WO1997024496A1

WO1997024496A1 - Honeycomb soundproofing board

Info

Publication number: WO1997024496A1
Application number: PCT/KR1996/000044
Authority: WO
Inventors: Soung-Soo Han
Original assignee: Korea Sound Absorption Corporation
Priority date: 1995-12-29
Filing date: 1996-04-04
Publication date: 1997-07-10
Also published as: AU5289796A

Abstract

A honeycomb soundproofing board is disclosed. The soundproofing board has a plurality of conical muffler cells (15) uniformly and densely arrayed in layers and lines in the board. The muffler cell (15) has a rectangular mouth (12) suitable to minimize the boundary area of the board's front surface, so the board almost totally prevents the noise sound waves from being reflected by the board's front surface. The board effectively suppresses noise and improves the soundproofing effect. The board also prevents resonance of the sound waves in the conical muffler cells (15). The conical muffler cells (15) are either provided with wedge steps (16), charged with sound absorbing materials or formed in both sides of the board to further improve the soundproofing effect.

Description

HONEYCOMB SOUNDPROOFING BOARD

Technical Field

The present invention relates in general to honeycomb soundproofing boards for absorbing and reducing indoor noises such as noises from machine rooms, music halls or from living space and/or outdoor noises such as street noises and, more particularly, to a structural improvement in such soundproofing boards for improving the soundproofing effect of the boards.

Background Art

As well known to those skilled in the art, noise has an effect of upsetting people. Due to industrial development, noise in dwelling areas as well as noise in business or industrial districts has become an issue. In recent years, street noise has become much worse due to increased traffic.

In an effort to reduce or suppress such noises, various types of soundproofing boards have been used. In the prior art, uni- or bi-ply boards formed of sound absorbing materials have been generally used as the soundproofing boards. However, the typical soundproofing boards having the uni- or bi-ply construction require a large installation space. The above soundproofing boards also partially reflect and/or pass noise, thereby failing to effectively reduce noise.

In order to overcome the above problems, Korean U.M. Appln. No. 95-9151 discloses a soundproofing board. The above Korean soundproofing board includes a dissipative unit that dissipates the sound waves and converts the sound waves into vibrational energy. The above dissipative unit is backed by a soundproofing unit. The above soundproofing unit includes a vibrational energy buffer for absorbing the vibrational energy generated by the dissipative unit. The above soundproofing unit also includes two types of panels, that is, a sound absorbing panel and a gypsum panel. The sound absorbing panel absorbs the remaiϋing sound waves, while the gypsum panel intercepts the sound waves to prevent the sound waves from passing the board. In the above Korean soundproofing board, the noise sound waves are dissipated and converted into vibrational energy by the dissipative unit. The vibrational energy in turn is absorbed by both the vibrational energy buffer and the sound absorbing panel of the soundproofing unit. The remaining waves are intercepted by the gypsum panel thereby being prevented from passing the board.

However, the above Korean soundproofing board has the following problems. That is, the dissipative unit partially reflects the sound waves of noises, so the soundproofing board fails to completely absorb and suppress noise. In the above soundproofing board, the noise sound waves are absorbed and suppressed by the laminated panels, so the board is difficult to produce and is expensive. The above board also requires a large installation space thus failing to solve the above- described space problem.

Korean U.M. Appln. No. 91-2415 discloses another type of soundproofing board. The interior of the above soundproofing board sided by outer walls are partitioned into a plurality of cells. Both a plurality of cones for receiving noise sound waves and a plurality of main sound mufflers having a circular configuration are continuously placed in the above board. A subsidiary sound muffler is formed on the side of each cone. The cones guide the noise sound waves into the main sound mufflers for breaking the sound waves. The noise sound waves are also suppressed in the subsidiary sound mufflers.

The soundproofing board disclosed in Korean ϋ.M. Appln. No. 91-2415 somewhat effectively prevents the sound waves from being reflected by the front surface of the board. However, the sound waves guided into the main sound mufflers nonuniformly bump against the internal walls of the mufflers, so the waves are partially reflected outside the board through the cells. The sound waves guided into the subsidiary sound buffers are also partially reflected outside the board. The above soundproofing board thus fails to completely suppress the noise. In addition, the sound waves resonate in the main and subsidiary sound mufflers as the waves nonuniformly bump against the internal walls of the mufflers. In addition, it is difficult to integrally form the cones and the main sound mufflers of the above soundproofing board, so the cones and main sound mufflers must be formed separately prior to being assembled into a board.

Description of the Invention

It is, therefore, an object of the present invention to provide a honeycomb soundproofing board in which the above problems can be overcome. The above soundproofing board has a plurality of conical muffler cells which are uniformly and densely arrayed in layers and lines in the board and have rectangular mouths suitable to minimize the boundary area of the board's front surface, so the board almost prevents the sound waves from being reflected by the board's front surface, thus more effectively breaking the sound waves and improving the soundproofing effect. The soundproofing board also prevents resonance of the sound waves in the conical muffler cells and is easily produced at a low cost.

It is another object of the present invention to provide a honeycomb soundproofing board whose conical muffler cells are either provided with wedge steps, charged with sound absorbing materials or formed in both sides of the board to further improve the soundproofing effect of the board.

In order to accomplish the above objects, the present invention provides a honeycomb soundproofing board comprising: a plurality of sound arresting units uniformly and densely arrayed in layers and lines in the board to form a honeycomb construction. Each sound arresting unit includes a mouth having a rectangular configuration buitable to minimize a boundary area of a board's front surface, and a conical sound muffler cell extending backward from the rectangular mouth to form a vertex in a rear portion of the board.

Brief Description of the Drawings

The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

Fig. 1 is a perspective view of a honeycomb soundproofing board in accordance with a primary embodiment of the present invention;

Fig. 2 is a partially sectioned view of the above soundproofing board, showing the configuration of each sound arresting unit of the board;

Fig. 3 is a sectional view taken along the section line A-A of Fig. 1, showing the construction of the above soundproofing board;

Fig. 4 is a sectional view of the above soundproofing board showing the operational effect of the board; and

Figs. 5 to 9 are views corresponding to Fig. 3, but showing the constructions of honeycomb soundproofing boards in accordance with other embodiments of the present invention, respectively.

Best Mode for Carrying Out the Invention

Figs. 1 to 4 show a honeycomb soundproofing board in accordance with a primary embodiment of this invention. As shown in the drawings, the soundproofing board includes a plurality of sound arresting units 10 that are uniformly and densely arrayed in layers and lines in the board to form a honeycomb construction. Each unit 10 has a rectangular mouth 12 opening forward. The rectangular configuration of each mouth 12 minimizes the boundary area of the board's front surface, thus almost completely preventing sound waves of noises from being reflected by the board's front surface as will be described in detail later herein. A conical sound muffler cell 15 extends backward from each rectangular mouth 12. The vertex of each conical muffler cell 15 is placed in the rear portion of the board as shown Figs. 2 and 3.

Figs. 5 to 9 show honeycomb soundproofing boards in accordance with other embodiments of the present invention, respectively.

In the embodiments of Figs. 5 and 6, the interior wall of each conical muffler cell 15 is stepped several times, preferably two times, thus to form wedge steps 16. Due to the wedge steps 16, the sound waves of noises are stepwisely and repeatedly suppressed by the internal wall of each cell 15. In the embodiment of Fig. 6, the general shape of the conical muffler cell 15 remains the same as in the embodiment of Fig. 5, but the wedge step 16 is altered to form a recess 16b by forming an extending edge 16a. The edge 16a extends toward the vertex 19 to form the recess 16b in each wedge step 16.

In the embodiment of Fig. 7, a sound absorbing material 20 suitable to absorb the sound waves of noises while passing the waves is charged in each conical muffler cell 15. The above sound absorbing material 20 is thinly charged in the cell's front portion about the mouth 12, but it is densely charged in the cell's rear portion about the vertex 19. The soundproofing board according to the embodiment of Fig. 7 further improves both the resonance preventing effect and the soundproofing effect. In the embodiments of Figs. 8 and 9, the sound arresting units are formed in the front and rear portions of the board to absorb noises on both sides of the board. In the soundproofing board according to the embodiment of Fig. 8, a plurality of rear sound arresting units 10' are formed in the rear portion of the board to be disposed between the front sound arresting units 10. The rectangular mouth 12 of each rear unit 10' opens backward. In the soundproofing board according to the embodiment of Fig. 9, the plurality of rear sound arresting units 10" that are formed in the rear portion of the board are opposite to the front sound arresting units 10. A vertical cavity 18 that is charged with a sound absorbing material 20 is commonly formed in the vertexes of the front and rear units 10 and 10". That is, the units 10 and 10" are commonly backed by the sound absorbing material 20.

In the above-described embodiments shown in Figs. 1 to 9 , each sound arresting unit of the soundproofing board has the conical muffler cell and rectangular mouth. However, it should be understood that the sound arresting unit may have a pyramidal muffler cell extending from the rectangular mouth. In addition, the soundproofing board of this invention may be formed of a transparent material. The transparent soundproofing board may be preferably installed on the roadside since such a soundproofing board does not cast its shadow on the road.

The operational effect of the above honeycomb soundproofing board will be described hereinbelow.

The soundproofing board according to the primary embodiment of Figs. 1 to 4 is installed on the roadside or on the wall of a machine room such that the front, surface with the sound arresting units 10 is directed to the noise source.

Since the boundary area of the board's front surface is minimized due to the rectangular mouths 12 that are uniformly and densely arrayed in layers and lines on the board's front surface, the sound waves are scarcely reflected by the board's front surface. But the noise sound waves are almost totally guided into the conical muffler cells 15 through the rectangular mouths 12.

As shown in Fig. 4, the sound waves guided into the muffler cells 15 are repeatedly reflected by the side walls of the cells 15. The sound waves in the above state are reflected toward the vertex 19 of each muffler cell 15, so the sound waves are not reflected outside the board but totally suppressed in the cells 15. The above honeycomb soundproofing board thus improves the soundproofing effect.

In the soundproofing board according to the embodiment of Fig. 5, a part of the noise sound waves guided into the muffler cells 15 are stepwisely muffled by the wedge steps 16, so the soundproofing board of this embodiment further improves the soundproofing effect. In the embodiment of Fig. 6, each wedge step 16 is provided with the recess 16b by the extending edge 16a, so the sound waves guided into the step 16 are not reflected outside the step 16 but totally suppressed in the step 16.

In the soundproofing board according to the embodiment of Fig. 7, the conical muffler cells 15 are charged with the sound absorbing material 20. The sound waves guided into each cell 15 are primarily weakened by the thinly charged sound absorbing material 20 in the cell's front portion prior to being completely absorbed and suppressed by the densely charged sound absorbing material 20 in the cell's rear portion. Due to the above sound absorbing material 20, the sound waves of noises are prevented from resonating in the cells 15. In the above embodiment, the sound absorbing material 20 charged in each muffler cell 15 may somewhat project out of the mouth 12. The soundproofing board that has somewhat projecting sound absorbing material 20 has a further improved design and operational effect.

The soundproofing boards according to the embodiments of Figs. 8 and 9 have the front and rear sound arresting units that are formed in the front and rear portions of the board, so the above soundproofing boards can be preferably used for absorbing noises on both sides of the boards. In the board according to the embodiment of Fig. 8, the rear sound arresting units 10' are formed in the rear portion of the board to be disposed between the front sound arresting units 10. The soundproofing board of Fig. 8 thus effectively absorbs noises on its both sides at the same time without increasing the thickness of the board. In the board of Fig. 9, the rear sound arresting units 10" are formed in the rear portion of the board to be opposite to the front sound arresting units 10. In addition, the vertical cavity 18 that is charged with the sound absorbing material 20 is commonly formed in the vertexes of the front and rear units 10 and 10". The sound waves guided into the muffler cells 15 of the front and rear units 10 and 10" are stepwisely weakened while they are reflected by the internal walls of the muffler cells 15. The weakened sound waves in turn are completely absorbed and suppressed by the sound absorbing material 20.

Industrial Applicability

As described above, the present invention provides a honeycomb soundproofing board suitable for absorbing and reducing indoor noises such as noise from machine rooms, music halls or from living space and/or outdoor noises such as street noise. The above board almost completely suppresses the noises while scarcely reflecting the noise sound waves thus highly improving the soundproofing effect. The soundproofing board prevents the resonance of the sound waves and has a simple construction. Due to the simple construction, the board can be easily produced at a low cost.

Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims

1. A honeycomb soundproofing board comprising: a plurality of sound arresting units uniformly and densely arrayed in layers and lines in said board to form a honeycomb construction, each sound arresting unit including: an opening mouth having a rectangular configuration suitable to mi.iiraize a boundary area of a board's front surface; and a conical sound muffler cell extending backward from said rectangular mouth to form a vertex in a rear portion of said board.

2. The honeycomb soundproofing board according to claim 1, wherein each conical muffler cell is repeatedly stepped on its interior wall to form a plurality of wedge steps for stepwisely suppressing noises.

3. The honeycomb soundproofing board according to claim 2, wherein a recess is formed in each wedge step by extending an edge of the wedge step toward the vertex.

4. The honeycomb soundproofing board according to any one of claims 1 to 3, wherein each conical muffler cell is charged with a sound absorbing material.

5. The honeycomb soundproofing board according to any one of claims 1 to 3, wherein said sound arresting units are formed in front and rear portions of said board to form front and rear sound arresting units, said rear sound arresting units being disposed between the front sound arresting units.

6. The honeycomb soundproofing board according to any one of claims 1 to 3, wherein said sound arresting units are formed in front and rear portions of said board to form front and rear sound arresting units, said rear sound arresting units being opposite to the front sound arresting units respectively, and a vertical cavity charged with a sound absorbing material is commonly formed in the vertexes of said front and rear sound arresting units.