JP7469986B2 - Background noise generator - Google Patents

Description

The present invention relates to a background noise generating device that generates background noise indoors to counteract everyday life sounds from outside the room.

In recent apartment buildings and other shared housing, the level of sound entering the building from outside has been reduced due to high insulation and airtightness, and in residential areas, the A-weighted sound pressure level inside the building at night can reach the low 20 dB range.
In this way, in an environment where the level of sound entering the building from outside is low, the problem arises that the sounds of daily life from outside can be heard and become bothersome inside the building. Note that "sounds of daily life from outside" refers to sounds of daily life from upper floors or neighboring residences in an apartment building, sounds of daily life from neighboring houses in a detached building, etc.
A method is known in which a resistance device is installed inside an air intake hole formed in the exterior wall of a building, and background noise (overall noise other than the target noise that occurs in the surrounding environment of the target noise) is generated to increase the volume of sound that flows into the room through the air intake hole, thereby creating an indoor environment in which it is difficult to hear everyday sounds from outside (see Patent Document 1, etc.).

JP 2018-136091 A

However, the above-mentioned method involves generating background noise by installing a resistor inside an air intake hole formed in the exterior wall of a building, and therefore has the problem that it cannot be used in rooms that do not have an air intake hole facing the exterior wall.
To provide a background noise generating device that can realize an indoor environment in which living sounds from outside are difficult to hear, even in a room that does not have an air intake opening facing an exterior wall.

The background noise generating device of the present invention comprises an air intake hole provided in the ceiling, floor or partition wall of a room for supplying air to the room from the space above the ceiling, the space under the floor or the space within the wall, and a resistance device that provides resistance when air passes inside the air intake hole , the resistance device comprising a cylinder formed with an outer diameter that corresponds to the inner diameter of the cylinder of the cylindrical part that forms the air intake hole and installed inside the air intake hole, a cross-shaped resistance plate provided on one opening end of the cylinder, and a circular resistance plate provided on the other opening end of the cylinder, the cross-shaped resistance plate being positioned on the inside of the side of the air intake hole closer to the room, and the circular resistance plate being positioned on the inside of the side of the air intake hole farther from the room, thus making it possible to realize an indoor environment in which it is difficult to hear living sounds from outside, even in a room that does not have an air intake hole facing the exterior wall, and making it possible to increase the volume of the sound when air flows into the room through the air intake hole.
The cross-shaped resistance plate is a cross-shaped plate with slits formed on the inside of the cross-shaped plate whose diameter corresponds to the diameter of the inner peripheral surface of the cylinder, and the slits are formed in the center of each of the four plate parts along the extension direction of each of the four plate parts protruding in all directions from the central plate part of the cross. The circular resistance plate is formed based on a circular plate whose diameter corresponds to the diameter of the inner peripheral surface of the cylinder, a circular hole is formed in the center of the circular plate, and four parts on the outer periphery of the circular plate separated by 90° from each other with the center of the circular plate as a reference are left as connection parts, and the circular plate the outer periphery of the cylinder is removed along the outer periphery to form a circular outer periphery, and four portions spaced 90° from each other with respect to the center of the circular hole are left as four plate portions continuing from the connecting portions and extending toward the center of the circular hole, and an arc-shaped slit centered on the center of the circular hole is formed in the arc-shaped plate portion between adjacent plate portions in the circumferential direction, and an outermost periphery slit is formed by the space between the circular outer periphery and the inner periphery of the cylinder, thereby making it possible to increase the volume of the sound when air flows into the room through the air intake hole.
In addition, the resistance device is characterized in that the slit width of the outermost circumferential slit is configured to be changeable, making it possible to adjust the volume of the sound when air flows into the room through the air intake hole.
In addition, the resistance device is characterized by being configured such that the four plate portions of the cross-shaped resistance plate and the four plate portions of the circular resistance plate are arranged so as to face each other but are shifted circumferentially, or such that the four plate portions of the cross-shaped resistance plate and the four plate portions of the circular resistance plate are arranged so as to face each other directly, thereby making it possible to increase the volume of sound when air flows into the room through the air intake hole.In particular, by configuring the four plate portions of the cross-shaped resistance plate and the four plate portions of the circular resistance plate so as to face each other but are shifted circumferentially, it is possible to further increase the volume of sound when air flows into the room through the air intake hole.
In addition, the resistance device is characterized in that the distance between the cross-shaped resistance plate and the circular resistance plate is adjustable, making it possible to adjust the volume of the sound when air flows into the room through the air intake.

FIG. 1 is a cross-sectional view showing an example of a building that employs a background noise generation method. FIG. 1 is a floor plan showing an example of a building in which the background noise generation method is used. FIG. FIG. 1 is a perspective view showing a resistance device; 3A and 3B are front and rear views showing a resistance device. 1A is a perspective view, a front view, and a rear view of a resistance device; FIG. 13 shows the experimental results of Experiment 1. FIG. 13 shows the experimental results of Experiment 2. FIG. 13 shows the experimental results of Experiment 3.

EMBODIMENT 1
The background noise generation method of embodiment 1, as shown in FIG. 1 , is a method for generating background noise in a building configured to supply air taken into building 10 from outside to rooms 12 within building 10 via attic space 11S, for example, in a building 10 that employs a first type ventilation system as a 24-hour ventilation system in which outside air is forcibly supplied to the interior of building 10 from outside and forcibly exhausted from the interior of building 10 to the outside of building 10. The method comprises providing a resistance device 2 inside air supply hole 1 provided in ceiling 11 of room 12 to provide resistance to the air passing through, thereby increasing the volume of the sound when air flows into room 12 through air supply hole 1, thereby realizing an indoor environment in which it is difficult to hear everyday sounds from outside, even in a room 12 that does not have an air supply hole facing the exterior wall 9 of building 10.

As shown in Figures 1 and 2, in a building 10 such as an apartment building (condominium) that employs a Type 1 ventilation method of a 24-hour ventilation system, air is forcibly taken in from the outside of the building 10 into the building 10, distributed to each room 12, 12... inside the building 10, and the air is forcibly exhausted from a specific location to the outside of the building 10.
Therefore, in the background noise generation method of embodiment 1, in order to distribute air taken in from outside the building 10 to the interior of the building 10 to each of the multiple rooms 12, 12... within the building 10, air intakes 1, 1... are provided in the ceilings 11, 11... of each of the multiple rooms 12, 12..., and resistance devices 2, 2... are provided inside each of the air intakes 1, 1....
For example, as shown in Figures 1 and 2, a building 10 is equipped with an air supply means 13 that takes in outside air from outside the building 10 into the building 10, a heat exchange system 14, an internal air intake hole 17 provided in the ceiling 11 of a specific room (e.g. a bedroom), air supply holes 1, 1... provided in the ceilings 11, 11... of each room 12, 12..., resistance devices 2, 2... provided inside each air supply hole 1, 1..., and an exhaust means 15 that exhausts air inside the building 10 to the outside of the building 10.

The air supply means 13 is a means for taking in outside air into the attic space 11S, which includes, for example (not shown) a through hole formed in the exterior wall 9 of the building 10, a cylinder that is fitted into the through hole to form an outside air intake hole, and a forced air supply means such as an air supply fan provided on the other end opening side of the cylinder that is closer to the heat exchange system 14.

2, the heat exchange system 14 is a device that performs a heat exchange process between outside air taken in from outside the building 10 by the air supply means 13 and inside air taken in from a specific room (e.g., a bedroom), and then distributes and supplies the air after the heat exchange process to each of the rooms 12, 12.... The heat exchange system 14 may be one that has an air cleaning function in addition to a heat exchange function.
In the plan view (floor plan) of the building 10 in FIG. 2, E is the entrance, Cd is the corridor, BR is the bedroom, UB is the bathroom with toilet, W is the washroom, K is the kitchen, WR is the Western-style room, C is the closet, JR is the Japanese-style room, and LD is the living-dining room.

As shown in FIG. 3, the air supply hole 1 is formed by an inner through hole 1H having a circular cross section in a cylindrical part 1A attached to the ceiling 11 so as to pass through a through hole 11a formed in the ceiling plate.
A mounting flange 1F is provided on the edge of one opening (lower opening) 1a of the cylindrical part 1A. The cylindrical part 1A is inserted through the through hole 11a from the other opening (upper opening) 1b, and the upper surface of the mounting flange 1F is brought into close proximity with the lower surface of the ceiling board. Then, for example, a screw or bolt is inserted through the mounting flange 1F and the ceiling board and fastened to a ceiling base (not shown), thereby attaching the cylindrical part 1A to the ceiling 11, and an air supply hole 1 that communicates between the room 12 and the ceiling space 11S is provided in the ceiling 11.
In addition, it is preferable that a lid 1E equipped with an opening/closing body 1R, such as a louver opening/closing part, for opening and closing the one end opening 1a of the cylindrical part 1A (the room side opening of the air intake hole 1) 1a be removably attached to the one end opening 1a side of the cylindrical part 1A.

The exhaust means 15 is a means configured to exhaust air from inside the building to the outside, and includes, for example, a through hole formed in the ceiling of a specific room 12 (e.g., a bathroom or washroom), a cylinder that is fitted into the through hole to form an internal air exhaust hole, and a forced exhaust means such as an exhaust fan provided on the opening side of the cylinder located in the ceiling space, etc., although not shown.

As shown in FIGS. 1 and 2, an outside air outlet (the other end opening of the above-mentioned cylinder) 13a of the air supply means 13 and an outside air intake 14a of the heat exchange system 14 are connected by a duct 16A.
2, the inside air intake 14b of the heat exchange system 14 and an opening on the underside of the ceiling of the inside air intake hole 17 provided in the ceiling 11 of the specific room 12 (e.g., a bedroom) are connected by a duct 16B. Note that it is sufficient that there is one or more specific rooms, and that there is also sufficient that there is one or more inside air intake holes 17.
As shown in Figures 1 and 2, the treated air discharge outlet 14c of the heat exchange system 14 is connected to each of the under-ceiling openings (the other end opening (upper end opening) 1b of the cylindrical part 1A mentioned above) of each air supply hole 1, 1... provided in each ceiling 11, 11... of each room 12, 12... by ducts 16C, 16C....

In addition, an air supply fan is provided near the outside air intake 14a and the inside air intake 14b of the heat exchange system 14, and an exhaust fan is provided near the treated air outlet 14c of the heat exchange system 14.

Therefore, the outside air taken in from the outside of the building 10 to the inside of the building 10 by the air supply means 13 is taken in by the heat exchange system 14 via the duct 16A and the outside air intake 14a arranged in the ceiling space 11S. Also, the inside air of a specific room 12 (for example, a bedroom) is taken in by the heat exchange system 14 via the inside air intake holes 17 arranged in the ceiling 11, the duct 16B arranged in the ceiling space 11S, and the inside air intake 14b. Then, the heat exchange system 14 performs a heat exchange process between the outside air and the inside air, and the air after this heat exchange process is distributed and supplied to each room 12, 12... via the treated air outlet 14c, the ducts 16C, 16C..., the air supply holes 1, 1... arranged in each ceiling 11, 11... of each room 12, 12..., and the resistance devices 2, 2... arranged in each air supply hole 1, 1....

In addition, in the first type ventilation method of the 24-hour ventilation system, the amount of air taken in from outside the building 10 to inside the building 10 by the air supply means 13 is adjusted to be equal to the amount of air exhausted from inside the building 10 to outside the building 10 by the exhaust means 15.

The background noise generating device used in the background noise generating method according to embodiment 1 is configured as shown in FIG. 3 to include an air supply hole 1 provided in the ceiling of room 12 to supply air from the ceiling space 11S side to room 12, and a resistance device 2 that provides resistance to the air passing inside the air supply hole 1.

As shown in Figure 4, for example, the resistance device 2 comprises a cylinder 21 formed with an outer diameter corresponding to the inner diameter of the cylindrical part 1A forming the air supply hole 1 (i.e., the hole diameter of the inner through hole 1H), and a cross-shaped resistance plate 22 and a circular resistance plate 23 as resistance plates provided near the openings at both ends of the cylinder 21.
The cross-shaped resistance plate 22 is a resistance plate that, when attached to the one end opening 21a side of the cylinder 21 and installed in the air supply hole 1, is positioned on the one end opening 1a side to which the flange 1F of the cylindrical part 1A is attached.
The circular resistance plate 23 is a resistance plate that, when attached to the other end opening 21b side of the cylinder 21 and installed in the air supply hole 1, is positioned on the other end opening 1b side of the cylindrical part 1A where there is no flange 1F.

As shown in Figures 4 and 5(a), the cross-shaped resistance plate 22 is, for example, a cross-shaped plate with a slit, that is, a cross-shaped plate having a predetermined plate thickness (for example, a plate thickness of about 0.1 mm to 2 mm) and a diameter dimension corresponding to the diameter dimension of the inner surface of the cylinder 21, and a slit (a through hole that penetrates the plate) 24 formed on the inside of the cross-shaped plate.
The slits 24 are formed in the center of each of the four plate portions 26, 26... that protrude in all four directions from a central plate portion 25 of the cross along the extension direction of each of the four plate portions 26, 26....
The extended ends of each of the four plate portions 26, 26... are connected to the inner surface of the one end opening 21a of the cylindrical body 21 or to the opening edge of the one end opening 21a of the cylindrical body 21 by connecting means such as welding, adhesive, screwing, engagement means, etc.

As shown in Figures 4 and 5 (b), the circular resistance plate 23 is formed, for example, based on a circular plate with a predetermined plate thickness (for example, about 0.1 mm to 2 mm) and a diameter dimension corresponding to the diameter dimension of the inner peripheral surface of the cylinder 21. That is, a circular hole is formed in the center of the circular plate, and the outer peripheral edge of the circular plate is removed by about several mm along the outer circumference, leaving four parts on the outer circumference of the circular plate separated by 90° from each other with the center of the circular plate as connection parts 31, and a circular hole 33 is formed inside the circular plate with the center at the center of the original circular plate, and further, a plurality of arc-shaped slits 34, 35, 38 are formed around the outer circumference of the circular hole 33. This is a circular plate with concentric arc-shaped slits.

Between the circular outer peripheral edge 32 and the circular hole 33, four portions spaced 90° from each other with the center of the circular hole 33 as the reference are left as four plate portions 36, 36... which are continuous with the connection portion 31 and extend toward the center of the circular hole 33, and arc-shaped slits 34, 35, 38 centered on the center of the circular hole 33 are formed in the arc-shaped plate portions 37, 37... between circumferentially adjacent plate portions 36 and 36.
The outermost periphery slit 38 formed on the outermost side of the circular resistance plate 23 is a slit whose slit width is the distance between the circular outer periphery 32 and the inner periphery surface of the cylinder 21. In other words, the outermost periphery slit 38 is formed by the space between the circular outer periphery 32 and the inner periphery surface of the cylinder 21.
The slits 34, 34... formed in each of the four plate portions 36, 36... are arc-shaped slits formed along a circumference of a predetermined radius centered on the center of the circular hole 33.
The slits 35, 35... formed in each of the four plate portions 36, 36... are arc-shaped slits formed along a circumference having a radius greater than the above-mentioned specified radius and centered at the center of the circular hole 33.

Then, each of the four connection portions 31, 31... is connected to the inner surface on the other end opening 21b side of the cylinder 21 or to the opening edge of the other end opening 21b of the cylinder 21 by connecting means such as welding, adhesive, screwing, engaging means, etc., so that arc-shaped outermost slits 38, 38... are formed between the inner surface of the cylinder 21 and the circular outer periphery 32 of the circular resistance plate 23.
That is, the circular resistance plate 23 is configured to have arc-shaped slits 34, 35, 38 formed in order from the side closest to the center of the circular hole 33, that is, it is a slitted circular plate provided with a plurality of concentric arc-shaped slits 34, 35, 38.

The resistance device may be a resistance device 2 (hereinafter referred to as an axial cross type) in which the plate portions 26, 26... of the cross-shaped resistance plate 22 and the plate portions 36, 36... of the circular resistance plate 23 are arranged to face each other with a circumferential shift, as shown in Figures 4 and 5, or a resistance device 2A (hereinafter referred to as an axial facing type) in which the plate portions 26, 26... of the cross-shaped resistance plate 22 and the plate portions 36, 36... of the circular resistance plate 23 are arranged to face each other directly, as shown in Figure 6, in which the plate portions 26, 26... of the cross-shaped resistance plate 22 and the plate portions 36, 36... of the circular resistance plate 23 are not arranged to face each other directly, as shown in Figure 6.

The resistance device 2 or resistance device 2A is installed inside the cylindrical part 1A and attached to the cylindrical part 1A by an attachment means such as welding, adhesive, screwing, engagement means, etc. so that the cross-shaped resistance plate 22 is positioned on the one end opening 1a side where the flange 1F of the cylindrical part 1A forming the air supply hole 1 is attached, and the circular resistance plate 23 is positioned on the other end opening 1b side where the flange 1F of the cylindrical part 1A is not attached.
The cylindrical part 1A with the resistance device 2 attached to its inside is attached to the ceiling 11 as described above so that the cross-shaped resistance plate 22 is positioned on the side closer to the room 12 and the circular resistance plate 23 is positioned on the side farther from the room 12, i.e., on the attic space 11S side, thereby attaching the background noise generating device to the ceiling 11 of the room 12.

According to the background noise generating method using the background noise generating device of embodiment 1, when air is distributed and supplied from heat exchange system 14 to each of rooms 12, 12... via ducts 16C, 16C... and each of the air intakes 1, 1... provided in each of the ceilings 11, 11... of each of the rooms 12, 12..., sound is generated due to resistance, etc. when the air passes through the resistance device 2 or resistance device 2A provided in each of the air intakes 1, 1.... In other words, the volume of sound when air flows into room 12 via the air intakes 1 and resistance device 2 can be increased.
Therefore, an indoor environment in which outside living sounds are hard to hear can be realized even in a room 12 that faces the outer wall 9 of the building 10 and has no air supply hole. Also, an indoor environment in which outside living sounds are hard to hear can be realized for each of a plurality of rooms 12, 12....
In addition, by adopting the first type ventilation system as the ventilation system for the building, ventilation can be smooth, and an indoor environment can be achieved in room 12 in which living sounds from outside are difficult to hear.

First, when the air from the heat exchange system 14 passes through the arc-shaped slits 34, 35, 38 of the circular resistance plate 23, it collides with each of the arc-shaped plate sections 37, 37... and each of the plate sections 36, 36..., generating sound. Furthermore, when the air from the heat exchange system 14 passes through the circular hole 33, its speed increases, and at this increased speed it collides with the cross-shaped resistance plate 22, generating sound, so the sound of the air flowing into the room 12 becomes louder.

In order to confirm the effect of the background noise generating device of the first embodiment, the following experiment was carried out.
Experiment 1
An experiment to verify the relationship between A-weighted sound pressure level and air volume by changing the slit width of the outermost peripheral slit 38 of the circular resistance plate 23.
Experiment 2
An experiment to verify how the A-weighted sound pressure level changes when the distance between the cross-shaped resistance plate 22 and the circular resistance plate 23 is changed.
Experiment 3
An experiment to verify the A-weighted sound pressure level and 1/3 octave band sound pressure level for the above-mentioned crossed axis type and directly opposed axis type.

- Experimental method A ceiling model simulating a ceiling was installed in an anechoic chamber, a cylinder was pierced through the ceiling model to form an air inlet 1, and a resistance device 2 (axial cross type) or resistance device 2A (axial facing type) was installed in the air inlet 1 so that a cross-shaped resistance plate 22 was located on one opening side of the air inlet 1 and a circular resistance plate 23 was located on the other opening side of the air inlet 1, and an experimental device was fabricated that passes air from the other opening side of the air inlet 1 to the one opening side, and differences in effect due to differences in test specimens of resistance device 2 were verified. In the experiment, a sealed box was provided on the back side of the ceiling model surrounding the other opening side of the air inlet 1, and this sealed box and the blower fan were connected by a duct of about 20 m, and a sound-proof box was installed midway through the duct, so that the blower fan was configured to blow air to resistance device 2 inside the sealed box so that the sound generated by the blower fan would not be measured.
In measuring the A-weighted sound pressure level and the 1/3 octave band sound pressure level, the center position of the head case of the microphone was fixed at a position 1 m away from the center position of one end opening of the air inlet 1 .
Then, the blower fan was driven and the sound pressure level of the sound generated when the wind passed through the resistance device 2 was measured.
Since the operating noise is a steady sound, the equivalent sound pressure level was determined for 20 seconds.
The ventilation volume was measured using an airflow meter.

In experiment 1, an axial cross type resistance device 2 was used. The outer diameter of the cylindrical body 21 of the resistance device 2 was 90 mm, and the diameter of the circular hole 33 of the circular resistance plate 23 was 40 mm. Test specimen S without the resistance device 2 (not equipped with the resistance device 2), test specimen 1 with the slit width of the outermost periphery slit 38 of 1 mm, test specimen 2 with the slit width of the outermost periphery slit 38 of 3 mm, test specimen 3 with the slit width of the outermost periphery slit 38 of 5 mm, and test specimen 4 with the slit width of the outermost periphery slit 38 of 10 mm were used to verify how the A-weighted sound pressure level changes when the airflow passing through is changed for each test specimen.

The results of Experiment 1 are shown in FIG.
The results of Experiment 1 revealed the following trends.
(1) When the width of the slit 38 is reduced, the generated sound (A-weighted sound pressure level) increases.
(2) As the air volume increases, the A-weighted sound pressure level increases.

In experiment 2, an axial cross type resistance device 2 and an axial facing type resistance device 2A were used, in which the outer diameter of the cylinder 21 was 90 mm, the diameter of the circular hole 33 of the circular resistance plate 23 was 40 mm, and the slit width of the outermost peripheral slit 38 was 3 mm. In each type of resistance device, the distance between the cross resistance plate 22 and the circular resistance plate 23 was changed to 10 mm, 20 mm, 30 mm, and 40 mm, and the A-weighted sound pressure level was measured to verify how the A-weighted sound pressure level changed due to the difference in the distance.

The results of Experiment 2 are shown in FIG.
The results of Experiment 2 revealed the following trends.
(1) The volume of the generated sound changes by changing the distance between the cross-shaped resistance plate 22 and the circular resistance plate 23; narrowing the distance increases the volume of the generated sound.

In experiment 3, an axial cross type resistance device 2 and an axial facing type resistance device 2A were used, in which the outer diameter of the cylinder 21 was 90 mm, the diameter of the circular hole 33 of the circular resistance plate 23 was 40 mm, and the slit width of the outermost peripheral slit 38 was 3 mm. In the axial cross type, the distance between the cross-shaped resistance plate 22 and the circular resistance plate 23 was 10 mm in test specimen 1, 20 mm in test specimen 2, 30 mm in test specimen 3, and 40 mm in test specimen 4. In the axial facing type, the distance between the cross-shaped resistance plate 22 and the circular resistance plate 23 was 10 mm in test specimen 5, 20 mm in test specimen 6, 30 mm in test specimen 7, and 40 mm in test specimen 8. The 1/3 octave band sound pressure level was measured for each test specimen.

The results of Experiment 3 are shown in FIG.
The results of Experiment 3 revealed the following trends.
(1) The noise generated by the axial cross type resistance device 2 is louder when the gap between the cross-shaped resistance plate 22 and the circular resistance plate 23 is narrow.

EMBODIMENT 2
In the first embodiment, a background noise generating device has been exemplified in which a resistance device including a cylinder 21, a cross-shaped resistance plate 22, and a circular resistance plate 23 is installed inside the air inlet 1, but the background noise generating device may also be configured in such a way that the cross-shaped resistance plate 22 and the circular resistance plate 23 are directly attached to the inside of the cylindrical part 1A that forms the air inlet 1. In other words, the background noise generating device may be configured in such a way that the cross-shaped resistance plate 22 is attached to the inside of one end opening 1a side where the flange 1F is attached of the cylindrical part 1A that forms the air inlet 1, and the circular resistance plate 23 is attached to the inside of the other end opening 1b side where the flange 1F is not attached of the cylindrical part 1A that forms the air inlet 1.

EMBODIMENT 3
Taking into consideration the above-mentioned Experiment 1, in embodiment 3, a background noise generating device is provided that is capable of changing the slit width of the outermost peripheral slits 38 of the circular resistance plate 23. That is, in order to make it possible to change the distance between the inner peripheral surface of the cylinder 21 or the inner peripheral surface of the cylindrical part 1A that forms the air inlet 1 and the circular outer peripheral edge 32, a plurality of types of circular resistance plates 23 are provided that are formed with different distances from the center of the circular hole 33 to the circular outer peripheral edge 32, and these plurality of types of circular resistance plates 23 are configured to be detachable from the cylinder 21 or the air inlet 1.
According to the background noise generating device of embodiment 3, it is possible to provide a background noise generating device that can adjust the volume of the sound when air flows into room 12 through air intake 1, i.e., the volume of the generated background noise, by adjusting the slit width of the outermost peripheral slits 38.

EMBODIMENT 4
Taking into consideration the above-mentioned Experiments 2 and 3, a background noise generating device was constructed in which the distance between the cross-shaped resistance plate 22 and the circular resistance plate 23 was made variable.
According to the background noise generating device of embodiment 4, by adjusting the distance between the cross-shaped resistance plate 22 and the circular resistance plate 23, it is possible to provide a background noise generating device that can adjust the volume of the sound when air flows into the room 12 through the air intake 1, i.e., the volume of the generated background noise.

In the embodiment, an example in which the background noise generating device and the inside air intake hole are provided on the ceiling has been shown, but the background noise generating device and the inside air intake hole 17 may be provided on the floor. In this case, the air supply means, the heat exchange system, the ducts, etc. may be provided in the space under the floor.
That is, in a building configured so that air taken in from outside the building is supplied to a room through an air supply hole provided in the floor, a resistance device is provided inside the air supply hole to provide resistance to the air passing through, thereby increasing the volume of the sound when air flows into the room through the air supply hole, and the background noise generating device used in this background noise generating method may be configured to include an air supply hole provided in the floor of the room for supplying air into the room from the underfloor space, and a resistance device that provides resistance to the air passing inside the air supply hole.

Further, the background noise generating device and the inside air intake hole 17 may be provided in a partition wall having an inner space. In this case, the ducts and the like may be provided in the inner space.
That is, in a building configured so that air taken in from the outside of the building is supplied to a room through an air supply hole provided in a partition wall, a resistance device is provided inside the air supply hole to provide resistance to the air passing through, thereby providing a background noise generation method that increases the volume of the sound when air flows into the room through the air supply hole, and the background noise generating device used in this background noise generation method may be configured to include an air supply hole provided in the partition wall of the room for supplying air to the room from the intra-wall space side, and a resistance device that provides resistance to the air passing inside the air supply hole.

Also, a resistance device may be provided in the inside air intake 17 to form a background noise generating device.
The material of the resistor device is not particularly limited, and the resistor device may be made of, for example, synthetic resin, metal, or the like.

The heat exchange system and the duct may be omitted.
In this case, either or both of the forced air supply means and the forced exhaust means may be omitted.
In such a case, an air supply fan can be installed in the air supply hole 1 to supply air from outside the building through the attic space, under-floor space, and space within the walls into the room.

In addition, in the embodiment, an example is shown in which an air intake hole is provided in the ceiling of each of the rooms in the building and a resistance device is provided inside each air intake hole in order to distribute the air taken in from the outside of the building to each of the rooms in the building, but it is not necessary to have a configuration in which air is distributed to each of the rooms in the building. In other words, it is sufficient to provide an air intake hole in the ceiling, floor, or partition wall of a specific room in the building and provide a resistance device inside the air intake hole that acts as a resistance to the air passing through, thereby increasing the volume of the sound when air flows into the room through the air intake hole.

The cylinder of the air supply means 13, the cylindrical part 1A forming the air supply hole 1, and the cylinder of the exhaust means 15 described above do not necessarily have to be cylindrical, and may be, for example, a square cylinder or other cylindrical body.

The resistance device may also be configured with only one of a circular resistance plate or a cross-shaped resistance plate.

The resistance device can be of any configuration as long as it provides resistance when air passes inside the air intake hole.

In addition, in the embodiment, an apartment building or other shared housing unit is used as an example of a building, but the present invention can also be applied to detached houses, hotels, offices, and other buildings.

1 Air intake, 2, 2A Resistance device, 10 Building, 11 Ceiling, 12 Room,
21 Cylinder, 22 Cross-shaped resistance plate, 23 Circular resistance plate, 26 Plate portion, 31 Connection portion,
36 plate portion, 38 outermost circumferential slit.

Claims (5)

The system comprises an air supply hole provided in a ceiling, floor, or partition wall of a room for supplying air from the ceiling space side, the underfloor space side, or the wall space side to the room, and a resistance device that provides resistance to the air passing through the air supply hole ;
The resistance device is
a cylindrical body formed with an outer diameter corresponding to the inner diameter of the cylindrical part forming the air supply hole and placed inside the air supply hole, a cross-shaped resistance plate provided on one opening end side of the cylindrical body, and a circular resistance plate provided on the other opening end side of the cylindrical body,
A background noise generating device characterized in that a cross-shaped resistance plate is positioned on the inside of the side of the air intake that is closer to the room, and a circular resistance plate is positioned on the inside of the side of the air intake that is farther from the room . The cross-shaped resistance plate is a cross-shaped plate with slits formed on the inside of the cross-shaped plate whose diameter dimension corresponds to the diameter dimension of the inner peripheral surface of the cylinder, and the slits are formed in the center of each of the four plate parts along the extension direction of each of the four plate parts protruding in all directions from the central plate part of the cross,
2. The background noise generating device according to claim 1, wherein the circular resistance plate is formed based on a circular plate having a diameter dimension corresponding to the diameter dimension of the inner peripheral surface of the cylinder, a circular hole is formed in the center of the circular plate, and four portions spaced 90° from one another on the outer periphery of the circular plate with the center of the circular plate as a reference are left as connecting portions, the outer peripheral edge of the circular plate is removed along the outer periphery to form a circular plate formed on the circular outer peripheral edge, and the four portions spaced 90° from one another with the center of the circular hole as a reference are left as four plate portions continuing from the connecting portions and extending toward the center of the circular hole, an arc-shaped plate portion between adjacent plate portions in the circumferential direction is formed with an arc-shaped slit centered on the center of the circular hole, and an outermost peripheral slit is formed by the space between the circular outer peripheral edge and the inner peripheral surface of the cylinder. 3. The background noise generating device according to claim 2 , wherein the resistor device is configured so that the slit width of the outermost peripheral slit is variable. The resistance device is
The four plate portions of the cross-shaped resistance plate and the four plate portions of the circular resistance plate are arranged to face each other while being shifted in the circumferential direction.
Or,
4. The background noise generating device according to claim 2 or 3 , characterized in that the four plate portions of the cross-shaped resistance plate and the four plate portions of the circular resistance plate are arranged so as to face each other. 4. The background noise generating device according to claim 1 , wherein the resistor device is configured so that the distance between the cross-shaped resistor plate and the circular resistor plate is variable.

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