JPH1041675A - Sound and radio wave absorber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the test of both sound wave and electromagnetic wave in one room and semi-incombustible handling by inserting sound absorber on the surfaces of pyramid, wedge or polygonal sheet-made wave absorbers or between them and making each absorber of an incombustible material. SOLUTION: The radio wave absorber 1 is a pyramid absorber having quadrangular pyramid absorber members which are made of an incombustible foam styrene, etc., hardly producing a harmful gas and pasted in arrays on the ceiling and walls of a test room. Sound absorbers 2 composed of inverse quadrangular pyramid longitudinal and wavy inorg. short fibers are buried in and adhered to recesses between the radio wave absorbers so as to be flush with the entire surface. The fibers orient in the depth direction of the absorber or at random. Instead of the quadrangular pyramid sound absorber, an absorber composed of longitudinal and wavy inorg. short fibers having truncated trapezoidal shape by truncating quadrangular pyramid top.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorber for absorbing both sound waves and electromagnetic waves.

[0002]

2. Description of the Related Art
Manufacturers of various electrical products have installed an anechoic chamber with a radio wave absorber attached to the ceiling or wall for product testing,
Acoustic test room 2 with sound absorber attached to ceiling and wall
A room was prepared for both tests. However, preparing two rooms, an anechoic chamber and an acoustic test chamber, requires an installation space for the two chambers and a huge amount of construction funds. In addition, since urethane is used as the absorber, there are problems such as burning and emission of toxic gas during burning.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and enables a test for both a sound wave and an electromagnetic wave to be performed in one room, and provides a sound wave and radio wave absorber which can be a quasi-noncombustible absorber. The purpose is to provide.

[0004]

SUMMARY OF THE INVENTION According to the present invention, by using an absorber that absorbs both sound waves and electromagnetic waves, a test for both sound waves and electromagnetic waves can be performed in a single room, and a flame-retardant combustion method is used. It is characterized by using a material that does not generate toxic gas at the time.

[0005]

Embodiments of the present invention will be described below. FIG. 1 is a view for explaining an example of a sound wave and radio wave absorber according to the present invention. The radio wave absorber 1 is a flame-retardant pyramid made of flame-retardant styrofoam or phenol foam, which emits no toxic gas during combustion. Type radio wave absorber, embedded in a concave portion between the radio wave absorbers, a sound absorber 2 made of an inorganic short fiber such as an inverted quadrangular pyramid-shaped vertical or corrugated fiber glass wool, and bonded and fixed. It is flush. Figure 1 for vertical or corrugated fibers
As shown in (b) and (c), the direction of the fiber is oriented in the depth direction or the random direction of the absorber. Needless to say, the surface may not be flush and may be configured so that unevenness remains. The radio wave absorber 1 also absorbs sound waves in a certain frequency band. In this band, it also contributes to the absorption of sound waves together with the sound wave absorber 2.
Will be absorbed. In this structure, the electromagnetic wave reaches the surface of the radio wave absorber 1 through the sound absorber 2 and is absorbed as it is or is absorbed while repeating reflection on the surface. The sound wave is directly absorbed by the sound absorber 2 or is absorbed by the sound absorber in a process of repeating the reflection on the surface of the radio wave absorber 1 after passing through the sound absorber.

FIG. 2 uses a sound absorber 3 made of an inorganic short fiber such as a trapezoidal vertical or corrugated fibrous glass wool having a truncated square pyramid-shaped top, instead of the quadrangular pyramid-shaped sound absorber shown in FIG. 1 only in that the radio wave absorber 1 also absorbs sound waves in a certain frequency band, and in this band, contributes to the absorption of sound waves together with the sound absorption band 3, and the sound waves outside this band are absorbed by sound waves. The point of absorption in band 2 is the same. In the example of FIG. 2, there is an air layer between the sound absorber 3 and the radio wave absorber 1, and the sound wave is absorbed by the sound absorber 3 through this air layer while repeating reflection between the sound absorber and the radio wave absorber. Will be.

FIG. 3 shows a type in which the radio wave absorber 4 does not easily absorb sound waves like a plastic absorber. Therefore, the entire surface of the pyramid type radio wave absorber having a quadrangular pyramid shape is a horizontal or corrugated fiber formed in a hat shape. It is covered with a sound absorber 5 made of inorganic short fibers such as glass wool. In the horizontal or corrugated fibrous sound absorber, the direction of the fibers is oriented in a direction orthogonal to the depth direction of the absorber or in a random direction.

In the examples shown in FIGS. 1 to 3, an example in which a pyramid-shaped radio wave absorber is used has been described. May be provided with a sound absorber.

FIG. 4 is a plan view of the sound wave and radio wave absorber shown in FIGS. 1 to 3, wherein hatched lines indicate sound wave absorbers, and in the examples of FIGS. In the example of FIG. 3, the exposed surface has a pyramid shape.

FIG. 5 to FIG. 7 show the case of FIG. 1 and FIG.
Instead of arranging the sound absorbers on the entire surface, one provided in every other row in the vertical direction (FIG. 5), one provided in every other row in the horizontal direction (FIG. 6), and one provided in a mosaic shape (FIG. 7) It is. 1 and 2, since the radio wave absorber also absorbs the sound wave, the sound wave absorber may be distributed in a predetermined pattern at an appropriate ratio according to the required performance.

FIG. 8 is a diagram showing another example of the present invention.
8A is a perspective view, FIG. 8B is an AA side view, and FIG.
(C) is BB sectional drawing. In this example, a triangular wave absorber sheet 10 having a predetermined thickness in which carbon is contained in glass wool and a sound absorber sheet 11 made of glass wool are alternately arranged to absorb sound waves and electromagnetic waves. . Of course, the shape is not limited to a triangular shape, and may be an arbitrary polygonal shape. In addition, the thickness of the radio wave absorber sheet and the sound wave absorber sheet can be changed according to the required performance,
You may make it change the ratio of the number of sheets of each superposition.

FIG. 9 is a view showing another example of the present invention. FIG. 9 (a) is a side view, FIG. 9 (b) is a front view, and in the example of FIG. The height has been changed. That is, the highest part has the radio wave absorber sheet 20 and the sound absorber sheet 21 in a triangular shape with a predetermined thickness, and the lowest part has a trapezoidal shape by cutting off the top of the triangle. The pattern for changing the height may be appropriately selected according to the required performance, and the thickness and height of the radio wave absorber sheet and the sound wave absorber sheet may be changed,
You may make it change the ratio of the number of sheets of each superposition.

[0013]

As described above, according to the present invention, the radio wave absorber is a pyramid-shaped, wedge-shaped or polygonal sheet, and the sound wave absorber is disposed on the surface of the radio wave absorber or between the radio wave absorbers. In this way, a structure that absorbs both sound waves and electromagnetic waves was used.
It can be done in the room, so space saving,
The cost can be reduced, and a quasi-noncombustible absorber can be obtained by mainly using a material that is flame-retardant and does not generate toxic gas during combustion.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an example of a sound wave and radio wave absorber according to the present invention.

FIG. 2 is a diagram illustrating another example of a sound wave and radio wave absorber according to the present invention.

FIG. 3 is a diagram illustrating another example of a sound wave and radio wave absorber according to the present invention.

FIG. 4 is a plan view of an example in which a sound absorber is arranged on the entire surface of a radio wave absorber.

FIG. 5 is a plan view of an example in which sound wave absorbers are arranged every other row in the vertical direction.

FIG. 6 is a plan view of an example in which sound wave absorbers are arranged every other row in the horizontal direction.

FIG. 7 is a plan view of an example in which sound absorbers are arranged in a mosaic shape.

FIG. 8 is a view for explaining another example of the sound wave and radio wave absorber of the present invention.

FIG. 9 is a view for explaining another example of the sound wave and electromagnetic wave absorber of the present invention.

[Explanation of symbols]

1, 4, 10, 20 ... radio wave absorber, 2, 3, 5, 11,
21 ... Sound absorber.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masayuki Hirata 4 Otsuka Science Co., Ltd., 4 Sekitori-cho, Mizuho-ku, Nagoya-shi, Aichi (72) Inventor Osamu Yamamoto 3-13-5 Oi, Shinagawa-ku, Tokyo (72 ) Inventor Yasuhiro Ogura 5-37-7-201 Fukasawa, Setagaya-ku, Tokyo

Claims (5)

[Claims] 1. A sound absorber is embedded and fixed in a cavity between pyramid-shaped or wedge-shaped radio wave absorbers that are attached to a ceiling, a wall, or the like of an anechoic chamber or an acoustic test room. An electromagnetic wave absorber combined with a sound wave, which is made of a flame retardant material. 2. The wave absorber according to claim 1, wherein the sound absorbers embedded in the depressions between the absorbers of the wave absorber are arranged in a predetermined pattern. . 3. The entire surface of a pyramid-type or wedge-type radio wave absorber attached to a ceiling, a wall, or the like of an anechoic chamber or an acoustic test room, is covered with a sound wave absorber, and each absorber is made of a flame-retardant material. Characteristic wave absorber combined with sound wave. 4. A sound absorber sheet is sandwiched between every other or several sheets between polygonal electromagnetic wave absorber sheets whose side surfaces are attached to a ceiling, a wall, or the like of an anechoic chamber or an acoustic test chamber. An electromagnetic wave absorber combined with a sound wave, wherein the body is made of a flame retardant material. 5. The wave absorber according to claim 4, wherein the height of the wave absorber sheet and the height of the sound wave absorber sheet are different in a predetermined pattern.