KR20230137197A - destructive interference soundproof panel - Google Patents

Abstract

The present invention reduces the energy of sound waves by trapping them in the internal space of a soundproofing panel where a soundproofing panel is installed that changes the direction of sound waves flowing into the soundproofing panel to another direction and induces continuous collision and diffraction with the diffraction and soundproofing holes of the reflector. It relates to a destructive interference type soundproofing panel that reduces noise by causing destructive interference with incoming sound waves by causing a change in the phase of sound waves.

Description

Destructive interference soundproof panel

The present invention relates to a soundproofing panel that reduces interfloor noise using destructive interference of sound waves.

In addition, the present invention changes the direction of sound waves, called interfloor noise, caused by vibration caused by impact on the floor or wall to a direction other than the receiving point, and reduces noise through friction and collision with the internal reflector of the soundproof panel. It's about soundproofing panels.

In addition, the present invention changes the direction of sound waves propagating through the air, such as a conversation between people across a wall or partition, or the sound of a telephone ring or television, to a direction other than the receiving point, and reduces noise through friction and collision with the internal reflector of the soundproof panel. It is about soundproofing panels that reduce sound.

Although the standards for low frequencies are different in each country, the present invention divides frequencies below 500Hz into low frequencies and above that into high frequencies . Therefore, from now on, sound waves with a frequency below 500Hz will simply be called ' low frequency ', and sound waves with a frequency above 500Hz will be called ' high frequency '.

Noise caused by low frequencies (simply referred to as 'low frequency noise') exists in natural sounds such as waves on the beach, thunder, and whirlwinds, as well as in subway cars, blowers, ships using diesel engines, buses, trucks, and air conditioners. /Occurs in heating systems, wind turbines, vacuum pumps, transformers, etc. This low-frequency noise causes phenomena such as drowsiness, nervous fatigue, and vomiting, and is known to affect the circulatory system, respiratory system, nervous system, endocrine system, and sleep. Additionally, 70% of interfloor noise, which causes many problems, is low-frequency noise.

Interfloor noise is a type of noise caused by the vibration of reinforced concrete caused by physical impact on the floor or wall, similar to the principle of beating a drum. In other words, interfloor noise is generated by the vibration of the plates when people walk, run, or drop objects. As a result, the vibration of the floor is transmitted not only to the floor, but also to a small amount of inter-floor noise through the walls connected to the floor. In addition, there is also the sound of water flowing through the drain pipe and the noise caused by the rotation of the motor of the refrigerator or washing machine.

And even if it is not upstairs, if it is located with a wall or partition between it and the next door, the sound of the television, phone conversations, and the sound of nails being hammered into the wall will propagate through the wall.

These problems can be caused by increasing the volume and weight of the floor or wall, simply called the slab, or increasing its strength, thereby reducing the amplitude of vibrations caused by impacts or blocking sound waves emitted into the air from passing through the floor or wall. This can be solved to some extent by doing this. However, this solution increases the construction cost of apartments made of reinforced concrete structures and has the problem that it cannot be applied to already built houses.

◆ How to reduce noise

As sound waves pass through materials with different acoustic impedances, a certain amount of absorption , transmission , and reflection occurs as shown in Figure 1.

The acoustic resistance is a unit representing the basic characteristics of a material and is expressed as the product of the density (ρ) constituting the material and the propagation speed (C) of the sound wave, such as “Acoustic resistance (Z) = ρ × C”. Of course, there is a difference in acoustic resistance depending on the temperature of the material, but based on a room temperature of 20℃, the acoustic resistance of air is 0.0004, pure water is 1.48, glass is 12.5, concrete is 8, and iron is 45.4. Each unit is omitted.

Therefore, if a sound wave spreads through the air and hits a concrete wall, the sound wave incident at an angle of θ based on the vertical of the boundary (so-called " normal vector" ) as shown in Figure 1 due to the difference in acoustic resistance between air and concrete. is hardly absorbed or transmitted into the concrete and is mostly reflected back at an angle θ. However, low frequencies penetrate concrete walls to a certain extent. Of course , the amount of sound waves transmitted is inversely proportional to the angle of incidence and the weight that makes up the concrete wall. Therefore, if the concrete wall is made thick to increase weight, it is difficult for even low frequencies to pass through.

Soundproofing panels, such as sound absorbing materials or blocking materials, reduce the energy of sound generated from a noise source or reflect the direction in which the sound travels in a different direction, thereby reducing the noise flowing into a point called the sound collection point. It refers to building materials made for the purpose of blocking airflow.

Sound-absorbing panels using sound-absorbing materials (we will simply call them 'sound-absorbing panels') are characterized by having an internal structure that is porous or has a complex path, so that the incident sound waves collide with the sound-absorbing material as much as possible. This structure is designed to weaken the intensity of noise by dissipating as much of the energy of the sound wave as possible during the process of reflecting or transmitting the sound wave. A representative example of a sound-absorbing panel is an egg carton or pyramid-shaped soundproof wall made of sponge material, which is commonly seen in studios.

As sound waves pass through porous materials, the energy of the sound waves is reduced to a certain amount by friction. And the sound-absorbing material made of polyester uses the threads that make up the fiber like the strings of a string instrument, converting the kinetic energy of sound waves into the vibration energy of the thread, and the vibration energy of the thread is then converted into heat generated by friction with the wind and dissipated. . In other words, conventional sound-absorbing panels were focused on reducing the energy of sound waves.

General sound-absorbing materials, not metamaterials or nanofibers, can mainly absorb noise generated from sound waves in the high-frequency band, but have the problem of allowing sound waves in the low-frequency band below 126Hz to pass through without reducing energy or causing vibration of the material. Of course, even for low frequencies, there is some difference depending on the angle of incidence of the sound wave, and a significant amount of low frequencies incident perpendicularly are transmitted. On the other hand, soundproofing panels made of blocking materials are building materials that utilize the sound reflection mentioned above.

When sound waves pass through a hole or hit a corner, they are diffracted . In general, high frequency waves have strong propagation and weak diffraction. On the other hand, low frequencies have stronger diffraction than linearity. Diffraction is affected by the size of the gap in the soundproofing panel, the structure of the soundproofing panel, and the wavelength of the sound wave. The longer the wavelength of sound is compared to the size of the gap, the more diffraction occurs. In other words, assuming that the wavelength of the sound is constant, the smaller the gap, the more likely diffraction occurs, and as sound waves traveling straight through the narrow gap change into a noise source (or point sound source) in the shape of a semicircle and spread out. At this time , the diffraction angle (θ) generated in the process of passing through the gap is proportional to the wavelength (L) of the sound wave and inversely proportional to the size of the gap (D), as shown below.

And whenever the distance from the point sound source doubles, the sound pressure level is attenuated by 6dB (= 20 x log2), which is called the inverse square law.

◆ Constructive interference and destructive interference

Constructive interference is interference that occurs when two waves with the same phase overlap. In other words, constructive interference indicates that sound waves of the same frequency and wavelength combine with each other and meet crests and crests or troughs and the amplitude of the composite wave increases. Here, phase (位相) refers to the first starting point in one cycle of a repeating waveform. It refers to an angle or a position at a certain moment.

Destructive interference refers to interference that occurs when two waves with opposite phases overlap. In particular, it is also called destructive interference, a phenomenon in which the amplitude of the composite wave becomes 0 when crests and troughs meet. In other words, when the phases of two waves with the same amplitude and frequency are shifted by 180°, the waves are completely canceled out at the moment when the crest and trough overlap.

General low frequencies have a long wavelength and a low number of vibrations, so it is easy to create sound waves that are relatively 180° out of phase with the original sound (hereinafter referred to as ' offset waves '). On the other hand, high frequencies whose duration is not constant have a short wavelength, making it difficult to generate offset waves with different phase differences.

The present invention uses the internal space of the soundproofing panel as a resonance tube (or a tube with one space closed and the other space open as a host resonance device). The resonance tube calculates the wavelength of the sound wave by measuring the height at which continuous sound waves generated from the tuning fork are sent through an open passage as shown in Figure 3, and the sound waves hit the closed surface below and are canceled out or reinforced by the returning sound waves.

The formulas for the constructive interference and destructive interference of the resonant tube and the speed of sound waves are as follows.

● The formula for destructive interference is △r = (n/2)×λ.

● The formula for constructive interference is △r = n × λ.

● The speed of sound waves is v = λ×f.

Here, n refers to a positive number such as 1, 2, or 3. is the frequency of f. λ refers to the wavelength of the sound wave. And △r represents the distance between open space and closed space.

If the wavelength and the height of the resonance tube are (△r = n In other words, if sound waves with the same frequency and wavelength collide with each other by causing a phase change of 180°, just as vehicles running facing each other collide head-on, the sound waves are naturally extinguished.

For example, if it is assumed that the speed of a sound wave with a frequency of 100Hz is 340 m/sec, the wavelength is 3.4 m/cycle and the period is 1/100 second. In other words, the wavelength of a 100 Hz sound wave is 3.4 m, so if a resonance tube with a height of 1.7 m is used, the low frequency of 100 Hz will cause destructive interference due to a canceling wave. However, if a 3.4 m high resonant tube is used, constructive interference occurs. Ironically, sound waves such as 50Hz or 500Hz cause destructive interference at a height of 3.4 m.

In conclusion, it is realistically impossible to create offset waves for all sounds in the audible frequency range. Therefore, as a more realistic way to reduce noise , a Helmholtz resonator is used as shown in Figure 3. If you want to attenuate sound using the principle of the Helmholtz resonator, secure the internal space of the panel (V), the length of the bottleneck (l), and the cross-sectional area of the bottleneck (S) as shown in the following equation in order to match the frequency of the sound wave to be canceled. It must be done.

Here f is the resonant frequency and v is the speed of the sound wave. l represents the length of the bottleneck. S is the cross-sectional area of the bottleneck. V is the volume of the bottle excluding the bottle neck.

The purpose is to provide a soundproof panel that reduces noise caused by physical impact on walls or floors.

The purpose is to provide a soundproof panel that reduces noise dispersed into the air, such as a phone ringtone or conversation heard through a wall.

The purpose is to provide a soundproofing panel that reduces low-frequency noise that conventional soundproofing panels of sound absorbing or blocking materials cannot attenuate.

Acoustically, every object has its own ‘ natural frequency ’. In the case of a general apartment, assuming that the slab 400 of the reinforced concrete structure usually has a thickness of 210 mm, impacts such as children jumping and pounding cause vibration of the slab held by the wall, like hitting a drum. It generates a standing wave with a frequency of approximately 63 Hz. The vibration of the 63 Hz slab creates a standing wave with octave sounds of 126hz, 189hz, and 252hz, which are 2nd to 4th order multiples, and is transmitted to the lower floor.

At the same time, analyzing the apartment structure, the height from the floor to the ceiling of the apartment is 2.3m, the interior height of the ceiling is 0.2m, and the thickness of the slab is 0.21m, so the total height between floors is 2.71m, which means that if the slab shakes due to vibration, Assuming this, constructive interference will occur in sound waves in the 125Hz frequency band. Therefore, even if the sound is small, the layer below feels the tremendous intensity of the sound wave.

The core technologies used in the present invention are as follows.

1. Helmholtz resonator with perforated plate attached

A Helmholtz resonator with a perforated plate has the characteristic that as the number of pores in the perforated plate increases, the value of the sound absorption coefficient at the basic resonance frequency increases, and as the resonance frequency moves to a low frequency band, the width of the sound absorption band gradually expands. According to the present invention, even if the same volume (V) is shared based on FIG. 3, the resonance frequency (f) can be made different by varying the cross-sectional area (S) of the bottleneck, the length (L) of the bottleneck, and the angle of incidence of the sound wave flowing into the bottleneck. This allows the frequency band to be expanded.

In general, the frequency and wavelength of the sound waves that cause interfloor noise occur when people walk or run, so two as necessary to match the frequency and wavelength similar to 125Hz (the frequency band of constructive interference at the floor height of an apartment). Attach the above soundproofing panels to maximize empty space or form a partition to change the internal volume (V) of the soundproofing panel or the length of the bottleneck (l) and adjust the cross-sectional area (S) of the inlet through which sound waves enter. This eliminates inter-floor noise.

2. Change the direction of sound waves to another direction.

In the present invention, the Helmholtz resonator or resonance tube is mainly used to capture sound waves below 200Hz. In addition, for sound waves that are not canceled, the most basic property of sound waves is that " the angle of incidence and the angle of reflection are the same based on the normal vector. " For all sound waves incident at any angle, the direction of travel of the sound wave is determined not at the point of collection but at the wall of the building ( or change to the direction where the blocking surface is located. The ceiling of the apartment is made of a lightweight ceiling steel structure as shown in Figure 2. In this structure, there is an open space for the purpose of installing lights on the ceiling, installing ventilation holes to discharge fine dust and smoke generated when cooking food, or installing drain pipes for water used in the bathroom. .

Therefore, the sound waves propagating down the floor through the vibration of the slab 400 on the upper floor are ① a sound wave that penetrates both the direction plate 201 and the reflector 202 of the soundproofing panel, and ② the sound wave passing through the direction plate 201 of the soundproofing panel. The sound waves that hit and reflect back, and ③ the direction of sound waves that enter the inside of the soundproof panel, are divided into three directions, such as the sound waves moving toward the wall. And ① the reflected sound wave moves upward again and collides with the slab 400, combining with the sound wave reflected again and the sound wave generated by the vibration of the slab to move toward the soundproof panel. Therefore, concave and convex irregularities are installed so that the sound waves reflected by the soundproof panel are diffusely reflected, thereby dissipating the energy of the sound waves.

3. Confines sound waves in space and reduces the energy of sound waves.

In order to confine noise to the internal space of the soundproofing panel, sound waves are blocked from going out, except for the entrance and exit where sound waves enter and exit, as shown in Figures 9 and 12. Also, since noise can escape again through the outlet where the noise exits, the cross-sectional area of the outlet where the noise exits is made smaller than the cross-sectional area of the inlet where the noise flows in. And the sound waves flowing into the soundproofing panel are naturally extinguished by reducing their energy through as many collisions and diffraction as possible inside the soundproofing panel.

Additionally, noise generated across walls can be resolved by attaching the soundproofing panel to the wall so that the direction plate faces the room rather than the wall.

The present invention creates a comfortable environment for people to live in by reducing inter-floor noise, which is difficult to reduce with conventional soundproofing panels.

Additionally, the present invention improves the working environment by reducing noise in places where there is a lot of conversation, such as a conference room.

Figure 1 shows the phenomenon that occurs when a sound wave hits a boundary
Figure 2 is an apartment ceiling structure
Figure 3 shows a Helmholtz resonator and a column resonance tube.
Figure 4 is a perspective view of the soundproof panel
Figure 5 is a perspective view of a soundproofing panel with a partition wall.
Figure 6 is a perspective view of a soundproofing panel in which the directions of the two echo plate exits are bent at 90 degrees.
Figure 7 is a right side view of the soundproofing panel with the directions of the two echo plate exits bent at 90 degrees.
Figure 8 is the back of the direction plate
Figure 9 shows the sound control hole and perforated hole on the back of the direction plate.
Figure 10 shows the sound control opening on the back of the direction plate viewed from the bottom up.
Figure 11 shows the inclination angle of the sound control sphere.
Figure 12 is a size comparison diagram of the inlet and outlet of the sound control port.

The advantages and features of the present invention and methods for achieving them have been described in detail with the accompanying drawings. However, the present invention is not limited to the embodiments and may be embodied in other forms.

Additionally, the terms used in this application are only used to describe specific embodiments and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as "comprise" are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to include one or more other features, numbers, or steps. , it should be understood that it does not exclude in advance the possibility of the existence or addition of operations, components, parts, or combinations thereof.

① Internal volume of the resonator or resonance tube: Figure 4 is a perspective view of a destructive interference type soundproofing panel 100 (hereinafter simply referred to as 'soundproofing panel') made of a direction plate 201 and a reflector 202. The direction plate 201 and the reflector 202 are spaced at a certain interval in consideration of the empty space (hereinafter referred to as ' common hole 206') as shown in FIG. 4 and are connected using a connecting member 207 to form a soundproof panel. Produce (100). The connecting member 207 is only for convenience of explanation. Even if the connecting member is not used, brackets or adhesives are used when attaching the direction plate 201 and the reflector 202 to the ceiling or wall as shown in FIG. 2. So you can secure a separate empty space.

And when two or more soundproofing panels are connected to form one soundproofing panel, a gap is created between the direction plate and the direction plate and between the reflector and the reflector, so that the direction plate (as shown in Figure 5) prevents noise from entering or exiting. H-shaped noise packing 106 made of silicon or rubber is attached along the peripheral surfaces of 201) and the reflector 202, respectively. If a gap occurs, the absorption function of the Helmholtz resonator decreases and sound waves leak out to the outside, creating another noise source.

Conversely, if the internal space of the soundproofing panel is large, the entire space of the common opening 206 is artificially separated vertically, horizontally, or diagonally using a partition wall 208 as shown in Figures 5 to 9 to form a separate soundproofing panel. There is also a way to control the internal volume of .

② Changing the direction of sound waves: In addition to forming a common sphere together with the reflector 202, the direction plate 201 performs the function of changing the direction of sound waves.

The sound control sphere 210 installed on the back of the direction plate plays the role of changing the direction of sound waves. 4 and 9, the front of the direction plate 103 is made of a flat perforated plate, and the perforated hole is connected to the inlet 211 of the sound control port 210 on the back. As shown in FIG. 11, the sound control port 210 has a direction ( A reflective plate such as a three-dimensional hemispherical dome or a geodesic dome or a triangular plate as shown in Figure 9 that forms an inclination angle with the inlet in order to change the direction (e.g. vertical direction) to another direction (e.g. horizontal direction) It has a shape and is composed of an outlet (which becomes the outlet 212 that emits sound waves) that is open in a vertical or horizontal direction.

In Figure 10 or Figure 11 or Figure 12, the direction of the exit 212 is downward, which is an example of a soundproofing panel standing vertically like a partition. When used as a ceiling material, if necessary, the direction of the outlet 212 may be horizontal or diagonal. You can. The inlet 211 and the outlet 212 of the sound control sphere 210 serve as the bottleneck of the Helmholtz resonator, and the cavity becomes the volume of the Helmholtz resonator or resonance tube.

As shown in Figure 11, the normal vector perpendicular to the individual inner surface of the hemispherical dome, geodesic dome, or triangular plate of the sound control sphere (hereinafter referred to as the ' inner surface of the sound control sphere ') is not the inlet 211, but the outlet ( 212) or at least the boundary line between the inlet 211 and the outlet 212. Since the incident angle and reflection angle of the sound wave are the same based on the normal vector, all sound waves incident on the inlet are directed toward the outlet. In addition, since the sound control hole forms an inclined angle with the entrance, most sound waves incident on the inclined surface are reflected rather than transmitted. An inclined surface is structurally thicker than a vertical surface, and creates a smaller refraction angle when transmitted.

Depending on the frequency, some of the sound waves are refracted or transmitted, and some sound waves are diffracted when they hit the corners or corners of the inlet 211 or the outlet 212 of the sound control hole 210, leading to an undesirable direction (for example, the sound receiving point). ), but movement to the outside is blocked by the reflector 202 or the partition wall 208.

If the soundproofing panel is located on the ceiling to prevent inter-floor noise, the sound waves generated by the slab 400 are incident perpendicularly (or Z-axis) on the front of the direction plate 201 as shown in Figure 4, so the soundproofing device The soundproofing panel 100 is installed by attaching it to the wall so that the exit 212 of (210) faces the right (or X-axis or Y-axis) wall. However, if the soundproofing panel cannot be vertically attached directly to the ceiling or wall due to obstacles such as fluorescent lights, air conditioners, or sprinklers, the blocking surface 204 is installed as a soundproofing panel as shown in Figure 4 to artificially block the movement of sound waves. It can be used by attaching it to (100). Also, you must block it with silicone, etc. to prevent any gaps between the soundproofing panel and the fluorescent lights or sprinklers.

The soundproofing panel 100 is an additional direction plate having an outlet direction of the soundproofing device having a Y-axis direction rotated by ±90 degrees from the outlet direction in addition to the direction plate of the soundproofing device facing the X axis as shown in FIGS. 6 and 7. A soundproofing panel having a double-structured direction plate can be manufactured by inserting a direction plate facing the X-axis and the reflector plate. And, if necessary, the soundproofing panel can be manufactured with 4 or 8 layers of the above-mentioned direction plates. If a plurality of direction plates are attached, the direction of the exit 212 of the sound suppression port 210 of each direction plate 201 is within 90 degrees counterclockwise or clockwise based on the exit direction of the sound suppression port 210 of the highest direction plate. They are manufactured in each direction rotated at 45 degrees. For example, if a direction plate with a quadruple structure is installed inside the soundproofing panel, the direction of the first outlet is set to the Plates can be produced. In this case, each direction plate 201 installed inside serves as a reflector along with the function of the unevenness 205 of the direction plate to change the direction of travel of the scattered sound waves.

In addition, if you want to install a soundproofing panel in a room where high frequency generation is low, there is no need for all soundproofing devices to change the direction of sound waves. A sound control sphere that does not change the direction of sound waves has the inlet and outlet directions connected in a straight line, like the bottleneck of a Helmholtz resonator, and can also be manufactured as a perforated hole in which the inlet protrudes or is recessed from the cavity sphere.

③ Resonance frequency : In the drawing, the entrance 211 through which sound waves flow is implemented as a circle, but triangles, squares or polygons are also suitable. Also, when designing the direction plate, the equivalent length of the bottleneck presented by the Helmholtz resonator can be increased or decreased by increasing or decreasing the length (hereinafter referred to as ' length of the sound control port') from the inlet 211 to the outlet 212. . In addition, depending on the angle at which the sound wave enters the inlet, the size of the inlet's cross-sectional area is calculated differently even if the inlet 211 has the same cross-sectional area. For example, even if it is a circular inlet, if the scattered sound waves are incident on the inlet at an angle of 45 degrees, the circular inlet is formed into an oval shape, and the length of the sound control sphere is also calculated differently.

In the drawing, the inlet 211 of the perforated sound control port 210 is enlarged, but this is an example to aid understanding. The actual diameter of the inlet 211 is small, 0.1 to 50 mm, and the opening rate (or perforation rate) of the inlet is small. Rate) may vary depending on the durability and design of the soundproofing panel or the calculation of the absorption rate and reflectance of sound waves.

Figure 10 shows the shape of the sound control device 210 when viewed from below. The sound control devices may be arranged regularly when the length of the sound control devices is the same, or irregularly when the lengths of the sound control devices are different, as shown in FIG. 10 or FIG. 8 .

As shown in Figure 11, the sound waves that hit the inner surface 221 of the sound control device move along the rear boundary surface of the direction plate 201 in the direction of the open outlet 212, and some of the sound waves hit the outer surface 222 of another sound control device. collide. However, the outer surface 222 of the sound control sphere 210 is shaped like a hemispherical dome as shown in FIG. 12 or like the outside of a triangular plate as shown in FIG. 9, so some reflection and scattering of the impacting sound waves occurs, but most of the sound waves travel in the same direction. moves towards. As a result, the sound wave returns in the direction it came from after colliding with the wall.

At this time, the sound waves moving inside the soundproofing panel pass through the exit of the soundproofing port 210 and then go back to the front of the soundproofing panel and cancel out the incident sound waves, but some sound waves may cause reverberation due to constructive interference. Therefore, if you want to reduce the reverberation inside the ceiling, it is better to make the cross-sectional area of the outlet 212 smaller than the cross-sectional area of the inlet 211. Also, as mentioned in the resonance tube mentioned earlier, if the distance to the wall (or blocking surface) is too small, a canceling wave cannot be created, so it prevents the movement of the sound wave so that it is at least half the size of the wavelength of the sound wave to be controlled. The length from the wall (or blocking surface) to the center point of the first entrance of the sound control device must be adjusted to be half the wavelength of the sound wave to be canceled (for example, 34 cm for a sound wave with a frequency of 500 Hz).

If the area of the wall or ceiling is large and the soundproofing panels 100 need to be connected and attached, the common openings 206 inside the soundproofing panels, as shown in Figures 4 and 5, are connected to the joints 206 of the soundproofing panels attached without using a blocking surface. ) can be connected to each other. If the cavities are connected to each other, the total volume of the empty space increases, creating an environment in which it is easy to create a resonance frequency for low frequencies.

In conclusion, the present invention, as mentioned above, even if the cross-sectional area of the inlet and the cross-sectional area of the outlet are the same, the size of the cross-sectional area of the inlet is varied according to the angle of the incident sound wave or of the individual sound control port, and at the same time, the cross-sectional area of the outlet is varied. By making it relatively smaller than the size of the cross-sectional area of the inlet, the width of the resonance frequency can be widened. However, if the cross-sectional area of the inlet and the outlet cannot be adjusted, another method is to make the length of the sound control sphere straight without any bends, or, as mentioned earlier, make some sound control spheres into a hemispherical dome shape to change the direction of the sound wave. By changing the equivalent length and connecting two or more soundproofing panels to increase the volume of the cavity 206 or by separating the cavity 206 using the partition wall 208, the bandwidth of the resonance frequency is expanded. Or it can be reduced.

④ Energy consumption of sound waves : The reflector 202 is a square erected at a 45 angle like ◀ as shown in FIG. 5, or a diffraction sphere (回折具) (203) can be made to be arranged regularly or irregularly. The diffraction sphere 203 serves to dissipate the energy of the sound waves by causing friction and collision with the sound waves moving inside the soundproofing panel. Since the diffraction sphere requires friction and diffraction of sound waves, it does not require a separate design or shape.

The reflector 202 performs the following functions. The direction of sound waves introduced below is just an example.

1. It serves to block sound waves flowing into the cavity 206 from going out to the receiving point.

2. The sound waves flowing into the cavity 206 collide with the soundproofing sphere 210 and the diffraction sphere 203 while moving in the vertical or horizontal direction, causing friction and diffraction.

3. Among the sound waves that hit the blocking surface 204 or the wall and are reflected back, some sound waves go out to the front of the soundproofing panel through the sound wave inflow outlet of the soundproofing hole.

Convex, concave, or square-shaped irregularities 205 are attached to the direction plate 201 as shown in FIG. 5 to generate scattering to reduce the energy of sound waves that do not enter the soundproofing hole 210 and are reflected.

100: Soundproof panel 106: Noise packing
201: direction plate 202: reflector 203: diffraction sphere
204: Blocking surface 205: Irregularity 206: Utility port
207: Connecting member 208: Bulkhead 209: Bulkhead hole
210: Sound control port 211: Entrance of sound control port 212: Exit of sound control port
221: inner surface of sound control mouth 222: outer surface of sound control mouth
400: slab 410: wall

Claims (8)

Equipped with a plurality of soundproofing spheres that have an inlet through which sound waves enter and form a hemispherical dome or a geodesic dome or a triangular plate forming an inclination angle with the inlet to change the direction of travel of the sound waves to one side of the outlet where the sound waves exit. direction board;
a reflector that blocks the sound waves from reaching the receiving point; and
a cavity in which the direction plate and the reflector are spaced apart at regular intervals to allow movement of the sound waves;
A destructive interference type soundproofing panel comprising a. According to paragraph 1,
A destructive interference type soundproofing panel, wherein a normal vector perpendicular to the individual inner surfaces of the hemispherical dome, the geodesic dome, or the triangular plate is directed toward an interface between the inlet and the outlet or is fixed toward the outlet. According to paragraph 1,
H-shaped noise packing that is attached to the boundary surface of the direction plate and the reflector to block the sound waves from going out;
An offset interference type soundproofing panel, characterized in that it additionally includes. According to paragraph 1,
A partition separating the space of the cavity to block the movement of the sound waves;
An offset interference type soundproofing panel, characterized in that it additionally includes. According to paragraph 1,
A destructive interference type sound insulation board, characterized in that the length of the center point of the entrance, which is spaced apart from the blocking surface or wall that prevents the movement of the sound waves, is half the wavelength of the sound wave to be canceled. According to paragraph 1,
It is located between the direction plate and the reflector and has the direction of the outlet of the sound suppression device rotated in increments of 90 to 45 degrees counterclockwise or clockwise based on the direction of the outlet of the sound suppression device of the direction plate. A destructive interference type soundproofing panel, characterized in that it is additionally provided with a direction plate. According to paragraph 1,
The reflector includes a diffraction sphere that induces friction and diffraction with the sound waves;
An offset interference type soundproofing panel, characterized in that it additionally includes. According to paragraph 1,
A destructive interference type soundproofing panel, characterized in that it has at least one soundproofing port whose length between the inlet and the outlet is different, or where the size of the cross-sectional area of the inlet and the cross-sectional area of the outlet are different.