JP2018071154A - louver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain desired sound absorption performance even in outdoor use while securing air distribution with a simpler structure.SOLUTION: A louver 11 includes a plurality of extrusion molding materials 21 arranged at prescribed intervals. Each extrusion molding material 21 is formed by a wooden member. The outer shape of the extrusion molding material 21 is formed into a rectangular parallelepiped shape. The thickness of the extrusion molding material 21 on a longitudinal side is set within a prescribed range. A rectangular parallelepiped hollow part is formed inside the extrusion molding material 21. On one of the longitudinal sides of the extrusion molding material 21, a plurality of holes 41 are formed so as to communicate with the hollow part 51 at prescribed intervals in a longitudinal direction.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a louver, and more particularly to a louver for use in a building.

  Louvers are provided in buildings to selectively block or transmit light, field of view, and the like. Such a louver is constructed by assembling elongated members with a gap. Generally, a louver is used for the purpose of blocking the line of sight while ensuring air circulation.

  On the other hand, in facilities and buildings where noise is generated, noise suppression such as sound insulation and sound absorption is required.

  As a conventional sound insulating material, a material having a relatively high density, that is, a heavy material is used to form a wall surface. In this case, sound insulation is obtained by creating a closed space that blocks the line of sight and does not circulate air.

  In addition, as a sound absorbing material used outside (outdoors), a perforated plate (so-called punching metal) in which small-diameter holes are continuously formed is used. As a sound absorbing material used inside (indoor), a metal panel containing a fibrous sound absorbing material such as glass wool or rock wool is used. This sound-absorbing material obtains a sound-absorbing effect by converting vibration caused by sound pressure into frictional heat of fibers, and is used in a room or a closed space.

  Furthermore, there is also a louver body provided with an opening for inserting a sound absorbing material on the opposite surface of the decorative surface, and a cover material covering the opening of the louver body (see, for example, Patent Document 1). In this soundproof louver, the louver body includes an engaging portion that rises substantially perpendicular to the opening direction of the opening, and the cover member includes a locking portion that engages with the engaging portion. In addition, a sound passage hole is provided in at least one of the decorative surfaces of the louver body and the cover material.

JP 2013-213334 A

  However, when noise is to be suppressed using a sound insulating material, it is necessary to create a closed space, and thus air circulation cannot be ensured. Moreover, the sound absorption effect of punching metal is small.

  Furthermore, in the case of storing the fibrous sound absorbing material, the sound absorbing performance deteriorates when wetted with water. Therefore, when used outdoors, it is necessary to embed it in a metal cover or the like. If it is installed in a metal cover or the like, the structure becomes complicated and the sound absorbing performance is also lowered.

  The present invention has been made in view of such a situation, and is intended to maintain a desired sound absorption performance even when used outdoors while ensuring air circulation with a simpler structure. .

  The louver according to one aspect of the present invention has a wooden shape in which an outer shape is formed in a rectangular parallelepiped shape, a thickness on a side surface in a longitudinal direction is formed within a predetermined range, and a rectangular parallelepiped hollow portion is formed inside. The member is composed of a plurality of members arranged at a predetermined gap, and a plurality of holes that lead to the hollow portion are provided at predetermined intervals in the longitudinal direction on any of the longitudinal side surfaces of each member. Yes.

  With the cross-sectional shape of the hollow portion being a constant cross-sectional shape in a plane orthogonal to the side surface in the longitudinal direction of the member, the hollow portion can be opened at the end portion in the longitudinal direction of the member.

  The holes can be provided on the side surface in the longitudinal direction of the member so as to be arranged in a line in the longitudinal direction.

  The holes can be provided at regular intervals.

  The direction of the side surface provided with the hole in one member of the plurality of members can be the same as the direction of the side surface provided with the hole in the other member of the plurality of members.

  A side surface provided with a hole in one member can be a side surface adjacent to the other member.

  Of the side surfaces in the longitudinal direction of each member, each of the plurality of side surfaces can be provided with a plurality of holes having a predetermined cross-sectional area that are arranged at predetermined intervals in the longitudinal direction and communicate with the hollow portion.

  Two hollow portions arranged in the longitudinal direction of the side surface of the member can be formed inside each member.

  The cross-sectional shapes of the two hollow portions and the cross-sectional shapes in the plane orthogonal to the side surface in the longitudinal direction of the member can be made substantially the same.

  A hole is provided on each of the two side surfaces of the side surfaces in the longitudinal direction of the member, and the hole provided on one side surface is communicated with one hollow portion of the plurality of hollow portions, and on the other side surface. The provided hole can be communicated with the other hollow portion of the plurality of hollow portions.

  The member can be formed from recycled wood.

  The member can be extruded.

  In one aspect of the present invention, a wooden member having an outer shape formed in a rectangular parallelepiped shape, a thickness on a side surface in a longitudinal direction within a predetermined range, and a rectangular parallelepiped hollow portion formed inside Since a plurality of holes communicating with the hollow portion are provided at predetermined intervals in the longitudinal direction on any one of the side surfaces in the longitudinal direction, sound can be absorbed by the Helmholtz resonance effect with a simpler structure. Since a sound absorbing material such as a fibrous material is not required, the sound absorbing performance is not deteriorated by being wet with water, and the desired sound absorbing performance can be maintained even when used outdoors. Since a plurality of members are arranged at a predetermined gap, air circulation can be secured. Therefore, the desired sound absorbing performance can be maintained even when used outdoors with a simpler structure and ensuring air circulation.

  As described above, according to the present invention, it is possible to maintain a desired sound absorption performance even when used outdoors while ensuring air circulation with a simpler structure.

2 is a front view showing an example of the overall configuration of a louver 11. FIG. 2 is a rear view showing an example of the overall configuration of a louver 11. FIG. 3 is a perspective view showing an example of the configuration of an extruded material 21. FIG. 3 is a front view showing an example of the configuration of an extruded material 21. FIG. 4 is a rear view showing an example of the configuration of the extruded material 21. FIG. 3 is a right side view showing an example of the configuration of an extrusion molding material 21. FIG. 3 is a left side view showing an example of the configuration of an extrusion molding material 21. FIG. 3 is a plan view showing an example of the configuration of an extrusion molding material 21. FIG. 3 is a cross-sectional view showing an example of the configuration of an extrusion molding material 21. FIG. It is a figure which shows the example of the transmission loss of the louver. It is a figure which shows the example of the sound absorption rate of the louver. It is a figure which shows the example of the sound absorption rate of the louver. It is a figure which shows the example of the sound absorption rate of the louver. It is a figure which shows the example of the sound absorption rate of the louver.

  Embodiments of the present invention will be described below. Correspondences between the configuration requirements of the present invention and the embodiments described in the detailed description of the present invention are exemplified as follows. This description is to confirm that the embodiments supporting the present invention are described in the detailed description of the invention. Accordingly, although there are embodiments that are described in the detailed description of the invention but are not described here as embodiments corresponding to the constituent elements of the present invention, It does not mean that the embodiment does not correspond to the configuration requirements. Conversely, even if an embodiment is described here as corresponding to a configuration requirement, that means that the embodiment does not correspond to a configuration requirement other than the configuration requirement. It's not something to do.

  The louver according to one aspect of the present invention (for example, the louver 11 in FIG. 1) has an outer shape formed in a rectangular parallelepiped shape, a thickness on a side surface in a longitudinal direction is formed within a predetermined range, and a rectangular parallelepiped shape on the inside. It is a wooden member in which a hollow part is formed, and is composed of a plurality of members (for example, the extrusion molding material 21 in FIG. 3) arranged at a predetermined gap, and is provided on any one of the side surfaces in the longitudinal direction of each member. Are provided with a plurality of holes (for example, holes 41 in FIG. 3) that communicate with the hollow portion at predetermined intervals in the longitudinal direction.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  First, with reference to FIG. 1 and FIG. 2, the example of the whole structure of the louver 11 of one embodiment of this invention is demonstrated. 1 and 2 are a front view and a rear view, respectively, showing an example of the overall configuration of the louver 11.

  The louver 11 is composed of a plurality of extrusion molding materials 21. The outer shape of the extrusion molding material 21 is formed in a columnar shape. The plurality of extrusion molding materials 21 constituting the louver 11 are arranged with a predetermined gap. Thereby, the louver 11 blocks the line of sight while ensuring air circulation.

  Although details will be described later, a hollow portion is formed inside the extrusion molding material 21. On the side surface of the extrusion molding material 21, a hole 41 leading to the hollow portion is formed. The louver 11 absorbs sound due to the Helmholtz resonance effect obtained from the hollow portion and the hole 41 formed inside the extrusion molding material 21. That is, the louver 11 has a sound absorbing property.

  For example, as shown in FIG. 1, the louver 11 is installed in front of an outdoor unit 31 of an air conditioner that is an example of a sound source, and absorbs noise from the outdoor unit 31 while ensuring air circulation.

  For example, the louver 11 is used by being installed along the outer wall of a building of a commercial facility or installed at the boundary of a house. Further, for example, the louver 11 is installed at a boundary between a facility such as a kindergarten or a nursery school and a road or another house. The louver 11 blocks the line of sight and absorbs noise while ensuring air circulation.

  In the following, the front-rear direction with respect to the louver 11 is indicated by the Y axis, the upper and lower directions are indicated by the Z axis, and the left and right directions are indicated by the X axis. Hereinafter, the left side in FIG. 1 in the X-axis direction is also simply referred to as the left side, and the right side in FIG. Further, hereinafter, the front side in FIG. 1 in the Y-axis direction is also simply referred to as the front side, and the back side in FIG. 1 in the Y-axis direction is also simply referred to as the rear side. Furthermore, hereinafter, the upper side in FIG. 1 in the Z-axis direction is also simply referred to as the upper side, and the lower side in FIG. 1 in the Z-axis direction is also simply referred to as the lower side. Note that the Z-axis direction is also simply referred to as the vertical direction, and the direction along the plane parallel to the X-axis and Y-axis is also simply referred to as the horizontal direction or the horizontal direction.

  In the louver 11 shown in FIGS. 1 and 2, the plurality of extruded materials 21 are linearly arranged at the same interval in the left-right direction. Moreover, in the louver 11 shown in FIGS. 1 and 2, the lengths in the vertical direction of each of the plurality of extruded molding materials 21 are the same. In the louver 11 shown in FIGS. 1 and 2, the plurality of extruded materials 21 are arranged so that the side surfaces are parallel. In the louver 11 shown in FIGS. 1 and 2, the plurality of extruded molding materials 21 have the same structure. In the louver 11 shown in FIGS. 1 and 2, the plurality of extruded materials 21 are arranged so that the side surfaces in the longitudinal direction are in the vertical direction.

  As an example, the height (length in the vertical direction) of the louver 11 can be set to 1.5 m to 3 m. For example, the width (length in the left-right direction) of the extrusion molding material 21 can be set to 3.5 cm. Furthermore, for example, the depth (length in the front-rear direction) of the extrusion molding material 21 can be 10 cm. Further, for example, the interval between the plurality of extrusion molding materials 21 can be set to 6.5 cm. In addition, the height, width, depth, and interval of the louver 11 can be arbitrarily set as appropriate.

  In the louver 11, the gap in which the extrusion molding material 21 is arranged can be a fixed length or can be changed depending on the part. In the louver 11, the extrusion molding material 21 can also be arrange | positioned linearly and can also be arrange | positioned at curvilinear form.

  Moreover, in the louver 11, you may make it change each length of the extrusion molding material 21. FIG. In the louver 11, the widths of the extrusion molding materials 21 may be changed. In the louver 11, each depth of the extrusion molding material 21 may be changed. Furthermore, in the louver 11, you may make it arrange | position so that the some extrusion molding material 21 may be piled up and down. Further, in the louver 11, a plurality of upper extrusion materials 21 and a plurality of lower extrusion materials 21, a lower end of the upper extrusion material 21, and an upper side of the lower extrusion material 21. You may make it arrange | position alternately so that it may be pinched | interposed in the edge part.

  In the louver 11, the extrusion molding material 21 may be arranged so that the side surfaces are non-parallel.

  Further, the louver 11 may be made of the extruded materials 21 having different structures.

  In the louver 11, the plurality of extrusion molding materials 21 may be arranged so that the side surfaces in the longitudinal direction are in the horizontal direction or with a predetermined inclination.

  Next, an example of the configuration of the extruded material 21 will be described with reference to FIGS. 3 to 9. 3 to 9 are a perspective view, a front view, a rear view, a right side view, a left side view, a plan view, and a cross-sectional view showing an example of the configuration of the extrusion molding material 21, respectively. Since the bottom view is the same as the plan view, it is omitted. The cross-sectional view of FIG. 9 shows a cross section taken along the line AA 'shown in the left side view of FIG.

  The extruded material 21 is made of recycled wood. Moreover, the extrusion molding material 21 is extrusion-molded.

  The outer shape of the extrusion molding material 21 is formed in a columnar shape. In other words, the outer shape of the extrusion molding material 21 is formed in a rectangular parallelepiped shape. The outer shape of the extruded material 21 is longer in the vertical direction than in the horizontal direction. A plurality of holes 41 are provided at predetermined intervals in the vertical direction on the side surface on the back side of the extruded material 21. A plurality of holes 42 are provided on the left side surface of the extruded material 21 at predetermined intervals in the vertical direction. Each of the holes 41 and 42 has a circular cross section. For example, the diameter of each of the hole 41 and the hole 42 can be 1 mm to 30 mm. The diameter of each of the holes 41 and 42 is set to a predetermined value so that a resonance frequency by a Helmholtz resonance effect described later is a desired frequency.

  A rectangular parallelepiped hollow portion 51 and a hollow portion 52 are formed inside the extrusion molding material 21. The hollow portion 51 and the hollow portion 52 extend parallel to each other in the Z-axis direction. That is, the hollow portion 51 and the hollow portion 52 are arranged in the longitudinal direction of the side surface of the extrusion molding material 21. The horizontal sections of the hollow portion 51 and the hollow portion 52 are substantially the same. In other words, the cross-sectional shapes of the hollow part 51 and the hollow part 52 and the cross-sectional shapes in the plane orthogonal to the side surface in the longitudinal direction of the extruded material 21 are substantially the same. The hollow portion 51 and the hollow portion 52 are open at both ends in the Z-axis direction of the extruded material 21. That is, the hollow part 51 and the hollow part 52 are open at the end in the longitudinal direction of the extrusion molding material 21.

  The thicknesses of the front side surface, the back side surface, the right side surface, and the left side surface of the extruded material 21 are substantially constant. For example, the thickness of the front side surface, the back side surface, the right side surface, and the left side surface of the extrusion molding material 21 is set to a substantially constant thickness in the range of 4 mm to 7 mm. That is, the thickness of the side surface in the longitudinal direction of the extrusion molding material 21 is formed within a predetermined range. The thickness of the side surface in the longitudinal direction of the extruded material 21 is set to a predetermined value so that the resonance frequency due to the Helmholtz resonance effect described later is a desired frequency.

  As shown in FIG. 9, the hole 41 provided in the side surface on the back surface side of the extrusion molding material 21 communicates with the hollow portion 51. That is, the hole 41 opens on the side surface on the back surface side of the extrusion molding material 21 and opens on the wall surface of the hollow portion 51 inside the extrusion molding material 21.

  Further, as shown in FIG. 9, the hole 42 provided in the left side surface of the extruded material 21 communicates with the hollow portion 52. That is, the hole 42 opens on the left side surface of the extruded material 21 and opens on the wall surface of the hollow portion 52 inside the extruded material 21.

  For example, the holes 41 are formed on the side surface on the back side of the extruded material 21 so as to be aligned on a straight line in the Z-axis direction. Further, for example, the holes 42 are formed on the left side surface of the extruded material 21 so as to be aligned on a straight line in the Z-axis direction. That is, the holes 41 are provided on the side surface in the longitudinal direction of the extruded material 21 so as to be aligned in a line in the longitudinal direction. Similarly, the holes 42 are provided on the side surface in the longitudinal direction of the extruded material 21 so as to be aligned in a row in the longitudinal direction.

  The holes 41 are formed on the side surface on the back side at equal intervals in the Z-axis direction. In other words, the distance between the centers of the cross-sections of two adjacent holes 41 is the same as the distance between the centers of the cross-sections of the two adjacent holes 41 obtained by shifting the holes 41 by one. That is, the holes 41 are provided at equal intervals.

  Similarly, the holes 42 are formed on the left side surface at equal intervals in the Z-axis direction. In other words, the distance between the centers of the predetermined cross-sections of the two adjacent holes 42 is the same as the distance between the centers of the cross-sections of the two adjacent holes 42 obtained by shifting the holes 42 by one. That is, the holes 42 are provided at equal intervals.

  In the louver 11, the plurality of extrusion molding materials 21 have the same structure, and the respective extrusion molding materials 21 are arranged in the same direction. Therefore, in the plurality of extrusion molding materials 21, the side surfaces on which the holes 41 or the holes 42 are formed are formed. The direction is the same. That is, the direction of the side surface in which the hole 41 or the hole 42 is provided in one of the plurality of extrusion molding materials 21 is the hole in the other extrusion molding material 21 of the plurality of extrusion molding materials 21. 41 or the direction of the side surface in which the hole 42 is provided.

  In the louver 11, the plurality of extrusion molding materials 21 are arranged so that the right side surface and the left side surface are adjacent to each other. Therefore, the left side surface in which the holes 42 are provided in the predetermined extrusion molding material 21 is the other extrusion molding material. Adjacent to the right side of 21. In other words, the side surface provided with the hole 42 in one extrusion molding material 21 among the plurality of extrusion molding materials 21 is a side surface adjacent to the other extrusion molding material 21.

  Here, the Helmholtz resonance effect will be described. In the extrusion molding material 21 of the louver 11, the hollow portion 51 and the hollow portion 52 correspond to cavities, and the holes 41 and 42 that communicate with the hollow portions 51 and 52 respectively correspond to resonators. When sound waves are incident on the holes 41 and 42, which are the resonators, the air inside the holes 41 and 42 vibrates vigorously at the resonance frequencies of the air springs of the hollow portions 51 and the hollow portions 52. To do. At this time, sound is absorbed by the respective friction losses of the hollow portion 51 and the hollow portion 52.

The sound absorption characteristic of the resonator is expressed by Equation (1) indicating the resonance frequency f0 due to the Helmholtz resonance effect.
f0 = c / 2π × (P / (L (l + l '))) ^ (1/2) (1)

  In equation (1), the speed of sound c indicates the speed of sound, and the aperture ratio P indicates the area of the opening of the hole 41 between the width of the hollow portion 51 with respect to the side surface where the hole 41 is provided and the interval between the holes 41. The value obtained by dividing by the multiplier is shown. The air layer thickness L is a distance from the wall surface of the hollow portion 51 where the hole 41 is opened to the wall surface facing the wall surface. The neck length l is the length of the hole 41, that is, the thickness of the side surface of the extruded material 21 in which the hole 41 is formed. The opening end correction l 'is called end correction, and when calculating the natural frequency, not only the inside of the pipe but also the air around the opening vibrates additionally. This is corrected to the effective length L ′ instead of the actual measurement value L, and is determined by the shape of the hole 41.

  In Equation (1), ^ (1/2) represents the 1/2 power, that is, the square root.

  Equation (1) is similarly applied to the hole 42 and the hollow portion 52.

  According to the results of the experiment by the applicant, when the width of the hollow portion 51 and the air layer thickness L with respect to the side surface where the hole 41 is provided are multiplied by any value of 0.64 to 0.7 as a correction coefficient, the formula It was found that the resonance frequency f0 in (1) almost coincides with the actual resonance frequency. That is, about 70% of the volume of the hollow portion 51 or the hollow portion 52 acts as an air spring.

  From equation (1), in order to change the resonance frequency f0 from 100 Hz to 200 Hz by making the width or depth of the extruded material 21 easy to use and from 30 mm to 100 mm, the length of the hole 41 (neck length l) That is, the thickness of the side surface of the extruded material 21 in which the holes 41 are formed is preferably in the range of 4 mm to 7 mm. Since the extruded material 21 is made of recycled wood that has been extruded and is a wooden member, the thickness of the side surface can be easily obtained.

  With a material such as aluminum, it is difficult to secure the thickness of the side surface, and it is difficult to absorb a sound of 100 Hz to 200 Hz, which is a low frequency range. Moreover, it is difficult to absorb sound in a low frequency range of 200 Hz or less with a fibrous sound absorbing material such as glass wool.

  In the louver 11, by adopting the extrusion molding material 21 which is a wooden member, it becomes easy to obtain the thickness of the side surface, and it is possible to absorb sound of 100 to 200 Hz which is a low sound range. Further, in the louver 11, by adjusting the opening area of the hole 41 or 42 and the interval between the holes 41 or 42, it is possible to absorb a sound in a high frequency range of about 1 kHz or more. Thus, the louver 11 can absorb a wider range of sounds.

  By arranging the louver 11 so that the hole 41 faces the sound source, sound can be absorbed more effectively. Moreover, even if the louver 11 is arranged so that the hole 41 faces the opposite side of the sound source, the sound can be absorbed.

  Since the louver 11 absorbs sound, the sound generated from the sound source does not circulate to the sound source side (returns and does not reverberate), and becomes quieter. For example, if the sound is only shielded, the sound generated from the sound source circulates and reverberates toward the sound source, so that the sound becomes louder and noisy.

  In addition, you may make it form one rectangular parallelepiped hollow part inside the extrusion molding material 21. FIG.

  Further, the cross section of each of the holes 41 and 42 is not limited to a circular shape, as long as a predetermined opening area can be obtained. For example, an elliptical shape, an oval shape, or a rectangular shape may be used. You can also design a star or heart shape.

  Moreover, you may make it change the cross-sectional shape of each of the hole 41 and the hole 42, or the area of opening. For example, the shape of the cross section of each of the holes 41 and 42 may be changed depending on the depth from the side, such as so-called counterbore or deep counterbore processing.

  Although it has been described that each of the holes 41 and the holes 42 is provided on the side surface in the longitudinal direction of the extrusion molding material 21 so as to be arranged in a line in the longitudinal direction, the present invention is not limited thereto, and the two or three rows are provided. Arranging, arranging on a line that is bent many times in a Z-shape (so-called zigzag, lightning bolt shape), or arranging on a curve, can be arbitrarily arranged.

  Further, although it has been described that the holes 41 and the holes 42 are provided at equal intervals, the present invention is not limited to this, and even if two or three length intervals appear alternately, the intervals become longer in order. It can also be provided at an arbitrary interval such as the interval is changed.

  A hole 41 having a predetermined cross-sectional area that communicates with the hollow portion 51 may be provided on the left side surface in addition to the side surface on the back side. In this case, the holes 41 provided on the left side surface are provided at predetermined intervals in the longitudinal direction. That is, among the side surfaces in the longitudinal direction of the respective extruded molding materials 21, a plurality of holes 41 having a predetermined cross-sectional area that communicates with the hollow portion 51 and that are arranged at predetermined intervals in the longitudinal direction are provided on each of the plurality of side surfaces. Also good. For example, according to the displacement in the Z-axis direction, the holes 41 may be alternately provided on the side surface on the back side and the left side surface.

  Further, in the louver 11, the structure of each of the plurality of extrusion molding materials 21 may be changed. For example, in the louver 11, the extrusion material 21 in which the hole 42 is not provided on the left side surface and the hole 41 is provided in the side surface on the back side, and the hole 41 is not provided in the side surface on the back side. Alternatively, the extrusion molding material 21 provided with the holes 42 may be alternately arranged.

  Next, an example of the sound absorption characteristics of the louver 11 will be described with reference to FIGS. FIG. 10 is a diagram illustrating an example of transmission loss when the louver 11 is provided. 11 to 14 are diagrams showing examples of sound absorption rates when the diameters of the holes 41 and 42 which are round holes are changed and the distances between the holes 41 and 42 are changed.

  Note that the sound absorption characteristics shown in FIGS. 10 to 14 are the results of actual measurement at the Toyama Prefectural Industrial Technology Center.

  FIG. 10 shows a wall for blocking sound sources and sound, and when a wall having a square window is provided, transmission loss when nothing is provided in the square window, and a louver in the square window. It is a figure which shows the transmission loss when 11 is provided. In FIG. 10, the alternate long and short dash line indicates transmission loss when nothing is provided in the rectangular window, and the dotted line indicates that the diameter of the hole 41 and the hole 42 which are round holes is 7 mm, and the hole 41 and the hole 42 respectively. The solid line indicates the transmission loss when the diameter of the hole 41 and the hole 42, which are round holes, is 15 mm, and the distance between the hole 41 and the hole 42 is 25 mm. . In this case, the outer shape of the extrusion molding material 21 is 35 mm in width and 100 mm in depth. A hollow portion 51 and a hollow portion 52 each having a width of 27 mm and a depth of 44 mm are formed on the inner side of each of the extruded materials 21 so as to be aligned in the longitudinal direction of the side surface.

  As shown in FIG. 10, when the louver 11 is provided, a transmission loss greater than the transmission loss when nothing is provided in the rectangular window is obtained in the frequency band from 500 Hz to 8 kHz. That is, noise is attenuated in a frequency band from 500 Hz to 8 kHz.

  Compared to the case where nothing is provided in the rectangular window, when the diameter of the hole 41 and the hole 42 which are round holes is 7 mm and the interval between the hole 41 and the hole 42 is 25 mm, the dotted line in FIG. As shown, 1.5 dB or more at 630 Hz, 1.0 dB or more at 1.25 kHz, 1.5 dB or more at 2 kHz, 1.5 dB or more at 3.15 kHz, 1.0 dB or more at 4 kHz, 5 kHz In FIG. 1, the transmission loss increases at 1.0 dB or more at 1.5 dB or more and 6.3 kHz.

  Further, in comparison with the case where nothing is provided in the rectangular window, the diameter of the hole 41 and the hole 42 which are round holes is 15 mm, and the interval between the hole 41 and the hole 42 is 25 mm. As shown by the solid line, 3.0 dB or more at 1 kHz, about 2.0 dB at 1.25 kHz, 1.5 dB or more at 2 kHz, 1.5 dB or more at 3.15 kHz, 1.0 dB or more at 4 kHz The transmission loss increases at 1.5 dB or more at 5 kHz and 1.0 dB or more at 6.3 kHz.

  FIG. 11 shows the louver 11 when the sound absorption coefficient of a louver made of a member not provided with holes, the diameter of the holes 41 and 42 which are round holes is 2 mm, and the distance between the holes 41 and 42 is 50 mm. It is a figure which shows the sound absorption coefficient. In this case, the outer shape of the member and the extrusion molding material 21 is 35 mm in width and 100 mm in depth. Two hollow portions having a width of 27 mm and a depth of 44 mm, or a hollow portion 51 or a hollow portion 52 are formed on the inner side of each of the member and the extrusion molding material 21 so as to be aligned in the longitudinal direction of the side surface.

  In FIG. 11, the dotted line indicates the sound absorption coefficient of the louver made of a member not provided with a hole, and the solid line indicates that the diameter of the hole 41 and the hole 42 which are round holes is 2 mm, and the interval between the hole 41 and the hole 42 is defined as The sound absorption coefficient of the louver 11 in the case of 50 mm is shown.

  When the diameters of the hole 41 and the hole 42 which are round holes are 2 mm and the interval between the hole 41 and the hole 42 is 50 mm, the louver 11 resonates in the vicinity of 200 Hz and absorbs the sound in the vicinity of 200 Hz. In the vicinity of 200 Hz, the sound absorption coefficient of the louver 11 made of a member having no holes is about 0.125, whereas the sound absorption coefficient of the louver 11 exceeds 0.4.

  FIG. 12 shows a case where the sound absorption coefficient of a louver made of a member not provided with holes, the diameter of the round holes 41 and 42 is 4.5 mm, and the distance between the holes 41 and 42 is 50 mm. It is a figure which shows the sound absorption rate of the louver. In this case, the outer shape of the member and the extrusion molding material 21 is 35 mm in width and 100 mm in depth. Two hollow portions having a width of 27 mm and a depth of 44 mm, or a hollow portion 51 or a hollow portion 52 are formed on the inner side of each of the member and the extrusion molding material 21 so as to be aligned in the longitudinal direction of the side surface.

  In FIG. 12, the dotted line indicates the sound absorption coefficient of the louver made of a member not provided with a hole, and the solid line indicates that the diameter of the hole 41 and the hole 42, which are round holes, is 4.5 mm. The sound absorption coefficient of the louver 11 when the interval is 50 mm is shown.

  When the diameters of the hole 41 and the hole 42 which are round holes are 4.5 mm, and the interval between the hole 41 and the hole 42 is 50 mm, the louver 11 resonates in the vicinity of 400 Hz and absorbs sound in the vicinity of 400 Hz. . In the vicinity of 400 Hz, the sound absorption coefficient of the louver made of a member having no hole is about 0.05, whereas the sound absorption coefficient of the louver 11 exceeds 0.25.

  FIG. 13 shows the louver 11 when the sound absorption coefficient of a louver made of a member not provided with holes, the diameter of the holes 41 and 42 which are round holes is 7 mm, and the distance between the holes 41 and 42 is 25 mm. It is a figure which shows the sound absorption coefficient. In this case, the outer shape of the member and the extrusion molding material 21 is 35 mm in width and 100 mm in depth. Two hollow portions having a width of 27 mm and a depth of 44 mm, or a hollow portion 51 or a hollow portion 52 are formed on the inner side of each of the member and the extrusion molding material 21 so as to be aligned in the longitudinal direction of the side surface.

  In FIG. 13, the dotted line indicates the sound absorption coefficient of the louver made of a member not provided with a hole, and the solid line indicates that the diameter of the hole 41 and the hole 42 which are round holes is 7 mm, and the interval between the hole 41 and the hole 42 is set as the distance. The sound absorption coefficient of the louver 11 in the case of 25 mm is shown.

  When the diameters of the hole 41 and the hole 42 which are round holes are 7 mm and the interval between the hole 41 and the hole 42 is 25 mm, the louver 11 resonates around 800 Hz and absorbs sound around 800 Hz. In the vicinity of 800 Hz, the sound absorption coefficient of the louver 11 made of a member not provided with holes is about 0.16, whereas the sound absorption coefficient of the louver 11 exceeds 0.30.

  FIG. 14 shows the louver 11 when the sound absorption coefficient of a louver made of a member having no holes, the diameters of the holes 41 and 42 as round holes are 15 mm, and the distance between the holes 41 and 42 is 25 mm. It is a figure which shows the sound absorption coefficient. In this case, the outer shape of the member and the extrusion molding material 21 is 35 mm in width and 100 mm in depth. Two hollow portions having a width of 27 mm and a depth of 44 mm, or a hollow portion 51 or a hollow portion 52 are formed on the inner side of each of the member and the extrusion molding material 21 so as to be aligned in the longitudinal direction of the side surface.

  In FIG. 14, the dotted line indicates the sound absorption coefficient of a louver made of a member not provided with a hole, and the solid line indicates that the diameter of the hole 41 and the hole 42 which are round holes is 15 mm, and the interval between the hole 41 and the hole 42 The sound absorption coefficient of the louver 11 in the case of 25 mm is shown.

  When the diameters of the hole 41 and the hole 42 which are round holes are 15 mm and the interval between the hole 41 and the hole 42 is 25 mm, the louver 11 resonates around 1 kHz and absorbs sound around 1 kHz. In the vicinity of 1 kHz, the sound absorption coefficient of the louver 11 made of a member having no holes is about 0.14, whereas the sound absorption coefficient of the louver 11 exceeds 0.25.

  Thus, when the area of the opening of the hole 41 or the hole 42 and the interval between the holes 41 or the hole 42 are adjusted in accordance with the shape of the hollow part 51 or the hollow part 52, the louver 11 can resonate with Helmholtz resonance. Resonates at a predetermined frequency due to the effect, and absorbs the sound of the resonating frequency.

  11 to 14 show the sound absorption coefficient when the diameters of the holes 41 and 42, which are round holes, are constant, and the intervals between the holes 41 and 42 are constant. 21, the diameter of the hole 41 and the hole 42 or the distance between the hole 41 and the hole 42 is changed, or the diameter of the hole 41 and the hole 42 or the distance between the hole 41 and the hole 42 is changed for each extruded material 21. Thus, it is possible to resonate at a plurality of frequencies, and it is possible to absorb sound at each resonance frequency. That is, in this case, the louver 11 can absorb sound in a specific frequency band.

  In other words, by adjusting the opening area of the hole 41 or the hole 42 and the interval between the holes 41 or 42 according to the shape of the hollow part 51 or the hollow part 52, the sound absorption rate of the sound of a specific frequency is increased. Or a sound in a frequency band within a predetermined range can be absorbed.

  Thus, the louver 11 is composed of a plurality of extrusion molding materials 21 arranged at a predetermined gap. The extrusion molding material 21 is formed of a wooden member. The outer shape of the extrusion molding material 21 is formed in a rectangular parallelepiped shape. The thickness of the side surface in the longitudinal direction of the extrusion molding material 21 is formed within a predetermined range. A rectangular parallelepiped hollow portion is formed inside the extruded material 21. A plurality of holes 41 communicating with the hollow portion 51 are provided at predetermined intervals in the longitudinal direction on any of the side surfaces in the longitudinal direction of the respective extrusion molding materials 21.

  Longitudinal side surface of a wooden extruded product 21 having an outer shape formed in a rectangular parallelepiped shape, a thickness on a side surface in the longitudinal direction within a predetermined range, and a rectangular parallelepiped hollow portion formed inside. Since a plurality of holes 41 communicating with the hollow portion 51 are provided at predetermined intervals in the longitudinal direction, sound can be absorbed by the Helmholtz resonance effect with a simpler structure. Since a sound absorbing material such as a fibrous material is not required, the sound absorbing performance is not deteriorated by being wet with water, and the desired sound absorbing performance can be maintained even when used outdoors. That is, it is possible to absorb sound stably at a sound absorption level above a certain level. Since the plurality of extrusion molding materials 21 are arranged with a predetermined gap, air circulation can be ensured. Therefore, the desired sound absorbing performance can be maintained even when used outdoors with a simpler structure and ensuring air circulation.

  The hollow portion 51 is opened at the end in the longitudinal direction of the extruded material 21 with the cross-sectional shape of the hollow portion 51 being a constant cross-sectional shape in a plane orthogonal to the longitudinal side surface of the extruded material 21. Can do.

  By doing in this way, even if it uses outdoors, since rainwater flows out and rainwater does not accumulate, desired sound absorption performance can be maintained.

  The holes 41 can be provided on the side surface in the longitudinal direction of the extruded material 21 so as to be aligned in a row in the longitudinal direction. By doing in this way, it is easy to process and it can improve appearance.

  The holes 41 can be provided at equal intervals. By doing in this way, it is easy to process and it can improve appearance.

  The direction of the side surface in which the hole 41 in the one extrusion molding material 21 is provided in the plurality of extrusion molding materials 21 is set so that the hole 41 in the other extrusion molding material 21 in the plurality of extrusion molding materials 21 is provided. Can be the same as the side orientation. By doing in this way, construction is easy and the appearance can be improved.

  The side surface provided with the hole 42 in one of the plurality of extrusion molding materials 21 can be a side surface adjacent to the other extrusion molding material 21. By doing in this way, the hole 42 can be hidden and made inconspicuous and the freedom degree of design can be raised.

  A plurality of holes 41 having a predetermined cross-sectional area that communicates with the hollow portion 51 and that are arranged at predetermined intervals in the longitudinal direction can be provided on each of the plurality of side surfaces among the side surfaces in the longitudinal direction of the respective extrusion molding materials 21. By doing in this way, it is easy to process and it can improve appearance. In addition, the range of adjustment of sound absorption characteristics is widened.

  A hollow portion 51 and a hollow portion 52 that are two hollow portions arranged in the longitudinal direction of the side surface of the extrusion molding material 21 can be formed inside each extrusion molding material 21. By doing in this way, it becomes easy to make sound absorption and appearance compatible by providing the hole 41 or the hole 42 leading to at least one of the hollow part 51 or the hollow part 52.

  The cross-sectional shapes of the two hollow portions and the cross-sectional shapes in the plane orthogonal to the side surface in the longitudinal direction of the extrusion molding material 21 can be made substantially the same. By doing in this way, it becomes easy to determine the frequency of the sound to absorb and to process easily.

  The hole 41 and the hole 42 are provided on each of two side surfaces of the side surfaces in the longitudinal direction of the extrusion molding material 21, and the hole 41 provided on one side surface is provided with a plurality of hollow portions 51 and hollow portions. One of the portions 52 is communicated with one of the hollow portions 51, and the hole 42 provided on the other side surface is communicated with the hollow portion 51 that is a plurality of hollow portions and the other hollow portion 52 among the hollow portions 52. be able to. By doing in this way, it can absorb sound more effectively.

  The extruded material 21 can be formed from recycled wood. In this case, durability can be improved.

  The extruded material 21 can be extruded. In this case, since the hollow part 51 and the hollow part 52 can be formed more accurately, it is easier to absorb sound with desired characteristics.

  In addition, the extrusion molding material 21 can also be formed with concrete.

  The embodiments of the present invention are not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention.

11 louvers, 21 extruded materials, 41 and 42 holes, 51 and 52 hollow parts

Claims (12)

A wooden member having an outer shape formed in a rectangular parallelepiped shape, a thickness on a side surface in a longitudinal direction within a predetermined range, and a rectangular parallelepiped hollow portion formed therein, with a predetermined gap It consists of multiple members that are arranged,
A plurality of holes that communicate with the hollow portion are provided at predetermined intervals in the longitudinal direction on any of the longitudinal side surfaces of each of the members. The louver according to claim 1, wherein
A cross-sectional shape of the hollow portion, and a cross-sectional shape in a plane orthogonal to the side surface in the longitudinal direction of the member is constant,
A louver in which the hollow portion is open at an end portion in a longitudinal direction of the member. The louver according to claim 1, wherein
The holes are provided on the side surfaces of the member in the longitudinal direction so as to be aligned in a row in the longitudinal direction. The louver according to claim 1, wherein
The holes are provided at equal intervals. The louver according to claim 1, wherein
The direction of the side surface provided with the hole in one of the plurality of members is the same as the direction of the side surface provided with the hole in the other member of the plurality of members. louver. The louver according to claim 5, wherein
The side surface provided with the hole in one of the members is a side surface adjacent to the other member. The louver according to claim 1, wherein
Among the side surfaces in the longitudinal direction of each of the members, each of the plurality of side surfaces is provided with a plurality of holes with a predetermined cross-sectional area that are arranged at predetermined intervals in the longitudinal direction and communicate with the hollow portion. The louver according to claim 1, wherein
Two hollow portions arranged in the longitudinal direction of the side surface of the member are formed inside each of the members. The louver according to claim 8, wherein
The cross-sectional shape of two said hollow parts, Comprising: The cross-sectional shape in the surface orthogonal to the side surface of the longitudinal direction of the said member is substantially the same. The louver according to claim 8, wherein
The hole is provided on each of two side surfaces of the side surfaces in the longitudinal direction of the member,
The hole provided in one side surface leads to the one hollow portion of the plurality of hollow portions,
The hole provided in the other side surface communicates with the other hollow portion of the plurality of hollow portions. The louver according to claim 1, wherein
The member is a louver made of recycled wood. The louver according to claim 1, wherein
The member is extruded.