JP2001306079A - Core material for sound-absorbing board and the sound- absorbing board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a core material for a sound-absorbing board which can improve sound absorptivity and the sound-absorbing board. SOLUTION: The sound-absorbing board 1 is formed, by providing the sound- absorbing board with the core material 2 for the sound-absorbing board consisting of a foamed resin, which is formed with plural projecting parts 5, etc., of a triangular shape is a section having front ends which form an acute angle on its front surface and is formed with recessed sound-absorbing parts 6 recessing to the inner side in its thickness direction on the lower ends of the projecting parts 5, etc., and superposing a porous material 3 which consists of fibers on the front surface of the core material 2 for the sound-absorbing board along the shapes of the projecting parts 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of a sound absorbing plate used for, for example, adjusting sound and reducing indoor noise.

[0002]

2. Description of the Related Art A sound absorbing plate is made of glass fiber, rock wool, asbestos, cloth, foam material and the like. The principle is that sound waves are applied to the above-mentioned air-permeable material to convert sound energy into heat or vibration to prevent reflection.

However, the sound absorbing plate is formed in a flat plate shape. That is, when a sound wave hits a boundary surface, sound not incident there is immediately reflected. So to speak, it relies on the properties of the material, and there is a limit to improving the sound absorption coefficient.

[0004]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a core material for a sound-absorbing plate and a sound-absorbing plate capable of improving the sound absorption rate by adopting a unique form capable of increasing the ratio of incident sound. Is the main issue.

[0005] Means for that purpose is a core material for a sound absorbing plate in which a plurality of projections having a shape narrower toward the front end side are formed on the surface, and the projections are formed with a concave sound absorption section which is recessed inward in the thickness direction. It is characterized by being.

In use, a porous material made of fibers or the like is suitably attached to the surface. Further, the core material for the sound absorbing plate may be formed of a material having an air layer such as a synthetic resin foam.

The sound wave is not reflected by the protruding portion that becomes narrower toward the tip, but is absorbed by the side surface of the protruding portion. A part of the sound that is not absorbed hits the side surface of the nearby protrusion as reflected sound, and is further absorbed. Then, the sound that has entered the concave sound absorbing portion is reflected inside the concave sound absorbing portion, and hardly escapes outside.

It is preferable that the protrusion has a triangular cross section with a sharp end, and that the side surface of the protrusion is formed as an inclined surface. The shape of the tip makes it easy to capture the sound to the base side of the protruding part without reflecting it, and the side surface of the protruding part can reflect some reflected sound that can not be completely incident on the side of other nearby protruding parts This is because sound absorption can be promoted without being reflected on the surface of the sound absorbing plate and emitted.

[0009] The concave sound absorbing portion may be formed at a lower end of the projecting portion. This is because it is possible to ultimately absorb the sound that is directly incident without being incident from the side surface of the protruding portion and the sound that is reflected and incident on the side surface of the protruding portion, so that it can be reflected inside and not escape to the outside. .

[0010] Furthermore, it is preferable that a wide portion wider than an upper end opening of the concave sound absorbing portion is formed in the concave sound absorbing portion. This is because the sound energy reflected in the concave sound absorbing portion can be reflected at a portion that transitions from the end of the wide portion to the upper end opening, and can hardly escape to the outside.

Further, the bottom surface of the concave sound absorbing portion formed between the projecting portions of the concave sound absorbing portion is formed as an inclined surface or a curved surface. Alternatively, it is preferable to form an upwardly projecting projection that forms a point. This is because sound directly incident without being incident on the side surface of the projecting portion can be reflected into the concave sound absorbing portion by the projecting portion without being directly reflected in the incident direction.

Another means is that the surface of the core material for a sound absorbing plate is
It is a sound absorbing plate obtained by polymerizing a porous material along the shape of the projection. The sound waves impinge on the porous material superimposed on the surface of the core material for the sound absorbing plate, where the sound is absorbed and the unabsorbed portion is reflected. The incident sound is converted into heat and vibration by the porous material, and is similarly converted by the core material for the sound absorbing plate under the porous material. The sound reflected by the porous material on the protruding portion of the core material for the sound absorbing plate in the vicinity is absorbed by the porous material and the core material for the sound absorbing plate, and the portion not absorbed is the other portion of the porous material. And is absorbed by the porous material and the core material for the sound absorbing plate at that portion.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing a part of a sound absorbing plate 1. The sound absorbing plate 1 is configured by superposing a porous material 3 on a surface of a core material 2 for a sound absorbing plate (hereinafter, referred to as a core material).

The porous material 3 converts sound waves into heat and vibration, and has a large number of fine holes so that a contact area with the sound waves can be increased. What is necessary is just to laminate a large number of appropriate fibers and to perform flat compression molding. It is preferable to use an acetate fiber as the fiber, because the acetate fiber has a Y-shaped cross section, so that a large number of fine holes suitable for sound absorption can be formed by being entangled with each other.

The core 2 supports the flexible porous material 3 and prevents transmission of vibration energy converted from incident sound incident on the porous material 3. Since it is preferable that the air layer is formed, the material is preferably formed of a synthetic resin foam. In addition, a large number of air layers may be formed of wood, metal, or the like, but synthetic resin is more preferable because it is lighter in weight and can be formed by extrusion or the like and is simple.

The shape of the core 2 is such that a large number of strip-shaped protrusions 5 having a triangular cross section are arranged on a flat base 4. The shape of the projection 5 is preferably such that the two inclined surfaces 5a, 5a forming a triangle have a large inclination angle. For example,
It is preferable that the slope is steeper than when the ratio of the base to the height is 2: 3, but it is more preferable that the ratio is about 1: 2 or more.

At the lower end of the projection 5, the base 4
A concave sound absorbing portion 6 that is recessed inside in the thickness direction is formed.
The concave sound absorbing portion 6 is formed by digging round from the lower end of the projecting portion 5 to the lower side of the projecting portion 5, and is set such that the end of the concave sound absorbing portion 6 is located inside the lower end position of the projecting portion 5. are doing. That is, the wide portion 6b wider than the upper end opening 6a is formed. In addition, the concave sound absorbing portion 6 is formed in a circular cross section,
The center of the circle is preferably located inside the end of the upper end opening 6a. This is because the ceiling surface 6c of the concave sound absorbing portion 6 draws a circular arc, so that the operation and effect described later can be further ensured. Also,
The concave sound absorbing surface 6 may be formed in a polygonal cross section only by an inclined surface having no flat surface parallel to the surface direction of the sound absorbing plate 1, or may be formed by combining an inclined surface and a curved surface. further,
The concave sound absorbing portion 6 may be formed on the inclined surface 5 a of the projection 5.

Further, on the bottom surface of the concave sound absorbing portion 6 located between the protrusions 5, a portion corresponding to the upper end opening 6 a of the concave sound absorbing portion 6 has a line similar to the front end of the protrusion 5. An upwardly projecting projection 6d is formed. Thus, the sound that is linearly incident on the concave sound absorbing portion 6 is reflected in the concave sound absorbing portion 6 on both left and right sides of the protrusion 6d without being reflected in the incident direction. Due to this reflection and the formation of the wide portion 6b and the formation of the ceiling surface 6c, it is difficult for the reflected sound to go out of the concave sound absorbing portion 6.

With respect to the core material 2 formed in such a shape,
By attaching the porous material 3 with an adhesive, the sound absorbing plate 1 can be formed. The porous material 3 is set to an appropriate thickness such as 10 cm, for example, and polymerizes along the protrusion 5 of the core material 2. In the drawing,
Although the porous sound absorbing member 6 is filled with the porous material 3, the sheet-shaped porous material 3 is adhered to the upper end opening 6 a of the concave sound absorbing portion 6.
, The concave sound absorbing portion 6 may be formed in a cavity.

In use, the back surface of the core material 2 is fixed to a used portion such as a wall surface.

FIG. 2 is an explanatory view showing an operation state of the sound absorbing plate 1 configured as described above. That is, the protrusion 5 of the core 2
Is formed in a triangular shape whose width becomes narrower toward the front end side, and the front end portion of the porous material 3 polymerized along the triangular shape has the same shape. Therefore, as shown on the left and right sides of FIG.
The sound wave is not reflected in the incident direction as it is at the tip of the porous material 3, but hits the porous material 3 that has polymerized on the inclined surface 5 a of the protrusion 5, and is absorbed by the porous material 3. The sound energy absorbed by the porous material 3 is converted into heat and vibration, and the core material 2 is similarly attenuated. Part of the unabsorbed portion is reflected as reflected sound toward the base side of the protrusion 5 and hits the porous material 3 superimposed on the protrusion 5 inclined surface 5a located in the vicinity. Further sound absorption is performed with the core material 2 in the lower layer. The above operation is appropriately performed depending on the incident angle, and the incoming sound is successively absorbed and attenuated.

Then, the direct incidence or the inclined surface 5 of the core 2
a The sound incident on the concave sound absorbing portion 6 through the porous material 3 due to the reflection on the porous material 3 in the upper layer is reflected inside the concave sound absorbing portion 6 as shown in the center of FIG. It becomes difficult to escape and is attenuated in the process of reflection.

That is, the sound coming from the front side is captured by the protrusion 5 of the core material 2, the porous material 3 on the upper surface thereof, and the periphery thereof, and is surely converted into heat and vibration without being released to the surface, thereby absorbing the sound. .

The sound absorbing plate 1 shown in FIG. 3 is obtained by polymerizing a glass fiber cloth 7 on the surface of the porous material 3 so as to obtain strength, decorativeness, flame resistance, and water resistance. An example is shown in which a decorative plate 8 is attached to the back surface of the core material 2.

FIG. 4 shows an example of the sound absorbing plate 1 which can be reduced in thickness. That is, on the base 2 of the core material 2, a large number of protrusions 5 having a shorter base than the previous example are formed, and the lengths of the opposed inclined surfaces 5b and 5c of each of the protrusions 5 are alternately set by one set of long and short. At the lower end of the long inclined surface 5b, a concave sound absorbing portion 6 of the same size as the previous example is formed, and at the lower end of the short inclined surface 5c, a smaller concave sound absorbing portion 6 is formed. are doing. The porous material 3 is polymerized on the surface of the core material 2 while filling the concave sound absorbing portions 6.

FIG. 5 shows an example of the sound-absorbing plate 1 which makes it easy to absorb even a sound entering obliquely. That is, the core material 2
The projections 5 formed on the upper and lower parts are two
Types are alternately formed, and a concave sound absorbing portion 6 is formed at the lower end of each protrusion 5. The porous material 3 is polymerized on the surface. Since the interval between the high protrusions 5 is wide, it is easy to catch the sound entering obliquely, and the sound reflected without being absorbed even if it is caught is low in the height of the low protrusion 5 or its adjacent height. It hits the base side of the high protrusion 5 and is absorbed in order.

In construction, not only one kind of sound absorbing plate 1 but also various types of sound absorbing plates 1 formed as described above may be combined.

[0028]

As described above, according to the present invention, the protrusion formed on the core material for the sound absorbing plate absorbs the hitting sound without reflecting it in the incident direction. The portion that cannot be completely incident is reflected on the base side of the protruding portion, where it is further absorbed, and the reflected portion is reflected on another protruding portion or the concave sound absorbing portion, and further absorbed there. That is, the sound that enters from the front end side of the protruding portion is captured in the protruding portion or between the protruding portions without being released to the front, and is reliably converted into heat or vibration to be attenuated to absorb sound. For this reason, the sound absorption coefficient can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view of a sound absorbing plate.

FIG. 2 is a schematic diagram of an operation state of a sound absorbing plate.

FIG. 3 is a sectional view of another example of the sound absorbing plate.

FIG. 4 is a sectional view of another example of the sound absorbing plate.

FIG. 5 is a sectional view of another example of the sound absorbing plate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Sound absorption plate 2 ... Core material for sound absorption plates 3 ... Porous material 5 ... Protrusion 5a, 5b, 5c ... Inclination surface 6 ... Concave sound absorption part 6a ... Top opening 6b ... Wide part 6c ... Ceiling surface 6d ... Projection

Claims (6)

[Claims] 1. A core material for a sound absorbing plate, wherein a plurality of protrusions having a shape narrower toward the front end side are formed on a surface thereof, and the protrusions have a concave sound absorbing portion recessed inward in the thickness direction. 2. The core material for a sound-absorbing plate according to claim 1, wherein said projection has a triangular cross section in which a tip portion forms an acute angle, and a side surface of said projection is formed as an inclined surface. 3. The core material for a sound absorbing plate according to claim 1, wherein said concave sound absorbing portion is formed at a lower end portion of said projecting portion. 4. The core material for a sound-absorbing plate according to claim 1, wherein the concave sound-absorbing portion has a wide portion wider than an upper end opening of the concave sound-absorbing portion. . 5. A bottom surface of the concave sound absorbing portion formed between the protruding portions of the concave sound absorbing portion is formed as an inclined surface or a curved surface, and at the bottom corresponding to the upper end opening of the concave sound absorbing portion.
The core material for a sound-absorbing plate according to any one of claims 1 to 4, wherein an upwardly projecting projection having a front end forming a line or a point is formed. 6. A sound absorbing plate wherein a porous material is superposed on the surface of the core material for a sound absorbing plate according to any one of claims 1 to 5 along the shape of the projection.