JP2019132576A - Silent ventilating structure - Google Patents

Abstract

To provide a crank box type silent ventilating structure arranged on a decorative sheet and a wall, capable of improving a sound muffling performance while maintaining a ventilation property, and having a higher sound muffling effect than an air-column resonance structure.SOLUTION: A crank box type silent ventilating structure arranged on a decorative sheet and a wall has a hollow silencer container arranged in a space between the decorative sheet and the wall, at least two opening pipe parts respectively connected to two opposed side faces of the silencer container and respectively communicated with a space in the silencer container, a sound absorbing material provided inside the silencer container, and a coating material for coating at least one part of a surface of the silencer container. The above-mentioned problem is solved by exposing the other of the surface of the sound absorbing material and constituting the exposed portion as at least one contact face contacting the space in the silencer container.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a silencer ventilation structure of a crankbox type. More specifically, the present invention relates to a crankbox type sound deadening structure provided between a decorative board and a wall and having a high sound deadening effect while maintaining air permeability.

  Conventionally, ventilation structures such as ventilation sleeves and louvers that require ventilation allow noise to pass through at the same time as air, so noise countermeasures may be required. In a conventional ventilation structure, a sound absorbing material is installed in the structure in order to obtain a sound deadening performance (see Patent Documents 1, 2, and 3).

  The technique described in Patent Document 1 is a crankbox type silencer ventilation device that ventilates inside and outside a building. This silencer ventilator is composed of a hollow silencer container with a sound absorbing material affixed to the inner surface, a resonance sound absorber having the same coaxial inner diameter at the outdoor ventilation port of the silencer container, and a silencer comprising a supply cylinder. Is done. This silencer ventilator can improve the sound insulation without increasing the air flow resistance in the room.

  The technology described in Patent Document 2 is a silencer with a louver structure in which bent-shaped air passages for ventilating inside and outside of a building are arranged in a multi-stage shape so as to reduce the sound pressure of noise sound waves passing through the air passages. is there. This silencer is provided on the surface of the blade body facing the ventilation path, the blade body formed in a bent shape that separates the adjacent ventilation paths, the silencer chamber that houses the sound absorbing material in the space inside the blade body, and And a plate-like member (curved sound wave reflection plate) for guiding noise sound waves entering from one first ventilation port of the air passage to the inside of the silencer chamber. In this louvered silencer, the length of the ventilation path can be shortened, and the ventilation path and the silencing chamber can be stacked in multiple stages over the entire wall surface, providing excellent air permeability while providing sound insulation. You can do that.

  Similarly to Patent Document 2, the technique described in Patent Document 3 is provided with a bent air passage that ventilates the inside and outside of a building in a multistage manner so as to reduce the sound pressure of noise sound waves that pass through the air passage. It is a louver structure silencer. This silencer accommodates first and second curved sound wave reflecting plates that reflect noise sound waves, and a sound absorbing material, respectively, and introduces sound waves reflected by the first and second sound wave reflecting plates. Thus, the first and second silencing chambers for reducing the sound pressure are provided, and the first silencing chamber and the second silencing chamber are continuously arranged in the air passage. With this louvered structure silencer as well as the silencer disclosed in Patent Document 2, the length of the ventilation path can be shortened, and the ventilation path and the silencing chamber can be stacked in multiple stages over the entire wall surface. It is said that excellent air permeability can be obtained while providing sound insulation.

JP 2013-164229 A JP 2008-144996 A JP 2008-1222023 A

By the way, in a ventilation structure, it is effective to install a sound absorbing material in order to obtain a sound deadening performance, but if a lot of sound absorbing materials are installed in order to improve the sound deadening performance and obtain a high sound deadening performance, the air permeability is impaired. There was a problem of being.
Moreover, in the technique of patent document 1, the noise reduction apparatus attached to the outdoor side ventilation port of a noise reduction container other than the hollow noise reduction container which affixed the sound-absorbing material on the inner surface is required. For this reason, since the space between the decorative board and the outer peripheral wall needs a space for attaching at least the resonance sound absorbing material of the sound reduction device in addition to the sound deadening container, the space between the decorative board and the outer peripheral wall is narrow There was a problem that sufficient air permeability could not be secured. Further, in the case of resonant sound absorption by the resonant sound absorbing material, there is a problem that the sound deadening performance is not sufficient.

In addition, the technologies disclosed in Patent Documents 2 and 3 are based on a gallery structure, and the air passages between the sound deadening chambers (blade bodies) are stacked in multiple stages between the decorative plate and the outer peripheral wall (concrete wall). There is a problem that it is difficult to dispose them due to space constraints. In addition, the techniques disclosed in Patent Documents 2 and 3 have a problem that the cost is high because a curved acoustic wave reflection plate or a punching plate is used.
Therefore, in the crankbox type silencer ventilation structure installed between the decorative plate and the outer peripheral wall (concrete wall), in order to achieve both high noise reduction performance and air permeability, while using the sound absorbing material of the same volume, It was required to absorb sound with high efficiency.

  The present invention solves the above-mentioned problems and problems of the prior art, and in the silencer ventilation structure disposed on the decorative board and the wall, the silencer performance can be improved while maintaining the air permeability. It is an object of the present invention to provide a crankbox type silencing ventilation structure that has a higher silencing effect than a column resonance structure.

  In order to achieve the above object, the silencing ventilation structure of the first aspect of the present invention is a crankbox type silencing ventilation structure provided so as to communicate a decorative plate and a wall separating two spaces. A hollow muffler disposed in a space between the plate and the wall; at least two open pipes connected to two opposing side surfaces of the muffler; respectively, and communicating with the space in the muffler; A sound-absorbing material provided inside, and a covering material that covers a part of the surface of the sound-absorbing material, the opening tube portion on one side of the sound-absorbing container is arranged to communicate with the decorative plate, The opening tube part on the other side of the sound deadening container is arranged to communicate with the wall, and the opening pipe part on one side and the opening pipe part on the other side are arranged at different positions in the longitudinal direction of the sound deadening container. And the covering material exposes the other part of the surface of the sound absorbing material. Constitutes at least one contact surface in contact with the space silencer vessel.

Here, the sound absorbing material is affixed to the inner surface of the sound deadening container excluding the opening tube portion, and the covering material is preferably a sound insulating material.
The at least one contact surface has a resonance mode wavelength λ, a length in the longitudinal direction of the silencer L, a positive integer n, and a resonance mode wavelength λn λn = 2L / n, And when the sound wave of λn falls in the audible range, it exists within the range of λn / 8 from the antinode of the sound pressure of the sound wave of any wavelength λn, or λn / It is preferable that it exists in the range of 8.
The positive integer n is preferably 3 or less.

Moreover, it is preferable that at least one contact surface occupies an area of 1% to 50% with respect to the entire area of the surface of the sound absorbing material.
Moreover, it is preferable that the sound absorbing material is attached to an area of 50% or more with respect to the entire area of the inner surface of the sound deadening container excluding the opening tube.
The volume of the sound absorbing material is preferably 1% to 50% of the volume of the sound deadening container.
Moreover, it is preferable that the sound absorbing material is affixed to the entire inner surface of the silencer container excluding the opening tube.
In addition, the tubular body has at least one tubular body having an opening that opens into a space in the sound deadening container, and the inside of the tubular body is filled with a sound absorbing material, and the opening of the tubular body is a surface of the sound absorbing material. It is preferable that a part of the exposed part is exposed and the exposed part is configured as a contact surface that comes into contact with the space in the sound deadening container.

  In order to achieve the above object, the silencing ventilation structure of the second aspect of the present invention is a crankbox type silencing ventilation structure provided so as to communicate a decorative plate and a wall separating two spaces. A hollow muffler disposed in a space between the plate and the wall; at least two open pipes connected to two opposing side surfaces of the muffler; respectively, and communicating with the space in the muffler; And an acoustic absorption material provided inside the tubular body, and the opening tube portion on one side of the sound deadening container communicates the decorative plate. The opening tube portion on the other side surface of the sound deadening container is disposed so as to communicate with the wall, and the opening tube portion on one side surface and the opening tube portion on the other side surface are in the longitudinal direction of the sound deadening container. Arranged in different positions, the opening of the tubular body is It exposes a portion of the surface of the sound absorbing material, constituting the exposed portion as a contact surface in contact with the space silencer vessel.

Here, the contact surface has a resonance mode wavelength λ, a length in the longitudinal direction of the silencer L, a positive integer n, a resonance mode wavelength λn λn = 2L / n, and λn When the sound wave falls within the audible range, it exists within the range of λn / 8 from the antinode of the sound pressure of the sound wave of any wavelength λn, or λn / 8 from the longitudinal end of the sound deadening container. It is preferable to exist within the range.
The positive integer n is preferably 3 or less.
Moreover, it is preferable that a contact surface occupies an area of 1%-50% with respect to the total area of the inner surface of the sound deadening container excluding the opening tube portion.
The volume of the sound absorbing material is preferably 1% to 50% of the volume of the sound deadening container.
Moreover, it is preferable that a tubular body is arrange | positioned in a silencer container.
Moreover, it is preferable that the tubular body is disposed outside the sound deadening container, and the opening of the tubular body is open to at least one side surface of the sound deadening container.
Moreover, it is preferable that the tubular body is embedded in at least one of the wall and the decorative board in a state of protruding to at least one side of the wall and the decorative board.
The tubular body is preferably made of a sound insulating material.

The length in the longitudinal direction of the inner space of the tubular body from the center of the opening on the one end side of the tubular body to the end on the other end side of the tubular body is Ld, and the width of the opening in the longitudinal direction of the sound deadening container is When it is assumed that Lo and the wavelength of the resonance mode frequency in which the resonance mode of the silencer is 1, the length in the longitudinal direction satisfies the following formulas (1) and (2). preferable.
Ld> Lo (1)
0.011 × λ <Ld <0.25 × λ (2)
Further, in the cross section parallel to the longitudinal direction of the sound deadening container, when the width of the internal space in the direction orthogonal to the length of the internal space of the tubular body is Lw, the width Lw of the internal space is expressed by the following formula (3 ) Is preferably satisfied.
0.001 × λ <Lw <0.061 × λ (3)

The area of the opening of the tubular body is S1, the total surface area of the inner surface of the inner space of the tubular body is Sd, and the tube from the center of the opening on one end side of the tubular body to the end on the other end side of the tubular body is formed. When the length in the longitudinal direction of the internal space of the body is Ld and the wavelength of the resonance mode frequency in which the order of the resonance mode of the silencer is 1 is λ, the ratio S1 / Sd of the area S1 to the area Sd and the length The direction length Ld preferably satisfies the following formulas (4) and (2).
0 <S1 / Sd <40% (4)
0.011 × λ <Ld <0.25 × λ (2)

  According to the present invention, in the silencer ventilator arranged on the decorative board and the wall, the silencer performance can be enhanced while maintaining the air permeability, and the silencer effect is higher than that of the conventional sound absorbing material and the air column resonance structure. A crankbox-type silenced ventilation structure can be provided.

It is typical sectional drawing which shows an example of the silencing ventilation structure which concerns on one Embodiment of this invention. It is the schematic diagram showing the vibration mode of the silencing container of the silencing ventilation structure shown in FIG. 1, and the graph shown typically. It is typical sectional drawing which shows an example of the silencing ventilation structure which concerns on other embodiment of this invention. It is typical sectional drawing which shows another example of the silencing ventilation structure which concerns on other embodiment of this invention. It is typical sectional drawing which shows another example of the silencing ventilation structure which concerns on other embodiment of this invention. It is a graph which shows typically a plurality of resonance modes of a silencer container of a silencer ventilation structure shown in FIG. It is typical sectional drawing which shows another example of the silencing ventilation structure which concerns on other embodiment of this invention. It is typical sectional drawing which shows the silencing ventilation structure of a reference example. It is typical sectional drawing which shows the noise reduction ventilation structure of the comparative example 1. It is explanatory drawing which shows the basic calculation model used in the Example of this invention. It is a graph which shows the relationship between the frequency of Example 1, reference example, and comparative example 1 of this invention, and the average value of the square of the absolute value of sound pressure. It is typical sectional drawing which shows another example of the silencing ventilation structure which concerns on other embodiment of this invention. It is typical sectional drawing which shows the silence ventilation structure of the comparative example 2-1. It is typical sectional drawing which shows the silence ventilation structure of the comparative example 2-2. It is a graph which shows the relationship of the average value of the square of the frequency of Example 2, reference example, comparative example 2-1, and comparative example 2-2 of this invention, and the absolute value of sound pressure. It is typical sectional drawing which shows the silence ventilation structure which concerns on Example 3 of this invention. It is a graph which shows the relationship between the frequency of Example 3-1 to 3-5 of this invention, and the average value of the square of the absolute value of a sound pressure of a reference example. It is a schematic diagram which shows an example of the sound pressure distribution of the silencing container of the silencing ventilation structure shown in FIG. It is a schematic diagram which shows another example of the sound pressure distribution of the silencing container of the silencing ventilation structure shown in FIG. It is a graph which shows the relationship between the distance between the edge part of the silencer container of Examples 3-1 to 3-5 of this invention, and a tubular body opening part center, and the average value of the square of the absolute value of sound pressure. It is typical sectional drawing which shows another example of the silencing ventilation structure which concerns on other embodiment of this invention. It is a schematic diagram of the acoustic characteristic measurement system which implements the acoustic tube 4 microphone measurement method.

Below, the silencing ventilation structure which concerns on this invention is demonstrated in detail.
The description of the constituent elements described below is made based on typical embodiments of the present invention, but the present invention is not limited to such embodiments.
In the present specification, a numerical range expressed using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.
The silencing ventilation structure of the first embodiment of the present invention is a crankbox type silencing ventilation structure provided so as to communicate a decorative plate and a wall separating two spaces, and is provided between the decorative plate and the wall. A hollow sound-absorbing container disposed in the space, at least two open pipes connected to two opposing side surfaces of the sound-absorbing container, respectively, and communicating with the space in the sound-absorbing container, and a sound absorbing device provided in the sound-absorbing container And a covering material that covers a part of the surface of the sound absorbing material, and the opening tube portion on one side surface of the sound deadening container is disposed so as to communicate with the decorative plate, The opening tube portion is disposed so as to communicate with the wall, the opening tube portion on one side surface and the opening tube portion on the other side surface are disposed at different positions in the longitudinal direction of the sound deadening container, and the covering material is configured to absorb sound. Expose the other part of the surface of the material, Characterized in that it constitutes at least one contact surface touching.

  In addition, the noise reduction ventilation structure of the second embodiment of the present invention is a crankbox type noise reduction ventilation structure provided so as to communicate a decorative board and a wall separating two spaces. A hollow silencer disposed in a space between the two, and at least two opening pipe portions respectively connected to two opposing side surfaces of the silencer container and communicating with the space in the silencer container, and opened in the space in the silencer container At least one tubular body having an opening to be sounded, and a sound absorbing material provided inside the tubular body, and the opening tube on one side surface of the sound deadening container is arranged to communicate with the decorative plate, The opening tube part on the other side of the sound deadening container is arranged to communicate with the wall, and the opening pipe part on one side and the opening pipe part on the other side are arranged at different positions in the longitudinal direction of the sound deadening container. The opening of the tubular body is formed on the surface of the sound absorbing material. Parts exposing the, characterized in that it constitutes a contact surface for contact with the space silencer vessel.

The present invention is a crankbox-type silenced ventilation structure disposed between a decorative board and a wall, covering a part of the sound-absorbing material inside the crankbox-type structure, or including a sound-absorbing material inside, By connecting the tubular body having the opening to the inside of the crankbox structure, the sound deadening performance can be enhanced while maintaining the air permeability.
Although the conventional sound-absorbing material is not sufficient in reducing the low-frequency sound, the low-frequency sound is superior to the conventional one in the present invention.
The present invention can enhance the sound deadening performance by covering a part of the sound absorbing material or by directing the opening of the tubular body provided with the sound absorbing material inside the sound deadening container. In the present invention, the sound absorbing material is covered with a sound insulating material and an opening is provided in a part thereof, thereby increasing the particle velocity of sound flowing into the sound absorbing material, thereby increasing the sound absorption to the sound absorbing material. Based on the principle.
Thus, the present invention can realize a crankbox type silencing ventilation structure having a higher silencing effect than the conventional sound absorbing material and the air column resonance structure.
As a result, the silencing ventilation structure of the present invention can be applied to equipment and building materials such as equipment ducts, ventilation sleeves, and residential ventilation systems.

(Silenced ventilation structure)
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the following, a silencing ventilation structure according to the present invention will be described in detail with reference to preferred embodiments shown in the accompanying drawings.
(Silent ventilation structure of the first embodiment)
FIG. 1 is a cross-sectional view schematically showing an example of a silencing ventilation structure according to the first embodiment of the present invention.
A silencing ventilation structure 10 according to the first embodiment of the present invention shown in FIG. 1 is a crankbox type silencing ventilation structure, and is a rectangular parallelepiped silencing container 12 and a sound absorbing material 14 attached to the inner surface of the silencing container 12. A covering material 16 that covers a part of the surface of the sound absorbing material 14, a first opening pipe portion 18 connected to one side (indoor side) of the sound deadening container 12, and the other side (outdoor side) of the sound deadening container 12. And a second opening tube portion 20 connected to the side surface.
The silencer ventilation structure 10 includes a decorative board 26 and a wall (for example, an outer peripheral wall, a concrete wall) 28 that separate two spaces, an internal space (indoor space) 22 and an external space (outdoor space) 24 of a building such as a house. Are provided to communicate with each other. That is, the silencing ventilation structure 10 is provided so as to communicate the two spaces 22 and 24.

(Silence container)
The silencing container 12 is a hollow container having a vertically long rectangular parallelepiped shape, and obtains a silencing effect by the sound absorbing material 14 attached to the inner surface. The muffler container 12 is disposed in a space 30 between the decorative plate 26 and the wall 28.
Below the sound deadening container 12, a first opening 13 a that opens to a side surface (indoor side) on the decorative board 26 side is provided. The first opening pipe portion 18 on the indoor side is connected to the first opening 13a.
Above the sound deadening container 12, a second opening 13 b that opens to a side surface (on the outdoor side) on the wall 28 side is provided. The second opening pipe portion 20 on the outdoor side is connected to the second opening 13b.
That is, the first opening 13a where the indoor side sound is likely to be emitted and the second opening 13b where the outdoor side sound is likely to enter are not on the same axis line, and the positions thereof are shifted up and down (that is, the longitudinal direction of the silencer container). In different positions).
In the example shown in FIG. 1, the first opening 13a is provided below and the second opening 13b is provided above. Conversely, the first opening 13a may be provided above and the second opening 13b provided below. good.
In the example shown in FIG. 1, one first opening 13 a is provided on the indoor side surface of the muffler container 12, but two or more may be provided. Similarly to the first opening 13a, one second opening 13b is provided on the side surface on the outdoor side, but two or more may be provided.

In the example shown in FIG. 1, the muffler container 12 is a hollow container having a vertically long rectangular parallelepiped shape, but the present invention is not limited to this. The sound deadening container 12 can be disposed in the space 30 between the decorative plate 26 and the wall 28 and may be a hollow container having any shape as long as it is vertically long. For example, a hollow container having a circular, elliptical, or polygonal cross section can be used.
The material of the sound deadening container 12 is used for a ventilator or the like, and is not particularly limited as long as it does not amplify incident sound by vibrations or propagate to the outside, and any material can be used. good. For example, metal materials such as aluminum, titanium, magnesium, tungsten, iron, steel, chromium, chromium molybdenum, nichrome molybdenum, and alloys thereof, acrylic resin, polymethyl methacrylate, polycarbonate, polyamideid, polyarylate, polyetherimide, Resin materials such as polyacetal, polyether ether ketone, polyphenylene sulfide, polysulfone, polyethylene terephthalate, polybutylene terephthalate, polyimide, triacetyl cellulose, carbon fiber reinforced plastics (CFRP), carbon fiber, and glass fiber Examples thereof include reinforced plastics (GFRP: Glass Fiber Reinforced Plastics), concrete, mortar, and the like as building wall materials.
As the silencing container 12, a conventionally known silencing container can be used as long as it is a silencing container used in a crankbox type silencing ventilation structure.

(Sound absorbing material)
The sound absorbing material 14 absorbs sound by converting sound energy of sound passing through the sound absorbing material 14 into heat energy.
The sound absorbing material 14 is affixed to the entire inner surface of the sound deadening container 12 except for the first opening 13a and the second opening 13b.
There is no limitation in particular as the sound-absorbing material 14, A conventionally well-known sound-absorbing material can be utilized suitably. For example, foamed materials such as urethane foam, flexible urethane foam, wood, ceramic particle sintered material, phenol foam, and materials containing minute air; glass wool, rock wool, microfiber (such as 3M Synthalate), floor mat, Carpets, meltblown nonwoven fabrics, metal nonwoven fabrics, polyester resin nonwoven fabrics, fibers such as metal wool, felt, insulation board, and glass nonwoven fabric, and nonwoven fabric materials; wood wool cement board; nanofiber materials such as silica nanofibers; gypsum board; Various known sound absorbing materials can be used.

  In the example shown in FIG. 1, the sound absorbing material 14 is affixed to the entire inner surface of the silencer container 12 excluding the first opening 13a and the second opening 13b, but the present invention is not limited to this, and the sound absorbing material. The sound absorbing material 14 is pasted in an area of 50% or more with respect to the entire area of the inner surface of the sound deadening container 12 excluding the first opening 13a and the second opening 13b. It is preferable. Here, the area of the inner surface of the muffler 12 may be calculated by measuring the dimensions of each part of the muffler 12. Since the sound absorbing material 14 is difficult to calculate strictly, for example, when the surface is uneven, the area of the sound absorbing material 14 is calculated by obtaining the area of the inner surface of the uncoated sound absorbing container 12 and subtracting it from the total surface area. do it.

(Coating material)
The covering material 16 covers a part of the surface of the sound absorbing material 14. As a result, the covering material 16 exposes the other part (other than the covered part) of the surface of the sound absorbing material 14 and configures the exposed part as a contact surface 32 that comes into contact with the space in the sound deadening container 12. is there.
In the example shown in FIG. 1, the contact surface 32 includes a contact surface 32 a on the surface of the sound absorbing material 14 on the upper portion attached to the ceiling surface of the sound absorbing container 12, and a lower portion attached to the bottom surface of the sound absorbing container 12. It is preferable that the contact surface 32b on the surface of the sound absorbing material 14 and the two contact surfaces 32c and 32c at the center portion of the surface of the sound absorbing material 14 attached to two opposing side surfaces of the sound deadening container 12 are formed.
Therefore, the covering material 16 covers the surface of the sound absorbing material 14 except for the four contact surfaces 32a, 32b, 32c, and 32c.
Here, the contact surface 32 preferably occupies an area of 1% to 50% with respect to the entire area of the surface of the sound absorbing material 14. The reason is that if the contact surface 32 has an area within this range, the noise reduction effect can be improved compared to the conventional case where the entire surface area of the sound absorbing material 14 is not covered by the covering material 16 at all. .
By covering a part of the sound absorbing material 14, the sound pressure in the vicinity of the contact surface of the sound absorbing material 14 can be increased, and the high sound pressure region and the low region within the sound absorbing material 14 can be provided. The sound pressure difference can be made remarkable as compared with the case where the sound absorbing material 14 is not covered. For example, the sound pressure is low in a portion on the back side from the contact surface 32 in the covering region. When a region with a high sound pressure and a region with a low sound pressure are formed, the particle velocity increases in the region between them. When the particle velocity increases in the resistor (sound absorbing material 14), the loss increases. For this reason, the silencing effect can be enhanced.
In the present invention, since the sound absorbing material 14 is difficult to calculate strictly, for example, when the surface is uneven, the area of the contact surface 32 of the sound absorbing material 14 is defined as the area of the opening of the covering material 16. To do. Here, the area of the opening portion of the covering material 16 is defined as an area of a plane approximated by a plane including the opening frame of the covering material 16 or a smooth curved surface.

By the way, as shown in FIG. 2, when the sound that has entered the silencing container 12 propagates in the silencing container 12, it resonates at a predetermined resonance (natural) frequency and becomes a standing wave. The sound of the resonance frequency in this resonance mode is a sound that easily goes out of the muffler container 12. In this resonance mode (secondary), as shown in FIG. 2, the sound pressure antinode AN of the standing wave in the muffler 12 is provided above and below the muffler 12 and at the center. Reference symbol N represents a sound pressure node.
In the present invention, with respect to the node N and the belly AN of the sound pressure, the sound pressure is measured while tracing the measurement microphone at 1 cm intervals in the muffler container 12, and the position where the sound pressure becomes the maximum is measured. AN and the position where it becomes the minimum are defined as the node N of the sound pressure.
For this reason, by providing the contact surfaces 32 (32a, 32b, 32c, and 32c) on the top, bottom, and center of the sound deadening container 12, sound absorption is performed at the portion that becomes the antinode AN of the sound pressure of the resonance frequency of this resonance mode. The contact surface 32 where the surface of the material 14 is exposed can be arranged to efficiently absorb sound, and a high silencing effect can be obtained.

  In the 4-microphone method, as in the acoustic characteristic measurement system 80 shown in FIG. 22, a material 90 made of a sound insulating material used as the covering material 16 is disposed in an aluminum acoustic tube (tubing body 82), and an acoustic tube ( The acoustic characteristics are measured by the transfer function method using the four microphones 86 arranged on the tube body 82).

This method follows “ASTM E2611-09: Standard Test Method for Measurement of Normal Incidence Sound Transmission of Acoustical Materials Based on the Transfer Matrix Method”. As an acoustic tube, for example, an aluminum tube 82 is used on the basis of the same measurement principle as that of WinZac manufactured by Nippon Acoustic Engineering Co., Ltd. (For WinZac, a web document “https://www.noe.co. jp / en / download / pdf / winzac.pdf "). A cylindrical box 88 that houses a speaker 86 is disposed below the tube body 82, and the tube body 82 is placed on the top surface of the box 88. A sound with a predetermined sound pressure is output from the speaker 86 and measured by the four microphones 84. With this method, sound transmission loss can be measured in a wide spectral band.
Specifically, using this technique, the material 90 having a sound insulating property is arranged as shown in FIG. 22 so as to block the acoustic tube (tube body 82) having a diameter of 2 cm without gap, and measurement is performed. The transmittance T is obtained, and transmission loss TL = 10 * log ₁₀ (1 / T) can be obtained. As described above, a material having a transmission loss TL of 5 dB or more over 200 Hz to 8000 Hz is defined as a sound insulating material.

  The covering material 16 may be a sound insulating material, that is, a material that does not pass sound, for example, aluminum, titanium, magnesium, tungsten, iron, steel, chrome, having a thickness that does not vibrate against sound, Metal materials such as chromium molybdenum, nichrome molybdenum, alloys thereof, acrylic resin, polymethyl methacrylate, polycarbonate, polyamideide, polyarylate, polyetherimide, polyacetal, polyetheretherketone, polyphenylene sulfide, polysulfone, polyethylene terephthalate, Resin materials such as polybutylene terephthalate, polyimide, triacetyl cellulose, carbon fiber reinforced plastics (CFRP), carbon fibers, and glass fiber reinforced plastics ( FRP: Glass Fiber Reinforced Plastics), wall material similar to concrete buildings, mention may be made of a mortar or the like.

In the present invention, the contact surface 32 (32a, 32b, 32c, and 32c) preferably has a center position at which the wavelength of the sound at the resonance frequency of the resonance mode of the silencer 12 is λ and the length of the silencer 12 in the longitudinal direction. When the length is L, the positive integer (order) is n, the wavelength λn of the resonance mode is λn = 2L / n, and the sound wave of λn falls in the audible range, at least one sound wave of the wavelength λn It is preferable to exist within the range of λn / 8 from the antinode AN of the sound pressure within 12. The reason for this is that the resonance mode wavelength λn satisfies λn = 2L / n and the sound having a wavelength corresponding to the audible range becomes a sound that is easy to come out, so it becomes a sound that must be extinguished. This is because 32 is closer to the sound pressure antinode AN, and the sound deadening effect is higher.
The contact surface 32 (32a, 32b) is preferably centered at a longitudinal position in the silencer 12 when the resonance mode wavelength λn is λn = 2L / n and the sound wave of λn falls in the audible range. It is preferable that it exists in the range of λn / 8 from the end in the direction (from both ends). The reason is that the silencing effect is higher when the contact surface 32 is closer to the longitudinal ends (in the both ends) of the silencer 12 where the sound pressure antinode AN is located.
Here, the positive integer n is preferably 3 or less. That is, the resonance mode wavelength λn satisfies λn = 2L / n, and among the sounds corresponding to the wavelength corresponding to the audible range, the resonance mode order is relatively low, such as n = 1,2,3. This is because the sound of the frequency tends to come out, and the sound of the low frequency needs to be turned off. Moreover, it is because the low frequency sound has a problem that it is difficult to eliminate it with the sound absorbing material 14 alone.

(Opening tube)
The two first and second opening pipe portions 18 and 20 are respectively connected to two opposing side surfaces of the sound deadening container 12 and communicate with a space in the sound deadening container 12.
That is, the first opening pipe portion 18 is connected to the first opening 13 a on the side surface on the indoor side of the sound deadening container 12 and communicates with the space in the sound deadening container 12. The first opening tube portion 18 is disposed so as to communicate with the decorative plate 26. In other words, the first opening tube portion 18 may be disposed so as to penetrate at least a part of the decorative plate 26, or may be disposed so as to be connected to a through opening provided in the decorative plate 26.
The second opening tube portion 20 is connected to the second opening 13 b on the side surface on the outdoor side of the sound deadening container 12 and communicates with the space in the sound deadening container 12. Further, the second opening pipe portion 20 is disposed so as to communicate with the wall 28. That is, the second opening pipe portion 20 may be disposed so as to penetrate at least a part of the wall 28 or may be disposed so as to be connected to a through opening provided in the wall 28.
Since the 1st opening pipe part 18 and the 2nd opening pipe part 20 are connected to the 1st opening 13a and the 2nd opening 13b which are respectively arrange | positioned in the position where the longitudinal direction of the silencing container 12 differs, the silencing container 12 It will be arranged at a different position in the longitudinal direction. Here, when at least one of the first opening 13a and the second opening 13b is a plurality of openings, at least one of the first opening tube portion 18 and the second opening tube portion 20 is accordingly Needless to say, a plurality of openings are connected to the plurality of openings.

(Silent ventilation structure of the second embodiment)
FIG. 3 is a cross-sectional view schematically showing an example of a silencing ventilation structure according to the second embodiment of the present invention.
The silencing and ventilation structure 40 of the second embodiment of the present invention shown in FIG. 3 has the silencing and ventilation structure 10 of the first embodiment of the present invention shown in FIG. 1 and the sound absorbing material 14 attached to the inner surface of the silencing container 12. Since it has the same configuration except that there is no point, the same components are denoted by the same reference numerals, and detailed description thereof is omitted.
The silencing ventilation structure 40 is a crankbox-type silencing ventilation structure, and is a rectangular parallelepiped silencing container 12, a tubular body 42 having an opening 44 opening in a space in the silencing container 12, and an inside of the tubular body 42. The sound absorbing material 14 provided, the first opening pipe part 18 connected to one side (indoor side) of the noise reduction container 12, and the second opening pipe connected to the other side (outdoor side) of the noise reduction container 12 Part 20.
The silencer ventilation structure 40 is similar to the silencer ventilation structure 10, and the decorative plate 26 and the wall (for example, the interior space (inside the house) 22 and the outside space (outside the house) 22 of the building such as a house are separated. An outer peripheral wall and a concrete wall) 28 are provided so as to communicate with each other. That is, the silencing ventilation structure 10 is provided so as to communicate the two spaces 22 and 24.

(Tubular body)
In the example illustrated in FIG. 3, the tubular body 42 is disposed so as to be in contact with the bottom surface in the sound deadening container 12 and the side surface on the outdoor side. The tubular body 42 has an opening 44 that opens into a space in the sound deadening container 12.
The tubular body 42 is provided with the sound absorbing material 14 filled therein.
The opening 44 is located on the bottom surface side in the sound deadening container 12. The opening 44 exposes a part of the surface of the sound absorbing material 14 from the tubular body 42, and the exposed portion of the sound absorbing material 14 is configured as a contact surface 32 that comes into contact with the space in the sound deadening container 12.
By the way, it can be said that the side surface of the tubular body 42 in contact with the space in the sound deadening container 12 constitutes the covering material 16. Here, the tubular body 42 is preferably made of a sound insulating material.
Here, the shape of the tubular body 42 is not particularly limited as long as the tubular body 42 can be disposed at a predetermined position in the sound deadening container 12, has the opening 44, and can be filled with the sound absorbing material 14. Examples of the shape of the tubular body 42 include a rectangular column tube shape, a cylindrical column tube shape, and a polygonal tube shape.
The material of the tubular body 42 is not particularly limited as long as the sound absorbing material 14 can be filled. The material of the tubular body 42 is preferably a material that does not transmit sound, for example, aluminum, titanium, magnesium, tungsten, iron, steel, chromium, chrome molybdenum, and nichrome molybdenum having a thickness that does not vibrate against sound. , Metal materials such as these alloys, acrylic resin, polymethyl methacrylate, polycarbonate, polyamideide, polyarylate, polyetherimide, polyacetal, polyetheretherketone, polyphenylene sulfide, polysulfone, polyethylene terephthalate, polybutylene terephthalate, Resin materials such as polyimide and triacetylcellulose, carbon fiber reinforced plastics (CFRP), carbon fibers, and glass fiber reinforced plastics (GFRP: Glass Fi) ber Reinforced Plastics), concrete, mortar, etc. similar to building wall materials.

In addition, since the position of the longitudinal direction of the opening part 44 of the tubular body 42 and its center position are the same as the position of the longitudinal direction of the contact surface 32, and its center position, the muffler ventilation structure 40 of 2nd Embodiment of this invention. As in the silencing ventilation structure 10 of the first embodiment of the present invention, when the resonance mode wavelength λn is λn = 2L / n and the sound wave of λn falls within the audible range, It is preferable that it exists in the range of λn / 8 from the pressure belly AN, or in the range of λn / 8 from the end in the longitudinal direction in the sound deadening container 12. The reason is that when the opening 44 (that is, the contact surface 32) of the tubular body 42 is closer to the sound pressure antinode AN, the sound deadening effect is higher, and when the sound pressure is separated from the sound pressure antinode AN, the sound deadening effect becomes weaker. .
The positive integer n is preferably 3 or less. The reason for this is that a relatively low frequency sound of 3 or less having a low resonance mode order tends to come out, and it is necessary to actively eliminate the sound.
In the example shown in FIG. 3, one tubular body 42 is disposed in the corner on the side of the wall 28 and on the bottom surface side in the silencer container 12, but the position of the opening 44 (contact surface 32) of the tubular body 42 is silenced. One or more tubular bodies 42 may be placed on the side of the decorative plate 26, on the wall 28, provided that they are within a range of λn / 8 from the longitudinal pressure AN in the container 12 or the longitudinal end of the sound deadening container 12. You may arrange | position in any position including the edge part by the side, the ceiling side, or the bottom face side.
Moreover, it is preferable that the area of a contact surface and the volume of a sound-absorbing material are prescribed | regulated similarly to the silencing ventilation structure 10 of 1st Embodiment of this invention.

In the silencing ventilation structure 40 shown in FIG. 3, the tubular body 42 is disposed in the silencing container 12, but this embodiment is not limited thereto, and the tubular body 42 is similar to the silencing ventilation structure 40 </ b> A shown in FIG. 4. (42a, 42b) may be arranged outside the muffler container 12.
In the silencing ventilation structure 40A, the tubular body 42 (42a, 42b) is arranged outside the silencing container 12 so that the longitudinal direction of the silencing container 12 and the longitudinal direction of the tubular body 42 (42a, 42b) are aligned. It is buried in the wall 28 in a state of protruding toward the side 28.
The opening 44 of the tubular body 42 (42a, 42b) is open on the side surface of the sound deadening container 12 on the wall 28 side. The surface of the sound absorbing material 14 in the tubular body 42 (42 a, 42 b) forms the contact surface 32 at the opening 44.
In the silencing ventilation structure 40A shown in FIG. 4, the opening 44 of the tubular body 42a is in the vicinity of the end in the longitudinal direction in the silencing container 12 (within λ / 8 from the end), and the opening of the tubular body 42b. 44 is in the center of the sound deadening container 12 (within the range of λ / 8 from the sound pressure antinode AN). The reason is that when the opening 44 (that is, the contact surface 32) of the tubular body 42 is closer to the sound pressure antinode AN, the sound deadening effect is higher, and when the sound pressure is separated from the sound pressure antinode AN, the sound deadening effect becomes weaker. .
However, the present invention is not limited to the above-described configuration, and the position of the opening 44 (contact surface 32) of the tubular body 42 is the sound pressure antinode AN in the sound deadening container 12, or the longitudinal end in the sound deadening container 12. To one or more tubular bodies 42 at any position including the center in the longitudinal direction, the end on the ceiling side, the end on the bottom side, or the like in the sound deadening container 12. You may embed and arrange in either the board 26 and / or the wall 28.

For example, as in the silencing ventilation structure 40B shown in FIG. 5, one opening 44 of the tubular body 42a is positioned within a range of λ / 8 from the end on the bottom surface side in the longitudinal direction in the silencing container 12. The tubular body 42 a is embedded in the wall 28, and the opening 44 of the tubular body 42 c is positioned at the longitudinal center in the sound deadening container 12 (within the range of λ / 8 from the sound pressure antinode AN). The tubular body 42c may be embedded in the decorative board 26 with both longitudinal directions aligned.
Also in the silencer ventilation structure 40B, the tubular body 42 (42a, 42c) is filled with the sound absorbing material 14, and the surface of the sound absorbing material 14 in the opening 44 constitutes the contact surface 32.
In the silencing ventilation structure 40B shown in FIG. 5, a standing wave having a resonance mode order n of 2 (n = 2) is described in the silencing container 12 along the longitudinal direction. It is shown that the end portion on the ceiling side, the center portion, and the end portion on the bottom side are antinodes of sound pressure.

FIG. 6 shows a plurality of resonance modes in the silencing container 12 of the silencing ventilation structure 40B shown in FIG.
When the order n of the resonance mode is 1 (n = 1), the end on the ceiling side in the longitudinal direction and the end on the bottom side in the sound deadening container 12 are the antinodes AN of the sound pressure. It is shown that the center in the longitudinal direction is a node N between the sound pressure antinode AN and the antinode AN.
When the order n of the resonance mode is 2 (n = 2), as shown in FIG. 5, the end on the ceiling side, the center, and the end on the bottom side in the longitudinal direction in the sound deadening container 12 are the sound pressure. It is shown that it is a node AN of the sound pressure, and a node N is located between the sound pressure belly AN and the stomach AN.
When the order n of the resonance mode is 3 (n = 3), when the length in the longitudinal direction in the sound deadening container 12 is L, the end on the ceiling side in the lengthwise direction in the sound deadening container 12, and L from this end. / 3 position, 2L / 3 position, and the bottom side end are shown to be the sound pressure antinode AN, and the middle of the sound pressure antinode AN and antinode AN is the node N It is shown.
The silencing ventilation structure 40B shown in FIG. 5 can absorb sound efficiently even when the resonance mode order n is 1 (n = 1) and 2 (n = 2), and the resonance mode order n is 2 (n = 2). It can be seen that the sound can be absorbed most efficiently in the case of.
As described in detail above, the conventional silencing ventilation structure using the sound absorbing material does not have a sufficient effect of reducing the low frequency sound, whereas the silencing ventilation structure of the present invention using the sound absorbing material reduces the low frequency sound. It can be seen that the effect is superior to the conventional one.

Further, as in the silencing ventilation structure 40C shown in FIG. 7, the tubular body 46 (46a, 46b) is arranged outside the silencing container 12 so that the longitudinal direction thereof is orthogonal to the longitudinal direction of the silencing container 12, and the side branch It is good as a type. At this time, although not shown, the tubular body 46 a is buried in the wall 28 in a state of projecting toward the wall 28 so as to be orthogonal to the wall 28 at the end on the bottom surface side in the sound deadening container 12. Although not shown, the tubular body 46b is buried in the decorative plate 26 in a state of projecting toward the decorative plate 26 so as to be orthogonal to the decorative plate 26 at the ceiling side end in the sound deadening container 12. Yes.
The opening 48 of the tubular body 46 (46a, 46b) is opened on the side wall of the sound deadening container 12 and the decorative plate 26 side. The surface of the sound absorbing material 14 in the tubular body 46 (46a, 46b) constitutes the contact surface 32 at the opening 48.
In the silencing ventilation structure 40C shown in FIG. 7, the opening 48 (contact surface 32) of the tubular body 46a is in the vicinity of the end on the bottom side in the longitudinal direction in the silencing container 12 (within a range of λ / 8 from the end). The opening 48 (contact surface 32) of the tubular body 46b is in the vicinity of the end on the ceiling side in the longitudinal direction in the sound deadening container 12 (within λ / 8 from the end). That is, it is preferable that the opening 48 (contact surface 32) of the tubular body 46 (46a, 46b) is within a range of λ / 8 from the sound pressure antinode AN. The reason is that the sound deadening effect is higher when the opening 48 (contact surface 32) of the tubular body 46 (46a, 46b) is closer to the sound pressure antinode AN. The positive integer n is preferably 3 or less. The reason for this is that a relatively low frequency sound of 3 or less having a low resonance mode order tends to come out, and it is necessary to actively eliminate the sound.
However, the present invention is not limited to the above-described configuration, and the position of the opening 48 (contact surface 32) of the tubular body 46 is from the sound pressure antinode AN in the sound deadening container 12 or the longitudinal end in the sound deadening container 12. If it is within the range of λ / 8, one or three or more tubular bodies 46 are placed at any position including the end on the ceiling side in the longitudinal direction or the end on the bottom side in the sound deadening container 12. You may embed and arrange | position in the state which protruded in the inside of the decorative board 26 and / or the wall 28. FIG.

In the second embodiment of the present invention, for example, as shown in FIGS. 5 and 7, the longitudinal direction of the internal space of the tubular body 42 of the silencing ventilation structure 40B and the tubular body 46 of the silencing ventilation structure 40C is used. If the length is Ld and the width of the opening 44 of the tubular body 42 and the width of the opening 48 (contact surface 32) of the tubular body 46 in the longitudinal direction of the sound deadening container 12 is Lo, the internal space of the tubular bodies 42 and 46 Is longer than the width Lo of the openings 44 and 48 (contact surface 32).
That is, the length Ld preferably satisfies the following formula (1).
Ld> Lo (1)

Here, the length in the longitudinal direction of the internal space of the tubular bodies 42 and 46 can also be referred to as the length of the sound wave in the internal space of the tubular bodies 42 and 46, and can be obtained by simulation. it can.
In the example shown in FIG. 5, the inner space of the tubular body 42 extends in the longitudinal direction (and therefore the traveling direction of the sound wave in the muffler container 12), so the traveling direction of the sound wave in the inner space is It is the longitudinal direction of the internal space of the tubular body 42 (that is, the longitudinal direction of the sound deadening container 12, and thus the vertical direction in the figure). Therefore, the length Ld is a distance from the center position of the opening 44 (contact surface 32) on one end side (upper side in the drawing) of the tubular body 42 in the longitudinal direction of the internal space of the tubular body 42. It is the length to the end (end surface of the internal space). When the length in the longitudinal direction of the internal space of the tubular body 42 differs depending on the position, the length Ld is an average value of the lengths at the respective positions.
When the width of the opening 44 (contact surface 32) varies depending on the position, the width Lo of the opening 44 (contact surface 32) is an average value of the width at each position.

In the example shown in FIG. 7, the internal space of the tubular body 46 protrudes in a direction orthogonal to the longitudinal direction of the sound deadening container 12, and therefore the traveling direction of the sound wave in the internal space is the protruding direction (left and right in the figure). Direction). Accordingly, the length Ld is the length from the opening 48 (contact surface 32) in the protruding direction to the other end surface (the right end surface or the left end surface in the drawing) of the internal space. When the length in the longitudinal direction of the internal space of the tubular body 46 varies depending on the position, the length Ld is an average value of the depth at each position.
When the width of the opening 48 (contact surface 32) varies depending on the position, the width Lo of the opening 48 (contact surface 32) is an average value of the width at each position.

In addition, the sound wave at the resonance frequency of the resonance mode having the resonance mode order of 1 (n = 1) (that is, the resonance frequency of the first resonance (n = 1)) of the silencer container 12 of the silencer ventilation structure 40B and 40C. Assuming that the wavelength is λ, the length Ld in the longitudinal direction of the internal space of the tubular bodies 42 and 46 satisfies 0.011 × λ <Ld <0.25 × λ.
That is, it is preferable that the length Ld also satisfies the following formula (2).
0.011 × λ <Ld <0.25 × λ (2)
As can be seen from the above equation (2), the length Ld is smaller than λ / 4, and the tubular bodies 42 and 46 are not silenced by resonance.
The length Ld preferably satisfies 0.016 × λ <Ld <0.25 × λ, and more preferably satisfies 0.021 × λ <Ld <0.25 × λ.

When the sound of the lowest resonance frequency (n = 1) of the sound deadening container 12 is silenced using a resonance-type tubular body, the length of at least 1/4 of the wavelength λ of the resonance frequency is required. Will increase in size. Therefore, there is a problem that it is difficult to achieve both high air permeability and soundproof performance.
Further, the resonance type tubular body selectively silences sound of a specific frequency (frequency band). For this reason, a design that matches the resonance frequency of the sound deadening container 12 is required, and there is a problem that versatility is low.
In addition, the resonance of the sound deadening container 12 occurs at a plurality of frequencies, but the resonance type tubular body silences a sound of a specific frequency. For this reason, the resonance sound to be silenced has only one frequency, and the frequency band in which the resonance-type tubular body silences is narrow, so that there is a problem that resonance sounds of other frequencies cannot be silenced.

In contrast, in the present embodiment, the lengths Ld in the longitudinal direction of the internal spaces in the tubular bodies 42 and 46 are the openings 44 and 48 (contact surfaces) in the traveling direction of the sound traveling in the silencer 12. 32), the length Ld in the longitudinal direction of the internal space is given by the above formula (1) where λ is the wavelength of the sound wave at the resonance frequency of the first resonance (n = 1) of the muffler vessel 12. The tubular bodies 42 and 46 satisfying (2) and (2) are connected to the sound field space of the first resonance of the sound deadening container 12 and arranged.
The tubular bodies 42 and 46 have sound energy due to the viscosity of the fluid in the vicinity of the wall surfaces of the tubular bodies 42 and 46, the irregularities (surface roughness) of the wall surfaces, and the sound absorbing material 14 disposed in the tubular bodies 42 and 46. The sound is converted into heat energy. The fluid viscosity in the vicinity of the wall surface, the unevenness (surface roughness) of the wall surface, and the sound absorbing material 14 disposed in the tubular bodies 42 and 46 can be said to be an energy conversion mechanism.

Here, since the width Lo of the openings 44 and 48 of the tubular bodies 42 and 46 is smaller than the length Ld in the longitudinal direction of the internal space of the tubular bodies 42 and 46, the sound waves in the sound deadening container 12 are generated. When flowing into the tubular body 46, the moving speed of gas (air) molecules increases while maintaining the sound pressure. The conversion efficiency from sound energy to heat energy by the above-described conversion mechanism depends on the sound pressure and the moving speed of gas molecules. For this reason, the moving speed of the gas molecules is increased while maintaining the sound pressure, so that the conversion efficiency from the sound energy to the heat energy by the above-described conversion mechanism is increased.
Since the principle of silencing does not depend on the wavelength of the sound wave, the longitudinal length Ld of the inner space of the tubular bodies 42 and 46 is smaller than ¼ of the wavelength λ at the resonance frequency of the first resonance of the silencing container 12. However, high soundproof performance can be expressed. Therefore, the tubular bodies 42 and 46 can be miniaturized, and high soundproof performance can be obtained while maintaining the air permeability of the sound deadening container 12.
In addition, since the principle of silencing by the tubular bodies 42 and 46 does not depend on the wavelength of the sound wave, even if the length and shape of the silencing container 12 are different, the soundproofing performance can be expressed, and it is adapted to the silencing container 12. Design is unnecessary and versatility is high.
Further, since the principle of silencing by the tubular bodies 42 and 46 does not depend on the wavelength of the sound wave, it is possible to silence the sound in a wide frequency band.

Further, as described above, from the viewpoint of soundproof performance and air permeability, the length Ld in the longitudinal direction of the inner space of the tubular bodies 42 and 46 is the above formula (2) (that is, 0.011 × λ <Ld < 0.25 × λ), more preferably 0.016 × λ <Ld <0.25 × λ, and 0.021 × λ <Ld <0.25 × λ. Is more preferable.
When the width of the internal space in the direction perpendicular to the length of the internal space of the tubular bodies 42 and 46 in the cross section parallel to the sound traveling direction in the sound deadening container 12 is Lw, this internal space The width Lw preferably satisfies the following formula (3).
0.001 × λ <Lw <0.061 × λ (3)
The width Lw of the internal space of the tubular bodies 42 and 46 more preferably satisfies 0.001 × λ <Lw <0.051 × λ, and 0.001 × λ <Lw <0.041 × λ. It is more preferable to satisfy. In FIG. 7, the width Lw of the internal space of the tubular body 46 is the length in the left-right direction in the figure, and coincides with the width Lo of the opening 48 (contact surface 32).

Further, in the present embodiment, the ratio S1 / Sd of the area S1 of the openings 44 and 48 to the surface area Sd of the inner wall of the inner space of the tubular bodies 42 and 46 is set to 0 <S1 / Sd <40%. The ratio of the area of the surface on which the sound wave is incident to the surface area of the conversion mechanism such as the sound absorbing material 14 is reduced, and the gas molecule corresponding to the sound wave flowing into the conversion mechanism such as the sound absorbing material 14 while maintaining the high sound pressure P is maintained. The moving speed can be increased to improve the soundproofing performance.
From the viewpoint of increasing the moving speed of the gas molecules, the area S1 (ratio S1 / Sd) of the openings 44 and 48 is preferably as small as possible. However, if the area S1 of the openings 44 and 48 is too small, the sound wave enters the internal space. Since it becomes difficult to flow in, the soundproofing performance is lowered. From the above viewpoint, the area S1 of the openings 44 and 48 with respect to the surface area Sd of the inner wall of the internal space is preferably 0.1% <S1 / Sd <40%.
That is, it is preferable that the ratio S1 / Sd of the area S1 with respect to the area Sd satisfies the following formula (4).
0 <S1 / Sd <40% (4)
The ratio S1 / Sd is more preferably 0.3% <S1 / Sd <35%, and more preferably 0.5% <S1 / Sd <30%.
The surface area Sd of the inner wall of the internal space is measured with a resolution of 1 mm. That is, when it has a fine structure such as unevenness of less than 1 mm, the surface area Sd may be obtained by averaging this.

The silencing ventilation structure of the present invention will be specifically described based on examples.
Materials, dimensions, amounts used, ratios, processing contents, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the following examples.

(Reference example)
First, the crankbox-type silenced ventilation structure 50 of the reference example shown in FIG. 8 with no sound absorbing material attached thereto was produced as a two-dimensional simulation structure. As shown in FIG. 8, the sound deadening container 12 is composed of a plate material made of an ideal rigid body that can completely ignore the thickness, and has a longitudinal direction (longitudinal direction) length of 70 cm and a width direction (thickness). It was a vertically long rectangular shape with a length of 10 cm.
The left side surface of the muffler container 12 shown in FIG. 1 has a first opening 13a having a width of 10 cm centered on a point on the short-side center line of the muffler container 12 and 20 cm above the end on the bottom surface side in the longitudinal direction. Was opened. Connected to the first opening 13a was a first opening pipe portion 18 made of an ideal rigid body that completely reflects sound and has a width of 10 cm, a length of 5 cm, and a thickness that can be ignored.
Further, on the right side surface of the muffler container 12 shown in FIG. 1, a second 10 cm diameter centered on a center line in the short direction of the muffler container 12 and 20 cm below the end on the ceiling side in the longitudinal direction. The opening 13b was opened. The second opening 13b was connected to a second opening tube portion 20 made of an ideal rigid body that completely reflects sound and has an inner diameter of 10 cm, a length of 5 cm, and a thickness that can be ignored.

(Comparative Example 1)
Next, except for the first opening 13a and the second opening 13b, the flow resistance 20000 [Pa · S / m of thickness 20 mm is formed on the entire inner surface of the silencer 12 of the silencer ventilation structure 50 of the reference example shown in FIG. ² ] was affixed with the sound absorbing material 14 made of glass wool, and the crankbox-type silenced ventilation structure 52 of Comparative Example 1 shown in FIG. 9 was produced as a two-dimensional simulation structure.

Example 1
Next, the thickness of a part of the surface of the sound absorbing material 14 affixed to the entire inner surface of the sound deadening container 12 of the sound deadening ventilation structure 52 of Comparative Example 1 shown in FIG. A crankbox-type silenced ventilation structure 10 according to Example 1 of the present invention shown in FIG. 1 was produced as a two-dimensional simulation structure.
The covering material 16 was coated on the four side surfaces (excluding the ceiling surface and the bottom surface) of the silencer container 12 of the silencer ventilation structure 10 shown in FIG. 1 by 4 cm vertically from the center in the longitudinal direction, excluding a total of 8 cm.
As a result, the contact surface 32a that comes into contact with the space of the sound deadening container 12 at the longitudinal ceiling side end of the sound deadening container 12 of the sound deadening ventilation structure 10 shown in FIG. 1 is the surface of the sound absorbing material 14 in the width direction 6 cm. . Moreover, the contact surface 32b which contacts the space of the sound deadening container 12 in the edge part of the bottom face side of the longitudinal direction of the sound deadening container 12 was the surface of the sound absorbing material 14 of 6 cm in the width direction.
Moreover, the contact surface 32c which contacts the space of the sound deadening container 12 in the center on the ceiling side in the longitudinal direction of the sound deadening container 12 was the surface of the sound absorbing material 14 having two lengthwise directions of 8 cm.

Finite element method calculation software using the basic two-dimensional calculation model shown in FIG. 10 for the silencer ventilation structure 10 of Example 1, the silencer ventilation structure 50 of the reference example, and the silencer ventilation structure 52 of the comparative example 1 thus manufactured. Two-dimensional simulation calculation was performed by a finite element method using an acoustic module of COMSOL MultiPhysics ver. 5.3 (COMSOL).
Using such a two-dimensional simulation model, as shown in FIG. 10, sound waves were incident from the outside of the hemispherical surface (radius 1 m) of one (left side) space partitioned by a wall. The sound wave was made to enter the silencing container 12 through the first opening pipe portion 18 of the silencing ventilation structure 10. Next, the sound wave incident in the muffler vessel 12 was emitted from the second opening tube portion 20 to the other (right side) space. As a result, a sound wave reaching the hemispherical surface (radius 1 m) of the right space was detected.
Thus, the sound pressure p _i measured m points in each position of the hemispherical surface of the right side of the space (i), 2 square of the absolute value of the sound pressure p _i | p _i | ² of the mean asp the formula ( Calculated according to 5). m is the number of measurement points.

Since the sound pressure p is given as a function of the position on the semicircular arc (l), the square of the absolute value of the sound pressure | p | ² is integrated along the semicircular arc (l), and the following formula ( A square line integral value isp of the absolute value of the sound pressure represented by 6) may be obtained.
The absolute value of the sound pressure represented by the following formula (7) is obtained by dividing the square integral of the square value isp of the absolute value of the sound pressure thus obtained by the length L (= πr) of the semicircular arc having the radius r. The square value | p | ² may be calculated as an average value asp.

asp = isp / (πr / 2) = 2 × isp / (πr) (7)

FIG. 11 shows the line integral value asp of the square of the absolute value of the sound pressure with respect to the 1/1 octave band frequency in Example 1, Reference Example, and Comparative Example 1 thus obtained.
As is clear from FIG. 11, in Example 1 from 125 Hz to 1000 Hz, the square line integral value asp of the absolute value of the sound pressure is lower than that of the reference example and the comparative example 1, and the incident sound can be reduced. You can see that the sound is muted. In particular, it can be seen that the peak in the vicinity of 250 Hz is sufficiently lower in Example 1 than in Reference Example and Comparative Example 1, and the incident sound can be reduced. From these results, it can be said that the effectiveness of the present invention was shown.

(Example 2)
Next, the vicinity of the longitudinal end portion of the right side surface of the silencer container 12 of the silencer ventilation structure 50 of the reference example shown in FIG. 8 is opened, and the opening 44 is opened in the space of the silencer container 12. The tubular body 42d filled with the material 14 was attached, and the crankbox type silencing ventilation structure 40D of Example 2 shown in FIG. 12 was produced as a two-dimensional simulation structure. The tubular body 42d is made of a plate material made of an ideal rigid body that can completely ignore sound and has a thickness of 150 mm in the longitudinal direction and a vertically long rectangle having a length of 20 mm in the width direction (thickness direction). It was a shape. The sound absorbing material 14 is made of glass wool having a flow resistance of 20000 [Pa · S / m ² ], and is completely filled in the tubular body 42d, and is a vertically long rectangle having a length of 150 mm in the longitudinal direction and a thickness of 20 mm in the width direction. It was a shape.
As shown in FIG. 12, the tubular body 42 d was attached at a position pushed upward by 10 mm from the end of the bottom surface in the longitudinal direction of the sound deadening container 12. The center position of the opening 44 of the tubular body 42d was located 20 mm above the end of the bottom surface of the sound deadening container 12 in the longitudinal direction. The opening 44 of the tubular body 42d was 20 mm wide in the longitudinal direction.

(Comparative Example 2-1)
A crankbox type silencing ventilation structure 54 of Comparative Example 2-1 shown in FIG. 13 was produced as a two-dimensional simulation structure. The silencing ventilation structure 54 shown in FIG. 13 is the silencing ventilation structure 40D of the second embodiment shown in FIG. 12 except that the sound absorbing material 14 in the tubular body 42d is removed and the air column resonance tube 56 having an opening 58 is obtained. I was able to. Therefore, the dimensions of the air column resonance tube 56 and the opening 58, and the arrangement positions of the air column resonance tube 56 and the opening 58 are respectively the tubular body 42d and the silencer ventilation structure 40D of Example 2 shown in FIG. The dimensions of the opening 44 and the arrangement positions of the tubular body 42d and the opening 44 were the same.

(Comparative Example 2-2)
A crankbox type silencing ventilation structure 60 of Comparative Example 2-2 shown in FIG. 14 was produced as a two-dimensional simulation structure. The silencing ventilation structure 60 shown in FIG. 14 is similar to the silencing ventilation structure 40D of the second embodiment shown in FIG. 12, and the opening 44 of the tubular body 42d is widened, and the entire surface of the tubular body 42d on the silencing container 12 side is defined as the opening 64. The sound absorbing material 14 having a thickness of 20 mm was stuck in the recess 62 without any gap. Therefore, the size of the recess 62 was equal to the size of the sound absorbing material 14, and was a vertically long rectangular shape having a length of 150 mm in the longitudinal direction and a depth of 20 mm in the width direction (thickness direction). The dimension of the opening 64 was also 150 mm in the longitudinal direction. The sound absorbing material 14 was made of glass wool having a flow resistance of 20000 [Pa · S / m ² ], and the size of the sound absorbing material 14 was equal to the size of the recess 62. The entire surface of the sound absorbing material 14 was a contact surface 66 that was in contact with the space of the sound deadening container 12. The dimension of the contact surface 66 was equal to the dimension of the opening 64.

For the silenced ventilation structure 40D of Example 2 produced in this way, the silenced ventilation structure 54 of Comparative Example 2-1, and the silenced ventilation structure 60 of Comparative Example 2-2, using the basic two-dimensional calculation model shown in FIG. It performs two-dimensional simulation calculation by a finite element method using an acoustic module FEM calculation software COMSOL MultiPhysics ver.5.3 (COMSOL Inc.), the square of the absolute value of the sound pressure at each position | average ^{2 |} p The mean value asp of the square of the absolute value of the sound pressure represented by the above formula (1) was obtained.
The average value asp of the square of the absolute value of the sound pressure with respect to the frequency in Example 2, Comparative Example 2-1, and Comparative Example 2-2 obtained in this manner is shown in FIG.

As is clear from FIG. 15, the peak in the vicinity of 300 Hz is most reduced in Example 2 compared to Comparative Example 2-1 and Comparative Example 2-2.
Next, the peak in the vicinity of 515 Hz is clearly reduced in Example 2 as compared with Comparative Example 2-1. Moreover, with respect to Comparative Example 2-2, the peak is merely shifted (split) and cannot be said to be reduced.
Therefore, as an effect, it can be said that Example 2 corresponding to the second embodiment of the present invention has the highest silencing effect.
For the peak near 750 Hz, Example 2 is aligned with Comparative Example 2-1, and the silencing effect is high.
As described above, since all of the three peaks of n = 1, 2, and 3 have the highest overall silencing effect in Example 2, it can be said that the effectiveness of the present invention has been shown.

(Examples 3-1 to 3-5)
The crankbox type silencing ventilation structure 40D of Examples 3-1 to 3-5 shown in FIG. 16 was produced as a two-dimensional simulation structure. In the silencer ventilation structure 40D shown in FIG. 16, the center position of the opening 44 of the tubular body 42d in the crankbox type silencer ventilation structure 40D of the second embodiment shown in FIG. However, it was different in that it was located xmm above.
Therefore, Example 3-1 where x = 20 mm was the same as the muffler ventilation structure 40D of Example 2 shown in FIG.
Next, in Example 3-2, x = 80 mm. In Example 3-3, x = 140 mm. In Example 3-2, x = 200 mm. In Example 3-3, x = 300 mm.

For the silenced ventilation structure 40D of Examples 3-1 to 3-5 produced in this way, using the basic two-dimensional calculation model shown in FIG. 10, the finite element method calculation software COMSOL MultiPhysics ver. 5.3 (COMSOL) is used. A two-dimensional simulation calculation by a finite element method using an acoustic module is performed, and the square of the absolute value of the sound pressure at each position | p | ² is averaged, and the absolute value of the sound pressure represented by the above formula (1) is calculated. The mean value asp of the square was determined.
The average value asp of the square of the absolute value of the sound pressure with respect to the frequencies of Examples 3-1 to 3-5 obtained in this way and the reference example is shown in FIG.
Further, FIG. 18 shows the sound pressure distribution (sound pressure level (dB): log 10 (| p |)) of sound having a frequency of 300 Hz in a predetermined space and in the silencing ventilation structure 40D. In addition, FIG. 19 shows the sound pressure distribution (sound pressure level (dB): log10 (| p |)) of sound having a frequency of 515 Hz in a predetermined space and in the silencer ventilation structure 40D.
From FIG. 18, in the case of a sound of 300 Hz, when the longitudinal center of the silencer 12 is set to 0, the end of the longitudinal ceiling (+0.35 m) of the silencer 12 and the bottom of the silencer 12 in the longitudinal direction It can be seen that at two positions at the end (−0.35 m), there is a sound pressure antinode AN. On the other hand, with the sound at 515 Hz, when the longitudinal center of the silencer 12 is 0, the longitudinal center of the silencer 12 (0 m), the end of the ceiling of the silencer 12 in the longitudinal direction (+0.35 m), In addition, it can be seen that sound pressure antinodes AN are found at three positions (−0.35 m) at the end (−0.35 m) of the bottom surface of the sound deadening container 12 in the longitudinal direction.

Further, the sound pressures of Examples 3-1 to 3-5 with respect to the distance between the end of the bottom surface in the longitudinal direction of the muffler container 12 of Examples 3-1 to 3-5 and the center of the opening 44 of the tubular body 42d. FIG. 20 shows the maximum values of the peak values near 300 Hz and 515 Hz of the line integral value asp of the square of the absolute value.
In FIG. 20, when the end of the bottom surface in the longitudinal direction of the sound deadening container 12 is 0 mm, the range of 0 mm to 143 mm corresponds to the range of λ / 8 from the belly AN of the sound pressure of 300 Hz. If it is within this range, it can be said that the silencing effect in the sound of 300 Hz is high.
On the other hand, in FIG. 20, when the end of the bottom surface in the longitudinal direction of the sound deadening container 12 is 0 mm, the ranges of 0 mm to 83 mm and 267 mm to 400 mm correspond to the range of λ / 8 from the belly AN of the sound pressure of 515 Hz. To do. If it is within these ranges, it can be said that the silencing effect in the sound of 515 Hz is high.
From FIG. 17 to FIG. 20, the silencing effect in the vicinity of 300 Hz is as the distance from the end of the bottom surface in the longitudinal direction of the silencing container 12 increases from Example 3-1 to Example 3-5. The sound pressure on the indoor space side increases as the distance from the belly of the pressure increases. That is, the silencing effect is reduced. From this, it can be seen that a higher effect is obtained when the position of the opening 44 of the tubular body 42d (= the contact surface 32 which is the surface of the sound absorbing material 14) is closer to the antinode AN of the sound pressure.
Similarly, the peak of the transmitted sound pressure near 515 Hz is low when the position of the opening of the tubular body 42d (= the contact surface 32, which is the surface of the sound absorbing material) is close to the antinode AN of the sound pressure. That is, it can be seen that a high silencing effect is obtained.
Therefore, it can be said that the effectiveness of the present invention was shown.
The effect of this invention is clear from the above Examples 1, 2, and 3-1 to 3-5.

  Although the silencing ventilation structure of the present invention has been described in detail with reference to various embodiments and examples, the present invention is not limited to these embodiments and examples and does not depart from the gist of the present invention. Of course, various improvements or changes may be made.

For example, as shown in FIG. 21, two continuous tubular bodies 42 b (42) arranged outside the sound deadening container 12 may be arranged apart from the decorative board 26 without being embedded in the decorative board 26. Further, the two continuous tubular bodies 42 c (42) arranged outside the sound deadening container 12 may be arranged so as to contact the wall 28 without being embedded in the wall 28. That is, the one or more tubular bodies 42 may be arranged so as to be separated from the decorative plate 26 or the wall 28, or in contact with the decorative plate 26 or the wall 28 without being embedded in the decorative plate 26 or the wall 28. good. Therefore, the muffler container 12 may be disposed away from at least one of the decorative plate 26 and the wall 28.
Further, as described above, the first opening tube portion 18 may be arranged so as to be connected to the through opening 68 provided in the decorative plate 26. Further, the second opening pipe portion 20 may be disposed in a through opening 70 provided in the wall 28 with a part thereof penetrating the wall 28.
Furthermore, a plurality of sound absorbing materials may be stacked as the sound absorbing material 14 filled in the tubular body 42. The plurality of sound absorbing materials may be a laminate of a plurality of one type of sound absorbing materials, may be a laminate of a plurality of types of sound absorbing materials, or may be a mixture of both. good.

10, 40, 40A, 40B. 40C, 40D, 50, 52, 54, 60 Silent ventilation structure 12 Silent container 13a First opening 13b Second opening 14 Sound absorbing material 16 Covering material 18 First opening pipe part 20 Second opening pipe part 22 Internal space (indoor space)
24 External space (outdoor space)
26 Decorative plate 28 Wall (outer wall, concrete wall)
30 Space 32, 32a, 32b, 32c, 66 Contact surface 42, 42a, 42b, 42c, 42d, 46, 46a, 46b Tubular body 44, 48, 58, 64 Opening 56 Air column resonance tube 62 Recess 68, 70 Through Opening 80 Acoustic characteristic measurement system 82 Tube 84 Microphone 86 Speaker 88 Box 90 Material of sound insulation material AN Sound pressure antinode N Sound pressure node asp Average value of sound pressure squared value isp Sound pressure Line integral value of square of absolute value n Resonance mode order (positive integer)

Claims (20)

It is a crankbox type silencer ventilation structure provided so as to communicate the decorative plate and the wall separating the two spaces,
A hollow silencer container disposed in a space between the decorative plate and the wall;
At least two open pipe portions respectively connected to two opposing side surfaces of the muffler container, each communicating with a space in the muffler container;
A sound-absorbing material provided inside the muffler container;
A covering material covering a part of the surface of the sound absorbing material,
The opening tube portion on one side surface of the sound deadening container is disposed so as to communicate with the decorative plate,
The opening tube portion on the other side surface of the sound deadening container is disposed so as to communicate with the wall,
The opening tube portion on the one side surface and the opening tube portion on the other side surface are arranged at different positions in the longitudinal direction of the sound deadening container,
The silencer ventilation structure in which the covering material exposes another part of the surface of the sound absorbing material and configures the exposed portion as at least one contact surface that comes into contact with the space in the silencer container. The sound absorbing material is affixed to the inner surface of the muffler container excluding the opening tube portion,
The silencing ventilation structure according to claim 1, wherein the covering material is a sound insulating material.   The at least one contact surface has a resonance mode wavelength λ, a length in the longitudinal direction of the silencer L, a positive integer n, and a resonance mode wavelength λn λn = 2L / n. The sound-absorbing ventilation structure according to claim 1, wherein when the sound wave of λn falls within the audible range, the sound-absorbing ventilation structure exists within a range of λn / 8 from the antinode of the sound pressure of the sound wave of any wavelength λn. The at least one contact surface has a resonance mode wavelength λ, a length in the longitudinal direction of the silencer L, a positive integer n, and a resonance mode wavelength λn λn = 2L / n. And when the sound wave of λn falls within the audible range,
The silencing ventilation structure according to claim 1 or 2, wherein the silencing ventilation structure exists within a range of λn / 8 from an end in a longitudinal direction in the silencing container.   The silencing ventilation structure according to claim 4, wherein the positive integer n is 3 or less.   The silencing ventilation structure according to any one of claims 1 to 5, wherein the at least one contact surface occupies an area of 1% to 50% with respect to a total area of the surface of the sound absorbing material.   The silencer ventilation structure according to any one of claims 1 to 6, wherein the sound absorbing material is attached to an area of 50% or more with respect to the entire area of the inner surface of the silencer container excluding the opening pipe portion. .   The silencer ventilation structure according to any one of claims 1 to 7, wherein a volume of the sound absorbing material is 1% to 50% of a volume of the silencer container.   The sound-absorbing structure according to any one of claims 1 to 8, wherein the sound-absorbing material is attached to the entire inner surface of the sound-absorbing container excluding the opening tube portion. Furthermore, it has at least one tubular body having an opening that opens into a space in the silencing container on at least one side surface of the silencing container,
The inside of the tubular body is filled with the sound absorbing material,
The said opening part of the said tubular body exposes a part of surface of the said sound-absorbing material, and comprises any exposed part as said at least 1 contact surface which contacts the space in the said sound-absorbing container. The silencing ventilation structure according to claim 1. It is a crankbox type silencer ventilation structure provided so as to communicate the decorative plate and the wall separating the two spaces,
A hollow silencer container disposed in a space between the decorative plate and the wall;
At least two open pipe portions respectively connected to two opposing side surfaces of the muffler container, each communicating with a space in the muffler container;
At least one tubular body having an opening that opens into a space in the muffler container;
A sound absorbing material provided inside the tubular body,
The opening tube portion on one side surface of the sound deadening container is disposed so as to communicate with the decorative plate,
The opening tube portion on the other side surface of the sound deadening container is disposed so as to communicate with the wall,
The opening tube portion on the one side surface and the opening tube portion on the other side surface are arranged at different positions in the longitudinal direction of the sound deadening container,
The silencer ventilation structure in which the opening of the tubular body exposes a part of the surface of the sound absorbing material and configures the exposed portion as a contact surface that comes into contact with the space in the silencer container.   The contact surface has a resonance mode wavelength λ, a length in the longitudinal direction of the silencer L, a positive integer n, a resonance mode wavelength λn λn = 2L / n, and λn 12. The muffler ventilation structure according to claim 11, wherein when the sound wave falls within the audible range, the sound wave is present within a range of λn / 8 from the antinode of the sound pressure of the sound wave of any wavelength λn. The contact surface has a resonance mode wavelength λ, a length in the longitudinal direction of the silencer L, a positive integer n, a resonance mode wavelength λn λn = 2L / n, and λn When the sound wave falls within the audible range,
The silencing ventilation structure according to claim 11, wherein the silencing ventilation structure exists within a range of λn / 8 from an end in a longitudinal direction in the silencing container.   The silencing ventilation structure according to claim 13, wherein the positive integer n is 3 or less.   The silencing ventilation structure according to any one of claims 11 to 14, wherein the contact surface occupies an area of 1% to 50% with respect to a total area of an inner surface of the silencing container excluding the opening pipe portion.   The sound-absorbing structure according to any one of claims 11 to 15, wherein a volume of the sound-absorbing material is 1% to 50% of a volume of the sound-absorbing container.   The silencer ventilation structure according to any one of claims 10 to 16, wherein the tubular body is disposed in the silencer container. The tubular body is disposed outside the muffler container,
The silencer ventilation structure according to any one of claims 10 to 16, wherein the opening of the tubular body is opened on at least one side surface of the silencer container.   The silencer ventilation structure according to claim 18, wherein the tubular body is embedded in at least one of the wall and the decorative board in a state of protruding to at least one side of the wall and the decorative board.   The silencer ventilation structure according to any one of claims 10 to 19, wherein the tubular body is made of a sound insulating material.