JPH0230876Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention relates to a radio wave absorber in an anechoic chamber, and more specifically uses foamed polyurethane or foamed polystyrene as a base material, and carbon black, etc. as a dielectric loss material. This invention relates to a radio wave absorber that reinforces a wave-shaped radio wave absorber containing.

[Prior art]

In recent years, with the development of computers, OA equipment (office automation equipment) such as world processors, and other electrical products that use IC circuits (integrated circuits), electromagnetic interference oscillated by these products has increased. It's becoming a problem.

In other words, OA equipment and electrical products that use IC circuits oscillate electromagnetic waves at a certain frequency, and this electromagnetic wave can cause errors when OA equipment and electrical products are used in close proximity to each other. activating the device or watching TV near it,
When listening to the radio, the current situation is that radio waves such as TV images and radio sounds are greatly affected.

Therefore, in recent years, in order to reduce electromagnetic interference, inspections have been made to see if the frequency of electromagnetic waves emitted from office automation equipment and electrical products using IC circuits are within certain standards. Only what is inside is allowed to enter the market distribution process.

By the way, in the past, to measure the amount of radio waves oscillated by office automation equipment and electrical products that use IC circuits, an anechoic chamber in which a material that absorbs radio waves in the low frequency band is placed indoors has been used. There is.
In this anechoic chamber, in order to create a large free space in the room, it is necessary to use radio wave absorbing materials with as good radio wave absorption performance as possible. A radio wave absorbing material is used that absorbs the radio wave with a magnetic loss material.

Conventional radio wave absorbing materials 1a and 1b include, for example, those provided with square pyramid-shaped protrusions 2 on the surface as shown in FIG. 4, and those provided with wave-shaped protrusions 3 on the surface as shown in FIG. things are known.

The constituent materials of these radio wave absorbers 1a and 1b are foamed polyurethane or foamed polystyrene as a base material, and contain carbon black or the like as a dielectric loss material.
It is used by attaching the back surfaces of a and 1b to the inner wall surface of the anechoic chamber via an adhesive or the like. However, such conventional radio wave absorbing materials1
When a and 1b are used on the wall of a radio wave anechoic chamber for a long period of time, a so-called "sag phenomenon" occurs in which the protrusions 2 and 3 tilt downward due to the properties of the constituent materials of the radio wave absorbers 1a and 1b. When this sagging phenomenon occurs,
There was a problem in that the electromagnetic wave absorption performance deteriorated, making it impossible to accurately measure the amount of electromagnetic waves generated.

In addition, radio wave absorbing materials 1a and 1b are placed on the wall of the anechoic chamber.
If the radio wave absorbers 1a and 1b are installed, there is a risk that the tips of the radio wave absorbers 1a and 1b may come into contact with people or objects walking or working indoors and be damaged, which may cause radio wave problems. It was hot. Furthermore, even if such radio wave absorbing materials 1a and 1b are laid on a part of the floor of an anechoic chamber, the protrusions 2 and 3 are not strong enough, so they can only be laid on the floor on which people walk. There was a problem.

[Purpose of invention]

This idea was devised by focusing on such conventional problems, and its purpose is that even if the radio wave absorbing material is used for a long period of time on the side walls of the anechoic chamber, the tip of the radio wave absorbing material It effectively prevents downward tilting, allows accurate measurement of the amount of electromagnetic waves generated in the anechoic chamber, and can also be used to protect the radio wave absorbing material attached to the side wall. To provide a radio wave absorber that is strong enough to be walked on even when laid on the floor.

[Structure of the idea]

In order to achieve the above object, this invention consists of a radio wave absorbing material having an engaging part and a radio wave transparent body having an engaging part that removably fits into the engaging part of the radio wave absorbing material. By fitting a radio wave transparent material into the recess of the radio wave absorbing material, it is possible to effectively prevent the tip of the radio wave absorbing material from tilting downward, and also to protect the radio wave absorbing material attached to the side wall. The gist of the invention is that the protrusion is made strong enough to be used for walking parts.

[Example of idea]

Embodiments of this invention will be described below based on the accompanying drawings.

Figure 1 shows a radio wave absorber 11 implementing this idea.
A radio wave absorbing material 12 and a radio wave transparent material 13 constituting the
The radio wave absorbing material 12 has an inverted pyramid-shaped recess 12a (engaging portion) formed on its surface,
Its constituent material is a base material of foamed polyurethane or foamed polystyrene containing a dielectric loss material, and carbon black or the like as the dielectric loss material.

Furthermore, the radio transparent material 13 has a quadrangular pyramid-shaped projection 13.
a (engaging portion) on the surface, and this protrusion 13a is formed to fit into an inverted pyramid-shaped recess 12a (engaging portion) of the radio wave absorbing material 12.

The radio-transparent material 13 is made of a material that is radio-equivalent to air, such as foamed polyurethane or foamed polystyrene.

Radio transparent material 1 provided with such a protrusion 13a
3 is an inverted pyramid-shaped recess 12a of the radio wave absorbing material 12.
When configured by fitting into the (engaging portion), the surface becomes flat plate-like, and the inside has an inverted pyramid-shaped recess 12a.
The square pyramid-shaped protrusions 13a are completely fitted into the grooves, and the strength of the radio wave absorbing material 12 can be increased.

Note that the shapes of the radio wave absorbing material 12 and the radio wave transparent material 13 may be reversed, and in this case, the constituent materials are also reversed.

As described above, by configuring the radio wave absorber 11, it is possible to reinforce the downward tilting of the tip of the radio wave absorber 11, making it possible to construct a radio wave absorber 11 with high strength. It can also be used to protect the attached radio wave absorbing material, and even if it is laid on the floor, it can be walked on easily.

Further, FIGS. 2 and 3 show another embodiment of this invention, in which a wave-shaped protrusion 3 is provided on the surface of a concave portion 15 of a radio wave absorbing material 11a provided with a quadrangular pyramid-shaped protrusion 14 on the surface. Radio transparent material 1 made of foamed polyurethane or foamed polystyrene provided in
6 are fitted in parallel to each other.

Further, the radio transparent material 16 of the above embodiment may be constructed integrally, but the plate material 16 with a thickness of 50 mm or more
A and the triangular prism-shaped member 16b may be formed separately and then integrally joined with adhesive.

[Effect of idea]

This invention consists of a radio wave absorbing material with an engaging part as described above and a radio transparent body having an engaging part that removably fits into the engaging part of this radio wave absorbing material. It is possible to construct a strong radio wave absorber without changing the radio wave absorption performance.As a result, it is possible to always measure the amount of electromagnetic waves generated with high precision in the anechoic chamber. It can also be used to protect materials, and even when laid on the floor, it can be used for walking.

[Brief explanation of the drawing]

Fig. 1 is an overall perspective view of a radio wave absorber and a radio transparent material implementing this invention, Fig. 2 is a perspective view showing another embodiment of this invention, and Fig. 3 is a diagram showing the fitted structure of Fig. 2. 4 and 5 are perspective views of a conventional radio wave absorbing material. 11...Radio wave absorber, 12...Radio wave absorber, 1
2a... recessed part (engaging part), 13... radio transparent material,
13a...Protrusion (engaging part).

Claims (1)

[Scope of utility model registration request] A radio wave absorber comprising: a radio wave absorber having an engaging part; and a radio transparent body having an engaging part that removably fits into the engaging part of the radio wave absorber.