JP7244679B2 - double skin structure - Google Patents

Description

The present invention relates to a double-skin structure that constitutes an outer wall of a building.

As one of the exterior walls employed to enhance the heat insulation performance of buildings, one having a double skin structure is known. In such a double-skin structure, a space (ventilation space) is provided between an outer member (outer skin) and an inner member (inner skin). In summer, in order to prevent the temperature in this space from rising, an opening is provided between the outer skin and the inner skin or in a part of the outer skin to ensure the introduction of outside air into the ventilation space and the circulation of air. .

For example, Patent Document 1 (Japanese Patent Application Laid-Open No. 2013-181333) discloses a double-skin structure consisting of a frame-shaped PC unit, which protrudes from the left and right front of the frame of the PC unit to block solar radiation from the left and right. an outer sash that is driven into the sleeve wall and on which an outer side member can be installed; an inner sash that is arranged opposite the outer sash via a hollow layer and on which an inner side member can be installed; A double-skin structure is disclosed in which a wall is provided with a communication port that communicates with the outside and the hollow layer, and a stepped portion is formed on the outside of at least one side surface of the sleeve wall.
JP 2013-181333 A

An exterior wall with a double-skin structure contributes to temperature control within a building by ventilating from the open end into the ventilation space between the outer member (outer skin) and the inner member (inner skin). It becomes possible. On the other hand, however, there is a problem that the opening edge becomes a sound insulation defect, and the sound insulation performance of the exterior wall having the double-skin structure is greatly reduced compared to the case where there is no opening edge.

At frequencies where the width of the ventilation space in the double-skin structure is less than half the wavelength of the sound wave, noise propagates two-dimensionally in the ventilation space. For this reason, the distance attenuation of the noise propagating upward from the lower open end is smaller than that of the noise propagating in the three-dimensional space. For example, for a point source, the distance attenuation in three-dimensional space is -6 dB as the distance from the source is doubled, but in two-dimensional space it is -3 dB.

Therefore, in an exterior wall with a double-skin structure, on the upper floors, the inner member (inner As the sound pressure level of the external noise incident on the skin becomes high, a member with higher sound insulation performance may be required, and there is also the problem of high cost.

Until now, there have been no proposals to solve the problems of the double-skin structure such as the deterioration of the sound insulation performance as described above, which is a problem.

The present invention solves the above problems, and the double-skin structure according to the present invention is an outer wall of a building comprising an outer member and an inner member provided on the indoor side of the outer member at a predetermined distance. A sound insulation plate is attached to the inner member, and the sound insulation plate is installed so that its tip is located outside a line connecting the noise source and the lower end of the outer member. It is characterized by
Further, the double-skin structure according to the present invention is a double-skin structure that constitutes an outer wall of a building, comprising an outer member and an inner member that is provided on the indoor side of the outer member at a predetermined distance, and is a sound insulation structure. A plate is attached to the outer member and the inner member in a staggered manner.
Moreover, the double skin structure according to the present invention is characterized in that a sound absorbing material is provided on the lower surface of the sound insulating plate.

In the double-skin structure according to the present invention, for example, a sound insulating louver provided with a resonator having an acoustic impedance ratio of 0 is arranged between the outer member and the inner member. The sound insulating louver has a function of securing the gap between the louver blade members as a ventilation path while preventing noise from propagating through the ventilation path. This function prevents outdoor noise from propagating into the air layer from the open end of the double-skin structure. As a result, according to the double skin structure according to the present invention, while maintaining the introduction of outside air into the air layer and the circulation of air, the opening end is prevented from becoming a sound insulation defect, and the sound insulation performance of the double skin structure is improved. can be improved.

Further, according to the double-skin structure of the present invention, the sound pressure level of noise incident on the inner member (inner skin) is reduced by preventing outdoor noise from propagating from the opening end into the air layer. . As a result, the inner member (inner skin) does not need a member with high sound insulation performance, and the cost can be reduced. For example, the inner member (inner skin) can be made of thin glass.

Moreover, since the sound insulation louver and the sound insulation plate used in the double skin structure according to the present invention are elongated bodies having the same cross section, they are easy to manufacture and install.

It is a figure explaining the principle of the sound insulation louver 1 used for this invention. FIG. 3 is a diagram illustrating a resonator 10 used in the sound insulation louver 1 used in the present invention; It is a figure which shows the sound insulation louver 1 used for this invention. Fig. 3 shows a double-skinned structure 301 according to an embodiment of the invention; Fig. 2 shows another sound insulation louver 1 used in the present invention; Fig. 10 is a diagram showing a louver blade member 210 used in another sound insulation louver 1 used in the present invention; Fig. 2 shows another sound insulation louver 1 used in the present invention; FIG. 5 is a diagram for explaining the principle of another sound insulation louver 1 used in the present invention; FIG. 5 is a diagram for explaining the principle of another sound insulation louver 1 used in the present invention; Fig. 3 shows a double-skinned structure 301 according to another embodiment of the invention; Fig. 3 shows a double-skinned structure 301 according to another embodiment of the invention; FIG. 4 is a diagram schematically illustrating noise transmission with or without a sound insulating plate 330; FIG. 10 is a diagram illustrating a sound insulating plate 330 provided with standing portions 335; Fig. 3 shows a double-skinned structure 301 according to another embodiment of the invention; Fig. 3 shows a double-skinned structure 301 according to another embodiment of the invention; FIG. 11 shows another embodiment of a double-skin structure 301 using sound absorbing material 340. FIG. It is a figure which shows numerical analysis object. It is a figure which shows the result of numerical analysis.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is a double-skin structure 301 used for the outer wall of a building, and the double-skin structure 301 according to the present invention is characterized in that sound insulation louvers 1 are arranged. Therefore, first, the principle of the noise reduction method adopted by the sound insulation louver 1 used in the present invention will be described. FIG. 1 is a diagram for explaining the principle of a sound insulation louver 1 used in the present invention.

FIG. 1(A) is a perspective view of a louver. The louver is constructed by arranging a plurality of louver blade members 3 continuously. Although this example shows the case where the louver blade members 3 are arranged with a predetermined space in the vertical direction, the louver blade members 3 may be arranged in the horizontal direction to form a louver.

The louver blade member 3 has two main surfaces 4 and 5, the main surface 4 (main surface 5) of one louver blade member 3 and the main surface 5 (main surface 5) of the louver blade member 3 adjacent thereto. The space between the surface 4) serves as a flow path for air, an optical path for light, or a propagation path for sound. Such a space is called a propagation path 100. FIG.

Here, FIG. 1B is a diagram showing only the inner space of the propagation path 100 as described above. When noise propagates through the propagation path 100, which is the space between the louver blade members 3, if the dimensional cross section of the propagation path 100 (the plane perpendicular to the direction of noise propagation) is less than half the wavelength of the noise, the noise propagates one-dimensionally in the space as a plane wave.

Hereinafter, in the propagation path 100 according to the embodiment of the present specification, an example in which a noise source exists on the upstream side and noise from the noise source is propagated to the downstream side will be described. Further, the explanation is given on the premise that the propagation path 100 is installed in the horizontal direction in the longitudinal direction, but the installation method of the propagation path 100 is not limited to such an example.

In the propagation path 100 of the sound insulation louver 1 used in the present invention, it is assumed that the two main surfaces 4 and 5 facing each other above and below the propagation path 100 are in an acoustically "soft" state. As shown in FIG. 1(B), when the surfaces facing each other in the propagation path 100 are acoustically "soft", that is, when the acoustic impedance ratio Z on the surface of the main surface 4 and the main surface 5 is 0, the upstream It is known that noise propagated from the side is reflected upstream and does not propagate downstream.

In this embodiment, two opposing surfaces having an acoustic impedance ratio Z of 0 on the surfaces of the main surface 4 and the main surface 5 are described based on an example in which they face each other in the vertical direction. Two opposing wall surfaces having an acoustic impedance ratio Z of 0 may be horizontally opposed.

Conventional techniques (for example, the techniques described in Japanese Patent No. 3831263 and Japanese Patent No. 5454369) are designed to reduce the length of the acoustic tube at a frequency at which the length of the acoustic tube is equal to 1/4 wavelength and at odd-numbered multiples thereof. The fact that the acoustic impedance ratio Z at the tube mouth is 0 is used.

On the other hand, the sound insulation louver 1 used in the present invention utilizes a resonator 10 in which a resonance phenomenon occurs due to a slit structure having a closed cavity behind, as shown in FIG. FIG. 2A is a perspective view of the resonator 10. FIG. FIG. 2(B) is a cross-sectional view of the slit-like opening 50 of the resonator 10 of FIG. 2(A) taken vertically along the longitudinal direction.

As shown in FIG. 2, the resonator 10 used in the sound insulation louver 1 used in the present invention is basically composed of a square prism-shaped housing 40 having a hollow inner space. One surface of the housing 40 constituting the resonator 10 has a longitudinal slit-shaped opening 50 and partition walls 60 arranged on both sides of the slit-shaped opening 50 and extending into the space inside the resonator 10. And, it is characterized by having. Here, each dimension of the resonator 10 is represented by symbols shown in FIG. 2(B). One surface of the housing 40 in which the slit-shaped opening 50 is formed and the partition wall 60 are perpendicular to each other.

If each dimension of the resonator 10 is sufficiently small with respect to the wavelength, the acoustic impedance ratio Z at the slit-shaped opening 50 can be obtained by the following equation (1).

However, f is the noise frequency, c is the speed of sound, and ρ is the medium (air) density. V _n is the volume of the space surrounded by the slit-shaped opening 50 and the partition wall 60, other than the shaded area in FIG. be done. Note that the second term in [ ] in Equation (2) is a term related to the correction of the opening edge. In addition, the hatched space in FIG. 2(B) corresponds to the air layer of the resonator 10 functioning as a resonator.

Also, V is the volume of the cavity of the resonator 10 (the volume of the air layer) and is calculated by the following equation (3).

Also, S is the area of the slit-shaped opening 50 (slit opening) and is calculated by the following equation (4).

The first term r on the right side of equation (1) is acoustic resistance such as friction generated between the surface of the partition wall 60 of the resonator 10 functioning as a resonator and the air. When the partition wall 60 is made of a material with a smooth surface such as metal, the acoustic resistance r becomes a very small value, and the acoustic impedance ratio Z at the opening of the slit-shaped opening 50 is almost 0 at the resonance frequency f that satisfies the following equation. Become.

When two resonators 10 functioning as such resonators are arranged facing each other along the upper and lower inner walls 105 of the propagation path 100 as shown in FIG. The noise of frequency f propagating from the upstream side is reflected to the upstream side and does not propagate to the downstream side. FIG. 3 is a diagram showing the sound insulation louver 1 used in the present invention, and the sound insulation louver 1 used in the present invention is viewed vertically along the longitudinal direction of the propagation path 100 (or the longitudinal direction of the slit-shaped opening 50). It is a sectional view.

According to the sound insulating louver 1 of the propagation path 100 as shown in FIG. 3, the acoustic impedance ratio at the slit-shaped openings 50 of the opposing resonators 10 is almost 0 at the resonance frequency of the resonators 10, and the incident light from the upstream side Noise is reflected upstream and does not propagate downstream.

In the sound insulating louver 1 shown in the embodiment of the present invention, the resonator 10 is provided so as to be embedded in the louver blade member 3, but this is not necessarily the case. 4 and 5 may be attached.

Further, in the sound insulation louver 1 shown in this embodiment, the louver blade members 3 constituting the sound insulation louver 1 have only one form, and the sound insulation louver 1 is constituted by arranging a plurality of louver blade members 3 of the same form. However, as long as the surfaces of the main surfaces 4 and 5 of the louver blade member 3 are made into an acoustically "soft" state by the resonator 10, it is not limited to such a mode. .

In the sound insulation louver 1 shown in this embodiment, one propagation path 100 is provided with a pair of resonators 10 facing each other. may be configured.

The sound insulation louver 1 described with reference to FIGS. 1 to 3 has a further embodiment, and for the further embodiment, refer to the description of Japanese Patent Application No. 2016-188009 by the inventor of the present application. This is incorporated herein by reference.

The present invention is configured by applying the sound insulation louver 1 as described above to the double skin structure 301 . FIG. 4 illustrates a double skin structure 301 according to an embodiment of the invention. FIG. 4(A) is a perspective view of a double skin structure 301 according to an embodiment of the present invention, and FIG. 4(B) is an enlarged cross-sectional view of the portion enclosed by the dotted line in FIG. 4(A).

The double-skin structure 301 constitutes the outer wall of the building, which is composed of an outer member 304 and an inner member 305 provided on the indoor side of the outer member 304 at a predetermined distance. A space formed between the outer member 304 and the inner member 305 is called an air layer. A vertical end of the double skin structure 301 is referred to as an open end 307 .

In summer, the air layer of the double-skin structure 301 is made to flow in air from the opening end 307 and is discharged from the upper opening (not shown), thereby alleviating the influence of solar radiation and improving the indoor temperature. improve the environment. On the other hand, however, the open end 307 becomes a sound insulation defect, and the sound insulation performance of the exterior wall having the double skin structure 301 is greatly reduced compared to the case where the open end 307 is not provided.

Therefore, in the double skin structure 301 according to the present invention, the sound insulation louver 1 as described above is provided between the outer member 304 and the inner member 305 in order to reduce noise without impeding good air permeability in the air layer. I'm trying to put it in between. In this embodiment, the sound insulation louver 1 is arranged at the open end 307 of the double skin structure 301, but the vertical height of the sound insulation louver 1 is not limited to this.

In the double skin structure 301 according to the present invention as described above, the sound insulating louver 1 provided with the resonator 10 having an acoustic impedance ratio of 0 is arranged between the outer member 304 and the inner member 305 . The sound insulating louver 1 has a function of securing the gap between the louver blade members 3 as a ventilation path and preventing noise from propagating through the ventilation path. This function prevents outdoor noise from propagating from the open end 307 of the double skin structure 301 into the air layer. As a result, according to the double skin structure 301 of the present invention, while maintaining the introduction of outside air into the air layer and the circulation of the air, the open end 307 is prevented from becoming a sound insulation defect. Sound insulation performance can be improved.

Further, according to the double-skin structure 301 of the present invention, the sound pressure level of the noise incident on the inner member 305 is reduced by preventing outdoor noise from propagating into the air layer from the open end 307 . This eliminates the need for a member with high sound insulation performance for the inner member 305, thereby realizing cost reduction. For example, it is possible to configure the inner member 305 with thin glass.

Moreover, since the sound insulation louver 1 used in the double skin structure 301 according to the present invention is a long body having the same cross section, it is easy to manufacture and install.

The louver blade member 3 constituting the sound insulating louver 1 shown in this embodiment can be manufactured by integrating the resonator 10 with the entire louver blade member 3 and extruding aluminum or the like.

Next, another example of the sound insulation louver 1 will be described. FIG. 5 shows another sound insulation louver 1 used in the present invention. In the embodiments described so far, the resonators 10 are arranged on both sides of the propagation path 100 so that the main surfaces 4 and 5 of the louver blade members 3 are acoustically "soft." I was doing

On the other hand, in the present embodiment, by arranging the resonator 10 only on one side of the propagation path 100, an attempt is made to reproduce an acoustically "soft" state. In the sound insulation louver 1 according to this embodiment, FIG. Each shows the case of "one side parallel arrangement".

According to the numerical analysis method using the two-dimensional boundary element method, it can be confirmed that the method of "opposing arrangement" of the resonators 10 is more effective as a noise reduction method than other arrangement methods. When it turns out that a sufficient noise reduction effect can be expected for layout methods such as "arrangement" and "one-side parallel arrangement", and only "one-side arrangement" and "one-side parallel arrangement" can be adopted for reasons such as layout. can also adopt such an arrangement as appropriate.

As described above, in the sound insulation louver used in the present invention, a resonator having a slit-shaped opening with an acoustic impedance ratio of 0 is arranged in the propagation path 100. According to such a sound insulation louver used in the present invention, the structure is simple, it is possible to reduce costs associated with increased man-hours for manufacturing, transportation, and construction.

Moreover, according to the sound insulation louver used in the present invention, it is possible to deal with noise from various directions and to ensure sufficient sound insulation performance.

Next, another example of the sound insulation louver 1 will be described. First, the single louver blade member 210 constituting the sound insulation louver 1 will be described. FIG. 6 shows a louver blade member 210 used in another sound insulation louver 1 used in the present invention.

The sound insulation louver 1 is constructed by arranging a plurality of louver blade members 210 at predetermined intervals. Here, in FIGS. 6 to 9, the louver blade member 210 and the sound insulation louver 1 are viewed in cross section in the longitudinal direction. Therefore, the louver blade member 210 and the sound insulation louver 1 have a length as an elongated body in the depth direction of the paper surface.

In addition, although the configuration of the louver blade member 210 is referred to as a "straight line portion", the actual shape is a plane portion.

The louver blade member 210 is preferably made of a material that is rigid and has a large sound transmission loss, such as aluminum.

The louver blade member 210 has a first straight portion 231 , a second straight portion 232 parallel to the first straight portion 231 , and a parabolic portion 240 extending from the second straight portion 232 . The parabolic portion 240 functions as a sound reflecting portion.

The first straight portion 231 and the second straight portion 232 are connected by a third straight portion 233, and the first straight portion 231, the second straight portion 232, and the third straight portion 233 surround the A reinforcing rib 260 is provided in the space.

The louver blade member 210 has an arc portion 250 extending from the first straight portion 231 via the fourth straight portion 234 . The arc portion 250 functions as a sound reflecting portion.

By arranging a plurality of the louver blade members 210 as described above at a predetermined interval so that the first straight portions 231 and the second straight portions 232 of all the louver blade members 210 are parallel, A sound insulation louver 1 is constructed.

That is, in the sound insulation louver 1 , the first linear portion 231 of one louver blade member 210 is arranged parallel to the second linear portion 232 of the other louver blade member 210 . FIG. 7 shows another sound insulation louver 1 used in the present invention.

As long as each louver blade member 210 is fixed as shown in FIG. 7, any method for fixing the louver blade member 210 may be used. Also, in the sound insulation louver 1 shown in the figure, the left side is the noise source side where equipment and the like are installed, and the right side is the sound receiving side.

By arranging a plurality of louver blade members 210 as shown in FIG. 7 , ventilation paths 215 are formed between adjacent louver blade members 210 . An opening of the ventilation path 215 on the noise source side (upstream side) is defined as a first opening 211 . Also, the opening of the ventilation path 215 on the sound receiving side (downstream side) is defined as a second opening 212 .

The structure characterizing the sound insulation louver 1 used in the present invention is described below. Firstly, it has a ventilation path (section A) composed of parallel facing wall surfaces composed of a first straight portion 231 and a second straight portion 232 .

As a second characteristic structure of the sound insulation louver 1 used in the present invention, it has a parabolic curved surface (section B) as an inner wall of the ventilation path 215 .

As a third characteristic structure of the sound insulation louver 1 used in the present invention, it has an arc curved surface (section C) as an inner wall of the ventilation path 215 .

As a fourth characteristic structure of the sound insulation louver 1 used in the present invention, the point D is the common focal point of the parabolic curved surface (section B) and the arc curved surface (section C).

As a fifth characteristic structure of the sound insulation louver 1 used in the present invention, the ventilation path 215 is configured in the order of section A, section B, and section C from the first opening 211 on the noise source side.

Next, the principle by which the sound insulation louver 1 according to the present invention reduces the noise transmitted through the ventilation path 215 will be described below. 8 and 9 show diagrams for explaining the principle of the sound insulation louver 1 according to the present invention. In the figure, arrows indicate the direction of flow of noise sound waves.

In FIG. 8, as shown in (0), noise enters the first opening 211 of the sound insulation louver 1 from various directions.

As shown in (1), the noise incident on the section A of the ventilation path 215 propagates through the section A as a plane wave at a frequency at which the width of the section A (the distance between 31 and 32) is less than half the wavelength.

Next, as shown in (2), the sound wave propagates through section A as a plane wave and is reflected by the parabolic curved surface of section B and converges toward focus D. FIG.

Next, as shown in (3), the sound wave that has passed through the focal point D is incident on the arc curved surface of the section C.

Next, as shown in (4) of FIG. 9, the sound wave reflected by the arc curved surface of section C converges toward focus D again.

Subsequently, as shown in (5), the sound wave that has passed through the focal point D is incident on the parabolic curved surface of the section B.

Next, as shown in (6), the sound wave reflected by the parabolic surface in section B propagates as a plane wave in section A and is re-radiated to the first opening 211 on the noise source side.

As described above, according to the sound insulation louver 1 used in the present invention, by reradiating the noise propagating through the ventilation path 215 of the sound insulation louver 1 toward the noise source side, the noise transmitted through the ventilation path 215 is reduced, and the sound is insulated. The sound insulation performance of the louver 1 can be improved.

In addition, according to the sound insulation louver 1 used in the present invention, the only parts required are the louver blade members 210, the number of parts can be reduced, and the structure is simple. can be reduced.

Moreover, according to the sound insulation louver 1 used in the present invention, it is possible to deal with noise from various directions and to ensure sufficient sound insulation performance.

According to the sound insulation louver 1 used in the present invention, noise transmitted through the ventilation path 215 can be reduced regardless of the noise incident angle.

Moreover, according to the sound insulation louver 1 used in the present invention, the louver wall can be constructed only by the louver blade member 210, so that the number of members can be reduced and the structure can be simplified.

In addition, the main body of the louver blade member 210 is an elongated body in the same cross-sectional view, and together with the reduction in the number of members and the simplification of the structure, the manufacturing cost and the transportation cost are reduced, and the installation is simple and efficient. Effects such as a reduction in construction costs can be expected.

The sound insulation louver 1 described with reference to FIGS. 6 to 9 has further embodiments, and for further embodiments, refer to the description of Japanese Patent Application No. 2016-188011 by the inventor of the present application. It is incorporated herein by reference.

The present invention is configured by applying the sound insulation louver 1 as described above to the double skin structure 301 . FIG. 10 illustrates a double skin structure 301 according to an embodiment of the invention. FIG. 10(A) is a perspective view of a double skin structure 301 according to an embodiment of the present invention, and FIG. 10(B) is an enlarged cross-sectional view of the portion surrounded by the dotted line in FIG. 10(A).

In the double skin structure 301 according to the present invention, the sound insulation louver 1 as described above is placed between the outer member 304 and the inner member 305 in order to reduce noise without impeding good air permeability in the air layer. I'm trying to distribute it. In this embodiment, the sound insulation louver 1 is arranged at the open end 307 of the double skin structure 301, but the vertical height of the sound insulation louver 1 is not limited to this.

In the double skin structure 301 according to the present invention as described above, a plurality of reflecting portions (240, 250) are formed in the ventilation paths 215 formed between the louver blade members 210, and the Sound incident on the first opening 211 of the ventilation path 215 is reflected by the plurality of reflecting portions (240, 250), and the sound insulation louver 1 emitted from the first opening 211 is positioned between the outer member 304 and the inner member 305. placed in between. The sound insulating louver 1 has a function of securing the gap between the louver blade members 3 as a ventilation path and preventing noise from propagating through the ventilation path. This function prevents outdoor noise from propagating from the open end 307 of the double skin structure 301 into the air layer. As a result, according to the double skin structure 301 of the present invention, while maintaining the introduction of outside air into the air layer and the circulation of the air, the open end 307 is prevented from becoming a sound insulation defect. Sound insulation performance can be improved.

Further, according to the double-skin structure 301 of the present invention, the sound pressure level of the noise incident on the inner member 305 is reduced by preventing outdoor noise from propagating into the air layer from the open end 307 . This eliminates the need for a member with high sound insulation performance for the inner member 305, thereby realizing cost reduction. For example, it is possible to configure the inner member 305 with thin glass.

Moreover, since the sound insulation louver 1 used in the double skin structure 301 according to the present invention is a long body having the same cross section, it is easy to manufacture and install.

Here, in the sound insulation louver 1 described above, the sound wave incident on the first opening 211 is turned into a plane wave in the section A, which is reflected by the parabolic curved surface of the section B formed by the parabolic portion 240. After passing through, it is converged again toward the focus D on the arc curved surface of the section C formed by the arc portion 250, and further reflected by the parabolic curved surface of the section B formed by the parabolic portion 240, and the section A is made into a plane wave. Although the sound is propagated and emitted to the first opening 211 on the noise source side, the embodiment of the sound insulation louver 1 used in the present invention is not limited to this.

The sound insulation louver 1 used in the present invention converts an incident sound wave from the first opening 211 of the sound insulation louver 1 into a plane wave, reflects the plane wave from a plurality of reflecting portions in the ventilation path 215, and re-enters the noise source from the first opening 211. As long as the configuration is such that the light is emitted to the side, the reflecting portion is not limited to the reflecting portion formed of the parabolic curved surface, the arc curved surface, or the like described in the embodiment.

That is, the sound insulation louver 1 used in the present invention has a characteristic shape in the ventilation path 215 so that the sound wave incident from the first opening 211 of the sound insulation louver 1 is emitted from the first opening 211 again. It includes all thoughts.

In addition, the sound insulation louver 1 used in the present invention forms a focal point of sound waves in the ventilation path 215 by giving a feature to the shape of the ventilation path 215, and utilizes this focus to achieve sound insulation. is also included. Although there is a disadvantage that the number of parts increases, for example, placing a sound absorbing material at the focus D in the embodiment to absorb sound at the focus D is also included in the sound insulation louver 1 used in the present invention. .

Next, another embodiment of the present invention will be described. FIG. 11 illustrates a double skin structure 301 according to another embodiment of the invention. FIG. 11(A) is a perspective view of a double skin structure 301 according to another embodiment of the present invention, and FIG. 11(B) is an enlarged cross-sectional view of the portion surrounded by the dotted line in FIG. 11(A). 12A and 12B are diagrams schematically illustrating noise transmission with or without the sound insulation plate 330. FIG. 12A shows a double-skin structure without the sound insulation plate 330, and FIG. 12B shows the sound insulation plate 330. A double skin structure 301 is shown according to an embodiment of the present invention.

In another embodiment of the double skin structure 301 of the present invention, a sound insulating plate 330 having a major surface perpendicular to the major surface of the inner member 305 is attached to the inner member 305 at the open end 307. . The sound insulating plate 330 may be attached to both the inner member 305 and the outer member 304 . Here, the sound insulation plate 330 used in the double skin structure 301 according to another embodiment has sufficient sound insulation performance (sound transmission loss) with respect to frequency components of noise to be reduced.

In this embodiment, the sound insulating plate 330 having a main surface perpendicular to the main surface of the inner member 305 is attached to the inner member 305. However, the sound insulating plate 330 is attached to the inner member 305. The mode of attachment is not limited to this.

In the embodiment shown in FIG. 11, a sound insulating plate 330 is installed below the open end 307 after securing a space so as not to hinder the introduction of outside air into the air layer.

The sound insulating plate 330 is installed so that its tip is positioned outside the line connecting the noise source and the lower end of the outer member 304, which is indicated by a dashed line with an arrow in the drawing. By installing the sound insulating plate 330 in this way, it is possible to prevent the noise from propagating directly into the air layer. Noise propagating from the open end 307 into the air layer is attenuated by diffraction at the tip of the sound insulating plate.

As shown in FIG. 12A, without the sound insulating plate 330, noise propagates into the air layer through the open end 307 after being reflected by the inner member 305 or directly from the noise source. On the other hand, when the sound insulation plate 330 is installed as described above, as shown in FIG. It propagates through the open end 307 into the air layer.

In the embodiment shown in FIG. 11, the main surface of the sound insulating plate 330 is horizontally installed, but the main surface of the sound insulating plate 330 does not necessarily have to be horizontal.

Next, another embodiment of the present invention will be described. FIG. 13 is a diagram illustrating the sound insulation plate 330 provided with the standing portion 335. As shown in FIG. Also, FIG. 14 illustrates a double-skin structure 301 according to another embodiment of the present invention. FIG. 14(A) is a perspective view of a double skin structure 301 according to another embodiment of the present invention, and FIG. 14(B) is an enlarged cross-sectional view of the portion surrounded by the dotted line in FIG. 14(A).

When the incident angle of noise is shallow because the noise source is far away, the noise insulation plate 330 can be extended while maintaining the noise reduction effect by installing the sound insulation plate 330 having the standing portion 335 raised upward. can be minimized (see FIG. 13(A)).

When the sound insulating plate 330 is installed so that the tip of the raised standing portion 335 is positioned at the same height as the lower end of the inner member 305, at least the noise incident on the opening end portion 307 from the depression angle direction (below) is Propagation directly into the air layer can be prevented. Such a sound insulating plate 330 is effective when the noise source cannot be specified or when the incident angle of the noise is unclear (see FIG. 13B).

In the double-skin structure 301 shown in FIG. 14, the sound insulation plate 330 is installed so that the tip of the erected standing portion 335 is positioned above the lower end of the inner member 305. Such a sound insulation plate By using 330, it is possible to more reliably prevent noise incident on the open end 307 from the depression angle direction (below) from propagating directly into the air layer.

Next, another embodiment of the present invention will be described. The sound insulation plate 330 can also be installed in the air layer of the double skin structure 301 . FIG. 15 is a diagram showing such an embodiment. FIG. 15(A) is a perspective view of a double skin structure 301 according to another embodiment of the present invention, and FIG. 15(B) is an enlarged cross-sectional view of the portion surrounded by the dotted line in FIG. 15(A). FIG. 16 is a diagram showing a double-skin structure 301 according to another embodiment using a sound absorbing material 340. As shown in FIG.

As shown in FIG. 15, in the present embodiment, two sound insulating plates 330 are alternately arranged when viewed from the vertical direction, and are installed so that the ventilation paths form a labyrinth, thereby preventing noise from propagating in the air layer. to prevent In this embodiment, one sound insulating plate 330 is attached to the outer member 304 and one sound insulating plate 330 is attached to the inner member 305 .

In the embodiment shown in FIG. 15, an example using two sound insulating plates 330 is shown, but a larger number of sound insulating plates 330 may be alternately arranged.

A higher noise reduction effect can be obtained by applying a sound absorbing treatment to the surface of the sound insulating plate 330 that constitutes the labyrinthine ventilation path. FIG. 16A shows an example in which a sound absorbing material 340 is attached to the lower portion of one sound insulating plate 330 provided on the outer member 304 .

It is more effective to install the sound insulating plate 330 at a position as close to the open end 307 as possible in the air layer. However, the above does not deny the installation of the sound insulating plate 330 at a position away from the open end 307 . FIG. 16(B) shows an example in which the sound insulating plate 330 is installed in multiple stages and the sound absorbing material 340 is attached to the lower portion of the sound insulating plate 330 . In the example shown in FIG. 16(B), the sound insulating plate 330 is also arranged at a position away from the open end 307, and such an arrangement can more reliably prevent the propagation of noise. .

A plurality of open ends 307 for introducing outside air into the air layer in the double-skin structure 301 are generally provided in order to ensure air circulation within the air layer. The sound insulation plate 330 according to the present invention is effectively placed at or near the open end 307 near the inner noise source. For example, when road traffic noise on the ground is considered as a noise source, it is placed near the open end 307 on the second floor and above. However, this does not negate the effectiveness of arranging the sound insulating plate 330 near the open end 307 far from the noise source.

In the embodiments described so far, it is assumed that the noise source is located below the open end 307 and that the open end 307 is provided on the upper and lower sides of the double skin structure 301 (see FIG. 1). ), the invention, particularly the embodiment shown in FIGS. 15 and 16, is also effective for double-skin structures 301 with open ends 307 on the sides.

According to the double skin structure 301 according to the present embodiment as described above, the sound insulating plate 330 can prevent noise from propagating from the open end 307 into the air layer. Moreover, the double-skin structure 301 according to the present embodiment can prevent the opening end 307 from becoming defective in sound insulation, and can improve the sound-insulating performance of the double-skin structure 301 . At this time, the introduction of outside air into the air layer and the circulation of the air can be maintained.

In addition, in the double skin structure 301 according to this embodiment, the sound insulating plate 330 can be configured as an elongated body having the same cross section, which facilitates manufacturing and mounting.

Further, according to the double skin structure 301 according to the present embodiment, the sound pressure level of the noise incident on the inner member 305 is lowered by preventing outdoor noise from propagating from the open end 307 into the air layer. . This eliminates the need for a member with high sound insulation performance for the inner member 305, thereby realizing cost reduction. For example, it is possible to configure the inner member 305 with thin glass.

In addition, in the double skin structure 301 according to the present embodiment, since the noise reduction effect is obtained by the diffraction attenuation of the sound insulating plate 330, compared with the countermeasure method using a resonator (for example, see Japanese Patent Application No. 2016-188010), Low frequency dependence. For this reason, it is also effective for outdoor noise with a wide range of frequency components such as traffic noise.

In addition, the sound insulating plate 330 in the double skin structure 301 according to this embodiment also has a function as a canopy that blocks solar radiation from above for the lower floors. As a result, the sound environment in the building can be improved, the thermal environment can be improved, and the heat load of the building can be reduced, thereby reducing the energy consumption of the building as a whole.

The noise reduction effect of the double-skin structure 301 according to the present invention was verified by numerical analysis, and the results are shown below. FIG. 17 is a diagram showing an object of numerical analysis.

A two-dimensional boundary element method was used for the numerical analysis. FIG. 17A shows a basic double-skin structure 301 in which the sound insulating plate 330 is not provided and the distance between the inner member 305 and the outer member 304 is 600 mm.

In the numerical analysis, as shown in FIG. 17(A), a sound wave was incident from a depression angle of 45 degrees, and the acoustic energy passing through the virtual plane indicated by the dashed line in the drawing was obtained by calculation.

With the basic shape without the sound insulation plate 330 shown in FIG. 17(C) in which the sound insulating plate 330 and the sound absorbing material 340 are arranged (hereinafter referred to as the “sound insulating plate C” condition), the amount of reduction in the acoustic energy passing upward through the virtual plane, that is, the noise due to the sound insulating plate A reduction effect was sought. 17(B) corresponds to the embodiment shown in FIG. 11, and FIG. 17(C) is similar to the embodiment shown in FIG.

“Sound insulating plate B” shown in FIG. 17B is a condition in which the sound insulating plate 330 is installed 600 mm below the lower end of the outer member 304 . The width of the sound insulating plate 330 is set to 1300 mm, which prevents sound waves incident from a depression angle of 45 degrees from propagating directly into the air layer through the opening.

“Sound insulating plate C” shown in FIG. 17C is a condition in which the sound insulating plates 330 are alternately arranged in the air layer of the double skin structure 301 . The staggered sound barriers 330 provide a labyrinthine vent path between the inner member 305 and the outer member 304 . A sound absorbing material 340 is arranged on the lower surface of the upper sound insulating plate 330, which constitutes the labyrinthine ventilation path, as shown. It was assumed that glass wool having a thickness of 50 mm was installed as the sound absorbing material 340 .

FIG. 18 shows the results of numerical analysis under the above conditions. FIG. 18 shows the frequency characteristics of the effect of the sound insulating plate and the sound absorbing material in “sound insulating plate B” and “sound insulating plate C” based on the basic shape.

A positive noise reduction effect is obtained for both the sound insulating plate B and the sound insulating plate C, and it can be confirmed that the installation of the sound insulating plate 330 can reduce the noise propagating in the air layer. Moreover, it can be confirmed that the noise reduction effect is obtained over a wide frequency range for both the sound insulation plate B from 63 Hz to 4 kHz and the sound insulation plate C from 250 Hz to 4 kHz.

From the above results, the method of arranging the sound insulating plate 330 proposed in the present invention reduces the noise propagating in the air layer between the inner member 305 and the outer member 304 of the double skin structure 301, and the double skin structure 301 as a whole It was confirmed that it is effective as a method for improving the sound insulation performance.

Reference Signs List 1 Sound insulating louver 3 Louver blade members 4, 5 Principal surface 10 Resonator 11 First section 12 Second section 13 Third section 14 Fourth section 20 Outer shell member 25 Opening surface 30 L-shaped member 35 Partition plate member 40 Housing 50 Slit opening 60 Partition wall portion 70 Partition plate member 100 Propagation path 210 Louver blade member 211 First opening 212 Second opening 215 Ventilation path 231 First straight portion 232... Second straight line portion 233... Third straight line portion 234... Fourth straight line portion 240... Parabolic portion (reflection portion)
250 Arc part (reflection part)
260 Reinforcement rib 301 Double skin structure 304 Outer member 305 Inner member 307 Open end 330 Sound insulating plate 333 Plane portion 335 Standing Part 340... Sound absorbing material D... Focus

Claims (3)

A double-skin structure that constitutes an outer wall of a building, comprising an outer member and an inner member provided on the indoor side of the outer member at a predetermined distance,
a sound insulating plate attached to the inner member ;
A double-skin structure , wherein the sound insulating plate is installed so that the tip thereof is positioned outside a line connecting the noise source and the lower end of the outer member. A double-skin structure that constitutes an outer wall of a building, comprising an outer member and an inner member provided on the indoor side of the outer member at a predetermined distance,
A double-skin structure, wherein sound insulation plates are attached to said outer member and said inner member in a staggered manner. 3. The double-skin structure of claim 2, wherein a sound absorbing material is provided on the lower surface of the sound insulating plate.

Images