JPH0440319Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field This invention is suitable for housing electric discharge machining equipment, high frequency treatment equipment, communication equipment, etc. that generate noise that causes electromagnetic interference in other equipment such as televisions, and other equipment. The present invention relates to an electromagnetic shielding room used for medical electroencephalography, electrocardiography, electromyography, electronic component testing, electronic environment testing, etc., which are susceptible to electromagnetic interference due to equipment noise.

BACKGROUND OF THE INVENTION An electromagnetic shielding room is normally used in which the ceiling, floor, and walls facing indoors and facing outdoors are covered with electromagnetic shielding conductive sheets. Such an electromagnetic shield room is provided with an opening for installing a ventilation fan or connecting an air conditioning duct.

Problems to be Solved by the Invention In the conventional electromagnetic shielding chamber described above, there was a problem in that noise entered or leaked through such openings, causing electromagnetic interference.

The purpose of this invention is to provide an electromagnetic shielding room that solves the above problems.

Means for Solving the Problems This invention is based on an opening formed in a peripheral wall or ceiling in which at least one of the surfaces facing indoors and facing outdoors is covered with a conductive sheet for electromagnetic shielding. In an electromagnetic shielding chamber covered with two layers of porous sheet material for electromagnetic shielding, inside and outside, the peripheries of both porous sheet materials for electromagnetic shielding are electrically connected to the conductive sheet for electromagnetic shielding, respectively. Among the double porous sheet materials for electromagnetic shielding, one porous sheet material is a metal honeycomb structure, and the other porous sheet material is wire mesh, punched metal, or expanded metal. It is characterized by this.

Function This device has the above-mentioned configuration, so
Excellent shielding effect against noise in all frequency bands. In other words, the shielding effect of wire mesh is the fourth
As shown by curve X in the figure, it is excellent against low frequency noise, but inferior against high frequency noise. In addition, the shielding effect of punched metal and expanded metal is better than wire mesh against low-frequency noise, but inferior to high-frequency noise, as shown by curve Y in Figure 4. is superior to wire mesh. On the contrary, the shielding effect of the metal honeycomb structure is excellent against high-frequency noise, but inferior against low-frequency noise, as shown by curve Z in FIG. Therefore, when used in the above combination, an excellent shielding effect is achieved against noise in all frequency bands.

Embodiments Hereinafter, embodiments of this invention will be described with reference to the drawings.

FIG. 1 shows the entire electromagnetic shielding chamber according to this invention.

The electromagnetic shielding room 1 is a prefabricated type, and its ceiling 1a, floor 1b, and peripheral wall 1c are each made of a core material 4 made of a heat insulating material, and an aluminum (including aluminum alloy; the same shall apply hereinafter) covering both sides of the core material 4. Material 5
It is constructed by connecting a plurality of panels 3 having a sanderch structure. ceiling 1
a. For joints between adjacent panels on the floor 1b and peripheral wall 1c, joints between adjacent ceiling panels 3 and peripheral wall panels 3, and joints between adjacent ceiling panels 3 and peripheral wall panels 3, appropriate devices are used. By energizing the skin materials 5, electromagnetic waves are shielded. The skin material 5 of each panel 3 serves as a conductive sheet for shielding electromagnetic waves on the ceiling 1a, floor 1b, peripheral wall 1c, and partition wall 2. Further, a reinforcing water-resistant plywood board (not shown) is laid on the floor 1b, and its surface is further covered with a vinyl chloride floor finishing material (not shown).

A fluorescent lamp device 8 and a smoke detector 9 are provided on the ceiling 1a of the electromagnetic shielding room 1, and are covered with electromagnetic shielding covers 10 and 11 made of copper mesh, respectively.

As shown in FIGS. 2 and 3, two openings 12 and 13 are formed in the peripheral wall 1c, one opening 12 is provided with a ventilation fan 14, and the other opening 13 is provided with an air conditioning duct. 15 are connected. A pair of clamping walls 16a, 1 are provided around the peripheries of both openings 12, 13, respectively, each having a U-shaped cross section and clamping the opening edges of the panel 3 constituting the peripheral wall 1c.
Opening frame 1 made of aluminum extrusion with 7a
6 and 17 are attached. The ventilation fan 14 is attached to a mounting frame 18 fixed to the surface of the peripheral wall 1c facing outdoors so as to surround the opening 12. The mounting frame 18 is box-shaped and is attached to the surrounding wall 1 with its opening facing indoors and the tip of the surrounding wall being in contact with the surrounding wall 1c.
It is fixed at c. The ventilation fan 14 is attached to the mounting frame 18 so as to pass through the bottom wall of the mounting frame 18. The air conditioning duct 15 is connected to the opening 13 via a bellows type joint 20. Flanges 21 are provided at both ends of the joint 20, and the flange 21 at one end is screwed to the peripheral wall 1c, and the flange 21 at the other end is screwed to the flange 15a at the tip of the duct 15.

Both openings 12 and 13 are made of porous sheet-like materials 22, 23, 2 for electromagnetic shielding, which have two layers inside and outside, respectively.
It is covered by 4,25. The porous sheet-like material 22 for electromagnetic shielding on the indoor side of the opening 12 on the side where the ventilation fan 14 is provided is made of an aluminum honeycomb structure, and its peripheral edge is secured by a mounting frame 26 made of an extruded aluminum material. is detachably attached to the peripheral wall 1c so as to be electrically connected to the outdoor skin material 5 of the panel 3 constituting the peripheral wall 1c. The mounting frame 26 has an outdoor side bent portion 26b provided at the outer peripheral edge of a plate-shaped portion 26a that sandwiches the peripheral edge of the porous sheet-like material 22 with the indoor side sandwiching wall 16a of the opening frame 16. A space is provided between the bent portion 26b and the peripheral edge of the porous sheet material 22, and a conductive gasket 27 is provided in the half of this space on the bent portion 26b side.
is located. The conductive gasket 27 is made of conductive rubber or has an elastic gasket body whose surface is covered with a sheet-like conductive member. As the sheet-like conductive member, a wire mesh-like member, a sheet-like member made by weaving metal fibers, a metal foil, etc. are used. Further, a copper net 28 is arranged on the outdoor side surface of the electromagnetic shielding porous sheet material 22 so as to cover it. The outer peripheral edge of the copper mesh 28 is bent toward the outdoors and outward from the opening frame 16.
6 The part bent outward is the conductive gasket 27
and the plate-like portion 26a of the mounting frame 26. The porous sheet material 22 is removably attached to the peripheral wall 1c by screwing screws 29 passing through the mounting frame 26, the copper mesh 28, and the clamping wall 16a into the peripheral wall 1c. opening 1
The outdoor porous sheet material 23 in 2 is:
It is made of 16 mesh copper mesh, and its peripheral edge is electrically connected to the outdoor skin material 5 of the panel 3 constituting the peripheral wall 1c by a frame-shaped mounting member 30 made of extruded aluminum. It is attached removably. The mounting member 30 includes a plate-shaped portion 30a that is brought into close contact with the outdoor sandwiching wall 16a of the opening frame 16, and the inner peripheral edge thereof is bent toward the indoor side so that it is brought into close contact with the inner peripheral surface of the opening frame 16. made to do,
Moreover, its tip is bent inward of the opening frame 16. The peripheral edge of the porous sheet material 23 is
It is sandwiched between the plate-shaped portion 30a of the mounting member 30 and the outdoor-side sandwiching wall 16a of the opening frame 16. Then, by screwing the screw 31 passing through the mounting member 30, the porous sheet material 23, and the sandwiching wall 16a into the peripheral wall 1c, the porous sheet material 23
is detachably attached to the peripheral wall 1.

The porous sheet-like material 24 for electromagnetic shielding on the indoor side of the opening 13 to which the air conditioning duct 15 is connected is made of an aluminum honeycomb structure, and covers the periphery of the opening 13 on the indoor-facing surface of the peripheral wall 1c. It is attached to a frame 32 made of extruded aluminum profile that is attached to the surface. The frame 32 has an indoor bent portion 32b provided at the outer peripheral edge of a plate-shaped portion 32a whose inner peripheral edge abuts the peripheral edge of the indoor-facing surface of the porous sheet-like material 24. A space exists between the bent portion 32b and the peripheral edge of the porous sheet material 24, and a conductive gasket 33 is provided in the inward half of the frame 32 within this space.
is located. The conductive gasket 33 has the same structure as the conductive gasket 27 described above. The frame 32 is removably attached by screwing into the peripheral wall 1c a screw 34 passing through the plate-shaped portion 32a and the clamping wall 17a. The porous sheet-like material 24 is disposed on the outdoor side of the plate-like portion 32a of the frame 32 so that its peripheral edge is in contact with the plate-like portion 32a. A copper mesh 34 is arranged on the outdoor side surface of the porous sheet material 24 so as to cover it. The outer peripheral edge of the copper mesh 35 is bent toward the indoor side and outward from the opening frame 17.
7. The part bent outward is the conductive gasket 33
and the plate-shaped portion 32a of the frame 32. The porous sheet material 24 is attached to the frame 32 through the copper net 35, and is electrically connected to the skin material 5 of the panel 3 via the frame 32, the copper net 35, the conductive gasket 33, and the opening frame 17. It is connected. The porous sheet material 25 for electromagnetic shielding on the outdoor side of the opening 13 is made of 16 mesh copper mesh, and its peripheral edge is connected to the flange 21 of the joint 20 and the sandwiching wall 17a on the outdoor side of the opening frame 17. panel 3 through the opening frame 17.
It is electrically connected to the skin material 5 of.

Effects of the invention According to the electromagnetic shielding chamber of this invention, since the porous sheet-like material for electromagnetic shielding, which is double layered inside and outside that covers the opening, is a combination of the above-mentioned specific materials, it is able to withstand noise in all frequency bands. Since it exhibits an excellent shielding effect, it is possible to prevent leakage of electromagnetic waves through the opening, thereby preventing electromagnetic interference from occurring.

[Brief explanation of drawings]

Fig. 1 is an exploded perspective view with a part cut away of the electromagnetic shielding room according to this invention, Fig. 2 is an enlarged vertical sectional view of the part where the ventilation fan is installed, Fig. 3 is an enlarged horizontal sectional view of the duct connection port, FIG. 4 is a graph showing the relationship between noise frequency and shielding effect in various porous sheet materials. 1... Electromagnetic shield room, 1c... Peripheral wall, 5...
...Skin material (conductive sheet for electromagnetic shielding), 12,
13... Opening, 22, 23, 24, 25... Porous sheet material for electromagnetic shielding.

Claims (1)

[Scope of utility model registration request] A porous sheet for electromagnetic shielding, in which at least one of the surfaces facing indoors and facing outdoors is covered with a conductive sheet for shielding electromagnetic waves, and an opening formed in a peripheral wall or ceiling is double-layered inside and outside. In an electromagnetic shielding chamber covered with a porous sheet-like material for electromagnetic shielding, the peripheral edges of both porous sheet-like materials for electromagnetic shielding are electrically connected to the conductive sheet for electromagnetic shielding, respectively. An electromagnetic shielding chamber characterized in that one of the porous sheet-like materials is a metal honeycomb structure, and the other porous sheet-like material is a wire mesh, punched metal, or expanded metal.