JP2725248B2 - Panel for electromagnetic shielding - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Purpose) The present invention relates to a panel for an electromagnetically shielded room.

Recently, the importance of preventing malfunctions and measurement errors due to electromagnetic waves and magnetism of precision electronic and electrical equipment such as medical equipment and OA equipment has been emphasized, and construction of shield rooms has been increasing.

However, when applying an electromagnetic wave shield, a high-conductivity material such as aluminum or copper is used because an electric field component in a high-frequency region is mainly used.However, in a magnetic field shield, a magnetic field component in a low-frequency region is mainly used. High permeability materials such as amorphous metal and permalloy were used, and were treated completely differently from electromagnetic wave shields.

In particular, in MRI and computer rooms, consideration should be given to the pacemaker owner (5G or less), shielding of magnetic fields up to the limit that does not cause computer malfunction (0.5G or less), and the effects of electromagnetic waves (for example, in the case of MRI Is 1
It is necessary to provide a shield so that misdiagnosis does not occur at ~ 100M Hz), but until now, separate construction for magnetic field and electric field has increased the cost.

Next, as a construction method of these magnetic or electromagnetic shield rooms, a partition construction to be stretched on a frame is mainly performed. In other words, the frame is composed of a lightweight steel frame or wood,
On top of that, a plywood or concrete panel is stuck, and the shielding material (copper aluminum for electric field, amorphous, permalloy for magnetic field) is fixed, and then plywood or concrete panel for finishing is fixed. After construction and seaming, the finish is achieved by painting, requiring considerable man-hours and increasing costs.

An object of the present invention is to solve the above-mentioned problems of the related art and to provide a shield material that can be easily installed.

(Structure) In order to solve the above-described problems, the present invention provides a rectangular frame formed of an L-shaped angle or a pipe, an iron plate, a silicon steel plate, an aluminum plate, or a copper plate disposed on the frame, and an end thereof. Portion has a box shape bent 90 ° along the L-angle and the pipe, and further has a soft magnetic amorphous alloy portion disposed thereon, and the amorphous alloy portion has a thickness of 5 mm. ~ 100μ
It has a structure in which flake-shaped soft magnetic amorphous alloy pieces with an aspect ratio of 10 to 15,000 are laminated, and provides an electromagnetic shield panel that abuts the bent parts of adjacent panels and connects and fixes them with bolts and nuts. I do.

When applying electromagnetic wave shielding, the use of a highly conductive material such as aluminum or copper can significantly improve the shielding ratio.However, if the shielding ratio is a certain level, a magnetic material such as iron, silicon steel, etc. is sufficient for connection. If possible, it is possible.

Aluminum and copper have no effect on the magnetic shield, and iron and silicon steel are insufficient because of low magnetic permeability. High-permeability amorphous metal can provide high-efficiency magnetic shielding. Since the amorphous metal has a narrow width if it is in the form of a ribbon, the workability in the case of compounding becomes complicated, and therefore a laminate of amorphous alloy pieces is preferable.

If the thickness of the amorphous alloy piece is less than 5 μm, it is difficult to produce the amorphous alloy piece, and if the thickness exceeds 100 μm, it becomes difficult to form an amorphous alloy piece.
m. A particularly preferred thickness is 20 to 60 μm. If the aspect ratio of the amorphous alloy piece is less than 10, the magnetic permeability of the amorphous alloy piece decreases, and the magnetic shielding properties of the amorphous alloy piece change, so that lamination becomes difficult and the magnetic shielding property deteriorates. Become like On the other hand, if the aspect ratio exceeds 15,000, handling of the amorphous alloy piece becomes troublesome, and the productivity decreases. A particularly preferred aspect ratio range is 50
~ 10,000.

The above-mentioned flake-shaped soft magnetic amorphous alloy piece is produced as follows. The cavitation method disclosed by the present applicant in Japanese Patent Application Laid-Open No. 58-6907 (a molten metal is applied to the surface of a roll rotating at high speed, which has a surface layer with low leakage to the molten gold). The molten metal is divided into fine molten metal droplets, and subsequently, the molten metal droplets collide with a rotating metal body rotating at a high speed to rapidly cool and solidify, thereby obtaining Co _68.8 Fe _4.2 Si ₁₆ B _An amorphous alloy flake of ₁₁ (the number attached to the element symbol represents the atomic% of the element component; the same applies hereinafter). The magnetostriction of this amorphous alloy is zero, the saturation magnetic flux density is 7000 G, the magnetic permeability is 10,000, and the crystallization temperature is 512.
° C.

(Example 1) A rectangular shape was formed with an L-shaped angle 3 as shown in FIG. 1, and a 2.3 mm-thick iron plate 2 was bent thereon, and a box-shaped shape was produced by spot welding. As shown in FIGS. 1 and 2, an amorphous alloy piece laminated sheet 1 as described above is further placed on the iron plate 2.
With an adhesive to adhere to the shape, 600mm
A panel with a width of 1,200 mm and a length of 50 mm was used. In the center in the height direction of this panel, holes 5 for bolt tightening are formed at a pitch of 100 mm. 4.8m width x 6m using this panel
A shield room measuring 2.4 x 2.4m in length was created. The panels were tightened with bolts and nuts 6 in holes 5 previously drilled, and then, as shown in FIG. 3, welding 8 was performed so that the iron plates 2 were connected. The corner is the fourth
As shown in the figure, after fixing with an auxiliary angle 10 with a bolt 11, the angle 10 and an iron plate were welded. As a result, this shield room can reduce the static magnetic field 5G to 1G or less, and obtain an attenuation rate of more than 60dB from 500KHz to 1GHz, and can be used from the magnetic shield of the static magnetic field to the electromagnetic shield in the high frequency range Thus, the construction period was shortened to two-thirds compared to the conventional construction method using a lightweight steel frame, and the cost was reduced.

(Example 2) The amorphous alloy piece laminated sheet 1 in Example 1 was a sheet in which the weight of the amorphous alloy piece was 1 kg / m ² and an aluminum film of 25 µm was used instead of the polyester film.

As in the case of the first embodiment, the panel is formed by using an L-shaped angle 3 to form a frame, on which a 0.5 mm-thick silicon steel plate 2 is fixed in a box shape. The piece laminated sheet 1 was fixed with adhesive. The shape was exactly the same as in Example 1. A heat resistant plywood 9 is further placed on the upper surface of this panel.
It was attached as shown in the figure.

The shield room is 4.8m wide x 6m long x 2.4m high,
The joints between the panels were capped with aluminum auxiliary material 7 so as to cover both angles 3 and then tightened with bolts 6. The corner is an L-shaped auxiliary angle 10 as shown in Fig. 4.
Then, after capping with aluminum auxiliary material 7 as necessary, bolts 11 were tightened. This shield room,
50Hz 500mG magnetic field can be 50mG, M Hz ~ 10M
The attenuation rate of more than 80dB at Hz was obtained. Also, after the joint of the heat-resistant plywood 9 was completed after the assembly, finishing was possible only by painting, and the construction period could be reduced to half of the conventional one.

Example 3 As shown in FIG. 6, a frame was formed with a 50 mm square aluminum pipe 4, a box shape was formed with a 2 mm thick aluminum plate 2, and the amorphous shape shown in Example 1 was further formed thereon. Sheet 3 in which the weight of the amorphous alloy flakes is 1 kg / m ²
Was attached to form a panel having a width of 600 mm × 2,400 mm and a length of 50 mm.

Using this panel, a shield room of 4.2m width x 6m length x 2.4m height was manufactured. As shown in FIG. 7, the connection part was tightened with bolts 6 using an aluminum auxiliary material 7. The corners were fixed using L-shaped angles as shown in FIG.

This shield room can reduce the fluctuating magnetic field 100 mG to 20 mG or less, and 100 dB at 1 MHz to 100 MHz.
The above attenuation rate was able to be obtained. The construction period was also greatly shortened, and could be reduced to two thirds.

In addition to the above, the shield room is manufactured in a case where the magnetic field in the room is not desired to be leaked to the outside. In order to manufacture the shielded room, it is necessary to dispose the amorphous alloy laminated sheet on the outside. Therefore, it is necessary to construct a corner as shown in Figs. When an auxiliary material is used, a construction method as shown in FIGS. 11 and 12 may be adopted.

(Effect) The panel of the present invention is a shielding material having excellent electromagnetic shielding properties and excellent shielding properties of magnetic shielding properties.

Next, when constructing the electromagnetic and magnetic shield room,
Unlike the conventional construction method of framing the skeleton with lightweight steel frames or wood, a connection can be easily made by drilling holes in the bent parts of the panels in advance and tightening them with bolts and nuts Therefore, the construction period is greatly reduced.

Also, if the frequency is particularly high with an electromagnetic shield, a small space becomes a problem.Welding the bent parts of the panels or placing a U-shaped auxiliary material in the bolted part will make the joint part. Leakage can be prevented, and electrical conductivity can be obtained.

Further, if a concrete panel or a heat-resistant plywood for finishing is previously attached to the front of the panel, it can be finished only by jointing and painting between the panels after assembly, so that the construction period is greatly shortened.

[Brief description of the drawings]

1 is a perspective view of a panel according to an embodiment of the present invention, FIG. 2 is a cross-sectional view thereof, FIG. 3 is a cross-sectional view of a butt portion, FIG. 4 is a cross-sectional view of an example of a corner portion, and FIG. 6 is a cross-sectional view of an example using a pipe, FIG. 7 is a cross-sectional view of a butt portion using an auxiliary material and a pipe, and FIG. 8 is a pipe using a pipe. 9 and 10 are cross-sectional views showing examples using an amorphous alloy as an outer wall, and FIGS. 11 and 12 are cross-sectional views showing examples using an auxiliary material and an amorphous alloy as an outer wall. It is sectional drawing. In the figure, 1 ... Amorphous alloy laminated sheet 2 ... Iron, silicon steel, aluminum, copper 3 ... L-shaped angle 4 ... Pipe 5 ... Hole 6 ... Bolt / nut 7 ... Auxiliary material 8 ... ... welding 9 ... heat-resistant plywood, concrete panel 10 ... auxiliary L-angle

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Yukio Toda 810 Kumagaya, Kumagaya-shi, Saitama Prefecture RIKEN Kumagaya Office (72) Inventor Kazuhiro Nishimura 810 Kumagaya, Kumagaya-shi Saitama Prefecture Inside Riken Kumagaya Office (56) References JP-A-62-146337 (JP, A)

Claims (1)

(57) [Claims] 1. A square frame composed of an L-shaped angle or a pipe, an iron plate, a silicon steel plate, an aluminum plate, or a copper plate disposed on the frame, the ends of which are arranged along the L-shaped angle and the pipe. It has a box shape bent at 90 °, and further has a soft magnetic amorphous alloy portion disposed thereon, the amorphous alloy portion has a thickness of 5 to 100 μm, and an aspect ratio of 10 to 15,000.
Flake-shaped soft magnetic amorphous alloy pieces are laminated on each other.
An electromagnetic shield panel connected and fixed with bolts and nuts.