JPH0768821B2 - Muffling - Google Patents

Description

TECHNICAL FIELD The present invention relates to a silencing louver used for indoor ventilation or various ventilation parts.

(Prior art and problem to be solved) A gallery is used for ventilation inside a building, and is used for ventilation of indoors and outdoors, as well as for daylighting and rain protection. As for the shape, there are various shapes in addition to those in which a number of thin plates have a certain inclination and are attached in parallel at intervals.

By the way, since the gallery has an opening for allowing air to flow, outdoor noise easily enters the room through the opening of the gallery, and conversely, sound in the room easily leaks to the outside.
It has been confirmed by acoustic calculation that when the opening area of the wall exceeds 1% of the wall surface, the sound insulation effect of the wall becomes half or less of that when the wall is not installed. .

If the louver is attached in this way, the sound insulation effect will inevitably decrease, and ventilation and sound insulation will be contradictory functions, but both noise prevention and ventilation are required, such as when using an electric fan. In many cases, there is a demand for a sound-absorbing louver that can satisfy both sound insulation and ventilation.

FIG. 7 and FIG. 8 show a conventional example of a silencing louver having both a ventilation function and a sound insulation function. In the gallery shown in FIG. 7, a sound deadening elbow 3 in which a duct is bent into an L shape is attached to the outside of the wall surface 1 from an opening 2 provided in the wall surface 1 with the tip opening portion facing downward. A sound absorbing material 4 such as glass wool is attached to the inner wall surface of the sound deadening elbow 3. When passing through the muffling elbow 4, the noise inside and outside the room is reflected and attenuated by the sound absorbing material. By using this muffling elbow, you can mute about 15 to 20 phones.

In the example shown in FIG. 8, a box-shaped silencer box 5 is provided following the opening of the wall surface 1. Box-shaped mute box 5
Inside, the air ventilation passage is formed in a maze shape, and the sound absorbing material 4 is attached to the inner wall surface of the ventilation passage. In the sound deadening box 5, the sound is reflected by the sound absorbing material 4 many times and attenuated to be muted. For the opening of the wall surface 1, a breathable filter 6 or an ordinary jar is used. Reference numeral 7 is an opening on the rear side of the muffling box.

In the conventional gallery that has a sound insulation function in this way, a sound absorbing material is attached to the inside of the duct or box so that the sound absorbing material attenuates the sound. Therefore, there is a problem that the ventilation efficiency is poor because the air flow is blocked.

Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a sound deadening gallery having a novel structure that is excellent in ventilation function, has a high sound insulation effect, and is structurally simple. Is what you are trying to do.

(Means for Solving the Problems) The present invention has the following configuration in order to achieve the above object.

That is, in a ventilation part such as an opening provided on a wall surface, a plurality of gallery fins are provided in parallel with each other at intervals to form an eaves-like shape, and a plurality of ventilation paths are formed between the gallery fins. It is characterized in that the lengths of the ventilation passages are made different by changing the extension length of each gullari fin in order to muffle the sound that has passed through the phase interference. Further, it is effective that the lengths of the gallary fins provided adjacent to each other differ by a length that is an integral multiple of approximately 1/3 of the length of the reference ventilation passage.

(Operation) The lengths of the adjacent ventilation passages formed by the gallery fins are made different by changing the extension lengths of the gallery fins provided in parallel with each other in the openings such as the wall surface. Due to the action of the acoustic lens, the phases of the sounds passing through the ventilation passages of different lengths are adjusted at the opening end, and when emitted to the outside of the galleries, the sounds interfere with each other to be muted. As a result, the galleries provide sound insulation.

(Examples) Hereinafter, preferred examples of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is an explanatory view showing an embodiment of the silencing louver according to the present invention.

In the figure, reference numeral 1 is a wall surface to which a sound absorbing louver is attached, and 2 is an opening portion provided through the wall surface. Reference numeral 8 denotes a louver frame for attaching the sound absorbing louver to the wall surface 1, and reference numerals 10a, 10b, 10c, 10d and 10e denote louver fins formed of a flat plate having the same width as the opening 2. The gallary fins are provided such that their tips are inclined downward with respect to the wall surface 1 and are vertically extended at predetermined intervals so as to extend in parallel to each other in an "eave" shape. The upper part of the gallery fin is fixed to the gallery fin support frame 12 fixed to the gallery frame 8.

The gallary fin is an upper portion fixed to the gallary fin support frame 12 and is bent at a substantially right angle to extend a bent piece 14. Bent piece 14
The length of is the same for each galari fin. However,
The upper end of the glass fin 10a installed at the top is fixed to the glass fin support frame 12, and the bending piece 14 is not provided.

As described above, the gallery fins 10a, 10b, 10c, 10d, and 10e are provided with a predetermined space between the gallery fins to form an air passage. Four ventilation passages are formed by five sheets of gullari fins. The length of each gallary fin is set so as to sequentially increase from the uppermost gallary fin 10a to the lowermost gallary fin 10e. The length of these galari fins is effective for silencing,
It is set to a predetermined length. In the example, the lengths of the respective galari fins were set as follows.

That is, assuming that the length from the bent portion of the uppermost gallery 10a to the leading edge is l, the length of the second and later gallery 10 is the second gallery 10b: 4 / 3l and the third gallery 10c. : 2l The fourth galari fin 10d: 7 / 3l The fifth galari fin 10e: 3l.

The reason why the lengths of the gallary fins are set differently in this way is that the sound is silenced by the action of the acoustic lens when the sound passes through the ventilation passage.

FIG. 2 is an explanatory diagram showing the principle of silencing by utilizing the action of the acoustic lens. As shown in FIG. 2, when a sound wave is passed through the narrow conduits 16 and 18 set to have a constant length ratio, the phase of sound is converted due to the difference in conduit length. More specifically, a part of the sound wave is reflected toward the inside of the pipes 16 and 18 at the open ends of the pipes 16 and 18 ("Noise Countermeasure Handbook" edited by the Japan Society for Acoustic Materials, pages 386 to 387). (Showa
49))), due to the interaction with this reflected wave, conduit 16,
The phase of the sound passing through 18 is adjusted to 0 at its open end as shown in FIG. Therefore, if the pipe length is set appropriately, the phases of the sound waves that have passed through the pipes 16 and 18 can be reversed, and the sound can be silenced by the effect of phase interference. In order to change the phase to the opposite phase, it is sufficient to change the pipe length by 1/2 of the wavelength of the sound to be silenced,
In order to exert an effective silencing effect on noises containing various wavelengths, the pipe lengths are selected so that they differ by an integer multiple of approximately 1/3 of the reference pipe length. The sound absorption effect is obtained by performing phase interference on the sounds of various wavelengths contained in the noise centering on the sound of the wavelength corresponding to.

The gallary fins of the above embodiment were set so that the lengths of the gallary fins were changed according to the conditions for setting the opposite phase. By providing a plurality of gallary fins having different muffling conditions and different lengths, it is possible to exert an effect on noise including various wavelengths and to provide required air permeability.

The tip of each gallery may be slidable and extendable so that the length of the gallery can be finely adjusted. Further, if a sound absorbing material is attached to the inner wall surface forming the ventilation passage of each gullari fin, the sound deadening effect is further enhanced.

FIG. 3 is an explanatory diagram of the sound reduction function when the above-mentioned gallery is actually installed. As shown in the figure, the sound reduction effect when using the above-mentioned gallery is as follows: sound reduction effect A due to reflection and diffraction due to the folds of the gallery, and air passing through the ventilation passage to the outside. There are a sound reducing effect B due to the sound being diffracted at the emitted opening end, and a sound reducing effect C due to the phase interference due to the above-mentioned difference in pipe length.

FIG. 4 is a cross-sectional view showing an installation example of the above-mentioned gallery fins. It should be noted that FIG. 5 shows a conventional type installation example in which a sound deadening box is attached as a comparative example.

In FIG. 4, reference numeral 20 denotes a gallary fin, and a thin box 24 having a sound absorbing material 22 attached to the inner surface thereof is provided at the rear part of the ventilation passage of the gallary fin. 26 is a ventilation port. Galariffin in this example
The glass fins are arranged so that the tip positions of the openings 20 are aligned. In the figure, the design value of the opening a of the gullary fin is 600 mm, and the length b of the inclined portion is 120 mm. In FIG. 5, 28 is a conventional type louver provided in the opening, and 30 is a muffler box in which the ventilation passage is formed in a labyrinth shape. 32 is a pillar.

Comparing FIG. 4 and FIG. 5, the use of the silencing louver of this embodiment is characterized in that it is formed much thinner than the conventional louver.

FIG. 6 is a sound reduction characteristic graph obtained by measuring the sound reduction effect of the silencing louvers shown in FIG. In this characteristic graph, the vertical axis represents the volume reduction for sounds of different frequencies. According to the muffling louver of the example, the sound reduction effect of 10 to 20 phones was obtained.

As described above, in the gallery of this embodiment, it was confirmed that effective sound reduction can be achieved by using gallery fins of different lengths. In addition, this muffling louver only has ventilation passages of different lengths, and therefore has the characteristic that the air flow does not change and sufficient air permeability is obtained. As a result, a gallery having ventilation and effective sound insulation can be obtained.

In addition, the above-mentioned configuration in which the effect of phase interference is used by making the passage lengths different can be applied to various ventilation or ventilation passages. For example, when attached to an electric fan, the ventilation performance is good. As a result, energy saving can be achieved, and at the same time, both effects of preventing noise generated from the fan can be achieved. In addition, it can be provided in the intake / exhaust port portion of an air conditioner such as a cooler, etc., so that ventilation and noise can be effectively prevented.

Further, since the silencing louver of this embodiment can exhibit the effect in a thin shape as compared with the conventional silencing box, there is also an advantage that it can be attached to a portion having a small installation space.

In the above embodiment, an example was shown in which the gallary fins were fixed to the gallary fin support frame 12 at a predetermined angle in advance, but the gallary fins rotate about the upper end fixed to the gallary fin support frame 12 while keeping them parallel to each other. It can also be movably provided. If you make it movable like this,
It can be opened only when it needs to be ventilated, or it can be attached to an electric fan so that it can only be opened when the electric fan is activated.

Although the present invention has been variously described above with reference to the preferred embodiments, the present invention is not limited to these embodiments.
Of course, many modifications can be made without departing from the spirit of the invention.

(Effect of the Invention) According to the present invention, as described above, by changing the extension length of each gallery fin, the length of the ventilation passages formed between these gallery fins is different from each other. Depending on the structure, an effective sound deadening effect can be obtained, and at the same time, sufficient ventilation can be obtained because it does not hinder the flow of air.

In addition, since the louver can be made thin, it can be installed in a small space, which is very effective.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an embodiment of a silencing louver according to the present invention, FIGS. 2 and 3 are explanatory views showing a silencing action, and FIG.
Fig. 5 is a cross-sectional view showing an example of installation of the noise reduction gallery, Fig. 5 is a cross-sectional view showing a comparative example of the noise reduction gallery, Fig. 6 is a graph showing the noise reduction effect of the installation example, and Figs. 7 and 8 are conventional It is sectional drawing which shows the example of a silencing louver. 1 ... wall surface, 2 ... opening, 3 ... silence duct, 4 ...
Sound-absorbing material, 5 ... muffling box, 6 ... filter, 8 ...
Glass frame, 10a, 10b, 10c, 10d, 10e …… Galari fin, 12 …… Galari fin support frame, 14 …… Bending piece, 16, 18
…… Pipeline, 20 …… Galarifin, 22 …… Sound absorbing material, 24 ……
Box, 26 ... Vent, 28 ... Rattle, 30 ... Silent box, 32 ... Pillar.

Claims (2)

[Claims] 1. A ventilation part such as an opening provided on a wall surface,
A plurality of gallery fins are provided in parallel with each other at intervals to form an eaves-like shape, and in a gallery that forms a plurality of ventilation paths between these gallery fins, in order to mute the sound passing through the adjacent ventilation paths by phase interference, A silencing louver characterized in that the lengths of the ventilation passages are made different by changing the extension lengths of the louver fins. 2. The muffler according to claim 1, wherein the lengths of the gallary fins provided adjacent to each other differ by a length that is an integral multiple of about 1/3 of the reference length of the ventilation passage. A gallery.