JPH10102618A - Soundproof wall - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently reduce noise in a low frequency band by building a resonance absorption mechanism in a wall of a hollow or soled construction. SOLUTION: A resonance absorption mechanism 2 comprising a main body portion 21 having a cavity portion, a neck portion 22 having a air ventilation passage communicating with the cavity portion of the main body 21, and an opening 23 opened toward the indoor side at the neck portion 22 is built in a wall surface panel P thereby constituting a soundproof wall. A mechanism 2 utilizes the resonance phenomenon by the mass of air existing in air passage of the neck portion 22 and a spring component of air in the air cavity of the main body 21 and reduce and absorbs the standing wave occurred in the room. Also, the cross-sectional area of the opening portion 23, the volume of cavity of the main body portion 21, and the length of neck portion 22 are made freely adjustable and are accurately tuned to the standing wave changing in response to the situation inside the room. By doing this, the noise level in low frequency band, which is the most problematic among the impact sound of heavy weight to floor, can be efficiently reduced and the resonance sound absorbing mechanism can be arranged without projecting into the room, and also the noise insulation can be improved because of double wall construction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soundproof wall suitable for use in apartment buildings such as RC-structured condominiums, gymnasiums, office buildings, school classrooms and the like.

[0002]

2. Description of the Related Art For example, in an apartment house, a wall is provided for partitioning from another room or the like. At the same time, this wall has a function of preventing propagation to an adjacent room.

[0003] Therefore, regarding the noise generated indoors,
For example, by increasing the wall thickness, or by double wall,
By using a sandwich structure sandwiching a sound insulating material, and further using a wall or the like using a sound absorbing material, it is possible to reduce sound transmission to an adjacent room and the like, and also to reduce noise from an adjacent room and the like.

[0004]

However, such a conventional wall does not have a function of actively silencing the sound that has once entered the room. For low-frequency sound induced by the above, that is, standing wave, an effective reduction and sound absorbing effect cannot be obtained.

In view of the above circumstances, the present invention provides a soundproof wall capable of efficiently reducing noise (standing wave) in a low frequency band, which is a problem due to a floor impact sound from a weight source. It is intended for.

[0006]

That is, the first aspect of the present invention has a structure in which a resonance sound absorbing mechanism is incorporated in a wall having a hollow structure or a solid structure.

According to a second aspect of the present invention, the resonance sound absorbing mechanism includes a main body defining a hollow portion having a predetermined volume;
A neck defining a communication passage communicating with the hollow portion of the main body, and an opening that opens toward the outside of the neck,
A standing wave generated in a room where the air conditioner is installed is reduced and absorbed by utilizing a resonance phenomenon caused by a mass of air existing in a communication passage of the neck and a spring component of air in the hollow portion.

According to a third aspect of the present invention, the resonance sound absorbing mechanism has at least one opening, the volume of the hollow portion of the main body, the length of the communication passage of the neck, and the sectional area of the opening. At least one of them can be changed.

The invention according to claim 4 has a damping mechanism in the neck and / or the hollow portion.

[0010]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a soundproof wall 1 according to the present invention.
Has many resonance sound absorbing mechanisms 2 incorporated in each wall panel P in the room. The resonance sound absorbing mechanism does not need to be provided on all the walls, and may be provided, for example, only on a pair of opposed walls or on only one wall.

The resonance sound absorbing mechanism 2 includes a main body 21 having a hollow portion A (volume V) and a neck portion 2 having an air passage B (inner diameter d, length t) communicating with the hollow portion of the main body portion 21.
2 and an opening 23 that opens toward the outside (room) of the neck 22.

As shown in FIG. 2, the resonance sound absorbing mechanism 2 utilizes the resonance phenomenon caused by the mass of air existing in the air passage B of the neck portion 22 and the spring component of the air in the hollow portion A, and installs the resonance sound absorbing mechanism 2 in the room where it is installed. The generated standing wave (the first mode is depicted in FIG. 6) is reduced and absorbed, and the volume of the hollow portion A is V, the length t of the neck 22, and the opening cross-sectional area S (= π) of the neck 22.
d ^2/4), C is when the speed of sound, the resonant sound-absorption frequency F ₀ is the formula _{F 0 = (C / 2π)} · [S / V (t + 0.8d)] Kazuyoshi ^1/2 (1) Is determined.

Here, the resonance phenomenon is, as shown in FIG.
Similar to the resonance phenomenon of the spring-mass system in the mechanical system, the mass S · t · ρ of the air at the neck 22 (corresponding to the mass of the mechanical system)
And a resonance phenomenon due to an air spring component ρ · C ² · S / V (corresponding to a mechanical spring) in the cavity. Where ρ
Is the density of air.

On the other hand, the component frequencies F _X , F _Y , and F _Z in the (X, Y, Z) space of the unique standing wave generated in the room where the soundproof wall 1 is installed are the primary influences of the primary waves. For the standing wave of (However, L _X , L _Y , and L _Z are obtained by the room size in each component direction). Therefore, each parameter (S) is adjusted so that these values are tuned to the value of the resonance sound absorption frequency of Expression (1). , V, t, d) are set.

According to the present invention, in order to accurately tune to a standing wave that slightly changes according to the actual situation in the room in which the apparatus is installed, for example, as shown in FIG. Is provided with a variable mechanism 3 for fine-adjustment of. That is, the variable mechanism 3 is configured to rotate the opening 23 on the tip end side of the neck 22 (particularly, not limited to this configuration) to finely adjust the cross-sectional area.

In addition to the variable mechanism as in this embodiment, the sectional area of the opening is changed by, for example, opening and closing a diaphragm-shaped camera or exchanging a cap fitted into the opening. It may be. Further, as shown in FIG. 4, a partition 32 for changing and adjusting the volume of the hollow portion A is provided by the operating rod 31, or the length of the communication passage of the neck is changed and adjusted by appropriate means. There may be. In addition, gauze in the hollow part and the communication passage of the main body,
Cotton, urethane, cloth, mesh material or the like may be attached to generate the damping effect.

Therefore, according to this embodiment, since the resonance sound absorbing mechanism 2 is incorporated in a part of the door 1, a low frequency band (for example, 63 Hz,
31.5 Hz octave band) can be efficiently reduced. In addition, where the door is installed at a place where the sound pressure level in the low frequency band to be reduced is higher (for example, at an end or a corner of a room), the reduction effect is even greater.

Next, using another resonance sound absorbing mechanism (resonator) 2 according to the present invention, the volume is adjusted to an optimum volume V according to the installation, and is arranged on the third floor of a four-story apartment house.
According to JIS A1418, a tire drop evaluation experiment was performed using the second and third floors. In addition, about the resonance sound absorption mechanism 2 at this time, The resonator shown in FIG. 7 was used. Here, the volume V was made variable, and fine adjustment was made to the standing wave frequency of the actual room.

With the bang machine 5 shown in FIG. 8, five points on the third floor were vibrated, and the noise at that time was measured at five points on the second floor, and the data as average was obtained. The size of the room is about 3.6 x 2.7m, which is equivalent to 6 quires, and the height is 2.4m. Slab = 150 mm thickness and to approximate the standing wave in each direction (2) from the _{equation, L X (3.6m) = C} / 2L X ≒ 47Hz L Y (2.7m) = C / 2L Y ≒ 63Hz L Z a _{(2.4m) = C / 2L Z} ≒ 71Hz. When we measure the floor impact sound of this room, especially X
It was found that the noise due to the standing wave in the direction had the highest level. This is thought to be due to the arrangement of doors and windows in the room. Therefore, an experiment in the X direction was performed here. The standing wave of the actual room is 46Hz from the sound measurement,
Although it deviated from the approximate value of 47 Hz from the above equation (2), the resonator V was adjusted to 46 Hz by changing the volume V of the resonator (actually adjusted by moving the partition plate 41 in FIG. 7). (1) As shown in FIG. 9, the result of the octave band analysis was 63
The improvement of 4 dB in the Hz band, that is, the sound insulation class (L value) was raised by one rank. (2) As shown in FIG. 10, the result of the narrow band spectrum analysis was 4 times smaller than that without the resonance sound absorbing mechanism.
At a peak value of 6 Hz, a reduction of about 10 dB was observed. (3) As for the result of the time-series waveform analysis, as shown in FIG. 11, the decay time was significantly reduced as compared with the case where the resonance sound absorbing mechanism was not provided. Note that (2) and (3) are results measured from microphones other than the central microphone.

[0020]

As described above, according to the soundproof wall of the present invention, the soundproof wall is buried in the door even in a narrow place where there is no dedicated installation space. And the wall can be effectively used, and since the wall has a substantially double structure, the sound insulation is further improved.

Further, according to the present invention, it is possible to reduce the noise such as the sound of people jumping in the installed room, and even if the floor impact sound is in a room on the floor, it is possible to reduce the sound absorption in the floor below. Can be done

Further, according to the present invention, the solid-state noise due to the standing wave can be greatly reduced by installing a plurality of resonance sound absorbing mechanisms, increasing the volume of the hollow portion of the resonance sound absorbing mechanism, and increasing the sectional area of the opening. Can be increased.

Further, according to the present invention, by changing at least one of the neck portion (the length and the cross-sectional area of the communication passage) and the volume of the hollow portion of the resonance sound absorbing mechanism to a variable structure, it is possible to provide a finely detailed structure according to the condition of the room. Fine adjustments can be made.

Further, by attaching an appropriate attenuating material to the neck of the resonance sound absorbing mechanism or the hollow portion of the main body, the adjustment of the low frequency band and the amount of reduction can be further adjusted.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing a room equipped with a soundproof wall according to the present invention.

FIG. 2 is a schematic sectional view showing a main part of the soundproof wall.

FIG. 3 is a schematic perspective view showing a variable mechanism of the soundproof wall.

FIG. 4 is a schematic sectional view showing another variable mechanism of the soundproof wall.

FIG. 5 is a principle view showing the operation of the present invention.

FIG. 6 is an explanatory diagram showing a standing wave model.

FIG. 7 is a perspective view showing a resonator used in a tire drop evaluation experiment.

FIG. 8 is an explanatory view showing a tire drop evaluation experiment.

FIG. 9 is a graph showing an octave band analysis result.

FIG. 10 is a graph showing an analysis result of a narrow band spectrum.

FIG. 11 is a graph showing an analysis result of a time-series waveform.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Soundproof wall 2 Resonance sound absorption mechanism 21 Main part 22 Neck 23 Opening 3 Variable mechanism A Hollow part B Communication passage

Claims (4)

[Claims] 1. A soundproof wall characterized by incorporating a resonance sound absorbing mechanism into a hollow or solid structure wall. 2. A resonance sound absorbing mechanism, wherein a body defining a hollow portion having a predetermined volume, a neck defining a communication passage communicating with the hollow portion of the body, and an opening toward the outside of the neck. An opening is provided to reduce and absorb a standing wave generated in a room where it is installed by utilizing a resonance phenomenon caused by a mass of air existing in the communication passage of the neck and a spring component of air in the hollow portion. The soundproof wall according to claim 1, wherein: 3. A resonance sound absorbing mechanism having at least one opening, wherein at least one of a volume of a hollow portion of a main body, a length of a communication passage of a neck, and a sectional area of the opening can be changed. The soundproof wall according to claim 2, wherein: 4. The soundproof wall according to claim 2, wherein a damping mechanism is provided in the neck and / or the hollow portion.