KR102101541B1 - Active control sound proof mat wall comprising rice hulls - Google Patents

Abstract

The present invention relates to an active control sound-absorbing mat capable of varying the thickness of the rice husk sound absorbing layer, the size of the rice husk and the density of the rice husk according to a specific noise frequency of the road, and a soundproofing wall including the same.
The present invention can provide a sound absorbing mat that is easy to recycle or dispose of the sound absorbing material because it does not use a toxic polymer adhesive and is not molded into a plate at high temperature and high pressure.
The sound absorbing mat of the present invention can control the sound absorption rate of the rice hull sound absorbing layer by adjusting the thickness of the housing portion or the specific gravity of the rice hull, so that it is possible to provide a sound absorbing material capable of actively absorbing sound according to the frequency of the noise source.
The sound-absorbing mat of the present invention is environmentally friendly because it uses rice husks that are easy to supply and receive and are free of disposal as a sound absorbing material. In addition, the sound-absorbing mat of the present invention has a uniform particle size and uses an elastic chaff in a three-dimensional shape, so it can be used as an active sound absorbing material as well as showing high sound absorption properties.

Description

Active control sound proof mat wall comprising rice hulls}

The present invention relates to an active control sound-absorbing mat comprising chaff and a soundproofing wall comprising the same, more specifically, active control capable of varying the thickness, chaff size and chaff filling density of the chaff sound absorbing layer according to a specific noise frequency of the road. A sound absorbing mat and a soundproofing wall comprising the same.

Sound barriers are installed to reduce traffic noise and traffic damage caused by road noise adjacent to houses.

The soundproofing wall is divided into a diffractive soundproofing wall that reduces noise by sound reflection and a soundproofing soundproofing wall that reduces noise by sound absorption and soundproofing. The sound-absorbing sound-absorbing wall is made of aluminum or plastic, and a glass fiber or porous polyester fiber is put in it to obtain a sound-absorbing effect. However, glass fiber is difficult to handle and harmful to the human body due to dust emission, polyester fiber is vulnerable to fire, and is harmful to the human body by emitting carbon dioxide or volatile organic compounds (VOCs) during manufacturing and disposal. Accordingly, it is necessary to develop a soundproof wall using eco-friendly materials.

Republic of Korea Patent Publication No. 10-2013-0077586 discloses a sound-absorbing material by compression molding by mixing sawdust and rice husk and injecting an adhesive therein. Since the disclosed patent mainly uses sawdust and rice husk, additional pollution does not occur during disposal, and can be recycled to provide an environmentally sound insulation material. However, the disclosed patent uses pressure-forming at a high temperature using a phenol resin adhesive as an adhesive, so it is still difficult to recycle the sound absorbing material, and environmental pollution or toxicity caused by the adhesive remains. In addition, the disclosed patent has a fundamental problem that it is not possible to change the sound absorption rate of the sound absorbing material that has already been produced because the adhesive is mixed with sawdust and rice husk and compressed to produce a board.

The present invention is to provide an environmentally friendly sound absorbing mat without the use of an adhesive.

The present invention is to provide an active control sound absorption mat capable of sound absorption according to the frequency of the noise source.

One aspect of the invention

Thickness adjustable housing portion 10; And

As a sound absorbing mat comprising a chaff sound absorbing layer 20 packed in the housing portion,

The sound absorption mat is related to an active control sound absorption mat that controls the sound absorption rate of the chaff sound absorption layer by adjusting the thickness of the housing portion.

The present invention can provide a sound absorbing mat that is easy to recycle or dispose of the sound absorbing material because it does not use a toxic polymer adhesive and is not molded into a plate at high temperature and high pressure.

Since the sound absorbing mat of the present invention can control the sound absorption rate of the chaff sound absorbing layer by adjusting the thickness of the housing part or the specific gravity of the chaff, it is possible to provide a sound absorbing material capable of actively absorbing sound according to the frequency of the noise source.

The sound-absorbing mat of the present invention is environmentally friendly because it uses rice husks that are easy to supply and receive and are free of disposal as a sound absorbing material. In addition, the sound absorbing mat of the present invention has a uniform particle size and uses an elastic chaff in a three-dimensional shape, so it can be used as an active sound absorbing material as well as showing high sound absorption properties.

1 is a cross-sectional view of an active control sound absorbing mat that is an embodiment of the present invention.
2 to 5 measure the sound absorption rate according to the specific gravity and thickness of the sound absorbing layer.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art to which the present invention pertains may easily practice. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. In the drawings, parts not related to the description are omitted in order to clearly describe the present invention, and the same reference numerals are used for the same or similar elements throughout the specification. In addition, detailed descriptions of well-known technologies are omitted.

In the present specification, when a part “includes” a certain component, it means that the component may further include other components, not to exclude other components, unless otherwise stated.

1 is a cross-sectional view of an active control sound-absorbing mat that is an embodiment of the present invention, and FIGS. 2 to 5 are sound absorbing coefficients measured according to specific gravity and thickness of the sound-absorbing layer.

Referring to FIG. 1, the active control sound absorbing mat includes a housing portion 10 and a rice husk sound absorbing layer 20.

The housing portion 10 is adjustable in thickness, and the chaff is packed inside.

The housing may be a fabric or a stretchable metal mesh.

When the housing is a fabric or a metal net, the active control sound absorbing mat may further include a base plate on which the fabric housing or the metal net housing is placed and fixed, and may also include a fabric layer or a top plate covering the housing. You can.

Referring to FIG. 1, the housing part may include an upper plate 11, a lower plate 12, a stretchable metal mesh 13 positioned between them, and a fastening part 14 capable of compressing the metal mesh. . The housing part may include a sound-absorbing wood 15 between the lower plate and the metal net. The sound absorbing wood can absorb noise in a different frequency band from chaff.

On the lower plate 12, a metal mesh 13 filled with the chaff is placed, and an upper plate is placed on the metal mesh. The fastening portion 14 may be made of a bolt and a nut. One end (end) of the threaded bolt is fixed to the lower plate, and the other end (another end) penetrates over the top plate and protrudes. When the nut is inserted into the bolt and tightened, the top plate descends to compress the metal net and chaff to control the specific gravity (density) of the chaff.

In addition, even if the specific gravity of the rice husk is adjusted, the sound absorption rate can be controlled by adjusting the thickness of the entire sound absorbing layer.

The chaff absorbing layer 20 is a chaff layer filled in the housing.

The chaff sound absorbing layer 20 may include chaff of a single size or chaff of various sizes depending on the purpose of use of the soundproof mat.

Rice husk is produced as a by-product of the rice plantation in the countryside, and rice husk is a peeled shell, and because it has space inside, it has elasticity. Since the interior space is empty, it can realize a high sound insulation effect and it is easy to handle due to its light weight.

The inventors of the present invention have found that the chaff has a uniform particle size and high elasticity, so it can be used in active control sound absorbing mats like the present invention.

The sound absorption rate of the chaff sound absorbing layer may be 0.9 to 1.

The thickness of the rice husk sound absorbing layer may be 6 to 10 cm.

The chaff sound absorbing layer may have an apparent specific gravity (hereinafter, specific gravity) of 0.1 to 0.12.

 The active control sound insulation mat of the present invention can vary the sound absorption rate by controlling the density, porosity, air flow resistervity, and torsion force of the chaff sound absorbing layer according to the compression of the housing portion. .

For example, the active control sound-absorbing mat can be used as a highway soundproofing wall by adjusting the specific gravity of the sound absorbing layer to 0.1 to 0.12 and the thickness to 6 to 8 cm.

In addition, the active control sound-absorbing mat can be used as a soundproofing wall on a general road by adjusting the specific gravity of the sound absorbing layer to 0.1 to 0.12 and the thickness to 9 to 11 cm.

Since the soundproofing mat of the present invention does not mold the chaff layer at high temperature and high pressure, airflow is easily achieved through the gap between the chaff particles, so it is possible to improve the sound absorption rate by reducing the airflow resistance compared to the board using the adhesive.

In addition, the present invention can be manufactured by further assembling the back surface (back plate) and the frame on the soundproof mat to produce a soundproof wall. In this case, when a wood-based material such as plywood having a large transmission loss is used as the back surface, a soundproof wall suitable for the noise characteristics of the location where the soundproof wall is used can be manufactured.

Example

The rice husk was packed in a metal net, and then the sound absorption rate was measured according to the following. 4cm is the thickness of the metal net in the [Granul 4cm-1], [Granul 4cm-2], [Granul 4cm-3] and [Granul 4cm-4] shown in the graph, and 1, 2, 3, 4 are packing The rice husks were 0.06, 0.08, 0.1, and 0.12, respectively. In other words, rice husk 4cm-1 means that the weight of rice husk packed in a 4cm thick metal mesh is 0.06. 2 to 5, the x-axis is frequency, and the y-axis is sound absorption rate.

Fig. 2 shows the sound absorption rate of a soundproof mat having a thickness of 4 cm when the chaff (that is, the sound absorbing layer) specific gravity in the metal mesh is changed to 0.06, 0.08, 0.1 and 0.12.

Referring to FIG. 2, it can be seen that the absorption rate is about 0.8 at a specific gravity of 0.12 at about 1550 Hz, and decreases as the specific gravity decreases, so that the absorption rate at 0.08 is only about 0.6.

3 is a graph showing the sound absorbing performance of the chaff mat having a thickness of 6 cm when the specific gravity of the chaff is changed to 0.06, 0.08, 0.1 and 0.12. Referring to FIG. 3, the sound absorption rate at about 800 Hz is about 0.9 with a specific gravity of 0.1, and when the specific gravity is 0.12, the sound absorption at about 1 KHz is about 0.95, indicating a sound absorption rate close to 1. Therefore, the sound absorbing layer has a specific gravity of 0.12 and a thickness of 6 cm. The soundproof mat has a high noise level around 1 KHz when the various types of transportation run at normal speeds, especially on highways paved with asphalt. Considering this, it is possible to optimize the design as a soundproof wall of the highway.

4 is a graph showing the sound absorbing performance of the soundproof mat having a thickness of 8 cm when the specific gravity of the chaff of the sound absorbing material according to an embodiment of the present invention is changed to 0.06, 0.08, 0.1 and 0.12. 5, it can be seen that the sound absorption rate of rice husks with a specific gravity of 0.12 at about 700-800 Hz is superior to about 1. Therefore, the sound absorbing layer has a specific gravity of 0.12 and a thickness of 8 cm. The sound insulation mat has a high noise level around 800 Hz when various types of transportation run at normal speeds, especially on highways paved with concrete. Considering this, it is possible to optimize the design as a soundproofing wall for highways.

Figure 5 is a graph showing the sound absorption performance of the chaff soundproof mat having a specific gravity of 0.06, 0.08, 0.1 and 0.12, and a thickness of 10 cm according to an embodiment of the present invention. 6, when the specific gravity is 0.12, it can be seen that the sound absorption rate is about 1 at about 700 Hz, and has a sound absorption rate of 0.8 or more in the entire frequency range of the x-axis. Therefore, the chaff mat having a specific gravity of 0.12 and a thickness of 10 cm can be optimized as a soundproofing wall such as a road or bus stop near a residential area where trucks are frequently operated.

The soundproof mat according to the embodiment of the present invention can be utilized in the production of a soundproof wall and a soundproof tunnel, and it is possible to manufacture an eco-friendly soundproof wall and a soundproof tunnel.

The soundproof mat of the present invention can effectively reduce low-frequency noise such as highways by using chaff.

According to an embodiment of the present invention, taking into consideration environmental factors such as road transport means, road pavement materials (concrete, asphalt) and distance from noise sources at the locations where soundproof walls and soundproof tunnels are installed, the thickness of the chaff absorbing layer, the size of the chaff, By varying the filling pressure and density (tension of the packaging layer), a soundproof mat optimized for the installation environment can be produced.

The embodiments of the present invention have been described in detail above, but the scope of rights of the present invention is not limited to this, and various modifications and improvements made by those skilled in the art to which the present invention pertains also include the rights of the present invention. Belongs to the scope.

Claims (9)

A soundproofing wall comprising a sound absorbing mat,
The sound absorbing mat has a thickness adjustable housing portion 10 and a chaff sound absorbing layer 20 packed in the housing portion,
The housing part 10 is
It includes an upper plate 11, a lower plate 12, a stretchable metal mesh 13 positioned between them, and a fastener 14 capable of pressing the metal mesh,
The chaff sound absorbing layer 20 is a layer filled with a plurality of chaff, and the chaff has elasticity as it has a space therein,
The sound absorbing mat has an apparent specific gravity of 0.1 to 0.12, a thickness of 6 to 10 cm, and a sound absorption rate of 0.9 to 1, by adjusting the thickness of the housing portion to press the elastic chaff sound absorbing layer or to remove the pressing force. Active control sound barrier, characterized in that to control.



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