JPH07307593A - Anechoic enclosure - Google Patents

Abstract

PURPOSE:To obtain an anechoic enclosure of high performance and good construction workability by preventing wave absorption performance from lowering due to generation of a magnetic clearance between a ferrite board applied to an electromagnetic shield panel in advance and a ferrite board to be applied to a joint part. CONSTITUTION:An anechoic enclosure is provided with a junction structure of a ferrite board wherein a plurality of electromagnetic wave shield panels 10 wherein ferrite boards 13, 14 are applied to a region excepting a shield connecting part 30 are connected mutually by a shield connection part 30 and a ferrite board 16 covering the shield connection part 30 and a side edge part of the ferrite board 14 on an electromagnetic wave shield panel adjoining thereto are joined mutually by a shiplap structure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention accommodates a device or the like that generates radio noise that causes radio interference to other devices, or malfunctions by radiating a strong electric field to electronic devices, particularly semiconductor-mounted devices. This relates to an anechoic chamber used when testing characteristics.

[0002]

2. Description of the Related Art Conventionally, Japanese Patent Application No. 5-2 proposed by the present applicants
No. 08168 and the like disclose an anechoic chamber using an outer wall of a building that houses the anechoic chamber, an electromagnetic wave shield plate, and an electromagnetic wave shield panel in which an electromagnetic wave absorber such as ferrite is attached. In this case, the area where the electromagnetic wave absorber such as ferrite is pasted is made smaller than the size of the electromagnetic wave shield panel, and after the shield connection part between the electromagnetic wave shield panels (the part to be connected and connected in the shield state) is constructed on site. , The method of pasting the electromagnetic wave absorber such as ferrite to the part including this shield connection part is taken (Hereafter, the part where the electromagnetic wave absorber such as ferrite is pasted is
It is called a joint. ).

It is necessary that the electromagnetic wave absorber previously attached to the electromagnetic wave shield panel and the electromagnetic wave absorber to be attached to the shield connecting portion at the site are in close contact with each other as much as possible. In particular, in the case of a ferrite electromagnetic wave absorber, it is necessary to be so-called magnetically continuous in the direction of the magnetic field component of the incident electric wave, and if a magnetic discontinuity occurs, the electromagnetic wave absorption performance deteriorates due to the action of the demagnetizing field.

In order to prevent the deterioration of the electromagnetic wave absorption performance due to the gap between the ferrite electromagnetic wave absorbers, for example, in Japanese Utility Model Publication 55-5.
As shown in No. 2717, there is a method in which a ferrite electromagnetic wave absorber has a mating structure.

[0005]

When an anechoic chamber is constructed using the electromagnetic wave shield panel having the ferrite electromagnetic wave absorber attached as described above, there are the following problems.

(1) Dimensional variations occur at joints of the electromagnetic wave shield panel due to wall surfaces of an anechoic chamber composed of a large number of electromagnetic wave shield panels, and when a ferrite plate to be stuck on site at the joints has a constant dimension is used. However, there is a problem that a gap is formed between a ferrite plate previously attached to the electromagnetic wave shield panel and the electromagnetic wave absorption characteristic is deteriorated, or the ferrite plate is larger than the joint size and cannot enter the joint.

(2) In order to solve the above problems, it is possible to prepare on-site ferrite plates of various sizes depending on the variation of joint size, but there is a problem in terms of labor and unnecessary construction period. There is.

(3) Reducing the variation in joint size is one of the means for solving the above problems. The variation in the joint size is caused by the variation in the size of the ferrite plate previously attached to the electromagnetic wave shield panel, the skill of the operator, the variation in the size of the electromagnetic wave shield panel, the accuracy at the time of mounting, and the like. There is a limit in terms of current technology and cost to suppress the above factors and reduce the variation in joint size.

(4) In order to prevent the deterioration of the electromagnetic wave absorption performance due to the gap between the ferrite plates, it is better to make all the ferrite plates to be attached to the electromagnetic wave shield panel into a mating structure than to use a ferrite plate not having this structure. However, the manufacturing cost will increase, and problems such as damage when attaching the mating processed product will occur.

In view of the above points, the present invention provides a magnetic gap between a ferrite plate as an electromagnetic wave absorber previously attached to an electromagnetic wave shield panel and a ferrite plate to be attached to a joint portion, thereby improving the electromagnetic wave absorption performance. It is an object of the present invention to provide an anechoic chamber having high performance and excellent construction workability by preventing the deterioration.

[0011]

In order to achieve the above object, the first invention of the present application is such that a plurality of electromagnetic wave shield panels having ferrite plates attached to regions other than the shield connecting portion are mutually connected at the shield connecting portion. In a anechoic chamber constructed by connecting, a ferrite plate that covers the shield connection portion and at least one side edge portion of the ferrite plate on the electromagnetic wave shield panel adjacent to the ferrite plate is joined together in a mating structure. It has a joint structure.

The second invention of the present application is the shield connection in an anechoic chamber constituted by connecting a plurality of electromagnetic wave shield panels, each having a ferrite plate attached thereto in a region other than the shield connection portion, at the shield connection portion. It is equipped with a ferrite plate joint structure in which a ferrite plate covering the part is divided into a plurality of parts and joined to each other in a mating structure.

[0013]

According to the present invention, it is possible to suppress the deterioration of the electromagnetic wave absorption characteristic due to the dimensional variation of the joint portion inevitable in this type of anechoic chamber. That is, regardless of variations in joint dimensions including shield joints that connect electromagnetic wave shield panels to each other, a ferrite plate as a radio wave absorber is used to create a radio wave absorber by utilizing a mating structure of adjacent ferrite plates in joints. It is possible to magnetically continue in the direction of the magnetic field component, and it is possible to easily prevent deterioration of the radio wave absorption performance.

[0014]

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. In the overall configuration of FIG. 3, reference numeral 1 is a frame of an outer shell structure of an anechoic chamber, and a core member 3 is attached to the frame 1 via a mounting plate 2.
Are connected and fixed. The frame 1, the mounting plate 2, and the core member 3 are all made of steel, etc., and an electromagnetic wave shield plate 11 made of a metal plate such as a steel plate of the electromagnetic wave shield panel 10 is fixed on the core member 3 by welding or the like. .

As shown in FIGS. 1 to 3, the electromagnetic wave shield panel 10 includes an electromagnetic wave shield plate 11 and a ferrite plate (ferrite tile) 13 as an electromagnetic wave absorber, which is attached to the surface of the electromagnetic wave shield plate 11 with an adhesive 12 in advance. , 14 and.

The electromagnetic wave shield plate 11 is made of a metal plate such as a steel plate, and its four side edges are ferrite plates 13 and 14.
It is bent to have an L-shaped cross section so as to form a stepped surface 20 for shield connection that is one step lower than the surface to which is attached, and a folded back surface 21 for shield connection that is parallel to the stepped surface 20 is formed. It is folded back to have an L-shaped cross section.

The ferrite plates 13 and 14 are adhered to a region of the surface of the electromagnetic wave shield plate 11 other than the joint portion 15 (shield connecting portion and both side portions along the joint portion) without any gap. However, the ferrite plate 13 is a simple rectangular plate having no interlocking structure, and the ferrite plate 14
The side edge portion on the side facing (contacting) the joint portion 15 has a mating structure. That is, the side edges of the ferrite plate 14 are halved in thickness so that the step surface 1
4a.

FIGS. 2 and 3 show a state before the ferrite plate of the joint portion 15 is attached. Before the ferrite plate is attached to the joint portion 15, the electromagnetic shield panels 10 are shielded to each other (electromagnetic waves enter and leak). Do not connect the cable while keeping the shield state)
Run in. That is, the inner eye plate 22, which is a metal plate such as a plated steel plate, is brought into contact with the step surface 20 of the adjacent electromagnetic wave shield plate 11, and the outer eye plate 23 is brought into contact with the folding surface 21, so that the inner eye plate 22 and the outer eye plate By tightening with a bolt 24 that penetrates both of the plates 23 and a nut 25 that is screwed into this,
The electromagnetic wave shield plates 11 of the adjacent electromagnetic wave shield panels 10 are shield-connected. Such a shield connecting portion 30 is located at a position lower than the surface of the electromagnetic wave shielding plate 11 to which the ferrite plates 13 and 14 are attached due to the provision of the step surface 20, and at the side edge portion of the adjacent electromagnetic wave shielding plate 11. The opening of the recessed portion 31 whose bottom surface is the stepped surface 20 is closed flat by fitting a joint plate (joint cover) 32, which is a metal plate such as a plated steel plate, into the opening of the recessed portion 31. . The joint plate 32 is not shown in FIG.

As shown in FIG. 1, the on-site-attached ferrite plate 16 to be installed in the joint portion 15 including the shield connection portion 30 and both sides thereof has a structure in which both side edges of the joint portion 15 in the width direction are fitted. Has become. That is, the ferrite plate 1 previously attached to the electromagnetic wave shield panel 10
4 so that it can contact the step surface 14a
Both side edges have a stepped surface 16a by reducing the thickness to about half.

After the shield connection between the electromagnetic wave shield panels 10 is completed as shown in FIG. 2, a ferrite plate 16 having a mating structure having step surfaces 16a on both sides is jointed with an adhesive 12 as shown in FIG. That is, the joint plate 32
And the surface of the electromagnetic wave shield plate 11 on both sides thereof. At this time, the widthwise dimensions W1, W2 of the joint portion 15
(However, W1: the distance between the end faces 14b at the retracted position at the position where the step surface 14a of the ferrite plate 14 is formed, W2: the distance between the front end faces of the ferrite plate 14) varies, and the front end face of the ferrite plate 16 and the ferrite plate 16 Even if a gap G is generated between the ferrite plates 14 and 16, the step surface 1 of the ferrite plates 14 and 16
Since 4a and 16a are in surface contact with each other, magnetic continuity can be maintained.

An electromagnetic wave absorbing wall structure in which the electromagnetic wave shield panels 10 to which the ferrite plates 13 and 14 are attached in advance as shown in FIG. 1 are connected to each other and the ferrite plate 16 is provided so as to be magnetically continuous with the joint portion 15. The body constitutes the necessary surfaces (four sides and the ceiling surface) of the anechoic chamber. Usually, the floor surface is not provided with a ferrite plate and is often an electromagnetic wave shield plate, but a ferrite plate may be provided on the floor surface as well.

It is not necessary that the both sides of the field-bonded ferrite plate 16 in the longitudinal direction of the joint portion 15 have a mating structure. This is because the ferrite plate 16 can be installed without gaps in the longitudinal direction of the joint portion 15. Further, the mating process of the ferrite plates 14 and 16 is carried out as a normal rectangular plate by firing and then the stepped surface 14
a, 16a may be formed, or the step surface 14 may be formed from the beginning.
You may bake so that it may have a and 16a.

According to the first embodiment, there are variations in the widthwise dimensions W1 and W2 of the joint portion 15, and the front end surface of the on-site attached ferrite plate 16 and the electromagnetic wave shield panel 10 are made.
Even if a gap G is generated between the ferrite plate 14 located at the end of the magnetic field, the step surfaces 14a and 16a formed by the ferrite plates 14 and 16 having the interlocking structure are in surface contact with each other, and therefore magnetically generated. It is possible to maintain continuity and prevent deterioration of electromagnetic wave absorption performance. It should be noted that one side edge of the ferrite plate 14 facing the joint portion 15 of the electromagnetic wave shield panel 10 has a mating structure, but the ferrite plate 13 inside this may be a general rectangular plate, and the electromagnetic wave shield panel 10 Is easy to manufacture and is advantageous in terms of cost.

FIG. 4 shows a second embodiment of the present invention. In this case, one of the ferrite plates facing the joint portion 15 of the electromagnetic wave shield panels 10 connected to each other is the ferrite plate 14 having a mating structure, but the other one does not have a mating structure. It is a ferrite plate 13. The field-bonded ferrite plate 26 corresponding to the joint portion 15 has a mating structure corresponding to the ferrite plate 14 only on one side edge portion. That is, a step surface 26a having a mating structure corresponding to the step surface 14a of the ferrite plate 14 is formed on one side edge of the ferrite plate 26. The rest of the configuration is the same as that of the first embodiment described above, and the same or corresponding parts will be assigned the same reference numerals and explanation thereof will be omitted.

According to the second embodiment, the widthwise dimensions W3 and W4 of the joint portion 15 including the shield connection portion 30 (where W3: the end face 14b at the retracted position of the step surface 14a forming position of the ferrite plate 14 and the ferrite). There is a variation in the distance between the front end surfaces of the plate 13 and W4: the distance between the front end surfaces of the ferrite plates 13 and 14), and the ferrite plate 26 stuck on the spot
Even if a gap G occurs between the tip surface of the ferrite plate 14 and the ferrite plate 14 located at the end of the electromagnetic wave shield panel 10, one side edge portion of the ferrite plates 14 and 26 is formed as a mating structure 14a. , 26a are in surface contact with each other, it is possible to maintain magnetic continuity and prevent deterioration of electromagnetic wave absorption performance. It should be noted that, with respect to the ferrite plate 13 that does not have the interlocking structure facing the joint portion 15 of the electromagnetic wave shield panel 10, one end face of the ferrite plate 26 may be closely attached to the end face of the ferrite plate 13 so as not to create a gap. It is possible, and there is no deterioration in electromagnetic wave absorption performance in this part. Also, the electromagnetic wave shield panel 1
The joint part 1 of the ferrite plate that is attached in advance to 0
It is possible to make the ferrite plate 14 having a mating structure only on one side facing 5 and the other ferrite plates on the electromagnetic wave shield panel to be an ordinary rectangular plate, so that the electromagnetic wave shield panel can be easily manufactured. That is,
By reducing the number of ferrite plates with an interlocking structure, it is possible to suppress an increase in manufacturing cost and reduce damage accidents during attachment.

A third embodiment of the present invention will be described with reference to FIGS. In the third embodiment, a ferrite dividing plate 3 obtained by dividing a field bonding ferrite plate to be bonded on site to the joint portion 15 of the electromagnetic wave shield panels 10 connected to each other is divided into two.
6, 37 are used. FIG. 5 shows a ferrite division plate 36,
After attaching 37, FIG. 6 shows a state before attaching.

As shown in FIG. 6, the ferrite plates pre-attached to the electromagnetic wave shield panels 10 connected to each other, including the ones facing the joints 15, are all square plate ferrites having no mating structure. It is a plate 13.

On the other hand, as shown in FIG. 5, the ferrite split plates 36 and 37 each having a shape obtained by dividing a field-attached ferrite plate to be pasted on the joint portion 15 at the site are divided into two, and the side edges adjacent to each other have a mating structure. Has become. That is, one side edge portion of each of the ferrite split plates 36 and 37 has step surfaces 36a and 37a that can be brought into surface contact with each other by reducing the thickness thereof to about half. The rest of the configuration is the same as that of the first embodiment described above, and the same or corresponding parts will be assigned the same reference numerals and explanation thereof will be omitted.

According to the third embodiment, there is a variation in the widthwise dimension W5 (distance between the tip surfaces of the ferrite plates 13) of the joint portion 15 including the shield connection portion 30, and the ferrite division plate 36 attached in the field is present. Even if a gap G is generated between the end surface 36b at the retracted position at the position where the step surface 36a is formed and the front end surface of the ferrite split plate 37, the ferrite split plate 3
Since the step surfaces 36a and 37a, which are formed by interlocking adjacent side edge portions of 6, 7 and 37, are in surface contact with each other, magnetic continuity can be maintained and deterioration of electromagnetic wave absorption performance can be prevented. be able to. For the ferrite plate 13 that does not have a mating structure that faces the joint portion 15 including the shield connection portion 30 that connects the electromagnetic wave shield panels 10 to each other, on the site, each ferrite split plate 36, It is possible to closely attach one end surface of 37 so as not to create a gap, and there is no deterioration in radio wave absorption performance at this portion. In addition, all the ferrite plates that are attached to the electromagnetic wave shield panel 10 in advance can be ordinary rectangular plates, which makes it easier to manufacture the electromagnetic wave shield panel. That is, the ferrite plate on the electromagnetic wave shield panel 10 does not have a mating structure, thereby reducing the manufacturing cost and preventing a damage accident at the time of attachment due to the mating structure.

Although it is ideal to employ the interlocking structure of the above-described first, second or third embodiment for the joint portion of the entire area where the ferrite plate of the anechoic chamber is arranged,
In particular, the configuration may be limited to only a region where a problem occurs when the radio wave absorption performance of the main reflection surface of the anechoic chamber decreases.

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.

[0033]

As described above, according to the anechoic chamber of the present invention, a plurality of electromagnetic wave shield panels in which ferrite plates serving as electromagnetic wave absorbers are previously attached to areas other than the shield connecting portion are provided in the shield connecting portion. In the case of attaching a field-attached ferrite plate to the joint portion including the shield connection part, the field-attached ferrite plate covering the shield connection part and at least the ferrite plate on the electromagnetic wave shield panel adjacent thereto Since one side edge part is joined with a mating structure, or a field-attached ferrite plate covering the shield connection part is divided into multiple parts and joined together with a mating structure, a ferrite plate with Combined with an electromagnetic wave shield panel, it has the effect of shortening the construction period, reducing the construction cost, etc. A reduction in electromagnetic absorption performance caused by the variations in the joint dimensions of the shield connecting portion can be prevented with the the electromagnetic shielding panel. In addition, the number of ferrite plates with a mating structure is the minimum necessary number of ferrite plates, etc. related to the joints including the shield connection part, and is due to the use of a ferrite plate with a mating structure. The increase in cost can be suppressed as much as possible.

[Brief description of drawings]

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

FIG. 2 is a side cross-sectional view showing a state before the on-site-attached ferrite plate is attached to the joint portion in the first embodiment.

FIG. 3 is a front view on the indoor side showing the overall configuration of the anechoic chamber in the first embodiment and showing a state before a field-attached ferrite plate is attached to a joint portion.

FIG. 4 is a side sectional view showing a second embodiment of the present invention.

FIG. 5 is a side sectional view showing a third embodiment of the present invention.

FIG. 6 is a side cross-sectional view showing a state before the on-site-attached ferrite plate is attached to the joint portion in the third embodiment.

[Explanation of symbols]

 1 Frame 2 Mounting Plate 3 Core Material 10 Electromagnetic Wave Shield Panel 11 Electromagnetic Wave Shielding Plate 12 Adhesive 13, 14, 16, 26 Ferrite Plate 14a, 16a, 26a, 36a, 37a Stepped Surface 15 Joint Part 20 Stepped Surface 21 Folded Surface 30 Shield Connection part 32 joint plate

Claims (2)

[Claims] 1. In a anechoic chamber formed by interconnecting a plurality of electromagnetic wave shield panels, each having a ferrite plate attached to an area other than the shield connecting portion, at the shield connecting portion, a ferrite plate covering the shield connecting portion and An anechoic chamber comprising a ferrite plate joining structure in which at least one side edge portion of the ferrite plate on the electromagnetic wave shield panel adjacent to this is joined to each other by a mating structure. 2. An anechoic chamber constructed by interconnecting a plurality of electromagnetic wave shield panels, each having a ferrite plate attached to an area other than the shield connecting portion, at the shield connecting portion, and a ferrite plate covering the shield connecting portion. An anechoic chamber characterized by a ferrite plate joint structure that is divided into multiple parts and joined together in a mating structure.