JP7807883B2 - Noise reduction structure - Google Patents

Description

The present invention relates to a noise reduction structure.

Patent Document 1 below describes a sound-insulating balcony structure in which the balcony ceiling is equipped with a reflective surface that reflects incident noise sound waves. In this sound-insulating balcony structure, the inclination angle of the reflective surface relative to the propagation direction of the direct noise waves is set to 90 degrees or more, thereby reducing noise incident on the building's window openings.

JP 2012-211509 A

The sound-insulating balcony structure in Patent Document 1 reflects noise to the outside of the building. Therefore, while it may be possible to reduce noise inside the building, it is difficult to reduce noise outside the building. This means that the reflected noise may affect other buildings.

In consideration of the above, the present invention aims to provide a noise reduction structure that can reduce noise both inside and outside a building.

The noise reduction structure of claim 1 comprises an inclined portion provided at the tip of a horizontal portion forming the ceiling surface of a balcony in a building and sloping so as to widen from the window surface toward the tip of the balcony , or an inclined portion provided at the tip of a vertical portion forming the side wall surface of the balcony in the building and sloping so as to widen from the window surface toward the tip of the balcony, and a sound-absorbing mechanism provided at the inclined portion and capable of absorbing noise.

In the noise reduction structure of claim 1, a sound-absorbing mechanism that absorbs noise is provided on a sloped portion provided on at least one of the balcony's ceiling and side wall surfaces. If the sound-absorbing mechanism is located on the sloped portion of the balcony's ceiling surface, it can absorb noise from below. Furthermore, if the sound-absorbing mechanism is located on the sloped portion of the balcony's side wall surface, it can absorb noise from the side.

This reduces noise both inside and outside the building compared to structures that use a "reflective surface" on the balcony ceiling to reflect noise.

In addition, by installing the sound-absorbing mechanism on the sloped portion of the balcony ceiling or side wall surface, rather than directly on the balcony ceiling or side wall surface, the sound-absorbing surface area of the sound-absorbing mechanism is increased, resulting in high sound-absorbing performance.

Furthermore, the sloped section widens from the window surface toward the end of the balcony, so it does not obstruct the view from inside the room or obstruct the natural lighting.

The noise reduction structure of claim 2 is provided on both the ceiling surface and side wall surface of a balcony in a building , and comprises an inclined portion that slopes so as to widen from the window surface toward the tip of the balcony, and a sound-absorbing mechanism that is provided on the inclined portion and is capable of absorbing noise.

In the noise reduction structure of claim 2, since the inclined portions are provided on both the ceiling surface and the side wall surface, noise incident from both below and the sides can be absorbed. This improves sound absorption performance compared to when the inclined portions are provided on only one of the ceiling surface and the side wall surface.

The noise reduction structure of claim 3 is the noise reduction structure of claim 1 or 2, in which the sound absorbing mechanism is formed from at least one of punched metal and porous material.

In the noise reduction structure of claim 3, the sound-absorbing mechanism is formed from at least one of punched metal and porous material. Therefore, even if the sound-absorbing mechanism is exposed to wind and rain, rainwater is less likely to accumulate and is easily drained. This makes the sound-absorbing mechanism less susceptible to deterioration.

This invention can reduce noise both inside and outside a building.

1A is a side cross-sectional view showing a noise reduction structure according to an embodiment, and FIG. 1B is a cross-sectional view taken along line BB in FIG. 1A. FIG. 1A is a partially enlarged cross-sectional view showing an example in which a punched metal is used as a sound-absorbing mechanism; FIG. 1B is a partially enlarged cross-sectional view showing an example in which a porous material is used as a sound-absorbing mechanism; and FIG. 1C is a partially enlarged cross-sectional view showing an example in which a punched metal and a porous material are used as a sound-absorbing mechanism. 1A is a side cross-sectional view showing a modification of the noise reduction structure according to the embodiment, and FIG. 1B is a cross-sectional view taken along line BB in FIG. 1A is a side cross-sectional view showing another modified example of the noise reduction structure according to the embodiment, and FIG. 1B is a cross-sectional view taken along line BB in FIG. 1A is a partially enlarged cross-sectional view showing a modified example of the arrangement of the sound-absorbing mechanism, FIG. 1B is a partially enlarged cross-sectional view showing another modified example, and FIG. 1C is a partially enlarged cross-sectional view showing yet another modified example. 1A is a side cross-sectional view showing a modified example in which an acoustic tube is used as a sound absorbing mechanism, and FIG. 1B is a side cross-sectional view showing variations in the arrangement of the acoustic tube. 1A is a cross-sectional view showing the configuration of an acoustic tube, and FIG. 1B is a graph showing the mechanism of the sound absorption effect of the acoustic tube. 1 is a front view showing a noise reduction structure according to an embodiment. FIG.

The noise reduction structure according to an embodiment of the present invention will now be described with reference to the drawings. Components indicated with the same reference numerals in the various drawings are the same components. However, unless otherwise specified in the specification, each component is not limited to one, and multiple components may be present.

Furthermore, explanations of overlapping components and symbols may be omitted in each drawing. Note that the present invention is not limited to the following embodiments, and can be implemented by making appropriate modifications, such as omitting components or replacing them with different components, within the scope of the purpose of the present invention.

In each figure, the directions indicated by arrows X and Y are directions along a horizontal plane and are perpendicular to each other. Furthermore, the direction indicated by arrow Z is a direction along the vertical direction (up and down). In each figure, the directions indicated by arrows X, Y, and Z are assumed to coincide with each other.

<Noise reduction structure>
1(A) and 1(B) show a noise reduction structure 20 according to an embodiment of the present invention. The noise reduction structure 20 is applied to a building 10 and is a noise reduction means intended to reduce noise both inside and outside the building 10. The noise reduction structure 20 is configured to include a ceiling member 30, a partition member 40, and a perforated metal 50 as a sound-absorbing mechanism, which will be described later.

(building)
Although the use of the building 10 is not particularly limited, the building 10 in this embodiment is an apartment building. The noise reduction structure 20 is applied to a balcony 12 of the building 10.

A main road (not shown) (such as a national expressway, national highway, or prefectural road) runs in front of the balcony 12 of the building 10. The longitudinal direction (X direction) of the balcony 12 is aligned with the direction of the lanes on the main road. Note that the front of the building 10 does not necessarily have to be a main road; for example, various roads other than main roads, train tracks, etc. may also run in front of the building 10.

The balcony 12 is an outdoor space separated from the indoor space R of the building 10 by a glass window 14. The glass window 14 is a sliding window that allows access from the indoor space R to the balcony 12, and is arranged along the longitudinal direction of the balcony 12. A slab 16 is formed on the outside of the glass window 14.

The slabs 16 are cantilevered slabs that protrude outward from the building 10 and are provided on each floor of the building 10, forming the floor surface of the veranda 12 on each floor. Handrails 16A are provided at the ends of the slabs 16.

In this embodiment, an example is shown in which two dwelling units are arranged in the part of the building 10 facing the main road, but the number of dwelling units arranged in the part facing the main road is not particularly limited.

(ceiling components)
As shown in Figure 1(A), in the balcony 12, a ceiling member 30 is provided below the slab 16 that forms the floor surface of the upper floor. This ceiling member 30 has a horizontal portion 32 and an inclined portion 34. The horizontal portion 32 and the inclined portion 34 are each formed using a non-combustible board material such as a calcium silicate board.

The horizontal section 32 is a section formed horizontally below the slab 16 and is located on the exterior wall surface side of the building 10. On the other hand, the inclined section 34 is a section formed below the slab 16 and inclined upward relative to the horizontal section 32, and is located from the tip of the horizontal section 10 to the tip of the slab 16. The inclined section 34 is inclined so as to widen from the window surface of the glass window 14 toward the tip of the balcony 12. The inclined section 34 may also be curved.

The undersides of the horizontal portion 32 and the inclined portion 34 form the ceiling surface of the balcony 12. The inclined portion 34 is an example of an "inclined portion provided on the ceiling surface of the balcony" in the present invention.

The space V1 formed between the slab 16 that forms the floor surface of the upper floor and the ceiling member 30 can be used as space for installing equipment and piping.

It is preferable that the horizontal section 32 and the inclined section 34 are fixed to a base material made of a metal material such as aluminum or steel, or fitted into a frame or similar. This ensures that the ceiling member 30 is rigid enough to prevent deformation or scattering when blown about by the wind.

(Partition plate member)
As shown in Figure 1(B), the balcony 12 is divided by partition members 40. The partition members 40 are installed at the boundary between adjacent dwelling units, dividing the balcony 12 into multiple exclusive use areas and forming the side walls of these exclusive use areas. An "exclusive use area" is an area that is used daily only by the residents of a single dwelling unit.

The partition member 40 has two vertical sections 42 and 44 and an inclined section 46. The vertical sections 42, 44 and the inclined section 46 are each formed using a non-flammable plate material such as a calcium silicate board or a flexible board.

The vertical section 42 is a section formed along the vertical direction between the upper and lower slabs 16, and is located on the exterior wall surface side of the building 10. Furthermore, the vertical section 42 is located along the short side (Y direction) of the balcony 12, and is longer in the Y direction than the vertical section 44.

Like vertical section 42, vertical section 44 is a section formed vertically between the upper and lower slabs 16 and is located on the exterior wall surface side of the building 10. Furthermore, vertical section 44 is spaced apart from vertical section 42 in the longitudinal direction of the balcony 12 and is located parallel to vertical section 42.

The inclined portion 46 is a portion that connects the tip of the vertical portion 42 and the tip of the vertical portion 44. The inclined portion 46 is a portion formed between the upper and lower slabs 16, inclined toward the outside of the glass window 14 relative to the connected vertical portion 44 (in other words, a portion that inclins relative to the vertical portion 44 so as to widen from the window surface of the glass window 14 toward the tip of the balcony 12). The inclined portion 46 may also be curved.

The vertical portions 42, 44 and the inclined portion 46 form the side wall surface of the dedicated use portion of the balcony 12. The inclined portion 46 is an example of the "inclined portion provided on the side wall surface of the balcony" in this invention. The space V2 formed between the vertical portions 42, 44 and the inclined portion 46 can be used as space for installing equipment and piping.

It is preferable that the vertical sections 42, 44 and the inclined section 46 are fixed to a base material made of a metal material such as aluminum or steel, or fitted into a frame or similar. This ensures that the partition member 40 is rigid enough to prevent deformation or scattering when blown by the wind.

Here, as shown in Figure 8, the upper end of the inclined portion 46 of the partition member 40 is joined to the lateral end of the inclined portion 34 of the ceiling member 30.

In other words, when viewing the balcony 12 from the front (direction Y), the inclined portions 46 and 34 form a gate-shaped frame that surrounds the glass window 14 on three sides (the glass window 14 on the "left" side of the page in Figure 8).

Furthermore, the inclined portion 46 and the inclined portion 34 form an L-shaped frame that surrounds the glass window 14 on two sides (the glass window 14 on the "right" side of the paper in Figure 8).

(sound absorbing mechanism)
1A and 8, a perforated metal 50 is provided on the surface of the inclined portion 34 of the ceiling member 30. The perforated metal 50 is an example of a sound absorbing mechanism of the present invention.

As shown in Figures 1(B) and 8, the perforated metal 50 is also provided on the surface of the inclined portion 46 of the partition member 40. Furthermore, the perforated metal 50 covers almost the entire surface of the inclined portions 34 and 46.

As shown in Figure 2(A), the perforated metal 50 is a steel or aluminum plate with multiple through holes 52 formed at predetermined intervals in the in-plane direction. The perforated metal 50 is fixed to the surfaces of the inclined portions 34 and 46 using appropriate fixing means such as bolts or adhesive.

The sound-absorbing mechanism of the present invention may also be a porous material 54 as shown in Figure 2(B). For example, foamed polypropylene with voids may be used as the porous material 54. Alternatively, urethane or the like may also be used as the porous material 54.

The sound-absorbing mechanism of the present invention can also be a combination of perforated metal 50 and porous material 54, as shown in Figure 2(C). The specifications of these sound-absorbing mechanisms may be changed depending on the location where they are applied. For example, perforated metal 50 may be used for inclined portion 34, and porous material 54 may be used for inclined portion 46.

Note that the "sound absorption" performance of the sound-absorbing mechanism of the present invention refers to the ability to absorb (deaden) at least a portion of the incident sound. Incident sound that is not absorbed may be reflected to the outside.

To achieve this sound-absorbing performance, the sound-absorbing mechanism has holes (through-holes 52 in the punched metal 50 or air bubbles in the porous material 54) for absorbing incident sound. On the other hand, the "reflective surface" that is not a sound-absorbing mechanism is, for example, a smooth, hard surface made of a heavy material such as metal.

<Action and effect>
In the noise reduction structure 20 according to an embodiment of the present invention, as shown in Figures 1(A) and (B), a sound-absorbing mechanism for absorbing noise is provided on an inclined portion provided on at least one of the ceiling surface and side wall surface of the balcony 12.

Specifically, perforated metal 50 serving as a sound-absorbing mechanism is provided on the inclined portion 34 of the ceiling member 30 that forms the ceiling surface of the balcony 12, and perforated metal 50 is also provided on the inclined portion 46 of the partition member 40 that forms the side wall surface of the balcony 12.

By placing the sound-absorbing mechanism on the sloped portion 34 of the ceiling surface of the balcony 12, noise from below, as indicated by arrow N1 in Figure 1(A), can be absorbed. In particular, on the upper floors of the building 10, noise emitted from vehicles traveling on the road in front, which is the main noise source, enters from below. By providing a sound-absorbing surface or sound-absorbing mechanism on the ceiling surface, this type of noise can be efficiently reduced.

Furthermore, because the sound-absorbing mechanism is located on the sloped portion 46 of the side wall surface of the balcony 12, it can absorb noise from the side as indicated by arrow N2 in Figure 1(B). For example, the angle of the noise incident on the side wall surface changes as vehicles travel on the road in front of the building 10, but the noise can be reduced regardless of the change in the angle of incidence.

This reduces noise both inside and outside the building 10 compared to a structure that reflects noise by providing a "reflective surface" on the ceiling or side wall of the balcony 12. In contrast, if a "reflective surface" is provided on the ceiling or side wall of the balcony 12, most of the noise will be reflected outside the building 10, making it difficult to reduce noise outside the building 10.

In addition, by providing a sound-absorbing mechanism on the inclined portions 34 and 46, reflected sound is suppressed, thereby reducing the incidence of rubbing reflected sound on the glass window 14. This reduces the reduction in sound insulation due to the coincidence effect between the glass and rubbing incident sound.

In addition, by providing the perforated metal 50 as a sound-absorbing mechanism on the sloped portions 34 and 46 of the balcony ceiling and side walls, rather than providing the sound-absorbing mechanism directly on the ceiling or side walls of the balcony 12, the sound-absorbing surface area of the perforated metal 50 is increased, thereby achieving high sound-absorbing performance.

In other words, the area of the inclined portion 34 is larger than the area of region M shown in Figure 1 (A). Region M is the horizontal projection of the inclined portion 34 onto the slab 16, and the area of region M is the horizontal projection area of the inclined portion 34. While the inclined portion 34 and region M require equal areas in terms of floor plan, the actual area of the inclined portion 34 is larger. Therefore, the inclined portion 34 has a larger area in which the perforated metal 50 can be installed, making it easier to demonstrate sound absorption performance. The same is true for the inclined portion 46. In other words, by providing sound-absorbing mechanisms to the inclined portions 34 and 46, noise can be reduced over a wider range of incident angles.

Furthermore, since the inclined portion 34 is inclined so as to widen from the surface of the glass window 14 toward the tip of the balcony 12 (in other words, the tip of the slab 16), it is also easy to absorb noise from the front as indicated by arrow N3 in Figure 1(A). Similarly, since the inclined portion 46 is inclined so as to widen from the surface of the glass window 14 toward the tip of the balcony 12, it can also absorb noise from the front as indicated by arrow N4 in Figure 1(B).

Furthermore, these inclined portions 34 and 46 are inclined so as to widen from the window surface of the glass window 14 toward the tip of the balcony 12, making it less likely to obstruct the view from the indoor space R or to obstruct natural lighting. Furthermore, when the balcony 12 is viewed from the front, the inclined portions 34 and 46 are inclined so as to recede toward the glass window 14, thereby reducing the feeling of oppression felt by the building 10.

In addition, in the noise reduction structure 20 according to an embodiment of the present invention, the sound absorbing mechanism is formed from at least one of a perforated metal 50 and a porous material 54. Specifically, the sound absorbing mechanism is formed from a perforated metal 50 shown in FIG. 2(A), a porous material 54 shown in FIG. 2(B), or a composite of a perforated metal 50 and a porous material 54 shown in FIG. 2(C).

As a result, even if the sound-absorbing mechanism is exposed to wind and rain, rainwater is less likely to accumulate and is easily drained. This makes the sound-absorbing mechanism less likely to deteriorate.

<Modification>
(Modifications regarding the arrangement of the sound absorbing mechanism)
1A and 1B, in the noise reduction structure 20 according to this embodiment, perforated metal 50 serving as a sound-absorbing mechanism is provided on both the inclined portions 34 and 46 formed on the ceiling surface and the side wall surface of the balcony 12, but the embodiment of the present invention is not limited to this. For example, a configuration may be adopted in which a sound-absorbing mechanism is not provided on either the inclined portions 34 or 46.

Also, as shown in Figures 3(A) and (B), for example, the partition member may be formed only by the vertical portion 42, and a perforated metal 50 acting as a sound-absorbing mechanism may be provided on the inclined portion 34 formed on the ceiling surface of the balcony 12. The vertical portion 42 may or may not be provided with a sound-absorbing mechanism. Furthermore, the balcony 12 may not be provided with a partition member. A configuration without a partition member can be applied to buildings such as hospitals and public buildings.

Also, as shown in Figures 4(A) and (B), for example, the ceiling member 30 (see Figure 1) may be omitted, and a perforated metal 50 acting as a sound-absorbing mechanism may be provided on the sloped portion 46 formed on the side wall surface of the balcony 12. A sound-absorbing mechanism may or may not be provided on the underside of the slab 16.

In other words, in the present invention, it is sufficient that an inclined portion (i.e., at least one of inclined portions 34 and 46) is provided on at least one of the ceiling surface and side wall surface of the balcony 12, and that a sound-absorbing mechanism is provided on at least one of these inclined portions 34 and 46.

In this case, the sound-absorbing mechanism may be provided on part of the inclined portion 46, as in the perforated metal 50 shown in Figure 5(A). The sound-absorbing mechanism may also be placed in a position that includes the vertical portion 44, as in the perforated metal 50 shown in Figure 5(B). The sound-absorbing mechanism fixed to the vertical portion 44 may also cover part of the vertical portion 44, as shown in Figure 5(C).

Note that various modifications regarding the placement of these sound-absorbing mechanisms can also be applied to the placement of the acoustic tube 60, which will be described later.

(Modifications regarding specifications of sound absorbing mechanism)
In the noise reduction structure 20 according to this embodiment, as explained using Figures 2(A) to (C), the sound absorbing mechanism is formed from at least one of the punched metal 50 and the porous material 54, but the embodiment of the present invention is not limited to this.

For example, the sound absorbing mechanism can be formed using an acoustic tube 60, as shown in Figures 6(A) and (B). The acoustic tube 60 is a cylindrical tube with a bottom, as shown in Figure 7(A). Noise that enters the acoustic tube 60, as indicated by arrow N5, is reflected by the bottom 62 of the acoustic tube 60 and is emitted from the acoustic tube 60, as indicated by arrow N6.

In Figure 7(B), the waveforms of the incident and reflected sound waves of wavelength λ measured at the open end of the acoustic tube 60 are shown by curves K1 and K2, respectively. Because the phases of the incident and reflected sound waves of wavelength λ are shifted by half a wavelength (0.5λ) at the open end of the acoustic tube 60, they interfere with each other, resulting in a sound absorption effect.

Because the length L of the acoustic tube 60 is (0.25λ), the incident and reflected sound waves of wavelength λ are shifted in phase by half a wavelength (0.5λ) at the open end of the acoustic tube 60. In other words, noise of various wavelengths enters the acoustic tube 60, but noise whose length equivalent to 0.25 times the wavelength λ matches the length L of the acoustic tube 60 is absorbed.

As shown in Figure 6(A), the sound absorbing mechanism of this embodiment uses a combination of multiple acoustic tubes 60 of different lengths. Specifically, each acoustic tube 60 is positioned with its open end facing downward and its cylindrical axis aligned vertically.

Furthermore, the length of the acoustic tube 60 located at the tip of the balcony 12 is shorter than the length of the acoustic tube 60 located near the glass window 14 on the balcony 12.

As a result, the acoustic tube 60 located closer to the glass window 14 absorbs noise with relatively long wavelengths (low sounds), while the acoustic tube 60 located at the tip of the balcony 12 absorbs noise with short wavelengths (high sounds). The length of the acoustic tube 60 can be varied as needed depending on the wavelength of the noise to be absorbed.

The acoustic tubes 60 can also be arranged as shown in Figure 6(B). In the example shown in this figure, each acoustic tube 60 is arranged with its open end facing the tip of the balcony 12 and its cylindrical axis running horizontally (from the glass window 14 toward the tip of the balcony 12).

Furthermore, the length of the acoustic tubes 60 located below the balcony 12 is shorter than the length of the acoustic tubes 60 located above the balcony 12 and closer to the slab 16.

As a result, the acoustic tube 60 located closer to the slab 16 absorbs noise with relatively long wavelengths (low sounds), while the acoustic tube 60 located below absorbs noise with relatively short wavelengths (high sounds).

In this way, the term "inclined portion provided on the ceiling surface of the balcony and sloping so as to widen from the window surface toward the end of the balcony" in this invention also includes an inclined portion formed by the open ends of multiple acoustic tubes 60 of different lengths.

Although not shown in the figures, the acoustic tube 60 may be provided on the side wall surface of the balcony 12 in addition to or instead of the ceiling surface of the balcony 12. In this case, too, the open end of the acoustic tube 60 is positioned so as to form a sloped portion that widens from the glass window 14 toward the tip of the balcony 12.

As such, the sound-absorbing mechanism of the present invention is not particularly limited in its configuration as long as it absorbs noise. For example, various perforated plates other than punched metal 50 can also be used as resonators. Furthermore, the sound-absorbing mechanism may also be a sound-absorbing plate that absorbs sound by vibrating in accordance with the frequency of the incident noise.

10 Building 12 Balcony 14 Glass window (window)
30 Ceiling material (ceiling)
34 Inclined portion 40 Partition plate member (side wall)
46 Inclined portion 50 Punching metal (sound absorbing mechanism)
54 Porous material (sound absorption mechanism)
60 Acoustic tube (sound absorbing mechanism)

Claims (3)

an inclined portion provided at the tip of a horizontal portion forming the ceiling surface of a balcony in the building and inclined so as to widen from the window surface toward the tip of the balcony , or an inclined portion provided at the tip of a vertical portion forming the side wall surface of the balcony in the building and inclined so as to widen from the window surface toward the tip of the balcony;
a sound absorbing mechanism provided on the inclined portion and capable of absorbing noise;
Noise reduction structure. an inclined portion provided on both the ceiling surface and the side wall surface of the balcony in the building, and inclined so as to widen from the window surface toward the tip of the balcony;
a sound absorbing mechanism provided on the inclined portion and capable of absorbing noise;
Noise reduction structure. The noise reduction structure described in claim 1 or 2, wherein the sound absorbing mechanism is formed from at least one of punched metal and porous material.