JP7079481B2 - Magnetic shield room - Google Patents

Description

The present invention relates to a magnetically shielded room that shields an electromagnetic field from the outside, and more particularly to a box-shaped magnetically shielded room having a permalloy inner wall and a copper outer wall.

For example, when performing biomagnetic measurement such as MRI and cerebral porcelain, and other precise measurements, a magnetic shield room is used so that the surrounding electric field, magnetic field, or the like does not affect the inspection or measurement. This type of magnetically shielded room includes, for example, a closed room in which a floor, a ceiling, a side wall, etc. are made of a plate made of a high magnetic permeability material such as permalloy, and a conductive room such as copper or aluminum that surrounds the closed room. It includes a coil made of a sex material (see Patent Document 1).

In this magnetically shielded room, a plate material such as permalloy is abutted against each other to form a closed state, thereby shielding the intrusion of a magnetic field from the outside into the closed room. The coil surrounding the closed room generates an overcurrent by electromagnetic induction when the magnetism enters the closed room, and acts to cancel the entering magnetism. Therefore, the influence of the magnetic field from the outside is reduced inside the coil, and the shielding effect of the magnetic field is improved. In addition, high magnetic permeability materials such as permalloy are effective for low frequency magnetism, and conductive materials such as copper and aluminum are effective for high frequency magnetism, so they effectively shield both low frequency and high frequency magnetism. be able to.

In the case of this kind of magnetic shield room, in the case of medical or industrial use, it is a relatively large facility, so construction such as assembly is performed at the installation site. At that time, the butting of the plate materials such as permalloy constituting the closed room is generally required to have high closing property, and therefore welding is generally performed. However, welding produces a large amount of smoke during work. Therefore, for example, depending on the construction site such as a hospital, it may be necessary to avoid the generation of smoke during work due to the site environment and the like, and it may not be possible to assemble at the site. In addition, the construction tools used for welding, coil installation, etc. are large-scale, and there is a problem that the work becomes complicated.

Japanese Patent Application Laid-Open No. 2003-273566

The present invention has been made in view of the above points, and provides a magnetically shielded room in which workability during construction is improved while sufficiently ensuring a magnetic shielding effect.

That is, the invention of claim 1 is a box-shaped magnetic shield chamber provided with an inner wall made of permalloy and an outer wall made of copper, wherein the inner wall is composed of a skeleton member and a plate-shaped object made of permalloy, and the skeleton member. Made of Permalloy, which connects a plurality of inner wall plate members that are overlapped and arranged in a butt state on the outside of the above, and the adjacent inner wall plate members that are erected on the outside of the butt portion of the adjacent inner wall plate members and are connected to each other . The skeleton member has a plurality of skeleton screw holes, and the inner wall plate member corresponds to the plurality of skeleton screw holes of the skeleton member at the outer edge portion. The inner wall plate connecting member has a plurality of inner wall plate screw hole portions, and the inner wall plate connecting member is adjacent to a plurality of first inner wall plate connecting screw hole portions corresponding to the plurality of inner wall plate screw hole portions of one adjacent inner wall plate member. It has a plurality of second inner wall plate connecting screw holes corresponding to a plurality of inner wall plate screw holes of other matching inner wall plate members, and the inner wall plate connecting member, the inner wall plate member, and the skeleton member are the skeleton. The screw hole portion, the inner wall plate screw hole portion, and the first inner wall plate connecting screw hole portion or the second inner wall plate connecting screw hole portion are threaded and fixed via an inner wall screw hole portion formed by communicating with each other. The outer wall is composed of a square tubular support member arranged on the outside of the inner wall and a plurality of outer wall plate members made of a copper plate-like material and overlapped on the outside of the support member and arranged in a butt state. It has an outer wall plate connecting member made of a copper plate that is erected on the outside of the abutting portion between the adjacent outer wall plate members and connects the adjacent outer wall plate members to each other. Is a plurality of operations through which a plurality of inner strut screw holes formed on the inner side surface and a screw member screwed into the inner strut screw hole portion facing the inner strut screw hole portion on the outer surface can be inserted. The outer wall plate member has a hole portion and a plurality of first outer strut screw holes and a second outer strut screw hole portion, and the outer wall plate member has the first outer strut screw hole portion of the strut member or the first outer strut screw hole portion at the outer edge portion. The outer wall plate connecting member has a plurality of outer wall plate screw holes corresponding to the second outer strut screw holes, and the outer wall plate connecting member is a plurality of first outer wall plates corresponding to the outer wall plate screw holes of one adjacent outer wall plate member. It has a connecting screw hole portion and a plurality of second outer wall plate connecting screw hole portions corresponding to the outer wall plate screw hole portions of other adjacent outer wall plate members, and has the outer wall plate connecting member, the outer wall plate member, and the support column. The member includes the first outer strut screw hole portion, the outer wall plate screw hole portion, the first outer wall plate connecting screw hole portion, or the second outer strut screw hole portion, the outer wall plate screw hole portion, and the second outer wall. Communication with the plate connecting screw hole The inner wall and the outer wall are screwed and fixed via the outer wall screw hole portion formed in the slab, and the inner wall and the outer wall are the skeleton screw hole portion, the inner wall plate screw hole portion, and the first inner wall plate constituting the inner wall screw hole portion. The magnetic feature is that the connecting screw hole portion or the second inner wall plate connecting screw hole portion and the inner strut screw hole portion formed on the inner side surface of the strut member are communicated and integrally screwed and fixed. Related to the shield room.

The invention according to claim 2 relates to the magnetic shield room according to claim 1 , wherein the working hole portion of the strut member is formed so that a screw member screwed into the inner strut screw hole portion can be inserted.

The invention of claim 3 relates to the magnetic shield room according to claim 1 or 2 , wherein the reinforcing plate is arranged on the inner surface side of the outer wall plate member.

According to the magnetic shield room according to the invention of claim 1, it is a box-shaped magnetic shield room provided with an inner wall made of permalloy and an outer wall made of copper, and the inner wall is made of a skeleton member and a plate-shaped object made of permalloy. The inner wall plate members that are overlapped on the outside of the skeleton member and arranged in a butt state, and the inner wall plate members that are erected on the outside of the butt portion of the adjacent inner wall plate members and adjacent to each other. It has an inner wall plate connecting member made of a plate-shaped material made of Permalloy to be connected, the skeleton member has a plurality of skeleton screw holes, and the inner wall plate member has a plurality of the skeleton screws of the skeleton member at an outer edge portion. The inner wall plate connecting member has a plurality of inner wall plate screw holes corresponding to the holes, and the inner wall plate connecting member has a plurality of first inner wall plate connecting screw holes corresponding to the plurality of inner wall plate screw holes of one adjacent inner wall plate member. It has a portion and a plurality of second inner wall plate connecting screw hole portions corresponding to a plurality of inner wall plate screw hole portions of other adjacent inner wall plate members, and has the inner wall plate connecting member, the inner wall plate member, and the skeleton member. Is via an inner wall screw hole portion formed by communicating the skeleton screw hole portion, the inner wall plate screw hole portion, the first inner wall plate connecting screw hole portion, or the second inner wall plate connecting screw hole portion. The outer wall was screwed and fixed, and the outer wall was made of a square tubular support member arranged on the outside of the inner wall and a copper plate-like material, and was overlapped on the outside of the support member and arranged in a butt state. It has an outer wall plate member and an outer wall plate connecting member made of a copper plate that is erected on the outside of the abutting portion between the adjacent outer wall plate members and connects the adjacent outer wall plate members . In the strut member, a plurality of inner strut screw holes formed on the inner side surface and a screw member screwed into the inner strut screw hole portion facing the inner strut screw hole portion on the outer surface can be inserted. It has a plurality of working holes and a plurality of first outer strut screw holes and a second outer strut screw hole portion, and the outer wall plate member has the first outer strut screw of the strut member at an outer edge portion. The outer wall plate connecting member has a plurality of outer wall plate screw holes corresponding to the holes or the second outer strut screw holes, and the outer wall plate connecting member has a plurality of outer wall plate screw holes corresponding to one adjacent outer wall plate member. It has a first outer wall plate connecting screw hole portion and a plurality of second outer wall plate connecting screw hole portions corresponding to the outer wall plate screw hole portions of other adjacent outer wall plate members, and has the outer wall plate connecting member and the outer wall plate. The member and the strut member include the first outer strut screw hole portion, the outer wall plate screw hole portion, the first outer wall plate connecting screw hole portion, or the second outer strut screw hole portion and the outer wall plate screw hole portion. The second outer wall plate series The inner wall and the outer wall are screwed and fixed via the outer wall screw hole portion formed by communicating the binding screw hole portion, and the inner wall and the outer wall are the skeleton screw hole portion and the inner wall plate screw hole constituting the inner wall screw hole portion. The portion, the first inner wall plate connecting screw hole portion or the second inner wall plate connecting screw hole portion, and the inner strut screw hole portion formed on the inner side surface of the strut member are communicated and integrally screwed and fixed. Therefore, the structure of each member is simple and can be easily assembled without using welding while sufficiently ensuring the magnetic shielding effect, and the workability at the time of construction is greatly improved.

According to the magnetic shield room according to the invention of claim 2 , in the invention of claim 1 , the working hole portion of the strut member is formed so that the screw member screwed to the inner strut screw hole portion can be inserted. Therefore, the work such as screwing and removing the screw member becomes easy, and the workability is improved.

According to the magnetic shield room according to the invention of claim 3 , in the invention of claim 1 or 2 , since the reinforcing plate is arranged on the inner surface side of the outer wall plate member, the outer wall plate member can be made thinner. Therefore, the manufacturing cost can be reduced.

It is an overall perspective view of the magnetic shield room which concerns on one Embodiment of this invention. It is the whole perspective view of the magnetic shield room which shows the state which the support column member is arranged on the inner wall. It is sectional drawing of the main part of a magnetic shield room. It is an exploded perspective view of the main part of the inner wall. It is an exploded perspective view of the main part of the outer wall.

FIGS. 1 and 2 show a magnetically shielded room 1 according to an embodiment of the present invention, which includes an inner wall 10 made of permalloy and an outer wall 50 made of copper. The magnetic shield room 1 is formed in a box shape having a polyhedral shape such as a cube or a rectangular parallelepiped, a cylindrical shape, or the like. The magnetic shield room 1 is suitably used as a closed space for medical use, experimentation, and industrial use for shielding magnetism from the outside, such as MRI, biomagnetic measurement such as a cerebral magnetometer, other precision measurement, and semiconductor manufacturing. ..

In the magnetic shield room 1 of the present invention, as shown in FIGS. It is erected by 40, and the inner wall plate connecting member 40, the inner wall plate member 30, and the skeleton member 20 are screwed through the inner wall screw hole portion 15 formed by communicating the inner wall plate connecting member 40, the inner wall plate member 30, and the skeleton member 20. The outer wall 50 is fixed by wearing, and a plurality of support members 60 and outer wall plate members 70 arranged on the outside of the inner wall 10 are arranged, and adjacent outer wall plate members 70 and 70 are erected by the outer wall plate connecting member 90. The outer wall plate connecting member 90, the outer wall plate member 70, and the strut member 60 are screwed together via the outer wall screw hole portion 55 formed by communicating with the outer wall plate connecting member 90, the outer wall plate member 70, and the outer surface of the strut member 60. The inner wall 10 and the outer wall 50 are integrally screwed and fixed via the inner strut screw hole portion 65 and the inner wall screw hole portion 15 formed on the inner side surface of the strut member 60. In FIGS. 1 and 2, the screwed portions of the inner wall 10 and the outer wall 50 are omitted.

The inner wall 10 is a closed room formed in a box shape to shield magnetism from the outside, and as shown in FIGS. 3 and 4, the skeleton member 20, the inner wall plate member 30, and the inner wall plate connecting member 40. And have. The skeleton member 20 is a member corresponding to a pillar, a beam, or the like that defines the shape of the inner wall 10 that is a closed room, and is made of a high-strength material such as aluminum. In the skeleton member 20 of the embodiment, a plurality of frame body portions 21 having substantially the same shape as the inner wall plate member 30 described later are arranged so as to form a box-shaped frame. The frame body portion 21 constituting the skeleton member 20 has a plurality of skeleton screw hole portions 25 provided in series over the entire surface. Although the spacing between the plurality of skeleton screw hole portions 25 is appropriate, they are formed at relatively short spacing of about 50 to 100 mm from the viewpoint of workability and the closing property of the inner wall plate member 30 described later.

The inner wall plate member 30 is made of a plate-shaped material made of permalloy, and as shown in FIGS. It constitutes the ceiling and side walls. The shape and size of the inner wall plate member 30 are determined according to the application, the manufacturing cost, and the like. For example, the plate thickness is about 1 to 2 mm, and the length is 1200 mm and the width is 600 mm, or the length is 1200 mm and the width is 700 mm. The inner wall plate member 30 of the embodiment is arranged corresponding to one frame body portion 21 of the skeleton member 20, and a plurality of skeletons formed on the frame body portion 21 of the skeleton member 20 at the outer edge portion. It has a plurality of inner wall plate screw hole portions 35 corresponding to the screw hole portions 25. That is, the plurality of inner wall plate screw hole portions 35 are formed at the same intervals so as to communicate with each skeleton screw hole portion 25 when the inner wall plate member 30 is superposed on the frame body portion 21 of the skeleton member 20. ..

The inner wall plate connecting member 40 is made of a plate-shaped material made of permalloy, and as shown in FIGS. 1 to 4, a plurality of inner wall plate members 30 and 30 adjacent to each other in a butt state are arranged to connect the two. The shape of the inner wall plate connecting member 40 is determined according to the positional relationship between the adjacent inner wall plate members 30, 30. That is, when the two inner wall plate members 30 and 30 are adjacent to each other on the side surface of the inner wall 10 flush with each other, the inner wall plate connecting member 40 is the first inner wall plate connecting member 41 formed in a flat plate shape, and is the inner wall 10. The inner wall plate connecting member 40 when the two inner wall plate members 30 and 30 are adjacent to each other at a substantially right angle on the side portion is a second inner wall plate connecting member 42 or the like formed in a substantially L-shape in the side view.

As shown in FIG. 3, the inner wall plate connecting member 40 of the embodiment is adjacent to a plurality of first inner wall plate connecting screw hole portions 45 corresponding to the inner wall plate screw hole portions 35a of one adjacent inner wall plate member 30A. It has a plurality of second inner wall plate connecting screw hole portions 46 corresponding to the inner wall plate screw hole portions 35b of the other inner wall plate member 30B. The plurality of first inner wall plate connecting screw hole portions 45 and the second inner wall plate connecting screw hole portions 46 are formed at the same intervals as the inner wall plate screw hole portions 35 of the inner wall plate member 30, and each inner wall of the inner wall plate member 30 is formed. It communicates with the plate screw hole portion 35.

In the inner wall 10, as shown in FIG. 3, the skeleton screw hole portion 25 of the skeleton member 20, the inner wall plate screw hole portion 35 of the inner wall plate member 30, and the first inner wall plate connecting screw hole portion 45 of the inner wall plate connecting member 40. Alternatively, the inner wall plate connecting screw hole portion 46 communicates with the second inner wall plate connecting screw hole portion 46 to form the inner wall screw hole portion 15. The inner wall 10 has a plurality of inner wall screw hole portions 15 composed of the skeleton screw hole portion 25, the inner wall plate screw hole portion 35, the first inner wall plate connecting screw hole portion 45, or the second inner wall plate connecting screw hole portion 46. It is screwed and fixed through.

In this way, the adjacent inner wall plate members 30 and 30 are closed by the inner wall plate connecting member 40 being erected at the abutting portion, and the inner wall is made of the same material as permalloy. It is connected via the plate connecting member 40. Therefore, the magnetic flux flows between the plurality of inner wall plate members 30, 30 and shields the entry into the inner wall 10. Further, since the skeleton member 20 and the inner wall plate member 30 are integrally screwed and fixed via the inner wall plate connecting member 40, welding is not required at the time of assembly. As shown in FIG. 3, the skeleton member 20, the inner wall plate member 30, and the inner wall plate connecting member 40 are screwed and fixed by a single inner wall screw member made of a non-magnetic material such as brass or stainless steel (SUS). Since it is performed by 16, the influence of the magnetic field does not occur at the screwed portion.

As shown in FIGS. 3 and 5, the outer wall 50 is arranged so as to surround the inner wall 10, and has a support column member 60, an outer wall plate member 70, and an outer wall plate connecting member 90. A plurality of support column members 60 are arranged on the outside of the inner wall 10 and are square tubular members for attaching the outer wall 50 to the inner wall 10, and are made of a high-strength material such as aluminum. The spacing between the plurality of column members 60 corresponds to the shape of the outer wall plate member 70 described later. The strut member 60 of the embodiment has a plurality of inner strut screw hole portions 65 formed on the inner side surface 61, a plurality of work hole portions 66 on the outer surface 62, and a plurality of first outer strut screw hole portions 67 and a first. 2 It has an outer strut screw hole portion 68.

The inner strut screw hole portions 65 are formed at the same intervals corresponding to the inner wall plate screw hole portions 35 formed in the inner wall plate member 30. The work hole portion 66 is arranged so as to face each inner strut screw hole portion 65 formed on the inner side surface 61 so that a screw member screwed into the inner strut screw hole portion 65 can be inserted. It is formed to have a diameter larger than that of the inner strut screw hole portion 65. Therefore, work such as screwing and removing the inner wall screw member 16 becomes easy, and workability is improved. A plurality of first outer strut screw hole portions 67 and second outer strut screw hole portions 68 are provided symmetrically in series on the outer surface 62. Although the spacing between the plurality of first outer strut screw hole portions 67 and the second outer strut screw hole portions 68 is appropriate, it is relatively about 50 to 100 mm from the viewpoint of workability and the closing property of the outer wall plate member 70 described later. Formed at short intervals.

The outer wall plate member 70 is made of a copper plate-like material, and as shown in FIGS. Siege. The outer wall plate member 70 acts like a coil by being arranged so as to surround the inner wall 10. When the outer wall 50 surrounding the inner wall 10 is formed, it is preferable that the corners of the outer wall 50 are formed by bending the outer wall plate member 70 in order to improve the closing property of the outer wall 50. Further, the thicker the outer wall plate member 70 is, the higher the shielding effect of the magnetic field is. However, since the outer wall plate member 70 is a copper plate-like material, the manufacturing cost increases as the wall thickness increases. Therefore, from the viewpoint of the shielding effect, the manufacturing cost, and the like, the thickness of the outer wall plate member 70 is preferably about 1 to 5 mm. The shape and size of the outer wall plate member 70 are determined according to the intended use and the like, and are, for example, 2000 mm in length and 1000 mm in width. The outer wall plate member 70 of the embodiment has a plurality of outer wall plate screw hole portions 75 corresponding to a plurality of first outer strut screw hole portions 67 or a second outer strut screw hole portion 68 of the strut member 60 at both side edge portions. It is arranged between the two support column members 60, 60. That is, the plurality of outer wall plate screw hole portions 75 are formed at the same intervals so as to communicate with the first outer strut screw hole portion 67 or the second outer strut screw hole portion 68.

It is conceivable that the outer wall plate member 70 is made of an aluminum plate-like material, which is the same conductive material, instead of the copper plate-like material. However, in the case of an aluminum plate-shaped material, an oxide film (alumina) may be formed on the surface of the aluminum plate-shaped material when the aluminum plate-shaped material is screwed and fixed, and the magnetic field shielding effect may be reduced. Therefore, when comparing a copper plate and an aluminum plate having the same thickness, the copper plate has a better shielding effect. Therefore, it is preferable to use a copper plate-like material for the outer wall plate member 70.

In the outer wall plate member 70, as shown in FIG. 3, a reinforcing plate 80 is arranged on the inner surface side as needed. The reinforcing plate 80 is made of a plate material of a conductive material such as aluminum. The reinforcing plate 80 is formed to have the same thickness as the outer wall plate member 70, and has a plurality of reinforcing plate screw hole portions 85 communicating with the plurality of outer wall plate screw hole portions 75 of the outer wall plate member 70 at the side edge portion. The reinforcing plate 80 retains the shape of the outer wall plate member 70 by being arranged on the outer wall plate member 70. Therefore, the outer wall plate member 70, which is a copper plate, can be made thinner, and the manufacturing cost can be reduced.

The outer wall plate connecting member 90 is made of a copper plate, and as shown in FIGS. 1 to 3 and 5, a plurality of outer wall plate members 70 and 70 adjacent to each other in a butt state are arranged to connect the two. The outer wall plate connecting member 90 of the embodiment is a plurality of first outer wall plate connecting screw hole portions 95 corresponding to the outer wall plate screw hole portions 75a of one adjacent outer wall plate member 70A, and another outer wall plate member 70B adjacent to each other. It has a plurality of second outer wall plate connecting screw hole portions 96 corresponding to the outer wall plate screw hole portion 75b. The plurality of first outer wall plate connecting screw hole portions 95 and the second outer wall plate connecting screw hole portion 96 are formed at the same intervals as the outer wall plate screw hole portions 75 of the outer wall plate member 70, and each outer wall of the outer wall plate member 70 is formed. It communicates with the plate screw hole portion 75.

In the outer wall 50, as shown in FIG. 3, the first outer strut screw hole portion 67 of the strut member 60, the outer wall plate screw hole portion 75 of the outer wall plate member 70, and the first outer wall plate connecting screw of the outer wall plate connecting member 90. The hole portion 95 or the second outer strut screw hole portion 68 of the strut member 60, the outer wall plate screw hole portion 75 of the outer wall plate member 70, and the second outer wall plate connecting screw hole portion 96 of the outer wall plate connecting member 90 communicate with each other. Then, the outer wall screw hole portion 55 is formed. The outer wall 50 includes the first outer strut screw hole portion 67, the outer wall plate screw hole portion 75, the first outer wall plate connecting screw hole portion 95, or the second outer strut screw hole portion 68, the outer wall plate screw hole portion 75, and the second. It is screwed and fixed via a plurality of outer wall screw hole portions 55 composed of the outer wall plate connecting screw hole portions 96.

In this way, the adjacent outer wall plate members 70, 70 are closed by closing the gap by installing the outer wall plate connecting member 90 at the abutting portion, and the outer wall made of copper of the same material is used. It is connected via the plate connecting member 90. Therefore, the current can flow between the plurality of outer wall plate members 70, 70 over the entire circumference, and the magnetism that enters due to the overcurrent generated by electromagnetic induction can be canceled like the coil. Further, since the support column member 60 and the outer wall plate member 70 are integrally screwed and fixed via the outer wall plate connecting member 90, welding is not required at the time of assembly. As shown in FIG. 3, the strut member 60, the outer wall plate member 70, and the outer wall plate connecting member 90 are screwed and fixed by a single outer wall screw member made of a non-magnetic material such as brass or stainless steel (SUS). Since it is performed by 56, the influence of the magnetic field does not occur at the screwed portion.

Since the inner wall 10 and the outer wall 50 are both screwed and fixed by screw members without welding, the influence on the construction site such as smoke generated during work is greatly reduced, and the construction tools can be used. It is simplified and the work load is reduced. Further, in the inner wall 10 and the outer wall 50, the skeleton screw hole portion 25, the inner wall plate screw hole portion 35, the first inner wall plate connecting screw hole portion 45, or the second inner wall plate connecting screw hole constituting the inner wall screw hole portion 15 of the inner wall 10 are formed. The portion 46 and the inner strut screw hole portion 65 formed on the inner surface of the strut member 60 communicate with each other and are integrally screwed and fixed. That is, the outer wall 50 is attached to the inner wall 10 by utilizing the inner wall screw hole portion 15 used for screwing and fixing each member of the inner wall 10. Therefore, complicated members and the like are not required to attach the outer wall 50, and the construction can be easily performed.

Next, the magnetically shielded rooms of Prototype Examples 1 to 6 were produced under the following conditions.

[Prototype example 1]
As the inner wall plate member, four permalloy plates having a length of 1200 mm, a width of 350 mm, and a thickness of 1 mm and two permalloy plates having a length of 350 mm, a width of 350 mm, and a thickness of 1 mm are prepared, and the inner wall plate connecting member is vertically formed. A required number of Permalloy plates with a thickness of 1200 mm, a width of 100 mm, and a thickness of 1 mm were prepared. In the magnetic shield room of Prototype Example 1, these plate materials were assembled to form a box-shaped inner wall having a width of 350 mm, a depth of 350 mm, and a height of 1200 mm, and no outer wall was attached.

[Prototype example 2]
As the outer wall plate member, a copper plate material having a length of 1200 mm, a width of 1520 mm, and a thickness of 1 mm was prepared. The magnetic shield room of Prototype Example 2 is formed by bending a copper plate material into a substantially square cylinder having a base of 380 mm and a height of 1200 mm, and arranging the copper plate material around the inner wall of Prototype Example 1 and bending the copper plate material. A gap of 10 mm was provided on the end side to form an outer wall.

[Prototype example 3]
A copper plate having a length of 1200 mm, a width of 100 mm, and a thickness of 5 mm was prepared as an outer wall plate connecting member. In the magnetic shield room of Prototype Example 3, a copper outer wall plate connecting member is arranged on the end side of the outer wall of Prototype Example 2, and screwed and fixed at 100 mm intervals using a screw member made of SUS to cover the entire circumference of the inner wall. Surrounded over the circumference.

[Prototype Example 4]
The magnetic shield room of Prototype Example 4 has the same configuration except for the interval of screwing and fixing of Prototype Example 3 at an interval of 200 mm.

[Prototype Example 5]
For the magnetic shield room of Prototype Example 5, instead of the copper outer wall plate connecting member of Prototype Example 3, an aluminum plate material having a length of 1200 mm, a width of 100 mm, and a thickness of 1 mm is prepared, and SUS screw members are used at intervals of 100 mm. It was screwed and fixed with, and the circumference of the inner wall was surrounded all around.

[Prototype Example 6]
In the magnetic shield room of Prototype Example 6, the edges of the outer wall of Prototype Example 2 were welded to surround the inner wall over the entire circumference.

For the magnetically shielded rooms of Prototype Examples 1 to 6, the external magnetic field and the internal magnetic field were measured, and the shield ratio was obtained. For the measurement of the external magnetic field and the internal magnetic field, a coil is provided around the magnetic shield room to measure the magnetic field generated by energization (external magnetic field) with a known magnetic sensor, and the magnetic field in the magnetic shield room at that time (internal). The magnetic field) is measured by a known magnetic sensor installed in the magnetic shield room. The shield ratio is obtained from the ratio of the internal magnetic field to the external magnetic field measured in this way (shield ratio = external magnetic field ÷ internal magnetic field). The higher the shield ratio, the higher the magnetic shielding effect. Tables 1 and 2 show the results of changes in the internal magnetic field strength (μT) and the shield ratio for each external magnetic field strength (μT) generated in response to the frequency (Hz) when energized.

As can be understood from Tables 1 and 2, Prototype Example 1 having no outer wall had a significantly lower shield ratio than the other Prototype Examples 2 to 6 having an outer wall. Further, in the prototype examples 2 to 6 having an outer wall, the shield ratio of the prototype example 2 in which the gap was formed in the outer wall was lower than that of the other prototype examples 3 to 6. Therefore, it is effective to arrange the outer wall without a gap so as to surround the inner wall.

Next, in Prototype Examples 3 to 6 in which the outer walls are arranged without gaps, in Prototype Example 5 in which the copper outer wall plate member is screwed and fixed using the aluminum outer wall plate connecting member, the outer wall is entirely made of copper. The shield ratio was lower than that of the prototype examples 3, 4, and 6. Therefore, it was found that it is more effective to screw and fix with the outer wall plate connecting member of the same material than when screwing and fixing using the outer wall plate connecting member of the same material as the copper outer wall plate member.

Prototype examples 3, 4, and 6 in which the outer wall was made of copper all had a high shielding rate. In particular, Prototype Example 3 in which the spacing between the screw members is 100 mm has a higher value than Prototype Example 4 in which the spacing between the screw members is 200 mm, and a shield ratio comparable to that of the welded Prototype Example 6 was obtained. Therefore, it was found that the shorter the spacing between the screw members when screwing and fixing, the more effective it is, and if the spacing is about 100 mm, the same effect as in the case of welding can be obtained.

As illustrated and explained above, in the magnetic shield room of the present invention, the skeleton member constituting the inner wall, the inner wall plate member, and the inner wall plate connecting member are screwed through the inner wall screw hole portion formed by communicating with each member. At the same time as being fixed by welding, the support member constituting the outer wall, the outer wall plate member, and the outer wall connecting member are screwed and fixed via the outer wall screw hole portion formed by communicating with each member, and the inner wall and the outer wall are formed of the support member. Since it is integrally screwed and fixed via the inner strut screw hole portion and the inner wall screw hole portion formed on the inner side surface, welding at the time of assembly becomes unnecessary. Therefore, smoke is not generated during work, assembly is easy, construction tools are simplified, and the influence on the vicinity of the construction site and the burden of work are greatly reduced. Then, the inner wall plate member made of Permalloy is screwed and fixed via the inner wall plate connecting member made of the same material to form the inner wall, and the copper outer wall plate member is made of the same material as the copper outer wall plate connecting member. By being screwed and fixed through the wall to form the outer wall, an excellent shielding effect comparable to that when the inner wall and the outer wall are welded can be obtained.

Further, in the magnetic shield room of the present invention, the skeleton screw hole portion of the skeleton member, the inner wall plate screw hole portion of the inner wall plate member, the first inner wall plate connecting screw hole portion of the inner wall plate connecting member, or the second inner wall plate connecting screw hole portion. The strut member has an inner strut screw hole portion on the inner side surface and a work hole portion facing the inner strut screw hole portion on the outer surface, and a plurality of first outer strut parts. It has a screw hole portion and a second outer strut screw hole portion, and has a first outer strut screw hole portion of the strut member, an outer wall plate screw hole portion of the outer wall plate member, and a first outer wall plate connecting screw hole portion of the outer wall plate connecting member. Or, because the screw hole portion of the second outer strut, the screw hole portion of the outer wall plate of the outer wall plate member, and the second outer wall plate connecting screw hole portion of the outer wall plate connecting member communicate with each other to form the outer wall screw hole portion. The structure is simple and easy to assemble, and workability is further improved.

As described above, the magnetic shield room of the present invention can be easily assembled without using welding while sufficiently ensuring the magnetic shielding effect, so that the influence on the vicinity of the construction site is reduced. Therefore, it is a promising alternative to the conventional magnetic shield room.

1 Magnetic shield room 10 Inner wall 15 Inner wall screw hole 16 Inner wall screw member 20 Skeletal member 21 Frame body 25 Skeletal screw hole 30, 30A, 30B Inner wall plate member 35, 35a, 35b Inner wall plate screw hole 40 Inner wall plate connecting member 41 1st inner wall plate connecting member 42 2nd inner wall plate connecting member 45 1st inner wall plate connecting screw hole part 46 2nd inner wall plate connecting screw hole part 50 outer wall 55 outer wall screw hole part 56 outer wall screw member 60 strut member 61 inner side surface 62 Outer side surface 65 Inner strut screw hole 66 Work hole 67 First outer strut screw hole 68 Second outer strut screw hole 70, 70A, 70B Outer wall plate member 75, 75a, 75b Outer wall plate screw hole 80 Reinforcing plate 85 Reinforcing plate screw hole 90 Outer wall plate connecting member 95 First outer wall plate connecting screw hole 96 Second outer wall plate connecting screw hole

Claims (3)

A box-shaped magnetically shielded room with a permalloy inner wall and a copper outer wall.
The inner wall is made of a skeleton member and a plate-shaped material made of permalloy, and a plurality of inner wall plate members are arranged so as to be overlapped on the outside of the skeleton member in a butt state, and the outside of a butt portion between adjacent inner wall plate members. It has an inner wall plate connecting member made of a plate-shaped material made of permalloy, which is erected on top of each other and connects the adjacent inner wall plate members to each other .
The skeleton member has a plurality of skeletal screw holes and has a plurality of skeletal screw holes.
The inner wall plate member has a plurality of inner wall plate screw hole portions corresponding to the plurality of skeleton screw hole portions of the skeleton member at the outer edge portion.
The inner wall plate connecting member includes a plurality of first inner wall plate connecting screw holes corresponding to a plurality of inner wall plate screw holes of one adjacent inner wall plate member, and a plurality of inner wall plate screws of other adjacent inner wall plate members. It has a plurality of second inner wall plate connecting screw holes corresponding to the holes, and has a plurality of second inner wall plate connecting screw holes.
The inner wall plate connecting member, the inner wall plate member, and the skeleton member are the skeleton screw hole portion, the inner wall plate screw hole portion, the first inner wall plate connecting screw hole portion, or the second inner wall plate connecting screw hole portion. It is screwed and fixed through the inner wall screw hole formed by communicating with and.
The outer wall is adjacent to a square tubular support member arranged on the outside of the inner wall and an outer wall plate member made of a copper plate and arranged on the outside of the support member in a butted state. It has an outer wall plate connecting member made of a copper plate that is erected on the outside of the abutting portion of the matching outer wall plate members and connects the adjacent outer wall plate members to each other .
The strut member can be inserted with a plurality of inner strut screw holes formed on the inner side surface and a screw member screwed to the inner strut screw hole portion on the outer surface facing the inner strut screw hole portion. It has a plurality of work holes and a plurality of first outer strut screw holes and a second outer strut screw hole.
The outer wall plate member has a plurality of outer wall plate screw hole portions corresponding to the first outer strut screw hole portion or the second outer strut screw hole portion of the strut member at the outer edge portion.
The outer wall plate connecting member corresponds to a plurality of first outer wall plate connecting screw holes corresponding to the outer wall plate screw holes of one adjacent outer wall plate member and the outer wall plate screw holes of other adjacent outer wall plate members. It has a plurality of second outer wall plate connecting screw holes and
The outer wall plate connecting member, the outer wall plate member, and the strut member are the first outer strut screw hole portion, the outer wall plate screw hole portion, the first outer wall plate connecting screw hole portion, or the second outer strut screw hole. The portion, the outer wall plate screw hole portion, and the second outer wall plate connecting screw hole portion are threaded and fixed via the outer wall screw hole portion formed by communicating with each other.
The inner wall and the outer wall are the skeleton screw hole portion constituting the inner wall screw hole portion, the inner wall plate screw hole portion, the first inner wall plate connecting screw hole portion, or the second inner wall plate connecting screw hole portion, and the above. A magnetic shield room characterized in that the screw holes of the inner strut formed on the inner surface of the strut member are communicated with each other and integrally screwed and fixed. The magnetic shield room according to claim 1, wherein the work hole portion of the strut member is formed so that a screw member screwed into the inner strut screw hole portion can be inserted. The magnetic shield room according to claim 1 or 2, wherein a reinforcing plate is arranged on the inner surface side of the outer wall plate member.

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