JP4086249B2 - Sound absorber - Google Patents

Description

  The present invention relates to a sound absorbing device for a device that generates heat and sound, and in particular, effectively absorbs harmonic frequency noise generated from a transformer installed in a rental room of an apartment or an electric room of an office building. The present invention relates to a sound absorbing device capable of

  Conventionally, as this kind of sound absorbing device, a device in which a sound absorbing material made of glass wool is pasted on a concrete wall and ceiling of a rental room of an apartment where an electric power device such as a transformer is installed or an electric room of an office building is known. (For example, refer to Patent Document 1).

  However, in such a sound absorbing device made of a porous sound absorbing material such as glass wool, low-order harmonic frequency noise generated from a transformer cannot be effectively absorbed. There is a possibility that harmonic frequency noise propagates in the dwelling units, which has a great influence on the lives of residents.

  For this reason, a method has been devised in which a low-frequency sound-absorbing material previously developed by the present inventors is attached to the concrete wall and ceiling of the electric room.

  According to this low-frequency sound-absorbing material, low-order harmonic frequency noise generated from a transformer or the like can be absorbed efficiently, and the propagation of noise to the dwelling unit can be suppressed, but the existing transformer That is, when a low frequency sound absorbing material is installed in an operating transformer, there is a problem in that the operation of the transformer must be stopped and the low frequency sound absorbing material must be installed during a power failure. That is, when a low frequency sound absorbing material is applied to a concrete wall or ceiling, it is usually necessary to attach a spindle pin for fixing the low frequency sound absorbing material to the concrete wall or ceiling. In addition, it is necessary to stop the operation of the transformer for a long time, and in addition, in conventional sound absorbing devices, it is usually necessary to install low-frequency sound absorbing materials on all the walls and ceiling of the concrete. It took a long time to install the high frequency sound absorbing material, and there was a problem that it was expensive.

Japanese Patent Laying-Open No. 2003-45726 (paragraph “0002”)

  The present invention is installed in an electric room by covering the transformer with a sound absorbing cabinet having an open part in part and installing a low-frequency sound absorbing material on the wall of the electric room at least facing the open part. It is possible to effectively absorb the noise of harmonic frequency generated from the transformer, to suppress the propagation of noise into the dwelling unit, and to use the low frequency sound absorbing material in a short construction period and at low cost. It aims at providing the sound-absorbing device which can be installed.

The first sound absorbing device of an embodiment of the present invention include a device for generating the installed thermal and sound in the electric room and Tsutsumihi the device, and the sound absorbing cabinet one side is open, the electric room of the sound-absorbing cabinet A first low-frequency sound-absorbing material pasted on the wall facing the opening, and the sound-absorbing cabinet has a rigid wall layer having a predetermined mass and a third wall stuck on the device side of the rigid wall layer. A low-frequency sound absorbing material .

Absorbing apparatus according to a second aspect of the present invention, a device for generating the installed thermal and sound in the electric room and Tsutsumihi the device, and the sound absorbing cabinet one side is open, the electric room of the sound-absorbing cabinet A first low frequency sound absorbing material affixed to a wall surface facing the open portion, and a second low frequency sound absorptive material affixed to a ceiling adjacent to the wall surface of the electric room , a rigid wall layer having a mass, a shall and a third low-frequency sound absorbing material that is affixed to the device side of the rigid wall layers.

According to a third aspect of the present invention, in the sound absorbing device according to the first aspect or the second aspect , the open portion is provided at a position farthest from the sound source of the device.

According to a fourth aspect of the present invention, in the sound absorbing device according to any one of the first to third aspects, the open portion is provided on the front side of the device.

According to a fifth aspect of the present invention, in the sound absorbing device according to any one of the first to fourth aspects, the rigid wall layer is a metal plate having a thickness of at least 1.6 mm, or a metal plate. It is comprised with the board | plate material which has an equivalent mass.

According to a sixth aspect of the present invention, in the sound absorbing device according to any one of the first to fifth aspects, the low frequency sound absorbing material is laminated on the device side of the foam layer and the foam layer. A first porous body layer, and a second porous body layer laminated on the rigid wall layer side of the foam layer. The foam layer is a first diol having a molecular weight of 500 to 5000, a molecular weight of 500 or less. The second diol, inorganic filler, water as a foaming agent, and isocyanate components are used as raw material components.

According to a seventh aspect of the present invention, in the sound absorbing device according to any one of the first to fifth aspects, the low frequency sound absorbing material is laminated on the foam layer and the rigid wall layer side of the foam layer. A second porous body layer formed on the device side of the foam layer and a coating surface provided with a large number of holes on the device side of the foam layer. The first diol of 5000, the second diol having a molecular weight of 500 or less, the inorganic filler, water as a foaming agent, and isocyanate components are used as raw material components.

According to an eighth aspect of the present invention, in the sound absorbing device according to any one of the first to fifth aspects, the low frequency sound absorbing material is laminated on the foam layer and the rigid wall layer side of the foam layer. And the second porous body layer formed on the device side surface of the foam layer, and the coating surface having its own device side roughened by friction processing, the foam layer has a molecular weight of 500 to 5000 The first diol, the second diol having a molecular weight of 500 or less, the inorganic filler, water as a foaming agent, and isocyanate components are used as raw material components.

According to a ninth aspect of the present invention, in the sound absorbing device according to any one of the first to fifth aspects, the low frequency sound absorbing material is laminated on the foam layer and the rigid wall layer side of the foam layer. A second porous body layer having a molecular weight of 500 to 5000, and a second diol having a molecular weight of 500 or less. , Inorganic filler, water as a foaming agent, and isocyanate components are used as raw material components.

According to a tenth aspect of the present invention, in the sound absorbing device according to any one of the first to fifth aspects, the low frequency sound absorbing material is laminated on the foam layer and the rigid wall layer side of the foam layer. A second porous body layer and a coating layer in contact with the device side of the foam layer, the foam layer comprising a first diol having a molecular weight of 500 to 5000, a second diol having a molecular weight of 500 or less. Each component of diol, inorganic filler, water as a foaming agent, and isocyanate is used as a raw material component.

According to an eleventh aspect of the present invention, in the sound absorbing device according to any one of the first to fifth aspects, the low frequency sound absorbing material is laminated on the device side of the foam layer and the foam layer. The first porous body layer, the second porous body layer laminated on the rigid wall layer side of the foam layer, and the damping material layer disposed on the rigid wall layer side of the second porous body layer The foam layer is composed of a first diol having a molecular weight of 500 to 5000, a second diol having a molecular weight of 500 or less, an inorganic filler, water as a foaming agent, and isocyanate components as raw material components. is there.

According to a twelfth aspect of the present invention, in the sound absorbing device according to any one of the first to fifth aspects, the low frequency sound absorbing material includes a foam layer disposed on the device side, and a foam layer. The first porous body layer laminated on the device side, the second porous body layer laminated on the rigid wall layer side of the foam layer, and the rigid wall layer side of the second porous body layer A damping material layer, a second porous body layer and a constraining material layer disposed between the damping material layers, the foam layer is a first diol having a molecular weight of 500 to 5000, and having a molecular weight of 500 or less. Each component of the second diol, the inorganic filler, water as a foaming agent, and isocyanate is used as a raw material component.

According to a thirteenth aspect of the present invention, in the sound absorbing device according to any one of the first to fifth aspects, the low frequency sound absorbing material is a resin film made of silicon rubber or acrylic resin. And a porous body layer laminated on the rigid wall layer side of the resin film.

According to a fourteenth aspect of the present invention, in the sound absorbing device according to any one of the first to fifth aspects, the low-frequency sound absorbing material includes a resin film made of silicon rubber or acrylic resin, and a rigid resin film. A first porous body layer laminated on the wall layer side and a second porous body layer laminated on the device side of the resin film are provided.

According to a fifteenth aspect of the present invention, in the sound absorbing device according to any one of the first to fourteenth aspects, the device is constituted by a transformer.

  The sound absorbing device according to the first to sixteenth aspects of the present invention has the following effects.

  First, a device such as a transformer installed in a building such as an electric room is covered with a sound-absorbing cabinet having a part of the opening, and at least a low frequency is applied to the wall of the electric room at a position facing the opening. Since the sound absorbing material is installed, the noise generated from the transformer, etc., is effective by hitting the noise leaking from the open part at least once with the first low frequency sound absorbing material or the second low frequency sound absorbing material. Can be absorbed, and noise propagation into the dwelling unit can be suppressed.

  Secondly, a device such as a transformer installed in a building such as an electric room is covered with a sound absorbing cabinet having a part of the opening, that is, a position closest to a device such as a transformer as a sound source. By installing the sound absorption cabinet in the high frequency, it is possible to efficiently absorb the harmonic frequency noise generated from a device such as a transformer.

  Third, the sound absorption cabinet that covers the device such as the transformer can be unitized, and an existing metal pipe or frame for assembling and fixing the cable terminal connection portion disposed around the device such as the transformer. Because it can be assembled in a short period of time by using, etc., it is not necessary to stop the operation of the transformer when installing the sound absorbing cabinet, and the sound absorbing cabinet should be installed in a short time and at low cost. Can do.

  Fourth, it is possible to efficiently absorb low-order harmonic frequency noise generated from devices such as transformers by installing a low-frequency sound absorbing material at least on the wall surface of the electric chamber facing the open portion of the sound absorbing cabinet. As a result, the low-frequency sound absorbing material can be installed in a short period of time and at a low cost as compared with the conventional sound absorbing device in which the low-frequency sound absorbing material is installed on the entire wall surface and ceiling of the electric room.

  Fifth, the sound absorption cabinet is composed of a rigid wall layer having a predetermined mass (for example, an iron plate having a thickness of 2.0 mm) and a low-frequency sound absorbing material pasted on the sound source side (device side) of the rigid wall layer. That is, by arranging a rigid wall layer on the back side (the side opposite to the sound source side) of the low-frequency sound absorbing material, low-order harmonics in the 100 Hz and 200 Hz regions generated from devices such as transformers Frequency noise can be absorbed efficiently.

  Sixth, by using an open part provided in a part of the sound absorption cabinet, it is possible to discharge the thermal energy that is constantly dissipated from the transformer, and thus the transformer that causes the transformer to fail. Temperature rise can be prevented.

  Seventh, by providing an opening on the front side of the sound absorption cabinet, maintenance of devices such as transformers can be easily performed.

  Embodiments to which the sound absorbing device of the present invention is applied will be described below with reference to the drawings.

  FIG. 1 is a cross-sectional view showing an embodiment of a sound absorbing device according to the present invention.

  In the figure, a sound absorbing device according to the present invention covers a transformer 2 as a device for generating heat and sound installed in a rental room of an apartment or an electric room 1 of an office building, and a device such as the transformer 2. , A sound absorbing cabinet 4 having an open part 3 in part, a first low frequency sound absorbing material 5 affixed to a wall surface 11 of the electric chamber 1 facing the open part 3 of the sound absorbing cabinet 4, and a wall surface of the electric chamber 1 11 and a second low-frequency sound absorbing material 6 attached to the ceiling 12 close to 11.

  As shown in FIG. 2, the sound absorbing cabinet 4 includes a sound absorbing panel (hereinafter referred to as “first sound absorbing panel”) 41 disposed on the upper surface side of the transformer 2 and a sound absorbing panel disposed on the back side of the transformer 2. A panel (hereinafter referred to as “second sound absorbing panel”) 42, a sound absorbing panel (hereinafter referred to as “third sound absorbing panel”) 43 disposed on one side surface of the transformer 2, and the other of the transformer 2. The sound absorption panel (hereinafter referred to as “fourth sound absorption panel”) 44 is provided on the side surface side.

  As shown in FIG. 3, the first to fourth sound absorbing panels 41 to 44 are each provided with a rigid wall layer 7 having a predetermined mass and the inside of the rigid wall layer 7, that is, on the transformer 2 (see FIG. 1) side. It is comprised with the 3rd low frequency sound-absorbing material 8 stuck.

  The rigid wall layer 7 is made of a metal plate having a thickness of at least 1.6 mm, specifically, an iron plate having a thickness of 2.0 mm. Here, a metal plate having a thickness of at least 1.6 mm is used as the rigid wall layer 7 because a metal plate having a thickness of less than 1.6 mm cannot obtain a sufficient sound absorbing effect.

  The third low-frequency sound-absorbing material 8 is a material that exhibits excellent sound-absorbing characteristics in the low-frequency region of 100 Hz and 200 Hz, specifically, the first and second materials that have been developed and filed by the present inventors. Sound absorbing materials are suitable (Japanese Patent Application Nos. 2004-57089 and 2005-77593).

  Specifically, as shown in Japanese Patent Application No. 2004-57089, the first sound absorbing material is firstly a foam layer and a first porous body laminated on the device side of the foam layer. A second porous body layer laminated on the rigid wall layer side of the foam layer, the foam layer comprising a first diol having a molecular weight of 500 to 5000, a second diol having a molecular weight of 500 or less, Each component of the inorganic filler, water as a foaming agent, and isocyanate is used as a raw material component.

  Secondly, a foam layer, a second porous body layer laminated on the rigid wall layer side of the foam layer, and a plurality of pores formed on the device side of the foam layer on its own device side The foam layer is composed of a first diol having a molecular weight of 500 to 5000, a second diol having a molecular weight of 500 or less, an inorganic filler, water as a foaming agent, and isocyanate components. Is a raw material component.

  Thirdly, the foam layer, the second porous body layer laminated on the rigid wall layer side of the foam layer, and the device side of the foam layer are formed on the device side, and the own device side is roughened by friction processing. The foam layer comprises a first diol having a molecular weight of 500 to 5000, a second diol having a molecular weight of 500 or less, an inorganic filler, water as a blowing agent, and isocyanate components. This is a raw material component.

  Fourth, a foam layer, a second porous body layer laminated on the rigid wall layer side of the foam layer, and a coating layer adhered to the device side of the foam layer, The first diol having a molecular weight of 500 to 5000, the second diol having a molecular weight of 500 or less, an inorganic filler, water as a foaming agent, and an isocyanate component are used as raw material components.

  Fifth, the foam layer includes a foam layer, a second porous body layer laminated on the rigid wall layer side of the foam layer, and a coating layer in contact with the device side of the foam layer, Uses a first diol having a molecular weight of 500 to 5000, a second diol having a molecular weight of 500 or less, an inorganic filler, water as a foaming agent, and an isocyanate component as raw material components.

  Sixth, the foam layer, the first porous body layer laminated on the device side of the foam layer, the second porous body layer laminated on the rigid wall layer side of the foam layer, And a foam material layer comprising: a first diol having a molecular weight of 500 to 5000; a second diol having a molecular weight of 500 or less; and an inorganic filler. In addition, water as a foaming agent and each component of isocyanate are used as raw material components.

  Seventh, the foam layer, the first porous body layer laminated on the device side of the foam layer, the second porous body layer laminated on the rigid wall layer side of the foam layer, 2 is provided with a damping material layer disposed on the rigid wall layer side of the porous body layer 2 and a constraining material layer disposed between the second porous body layer and the damping material layer, and the foam layer has a molecular weight Each component of a first diol having a molecular weight of 500 to 5000, a second diol having a molecular weight of 500 or less, an inorganic filler, water as a foaming agent, and an isocyanate are used as raw material components.

Eighth, in the low-frequency sound-absorbing material according to any one of the first to seventh aspects, the density of the foam is 50 to 500 kg / m ³ .

  Ninth, in the low-frequency sound absorbing material according to any one of the first to eighth aspects, the ratio of the hydroxyl group content contained in the first diol to the hydroxyl group content contained in the second diol is 1 : 0.3 to 2.5.

  Tenth, in the low-frequency sound absorbing material according to any one of the first to ninth aspects, the content of the inorganic filler is 10 to 200 parts by weight with respect to 100 parts by weight of the first diol. Yes.

  Eleventh, in the low-frequency sound-absorbing material according to any one of the first to tenth aspects, the water content as the foaming agent is 2 to 5 parts by weight with respect to 100 parts by weight of the first diol. Has been.

  Twelfth, in the low-frequency sound-absorbing material according to any one of the first to eleventh aspects, the total content of hydroxyl groups in water as the first and second diols and the blowing agent, and the isocyanate content of the isocyanate The isocyanate index (NCO / OH), which is a ratio of the above, is in the range of 0.5 to 1.0.

  13thly, in the low frequency sound-absorbing material of any of the first to twelfth aspects, the isocyanate index is in the range of 0.6 to 0.9.

  14thly, in the low-frequency sound-absorbing material according to any one of the first to thirteenth aspects, the first diol is polyester polyol, polyether polyol, polybutadiene polyol, polyisoprene polyol, polyolefin polyol, polyacrylic. The diol is any diol selected from an acid ester polyol and a polycarbonate polyol.

  Fifteenth, in the low-frequency sound-absorbing material according to any one of the first to fourteenth aspects, the second diol is ethylene glycol, propylene glycol, butanediol, hexanediol, octanediol, decanediol, or the like. It is supposed to be any diol selected from aliphatic or aromatic systems such as N, N-bis (2-hydroxypropyl) aniline.

  Sixteenth, in the low-frequency sound absorbing material according to any one of the first to fifteenth aspects, the inorganic filler is carbon black, silica, calcium carbonate, mica, talc, magnesium oxide, aluminum oxide, hydroxide It is supposed to be any inorganic filler selected from magnesium and aluminum hydroxide.

  Seventeenth, in the low-frequency sound-absorbing material according to any one of the first to sixteenth aspects, the isocyanate is 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4 ′ diphenylmethane diisocyanate. , Carbodiimide-modified diphenylmethane diisocyanate, crude tolylene diisocyanate, crude diphenylmethane diisocyanate, p-phenylene diisocyanate, p-xylene diisocyanate, tetramethylene-1,4-diisocyanate. .

  Eighteenth, in the low-frequency sound-absorbing material according to any one of the first to seventeenth aspects, the porous body layer is any one of coarse wool felt, plant fiber felt, animal fiber felt, and synthetic fiber felt. Or a mixture thereof.

  Nineteenth, in the low-frequency sound absorbing material according to any one of the first to eighteenth aspects, the constraining material layer is made of a member having a large Young's modulus.

  20thly, in the low-frequency sound absorbing material according to any one of the first to nineteenth aspects, the constraining material layer is made of a metal material.

  Twenty-first, in the low-frequency sound-absorbing material according to any one of the first to twentieth aspects, the thickness of the constraining material layer is 0.1 to 2 mm.

  According to the above first sound-absorbing material, first, by providing the porous body layers on both sides of the foam layer, it is possible to improve the sound-absorbing characteristics in a low frequency region of 200 Hz or less, and secondly, By providing a hole or the like with a needle-like member in the surface film of the sound-absorbing material, the air permeability of the foam layer can be improved, and as a result, the sound absorption characteristics in the low frequency region can be improved. Third, the foam layer The degree of freedom of the product form can be improved by adhering / contacting a coating layer formed separately on the sound source side.

  Specifically, the second sound absorbing material is, as shown in Japanese Patent Application No. 2005-77593, firstly, a resin film made of silicon rubber and a porous layer laminated on the rigid wall layer side of the resin film. And a material layer.

  Second, it comprises a resin film made of silicon rubber, a porous body layer laminated on the rigid wall layer side of the resin film, and another porous body layer laminated on the device side of the resin film. .

Third, in the low-frequency sound-absorbing material that is the first aspect or the second aspect, the combustion heat generation amount of the resin film is 8 MJ / m ³ or less.

Fourth, in the low-frequency sound-absorbing material of any one of the first to third aspects, the combustion heat generation rate of the resin film is set to [200 kW / m ² ] · 10 sec or less.

  Fifth, in the low-frequency sound absorbing material according to any one of the first to fourth aspects, the resin film includes an inorganic compound.

  Sixth, in the low-frequency sound-absorbing material of the fifth aspect, the inorganic compound includes a compound containing any one of Si, Ca, Sr, and Ba or any one of the Si, Ca, Sr, and Ba. It consists of a mixture of compounds.

  Seventhly, in the low-frequency sound-absorbing material according to any one of the first to sixth aspects, the porous body layer is formed of a material having flame retardancy.

  Eighth, in the low-frequency sound absorbing material according to any one of the first to sixth aspects, the porous body layer is made of either glass wool, rock wool, or a mixture thereof.

  Ninth, in the low-frequency sound-absorbing material according to any one of the first to eighth aspects, the resin film is integrated with the porous body layer.

  Tenth, in the low-frequency sound absorbing material according to any one of the second to ninth aspects, the resin film is integrated with one of the porous body layer and the other porous body layer. Is.

  Eleventh, in the low-frequency sound absorbing material according to the ninth aspect or the tenth aspect, the resin film is integrated with the porous body layer and / or another porous body layer by adhesion.

  Twelfth, in the low-frequency sound absorbing material according to the ninth aspect or the tenth aspect, the resin film is integrated with the porous body layer and / or another porous body layer by heat fusion. .

  13thly, in the low frequency sound absorbing material of the 9th aspect or the 10th aspect, the resin film is integrated with the porous body layer and / or another porous body layer by the silicone graft reaction. .

  14thly, in the low frequency sound-absorbing material according to the 9th aspect or the 10th aspect, the resin film has a part of the resin film entering the pores of the porous body layer and / or another porous body layer. And are integrated with the porous body layer and / or other porous body layers.

  According to the above second sound absorbing material, first, since the sound absorbing material itself is provided with flame retardancy conforming to the flame retardant standard in the Building Standard Law, the sound absorbing material needs to be flame retardant. Second, since halogen-based flame retardants and lead-based compounds are not used as flame retardants, there is no risk of generating toxic gases during combustion, and environmental protection measures are taken. Third, in the case where the porous body layers are provided on both sides of the resin film, noise in a low frequency region of 200 Hz or less can be effectively absorbed, and fourthly, the resin film is porous. In the case of being integrated with the material layer, the degree of freedom of the product form can be improved.

  The first and second low-frequency sound absorbing materials 5 and 6 have the same configuration as the third low-frequency sound absorbing material 8 described above. However, in the first and second low-frequency sound absorbing materials 5 and 6, the rigid wall layer 7 constituting the sound absorbing cabinet 4 is substituted for the wall or ceiling of the electric chamber 1.

  The 1st-4th sound absorption panels 41-44 of such a structure can be unitized using the flame | frame (not shown) etc. which were arrange | positioned around the transformer 2. FIG. That is, normally, around the transformer 2, a metal pipe, a frame, and the like for assembling and fixing the terminal connection portion of the high-voltage cable are disposed. By using the metal pipe and the frame, the sound absorption cabinet 4 is used. Can be assembled in a short time on site.

  In this embodiment, by using a frame made of an iron angle or the like, it is assembled and fixed integrally so as to exhibit a substantially inverted L shape in a cross-sectional view. The open part 3 is provided on the front side of the transformer 2.

  Next, additional functions of the sound absorbing cabinet 4 and the first and second low frequency sound absorbing materials of the present invention will be described.

  1stly, in the sound absorption cabinet 4 of this invention, the temperature rise of the transformer 2 which always dissipates heat energy can be reduced by providing the open part 3 in the front side of the transformer 2. FIG. That is, in order to sufficiently exhibit the sound absorbing effect, it is desirable to completely cover the transformer 2 with a sealed sound absorbing cabinet. However, if the transformer 2 is completely covered with the sound absorbing cabinet, the heat generated from the transformer 2 will be described. There is a risk that the energy dissipation characteristics deteriorate, and as a result, the transformer 2 may break down due to the temperature rise of the transformer 2, but in the present invention, by providing the open part 3, the temperature rise of the transformer 2 can be suppressed. it can.

  2ndly, according to the sound-absorption cabinet 4 of this invention, the operation | work at the time of the maintenance of the transformer 2 can be easily performed by utilizing the open part 3 provided in the front side of the transformer.

  Thirdly, if the open section 4 is provided in a part of the sound absorption cabinet 4, noise generated from the transformer 2 is leaked from the open section 4, so that harmonic noise having a frequency doubled from the transformer is efficiently generated. In the present invention, the first low-frequency sound-absorbing material 5 is pasted on the wall surface 11 of the electric chamber 1 facing the open part 3 of the sound-absorbing cabinet 4 as described above. If necessary, the second low-frequency sound-absorbing material 5 is pasted only on the ceiling 12 side close to the wall surface 11 of the electric chamber 1, so that the harmonic noise leaking from the open portion 3 is at least once. The harmonic noise generated from the transformer 2 can be effectively absorbed by being applied to either the low frequency sound absorbing material 5 or the second low frequency sound absorbing material 6.

  Fourthly, in the above embodiment, the open part 3 is provided on the front side of the transformer 2, but the open part 3 is located farthest from the sound source of the transformer 2, for example, in another position of the sound absorption cabinet 4. It is preferable to provide at a different position. That is, for example, when the sound source is present on one side surface of the transformer 2, it is preferable to provide the open portion on the other side surface side of the transformer. According to the sound absorption cabinet having such a configuration, the noise generated from the transformer is effectively absorbed by the sound absorption cabinet disposed close to the sound source side, that is, the sound absorption cabinet disposed on the other side surface of the transformer. can do.

  FIG. 4 shows the measurement result of the noise level in the electric room when two 30 kVA transformers are installed in an electric room (4 m long × 3 m wide × 3 m high) having a concrete wall or ceiling.

  Here, as an example, the first to fourth sound absorbing panels are configured by attaching a third low frequency sound absorbing material of 75 mm thickness to an iron plate of 2.0 mm thickness, and this is formed around the transformer. A sound absorbing cabinet having a length of 3 m, a width of 2 m and a height of 2 m was assembled using a frame such as a steel frame. The sound absorbing cabinet encloses the transformer 2 so that the clearance with the transformer 2 is about 30 mm. In addition, the third low-frequency sound absorbing material 5 is attached to the wall surface 11 of the electric chamber 1 facing the open portion 3 of the sound absorption cabinet, and the section extending from the wall surface 11 to 1 m on the ceiling 12 adjacent to the wall surface 11 of the electric chamber 1 The second low-frequency sound-absorbing material 6 was used. Further, as a comparative example, a glass wool having a thickness of 75 mm was attached to all the wall surfaces and the ceiling of the electric room.

  The noise level was measured according to JIS A 1409: 1998 “Method for measuring sound absorption coefficient of reverberation room method”.

  From the figure, the sound absorbing device in the present embodiment is 30 dBA at the second harmonic (100 Hz) generated from the transformer and the fourth harmonic while shortening the installation period of the sound absorbing device compared to the comparative example. A dominant difference of 25 dBA is recognized at (200 Hz), and it can be seen that the sound absorbing device according to the present invention has a very effective characteristic for noise countermeasures of the transformer.

  The present invention can be changed and modified as follows within the scope of the claims.

  1stly, in the above-mentioned Example, although the case where the steel plate of thickness 2.0mm was used as a rigid wall layer was described, the rigid wall layer is a board | plate material which has the mass equivalent to the said iron plate, for example, thickness An aluminum plate having a thickness of about 5.0 mm may be used.

  Secondly, in the above-described embodiment, as the sound absorption cabinet, an open front side is used, but only one side is opened, only the front is opened, only the top is opened, You may use what opened only the back surface, or what combined these.

  Thirdly, in the above-described embodiment, the case where a resin film made of silicon rubber is used as the first, second, and third low-frequency sound absorbing materials is described. However, the resin film made of silicon rubber is used instead. Alternatively, a resin film made of an acrylic resin may be used.

  Fourthly, in the above-described embodiment, the case where the opening portion is provided in a part of the sound absorption cabinet is described. However, the opening portion may be provided with a porous plate so as to close the opening portion.

Explanatory drawing which shows one Example of the sound-absorbing device of this invention. Explanatory drawing which shows one Example of the sound-absorption cabinet in the sound-absorbing device of this invention. The side view which shows one Example of the sound absorption panel in the sound absorption cabinet of this invention. Explanatory drawing which shows the measurement result of the noise level in the sound-absorbing device of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Electric room 11 ... Wall surface 12 ... Ceiling 2 ... Transformer 3 ... Opening part 4 ... Sound absorption cabinet 5 ... 1st low frequency sound absorption material 6 ... 1st 2 low frequency sound absorbing material 7 ... rigid wall layer 8 ... third low frequency sound absorbing material

Claims (15)

A device for generating the installed thermal and sound in an electric chamber, the device was Tsutsumihi, and one side is opened sound-absorbing cabinet is affixed to the open part facing the wall of the sound absorbing cabinet of the electric room A first low-frequency sound absorbing material ,
The sound absorbing cabinet includes a rigid wall layer having a predetermined mass and a third low-frequency sound absorbing material attached to the device side of the rigid wall layer . A device for generating the installed thermal and sound in an electric chamber, the device was Tsutsumihi, and one side is opened sound-absorbing cabinet is affixed to the open part facing the wall of the sound absorbing cabinet of the electric room A first low-frequency sound absorbing material, and a second low-frequency sound absorbing material attached to the ceiling adjacent to the wall surface of the electrical chamber ,
The sound absorbing cabinet includes a rigid wall layer having a predetermined mass and a third low-frequency sound absorbing material attached to the device side of the rigid wall layer . The open section, the sound-absorbing device according to claim 1 or claim 2 wherein, characterized in that provided in the position farthest from the source of the device.   The sound absorbing device according to any one of claims 1 to 3, wherein the opening portion is provided on a front side of the device. The rigid wall layer is a metal plate having a thickness of at least 1.6 mm, or claims 1 to 4 any one, characterized by being composed of a plate material having the same mass and the metal plate The sound absorbing device as described. The low-frequency sound absorbing material includes a foam layer, a first porous body layer laminated on the device side of the foam layer, and a second laminate laminated on the rigid wall layer side of the foam layer. A porous body layer,
The foam layer is composed of a first diol having a molecular weight of 500 to 5000, a second diol having a molecular weight of 500 or less, an inorganic filler, water as a foaming agent, and isocyanate components as raw material components. The sound absorbing device according to any one of claims 1 to 5 . The low-frequency sound absorbing material is formed on the side of the device of the foam layer, the second porous body layer laminated on the rigid wall layer side of the foam layer, and the foam layer. A coating surface provided with a plurality of holes on the device side,
The foam layer is composed of a first diol having a molecular weight of 500 to 5000, a second diol having a molecular weight of 500 or less, an inorganic filler, water as a foaming agent, and isocyanate components as raw material components. The sound absorbing device according to any one of claims 1 to 5 . The low-frequency sound absorbing material is formed on the side of the device of the foam layer, the second porous body layer laminated on the rigid wall layer side of the foam layer, and the foam layer. The device side comprises a coating surface roughened by friction processing,
The foam layer is composed of a first diol having a molecular weight of 500 to 5000, a second diol having a molecular weight of 500 or less, an inorganic filler, water as a foaming agent, and isocyanate components as raw material components. The sound absorbing device according to any one of claims 1 to 5 . The low-frequency sound absorbing material includes a foam layer, a second porous body layer laminated on the rigid wall layer side of the foam layer, and a coating layer bonded to the device side of the foam layer; With
The foam layer is composed of a first diol having a molecular weight of 500 to 5000, a second diol having a molecular weight of 500 or less, an inorganic filler, water as a foaming agent, and isocyanate components as raw material components. The sound absorbing device according to any one of claims 1 to 5 . The low-frequency sound absorbing material includes a foam layer, a second porous body layer laminated on the rigid wall layer side of the foam layer, and a coating layer in contact with the device side of the foam layer And
The foam layer is composed of a first diol having a molecular weight of 500 to 5000, a second diol having a molecular weight of 500 or less, an inorganic filler, water as a foaming agent, and isocyanate components as raw material components. The sound absorbing device according to any one of claims 1 to 5 . The low-frequency sound absorbing material includes a foam layer, a first porous body layer laminated on the device side of the foam layer, and a second laminate laminated on the rigid wall layer side of the foam layer. A porous body layer, and a damping material layer disposed on the rigid wall layer side of the second porous body layer,
The foam layer is composed of a first diol having a molecular weight of 500 to 5000, a second diol having a molecular weight of 500 or less, an inorganic filler, water as a foaming agent, and isocyanate components as raw material components. The sound absorbing device according to any one of claims 1 to 5 . The low-frequency sound absorbing material includes a foam layer disposed on the device side, a first porous body layer laminated on the device side of the foam layer, and the rigid wall layer side of the foam layer A second porous body layer stacked on the hard wall layer side of the second porous body layer, the second porous body layer and the vibration damping material With a constraining material layer disposed between the layers,
The foam layer is composed of a first diol having a molecular weight of 500 to 5000, a second diol having a molecular weight of 500 or less, an inorganic filler, water as a foaming agent, and isocyanate components as raw material components. The sound absorbing device according to any one of claims 1 to 5 . The low-frequency sound absorbing material comprises a resin film made of silicon rubber or acrylic resin, claims 1 to 5, characterized in that it comprises a said resin film said rigid wall layer side porous layer laminated on the The sound absorbing device according to any one of claims. The low-frequency sound absorbing material is laminated on a resin film made of silicon rubber or acrylic resin, a first porous body layer laminated on the rigid wall layer side of the resin film, and the device side of the resin film. The sound absorbing device according to any one of claims 1 to 5, further comprising a second porous body layer. The apparatus acoustic absorber of claim 1 to claim 14 any one of claims, characterized in that a transformer.

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