JP2000183580A - Magnetic shielding room - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent leakages of magnetic flux at the abutting part of sheet stock, made of an alloy with high permeability. SOLUTION: At each corner part of a magnetic shield room 10, a corner abutting part 22 where the corners of the four sheet stocks meet is covered with a first shielding member 16. At each corner part of the magnetic shield room 10, a corner abutting part 24 where the corners of the three sheet stocks 14 meet so that they cross one another nearly orthogonally is covered with a second shield member 18. On each wall surface of the magnetic shielding room 10, a wall surface abutting part 26, where the corners of the four sheet stocks 14 meet in the same plane, is covered with a third shield member 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetically shielded room, and more particularly to a magnetically shielded room capable of preventing a weak magnetic field from entering a room.

[0002]

2. Description of the Related Art For example, when measuring and detecting weak magnetism such as performing magnetoencephalography or magnetocardiography, or when drawing a fine circuit pattern with an electron beam in the manufacture of semiconductors, the measurement magnetism or the electron beam Must be shielded from being affected by external magnetic influences, and a magnetically shielded room is suitably used as a means for this. In the magnetically shielded room, a plurality of plate members made of a material having high magnetic permeability, such as permalloy, is provided on the entire wall surface of one or more layers inside or outside the casing structure constituting the main body of the room, with a gap therebetween. It is composed by mounting without. And by flowing the magnetic flux of the geomagnetism and the external fluctuating magnetic field concentratedly on the wall of the plate material having high magnetic permeability, by preventing the magnetic flux (magnetism) from leaking into the room,
This creates a space where external magnetic fields are blocked.

[0003]

In the above-mentioned magnetic shield room, it is important to mount a plurality of plate members on the wall without any gap. If there is a gap, magnetic flux leaks from the portion into the room and the shielding performance is reduced. Would. However,
It is difficult to abut a plurality of plate members so that their edges are closely contacted with each other due to the processing accuracy and assembly accuracy of the plate members, and it is inevitable that a gap is formed in the abutting portion. Therefore, a shield plate made of a high magnetic permeability material is provided so as to cover each butted portion.

[0004] At the corners where the two plate members of the magnetically shielded room abut so as to be substantially orthogonal to each other, an L-shaped shielding plate is provided so as to cover the corner portions. At present, no particular countermeasures are taken for the corners where the corners abut each other at substantially right angles. However, there is a large gap at the corner where the three plates abut, and the magnetic flux coming from three directions concentrates at the corner, so that the leakage of the magnetic flux from this gap significantly reduces the shielding performance. Had become.

[0005] In addition, although a shield plate is provided on the ceiling wall, bottom wall, and side wall of the magnetically shielded room so as to cover the butted portion where the two plate materials are butted against each other, the four plate materials are provided. No shielding plate was provided at the butting portions where the corners face each other. That is, a gap generated at a portion where the corners of the four plate members meet each other is large, and the leakage of magnetic flux from this gap significantly reduces the shielding performance.

[0006] The plate and the shielding plate are fixed using a plurality of screws. In this case, a screw hole for inserting a screw is formed in the shielding plate, and the magnetic flux leaks to the outside because the magnetic flux path is interrupted by the screw hole. If the number of screw holes is small, the leakage of magnetic flux is small, but the number of fixing screws used is large in order to closely contact the plate material and the shielding plate and to make the flow of magnetic flux between them good, so that The number of screw holes in the entire magnetic shield room is extremely large, and the leakage of magnetic flux also increases, causing a reduction in shield performance.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks inherent in the prior art, and has been proposed in order to solve the problem in a favorable manner. It is an object of the present invention to provide a magnetic shield room having high shielding performance by preventing leakage of magnetic flux at a screwed portion of a member made of a high magnetic permeability alloy.

[0008]

Means for Solving the Problems In order to overcome the above problems and appropriately achieve the intended purpose, a magnetic shield room according to the present invention comprises a plurality of plates made of a high magnetic permeability alloy.
In a magnetically shielded room assembled by arranging the edges so as to abut each other, a cap having three surfaces in contact with the respective plate members is provided at a corner where the corners of the three plate members abut at a predetermined angle. A shielding member made of a high-permeability alloy is disposed so as to cover the abutting portions at the corners.

[0009] In order to overcome the above-mentioned problems and to appropriately achieve the intended purpose, a magnetic shield room according to another invention of the present application comprises a plurality of plates made of a material having a high magnetic permeability, and A shield member made of a high-permeability alloy so as to cover a portion where the corners of the three or more plate members abut each other in the same plane in a magnetic shield room arranged and assembled so as to face each other. Are arranged so as to be in contact with all the plate members constituting the abutting portion.

[0010] In order to overcome the above-mentioned problems and appropriately achieve the intended purpose, a magnetic shield room according to still another invention of the present application comprises a plurality of plates made of a high-permeability alloy, and In a magnetically shielded room assembled and arranged so as to abut each other, a shielding member made of a high permeability alloy material covering the abutting portion of each plate is screwed using a washer of the same material as the shielding member. It is characterized by having done.

[0011] In order to overcome the above-mentioned problems and to appropriately achieve the intended object, a magnetic shield room according to yet another aspect of the present invention includes a member made of a high-permeability alloy and a material made of a high-permeability alloy. It is characterized by being screwed using a washer.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a magnetic shield room according to the present invention will be described in detail with reference to the accompanying drawings with reference to preferred embodiments.

FIG. 1 is a schematic perspective view of a magnetic shield room according to an embodiment.
A plurality of rectangular plate members 14 made of a high-permeability alloy are provided on the entire inner and outer wall surfaces of a structure in which a plurality of frames 12 (partially shown in FIG. 6) made of wood, aluminum, or the like are assembled in a rectangular shape. Installed and configured. In the embodiment,
Four plate members 14 are attached to the inner and outer ceiling wall surfaces, bottom wall surfaces, and side wall surfaces, respectively, in such a manner that the edges thereof abut against each other in the same plane. Examples of the high magnetic permeability alloy include soft magnetic materials such as Fe-45Ni (PB permalloy), 80Ni-Mo-Fe, and 78Ni-Mo-.
Cu-Fe (PC permalloy) or 70Ni-10Cu
-12Mn-Fe (PC-X) is preferably used. The thickness of the plate 14 is set to about 1 to 2 mm.

In the magnetic shield room 10, a plurality of shielding members 16 made of a high magnetic permeability alloy are used so as to cover the butted portions where the edges of the respective plate members 14 attached to the respective wall surfaces abut against each other. Numerals 18 and 20 are provided to prevent the magnetic flux from leaking at the respective butting portions. In the embodiment, the configuration of each of the shielding members 16, 18, and 20 disposed outside the magnetic shield room 10 will be described. The thickness of the shielding members 16, 18, and 20 is set to about 1 to 2 mm.

In the magnetic shield room 10, four plate members 14 are provided at the joints between the ceiling wall surface and the respective side wall surfaces, the joint portions between the bottom wall surface and the respective side wall surfaces, and the corner portions between the respective side wall surfaces. A first shielding member 16 made of an L-shaped high magnetic permeability alloy is provided on four corners of the four plate members 14, 14,.
14, 14 (all the plate members constituting the butted portion) are disposed so as to be in contact with each other, and the corner butted portion 22 is moved to the first position.
The shielding member 16 is used for covering. Further, a first shielding member 16 is disposed at a position where the two plate members 14, 14 at each corner are abutted so as to be orthogonal to each other, so as to contact the two plate members 14, 14 and cover the abutting portion. , And is configured to prevent leakage of magnetic flux at each corner.

4 in the magnetic shield room 10
A cap-shaped second shielding member 18 made of a high-permeability alloy is provided at the corner, that is, at the corner where the corners of the three plate members 14, 14, 14 abut each other so as to be substantially orthogonal to each other. I have. As shown in FIG. 2, the second shielding member 18 has three mutually orthogonal surfaces that come into contact with the three plate members 14, 14, 14, and is disposed with each surface in contact with the corresponding plate member 14. By doing so, it is configured to cover the corner butting portion 24 in the corner. Thereby, in the corner butting portion 24, as shown in FIG.
The magnetic flux concentrates and flows on the second shielding member 18 in between, thereby preventing the magnetic flux from leaking to the outside.

The four plate members 14, 14, 14, 14 in the magnetic shield room 10 have four plate members 14 on the ceiling wall surface, the bottom wall surface, and each side wall surface which are formed by abutting the edges thereof. As shown in FIGS. 4 and 5, the four plate members 14, 14, 14, 14,
A plate-shaped third shielding member 20 made of a high-permeability alloy is provided so as to be in contact with 14 (all the plate members constituting the butted portion). I cover it. In the ceiling wall, the bottom wall, and each side wall, a third shielding member 20 is provided at the abutting portion of the two plate members 14, 14 so as to cover the abutting portion. Is configured to be prevented.

The first shielding member 16 and the second shielding member 18
The fixing of the third shielding member 20 to the plate 14 is performed by the washer 28 and the screw 30 as shown in FIG.
Will be described in the case of fixing. That is, screw holes 32 and 34 for inserting the screws 30 are formed at predetermined positions of the plate member 14 and the third shielding member 20, and screw holes 12 a are screwed at corresponding positions of the frame 12. I have. Then, a washer 28 is brought into contact with the outside of the third shielding member 20, and the screw 30
Is screwed into the screw hole 12 a of the frame 12, so that the third shielding member 20 is screwed and fixed to the plate 14. The washer 28 is made of the same material as the third shielding member 20 (the plate 14), for example, the above-mentioned Fe-45Ni, 80Ni-Mo-F.
e, 78Ni-Mo-Cu-Fe or 70Ni-10
Formed from a high magnetic permeability alloy such as Cu-12Mn-Fe,
The passage of the magnetic flux is not interrupted by the screw hole 34 of the third shielding member 20. Therefore, the plate 1
The magnetic flux flowing through the fourth and third shielding members 20 flows intensively in the washer 28, whereby leakage to the outside is prevented, and a reduction in shielding performance can be suppressed.
The screw 30 may be formed of a high magnetic permeability alloy as in the case of the washer 28.

In the magnetic shield room 10 of the embodiment, the abutting portion of each plate 14 is divided into a plurality of shielding members 16, 1.
Since the magnetic gap generated by the dimensional accuracy and the assembly accuracy of the plate member 14 is reduced as much as possible by covering with the plates 8 and 20, the leakage of magnetic flux can be prevented and the shielding performance can be improved. Further, the plate member 14 and each shielding member 16,
The washer 28 used for fixing the
Since these members are formed of the same high magnetic permeability alloy, the magnetic flux does not leak at the screw holes 34 formed in the shielding members 16, 18, and 20, and the shielding performance can be improved.

[0020]

[Experimental Example] A magnetic shield room having external dimensions of 2400 mm in width, 2400 mm in depth, and 2400 mm in height was prepared using a plate material 2 made of PC permalloy and having a thickness of 2 mm. In this magnetically shielded room, plate members 14 were attached to the inner and outer surfaces on the indoor side and the outdoor side, and the distance between the surfaces was 100 mm. Each plate member 14 including the corner butting portion 22, the corner butting portion 24, and the wall butting portion 26 in the magnetic shield room.
Of the butting portions of the shielding members 16, 18, 20 of the embodiment.
(2 mm thick) was used as an example of the invention, and the shielding ratio was measured as a comparative example where the corner butting portion 22, the corner butting portion 24 and the wall butting portion 26 were not covered with a shielding member. As a result, the shielding ratio of the invention example was 55 dB, while the shielding ratio of the comparative example was 5 dB.
It was 3 dB, and it was confirmed that the shielding performance of the invention example was excellent.

In the embodiment, the case where four plates are attached to each wall surface of the magnetically shielded room has been described. However, three or five or more plates may be used. By covering the portion where the corners of the three or more plate members abut each other with the third shielding member, it is possible to prevent leakage of magnetic flux at the abutting portion. In the corner of the magnetically shielded room, three first shielding members that cover the corner to the vicinity of the corner are provided,
The corner abutting portion may be covered by disposing the second shielding member so as to be in contact with the three first shielding members. In the embodiment, the case where each shielding member is disposed outside the magnetically shielded room has been described. However, the same effect can be obtained when the shielding members are disposed inside the room. However, when the shielding member is provided on the indoor side, the contact surfaces of the first shielding member and the second shielding member with the respective plate members are opposite to those on the outdoor side.

The magnetic shield room has a portion for fixing only a member such as a hinge and a ventilation port of an opening / closing door formed of a high magnetic permeability alloy or a plate material, and screwing each member at such a portion. By using a screw and a washer (at least a washer) made of a high-permeability alloy, the shielding performance can be improved. That is, each member made of a high magnetic permeability alloy constituting the magnetic shield room
If all screws and washers used to screw (plates, shielding members, hinges, ventilation holes, etc.) are formed of a high permeability alloy material, a magnetically shielded room with extremely high shielding performance can be obtained.

[0023]

As described above, according to the magnetic shield room according to the present invention, the magnetic flux is easily concentrated by covering the corner of the room with the cap-shaped shield member formed of the high magnetic permeability alloy. Leakage of magnetic flux at corners can be reliably prevented, and shielding performance can be improved. In addition, by disposing a flat shielding member formed of a high magnetic permeability alloy so as to cover a portion where the corners of three or more plate members abut each other, a gap at the portion can be reduced. , Shielding performance can be improved. Furthermore, by forming the washer used to fix the shielding member to the plate material with the same high magnetic permeability alloy as the shielding member, it is possible to prevent the leakage of magnetic flux at the fixing portion, and to improve the shielding performance. The effect is obtained. The shield performance can be further improved by forming the washer used when assembling the magnetic shield room with a high-permeability alloy.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of a magnetic shield room according to a preferred embodiment of the present invention.

FIG. 2 is a schematic perspective view showing a corner portion of a magnetic shield room and a second shielding member according to the embodiment.

FIG. 3 is an explanatory diagram illustrating a flow of a magnetic flux in a corner of a magnetically shielded room according to the embodiment.

FIG. 4 is an explanatory diagram illustrating an arrangement state of a third shielding member on a wall surface of the magnetically shielded room according to the embodiment.

FIG. 5 is an enlarged explanatory view of a main part showing a relationship between a third shielding member and a wall butting portion according to the embodiment.

FIG. 6 is a cross-sectional view illustrating a fixing portion between a third shielding member and a plate member according to the embodiment.

[Explanation of symbols]

 14 plate material 16 first shielding member 18 second shielding member 20 third shielding member 22 corner butting portion 24 corner butting portion 26 wall butting portion 28 washer

Claims (4)

[Claims] A plurality of plates (1) made of a high-permeability alloy.
4) in a magnetically shielded room assembled by arranging the edges thereof to abut each other.
At the corner where the corner of 4) abuts at a predetermined angle, each plate material (14)
A magnetically shielded room characterized in that a cap-shaped shielding member (18) made of a high-permeability alloy having three surfaces in contact with a member is disposed so as to cover the butted portion (24) at the corner. 2. A plurality of plates (1) made of a high-permeability alloy.
4), in a magnetically shielded room assembled by arranging the edges thereof to face each other, in such a manner that the corners of the three or more plate members (14) cover portions where the corners of the plate members (14) abut each other in the same plane. In addition, a shielding member made of a high permeability alloy (20)
And all the plate members (14) constituting the butted portion (26)
A magnetically shielded room that is arranged so as to be in contact with the room. 3. A plurality of plates (1) made of a high-permeability alloy.
4), in a magnetically shielded room assembled by arranging its edges to abut each other, a high magnetic permeability alloy covering the abutting portion (22, 24, 26) of each of the plate members (14) is used as a material. A magnetic shield room, wherein the shielding members (16, 18, 20) are screwed using washers (28) of the same material as the shielding members (16, 18, 20). 4. A member (14, 16, 1) made of a high permeability alloy material.
A magnetically shielded room, characterized in that 8,8) are screwed using a washer (28) made of a high magnetic permeability alloy.