate as the double shield member. It is characterized by that.

Further, the mounting hardware has a male screw having a length dimension which penetrates the conductor plate serving as the first shield member of the double shield panel but does not penetrate the conductor plate serving as the double shield member. It may be a member.

Further, an adhesive may be used together with the dielectric plate to be attached to the double shield panel.

A ferrite tile may be used as the radio wave absorbing member, and a plurality of the ferrite tiles may be attached to the indoor surface of the dielectric plate to form a radio wave absorbing panel.

[0016]

In the anechoic chamber of the present invention, the electromagnetic wave absorbing member such as a ferrite tile is arranged on the indoor side first shield member of the double shield panel with the dielectric plate on the indoor side surface. In this case, instead of attaching the dielectric plate to the double shield panel only with an adhesive, a mounting hardware such as a screw is used, and the mounting hardware is used as the first shield member for the dielectric plate and the double shield panel. The dielectric plate can be attached by penetrating through the conductor plate and being fixed to the panel core material, and the dielectric plate can be attached quickly and reliably.

Further, the structure is such that only the first shield member from the indoor side of the double shield panel is penetrated by the mounting hardware such as a screw, and the gap between the mounting hardware and the first shield member generated at this time With respect to the electric wave leakage, the conductor plate as the outer double shield member maintains the shielding effect, so that the problem of electromagnetic wave shielding does not occur.

Further, a radio wave absorbing member such as ferrite may be attached in advance to the front surface of the dielectric plate to form a panel block before the on-site construction.

[0019]

Embodiments of an anechoic chamber according to the present invention will be described below with reference to the drawings.

A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a sectional view of an anechoic chamber of the first embodiment, FIG. 2 is a front view of a state in which a dielectric plate is attached to a double shield panel as seen from the inside, and FIG. 3 is a top view of the dielectric plate. It is the front view which looked at the state where the ferrite tile was stuck to from the indoor side.

In these figures, reference numeral 1 denotes a double shield panel, in which a conductor plate serving as the first shield member 3A is provided on the indoor side of the panel core 2 and a conductor serving as the double shield member 3B is provided outside the panel. It is a so-called sandwich type in which the plates are fixedly integrated with each other, and the first and second shield members 3A and 3B are spaced at a constant interval. As the panel core material 2, a so-called particle board in which wood is chipped and compression-molded is used, but a core material such as a corrugated cardboard roll core, a foamed polystyrene foam, or a foamed polyurethane may be used. A so-called zinc-iron plate obtained by galvanizing an iron-conducting plate is used as the conductor plate serving as the shield members 3A and 3B.

The double shield panel 1 is connected and fixed to each other by a steel flat metal plate 4, a steel tightening metal 5, and a steel countersunk screw 6, and is shield-connected so that an electromagnetic wave shield can be maintained. . Here, the tightening hardware 5 is a head portion 5 that abuts on the flat metal article 4 from the upper surface of the bent portion 5A that abuts on the outdoor side surface of the double shield panel 1.
The height dimension up to the upper surface of B is set to be slightly shorter than the wall thickness of the connecting portion of the double shield panel 1, and the double shield panel 1 is connected between the flat plate metal article 4 and the bent portion 5A of the tightening metal article 5. The double shield panel 1 is formed by the flat metal plate 4 and the tightening metal product 5 by inserting the end portion which is a portion and then penetrating the flat metal product 4 and tightening the countersunk screw 6 which is screwed into the head 5B of the tightening metal product 5. The end portion can be reliably clamped. Although a female screw hole may be formed in advance in the head portion 5B of the tightening member 5 and the countersunk screw 6 may be screwed, a prepared hole may be provided in the head portion 5B and a self-tapping screw may be used as the countersunk screw 6. You may screw it in.

In this way, by connecting a plurality of double shield panels 1 and making a shield connection, the wall body of the anechoic chamber is provided with an electromagnetic wave shield so that radio waves do not leak or enter. .

As shown in FIG. 2, one dielectric plate 7 is of a substantially standard size and has a vertical dimension of 1800 mm, a lateral dimension of 900 mm, and a thickness of 9 mm.
It is a special plywood or the like. Countersunk screw 8 made of steel and having a cross hole as a mounting hardware for mounting the dielectric plate 7
Has a length dimension that allows the first shield member 3A on the indoor side of the double shield panel 1 to penetrate, but does not penetrate the double shield member 3B on the outer side when viewed from the indoor side.

To mount the dielectric plate 7 on the interior side of the double shield panel 1, as shown in FIGS. 1 and 2, a steel plate countersunk screw 8 is pierced through the dielectric plate 7 and is single-layered. This is performed by penetrating the eye shield member 3A and screwing it into the panel core material 2 using an electric screwdriver or the like. At this time, the flat wood screw 8 has a shape that bites into the surface of the special plywood or the like that is the dielectric plate 7, and there is no problem that the screw head portion projects when the ferrite tile is attached in the next step.
Here, as shown in FIG. 2, one dielectric plate 7 has 9
The case where the screws are screwed at the points is illustrated. At the time of this screwing, as shown in FIG. 1, it is possible to use the epoxy adhesive 9A together and attach the dielectric plate 7. In particular,
When the core material 2 of the double shield panel 1 is a roll core or a foam and the pull-out strength of the screw cannot be expected so much, it is necessary to mount the adhesive together.

The ferrite tile 10 as the radio wave absorbing member is made of Ni--Zn type ferrite having a large magnetic permeability.
It is formed in a square of 0 cm and a thickness of about several mm, and as shown in FIG. 3, it is adhered and fixed to the front surface of the dielectric plate 7 with an epoxy adhesive 9B for tiles. As a result, the ferrite tile 10 is arranged so as to be the outermost surface on the indoor side (the outermost surface in the radio wave arrival direction).

2 and 3, the wall body of the double shield panel 1 is partially provided with the dielectric plate 7 and the ferrite tile 10, but the double shield panel 1 Is usually arranged on the entire surface of the outer shell structure of the anechoic chamber, that is, on the four side surfaces, the ceiling surface and the floor surface, and the dielectric plate 7 and the dielectric plate 7 are provided on the indoor side of the double shield panel 1 on at least the four side surfaces and the ceiling surface. A ferrite tile 10 is provided.

As described above, the anechoic chamber is constructed by attaching the ferrite tile 10 to the indoor side surface of the dielectric plate 7 attached to the double shield panel surface with an epoxy adhesive.

According to the first embodiment described above, the following effects can be obtained.

(1) A dielectric plate 7 such as a special plywood plate can be fixed to the double shield panel 1 forming a radio wave reflector with a countersunk screw 8 having a cross hole, and the double shield panel 1 can be removed by peeling the adhesive. There is no fear of the dielectric plate 7 falling.

(2) Since the dielectric plate 7 is fixed with the screw 8, it is not necessary to support the dielectric plate 7 for the time until the adhesive is hardened, and the labor of construction can be saved.

(3) Since the length of the screw 8 for fixing the dielectric plate 7 is set so as not to penetrate the double shield member 3B of the double shield panel 1, the screw 8 is fixed.
Does not deteriorate the electromagnetic wave shield performance that occurs when the penetrating the shield member.

(4) The dielectric plate 7 is fixed to the screw 8 and the adhesive 9A.
By using the double shield panel 1 and the core material 2 of the double shield panel 1 in combination with each other, reliable and durable mounting is possible.

FIG. 4 shows a second embodiment of the present invention. In this case, on the indoor side surface (front surface) of the dielectric plate 7, a ferrite tile 10 is previously attached with an epoxy adhesive for tiles (adhesive 9B in FIG. 1) to fabricate a radio wave absorption panel 11. . However, before mounting the radio wave absorption panel 11, FIG.
No ferrite tile is attached to the position P. In this figure, the dielectric plate 7 is a standard plywood standard size,
The vertical dimension is about 1800 mm and the horizontal dimension is about 900 mm.
Is set at 9 points for each standard plywood. At these positions P, the radio wave absorption panel 11 in which the ferrite tile 10 and the dielectric plate 7 are integrated with an adhesive is attached to the double shield panel 1 with a cross recessed screw 8. At this time, an adhesive may be used in combination as in the first embodiment. After the radio wave absorption panel 11 is attached to the double shield panel 1 with the screw 8, the ferrite tile 10 not attached to the position P is attached with an adhesive to form an anechoic chamber. Incidentally, the same or corresponding parts as those of the first embodiment described above are designated by the same reference numerals, and the description thereof will be omitted.

According to the second embodiment, the radio wave absorbing panel 11 can be constructed by previously bonding and integrating the ferrite tile 10 to the dielectric plate 7, and the time required for on-site construction can be shortened. The advantage is that no skilled worker is required.

In the second embodiment, the electric wave absorbing panel 11 without the ferrite tile attached at the position P is screwed at the position P and attached to the double shield panel 1, and the position P is provided later. The case where the ferrite tile is pasted is shown as an example. Double shield panel 1
A screw or other mounting hardware is fixed to the front surface of the dielectric plate 7, and the surface of the dielectric plate 7 facing the double shield panel is provided with a metal, a hole, or the like that can be fitted with the screw or other mounting hardware. It is also possible to previously attach the ferrite tile 10 to the entire surface of the dielectric plate 7 including the portion P so as to form a radio wave absorption panel.

The conductor plates serving as the shield members 3A, 3B may be steel plates, stainless steel plates, copper plates, brass plates, aluminum plates, etc., in addition to the so-called zinc iron plates obtained by galvanizing iron plates. Also, the flat plate metal 4, the tightening metal 5,
The countersunk screw 6 and the countersunk screw 8 with a cross hole may be made of a metal material other than steel.

It is also possible to fix the dielectric plate 7 to the double shield panel 1 by using other mounting hardware in place of the countersunk screw 8 with a cross hole.

Although the embodiment of the present invention has been described above, it is obvious to those skilled in the art that the present invention is not limited to this and various modifications and changes can be made within the scope of the claims. Let's do it.

[0040]

As described above, in the anechoic chamber of the present invention, the double shield panel having the conductor plates provided on both sides of the panel core is used as the electromagnetic wave shield member and the electromagnetic wave reflector, and the dielectric is provided on the double shield panel. When disposing a body plate and further disposing the electromagnetic wave absorbing member on the dielectric plate so as to be the surface on the indoor side, the dielectric plate and the double shield panel from the indoor side to the double shield panel Since the conductor plate as the first shield member penetrates but the conductor plate as the double shield member does not penetrate, the dielectric plate is attached to the double shield panel. Can be securely attached to a double shield panel that forms a radio wave reflector.

In addition, the dielectric plate can be immediately attached to the double shield panel, and the dielectric plate can be supported for a time until the adhesive is cured, which is required in the conventional structure using only the adhesive. Is unnecessary, and the labor of construction can be saved.

Further, by attaching a radio wave absorbing member such as ferrite to the front surface of the dielectric plate in advance, workability at the time of assembling can be improved, shortening the on-site construction time and eliminating the need for a skilled worker. it can.

Further, since the mounting hardware such as the screw does not penetrate the double shield member, the electromagnetic shielding performance, which is a problem when the mounting hardware such as the screw penetrates the shield member, does not occur.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a first embodiment of an anechoic chamber according to the present invention.

FIG. 2 is a front view seen from the inside of the room in the state where the dielectric plate is attached to the double shield panel with a screw in the first embodiment.

FIG. 3 is a front view seen from the inside of the room in a state where a ferrite tile is attached to the front surface of the dielectric plate in the first embodiment.

FIG. 4 is a front view showing a state in which a double shield panel is mounted with an electric wave absorption panel in which a ferrite tile is previously attached to an inner surface of a dielectric plate in a second embodiment of the present invention.

[Explanation of symbols]

 1 Double Shield Panel 2 Panel Core Material 3A, 3B Shielding Member 4 Flat Plate Hardware 5 Tightening Hardware 6 Plate Screw 7 Dielectric Plate 8 Cross Plate Screws 9A, 9B Adhesive 10 Ferrite Tile 11 Radio Wave Absorption Panel

Claims (4)

[Claims] 1. A double shield panel having conductor plates provided on both surfaces of a panel core material is used as an electromagnetic wave shield member and a radio wave reflector, and a dielectric plate is disposed on the double shield panel, and further on the dielectric plate. In the anechoic chamber in which the radio wave absorbing member is arranged on the indoor side surface, the conductor plate as the first shield member of the double shield panel penetrates from the indoor side of the dielectric plate and the double shield panel. The anechoic chamber is characterized in that the conductor plate as a double shield member is a metal fitting that does not penetrate, and the dielectric plate is attached to the double shield panel. 2. A male screw member having a length dimension in which the mounting hardware penetrates a conductor plate serving as a first shield member of the double shield panel but does not penetrate a conductor plate serving as a double shield member. The anechoic chamber according to claim 1. 3. The anechoic chamber according to claim 1, wherein an adhesive is also used for attaching the dielectric plate to the double shield panel. 4. The radio wave absorbing member is a ferrite tile, and the ferrite layer is formed on the indoor surface of the dielectric plate.
The anechoic chamber according to claim 1, 2 or 3, wherein a plurality of tiles are attached to form an electromagnetic wave absorption panel.