WO2006134654A1 - Structure d’absorption acoustique - Google Patents

Structure d’absorption acoustique Download PDF

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Publication number
WO2006134654A1
WO2006134654A1 PCT/JP2005/011051 JP2005011051W WO2006134654A1 WO 2006134654 A1 WO2006134654 A1 WO 2006134654A1 JP 2005011051 W JP2005011051 W JP 2005011051W WO 2006134654 A1 WO2006134654 A1 WO 2006134654A1
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Prior art keywords
sound
wave
sound absorbing
absorbing material
configuration
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PCT/JP2005/011051
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English (en)
Japanese (ja)
Inventor
Yutaka Kataoka
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Yutaka Kataoka
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Application filed by Yutaka Kataoka filed Critical Yutaka Kataoka
Priority to PCT/JP2005/011051 priority Critical patent/WO2006134654A1/fr
Priority to JP2007521043A priority patent/JP4728331B2/ja
Publication of WO2006134654A1 publication Critical patent/WO2006134654A1/fr

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    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general

Definitions

  • the present invention relates to a wide-band sound wave, particularly in a space where sound absorption and modulation are required, such as audio visual, concert hall, living room, classroom, office / factory, vehicle, road noise barrier, and building wall.
  • the present invention relates to a sound absorbing structure capable of absorbing or insulating sound waves in a low frequency range.
  • a sound absorbing material that can cut off or absorb the sound of the band corresponding to it is also required in consideration of the surrounding environment that emits sound.
  • the frequency range of sound waves to be played is determined internationally (for example, in Dolby Digital, the minimum frequency is 20 Hz).
  • the lowest frequency that can be played is determined by the speed of sound (approx. 340 mZs) ⁇ longest side length (m) of the playback environment (sound speed Z longest side length).
  • the lowest frequency (internationally determined) cannot be played.
  • an existing sound absorbing material can only absorb sound waves having a frequency equal to a wavelength twice as long as its thickness (if the half wavelength is the thickness of the sound absorbing material, the sound waves are emitted and reflected).
  • the reflected sound in the frequency band and the transmitted sound in the wide frequency band that leaks outside reduce the working environment and cause noise pollution to the surroundings.
  • highway noise cannot be sound-insulated at low frequencies, and has become an environmental problem along with low-frequency pollution generated in buildings.
  • the present invention has been devised in view of the above-described problems.
  • the present invention makes it possible to reproduce a target bass sound in a small room without absorbing broadband sound waves and leaking them outside, and to prevent noise. It is intended to provide a sound absorbing structure that can prevent harm.
  • the present invention has been created by reconstructing the theory of sound absorption based on new knowledge to be described later, which is different from the conventional wave theory.
  • the process starts with the explanation of the conventional wave theory, describes the general properties of the sound absorbing material with the conventional structure, then presents new knowledge, and finally explains the structure of the present invention based on the new knowledge. .
  • Fig. 37 shows the positions of silent air molecules (indicated by circles) and the positions of air molecules of one-wavelength sound waves when only the first wave is oscillated. It is a drawing showing the contrast with the figure (resonance has occurred! /, What !, state).
  • the vertical and horizontal lines in the upper schematic diagram showing the position of air molecules in the silent state indicate that the range in which the molecules are bound and moved is limited. In this state, each air molecule is attracted to each other by the intermolecular force and is held in the state where it is bound by the panel.
  • the lower schematic diagram showing the position of the air molecules of the sound wave of one wavelength when the sound wave is oscillated only for the first wave below is the case where the wall 40 is on the left side and the sound wave is oscillated.
  • the sound waves are longitudinal dense waves, and the air molecules that mediate them are attracted to each other by the intermolecular force as described above and are bound together in the panel.
  • the part where the molecular density is coarse is the negative pressure region, and there is a point where there is no atmospheric pressure fluctuation after that, and the part where the air molecules on the right side are dense is the positive pressure region. It becomes a state that there is a point of nothing.
  • the air molecules on the left wall 40 side (the molecules in contact with the wall always do not move) and the air molecules on the right side move and show as! .
  • FIG. 38 is a graph (FIG. 38) showing the pressure change at a certain point when there is such a sound wave oscillation. 37 shows the pressure change at one point when sound waves are oscillated as shown in the lower figure.
  • the moving distance of the air molecules in the sound wave is about 0.1 mm even at a wavelength lm (assuming 360 Hz) and a large volume. In other words, it moves only about 1 / 10,000 of the wavelength. As the wavelength is longer, neighboring molecules move together, so the distance variation between the two molecules is less than when the wavelength is short. Therefore, the power to shake things is weakened. For this reason, low sounds can only be heard when they are loud.
  • FIG. 39 and FIG. 40 are a schematic diagram showing the position of air molecules when one wave of sound wave is emitted only in the first wave when there are parallel walls 40 and 41, and one piece of air. It is the figure which shows the pressure of a molecule
  • the negative pressure region indicated by arrows at both ends is the movement range of a certain air molecule. Since the air molecules in contact with the walls cannot move (the molecules in contact with both wall surfaces 40 and 41 do not move as shown in the figure), there is eventually one between the walls. Only a mountain and one valley (a mountain-valley pair) can be done. Therefore, the minimum resonance frequency is determined by the distance between the walls 40 and 41. If there is only one mountain or only one valley between walls (unpaired state), it cannot be made (depending on the fact that it cannot move to create such vibrations) .
  • a sound wave having a frequency lower than the minimum resonance frequency cannot be emitted. If the reflection-side wall 41 absorbs sound waves as shown in FIG. 42, reflection does not occur, and sound waves of low V and frequency can be emitted as much as possible.
  • a typical sound-absorbing material has a sponge-like shape (foam-like shape) in which air is dispersed and injected into plastic or the like, and soap bubbles are gathered together. Some of them are shaped by collecting and entwining fibers.
  • the former sound absorbing material is used for explanation. If the sound-absorbing material 50 is installed near one side with both wall surfaces 40 and 41 as shown in Fig. 39, it will be exactly as shown in Fig. 45.
  • the transmission efficiency increases if the pressure difference between the films is large (the same applies to the fiber type sound absorbing material). However, if the distance between the membranes is increased (that is, the bubble diameter is increased), the transmission medium (intervening between them) is reduced, so that the attenuation efficiency is deteriorated. On the other hand, when the film thickness is increased, the pressure difference can be increased before and after the film.
  • the film itself becomes a rigid body and the film itself does not shake due to air molecules (the film molecules Since there is no effect of being converted to heat by viscosity), the transmission efficiency is reduced (the same applies to fiber type sound absorbing materials).
  • the thinner the film thickness the more efficiently the vibrations of air molecules can be caught.
  • the ability to convert the vibrations of the film into heat is reduced and effective sound absorption is not possible.
  • the wave that passes through the sound absorbing material 50 and hits the wall 41 on the other side bounces off as it is.
  • the return wave (the bounce wave) No interference.
  • the lowest reproducible frequency in a specific room is determined by the length of the longest side of the room. However, if the sound wave is absorbed by the wall surface 41, reflection does not occur, and as a result, no resonance occurs, so that the lowest resonance frequency of the room can be lowered.
  • a longitudinal sound wave is converted into an air flow (transverse wave) by passing through a narrowed sound path in which the reduction rate of the opening area gradually decreases, and the sound is muted without depending on the wavelength. This is the knowledge that this is possible.
  • the volume of the molecule is not considered in the ideal gas handled by the wave theory formula, but in the actual air molecule, this phenomenon occurs because the nitrogen and oxygen molecules have a volume (excluded volume). To do.
  • the sound wave is compressed by the traveling direction and the central force of the sound path 12 (the reflection angle is gradually increased in the traveling direction).
  • the movement vector gathers in the direction of travel due to the viscosity of the air molecules, and the molecules are pushed out and compressed).
  • the position (vibration center) where there is a high pressure but there is no place for the molecule has to move (the intersection of the vertical line and the horizontal line on the drawing is the position that the molecule should originally be.
  • the travel direction is slightly smaller than that position, and further shifted toward the center of the sound path 12). This is a phenomenon that occurs because air is attracted to each other by intermolecular forces (high viscosity between molecules).
  • the dark colored molecules show that the binding positions (vibration centers) themselves of the air molecules are moving more greatly, while the light colored molecules are the binding positions of the air molecules ( Vibration center) itself moving force Less than dark colored molecules. That is, molecules closer to the constricted portion 11 wall surface 10 are compressed and shifted in the traveling direction and further toward the center of the sound path 12. In fact, the number of molecules is so large that it moves a distance much larger than the vibrational width of the molecule. On the other hand, such a shift is small at a position close to the center position of the sound path 12 of the constricted portion 11 (middle portion).
  • the air molecules are pulled backward, but the pulling force also weakens the shape force of the sound path as described above (because the cross-sectional area of the constricted part 11 of the sound path 12 is smaller than the entrance part) This is because the number of force molecules to be pulled back is small, so it is weaker than the entrance.)
  • the transverse wave continues to move to the right in Fig. 4 above.
  • the sound wave is compressed by the traveling direction and the central force of the sound path 12, that is, the reflection angle is gradually directed in the traveling direction. If the angle is changed, the movement vector gathers in the traveling direction due to the viscosity of the air molecule, and the molecule is pushed out and compressed. At that time, the wall 10 of the sound path 12 is high in pressure but has high molecular viscosity with no molecular destination (air is attracted to each other by intermolecular force and high in viscosity), so the vibration position has to move. .
  • Such movement of the vibrating position is converted into wind (transverse wave) (the vibrational force of each oscillating molecule shifts its original vibrational position force in the traveling direction of the center of the sound path 12,
  • the movement of the entire molecular group, ie, wind is applied to the dense wave, which is a longitudinal wave.
  • the narrower the narrowed portion 11 the greater the effect of converting the acoustic wave that is the longitudinal wave into the wind that is the transverse wave.
  • the sound wave with vibration is reflected to be dispersed on the wall surface 10 of the constriction 11 and is weakened during the reflection. End up.
  • the vertical line indicates the wavefront of the sound wave
  • the arrow line indicates the direction of the reflected sound.
  • the narrowed sound path has a fixed length and thus functions as a resonance tube. In other words, it greatly prevents the passage of sound waves with a wavelength equal to or longer than twice the length from the opening of the sound path to the center of the constriction.
  • the resonance phenomenon is intensified when the resonating frequency of sound waves continues, but strong resonance does not occur in the sound path where the reduction rate of the aperture area gradually decreases. Therefore, the sound wave that passes through the constriction becomes a sound wave having a wavelength shorter than the length of the sound path, and attenuates the sound wave having a frequency lower than that without passing through it.
  • the present inventor has further conceived of filling the sound absorbing material 20 into the sound path 12 configured as described above, as shown in FIG.
  • the function of the sound absorbing material 20 in this case is fundamentally different from the function of the sound absorbing material used as the conventional configuration described above.
  • the cross-sectional configuration is at least a configuration in which a sound absorbing material is filled in the sound path 12 in which the narrowed portion 11 is configured so that the reduction rate of the opening area gradually decreases on the entry side
  • the sound wave passing through the sound path 12 is gathered in the traveling direction as the air molecules constituting it gradually approach the narrowest constriction 11 from the entrance, and the molecules are pushed out and compressed.
  • the pressure of the molecule is high, but there is no place for molecules, and the viscosity of the molecule is high.Therefore, the vibration position moves and loses force, and this movement of the vibration position causes wind (transverse wave).
  • each oscillating molecule is its original
  • the vibrational position force of the sound path 12 also shifts in the traveling direction of the center position of the sound path 12, so that the coarse wave, which is a longitudinal wave, is moved into the entire molecular group, that is, converted into wind.
  • the configuration of the present invention is as described above.
  • the present inventor is not limited to the above-described configuration in which the reduction rate of the opening area gradually decreases on the entry side of the configuration of the constricted portion 11 of the sound path 12.
  • the increase rate of the opening area behind the narrowed portion 11 gradually increases. (Because it is formed in a curved surface), it has both the longitudinal and transverse wave characteristics that come out behind it. The wave was damped by causing the pressure (sound pressure) to drop and the speed to drop.
  • the first principle is that when the above-mentioned wave-like object passes through a rapidly expanding part, it is pulled by the attractive force between molecules of air, and the amplitude of molecules is hindered, rather than inversely proportional to the square of the distance. In other words, the sound pressure (sound volume) decreases, and this sound pressure decreases, so that the sound can be muted.
  • the second principle is that, as described above, the wind with non-uniform wind speed as shown by the thick line in FIG. Therefore, the sound can be muted without returning to the longitudinal wave (sound wave).
  • FIG. 6 is an explanatory diagram for explaining the principle of the decrease in the sound pressure. As shown in the figure, the positive pressure region from the shape in which the decrease rate of the opening area gradually decreases to the central constriction part 11 and the second half force of this constriction part 11 gradually increases the increase rate of the opening area. A reduced pressure region is formed.
  • the cross-sectional area through which the sound wave passes rapidly increases in an R shape, so that the sound pressure decreases. If the rate of increase of the opening area increases rapidly, as shown in the figure, the sound wave is not amplified (ie, the sound does not increase like a rat). Sounds below the frequency determined by the opening area and shape (sounds in the low frequency range) are reduced in sound pressure due to the properties of the rear horn as described above, and do not come out of the opening. Therefore, the bass cannot pass. That is, in the shape where the increase rate of the opening area gradually increases, the opening diameter rapidly increases toward the outer side, and the sound pressure decreases toward the lower sound side, so that it is attenuated.
  • the transverse wave that is, the wind itself
  • the longitudinal wave that is, the sound wave
  • FIG. 7 is an explanatory diagram for explaining the principle of the decrease in speed at a portion where the increase rate of the opening area gradually increases.
  • a deceleration region is formed from the second half of the central constricted portion 11 to a portion where the increase rate of the opening area gradually increases.
  • the sound wave is radiated like a point sound source from the narrowest point. As shown, it becomes spherical.
  • the sound wave is bent toward the opening at the right end. Similarly, the wind direction is also bent. At this stage, waves with both longitudinal and transverse properties are decelerated.
  • the present inventor has repeatedly studied the configuration for further increasing the attenuation efficiency of the waves having both the longitudinal wave and the transverse waves, and decided to use the following configuration.
  • a rear wall 30 parallel to the exit opening is provided at a position away from the exit rear of the portion where the increase rate of the opening area gradually increases.
  • the force of depressurizing and decelerating is expected. Furthermore, with the configuration substantially the same as the first configuration of the present invention, even a slight sound wave is completely converted into an air flow, and the wavelength is changed. It is muted without depending. Further, the fine sound wave is reflected so as to be dispersed between the wall surface 10 and the rear wall surface 30 of the constriction 11 and is weakened during the reflection. That is, at the same time as the sound pressure is lowered, the tip of the wavefront is almost spherical and hits the rear wall 30 little by little, so that the force that pushes the rear wall 30 of the converted sound wave weakens. Therefore, the rear wall surface 30 is located behind the exit side where the increase rate of the opening area is large. As long as it is installed parallel to the mouth, it does not work even if it is a wall of the room (no need to make a special wall).
  • the above configuration is further provided with a plurality of constrictions 11 parallel to each other so that the entrance side opening force of the constrictions 11 is arranged in a plane.
  • a sound absorbing structure having a constricted portion configured such that the rate of decrease in the opening area gradually decreases on the entry side, and conversely the rate of increase in the opening area gradually increases on the exit side.
  • the rear opening 30 has a parallel rear wall 30 (see Fig. 10).
  • the wind that flows along the wall 10 that spreads behind, and that flows along the flow sideways crosses the cross-section side by side. Therefore, both wind pressure and speed are almost zero. At this time, even if the wind contains vibration components, they collide with each other in the opposite direction, and the vibration and wind cancel each other.
  • this configuration has a configuration having the narrowed portion 11 that configures the sound path 12, and the configuration of the narrowed portion 11 has a reduction rate of the opening area at least on the entry side as a cross-sectional configuration.
  • Force that is configured to gradually decrease, or conversely on the exit side, the increase rate of the opening area is gradually increased, for example, two or more cylinders in parallel at regular intervals When it is provided and the plane force is also seen, such a configuration is formed between the cylinders.
  • the rear wall 30 may also be provided on the rear side.
  • the constricted portion 11 (of course has an entrance side opening and an exit side opening) on two planes facing a cylinder or a prism (including a polygonal column), and at least the entrance side is included.
  • the opening may be provided with a structure in which the opening area needs to be configured so that the reduction rate of the opening area gradually decreases), and it is easy to create a block shape with a mold. ).
  • a plurality of the constricted portions 11 can be provided continuously in the direction of the sound path 12 so as to be assembled in a flat shape or to communicate with the sound path 12.
  • the sound absorbing / muffling effect of the sound absorbing structure according to the present invention is enhanced.
  • the absorption structure according to the present invention described above, there is no constant reflection distance between the structure and the wall (including the rear wall surface 30) facing the structure, so that a resonance node cannot be created. Since resonance does not occur, resonance in a closed space can be prevented.
  • the present invention enables uniform sound absorption independent of thickness, size, and frequency, and at the same time, the sound wave attenuation rate on the exit side of this structure takes a large value regardless of frequency. .
  • the sound absorbing structure according to claim 1 is configured so that the reduction ratio of the opening area gradually decreases at least on the entrance side of the sound path through which the sound wave passes, which is composed of wall surfaces.
  • the basic feature is that it has a stenosis part.
  • the sound absorbing structure of claim 3 has a cross-sectional configuration of a sound path through which sound waves pass, which is constituted by a wall surface, and the reduction rate of the opening area gradually decreases on the entry side, and reverses on the exit side. It has a narrowed portion configured such that the increase rate of the opening area gradually increases.
  • the sound absorbing structure according to claim 5 is characterized in that a rear wall surface parallel to the exit opening is provided at a position away from the exit side of the sound path of the structure according to claim 3.
  • a sound absorbing structure according to claim 7 is characterized in that a plurality of the sound absorbing structures according to claim 3 are provided in parallel so as to be arranged in a plane.
  • the sound absorbing structure according to claim 9 is provided with a plurality of the sound absorbing structures according to claim 3 arranged in parallel so as to be arranged in a plane, and has a rear wall surface parallel to the outlet opening. It features.
  • FIG. 1 is a schematic explanatory diagram showing a basic configuration of the present invention.
  • FIG. 2 is a diagram illustrating the principle of the above configuration.
  • FIG. 3 is also an explanatory diagram of the principle of the configuration of the present invention.
  • FIG. 4 is an explanatory diagram showing the direction of sound wave reflection in the present invention.
  • FIG. 5 is a configuration explanatory view of the present invention in which a sound absorbing material 20 is filled in a sound path 12.
  • FIG. 6 is an explanatory diagram for explaining the principle of sound pressure reduction according to the configuration of the present invention.
  • FIG. 7 is an explanatory diagram for explaining the principle of the decrease in speed at a portion where the increase rate of the opening area gradually increases.
  • FIG. 8 is a diagram illustrating the configuration of the present invention having a rear wall surface 30 parallel to the outlet opening.
  • FIG. 9 is a structural explanatory view of the present invention in which a plurality of sound absorbing structures having the narrowed portion are provided in parallel so as to be arranged in a plane.
  • FIG. 10 is a structural explanatory view of the present invention further having a rear wall surface 30 parallel to the outlet opening.
  • FIG. 11 is a plan sectional view showing the internal structure of an anechoic chamber 60 used in the example of the present invention.
  • FIG. 12 is an explanatory diagram showing a schematic configuration of an internal structure of an anechoic chamber 60 used for comparison in each example.
  • FIG. 13 is an explanatory diagram showing a configuration in which the configuration of the constricted portion 11 is used inside the anechoic chamber 60 as Example 1.
  • FIG. 14 is a schematic diagram schematically showing the sound wave measurement state of FIG.
  • FIG. 15 is a schematic diagram schematically showing the sound wave measurement state of FIG.
  • FIG. 16 is a graph of measurement results obtained by obtaining the reflectance and transmittance in the case of FIG. 15 based on FIG.
  • FIG. 17 is a schematic diagram of a configuration in which the fibrous sound absorbing material 20 is filled in the constricted portion 11 in FIG.
  • FIG. 18 is a graph of measurement results obtained by obtaining the reflectance and transmittance in the case of FIG. 17 based on FIG.
  • FIG. 19 is an explanatory diagram showing a configuration according to Example 3.
  • FIG. 20 is a graph of measurement results obtained by obtaining the reflectance and transmittance in the case of FIG. 19 based on FIG.
  • FIG. 22 is a graph of measurement results obtained by obtaining the reflectance and transmittance in the case of FIG. 21 based on FIG.
  • FIG. 24 is a graph of measurement results obtained by obtaining the reflectance and transmittance in the case of FIG. 23 based on FIG.
  • FIG. 26 is a graph of measurement results obtained by obtaining the reflectance and transmittance in the case of FIG. 25 based on FIG.
  • FIG. 28 is a graph of measurement results obtained by obtaining the reflectance and transmittance in the case of FIG. 27 based on FIG.
  • FIG. 29 is an explanatory diagram showing the configuration according to the eighth embodiment.
  • FIG. 30 is a graph of measurement results obtained by obtaining the reflectance and transmittance in the case of FIG. 29 based on FIG.
  • FIG. 31 is an explanatory diagram showing a configuration according to the ninth embodiment.
  • FIG. 33 is an explanatory diagram showing a configuration according to Example 10.
  • FIG. 34 is a graph of measurement results obtained by obtaining the reflectance and transmittance in the case of FIG. 33 based on FIG.
  • FIG. 35 is a perspective view showing a configuration in which the narrowed portion 11 of the present invention is drilled in two planes facing a quadrangular column 64.
  • FIG. 36 is a perspective view showing a configuration in which the sound absorbing material 20 is provided in the sound path of FIG.
  • FIG.37 A diagram showing the position of silent air molecules, and the sound wave oscillated only for the first wave.
  • FIG. 39 is a schematic diagram showing the positions of air molecules when a sound wave of one wavelength is emitted only for the first wave when there are parallel wall surfaces 40 and 41.
  • ⁇ 41 It is an explanatory view showing a state when sound waves are reflected on the wall surface 41.
  • FIG. 42 is an explanatory view showing a state where the sound wave is absorbed and no reflection occurs.
  • FIG. 43 is an explanatory view showing that resonance occurs between the wall surfaces 41 that are not parallel to the wall surfaces 40. [44] It is an explanatory diagram showing a state where the sound disappears due to the overlapping of waves with slightly different phases.
  • FIG. 45 is an explanatory diagram showing a state in which the sound absorbing material 50 is installed between the wall surfaces 40 and 41 near one side.
  • a speaker 70 is installed in the center of the front of the drawing so that it can output toward the interior of the room, and a wall 61 is formed in the shape of a barrel in the cross section on the left and right around the center.
  • the bottom wall 62 is formed in a single section in a state of protruding into the barrel-shaped enclosure wall 61, and is formed into a cone shape by these enclosure walls 61, 62.
  • a foaming sound absorbing material 50 is filled between the anechoic chamber 60 and the inner surface.
  • the enclosure wall 61 has a structure in which a perforated board that is damped is covered with a high-density fibrous sound-absorbing material.
  • the ultra-low frequency special anechoic chamber 60 has a lm-thickness sound absorbing material (foaming sound-absorbing material) with no parallel part to the floor at the ceiling, and a 60cm-thick sound absorbing material at the floor.
  • a sound absorbing material (same material) with a quadrangular pyramid structure (same material) and a height of lm is attached.
  • this special low-frequency anechoic chamber 60 is installed on a base isolation table.
  • the minimum resonance frequency of the ultra-low frequency special anechoic chamber 60 is set to 4.2 Hz, and the minimum vibration resonance frequency of the floor surface is about 7.6 Hz.
  • the anechoic chamber 60 is installed in an anechoic chamber, and is in a state of 35 (1 ⁇ / ⁇ V or less) in a measurement range of 40 KHz to 17 GHz.
  • the speaker 70 is a Dunlavy custom-made sealed speaker and has the following characteristics.
  • an ultra-low frequency special anechoic chamber 60 is installed.
  • the sound insulation walls 63a and 63b are installed so as to protrude inwardly from the left and right sides of the enclosure wall 61, whereby the anechoic chamber 60 is divided into a front chamber and a rear chamber. It was like that.
  • a sound absorbing material 50 made of the same material as above was attached to the front indoor side of the sound insulation walls 63a and 63b.
  • FIG. 13 shows the configuration according to claim 1 of the present invention, that is, the cross-sectional configuration force thereof, and the sound path having the constricted portion 11 configured so that the reduction rate of the opening area gradually decreases on the entry side.
  • a cylinder with a diameter of 11 cm was cut into a cross section of 1Z4, and a cylinder with a cross section of 1Z4 was provided between the sound insulation walls 63a and 63b with a 8 mm gap between the narrowest portions 11 (opening side force).
  • S speaker 70 side
  • the ldB is 7 Hz to the output side of the speaker 70 in the front chamber of the anechoic chamber 60 and the character-shaped bottom wall surrounding the cross section of the rear chamber in the vicinity of the wall 62.
  • the Earthworks custom microphones 80 and 81 with 36KHz characteristics are installed, respectively.
  • the pulse sound wave emitted from the speaker 70 is picked up by the microphones 80 and 81, and the pulse type frequency analyzer (not shown) can record the PCM with 22BitZ96KHz linear. ). Since the pulse sound wave includes all frequencies, the frequency and its intensity can be known by FFT.
  • FIG. 14 schematically shows the sound wave measurement state of FIG. 12, and FIG. 15 schematically shows the sound wave measurement state of FIG.
  • the above measurement was performed, and the reflectance and transmittance in the case of FIG. 15 were obtained with reference to FIG. 14, and the measurement result of FIG. 16 was obtained. From the figure, the transmittance varies around 600Hz, but even above that ( ⁇ 20KHz), the transmittance in the state of Fig. 15 is less than 10% of Fig. 14, and the transmittance is reduced. Sound absorption effect was confirmed.
  • the reflectance is 1% in the case of Fig. 14 in any frequency band. Less than and low. Furthermore, with a slight supplement to the above diffraction, the sound path formed by the constriction 11 in FIG.
  • Fig. 15 has a reverse horn structure, so that low frequencies cannot pass.
  • the sound that can be passed is much less than the opening area of Fig. 15 (effective opening area is about 50%).
  • Fig. 16 the value of 40Hz or less increases due to vibration transmitted through the floor.
  • FIG. 17 shows a schematic diagram of the state in which the fibrous sound-absorbing material 20 is filled with 140 kgZm 3 in the constricted portion 11 in FIG. 13 (configuration of claim 2).
  • the above measurement was performed, and the reflectance and transmittance in the case of FIG. 17 were obtained with reference to FIG. 14, and the measurement results shown in FIG. 18 were obtained.
  • the transmittance is clearly lower in the state of FIG. 17 than in the state of FIG. 14, confirming the sound absorption effect.
  • the reflectivity is suppressed to be lower than that shown in FIG. 16 in any frequency band.
  • the thickness of the sound absorbing material 20 is 5.5 cm at the maximum, and when it is filled, sound is absorbed to 1Z10 or less than in the case of FIG. If sound was absorbed only with a fibrous sound absorbing material with a maximum thickness of 5.5 cm, it was not so much absorbed.
  • FIG. 19 shows a configuration according to claim 3 of the present invention, that is, its cross-sectional configuration, in which the decreasing rate of the opening area gradually decreases on the entry side, and conversely, the increasing rate of the opening area on the exit side.
  • a sound path having a constriction 11 configured to gradually increase is constructed. Specifically, a cylinder with a diameter of 11 cm was cut into a cross section of 1Z2, and a cylinder with a cross section of 1/2 was provided between the sound insulation walls 63a and 63b with an interval of 8 mm between the narrowest portions of the narrowed portion 11 (opening). (Side cap is facing 70).
  • FIG. 19 A state in which the fibrous sound-absorbing material 20 is filled in the constricted portion 11 in Fig. 19 at 140kgZm 3 (contract).
  • a schematic diagram of the configuration of claim 4 is shown in FIG.
  • the above measurement was performed, and the reflectance and transmittance in the case of FIG. 21 were obtained with reference to FIG. 14, and the measurement results shown in FIG. 22 were obtained. From the figure, the transmittance is clearly lower in the state of FIG. 19 than in the state of FIG. 14, confirming the sound absorbing effect. Also, the reflectivity is kept low in any frequency band as in FIGS. 16, 18, and 20.
  • the configuration of claim 6 is created (see Fig. 25) having a rear wall 30 parallel to the exit opening at a position away from the exit side of the sound path (see Fig. 25). Measurement was performed. With reference to Fig. 14, the reflectance and transmittance in the case of Fig. 25 were obtained, and the measurement results shown in Fig. 26 were obtained. From the figure, the transmittance was clearly lower in the state of FIG. 25 than in the state of FIG. 14, confirming the sound absorbing effect. Also, the reflectivity is kept low in any frequency band as in FIGS. 16, 18, 20, 20, 22, and 24.
  • FIG. 27 shows a configuration according to claim 7 of the present invention, that is, its cross-sectional configuration, in which the decreasing rate of the opening area gradually decreases on the entry side, and conversely, the increasing rate of the opening area on the exit side.
  • a sound path having a constricted portion 11 configured to gradually increase is created, and three sound path structures are provided in parallel so as to be arranged in a plane. Specifically, two cylinders with a diameter of 11 cm are provided in the center, with the narrowest part interval 8 mm between the two constrictions 11 formed between them, and are continuous with these cylinders as seen in cross section.
  • the semi-circular cylinders with the same cross-section as above are arranged in parallel (a structure between the central cylinder and the semi-cylinders at both ends. Between the sound insulation walls 63a and 63b, with these cylinders and semi-cylinders, there is a configuration with three constrictions 11 (all open sides) Force S-speech force 70)
  • FIG. 29 shows a schematic diagram of the state in which the fibrous sound-absorbing material 20 is filled with 140 kgZm 3 in the narrowed portion 11 of FIG. 27 (configuration of claim 8).
  • the above measurement was performed, the reflectance and transmittance in the case of FIG. 29 were obtained with reference to FIG. 14, and the measurement results shown in FIG. 30 were obtained. From the figure, the transmittance is clearly lower in the state of FIG. 29 than in the state of FIG. 14, and a remarkable sound absorbing effect was confirmed.
  • the reflectivity can be kept low in any frequency band, as in FIGS. 16, 18, 20, 20, 22, 24, 26, and 28.
  • the configuration of claim 9 is created (see Fig. 31) having a rear wall 30 parallel to the exit opening at a position away from the exit side of the sound path (see Fig. 31). Measurement was performed. Based on Fig. 14, the reflectance and transmittance in the case of Fig. 31 were obtained, and the measurement results shown in Fig. 32 were obtained. From the figure, the transmittance is clearly lower in the state of FIG. 31 than in the state of FIG. 14, and a remarkable sound absorbing effect was confirmed. Also, the reflectance is kept low in any frequency band, as in FIGS. 16, 18, 20, 20, 22, 24, 26, 28, and 30.
  • FIG. 33 shows a schematic view of the narrowed portion 11 of FIG. 31 filled with the fibrous sound absorbing material 20 at 140 kgZm 3 (configuration of claim 10).
  • the above measurement was performed, and the reflectance and transmittance in the case of FIG. 33 with respect to FIG. 14 were obtained, and the measurement result shown in FIG. 34 was obtained. From the figure, the transmittance is clearly lower in the state of FIG. 33 than in the state of FIG. As a result, a remarkable sound absorbing effect was confirmed. Also, the reflectivity is kept low in any frequency band as in FIGS. 16, 18, 20, 20, 22, 24, 26, 28, 30, and 32.
  • the LO has the cross-sectional configuration of two columns (in a state of being cut into 1Z4 and 1Z2) arranged in parallel, and each of the present invention described above.
  • the experimental results in the case of this state are shown.
  • the constricted portion 11 having the above shape is formed in two planes facing the quadrangular prism 64, or as shown in FIG.
  • the sound path 12 including 11 is preferably filled with the sound absorbing material 20.
  • it has an entrance-side opening and an exit-side opening, and at least the entrance-side opening needs to be configured so that the reduction rate of the opening area gradually decreases. Therefore, it is preferable that the increase rate of the opening area gradually increases.
  • Such a configuration can be created in a block shape with various materials.
  • a plurality of the constricted portions 11 are continuously provided in the direction of the sound path 12 so as to be assembled in a planar shape or to communicate with the sound path 12, so that the sound absorption according to the present invention is achieved. Sound absorption and silencing effect of the structure can be expected to increase easily.
  • the sound absorbing structure of the present invention absorbs sound uniformly over a wide range of sound wave frequencies, so that it can be tuned at audio visuals, concert halls, theaters, cinemas, classrooms and offices, etc. It can be used to generate low frequencies from vehicles and buildings, to prevent noise in vehicles, and to insulate buildings and rooms. Broadband in spaces that require sound absorption and tuning, such as road insulation walls and building walls. It is possible to absorb or sound-insulate sound waves, particularly low-frequency sound waves. / vD / O IsonosooifcId900iAV

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  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Multimedia (AREA)
  • Building Environments (AREA)
  • Devices Affording Protection Of Roads Or Walls For Sound Insulation (AREA)
  • Soundproofing, Sound Blocking, And Sound Damping (AREA)

Abstract

Le problème à résoudre dans le cadre de cette invention concerne une structure d’absorption acoustique capable d’empêcher les ondes acoustiques dans une large bande de sortir en les absorbant, en reproduisant une nuance voulue dans une pièce restreinte, et en empêchant l’apparition du bruit. La solution proposée consiste à créer une structure d’absorption acoustique qui comprend un canal de son composé de surfaces murales et qui laisse passer les ondes acoustiques. Le canal de son comprend une partie rétrécie, dans sa section transversale, formée de telle manière que le taux de diminution de sa zone diminue progressivement au moins sur son côté d’entrée.
PCT/JP2005/011051 2005-06-16 2005-06-16 Structure d’absorption acoustique WO2006134654A1 (fr)

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PCT/JP2005/011051 WO2006134654A1 (fr) 2005-06-16 2005-06-16 Structure d’absorption acoustique
JP2007521043A JP4728331B2 (ja) 2005-06-16 2005-06-16 吸音構造

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8919048B2 (en) 2012-07-31 2014-12-30 Interman Corporation Mobile terminal booth
WO2015012379A1 (fr) 2013-07-25 2015-01-29 インターマン株式会社 Cabine pour terminal portable

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5288301A (en) * 1976-01-19 1977-07-23 Hiroshi Kofujita Surge direction transmissive device
JPS62124106U (fr) * 1986-01-30 1987-08-06
JPH0764564A (ja) * 1993-08-31 1995-03-10 Nissan Motor Co Ltd 遮音構造及び遮音板
JPH10254456A (ja) * 1997-03-07 1998-09-25 Nissan Motor Co Ltd 遮音板構造
JP2004150185A (ja) * 2002-10-31 2004-05-27 Takamura Sogyo Kk 車両通行帯における防音壁の施工方法
JP2004169394A (ja) * 2002-11-20 2004-06-17 Takamura Sogyo Kk 車両通行帯における防音プレート
JP2005031240A (ja) * 2003-07-09 2005-02-03 Nakanishi Metal Works Co Ltd 吸音パネルおよび吸音装置

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6331117Y2 (fr) * 1980-09-11 1988-08-19
JPS5754200A (ja) * 1980-09-19 1982-03-31 Chugai Pharmaceut Co Ltd Suteroidojudotainoseizoho
JPH0694487B2 (ja) * 1985-11-26 1994-11-24 東邦チタニウム株式会社 オレフイン類重合用触媒

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5288301A (en) * 1976-01-19 1977-07-23 Hiroshi Kofujita Surge direction transmissive device
JPS62124106U (fr) * 1986-01-30 1987-08-06
JPH0764564A (ja) * 1993-08-31 1995-03-10 Nissan Motor Co Ltd 遮音構造及び遮音板
JPH10254456A (ja) * 1997-03-07 1998-09-25 Nissan Motor Co Ltd 遮音板構造
JP2004150185A (ja) * 2002-10-31 2004-05-27 Takamura Sogyo Kk 車両通行帯における防音壁の施工方法
JP2004169394A (ja) * 2002-11-20 2004-06-17 Takamura Sogyo Kk 車両通行帯における防音プレート
JP2005031240A (ja) * 2003-07-09 2005-02-03 Nakanishi Metal Works Co Ltd 吸音パネルおよび吸音装置

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8919048B2 (en) 2012-07-31 2014-12-30 Interman Corporation Mobile terminal booth
US8978314B2 (en) 2012-07-31 2015-03-17 Interman Corporation Mobile terminal booth
WO2015012379A1 (fr) 2013-07-25 2015-01-29 インターマン株式会社 Cabine pour terminal portable

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JPWO2006134654A1 (ja) 2009-01-08

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