KR101897468B1 - Air transparent soundproofing device - Google Patents

Abstract

The present invention provides a ventilation type soundproofing device with a noise reduction structure capable of performing ventilation. By using one pair of easily understandable design parameters, the ventilation type soundproofing device is able to perform an identical level of soundproofing function with a general soundproofing wall in a frequency range wanted by a designer. The soundproofing device comprises: a body portion; and an insertion pipe.

Description

[0001] Air transparent soundproofing device [0002]

The present invention relates to a ventilating type sound insulating apparatus. More particularly, the present invention relates to a ventilating type sound insulation apparatus having a noise reduction structure capable of ventilation, and capable of achieving high sound insulation performance equivalent to that of a conventional general sound insulation wall.

In a region where large noise is routinely generated, such as a road or a railroad, a sound-shielding wall is installed to block noise spreading around the periphery. It is obvious that noise can be effectively absorbed by blocking the vibration of the medium because it is a vibration that propagates through a medium such as air. Such a conventional sound barrier wall is excellent in noise shielding effect, but inevitably blocks air flow, which often causes various environmental problems. On the other hand, even in the case of a window installed in a building such as a house, when the window is closed, the flow of air is blocked, so that noise can be blocked. However, when the window is opened for ventilation, . As described above, since the sound insulation structure that blocks noise by blocking the flow of the medium itself blocks the ventilation, it is disadvantageous that it is not possible to realize sound insulation and ventilation at the same time.

In order to solve this problem, Korean Patent Registration No. 1422113 ("Ventilated or waterproof type soundproof wall having a resonance chamber for a car which is superimposed around a ventilation passage or a water passage", 2013.04.26, hereinafter referred to as Prior Art 1) No. 1668676 ("Soundproof Panel with Wind Load Reducing Type and Soundproof Wall Using the Same", May 1, 2015, hereinafter referred to as Prior Art 2), the noise is reduced by using the resonance phenomenon of sound waves, Techniques. In the case of the prior art document 1, a resonance chamber for reducing the noise by combining the diffraction and resonance phenomenon of the wave was introduced. In the case of the prior art 2, a single soundproof panel having a single resonance chamber, .

However, in the case of these conventional technologies, only a measurement result of a predetermined size is presented, and it is not clear how to apply design variables when the size is changed and applied, so that it is difficult to apply it to ordinary windows and soundproof walls . In addition, the measured results show that the sound insulation performance is significantly lower than that of commonly used windows or soundproof walls.

1. Korean Patent No. 1422113 ("Ventilated or waterproofed sound barrier with resonant chambers for car superimposed around aeration or passage", 2013.04.26) 2. Korean Patent No. 1668676 ("Soundproof panel with reduced wind load and soundproof wall using it", 2015.09.14)

1. M. Garai, P. Guidorzi, JASA 108, 1054, 2000, European methodology for testing the airborne sound insulation characteristics of noise barriers in situ: Experimental verification and comparison with laboratory data

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a noise reduction structure capable of being ventilated, So as to obtain a sound insulation performance equivalent to that of a general soundproof wall in a frequency range.

According to an aspect of the present invention, there is provided a ventilating type sound insulating apparatus comprising: a body portion having an empty space formed therein and having a ventilation hole formed in a front surface and a rear surface thereof; An insertion tube (112) formed in a tubular shape and provided in each of the ventilation holes (111h), and inserted and extended into the body part (111); And a plenum chamber 110, which includes the plenum chamber 110. At this time, the ventilation sound insulating apparatus 100 may have a plurality of the plurality of the plenum chambers 110 arranged in the up-and-down direction and the left-right direction.

In addition, the ventilation-type sound insulating apparatus 100 is designed such that the shape of the plenum chamber 110 is designed so as to block noise of a predetermined target frequency band, and a resonance frequency (frequency) determined by the shape of the plenum chamber 110 wherein the resonance frequency fr is less than the target frequency band and the cutoff frequency fc is greater than the target frequency band, Can be designed.

More specifically, in the ventilating type sound insulating apparatus 100, the resonance frequency fr is determined by the following equation (1), and the cut-off frequency fc can be determined by the following equation (2).

(Formula 1)

(C: sonic velocity, S: insertion tube cross sectional area, L: insertion tube equivalent length, V: body volume)

(Second formula)

(Where, c: sound velocity, D: body diameter)

Also, the target frequency band may be determined to be an audio frequency band.

Further, the ventilation hole 111h may be formed at the center of the front surface or the rear surface of the body portion 111. [

Also, the insertion tube 112 may be provided with a single or a plurality of insertion holes 111h.

The insertion tube 112 may have a pipe shape extending vertically to the front surface or the rear surface of the body part 111 or may have a pipe shape having one end communicating with the vent hole 111h and the other end being connected to the inside of the body part 111 It may be a spiral tube shape open to the space.

The insertion tube 112 is formed in a spiral tube shape and is stacked in parallel to the front surface or the rear surface of the body portion 111. One end of the insertion tube 112 is connected to the spiral hole 111h at a position corresponding to the vent hole 111h. A panel 112a on which a hole 112s is formed and a finishing plate 112b on which a communication hole 112h is formed at a position corresponding to the other end of the helical hole 112s and which is stacked in parallel to the front surface or the rear surface of the body portion 111, (112b).

In addition, the method of designing a ventilating type sounder according to the present invention includes: a body portion 111 having a hollow space formed therein and having a ventilation hole 111h formed at the center of the front and rear surfaces; A pair of insertion tubes (112) formed in a tubular shape and provided in the respective vent holes (111h), and inserted into the body part (111); A target frequency band determining step of determining a target frequency band that is a frequency band of a noise to be cut off; Using the initial value of the shape of the plenum chamber 110 so determined that the resonance frequency fr and the cutoff frequency fc determined by the shape of the plenum chamber 110 are design variables, A design parameter calculating step of calculating the resonance frequency fr by a formula 1 and calculating the cut-off frequency fc by the following equation 2;

(Formula 1)

(C: sonic velocity, S: insertion tube cross sectional area, L: insertion tube equivalent length, V: body volume)

(Second formula)

(Where, c: sound velocity, D: body diameter)

The insertion tube cross-sectional area S, the equivalent tube insertion length L and the body volume V of the plenum chamber 110 are adjusted so that the resonance frequency fr is less than the target frequency band, Designing the shape of the plenum chamber 110 by adjusting the body portion diameter D of the plenum chamber 110 so that the frequency fc exceeds the target frequency band; . ≪ / RTI >

In this case, the planar chamber shape designing step may include the steps of: determining a body portion diameter D of the plenum chamber 110 such that the cutoff frequency fc is greater than the target frequency band; When the ventilating type sound insulating apparatus 100 has a high degree of importance in thickness designing conditions according to the degree of importance of the design condition of the ventilating type sound insulating apparatus 100, The insertion tube cross-sectional area S is determined after the insertion tube equivalent length L and the body volume V of the insertion chamber 110 are first determined and the importance of the opening area design condition of the ventilation- The insertion tube cross-sectional area S is first determined so that the resonance frequency fr is less than the target frequency band, and then the equivalent tube length L and the body volume V are determined; . ≪ / RTI >

According to the present invention, there is a great advantage in that the apparatus can be constructed using a plenum chamber in which air can be communicated, thereby achieving the effect of ventilation and noise isolation. Although there is a ventilating type sound insulation apparatus in the past, there has been a problem that the sound insulation performance is significantly lower than that of a general sound insulation wall such as a window and a sound insulation wall. However, according to the present invention, noise is equivalent to a sound insulation performance of a general sound insulation wall There is a big effect of being blocked.

Further, the present invention can design a shape using a pair of design variables that are easy to understand, so that even if the size of a region to be sounded is changed, the design can be changed easily according to the size, There is an effect to improve.

1 is a typical Helmholtz resonator.
2 is an embodiment of a plenum chamber included in the ventilating type sound insulating apparatus of the present invention.
3 is another embodiment of the insertion tube of the ventilating sound insulating apparatus of the present invention.
4 is an embodiment of the ventilating type sound insulating apparatus of the present invention.
5 is a photograph of an embodiment of a ventilating sound insulating apparatus of the present invention.
FIG. 6 is a STL (Sound Transfer Loss) graph showing design parameters of the ventilating type sound insulating apparatus of the present invention.
7 is a graph showing the results of actual sound insulation performance measurement of the ventilating type sound insulating apparatus of the present invention.

Hereinafter, a ventilating type sound insulating apparatus according to the present invention having the above-described structure will be described in detail with reference to the accompanying drawings.

Figure 1 shows a typical Helmholtz resonator. As shown in FIG. 1, the Helmholtz resonator is formed in a container shape having a relatively small diameter neck in a body in which an empty space is formed, and is a sound absorbing device. The Helmholtz resonator can be replaced by a system of mass and spring, ie the air in the neck acts as the mass and the air inside acts as a spring. When resonance occurs, the air in the neck part is severely exited, causing friction with the pipe wall, and the friction is converted into thermal energy, thereby causing sound absorption. The equation for finding the _resonant frequency at resonance in Helmholtz resonator is known as follows.

(C: speed of sound, S: neck cross section, L: neck equivalent length, V: body volume, l: neck length, r: neck radius)

The ventilating type sound insulating apparatus of the present invention is fundamentally based on the principle of the Helmholtz resonator as described above. More specifically, the ventilating type sound insulation apparatus of the present invention includes a plenum chamber in which sound absorption is performed using the principle of Helmholtz resonator. 2 shows an embodiment of the plenum chamber 110 included in the ventilating type sound insulating apparatus of the present invention. The plenum chamber 110 includes a body part 111 and an insertion tube 112, .

As shown in the drawing, the body portion 111 has a hollow space formed therein, and a ventilation hole 111h is formed on the front and rear surfaces thereof. In the case of the Helmholtz resonator, the ventilation hole 111h is formed only on one side, so that the air is in and out. However, since the ventilation hole 111h is formed on both the front and rear sides of the body part 111 of the present invention, You can escape to the other side. That is, the air can pass through the body portion 111. As shown in the drawing, the vent hole 111h is formed at the center of the front or rear surface of the body 111. However, the present invention is not limited thereto, It is also acceptable.

The insertion tube 112 is formed in a tubular shape as shown and is provided in each of the ventilation holes 111h. The insertion tube 112 may be provided with a single opening for each of the ventilation holes 111h, or a plurality of the insertion tubes 112 may be provided. 2 shows a case where the insertion tube 112 is provided with a single ventilation hole 111h. In this case, the ventilation hole 111h is formed on both the front and rear sides of the body part 111 And the insertion tube 112 are provided in a pair.

On the other hand, in the case of the Helmholtz resonator, as shown in the figure, the neck is protruded to the outside of the body, whereas the insertion tube 112 of the present invention has a shape which is inserted and extended into the body part 111 . In addition, the insertion tube 112 of the present invention may be in the shape of a pipe extending vertically to the front or rear surface of the body 111 as shown in the example of FIG. 2, but the present invention is not limited thereto.

As will be described in greater detail below, the length, diameter, etc. of the insertion tube 112 is closely related to the frequency of the noise to be intercepted. 2, the longer the length of the insertion tube 112, the greater the thickness of the plenum chamber 110 is. Therefore, the length of the insertion tube 112 is necessarily longer than the length of the insertion tube 112 ) Should be thicker than twice the length. At this time, when there is a limitation on the thickness of the region where the ventilation sound insulating apparatus 100 of the present invention including the plenum chamber 110 is installed, it may be difficult to set the frequency of the noise to be blocked as desired.

In order to solve the above-described problem, the insertion tube 112 has a spiral tube, one end of which is connected to the ventilation hole 111h and the other end of which is opened to the internal space of the body 111, Shape. Fig. 3 shows an example of the insertion tube 112 in the shape of a helical tube. More specifically, Fig. 3 (A) shows an example in which a pipe is bent in a spiral shape to form a spiral pipe shape. On the other hand, FIG. 3 (B) shows a panel 112a having a spiral hole 112s disposed at a position corresponding to the vent hole 111h at one end and a position corresponding to the other end of the spiral hole 112s And a finishing plate 112b having a communication hole 112h is sequentially laminated on the front surface or the rear surface of the body portion 111 to form a spiral tube shape.

The ventilation type sound insulating apparatus 100 of the present invention may be formed of a single single piece of the planetary chambers 110 having the above-described shape, but a plurality of the planetary chambers 110 It is most preferable that they are arranged vertically and horizontally. FIG. 4 shows an embodiment of the ventilating type sound insulating apparatus 100 of the present invention, and FIG. 5 shows a photograph of an embodiment of the ventilating type sound insulating apparatus 100 of the present invention.

As described above, the ventilating type sound insulation apparatus 100 according to the present invention is a noise reduction structure that can be ventilated. By using a pair of design variables that are easy to understand, the designer can obtain a sound insulation performance equivalent to a general sound insulation wall in a desired frequency range . This will be described in more detail as follows.

The ventilation type sound insulating apparatus 100 of the present invention is designed such that the shape of the plenum chamber 110 is designed so as to block noise of a predetermined target frequency band and a resonance frequency (fr) and cut-off frequency (fc) as design variables. In this case, the target frequency band may be determined to be an audible frequency band in consideration of a general purpose of sound insulation, and may be a commonly used standard range of 100 to 3500 Hz or 125 to 4000 Hz. Alternatively, in a region where noise of a specific frequency band is particularly generated, the target frequency band may be narrower to the corresponding frequency band so as to more effectively block the noise of the corresponding frequency band. Or the ventilated sound insulating apparatus 100 of the present invention can be applied to an area where the medium is not air such as underwater, and in this case, the target frequency band is suitably changed according to the change of the medium It may be determined differently from a general audio frequency band. Thus, the target frequency band can be appropriately changed depending on the purpose, environment, and the like.

On the other hand, in general, when the sound insulation performance is evaluated, a STL (Sound Transfer Loss) graph is used for the frequency. In other words, it is a frequency-by-frequency measurement of how much the transmission noise is reduced at a certain frequency. In general, if the transmission noise loss amount is 30 dB or more, the sound insulation performance is considered sufficient. FIG. 6 is a STL graph showing the design parameters of the ventilating type sound insulating apparatus of the present invention. In the STL graph, a pair of design variables, that is, the resonance frequency fr and the cutoff frequency fc, The lowest values are displayed. In other words, effective noise cancellation can be achieved in the frequency band between the resonance frequency fr and the cut-off frequency fc.

In the present invention, by designing the shape of the plenum chamber 110 so that the resonance frequency fr is less than the target frequency band and the cutoff frequency fc is greater than the target frequency band, Performance can be achieved and a design suitable for the size of a region where noise is to be blocked can be easily made. The resonance frequency fr and the cut-off frequency fc are determined by the following equations (1) and (2), respectively.

(Formula 1)

(C: sonic velocity, S: insertion tube cross sectional area, L: insertion tube equivalent length, V: body volume)

The first equation is similar to the above-described equation for obtaining the resonance frequency of the Helmholtz resonator, but since the plenum chamber 110 of the present invention has two insertion tubes 112 (corresponding to the neck of the Helmholtz resonator) The value is doubled. On the other hand, various cases of obtaining the equivalent length L of the insertion tube will be described as follows. 2, in the case of a pipe shape having a single perforation hole 111h and extending vertically to the front surface or the rear surface of the body portion 111, (Equivalent length of insertion tube (L) = Insertion tube length (l) + 0.1 x Insertion tube radius (r)] can be used in the same manner as in the equation for obtaining resonance frequency. However, when a plurality of the insertion tubes 112 are provided per one of the ventilation holes 111h, the insertion tube cross-sectional area S should be calculated as an effective area corresponding thereto. Also, even when the insertion tube 112 has a helical tube shape as shown in FIG. 3, the effective length, effective area, effective radius, etc. corresponding to the shape of the helical tube are calculated and applied to the above equation.

(Second formula)

(Where, c: sound velocity, D: body diameter)

The second equation is a formula for calculating the frequency at which the higher-order mode of a sound wave first occurs, and is a generally well-known formula (similar to the equation for obtaining the resonant frequency of a Helmholtz resonator). When a higher-order mode of sound waves occurs, the sound waves pass through without being blocked. That is, in order for the noise of the target frequency band to be effectively blocked, the frequency at which the higher-order mode occurs (the cut-off frequency fc) should be higher than the target frequency band.

The plenum chamber 110 constituting the ventilating type sound insulating apparatus 100 of the present invention can determine the resonance frequency fr and the cutoff frequency fc according to the shape. In other words, if the resonance frequency fr and the cut-off frequency fc are determined as desired, the shape of the plenum chamber 110 may be determined accordingly. As described above, the ventilating type sound insulating apparatus 100 of the present invention determines the resonance frequency fr and the cut-off frequency fc so as to block the noise of a desired frequency band and adjusts the shape of the plenum chamber 110 accordingly It is very easy to design in a way to determine. Also, the size of the ventilation-type sound insulating apparatus 100 is not limited to the specific size, but can be adjusted as desired.

The method for designing the ventilating type sound insulating apparatus 100 of the present invention can be summarized as including a target frequency band determination step, a design parameter calculation step, and a planar chamber shape design step. Each step will be described in more detail as follows.

In the determination of the target frequency band, as described above, the frequency band of the noise to be blocked is appropriately determined according to a desired purpose, an environment of a region where the sound insulating device is to be installed, and the like. This can be determined as the user desires, and if there are no limitations or conditions, it can be determined to be a standard range of 100 to 3500 Hz or 125 to 4000 Hz, which is generally widely used as an audio frequency band.

The initial value of the shape of the plenum chamber 110 is determined so that the resonance frequency fr and the cutoff frequency fc determined by the shape of the plenum chamber 110 are design variables, The resonance frequency fr is calculated by the first equation and the cut-off frequency fc is calculated by the second equation. The initial value of the shape of the plenum chamber 110 is literally a simple initial value and can be determined by the designer as desired.

The shape of the plenum chamber 110 is designed such that the resonance frequency fr is less than the target frequency band and the cutoff frequency fc is greater than the target frequency band. . Here, the resonance frequency fr is related to the insertion tube cross-sectional area S, the equivalent tube length L, and the body volume V, (D) of the plenum chamber (110). The insertion tube cross-sectional area S, the insertion tube equivalent length L, and the body volume V of the plenum chamber 110 are adjusted so that the resonance frequency fr is less than the target frequency band, And the body portion diameter D of the plenum chamber 110 may be adjusted so that the cut-off frequency fc is greater than the target frequency band.

As an example, the planar chamber shape designing step will be described in more detail as follows.

In the second equation, the cut-off frequency fc is related only to the body portion diameter D, so that it is relatively easy to design. Therefore, first, the body portion diameter D of the plenum chamber 110 may be determined such that the cut-off frequency fc is greater than the target frequency band.

Meanwhile, the importance of the design condition of the ventilating type sound insulating apparatus 100 may be determined depending on the size of the area where the ventilating type sound insulating apparatus 100 is installed. For example, the area of the area to be sounded is irrelevant, but it may be desired that the thickness be less than a certain level, or the area of the opening affecting the ventilation performance may have to be determined fixedly. Depending on the degree of importance of the design conditions of the ventilating sound insulating apparatus 100 determined in advance, it may be determined whether the shape parameters related to the thickness are first adjusted or the shape parameters related to the area are adjusted first. That is, when the thickness design condition of the ventilating type sound insulating apparatus 100 is high, the equivalent length L of the insertion tube of the plenum chamber 110 and the length L of the body portion of the plenum chamber 110 are set such that the resonance frequency fr is less than the target frequency band. The insertion tube cross-sectional area S can be determined after the volume V is first determined. On the other hand, when the ventilating sound insulating apparatus 100 has a high degree of importance in designing the opening area, the insertion tube cross-sectional area S is first determined so that the resonance frequency fr is less than the target frequency band, And the body volume V can be determined.

It is assumed that the above example assumes that the insertion tube 112 is in the form of a pipe extending perpendicularly to the front or rear surface of the body 111, but the present invention is not limited thereto. If it is not possible to reduce the thickness as much as desired in adjusting the thickness-related shape parameters, it is possible to change the shape of the insertion tube 112 from a pipe shape to a spiral tube shape in a proper sequence of the above processes, It is possible to carry out.

FIG. 7 shows a result of measuring the actual sound insulation performance of the ventilating type sound insulating apparatus of the present invention. In Fig. 7, Rw-30 indicates a sound insulation performance evaluation standard used in the ISO (International Organization for Standardization). Rw is calculated as the difference between the sound transmission loss and the Rw reference curve in the range of 100 to 3150 Hz of the measurement object. The sum of the differences of the two values in the frequency bands is calculated from Rw .

[Table 1]

[Table 2]

Tables 1 and 2 are presented in the references (M. Garai, P. Guidorzi, JASA 108, 1054, 2000, Experimental verification and comparison with laboratory data of insulation characteristics of noise barriers in situ: European methodology for testing Which shows the soundproof wall materials and their performance. These soundproof wall materials are widely used in the real industry. Table 1 and Table 2 show the structures and Rw values of the iron soundproof walls (MET1-7), the acrylic soundproof wall (ARC1) and the like well. Compared with these values, it can be seen that the present invention has a very good performance comparable to that of an actual industrial soundproofing wall even though it includes openings for ventilation.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. It goes without saying that various modifications can be made.

100: ventilating type sound insulating device 110: plenum chamber
111: body portion 111h: ventilation hole
112: insertion tube
112a: Panel 112s: Spiral hole
112b: Finishing plate 112h:

Claims (10)

A body portion having a hollow space formed therein and having a ventilation hole formed on a front surface and a rear surface thereof; An insertion tube formed in a tubular shape and provided in each of the ventilation holes, the insertion tube being inserted into the body part; And a plenum chamber including a plenum chamber,
Wherein the shape of the plenum chamber is designed so as to block noise of a predetermined target frequency band, and a resonance frequency and a cutoff frequency determined by the shape of the plenum chamber are designed as design variables,
The shape of the plenum chamber is designed such that the resonant frequency is less than the target frequency band and the cutoff frequency is greater than the target frequency band,
Wherein the resonant frequency is determined by the following equation (1)
Wherein the cut-off frequency is determined by the following equation (2).
(Formula 1)

(C: sonic velocity, S: insertion tube cross sectional area, L: insertion tube equivalent length, V: body volume)
(Second formula)

(Where, c: sound velocity, D: body diameter)
The ventilating type sound insulating apparatus according to claim 1,
Wherein the plurality of the plenum chambers are arranged in the up-and-down direction and the left-right direction.
delete delete 2. The method of claim 1,
And is determined to be an audible frequency band.
The air conditioner according to claim 1,
Wherein the ventilation hole is formed at the center of the front surface or the rear surface of the body portion.
The insertion tube according to claim 1,
Wherein a single or a plurality of ventilation holes are provided per one of the ventilation holes.
The insertion tube according to claim 1,
A pipe shape extending vertically to the front surface or the rear surface of the body portion,
And a spiral tube having one end connected to the vent hole and the other end opened to the internal space of the body.
9. The apparatus according to claim 8,
And is formed in a helical tube shape,
A panel having a spiral hole formed at a position corresponding to the vent hole and having one end thereof stacked in parallel on the front surface or the rear surface of the body portion,
A finishing plate which is stacked in parallel to a front surface or a rear surface of the body portion and has a communication hole at a position corresponding to the other end of the helical hole,
Wherein the ventilating-type sound insulating apparatus comprises:
A body portion having a hollow space formed therein and having a vent hole at the center of the front and rear surfaces; A pair of insertion tubes formed in a tubular shape and provided in the respective vent holes, the insertion tubes being inserted into the body part; And a plenum chamber including a plenum chamber,
Determining a target frequency band that is a frequency band of a noise to be blocked;
Using the initial value of the shape of the plenum chamber determined in advance so that the resonance frequency and the cut-off frequency determined by the shape of the plenum chamber are design variables, the resonance frequency is calculated by the following equation A design parameter calculating step of calculating the cutoff frequency according to a second equation;
(Formula 1)

(C: sonic velocity, S: insertion tube cross sectional area, L: insertion tube equivalent length, V: body volume)
(Second formula)

(Where, c: sound velocity, D: body diameter)
The insertion tube cross-sectional area, the insertion tube equivalent length, and the body volume of the plenum chamber are adjusted so that the resonance frequency is less than the target frequency band,
The diameter of the body portion of the plenum chamber is adjusted so that the cutoff frequency is greater than the target frequency band,
A planar chamber shape design step in which the shape of the plenum chamber is designed;
Wherein the first and the second ventilation holes are formed in a predetermined shape.

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