JPH0435584B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a sound absorbing material, and particularly to a sound absorbing material that can be easily attached directly to a soundproof wall and a structure thereof.

<Prior Art> Conventionally, sound absorbing materials such as rock wool, glass wool, or ceramics have been attached directly to sound insulating materials without providing an air layer, and have had the property of having good sound absorption efficiency. The reason is that these materials can be made into extremely thick materials.

On the other hand, rock wool, glass wool, etc.
Since it is a so-called soft porous material, it requires a front plate, such as a punched metal material, to fix it, and it also has the disadvantage of being weak in fire protection, and absorbing moisture, reducing its sound absorption properties. It was hot.

Additionally, ceramic materials have the disadvantage of being heavy and weak against impact.

Al (aluminum) sintered plates appeared to solve the various drawbacks mentioned above, and they also have good workability.
An Al porous plate made by rolling an Al-based metal nonwoven fabric into an expanded metal sandwich has appeared.

However, since these Al porous plates are thin materials with a thickness of 2 to 3 mm, in order to achieve the same level of sound absorption effect as a thick soft porous material, it is necessary to provide an air layer of the same level.

To this end, as shown in FIG. 8, a method has been adopted in which a channel 6 is provided on a sound insulating wall 23 and a porous metal material 1 such as Al is fixed thereon to provide an air layer. Therefore, these frameworks have become expensive.

<Problems to be Solved by the Invention> An object of the present invention is to solve the above-mentioned problems of the prior art and provide a sound-absorbing material and a sound-absorbing structure that are easy to install and have a shape with good sound absorption efficiency. .

<Structure of the Invention> A first aspect of the present invention is a porous metal material composed of a laminated and pressed body of an Al-based expanded metal and an Al-based metal fiber layer, which has a convex portion that defines a sound-absorbing space inside. and a mounting recess.

A second aspect of the present invention is a sound-absorbing structure in which a sound-absorbing material is fixed to a structure, wherein the sound-absorbing material is a porous metal material made of a laminated and pressed body of an Al-based expanded metal and an Al-based metal fiber layer. and has a convex part that limits a sound absorption space inside and a recessed part for mounting,
To provide a sound-absorbing structure, characterized in that when the sound-absorbing material is fixed between its mounting recess and the structure, a soft porous material is disposed between the sound-absorbing material and the structure.

Further, a sound absorbing material in which the Al-based metal fibers are manufactured from molten Al-based metal by a spinning method is preferable.

The present invention will be explained in detail below.

Al (aluminum) expanded metal and Al
As shown in the cross-sectional view in FIG. 3, the laminated and crimped body with the metal fiber layer is made by forming the metal fiber layer into a layer to form the metal fiber layer 2, and laminating this with the expanded metal 3. It is crimped.

Expanded metal, as shown in the perspective view in Figure 5, is usually called lath netting or punching metal, and is made by making a number of cuts in a thin metal plate and pulling the cuts in a substantially perpendicular direction to form a net-like shape. say. Expanded metal is not made of thin metal wires woven like a metal net, so the cut cross section of the thin metal sheet is twisted by tensile force and may shift not only at right angles to the plane of the thin metal sheet, but also in parallel, diagonal, etc. Because of the twisted portion, when the metal fiber layer 2 is pressed onto this, the intertwining with the metal fiber layer 2 is good.

The present invention applies an Al-based expanded metal made of an Al-based material as such expanded metal.

Further, the shape may be a punched metal having similar pores, or a metal wire mesh.

There is no particular restriction on the plate thickness, but a plate thickness of 0.2 mm to 1 mm is usually used.

If the degree of processing such as cutting and tensioning is selected appropriately depending on the shape and type of the Al-based metal fiber, porous metal can be created with good pressure and adhesion between the expanded Al-based metal and the Al-based metal fiber. wood is obtained.

The Al-based metal fibers forming the metal fiber layer 2 are Al
A fibrous metal with a cross section of any shape, such as a triangle or circle, and an effective diameter of approximately 20 to 200 μm.
m, a general term for Al-based metal strips with a length of 1 to 20 cm.

One example of the method for producing Al-based metal fibers is as follows: Machining method by drawing How to spin from molten metal etc.

In particular, when Al-based metal fibers spun from molten Al-based metal are used as Al-based metal fibers, the metal fibers are thin and flexible, and mesh well with Al-based expanded metal, so they can be used for sound-absorbing materials after bending. It is safe from an environmental and hygienic point of view, as fine metal pieces do not chip off during the process.

The porous metal material 1 is manufactured as follows using the above-mentioned Al-based expanded metal, metal mesh, and metal fiber.

Areal density of Al-based metal fibers is 500g/m ² to 3000g/m ²
Make it into a non-woven fabric.

Al-based expanded metal is applied to one or both sides of this non-woven Al-based metal fiber, and the laminate of this Al-based metal fiber and expanded metal is
It is pressed or rolled at Kg/cm ² to 2000 Kg/cm ² and crimped.

Al-based metal fibers are fibers with a diameter of 70 to 250 μmφ, and have an average tensile strength of approximately 25 Kg/cm ² and an elongation of 10 to 250 μm.
20%, so if a laminate is formed with Al-based expanded metal and pressed or rolled,
Al-based expanded metal bites into Al-based metal fibers and adheres closely.

Al has an elongation of 10 to 20% and has little elastic strain due to plastic deformation, so plastic deformation occurs freely without causing elastic deformation due to compression.

Furthermore, the Al-based expanded metal is made into the Al-based expanded metal 3 by cold-rolling an Al plate, and then partially cutting and stretching it. Tensile strength is 50-70
Kg/mm ² , which is subjected to compressive and shear stress, and the Al-based metal fibers and the Al-based expanded metal are brought into close contact with each other.

The Al-based expanded metal 3 is preferably Al
It is made into a laminated crimped body by stretching both sides of metal fibers.
Al-based metal fibers may be pressed onto one or both sides of the Al-based expanded metal 3 to form a laminate.

Alternatively, the Al-based expanded metal 3 may be applied to one side of the Al-based metal fiber layer 2, and the other side may be made of wire mesh.

Further, when rolling the laminate using a press or roll having protrusions on the surface, the laminate partially undergoes further compression. A quality metal material 1 is produced, and the metal fiber layer 2 is also partially compressed (partial compression method). For this reason, the metal undergoes compression processing so that the distance between atoms becomes closer, further increasing the adhesion strength.

The protrusions on the press or roll surface are 10 to 2 mm spherical or elliptical protrusions on the roll surface.
It is preferable to provide it at a ratio of 1 to 2 cm ² per cm ² .

Moreover, if necessary, heat of 400 to 550° C. may be applied to sinter. When the partial compression method and the sintering method are used, the compressed portion is sintered, so that the adhesiveness between the Al-based expanded metal 3 and the Al-based metal fiber layer 2 becomes even better.

Preferred embodiments of the sound absorbing material 10 of the present invention are shown in FIGS.
Shown in Figure 1c.

The sound absorbing material 10 of the present invention is the porous metal material 1 described above.
is formed into a plate-like body having a convex portion 21 whose interior becomes a sound-absorbing space 19 and a recessed portion 22 for mounting.

Shaping can be easily carried out by ordinary rolling, bending, etc. The convex portion 21 and the concave portion 22 may have any shape.

FIG. 1a shows a shape having a trapezoidal convex portion 21 and an inverted trapezoidal concave portion 22 (so-called hat shape). However, the recess 22 is attached to the sound insulating wall 23 with a mounting tool 18 such as a screw (not shown).

FIG. 1b shows a convex portion 21 and a concave portion 22 formed in a wave-like shape, where the mountain-shaped waves have a sound-absorbing space 19 between them and the sound insulating wall 23, and the bottom of the valley-shaped concave portion 22 is provided with a mounting device such as a screw. It is attached to the sound insulating wall 23 by 18.

FIG. 1c shows an example in which a triangular convex portion 21 and an inverted trapezoidal concave portion 22 are formed.

With such a sound absorbing material 10, the surface area of the sound absorbing material per unit area of the sound insulating wall 23 increases, the sound receiving area increases, and the sound absorbing space increases, so that the sound absorbing efficiency is improved.

The sound absorbing structure 15 of the second aspect of the present invention has a second
As shown in FIGS. 2A and 2B, a soft porous material 5 is provided in the sound absorption space 19 between the sound insulation wall 23 and the sound absorption material 10.

The soft porous material 5 may be any material commonly used as a soundproof packing material, such as rock wool or glass wool.

The soft porous material 5 is preferably
As shown in Figure b, it is provided so that there is a gap between it and the porous metal material 1. When provided in this way, the soft porous material 5 does not come into direct contact with the outer surface of the sound absorbing material 10, so the soft porous material 5 does not absorb moisture such as rainwater and its sound absorbing performance does not deteriorate. Further, since the porous metal material 1 serves as a protective wall and a mounting member for the soft porous material 5, the sound absorption properties are improved, mechanical strength is improved, and construction workability is improved.

<Example> The present invention will be specifically described below with reference to Examples.

(Example 1) Al metal fiber nonwoven fabric (area density 550 g/m ² ) was made of 0.5 mm thick Al based expanded metal (center distance in the short direction of the mesh x center distance in the long direction = 4 mm)
x 8mm) between the top and bottom surfaces, air flow resistance 68g/
An Al porous metal material having a thickness of 2.5 mm and having a porosity of 60% was prepared. This was press-molded into the shape shown in FIG. 1a to obtain a sound absorbing structure as Example ¹ of the present invention.

(Comparative Example 1) For comparison, the same Al porous metal material as in Example 1 was used to make the sound absorbing material shown in FIG. 8 without changing its flat plate shape. Channel 6 is made of steel plate with a thickness of 1.6 mm and a width of 30 mm.
mm, height 50 mm, and was attached to the sound insulating wall 23.

(Example 2) Glass wool having a density of 32 kg/m ³ was attached to a sound absorbing structure similar to that of Example 1 to a thickness of 25 mm as shown in FIG. 2a to obtain Example 2 of the present invention.

(Comparative Example 2) Comparative Example 2 was obtained by attaching the same glass wool as in Example 2 to Comparative Example 1 shown in FIG. 8 to a thickness of 25 mm.

Reverberation room test Using Examples 1 and 2 and Comparative Examples 1 and 2
A reverberation chamber test was conducted according to JISA1409-1967. The results are shown in FIGS. 6 and 7.

<Effects of the Invention> In the present invention, since the porous metal material is formed into a shape having predetermined convex portions and concave portions, the sound receiving area is increased and the sound absorption characteristics are improved. It is unnecessary, can be easily installed directly, and is inexpensive.

In addition, if the structure includes a soft porous material, the sound absorption properties will be further improved, and the soft porous material will not absorb moisture such as rainwater and cause a decrease in sound absorption performance, and the mechanical strength will be improved, making it easier to install. Good sex.

[Brief explanation of drawings]

FIGS. 1a, 1b and 1c are cross-sectional views showing embodiments of the present invention, respectively. Figures 2a and 2b are cross-sectional views showing other embodiments of the invention. FIG. 3 is a cross-sectional view of the porous metal material. FIG. 4 is a cross-sectional view of a porous metal material obtained by a partial compression method. FIG. 5 is a perspective view showing expanded metal. Figures 6 and 7 are
It is a graph showing the measurement results of Examples and Comparative Examples. FIG. 8 is a diagram showing a conventional example. Explanation of symbols, 1...Porous metal material, 2...Al
-based metal fiber layer, 3... Al-based expanded metal,
5... Soft porous material, 6... Channel, 7...
Twisted part, 8... Compression part, 10... Sound absorbing material, 1
5... Sound absorbing structure, 18... Mounting tool, 19... Sound absorbing space, 21... Convex portion, 22... Concave portion, 23...
wall.

Claims (1)

[Claims] 1. A porous metal material composed of a laminated and crimped body of Al-based expanded metal and Al-based metal fiber layer, which has a convex portion that defines a sound absorption space inside and a recessed portion for mounting. A sound absorbing material characterized by having: 2. The sound absorbing material according to claim 1, wherein the Al-based metal fiber is produced from molten Al-based metal by a spinning method. 3. In a sound-absorbing structure in which a sound-absorbing material is fixed to a structure, the sound-absorbing material is made of Al-based expanded metal.
It is a porous metal material composed of a laminated and crimped body with an Al-based metal fiber layer, and has a convex portion that limits a sound-absorbing space inside and a mounting recess, and the sound-absorbing material is attached to the mounting recess and the structure. 1. A sound-absorbing structure, characterized in that a soft porous material is disposed between the sound-absorbing material and the body structure when the sound-absorbing material and the structure are fixed together. 4. The sound absorbing structure according to claim 3, wherein the Al-based metal fiber is manufactured from molten Al-based metal by a spinning method.