JPH0234880Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an electromagnetic shielding sheet that prevents electromagnetic interference caused by electromagnetic energy radiated from an electromagnetic wave generation source to electrical equipment, signal lines, etc.

[Prior Art] If a large amount of electromagnetic energy enters from the outside through gaps such as opening/closing parts or connecting parts of a case in which an electrical device is housed, the electrical device may malfunction or generate noise. Alternatively, electromagnetic energy emitted from an electrical device may affect external equipment.

To prevent such electromagnetic interference, electromagnetic shielding sheets are commonly used. As shown in FIG. 4, this type of electromagnetic shielding sheet includes, for example, an electromagnetic shielding sheet 25 that has metal wires 27 embedded at regular intervals in the vertical direction with respect to the surface of a sheet 26 made of an elastomer such as silicone rubber. There is.

When this is placed in the opening/closing part or the gap between the joints of a case in which an electrical device is housed, the metal wire 27 embedded in the sheet 26 reflects, absorbs and shields electromagnetic waves, and the sheet 26 made of elastomer covers the case. Keep it airtight and watertight.

[Problems that the invention aims to solve] By the way, conventional electromagnetic shielding sheets are made by arranging multiple metal wires at regular intervals between each sheet of multiple elastomer sheets, and applying heat treatment while pressing the sheets. It is manufactured by fusing and integrating each sheet to create an elastomer block containing metal wires regularly arranged at lattice points, and then cutting this elastomer block into thin pieces perpendicular to the direction in which the metal wires are arranged.

Therefore, conventional electromagnetic shielding sheets require a lot of time and effort to produce, resulting in poor productivity.

In addition, when using the electromagnetic shielding sheet produced in this way by inserting it into the opening of a metal case, each metal wire conducts through the case, so the opening of the case can be shielded, but it is difficult to cover cables, etc. However, if you try to shield the metal wires in the elastomer sheet, there is a problem that the metal wires in the elastomer sheet cannot be electrically connected to each other, so it cannot be shielded.

Furthermore, the cut ends of the metal wires are exposed on the surface of the elastomer sheet, which may cause injury when handled with fingers.

Therefore, the present invention has been devised for the purpose of providing an electromagnetic shielding sheet that is easy to manufacture, can cover and shield cables, etc., and is safe to handle.

[Means for Solving the Problems] That is, the structure of the present invention, which was made to solve the above problems, consists of an elastomer sheet and a conductive material sewn continuously so as to be exposed on the front and back surfaces of the elastomer sheet. The subject matter is an electromagnetic shielding sheet characterized by comprising fibers and.

The material of the elastomer sheet may be any material that is a filler and has elasticity, such as neoprene rubber or silicone rubber.

[Function] By firmly filling the opening of the case with the electromagnetic shielding sheet configured as described above,
The inside of the case is sealed against water and air, and electromagnetic energy radiated outside and inside is
Even if you try to pass through this electromagnetic shield sheet, it will be reflected and absorbed. Furthermore, when wrapped around a cable, electromagnetic energy radiated from inside or outside the cable is reflected and absorbed.

[Example] Next, an example of the electromagnetic shielding sheet of the present invention will be described. FIG. 1 is a partially enlarged view showing a first embodiment of the electromagnetic shielding sheet of the present invention.

As shown in the figure, the electromagnetic shielding sheet 1 of this embodiment is made by continuously sewing conductive fibers 4 onto a rubber sheet 3 (corresponding to the elastomer sheet) formed into a tape using a sewing machine or the like. There is. A mesh cloth 2 is fitted inside the rubber sheet 3. This cloth may be made of synthetic fibers, but in order to further enhance the shielding effect, a cloth made of synthetic fibers plated with metal or a cloth made of metal may also be used. The electromagnetic shielding sheet 1 is reinforced by this cloth 2.

Furthermore, the conductive fiber 4 is made by winding a thin copper wire 4b around a synthetic fiber 4a.

Such an electromagnetic shielding sheet 1 may be used by winding it with a tape winding tool and cutting it to the required length with scissors.

For example, when shielding the gap between a rectangular parallelepiped case containing electronic components and its lid, cut the electromagnetic shielding sheet 1 to a length along the joint surface between the case and the lid in advance, and then spread it tightly when putting the lid on. Just close it. In this way, the case is made watertight and airtight by the rubber sheet 3, and is also shielded from electromagnetic waves radiated from the outside by the conductive fibers 4. Further, since the case and the case lid are in line contact with the conductive fibers 4, firm conduction can be established, and since no potential difference is generated, corrosion of the connection portion can be prevented.

Another way to use it is to wrap it continuously around a long cable such as a signal line or power line to shield the cable. In other words, in this case, in order to prevent the electromagnetic shielding sheet 1 from coming off during the winding process, the beginning part of the winding should be firmly fixed with adhesive tape, and when the winding is finished, it should be fixed firmly in place, and then it can be wrapped around the cable. The electromagnetic wave shielding sheet 1 can shield electromagnetic waves radiated from inside and outside the cable. In this case, by winding the electromagnetic shielding sheet 1 in two or three layers, the conductive fibers 4 can be made denser and the shielding effect can be enhanced.

In this way, the electromagnetic shielding sheet 1 of this embodiment
According to , it's made into a tape, so you can easily cut it with scissors and use it for various things such as cases and cables. Since the mesh cloth 2 is inserted between the rubber sheets 3 of the electromagnetic shielding sheet 1, it is possible to increase the strength and durability. Furthermore, since the conductive fibers 4 are simply sewn onto the rubber sheet 3, the surface is smooth and can be handled safely without causing injury.

The conductive fiber 4 in this embodiment is made by wrapping a thin copper wire 4b around a synthetic fiber 4a, but the conductive fiber may be any material with high conductivity and may also be realized by carbon fiber, metal fiber, etc. can.

Now, in the first embodiment, we briefly explained how to shield cases and cables using the versatile electromagnetic shielding sheet 1 as an example. It is more convenient to use an electromagnetic shielding sheet because it saves the trouble of pasting the sheets together. Therefore, the electromagnetic shielding sheet of the present invention made in this manner will be described in detail as a second embodiment.

FIG. 2 is a perspective view showing a case that houses the electromagnetic shielding sheet of this embodiment and the electronic components to which it is attached.

Case 1 is a rectangular parallelepiped made of metal as shown in the figure.
The upper part of 1 is an opening for storing electronic components. The case lid 12 that closes this is also made of metal, and between this and the case 11 there is a hinge part 1 that allows the case lid 12 to rotate and open and close.
3 is installed. In addition, the case lid body 12
An electromagnetic wave shielding sheet 15 of this embodiment is laid on the edge 14 where the case 11 and the case 11 meet.

The electromagnetic wave shielding sheet 15 of this embodiment has a first
As in the example, five conductive fibers 16 made by wrapping thin copper wire around the fibers are sewn to the perforations on a square-shaped rubber sheet formed corresponding to the edge 14 of the case 11. In addition, a mesh cloth is inserted between the rubber sheets as in the first embodiment. Also, case lid 1
When the case 2 is closed, the case 11 and the case lid 12 are tightened together with the electromagnetic shielding sheet 15 in between, so that the lid tightening part 17 is attached to the case 11 and the case lid 12 so that the inside of the case 11 can be sealed. It is provided. Furthermore, on the side of case 11,
A waterproof connector 18 is attached to take out signal lines of electronic components (not shown) housed inside the case 11 to the outside.

In this way, electronic components are stored in the case 11,
When the electromagnetic shielding sheet 15 is sandwiched between the case 11 and the case lid 12 and the lid tightening part 17 is tightened, the electronic components are completely sealed inside the case 11 and are shielded from outside moisture and air. At the same time, it is also shielded from electromagnetic waves generated and radiated outside the case 11.

As mentioned above, according to the electromagnetic wave shielding sheet 15 of this embodiment, since it is formed in a square shape, the case 11
It can be easily installed.

Next, if you want to use it exclusively for wrapping cables, it would be more convenient to have an adhesive applied to the back of the tape of the electromagnetic shielding sheet, or something that prevents the conductive fibers from breaking even if you pull the tape with some force. The electromagnetic shielding sheet constructed in this way will be described in detail as a third embodiment.

Figure 3 shows the electromagnetic shielding sheet 2 of this example.
2 and a multicore cable 21 around which it is wound.

As shown in the figure, one turn of an electromagnetic shielding sheet 22 formed in the form of a tape is continuously wound around a multicore cable 21 including eight signal lines. In this electromagnetic shielding sheet 22, the rubber sheet 2
A conductive fiber 24 is sewn in a linear, stretchable manner in the longitudinal direction of the fiber 3, and an adhesive is applied to the back surface of the conductive fiber 24.

Electromagnetic shielding sheet 22 on multicore cable 21
When wrapping, stretch and stretch it to prevent it from getting wrinkled and sticking. Then, the conductive fibers 24 of the electromagnetic shielding sheet 22 wrapped around
Accordingly, the signal line inside the multi-core cable 21 can be prevented from being disturbed by external electromagnetic waves, and the surface of the multi-core cable 21 can be protected from scratches and corrosion.
Moreover, the strength can be maintained against bending or breaking of the multicore cable 21.

According to the electromagnetic wave shielding sheet 22 of this embodiment, adhesive is applied to the back side of the tape, so it is easy to paste, and since it is sewn in a linearly elastic manner, it does not have to be pulled with some force. It will never break.

In the embodiment of the electromagnetic shielding sheet of the present invention described above, the conductive fibers are simply sewn in a straight line at equal intervals, but the conductive fibers only need to be sewn in a straight line. It is not necessary. In other words, for example, by repeatedly sewing conductive fibers back and forth in a certain sewing area, or by making the sewing pitch finer, the shielding characteristics against electromagnetic waves can be varied depending on the position of the electromagnetic shielding sheet. In addition, by sewing the shielding properties of the electromagnetic shielding sheet itself into the shape of letters or marks that represent the company name or product name,
Usability can be improved and advertising effects can also be increased. Furthermore, when using it for indoor cables, etc., the electromagnetic shielding sheet is exposed, so
For example, by sewing conductive fibers in a floral pattern, it can be made to match the interior decoration sense. Further, in this case, the effect can be further enhanced by making the color of the rubber sheet and the conductive fibers a bright combination of orange and yellow-green, for example.

[Effects of the invention] As detailed above, the electromagnetic shielding sheet of the invention can be easily manufactured by simply sewing conductive fibers onto an elastomer sheet using a sewing machine, and the sewing pattern or sewing pitch can be partially different. This allows the shielding characteristics to be changed.

In addition, conductive fibers are continuously sewn onto the elastomer sheet to ensure tightness and conductivity, so even if it is covered with a cable, it can be shielded from the cable.

Furthermore, the surface of the sheet is smooth and the ends of the metal wires do not show on the surface, making it safe to handle.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an electromagnetic shielding sheet according to a first embodiment of the present invention, Fig. 2 is a perspective view showing a second embodiment of an electromagnetic shielding sheet according to the present invention and a case in which it is attached, and Fig. 3 4 is a perspective view showing a third embodiment of the electromagnetic shielding sheet of the present invention and a multicore cable around which it is wound;
The figure is a perspective view showing a conventional electromagnetic shielding sheet. 1, 15, 22...electromagnetic shield sheet,
4, 16, 24... Conductive fiber, 3, 23... Rubber sheet, 11... Case, 12... Case lid,
21...Multi-core cable.

Claims (1)

[Scope of Claim for Utility Model Registration] An electromagnetic shielding sheet comprising: an elastomer sheet; and conductive fibers sewn continuously so as to be exposed on the front and back surfaces of the elastomer sheet.