JP2013164229A - Silencing ventilation device - Google Patents

Abstract

A silencer ventilator capable of improving sound insulation without increasing indoor air flow resistance is provided.
A silencer container 1 and a sound reduction device 2 are provided. The muffler container 1 is a hollow container having a sound absorbing material attached to the inner surface. The sound reduction device 2 includes a supply cylinder 22 and a resonance sound absorbing material 21. The supply cylinder 22 is a cylindrical body with both ends penetrating therethrough. A resonance sound absorbing material 21 is located at the end of the supply cylinder 22 on the sound deadening container 1 side. The resonant sound absorbing material 21 includes a cylindrical cavity 21 a having an inner diameter substantially the same as the inner diameter of the supply cylinder 22. It arrange | positions in the state in which the center axis | shaft of the supply cylinder 22 and the center axis | shaft of the cylindrical cavity part 21a correspond.
[Selection] Figure 1

Description

  The present invention relates to a silencer ventilator.

When the T-4 grade is required for the sound insulation performance of the sash, such as in the living room of an apartment house where there is a large amount of external noise, the natural air inlet for 24-hour ventilation installed adjacent to this sash must also have a sound deadening performance. Become.
In order to improve such a problem, the following structure has been conventionally developed.
<1> A retrofitted soundproof louver structure in which a maze-like sound absorbing material is installed in the external louver of the 24-hour ventilation air supply port to mute the sound.
<2> A glass duct flexible sound deadening structure in which a sound absorbing material is wound around a total heat exchange type air intake duct to mute the sound.
<3> A silencer structure with a built-in sleeve, in which a device with a sound absorbing material is fitted in the sleeve of the 24-hour ventilation supply port to mute the sound.
<4> As shown in Patent Document 1, a structure in which a ventilation device with a sound absorbing material is embedded in a wall.

Japanese Patent Laid-Open No. 10-281515

The conventional silencer ventilator described above has the following problems.
<1> As shown in FIG. 17, there is no effective means for preventing the resonance phenomenon of the 400 to 700 Hz band sound generated in the route pipe of the ventilation port and the accompanying significant sound insulation loss, and it is difficult to secure the T-4 grade. Met.
<2> Even if the inside of the path is uniformly sound-absorbed, the problem of the sound resonance phenomenon occurring in the ventilation path cannot be solved, and it is difficult to avoid a decrease in sound insulation performance at a specific frequency.
<3> There is no thing that secures the T-4 grade among those attached to the air inlet having an inner diameter of 150Φ.
<4> There are many products in which the size of the product itself is reduced by ensuring sound insulation performance and saving space. For this purpose, measures such as affixing a sound absorbing material in a maze shape to secure distance attenuation and a sound absorbing area, or reducing the air volume of the air inflow path are taken. As a result, there is a problem that the differential pressure between the living room and the outside air becomes large, and the opening and closing of the entrance door and the sash becomes heavy.
<5> As described above, in the prior art, there is no solution that solves the two contradictory problems of eliminating the pressure difference and ensuring the sound insulation performance.
<6> In a structure in which a flexible duct is installed, specialized equipment construction is required for installation such as duct expansion / contraction adjustment, support with a hanging bracket, and connection of a sleeve.

  In order to solve the problems as described above, the silencer ventilator of the present invention comprises a silencer container and a silencer, and the silencer container is a hollow container having a sound absorbing material attached to the inner surface thereof. It has an outdoor side ventilation opening that is open on one side and an indoor side ventilation opening that is open on the other side of the sound-absorbing container. On the other hand, the noise reduction device is composed of a supply cylinder and a resonance sound absorbing material, and the supply cylinder is a cylindrical body penetrating both ends, and the resonance sound absorption material is located at the end of the supply cylinder on the side of the sound deadening container. The resonance sound absorbing material has a cylindrical cavity having an inner diameter substantially the same as the inner diameter of the supply cylinder, and a silencer ventilator arranged so that the central axis of the supply cylinder and the central axis of the cylindrical cavity coincide with each other. It is a feature.

  Furthermore, in the silencer ventilator according to the present invention, the silencer ventilator is characterized in that a perforated cylinder is installed at the tip of the above-mentioned supply cylinder on the side of the silencer container, and a resonance sound absorbing material is disposed on the outer periphery of the perforated cylinder. Is.

  Furthermore, in the silencer ventilator according to the present invention, a silencer ventilator in which a rod-like or wire mesh-like support material is installed at the tip of the above-mentioned supply cylinder on the silencer container side, and a resonance sound absorbing material is arranged on the outer periphery of the support material. It is a feature.

Furthermore, in the silencer ventilator of the present invention, the resonance sound absorbing material located at the tip of the above-mentioned supply cylinder on the side of the silencer container is in a range of 18 to 70% with respect to the total axial distance of the supply cylinder and the resonance sound absorption material. More preferably, the silencer ventilator is arranged in the range of 18 to 34%.

Since the silencer ventilator of the present invention is as described above, the following effects can be obtained.
<1> The resonance phenomenon of the 400-700Hz band sound generated in the pipe from the ventilation port is absorbed by the resonance sound absorbing material of the sound reduction device, so that T-4 grade noise reduction performance can be secured, and pressure loss and air flow rate decrease. It can be installed without significantly reducing the conflicting performance.
<2> The silencer ventilator enables the T-4 grade sound insulation performance to be secured even at a natural air inlet having a diameter of 150 mm, which could not be realized by the conventional technology.
<3> High sound insulation performance is achieved over the entire frequency band by the outer wall side ventilation port, the indoor side ventilation port, and the sound deadening container provided between the two, provided with a height difference.
<4> Specifically, with respect to 100φ and 150φ ventilation openings, it was possible to achieve the T-4 grade of sound insulation performance without increasing the air flow resistance. Especially for 150φ, there is no marketed product with T-4 performance, so there is market advantage.

Explanatory drawing of the Example of the silencing ventilation apparatus of this invention. Sectional drawing of the Example of a sound reduction apparatus. Explanatory drawing of the other Example of a sound reduction apparatus. Explanatory drawing of the other Example of a sound reduction apparatus. Explanatory drawing of the other Example of a sound reduction apparatus. Explanatory drawing of the installation process of a sound reduction apparatus. Explanatory drawing of the installation state of a silencer ventilator. The figure which shows the ratio of the length of a resonant sound-absorbing material, and the change of level reduction amount. The figure which shows the sound transmission loss of the sound reduction apparatus of this invention. The figure which shows the pressure loss performance of the silencing ventilation apparatus of this invention. The figure which shows the pressure loss performance of the silencing ventilation apparatus of this invention. The figure which compared the pressure difference of the silencer ventilation apparatus of this invention, and a popular product. The figure which shows the effect by BME analysis. The comparison figure of the shape of a resonance sound absorption material. The figure which shows the calculation result of the sound absorption coefficient by the shape of the resonance sound absorbing material The figure which shows the state of the acoustic particle velocity at the time of using a simple cylinder. The figure which shows the sound insulation performance of the conventional apparatus.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

<1> Basic configuration The silencer ventilator of the present invention is constituted by a silencer container 1 in which a sound absorbing material is affixed, and a silencer 2 attached to an opening on the outdoor side of the silencer container 1.

<2> Silencer container 1
The sound deadening container 1 is a vertically long hollow container, and a sound absorbing material 11 is formed on the inner surface to form a sound deadening chamber 11.
As the sound absorbing material, a known fiber sound absorbing material such as glass wool, polyester resin PET material sound absorbing material, or the like can be used.
In the case of fiber sound-absorbing material, in the case of ventilation at high wind speed, the sound-absorbing material fiber may be scattered, which may impair the living environment, but the surface is covered with a covering material such as glass cloth or polyethylene film. If it is adopted, the scattering of the fibers can be prevented.
The silencing container 1 is a device that achieves a silencing effect by the sound-absorbing material lined in the interior. The outdoor vent 12 is opened on the outdoor surface below the silencing container 1.
An indoor side ventilation opening 13 is opened on the indoor side above the silencer 1.
That is, the outdoor side ventilation port 12 and the indoor side ventilation port 13 that are likely to receive noise on the outdoor side are not on the same axis, but are shifted in the vertical direction.
When the interval is large, the sound distance can be further attenuated by the difference in the position of the opening.
In the embodiment shown in the figure, the case where the outdoor side ventilation port 12 is provided at the lower side and the indoor side ventilation port 13 is provided at the upper side is described. However, the outdoor side ventilation port 12 is provided at the upper side and the indoor side ventilation is provided at the lower side. It is also possible to provide a mouth 13.

<3> Resonant Sound Absorbing Material A resonant sound absorbing material 21 is positioned on the indoor side of the feed cylinder 22 described later, that is, on the end of the sound deadening container 1.
The resonant sound absorbing material 21 is a material having a known sound absorbing function, such as glass wool, and many kinds of materials are developed and marketed.
However, instead of closing the tip of the supply cylinder 22 with the resonance sound absorbing material 21, the resonance sound absorption material 21 is formed with a cylindrical cavity 21 a having an inner diameter substantially the same as the inner diameter of the supply cylinder 22.
And the resonance sound-absorbing material 21 is disposed on the indoor side of the supply cylinder 22 and at the tip of the sound-absorbing container 1 in a state where the central axis of the supply cylinder 22 and the central axis of the cylindrical hollow portion 21a coincide. (Figure 2)
As will be described later, the arrangement of the resonance sound absorbing material 21 is such that the resonance sound absorbing material 21 is positioned at the tip of the supply cylinder 22 on the indoor side, that is, the silencer 1 side so that vibration is weakened at a place where the particle velocity of the sound wave is large. In this structure, a part of the air is guided by that part.

<4> Supply Cylinder A supply cylinder 22 is attached to the outdoor side ventilation opening of the silencer 1.
The supply cylinder 22 is a tubular body made of hollow steel, PVC or the like with both ends open.
Actually, the sleeve 22a is attached to the inner surface of the outer wall through-hole penetrating the outer wall of the building, and the supply cylinder 22 is inserted into the sleeve 22a so as to be integrated with the building.
The supply cylinder 22 is not limited to the full length of the sleeve 22a, but may be fitted to a part thereof.
The resonance sound absorbing material 21 is positioned on the indoor side of the supply cylinder 22, that is, on the silencer 1 side.

<5> Ratio of length The axial length of the cylindrical cavity 21a of the resonance sound absorbing material 21 is 18% to 70% with respect to the total axial length of the supply cylinder 22 and the cylindrical cavity 21a. Is more preferably in the range of 18% to 34%.
The grounds are as follows.
That is, the result of estimating the silencing effect (level reduction amount) of the present apparatus by analysis is as shown in FIG. 8, and it was found that the silencing effect changes according to the ratio of the resonance sound absorbing material 21 to the total length.
As shown in FIG. 8, the relationship between the ratio of the length of the range of [resonance sound absorbing material 21] to the range of [supply cylinder 22 + resonance sound absorbing material 21] and the amount of level reduction is a linear regression equation up to a certain range. (An improvement effect prediction formula) can be approximated. According to this, in order to realize T-4 to T-5, the resonance sound absorbing material 21 is positioned in the range of the length ratio 0.18 to 0.34. You can see that it is necessary.
Moreover, it can be read that the performance improvement limit by such a supply cylinder 22 and the resonance sound absorbing material 21 is up to a length ratio of about 0.7.

<6> Position for Resonance Sound Absorbing Material Arrangement If the resonance sound absorbing material 21 is disposed at any position, it can be said that the sound absorbing effect is improved as compared with the case where it is not disposed.
However, the structure of the present invention is particularly characterized in that the resonance sound absorbing material 21 is disposed at the end of the supply cylinder 22 on the sound deadening container 1 side.
The reason for determining the arrangement position is based on wave analysis.
That is, in the apparatus of the present invention, as shown in FIG. 16, by the wave analysis (boundary element method analysis), when the supply cylinder that is a simple cylinder and the silencer container 1 are combined, the particle velocity of the sound wave around the joint is obtained. It was made as a result of paying attention to the fact that it becomes higher.
By arranging the resonance sound absorbing material 21 in the portion where the particle velocity becomes high, the absorption effect of the sound wave particles that vibrate at a high speed is enhanced, and for the first time, the effect of attenuating the vibration energy of the sound wave particles with high efficiency can be realized. .
As described above, the resonance sound absorbing material 21 of the apparatus of the present invention does not have to be disposed at an arbitrary position, and particularly has a configuration provided at a specific position selected as a result of analysis.

<7> Support of Resonant Sound Absorbing Material Since the resonant sound absorbing material 21 is a flexible and low-strength material, there is a problem whether the shape of the inner surface of the cylindrical cavity portion 21a can be maintained for a long time depending on the material.
In this case, as shown in FIG. 3, a perforated tube 23 having the same diameter as that of the supply cylinder 22 is installed at the tip of the supply cylinder 22 on the indoor side and the silencer 1 side to support the resonance sound absorbing material 21 from the inner surface. .
The perforated cylinder 23 is a hollow cylinder, and a large number of sound absorbing holes 23a are opened on its surface.
If the resonance sound absorbing material 21 is arranged on the outer periphery of the perforated tube 23, the shape of the inner surface of the resonance sound absorbing material 21 can be maintained for a long time.
The larger the aperture ratio of the sound absorbing hole 23a, the more the sound absorbing effect, but the opening area is adjusted by the material of the resonant sound absorbing material 21 in order to maintain the shape of the cylindrical cavity 21a.
When the perforated tube 23 is provided, the same function can be expected even if the sheet-like resonant sound absorbing material 21 is wound around the outer periphery of the perforated tube 23 without forming the cylindrical cavity 21 a in the resonant sound absorbing material 21. can do.
The perforated cylinder 23 can be formed integrally with the supply cylinder 22 by opening a part of the supply cylinder 22 or the like.

<8> Other Support Structure A plurality of rods project as support members 24 at the tip of the supply cylinder 22 in parallel with the central axis of the supply cylinder 22, and the resonance sound absorbing material 21 is disposed around the support 24. You can also. (Fig. 4)
Alternatively, in order to maintain the shape of the resonant sound absorbing material 21, instead of the perforated tube 23, a tube such as a metal mesh 25, expanded metal, punched steel plate, or the like, which is an expanded state of the hole area of the perforated tube 23, is used. can do. (Fig. 5)

<9> Installation of supply cylinder (Fig. 6)
The case where the muffler container 1, the supply cylinder 22, and the resonance sound absorbing material 21 that have been divided and described above are installed in a building will be described. This installation order is for easy understanding of the description, and does not necessarily match the actual installation order.
A sleeve 22a, which is a cylindrical body, is attached to the outer peripheral wall in advance in a through hole that penetrates the inside and outside.
The supply cylinder 22 of the present invention is inserted into the sleeve 22a.
When the resonance sound absorbing material 21 is integrally attached to the indoor side of the supply cylinder 22, the supply cylinder 22 and the resonance sound absorption material 21 can be directly attached to the outer peripheral wall.
Alternatively, first, after inserting the supply cylinder 22 into the sleeve 22 a, the resonance sound absorbing material 21 is positioned on the indoor side of the supply cylinder 22.

<10> Attaching the silencer container (Fig. 7)
As described above, the sound deadening container 1 is a hollow container in which the resonance sound absorbing material 21 is attached.
The sound-absorbing container 1 is positioned on the indoor side of the resonant sound-absorbing material 21, the center of the outdoor ventilation opening 12 opened to the sound-absorbing container 1, the central axis of the supply cylinder 22, and the cylindrical hollow portion of the resonant sound-absorbing material 21. 21a is attached so that the central axes thereof coincide.
In the case of a structure in which the perforated tube 23 and the support member 24 are positioned on the indoor side of the resonance sound absorbing material 21, the resonance sound absorbing material 21 is disposed on the outer periphery thereof.
The weight of the sound deadening container 1 can be borne through a bracket protruding from the outer wall, or can be borne by the perforated tube 23 or the support member 24.

<11> Indoor Ventilation Vent As shown in FIG. 7, the silencing container 1 has an indoor ventilation vent 13 opened at a position different from the outdoor vent 12.
The greater the difference between the positions of the two vents 12 and 13, the better the silencing effect, but the lowering the venting effect. Therefore, considering the internal volume of the silencing container 1, the diameter of the vent, etc. To decide.
A commercially available internal register can be attached to the indoor side ventilation port 13 in the same manner as a normal ventilation port.

<12> Silence effect (Fig. 9)
FIG. 9 is a test example of the silencing effect in the apparatus of the present invention.
This test is an actual measurement result of the sound transmission loss from the outdoor side to the indoor side including the outdoor side ventilation opening and the supply cylinder 22 of the sound deadening container 1, but this test may reduce the sound transmission loss due to the resonance sound. I understand.
As apparent from this figure, according to the structure of the present invention, it was found that the T-4 grade of the sound insulation performance can be realized even in the ventilation holes of 100φ and 150φ.
In particular, at 150φ, since there is no commercial product having T-4 performance, a great market advantage can be expected.

<13> Reduction of internal / external differential pressure Conventional devices generally require a sound wave bending phenomenon for sound insulation. For this purpose, the sound insulation device is provided with a maze and an uneven mechanism.
However, these complicated mechanisms cause the differential pressure inside and outside the dwelling unit even if the sound insulation performance is improved.
The present invention simplifies these mechanisms, and does not extend the distance between the outdoor side and indoor side ventilation openings, and therefore can achieve an equivalent noise reduction effect without increasing the internal / external differential pressure.
10 and 11 show the pressure loss performance of the apparatus of the present invention.

<14> Comparison of internal and external differential pressure (Fig. 12)
The internal / external differential pressure due to the structure of the present invention described above is compared with a general popular product (manufactured by Shin Nikkei Co., Ltd., Clair).
Then, as a result of actual measurement, it was found that 100φ had a pressure loss reduction effect of about 1/8 in the case of 40 m 3 / h, compared with a general-purpose product having a silencer ventilation device and T-4 performance.

<15> Measurement of Examples An apparatus based on the above analysis results was manufactured and its effect was measured.
The manufactured structure is as shown in FIG. 13 in which the supply cylinder 22 and the perforated cylinder 23 are integrated, and the resonance sound absorbing material 21 is disposed on the outer periphery of the perforated cylinder 23.
A device having a total length of 226 mm of the supply cylinder 22 and the perforated cylinder 23 and a length of the resonance sound absorbing material 21 of 50 mm (length ratio 0.22) was used.
An analysis example of the silencing effect of this structure is shown in FIG.
This experiment is for confirming the sound reduction effect in the resonance range by BEM (Boundary Element Method) analysis.
As can be seen from FIG. 13, in the apparatus of the present invention, the relative value of the sound pressure level dB is greatly reduced in the vicinity of 580 Hz as compared with the case without the resonance sound absorbing material 21, and the configuration of the present invention is T-4. It was experimentally confirmed that the above was fully satisfied.

<16> Examination of incident angle It is known that the sound absorption coefficient of the resonance sound absorbing material 21 depends on the incident angle of the sound wave, and generally the sound absorption coefficient decreases when the incident angle reaches 90 °.
Here, the incident angle is an angle between the normal direction of the material surface and the sound wave incident direction, and the incident angle of 90 ° is a state in which the sound wave is incident in a direction parallel to the surface of the resonance sound absorbing material 21. .
The analysis confirms that the vibration direction of the acoustic particles at the time of resonance is substantially parallel to the sound absorbing surface of the resonant sound attenuator 2, and the incident angle in this case is close to 90 °.
As a result, it can be said that the basic type of this apparatus is in a disadvantageous condition in terms of sound absorption efficiency.

<17> Improvement of Incident Angle FIG. 15 shows the relationship between the incident angle and the sound absorption coefficient based on the acoustic impedance value of glass wool (density 32KG./m3, thickness 25mm) as a representative example of the porous resonance sound absorbing material 21. It is shown.
From this, it can be seen that the sound absorption rate of the 400 Hz and 700 Hz sounds corresponding to the resonance frequency rapidly decreases as the incident angle approaches 90 °, and the peak tends to appear around 45 ° to 60 °.
Therefore, also in this apparatus, it is possible to enhance the sound reduction effect by providing the angle of the sound absorbing surface of the resonance sound absorbing material 21 near this angle.
Specifically, considering the efficiency, the incident angle is limited to 45 °. (Fig. 14)
The reason for this is that there is a physical limit to setting the angle, and the peak of the sound absorption coefficient appears near the angle.
If the type of the apparatus in this case is called a “high absorption type”, the two patterns shown in the figure can be considered in consideration of not narrowing the air flow path.
These are more effective than the case where the performance of T-5 is required or the case where a sufficient sound absorbing portion length cannot be taken.

1: Silencer 2: Silencer 21: Resonant sound absorber 21a: Cylindrical cavity 22: Supply cylinder 23: Perforated cylinder

Claims (4)

Consists of a silencer container and a sound reduction device,
The sound deadening container is a hollow container with a sound absorbing material pasted on its inner surface,
An outdoor vent opening on one side of it,
Equipped with an indoor ventilation opening that is open on the other side of the sound deadening container,
The outdoor side vent and the indoor side vent are arranged at positions that do not correspond to the sound deadening container,
On the other hand, the sound reduction device comprises a supply cylinder and a resonance sound absorbing material,
The feed cylinder is a cylinder that penetrates both ends.
A resonance sound absorbing material is located at the end of the supply cylinder on the side of the sound deadening container,
The resonant sound absorbing material has a cylindrical cavity having an inner diameter substantially the same as the inner diameter of the supply cylinder,
The central axis of the supply cylinder and the central axis of the cylindrical cavity are arranged to coincide with each other.
Silent ventilation device. The silencer ventilator according to claim 1,
Install a perforated tube at the tip of the silencer side of the supply cylinder,
A resonance sound absorbing material is arranged on the outer periphery of the perforated tube,
Silent ventilation device. The silencer ventilator according to claim 1,
A rod-like or wire mesh-like support material is installed at the tip of the silencer side of the supply cylinder,
A resonant sound absorbing material is arranged on the outer periphery of the support material.
Silent ventilation device. The silencer ventilator according to claim 1,
The resonant sound absorbing material located on the silencer side of the cylinder is
It is arranged in the range of 18 to 70%, more preferably in the range of 18 to 34% with respect to the total axial direction distance of the supply cylinder and the resonance sound absorbing material.
Silent ventilation device.

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