APPARATUS FOR REDUCING NOISE

TECHNICAL FIELD

The present invention relates to an apparatus for reducing noise, and more particularly, to an apparatus for reducing noise which is mounted on soundproofing walls that are installed at sides of roads.

BACKGROUND ART

When noise generated from roads is transferred to adjacent buildings such as apartments, it creates a lot of inconvenience for people living in the apartment. In order to solve the noise problem, soundproofing walls are generally installed on boundaries of the roads. Soundproofing walls include pillars arranged on the road with a constant interval therebetween, and soundproofing panels that are coupled between the pillars. In addition, in the soundproofing panels, a sound absorbing material may be disposed.

However, conventional soundproofing walls can block noise transferred to low floors of the apartment to some degree, however, cannot block the noise transferred to the high floors sufficiently. In order to block the noise transferred to the high floors, a height of the soundproofing wall can be increased, however, there is a limitation in increasing the height of the soundproofing wall in views of wind load, landscape rights of apartments adjacent to the soundproofing walls, and installation costs.

FIG. 1 shows a noise reducing apparatus 10 according to Korean Registered

Utility Model No. 378864. In the noise reducing apparatus 10, pillars 2 having H- shaped cross-sections are arranged on a base 1 with a predetermined interval, and soundproofing panels 3 are stacked between two pillars 2 to form a soundproofing wall

5. Conventionally, a distance (L) between the two pillars ranges from 1 m to 10m.

The noise reducing apparatus 10 mounted on the soundproofing wall 5 using a bracket 4 is formed by engaging a plurality of sound reducing units 11. The sound reducing units 11 are engaged with each other using a protrusion (not shown) formed on a side of the noise reducing unit 11 and a recess 15 formed on the other side of the noise reducing unit 11.

The noise reducing apparatus 10 mounted on one soundproofing wall 5 (a unit of soundproofing wall formed by stacking the soundproofing panels 3 between the two pillars 2) is formed by engaging a plurality of noise reducing units 11 as shown in FIG. 1

because of a fabrication method of the noise reducing unit 11.

The noise reducing unit 11 is fabricated by an injection molding method, and in the injection molding method, if the length of a product (noise reducing unit) is 50 cm or longer, it may cost tens of million Korean Won to fabricate a mold for performing the injection molding process. Therefore, the length (T) of the noise reducing unit 11 fabricated by the injection molding is limited up to 50 cm to reduce the fabrication costs. However, in the noise reducing apparatus 10, a lot of (tens ~ hundreds of) protrusions and recesses 15 must be engaged in order to install ten to twenty noise reducing units 11 in one noise reducing wall 5, and thus, much time and labor are consumed in mounting the noise reducing apparatus 10 on the soundproofing wall 5.

As shown in FIG. 2, noise generated from the road (N1 and N2 denote proceeding directions of acoustic waves of the noise) proceeds upward to the noise reducing apparatus 10. Some of the noise (N1 ) transmits a hole 12a formed on a side portion 12 of the noise reducing unit and is absorbed by a sound-absorbing material 13 disposed in the side portion 12. However, the noise proceeding over the side portion 12 can be transferred to the apartment, or is reflected by an inner wall 14.

Since the noise is an acoustic wave, a small amount of the noise energy can be reduced by the inner wall 14 due to diffraction. However, the proceeding direction of the noise and an extension of an inner space 14a that is defined inner walls 14 make a nearly right angle, and thus, it is difficult to generate destructive interference of the noise sufficiently. Therefore, it is difficult to obtain a noticeable noise reducing effect by the destructive interference of noise.

During the examination process of Korean Patent Application No. 2005-111195 that is related to the present invention, Japanese Patent No. 3616623 and Korean Registered Utility Model No. 380489 were provided as cited references for reputing the inventive step of the invention of Korean Patent Application No. 2005-111195. However, the corresponding Korean application was granted by the amending of its claims, and the present invention is refined from the invention of the above Korean Patent Application No. 2005-111195.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a soundproofing wall and a noise reducing apparatus mounted on the soundproofing wall according to the conventional art;

FIG. 2 is a cross-sectional view of the noise reducing apparatus taken along line

N-Il of FIG. 1 ;

FIG. 3 is an exploded perspective view of a noise reducing apparatus according to an embodiment of the present invention;

FIG. 4 is a cross-sectional view of the noise reducing apparatus that is in the assembled status taken along line IV-IV of FIG. 3;

FIG. 5 is a front view illustrating a process of fabricating a spiral member in the noise reducing apparatus according to the embodiment of the present invention;

FIG. 6 is a front view illustrating a modified example of the process shown in FIG. 5; FIG. 7 is a front view illustrating another modified example of the process shown in FIG. 5;

FIG. 8 is a front view illustrating another modified example of the process shown in FIG. 5; and

FIG. 9 is a diagram showing examples of various spirals.

DETAILED DESCRIPTION OF THE INVENTION

TECHNICAL PROBLEM

The present invention provides a noise reducing apparatus having an improved noise reducing effect. The present invention also provides a noise reducing apparatus that can be easily assembled and mounted on a soundproofing wall so that costs and time taken for mounting the noise reducing apparatus can be reduced.

TECHNICAL SOLUTION According to an aspect of the present invention, there is provided an apparatus for reducing noise comprising: a spiral member including a plate-shaped spiral portion having a spiral cross-section; two side shielding members for shielding opened lateral sides of the spiral member; and a central member disposed in the spiral member and holding the two side shielding members tight to the spiral member. Preferably, the spiral member includes a sound absorbing material attached onto an inner surface of the spiral member.

Preferably, an inner end portion of the spiral member is fixed on the central member.

Preferably, the side shielding members include penetration holes, the central

member is disposed to penetrate through the penetration holes, screws are formed on both end portions of the central member, and the side shielding members are attached to the opened lateral sides of the spiral member by coupling nuts screwed to the end portions of the central member. Preferably, apparatus for reducing noise further comprises a common member commonly disposed in two or more spiral members. The common member may be a cable, both end portions of which are fixed directly or indirectly to the ground, or a member having a large rigidity.

Preferably, the spiral member further includes a flat portion extending from an outer end portion of the spiral member and having a substantially flat shape. The flat portion may include a sound absorbing material attached onto an inner surface of the flat portion.

Preferably, an opening having a width that ranges 50% to 200% of a width of the flat portion is formed between an outer end portion of the flat portion and an outer surface of the spiral portion.

Preferably, apparatus for reducing noise further comprises a front filtering member preventing dirts, large insects and animals from coming into the spiral portion but allowing noise to be induced into the spiral portion.

Preferably, a bracket is coupled to a lower portion of the spiral portion for fixing the noise reducing apparatus to a soundproofing wall.

ADVANTAGEOUS EFFECTS

A noise reducing apparatus having an improved noise reducing effect is provided. A noise reducing apparatus that can be easily assembled and mounted so that costs and time taken for mounting the noise reducing apparatus can be reduced is provided.

A noise reducing apparatus that is more hygienic because dirts, large insects or animals such as birds are not allowed into the apparatus is provided. A noise reducing apparatus that does not fall down even when it is subject to strong winds is provided.

BEST MODE

MODE OF THE INVENTION

Hereinafter, a noise reducing apparatus according to an embodiment of the present invention will be described with reference to FIGS. 3 through 9. The noise reducing apparatus 100 of the current embodiment includes a spiral member 110 including a spiral plate 111 having a spiral cross-section, two side shielding members 140 shielding both opened lateral sides of the spiral member 110, and a central member 150 disposed in the spiral member 110 to attach the two side shielding members 140 to the spiral member 110. The spiral member 110 can further include a flat portion 112 if necessary, and the noise reducing apparatus 100 can further include a front filtering member 130, a sound-absorbing material 120, and a common member 170. Hereinafter, the noise reducing apparatus including the above elements will be described as follows.

The spiral portion 111 in the spiral member 110 of the noise reducing apparatus 100 is a plate-shaped member having a spiral cross section. The spiral may be an

Archimedes spiral (a), a logarithmic spiral (or an equiangular spiral) (b), a hyperbolic spiral (or reciprocal spiral) (c), or a lituus spiral (d) (from Encyclopedia Britannica, Inc.) shown in FIG. 9. The spiral portion 111 of the current embodiment 111 has a similar shape to that obtained by cutting a part of the lituus spiral (d), however, the cross- section of the spiral portion 111 is not limited thereto, and any spiral, a part of any spiral, and a modified shape of any spiral can be selected as the spiral portion 111. In addition, a structure formed as a spiral by connecting flat panels or curved panels can be a kind of the spiral member 110.

The flat portion 112 extends from an outer end portion 111b of the spiral portion 111 and has a flat shape, and the outer end portion 111 b of the spiral portion 111 is an end portion of the spiral portion, which is adjacent to a point C. The point C that is a boundary between the spiral portion 111 and the flat portion 112 is a point where a radius of curvature is rapidly changed to be nearly infinite, when the radius of curvature is measured along the cross-section of the spiral portion 111 from an inner end portion 111a of the spiral portion 111. In addition, the flat portion 112 is not limited to a complete flat shape (as in the current embodiment), however, if the flat portion is less curved than the spiral portion 111 , it can be referred to as the flat portion.

The flat portion 112 increases an area of an opening 113 that will be described later so as to induce the noise into the spiral portion 111 as much as possible. The flat

portion 112 can be separately fabricated with the spiral portion 111 , however, it may be integrally fabricated with the spiral portion 111 as in the current embodiment for reducing the costs.

Referring to FIG. 5, the spiral member 110 is fabricated using a metal plate using an aluminum plate or a zinc plated steel plate. When a metal plate having a constant width and length is used, the sound absorbing material 120 may be attached onto an inner surface of the metal plate in advance, and then, a portion of the spiral portion that will be the inner end portion 111a is forcedly inserted into a recess of a rotary shaft 190. The recess is formed along the length of the rotary shaft 190. After that, the metal plate is placed on a plane P, and the rotary shaft 190 is rotated in a direction A shown in FIG. 5, then, the metal plate is wound on the rotary shaft 190. After rotating the metal plate by a required number of rotations, the rotating force applied to the rotary shaft is removed, and then, the metal plate wound on the rotary shaft is unwound to some degree due to elastic restoring force to form the shape of FIG. 4. Then, the metal plate is removed from the rotary shaft 190, and then, the spiral member 110 can be obtained. The spiral member 110 having the desired cross-section can be obtained by controlling the material used to form the metal plate, a thickness of the metal plate, and winding number.

The spiral member 110 of FIG. 4 can be fabricated using an extrusion molding method, and in this case, the spiral member 110 may be formed of a synthetic resin for reducing the fabrication costs.

If the spiral member 110 is fabricated using any one of the metal plate and the extrusion molding, one spiral member 110 can be fabricated to have a length of a few meters (length in a direction of Y and -Y). Therefore, only one noise reducing apparatus 100 can be disposed between two pillars 2, and thus, the noise reducing apparatus 100 can be mounted on the soundproofing wall much easier than the conventional noise reducing apparatus 10 that is formed by assembling ten to twenty noise reducing units 11 on the soundproofing wall.

Meanwhile, since the spiral member has the spiral cross-section, noise N4 and N5 induced through the opening 113 comes into the inner space of the spiral member 10, and the noise undergoes destructive interference with each other to extinguish a lot of the noise. In particular, the noise reducing apparatus 100 of the current embodiment is different from the conventional art shown in FIGS. 1 and 2 in that the noise N4 and N5 are induced into the spiral member 110. In addition, unlike the

invention of Japanese Patent No. 3616623, the central member 150 is disposed in the inner portion (a portion from the inner end portion 111a to a point 360° rotated along the spiral member) of the spiral member 110, and thus, the noise can be reflected more, and the reduction amount of the noise can be increased. In order to reduce the noise induced into the spiral member 110 as much as possible, the sound absorbing material 120 may be attached onto an inner surface 111c of the spiral portion 111 and an inner surface 112c of the flat portion 112. In this case, some of the noise N3, N4, and N5 is absorbed by the sound absorbing material 120, and the rest of the noise can be extinguished by the destructive interference due to the spiral member 110. The sound absorbing material can be a porous member formed of a synthetic resin such as polyester, however, it is not limited thereto and any kind of member having the noise reducing effect can be used as the sound absorbing material. When the noise reducing apparatus of the current embodiment is compared to the conventional noise reducing apparatus including the sound absorbing material, an area (inner surface of the spiral member 110) to which the sound absorbing material is attached is larger than that of the conventional art, and thus, the sound absorbing effect can be greater than that of the conventional art.

The opening 113 shown in FIG. 3 is an entrance through which the noise is induced into the spiral member 110. The opening 113 of the current embodiment is defined by an outer end portion 112a of the flat portion 112 and the outer surface 111d of the spiral portion 111 , which is adjacent to the outer end portion 112a. If there is no flat portion, the opening 113 can be defined by the outer end portion 111b of the spiral portion and the outer surface 111d that is adjacent to the outer end portion 111 b.

Preferably, a width W2 of the opening 113 ranges from about 50% to 200% of a width W1 of the flat portion 112 (W1 is defined as a length from the point C to the outer end portion 112a of the flat portion 112, however, if the above length is 20cm or shorter or there is no flat portion, the width W1 is set as 20cm). If the width W2 is shorter than 50% of the width W1 , the amount of noise induced into the spiral member 110 is reduced and the noise reducing effect is weakened. If the width W2 is longer than 200% of the width W1 , the wind load applied to the noise reducing apparatus 100 is greatly increased and the structural stability of the noise reducing apparatus 100 is weakened.

The front filtering member 130 may be disposed on a position adjacent to the opening 113. The front filtering member 130 blocks dirts, large insects and animals

from coming into the spiral member 110. Since the noise generated from the road can be reflected to the road by the front filtering member 130, the front filtering member 130 has as many and large openings as possible. When a ratio of openings 130a in an entire area (except for a lower end portion 131 and an upper end portion 132 for coupling to the spiral member) of the front filtering member 130 to the entire area is defined as an opening ratio, the opening ratio ranges from 10% to 99.99%.

As shown in FIG. 4, the front filtering member 130 is coupled to the spiral member 110 using bolts and nuts, however, the front filtering member 130 can be coupled to the spiral member 110 using other means such as a rivet and a welding process.

In the current embodiment, the front filtering member 130 is formed from a plate, however, it is not limited thereto. That is, the front filtering member may be formed from bars, rods, wires, or a mesh.

The noise reducing apparatus 100 may further include side shielding members 140 for shielding opened lateral sides (end portions in the direction of Y and -Y) of the spiral member 110. The side shielding member 140 of the current embodiment includes a bent portion 141 on a boundary thereof, and thus, the bent portion 141 surrounds the boundary portions of the spiral member 110 and the front filtering member 130 so that the side shielding member 140 does not rotate about the Y axis. The side shielding member 140 prevents dirts, large insects and animals from coming into the spiral member 110 like the front filtering member 130, and restrains vibrations of the spiral member 110 caused by the noise by holding the spiral member 110 tight so as to maximize the noise reducing effect of the spiral member 110.

The side shielding member 140 can be fixed on the spiral member 110 and/or the front filtering member 130 using a welding process, a rivet, or a screw, and in the current embodiment, the two side shielding members 140 disposed on both opened lateral sides of the spiral member 110 are fixed to each other using a central member 150. That is, the side shielding member 140 includes a penetration hole 140a, and the central member 150 penetrates the penetrations holes 140a and is disposed in the spiral member, and after that, nuts 160 are coupled to screws formed on both end portions 151 of the central member 150. Therefore, the two side shielding members 140 held tight to the spiral member 110.

The central member 150 can be formed as a rod with a no inner space or a pipe with a hollow inner portion, and in particular, if the central member 150 is formed as a

pipe like in the current embodiment, the following advantages can be obtained.

Although the noise reducing apparatus is fixed on the soundproofing wall 5 using brackets 180 that will be described later, the noise reducing apparatus 100 might fall off the soundproofing wall 5 in a case where the wind load in the transverse direction is abnormally strong. When the noise reducing apparatus 100 is separated from the soundproofing wall 5 and falls down to vehicles on the road or people walking on adjacent sidewalk, a fatal accident may occur.

Such an accident caused by the separation of the noise reducing apparatus 100 from the soundproofing wall 5 can be prevented by inserting a common member 170 in the central member 150 having the pipe shape. That is, when the common member 170 is disposed commonly in a series of noise reducing apparatuses 100 disposed in the direction of Y and -Y, even if one of the noise reducing apparatuses 100 is separated, the noise reducing apparatus 100 does not fall down due to the common member 170. Therefore, the accident caused by the falling of the noise reducing apparatus 100 can be prevented.

As shown in FIG. 3, when a cable is used as the common member 170, both ends of the cable must be fixed on the ground or on members that are firmly fixed on the ground, for example, the pillars 2 of the soundproofing wall 5. If a member having a large rigidity such as an iron bar is used as the common member 170, the common member 170 can be only inserted into the central member 150 without being fixed on the ground.

Meanwhile, the common member 170 is disposed in the central member 150 according to the current embodiment, however, if there is no central member, the common member 170 can penetrate through the penetration holes 140a formed on the side shielding members 140 to obtain the same effect. That is, the central member 150 is not essential for installing the common member 170, and moreover, the common member 170 can be used when there is no side shielding member.

In the description above, the rotary shaft 190 is separated after completing the spiral member 110, and then, the central member 150 is disposed in the spiral member. However, after forming the spiral member 110, the rotary shaft 190 can be used as the central member 150 without separating the rotary shaft 190. In this case, the rotary shaft 190 may be coupled to another rotary shaft 190 located nearby by coupling means, for example a coupling member which has threaded recesses in both ends. Then, fabrication processes can be reduced, and thus, costs and time taken to fabricate the

apparatus can be reduced. In addition, the inner end portion 111a of the spiral member 110 is fixed on the central member 150, and thus, it can restrain the vibrations of the spiral member 110 and improve the noise reducing effect.

In addition, a pipe-shaped central member 250 (refer to FIG. 6) having slots separated from each other in a length direction and high thickness, and a metal plate having protrusions 111a corresponding to the slots are prepared, and then, the protrusions 111a of the metal plate are forcedly inserted into the slots and the metal plate is rotated to some degree about the central member 250 as shown in FIG. 5. Then, the rotating force is removed, and thus, the spiral member 110 shown in FIG. 4 can be obtained. In this case, the costs and time taken for fabricating the noise reducing apparatus can be reduced. Other features of the central member 250 that are not described are the same as those of the central member 150.

The central member 250 of FIG. 6 uses a pipe having a high thickness, and thus, the end portion 111 a of the metal plate can be inserted toward the center of the central member 250 as shown in FIG. 5 and the insertion state will not change. However, as shown in FIG. 7, in a case where the end portion 111a of the metal plate is bent toward the opposite direction of the rotation direction (A), the end portion 111a does not come out from the central member 350 due to the bent portion, and thus, a standard pipe having a common thickness can be used as the central member 350. Other features of the central member 350 that are not described are the same as those of the central member 250.

In order to substantially prevent the end portion 111a of the metal plate from escaping out of the central member 250, a central member 450 shown in FIG. 8 can be used. The central member 450 includes a protrusion 450a, and when the end portion 111a is coupled to the protrusion 450a using a rivet, a screw, or a welding process, the end portion 111a can be prevented from coming out of the protrusion 450a. Other features of the central member 450 that are not described are the same as those of the central member 250.

The bracket 180 is used to mount the noise reducing apparatus 100 on an upper end portion of the soundproofing wall 5, and in the current embodiment, a divided type bracket 180 is used. When the divided type bracket 180 is used, the noise reducing apparatus 100 can be mounted on the soundproofing wall 5 without taking into account the thickness of the upper end portion of the soundproofing wall 5. An upper portion 181 of the bracket 180 is coupled to the noise reducing apparatus 100 (in more detail,

the lower portion of the spiral portion 111 ) using screws, the welding, or the rivet, and a lower portion 182 of the bracket 180 is coupled to the upper end portion of the soundproofing wall 5 using the screws, the welding process, or the rivet. The noise reducing apparatus 100 of the current embodiment can be mounted to the soundproofing wall using another type of bracket. Otherwise, the noise reducing apparatus 100 can be directly mounted on the soundproofing wall using the welding process or an adhesive without using the bracket 180.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims.