JP7042629B2 - Double skin structure - Google Patents

Description

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

One of the exterior walls used to enhance the heat insulation performance of a building is known to have a double-skin structure. In such a double skin structure, a space (ventilation space) is provided between the outer member (outer skin) and the inner member (inner skin). In summer, in order to prevent the temperature rise in this space, an opening is provided between the outer skin and the inner skin, or 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 Unexamined Patent Publication No. 2013-181333) has a double-skin structure composed of a frame-shaped PC unit, which is projected from the left and right front of the frame of the PC unit to block sunlight from the left and right. The sleeve wall for the purpose, the outer sash that is driven into the sleeve wall and can install the outer surface material, the inner sash that is arranged facing the outer sash via the hollow layer and can install the inner side surface material, and the sleeve. Disclosed is a double-skin structure provided on a wall, provided with a communication port for communicating the outside and the hollow layer, and having a stepped portion formed on the outside of at least one side surface of the sleeve wall.
Japanese Unexamined Patent Publication No. 2013-181333

In the exterior wall having a double skin structure, it is possible to contribute to temperature control in the building by ventilating from the opening end in the ventilation space between the outer member (outer skin) and the inner member (inner skin). It will be possible. However, on the other hand, there is a problem that the end of the opening is lacking in sound insulation, and the sound insulation performance of the exterior wall having a double-skin structure is significantly deteriorated as compared with the case where there is no end of the opening.

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

Therefore, in the exterior wall having a double-skin structure, the inner member (inner) in the upper floor is compared with the case of the single-skin exterior wall due to the influence of noise propagating two-dimensionally from the opening end of the lower floor to the ventilation space. There is also a problem that the sound pressure level of external noise incident on the skin) becomes high, and a member having higher sound insulation performance may be required, which is costly.

So far, no proposal has been made to solve the above-mentioned problems such as deterioration of sound insulation performance in the double-skin structure, which has been a problem.

The present invention solves the above-mentioned problems, and the double-skin structure according to the present invention is an outer wall of a building composed of an outer member and an inner member provided on the indoor side of the outer member at a predetermined distance. A resonance having a double-skin structure constituting the portion, in which a plurality of louver blade members are continuously arranged and a sound insulating louver is arranged between the outer member and the inner member and has a slit-shaped opening. The vessel is characterized in that it is arranged on the louver blade member.

Further, the double-skin structure according to the present invention is characterized in that a resonator is arranged on each of the two main surfaces of the louver blade member.

Further, the double-skin structure according to the present invention is characterized in that the slit-shaped openings of the resonators of the adjacent louver blade members are arranged so as to face each other.

Further, the double-skin structure according to the present invention is a double-skin structure constituting an outer wall portion of a building composed of an outer member, an inner member provided on the indoor side of the outer member at a predetermined interval, and a louver. A sound insulating louver in which a plurality of blade members are continuously arranged is arranged between the outer member and the inner member, and a plurality of sound insulating louvers are formed in the ventilation path formed between the louver blade members. It is characterized in that the reflecting portion is formed and the sound incident on the first opening of the ventilation path is reflected by the plurality of reflecting portions and emitted from the first opening.

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

Further, according to the double skin structure according to the present invention, the sound pressure level of the noise incident on the inner member (inner skin) is lowered by preventing the outdoor noise from propagating from the end of the opening into the air layer. .. As a result, the inner member (inner skin) does not require a member having high sound insulation performance, and cost reduction can be realized. For example, it becomes possible to construct an inner member (inner skin) with thin glass.

Further, since the sound insulation louver and the sound insulation plate used in the double skin structure according to the present invention are long 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 in this invention. It is a figure explaining the resonator 10 used for the sound insulation louver 1 used in this invention. It is a figure which shows the sound insulation louver 1 used in this invention. It is a figure which shows the double skin structure 301 which concerns on embodiment of this invention. It is a figure which shows the other sound insulation louver 1 used in this invention. It is a figure which shows the louver blade member 210 used for another sound insulation louver 1 used in this invention. It is a figure which shows the other sound insulation louver 1 used in this invention. It is a figure explaining the principle of another sound insulation louver 1 used in this invention. It is a figure explaining the principle of another sound insulation louver 1 used in this invention. It is a figure which shows the double skin structure 301 which concerns on other embodiment of this invention. It is a figure which shows the double skin structure 301 which concerns on other embodiment of this invention. It is a figure which simplified the noise transmission by the presence or absence of a sound insulation plate 330. It is a figure explaining the sound insulation plate 330 provided with the erection part 335. It is a figure which shows the double skin structure 301 which concerns on other embodiment of this invention. It is a figure which shows the double skin structure 301 which concerns on other embodiment of this invention. It is a figure which shows the double skin structure 301 which concerns on other embodiment using a sound absorbing material 340. It is a figure which shows the numerical analysis target. It is a figure which shows the result of the numerical analysis.

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 an outer wall of a building, and the double-skin structure 301 according to the present invention is characterized in that a sound insulation louver 1 is 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 illustrating the principle of the sound insulation louver 1 used in the present invention.

FIG. 1A is a perspective view of a louver. The louver is configured by continuously arranging a plurality of louver blade members 3. This example shows a case where the louver blade members 3 are arranged with a predetermined space in the vertical direction, but the louver blade members 3 may be arranged horizontally to form a louver.

The louver blade member 3 has two main surfaces 4 and a main surface 5, and 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 to the main surface 4 (main surface 5). The space between the surface 4) becomes an air flow path, an optical path, or a sound propagation path. Such a space will be referred to as a propagation path 100.

Here, FIG. 1B is a diagram showing only the inner space in 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, when the dimensional cross section (plane perpendicular to the noise propagation direction) of the propagation path 100 is less than half of 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 in the present specification, a noise source exists on the upstream side, and noise from the noise source is propagated to the downstream side as an example. Further, although the description will be made on the premise that the longitudinal direction of the propagation path 100 is installed in the horizontal direction, 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 surfaces of the main surface 4 and the main surface 5 is 0, it is upstream. It is known that noise propagating from the side is reflected to the upstream side and does not propagate to the downstream side.

In this embodiment, the description is based on an example in which two facing surfaces having an acoustic impedance ratio Z of 0 on the surfaces of the main surface 4 and the main surface 5 face each other in the vertical direction. Two facing wall surfaces having an acoustic impedance ratio Z of 0 may face each other in the horizontal direction.

The conventional techniques (for example, the techniques described in Japanese Patent No. 3831263 and Japanese Patent No. 5454369) are such that the length of the acoustic tube is equal to 1/4 wavelength and the frequency is an odd multiple of the wavelength. It utilizes the fact that the acoustic impedance ratio Z at the tube opening becomes 0.

On the other hand, in the sound insulation louver 1 used in the present invention, as shown in FIG. 2, a resonator 10 in which a resonance phenomenon occurs due to a slit structure having a cavity sealed behind is used. FIG. 2A is a perspective view of the resonator 10. Further, FIG. 2 (B) is a cross-sectional view of the slit-shaped opening 50 of the resonator 10 of FIG. 2 (A) as viewed by cutting vertically in 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 columnar housing 40 having a hollow inner space. On one surface of the housing 40 constituting the resonator 10, a longitudinal slit-shaped opening 50 and a partition wall portion 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 a symbol shown in FIG. 2 (B). It should be noted that one surface of the housing 40 in which the slit-shaped opening 50 is formed and the partition wall portion 60 are orthogonal to each other.

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

However, f is the frequency of noise, c is the speed of sound, and ρ is the medium (air) density. Further, V _n is the volume of the space other than the shaded portion in FIG. 2B surrounded by the slit-shaped opening 50 and the partition wall 60, and is calculated by the following equation (2) in consideration of the opening end correction. Will be done. The second term in [] in the equation (2) is a term related to open end correction. Further, in FIG. 2B, the space in the shaded area corresponds to the air layer of the resonator 10 functioning as the resonator.

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

Further, 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 the equation (1) is an 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 having a smooth surface such as metal, the acoustic resistance r becomes an extremely 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 satisfying the following equation. Become.

When two resonators 10 functioning as such resonators are arranged to face each other along the upper and lower inner walls 105 of the propagation path 100 as shown in FIG. 3, the facing slit portions acoustically occur at the above frequency f. In a "soft" state, the noise of frequency f propagated 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 by cutting the longitudinal direction of the propagation path 100 (or the longitudinal direction of the slit-shaped opening 50) vertically. It is a cross-sectional view.

According to the sound insulation louver 1 of the propagation path 100 as shown in FIG. 3, at the resonance frequency of the resonator 10, the acoustic impedance ratio in the slit-shaped opening 50 of the opposed resonator 10 becomes almost 0, and the sound is incident from the upstream side. The noise is reflected to the upstream side and does not propagate to the downstream side.

In the sound insulation 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 it is not always necessary to do so, and the resonator 10 is a main surface. It may be attached to 4 or 5.

Further, in the sound insulation louver 1 shown in the present embodiment, there is only one type of louver blade member 3 constituting the sound insulation louver 1, and the sound insulation louver 1 is configured by arranging a plurality of louver blade members 3 having the same embodiment. However, as long as the surfaces of the main surfaces 4 and 5 of the louver blade member 3 are acoustically "soft" by the resonator 10, the present invention is not limited to such an embodiment. ..

In the sound insulation louver 1 shown in the present embodiment, a pair of resonators 10 facing each other are provided in one propagation path 100, but for example, two or more resonators 10 are provided in the propagation path 100. It may be configured.

The sound insulation louver 1 described with reference to FIGS. 1 to 3 has a further embodiment, and for further embodiments, the present invention can be referred to by referring to the description of Japanese Patent Application No. 2016-18809 by the inventor of the present application. It is incorporated in the specification.

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

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

In the summer, air is allowed to flow into the air layer of such a double-skin structure 301 from the opening end 307 and discharged from the upper opening (not shown) to mitigate the influence of solar radiation or to heat the room. Improve the environment. However, on the other hand, the end portion 307 has a sound insulation defect, and the sound insulation performance of the exterior wall having the double skin structure 301 is significantly deteriorated as compared with the case where the end portion 307 is absent.

Therefore, in the double-skin structure 301 according to the present invention, in order to reduce noise without impairing good air permeability in the air layer, the sound insulation louver 1 as described above is provided with the outer member 304 and the inner member 305. I try to arrange it in between. In the present embodiment, the sound insulation louver 1 is arranged at the opening end portion 307 of the double skin structure 301, but the height in the vertical direction in which the sound insulation louver 1 is provided is not limited to this.

In the double-skin structure 301 according to the present invention as described above, the sound insulation 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 insulation louver 1 has a function of securing a 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 into the air layer from the open end 307 of the double skin structure 301. As a result, according to the double-skin structure 301 according to the present invention, while maintaining the introduction of outside air into the air layer and the flow of air, the opening end portion 307 is prevented from becoming a sound insulation defect, and the double-skin structure 301 Sound insulation performance can be improved.

Further, according to the double-skin structure 301 according to the present invention, the sound pressure level of the noise incident on the inner member 305 is lowered by preventing the outdoor noise from propagating from the opening end portion 307 into the air layer. As a result, the inner member 305 does not require a member having high sound insulation performance, and cost reduction can be realized. For example, it becomes possible to construct the inner member 305 with thin glass.

Further, 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 insulation louver 1 shown in the present embodiment can be manufactured by integrating the resonator 10 with the entire louver blade member 3 and extruding it with aluminum or the like.

Next, another example of the sound insulation louver 1 will be described. FIG. 5 is a diagram showing another sound insulation louver 1 used in the present invention. In the embodiments described so far, the resonators 10 are arranged to face each other on both sides of the propagation path 100 so that the surfaces of the main surfaces 4 and 5 of the louver blade member 3 are acoustically "soft". I was doing it.

On the other hand, in the present embodiment, an attempt is made to reproduce an acoustically "soft" state by arranging the resonator 10 only on one side of the propagation path 100. In the sound insulation louver 1 according to the present embodiment, FIG. 5A shows the case where the resonator 10 is “one-sided” in the propagation path 100, and FIG. 5B shows the resonator 10 in the propagation path 100. The cases of "one-sided parallel arrangement" are shown respectively.

According to the numerical analysis method using the two-dimensional boundary element method, it can be confirmed that the method of "opposing" the resonators 10 is more effective as a noise reduction method as compared with other arrangement methods, but "one side". When it is found that sufficient noise reduction effect can be expected for arrangement methods such as "arrangement" and "one-sided parallel arrangement", and only "one-sided arrangement" and "one-sided parallel arrangement" can be adopted due to layout and other reasons. It is also possible to appropriately adopt such an arrangement.

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

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

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

The sound insulation louver 1 is configured 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 insulating louver 1 are viewed in cross section with respect to the longitudinal direction. Therefore, the louver blade member 210 and the sound insulating louver 1 have a length as a long body in the depth direction of the paper surface.

Further, the structure of the louver blade member 210 is referred to as a "straight line portion" or the like, but the actual shape is a flat surface portion.

The louver blade member 210 is preferably made of a material having rigidity and a large acoustic transmission loss, and for example, aluminum or the like can be used.

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

The first straight line portion 231 and the second straight line portion 232 are connected by the third straight line portion 233, and are surrounded by the first straight line portion 231, the second straight line portion 232, and the third straight line portion 233. Reinforcing ribs 260 are provided in the space.

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

A plurality of louver blade members 210 as described above are arranged at predetermined intervals so that the first straight line portion 231 and the second straight line portion 232 of all the louver blade members 210 are parallel to each other. The sound insulation louver 1 is configured.

That is, in the sound insulation louver 1, the first straight line portion 231 of one louver blade member 210 is arranged so as to be parallel to the second straight line portion 232 of the other louver blade member 210. FIG. 7 is a diagram showing another sound insulation louver 1 used in the present invention.

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

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

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

Further, as the second characteristic structure of the sound insulation louver 1 used in the present invention, the parabolic curved surface (section B) is provided as the inner wall of the ventilation path 215.

Further, as the third characteristic structure of the sound insulation louver 1 used in the present invention, the arc curved surface (section C) is provided as the inner wall of the ventilation path 215.

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

Further, 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 that the sound insulation louver 1 according to the present invention reduces the noise transmitted through the ventilation path 215 will be described below. Further, FIGS. 8 and 9 show diagrams illustrating the principle of the sound insulation louver 1 according to the present invention. In the figure, the arrows indicate the direction of the sound wave flow of noise.

In FIG. 8, as shown in (0), noise is incident on 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 in the section A as a plane wave at a frequency in which the width of the section A (distance between 31 and 32) is half a wavelength or less.

Next, as shown in (2), the sound wave propagating in the section A as a plane wave and reflected by the parabolic surface of the section B converges toward the focal point D.

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 FIG. 9 (4), the sound wave reflected by the arc curved surface of the section C converges toward the focal point 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 curved surface of the section B propagates in the section A as a plane wave 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, the noise propagating in the ventilation path 215 of the sound insulation louver 1 is re-radiated to the noise source side to reduce the noise transmitted through the ventilation path 215 and to insulate the sound. The sound insulation performance of the louver 1 can be improved.

Further, according to the sound insulation louver 1 used in the present invention, only the louver blade member 210 is required, the number of parts can be suppressed, and the structure is simple, so that the cost associated with the increase in manufacturing, transportation, and construction man-hours is required. Can be reduced.

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

According to the sound insulation louver 1 used in the present invention, it is possible to reduce the noise transmitted through the ventilation path 215 regardless of the noise incident angle.

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

Further, the main body of the louver blade member 210 is a long body having the same cross-sectional view, and in addition to the above-mentioned reduction in the number of member points and simplification of the structure, the manufacturing cost is reduced, the transportation cost is reduced, and the installation is simple and efficient. Therefore, the effect of reducing the construction cost can be expected.

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

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

In the double-skin structure 301 according to the present invention, in order to reduce noise without impairing good air permeability in the air layer, the sound insulation louver 1 as described above is placed between the outer member 304 and the inner member 305. I try to arrange it. In the present embodiment, the sound insulation louver 1 is arranged at the opening end portion 307 of the double skin structure 301, but the height in the vertical direction in which the sound insulation louver 1 is provided is not limited to this.

In the double-skin structure 301 according to the present invention as described above, a plurality of reflective portions (240, 250) are formed in the ventilation path 215 formed between the louver blade members 210, and the above-mentioned 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 insulating louver 1 emitted from the first opening 211 is the outer member 304 and the inner member 305. Arranged in between. The sound insulation louver 1 has a function of securing a 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 into the air layer from the open end 307 of the double skin structure 301. As a result, according to the double-skin structure 301 according to the present invention, while maintaining the introduction of outside air into the air layer and the flow of air, the opening end portion 307 is prevented from becoming a sound insulation defect, and the double-skin structure 301 Sound insulation performance can be improved.

Further, according to the double-skin structure 301 according to the present invention, the sound pressure level of the noise incident on the inner member 305 is lowered by preventing the outdoor noise from propagating from the opening end portion 307 into the air layer. As a result, the inner member 305 does not require a member having high sound insulation performance, and cost reduction can be realized. For example, it becomes possible to construct the inner member 305 with thin glass.

Further, 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 used as a plane wave in the section A, and this is reflected by the parabolic curved surface of the section B composed of the parabolic portion 240, and the focal point D is once set. After passing through, it is converged again toward the focal point D by the arc curved surface of the section C composed of the arc portion 250, and further reflected by the parabolic curved surface of the section B composed of the parabolic portion 240 to make the section A a plane wave. Although it is configured to propagate and emit light 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.

In the sound insulation louver 1 used in the present invention, the sound wave incident from the first opening 211 of the sound insulation louver 1 is converted into a plane wave, which is reflected by a plurality of reflecting portions in the ventilation path 215, and is again a noise source from the first opening 211. If the configuration is such that the light is emitted to the side, the present invention is not limited to the reflecting portion including the radial curved surface or the arc curved surface described in the embodiment.

That is, the sound insulation louver 1 used in the present invention has a technique of emitting sound waves incident from the first opening 211 of the sound insulation louver 1 again from the first opening 211 by giving a feature to the shape in the ventilation path 215. It includes all ideas.

Further, the sound insulation louver 1 used in the present invention has a technical idea that a focal point of a sound wave is formed in the ventilation path 215 by giving a feature to the shape in the ventilation path 215, and sound insulation is achieved by utilizing this focal point. Also includes. Although there is a demerit that the number of parts increases, for example, arranging a sound absorbing material at the focal point D in the embodiment to absorb sound at the focal point D is also included in the sound insulating louver 1 used in the present invention. ..

Next, another embodiment of the present invention will be described. FIG. 11 is a diagram showing a double-skin structure 301 according to another embodiment of the present invention. 11 (A) is a perspective view of the double-skin structure 301 according to another embodiment of the present invention, and FIG. 11 (B) is an enlarged cross-sectional view of a portion surrounded by a dotted line in FIG. 11 (A). Further, FIG. 12 is a diagram schematically showing noise transmission depending on the presence or absence of 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. The double skin structure 301 which concerns on embodiment of this invention is shown.

In the double skin structure 301 according to another embodiment of the present invention, a 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 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, as the sound insulation plate 330 used in the double-skin structure 301 according to another embodiment, one having sufficient sound insulation performance (acoustic transmission loss) with respect to the frequency component of the noise to be reduced is used.

In this embodiment, the sound insulating plate 330 having a main surface perpendicular to the main surface of the inner member 305 will be described based on the configuration of attaching the sound insulating plate 330 to the inner member 305. The mounting mode is not limited to this.

In the embodiment shown in FIG. 11, the sound insulating plate 330 is installed below the opening end 307 after ensuring an interval so as not to hinder the introduction of outside air into the air layer.

The sound insulation plate 330 is installed so that the tip is located outside the line connecting the noise source and the lower end of the outer member 304, which is indicated by the broken line with an arrow in the drawing. By installing the sound insulation plate 330 in this way, it is possible to prevent noise from propagating directly into the air layer. The noise propagating from the end of the opening 307 into the air layer is attenuated by diffracting the tip of the sound insulating plate.

As shown in FIG. 12A, in the absence of the sound insulation plate 330, noise is reflected directly from the noise source or by the inner member 305 and then propagates into the air layer through the open end 307. On the other hand, when the sound insulation plate 330 is installed as described above, as shown in FIG. 12B, the noise propagation path is shielded by the sound insulation plate 330, and the noise after diffraction attenuation at the tip of the sound insulation plate 330 is generated. It propagates into the air layer through the end of the opening 307.

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

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

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

When the sound insulation plate 330 is installed so that the tip of the raised upright portion 335 is located at the same height as the lower end of the inner member 305, at least the noise incident from the depression angle direction (downward) with respect to the open end portion 307 is It is possible to prevent it from propagating directly into the air layer. Such a sound insulating plate 330 is effective when the noise source cannot be specified or when the incident angle of the noise is not clear (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 raised upright portion 335 is located above the lower end of the inner member 305. Such a sound insulation plate By using the 330, it is possible to more reliably prevent the noise incident from the depression angle direction (below) with respect to the opening end portion 307 from directly propagating into the air layer.

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

As shown in FIG. 15, in the present embodiment, noise propagates in the air layer by installing the two sound insulation plates 330 alternately and in a maze-like manner when viewed from the vertical direction. To prevent. In the present 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 in which two sound insulation plates 330 are used is shown, but a larger number of sound insulation plates 330 may be arranged alternately.

A higher noise reduction effect can be obtained by performing sound absorption treatment on the surface of the sound insulating plate 330 that constitutes the maze-shaped ventilation path. FIG. 16A shows an example in which the 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 in the air layer as close to the opening end 307 as possible. However, the above does not deny that the sound insulating plate 330 is installed at a position away from the opening end portion 307. FIG. 16B 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. 16B, the sound insulating plate 330 is also arranged at a position away from the opening end portion 307, but such an arrangement can more reliably prevent the propagation of noise. ..

A plurality of open end portions 307 for introducing outside air into the air layer in the double skin structure 301 are generally provided in order to secure the flow of air in the air layer. It is effective to arrange the sound insulating plate 330 according to the present invention at or near the opening end 307 near the noise source. For example, when considering road traffic noise on the ground as a noise source, it is arranged near the lower opening end 307 on the second floor and above. However, this does not deny the effectiveness of arranging the sound insulating plate 330 near the opening end 307 far from the noise source.

In the embodiments described so far, it is assumed that the noise source is located below the opening end portion 307, and the opening end portion 307 is provided on the upper and lower sides of the double skin structure 301 (see FIG. 1). ), In particular, in the embodiment shown in FIGS. 15 and 16, it is also effective for the double skin structure 301 in which the opening end portion 307 is provided on the side surface.

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. Further, the double-skin structure 301 according to the present embodiment can prevent the opening end portion 307 from having a sound insulation defect, and can improve the sound insulation performance of the double-skin structure 301. Further, at this time, the introduction of outside air into the air layer and the flow of air can be maintained.

Further, in the double skin structure 301 according to the present embodiment, the sound insulating plate 330 can be configured as a long body having the same cross section, and is easy to manufacture and install.

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 the outdoor noise from propagating from the end portion 307 into the air layer. .. As a result, the inner member 305 does not require a member having high sound insulation performance, and cost reduction can be realized. For example, it becomes possible to construct the inner member 305 with thin glass.

Further, in the double-skin structure 301 according to the present embodiment, in order to obtain a noise reduction effect by the diffraction attenuation of the sound insulating plate 330, a countermeasure method using a resonator (see, for example, Japanese Patent Application No. 2016-188010) is compared with the countermeasure method. There is little frequency dependence. Therefore, it is also effective for outdoor noise having a wide range of frequency components such as traffic noise.

Further, the sound insulating plate 330 in the double-skin structure 301 according to the present embodiment also has a function as an eaves for blocking sunlight from above for the floors below it. As a result, the energy consumption of the entire building can be reduced by improving the sound environment in the building, improving the thermal environment, and reducing the heat load of the building.

The noise reduction effect of the double-skin structure 301 according to the present invention has been demonstrated by numerical analysis, and the results are shown below. FIG. 17 is a diagram showing a numerical analysis target.

The two-dimensional boundary element method was used for the numerical analysis. FIG. 17A is a basic double-skin structure 301 in which the sound insulating plate 330 is not provided, and the double-skin structure 301 in which 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 the direction of the depression angle of 45 degrees, and the sound energy passing through the virtual surface shown by the broken line in the drawing upward on the drawing was obtained by calculation.

The condition in which the sound insulation plate 330 shown in FIG. 17B is arranged (hereinafter referred to as the condition of "sound insulation plate B") and the condition in which the sound insulation plate 330 shown in FIG. Under the condition in which the sound insulating plate 330 and the sound absorbing material 340 shown in 17 (C) are arranged (hereinafter referred to as “condition of“ sound insulating plate C ”), the amount of reduction of the acoustic energy passing upward through the virtual surface, that is, the noise caused by the sound insulating plate. The reduction effect was sought. Note that FIG. 17B corresponds to the embodiment shown in FIG. 11, and FIG. 17C corresponds to the embodiment shown in FIG.

“Sound insulation plate B” shown in FIG. 17 (B) is a condition in which the sound insulation 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 openings.

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

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

Both the sound insulation plate B and the sound insulation plate C have a positive noise reduction effect, and it can be confirmed that the noise propagating in the air layer can be reduced by installing the sound insulation plate 330. Further, it can be confirmed that the sound insulation plate B has a noise reduction effect in a wide frequency range from 63 Hz to 4 kHz and the sound insulation plate C has a noise reduction effect 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.

1 ... Sound insulation louver 3 ... Louver blade members 4, 5 ... Main surface 10 ... Resonator 11 ... 1st section 12 ... 2nd section 13 ... 3rd section 14 ... 4th section 20 ... outer shell member 25 ... opening surface 30 ... L-shaped member 35 ... partition plate member 40 ... housing 50 ... slit-shaped opening 60 ... Partition plate 70 ... Partition plate member 100 ... Propagation path 210 ... Louver blade member 211 ... First opening 212 ... Second opening 215 ... Ventilation path 231 ... First straight line portion 232 ... 2nd straight line part 233 ... 3rd straight line part 234 ... 4th straight line part 240 ... Parabolic part (reflection part)
250 ... Arc part (reflection part)
260 ... Reinforcing rib 301 ... Double skin structure 304 ... Outer member 305 ... Inner member 307 ... Open end 330 ... Sound insulation plate 333 ... Flat surface 335 ... Standing Part 340 ... Sound absorbing material D ... Focus

Claims (4)

It is a double-skin structure constituting an outer wall portion of a building composed of an outer member, an inner member provided on the indoor side of the outer member at a predetermined interval, and an inner member.
A sound insulating louver in which a plurality of louver blade members are continuously arranged is arranged between the outer member and the inner member, and the sound insulating louver is arranged between the outer member and the inner member.
A double-skin structure characterized in that a resonator having a slit-shaped opening is arranged on the louver blade member. The double-skin structure according to claim 1, wherein a resonator is arranged on each of the two main surfaces of the louver blade member. The double-skin structure according to claim 1 or 2, wherein the slit-shaped openings of the resonators of the adjacent louver blade members are arranged so as to face each other. It is a double-skin structure constituting an outer wall portion of a building composed of an outer member, an inner member provided on the indoor side of the outer member at a predetermined interval, and an inner member.
A sound insulating louver in which a plurality of louver blade members are continuously arranged is arranged between the outer member and the inner member, and the sound insulating louver is arranged between the outer member and the inner member.
A plurality of reflective portions are formed in the ventilation path formed between the louver blade members, and at the same time, a plurality of reflective portions are formed.
A double-skin structure characterized in that sound incident on the first opening of the ventilation path is reflected by the plurality of reflecting portions and emitted from the first opening.

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