JP2014119148A - Air conditioner outdoor unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air conditioner outdoor unit capable of obtaining a sufficient soundproof effect against low frequency noise in a limited space around a compressor.SOLUTION: An air conditioner outdoor unit includes: a compressor 2; two Helmholtz resonance soundproof materials 7 arranged around the compressor 2, and constituting two Helmholtz resonators 20, respectively. By arranging the two Helmholtz resonators, a high soundproof effect can be obtained. This makes it unnecessary to arrange many resonators and makes it possible to increase a volume part of each resonator.

Description

  The present invention relates to an outdoor unit of an air conditioner.

  Conventionally, as a means for reducing noise generated from an outdoor unit of an air conditioner, a soundproof material has been provided around the compressor. The soundproofing material is generally configured by combining a rubber sheet and a felt material. Such a soundproofing material is designed so that the soundproofing effect is enhanced mainly at a frequency higher than 800 Hz. On the other hand, when such a soundproofing material is used for soundproofing a relatively low frequency noise of 800 Hz or less, an expensive soundproofing material having a low frequency absorption characteristic is used, or the thickness of the soundproofing material is increased. Although it is possible, there is a possibility that the manufacturing cost of the soundproofing material may increase. Therefore, for example, when the noise generated from the compressor has a peak at about 500 to 650 Hz, in order to reduce the noise, the manufacturing cost of the soundproof material has to be high.

  On the other hand, as a soundproofing material that is inexpensive and has a high soundproofing effect, there is known a soundproofing material that includes a plurality of Helmholtz resonators on the outer periphery of a compressor, as described in Patent Document 1. The Helmholtz resonator has a volume part formed by recessing a part of two resin materials bonded together, and an opening for communicating the inside and the outside of the volume part. In this resonator, when sound enters the volume through the opening, the sound is reduced by resonating with the subsequent sound inside the volume.

JP 2002243321 A

  However, it is difficult to reliably reduce low-frequency noise generated from the compressor with a structure in which a plurality of (specifically, eight) resonators are simply arranged as in the outdoor unit described in Patent Document 1. It is.

  Moreover, in the Helmholtz resonator as described above, in order to reduce low-frequency noise, it is necessary to enlarge the volume portion, so that it is difficult to secure an installation space with the arrangement disclosed in Patent Document 1. There's a problem.

  This invention is made in view of the above situations, and it aims at providing the outdoor unit which can acquire the sufficient soundproofing effect with respect to a low frequency noise in the limited space around a compressor. To do.

  The inventors of the present invention improve the soundproofing effect by installing two Helmholtz resonators around the compressor rather than one, and two or more when two or more are installed. It was discovered by experiment that the soundproofing effect is reduced more than that. Therefore, in the outdoor unit of the present invention, the number of Helmholtz resonators arranged around the compressor is limited to two, and an outdoor unit has been created that can reliably reduce low-frequency noise.

  That is, the outdoor unit of the present invention is an outdoor unit of an air conditioner, and is arranged around the compressor (2) and the compressor (2), and each of them constitutes a Helmholtz resonator (20). And a Helmholtz resonance type soundproofing material (7).

  According to this configuration, by arranging two Helmholtz resonance type soundproofing materials (7) around the compressor (2), one Helmholtz resonator or three or more Helmholtz resonators as in the past. It is possible to achieve a remarkable soundproofing effect that could not be achieved.

  Moreover, as described above, a high soundproofing effect can be obtained by arranging two Helmholtz resonators (20), so that it is not necessary to arrange a large number of the resonators, and the volume portion of each resonator (20) is reduced. It becomes possible to enlarge. As a result, a sufficient soundproofing effect against low-frequency noise can be obtained in a limited space around the compressor (2).

  The two soundproofing materials (7) may be arranged on only one of the opposing surfaces among a plurality of surfaces surrounding the compressor (2).

  According to such a configuration, since the two soundproofing materials (7) are disposed on only one of the opposing surfaces, a sufficient soundproofing effect can be obtained as compared with the case where each of the soundproofing materials (7) is disposed one by one on the opposing surface. There is no need to provide materials.

  Further, the two soundproof materials (7) may be arranged on the same surface among a plurality of surfaces surrounding the compressor (2).

  According to such a configuration, since the two soundproofing materials (7) are arranged on the same surface, the soundproofing effect is higher than when the two soundproofing materials (7) are arranged on the opposite surface, and the noise generated from the compressor (2) is increased. By arranging the two soundproofing materials (7) by selecting the largest direction of noise, it is possible to effectively suppress noise emitted in a specific direction. Therefore, for example, by arranging two soundproofing materials (7) on the front side of the outdoor unit, it is possible to effectively suppress noise emitted to the front side of the outdoor unit.

  Further, the two soundproofing materials (7) may be arranged on adjacent surfaces among a plurality of surfaces surrounding the compressor (2).

  According to such a configuration, the two soundproofing materials (7) are arranged on the surfaces adjacent to each other, so that the soundproofing effect is higher than the case where the two soundproofing materials (7) are arranged on the opposing surfaces, and the compressor (2) By selecting the direction of the loudest noise generated from the two and arranging the two soundproofing materials (7) close to each other, it is possible to select a sound in a specific direction and effectively perform soundproofing. Therefore, for example, even if there is no space for placing two soundproofing materials (7) on the front side of the outdoor unit, one soundproofing material (7) is placed on each of the front side of the outdoor unit and the side surface adjacent to it. By doing so, it is possible to effectively suppress the noise emitted to the front side and the side of the outdoor unit.

  In addition, the two soundproofing materials (7) are preferably set to dimensions capable of soundproofing in a frequency band of 400 to 800 Hz.

  According to such a configuration, the low frequency band in the range of 400 to 800 Hz out of the noise generated from the compressor (2) of the outdoor unit was a problem as low frequency noise, but the two soundproof materials (7) Since the optimum design is made to suppress low frequency noise, the soundproofing effect against the low frequency noise can be improved.

  As described above, according to the present invention, a sufficient soundproofing effect against low-frequency noise can be obtained in a limited space around the compressor.

It is a top view which shows the inside of the outdoor unit of the air conditioner concerning embodiment of this invention. It is a perspective view which shows the state by which the soundproofing material is each arrange | positioned at the front side and side surface side of the compressor of FIG. It is a perspective view of the soundproof material of FIG. It is sectional drawing of the soundproof material of FIG. It is a modification of embodiment of this invention, Comprising: It is a perspective view which shows the state by which two soundproof materials are arrange | positioned along with the front side of the compressor. It is a top view which shows typically the experimental model for investigating the soundproofing effect of the soundproofing material of this invention. It is an example of arrangement | positioning of the soundproof material in the experiment for investigating the soundproof effect of the soundproof material of this invention, Comprising: (a) is one soundproof material, (b)-(d) is two soundproof materials, (e ) Is a plan view showing an example in which three soundproofing materials and (f) are arranged with four soundproofing materials. It is a graph which shows the experimental result which conducted the experiment for investigating the soundproofing effect of the soundproofing material of this invention by arrangement | positioning of the soundproofing material shown by Fig.7 (a)-(f).

  Hereinafter, an outdoor unit of an air conditioner according to an embodiment of the present invention will be described in detail with reference to the drawings.

  As shown in FIGS. 1 and 2, the outdoor unit of the air conditioner includes a main body case 1, a compressor 2 that compresses the refrigerant, an outdoor heat exchanger 3 that performs heat exchange between the refrigerant and the outside air, A cooling fan 4 for cooling the outdoor heat exchanger 3, an accumulator 5, and a soundproof unit 10 for soundproofing the compressor 2 are provided.

  The compressor 2 has a plurality of legs 2a. The leg portions 2a are fixed to the bottom plate 1a of the main body case 1 via anti-vibration rubber or the like. An accumulator 5 that stores liquid refrigerant is connected to the suction port 2 b of the compressor 2. The discharge port 2 c of the compressor 2 is connected to a refrigerant pipe (not shown) piped above the compressor 2.

  The soundproof unit 10 includes a soundproof sheet 6 that surrounds the compressor 2 and the accumulator 5, and two Helmholtz resonance type soundproof materials 7 attached to the inner peripheral surface of the soundproof sheet 6.

  The soundproof sheet 6 surrounds the compressor 2 and the accumulator 5 and reduces noise generated from the compressor 2. The soundproof sheet 6 is made of a sheet-like material having sound absorbing properties such as a rubber sheet or a felt material.

  As shown in FIGS. 3 to 4, the soundproof material 7 is made of a flat member, specifically, a counter plate portion 7 a facing the compressor 2 that is a sound source, and a peripheral wall portion surrounding the counter plate portion 7 a. 7b, a flange portion 7c, and a cylindrical portion 7d. The opposing plate portion 7a is a rectangular flat plate and has an opening 7a1 at the center. The peripheral wall portion 7b extends in the direction opposite to the direction facing the compressor 2 from the four peripheral edges of the counter plate portion 7a. The flange portion 7c is provided on the peripheral edge of the peripheral wall portion 7b opposite to the counter plate portion 7a, and extends in parallel with the counter plate portion 7a. The cylinder part 7d is provided so as to protrude in the direction facing the compressor 2 from the peripheral edge of the opening 7a1 at the center of the counter plate part 7a. The soundproofing material 7 is configured by integrally forming the opposing plate portion 7a, the peripheral wall portion 7b, the flange portion 7c, and the cylindrical portion 7d.

  A flat concave portion 7e is formed by the counter plate portion 7a and the peripheral wall portion 7b surrounding the periphery thereof. The flange portion 7c is fixed to the soundproof sheet 7c by adhesion or the like, and the opening portion 7f of the concave portion 7e is closed by the inner peripheral surface of the soundproof sheet 6, whereby the space portion 8 is formed. The space portion 8 communicates with a space where the compressor 2 is installed (that is, a space surrounded by the soundproof sheet 6) through the through hole 7d1 inside the cylinder portion 7d.

  The two Helmholtz resonance type soundproofing materials 7 constitute Helmholtz resonators 20 by being attached to the inner peripheral surface of the soundproofing sheet 6 as shown in FIGS. Each Helmholtz resonator 20 has a structure including a space portion 8 and a cylindrical portion 7d communicating with the space portion 8. In the Helmholtz resonator 20, the resonance frequency f serving as a resonance attenuation target in the resonator 20 is determined by the volume V of the space portion 8, the opening area S of the cylindrical portion 7 d, and the length L of the through hole 7 d 1 of the cylindrical portion 7 d. .

That is, when the sound speed is c, the resonance frequency f is
f = (c / 2π) × √ (S / (L × V)) (Expression 1)

  Therefore, when the target frequency for which noise is to be suppressed is a low frequency, the volume V of the space portion 8 is increased, the length L of the cylindrical portion 7d is increased, or the resonance frequency f is decreased, It is necessary to reduce the opening area S of the cylindrical portion 7d. By adjusting these dimensions, in this embodiment, the two soundproofing materials 7 are set to dimensions capable of soundproofing in the frequency band of 400 to 800 Hz.

  In addition, although said soundproof material 7 has the cylinder part 7d which protrudes from the opposing board part 7a, this invention is not limited to this, The thickness of the opposing board part 7a is thick enough, When the Helmholtz resonator can be configured using the through-hole formed in the opposing plate portion 7a, the cylindrical portion 7d may be omitted.

  As shown in FIGS. 1 and 2, the two soundproofing materials 7 are arranged on only one of the opposing surfaces among a plurality of surfaces (four surfaces in the present embodiment) surrounding the compressor 2. . Specifically, as shown in FIGS. 1 and 2, four front surfaces surrounding the compressor 2, that is, the front surface of the front surface 11 a, the rear surface 11 b, the first side surface 11 c, and the second side surface 11 d, which are opposed to each other. One soundproof material 7 is disposed only on the front surface 11a of the 11a and the rear surface 11b, and the other soundproof material 7 is disposed only on the first side surface 11c of the first side surface 11c and the second side surface 11d facing each other. . The first side surface 11c faces the side surface 1b of the main body case 1 of the outdoor unit.

  As described above, the two soundproofing materials 7 are arranged on the front surface 11a and the first side surface 11c adjacent to each other among the four surfaces surrounding the periphery of the compressor 2, but a good soundproofing effect is obtained. It is preferable to arrange | position so that a mutual distance may become near. More preferably, the two soundproofing materials 7 are preferably arranged so that no noise generating portion in the compressor 2 is interposed between the cylindrical portions 7d where the sound enters. Most preferably, the two soundproofing materials 7 are preferably arranged so as to be in contact with the boundary portion between the adjacent front surface 11a and the first side surface 11c.

  In the outdoor unit of the above-described embodiment, two Helmholtz resonance type soundproof materials 7 are arranged around the compressor 2, so that one conventional Helmholtz resonator or three or more Helmholtz resonators is used. It is possible to achieve a remarkable soundproofing effect that could not be achieved.

  Moreover, as described above, a high soundproofing effect can be obtained by arranging the two Helmholtz resonators 20, so that it is not necessary to arrange a large number of the resonators 20 and the volume portions of the individual resonators 20 are enlarged. Is possible. As a result, a sufficient soundproofing effect against low frequency noise can be obtained in a limited space around the compressor 2.

  In addition, since it is not necessary to arrange a large number of resonators 20, it is possible to reduce manufacturing costs.

  Moreover, in the outdoor unit of this embodiment, since the two soundproofing materials 7 are arrange | positioned only at one side of an opposing surface, sufficient soundproofing effect is obtained rather than the case where it arrange | positions one piece at an opposing surface, and is more than necessary. It is not necessary to provide the soundproofing material 7.

  Moreover, in the outdoor unit of this embodiment, since the two soundproofing materials 7 are arrange | positioned at the mutually adjacent surface, respectively, the soundproofing effect becomes higher than the case where it arrange | positions in an opposing surface, and also the compressor 2 By selecting the direction of the largest noise generated from the two and arranging the two soundproofing materials 7 close to each other, it is possible to select a sound in a specific direction and effectively prevent sound. Therefore, for example, even when there is no space for arranging two soundproofing materials 7 on the front side of the outdoor unit, by arranging one soundproofing material 7 on each of the front side of the outdoor unit and the side surface adjacent thereto, It is possible to effectively suppress noise emitted to the front side and the side of the outdoor unit.

  Moreover, in the outdoor unit of this embodiment, since the two soundproofing materials 7 are set to the dimension which can be soundproofed in the frequency band of the range of 400-800 Hz, the noise generated from the compressor 2 of the outdoor unit is set. It is possible to effectively suppress the low frequency noise that is a problem, and to improve the soundproofing effect against the low frequency noise.

  In the above embodiment, the two soundproofing materials 7 are arranged on the adjacent surfaces. However, the present invention is not limited to this, and the two soundproofing materials 7 of the Helmholtz resonance type are arranged. Just do it.

  Therefore, as shown in FIG. 5, the two soundproofing materials 7 are all arranged on the same surface (for example, the front surface 11 a) among a plurality of surfaces (for example, four surfaces) surrounding the compressor 2. May be.

  In this case, since the two soundproofing materials 7 are arranged on the same surface, the soundproofing effect is higher than when the two soundproofing materials 7 are arranged on the opposite surface, and the direction of the largest noise generated from the compressor 2 is selected. By arranging the two soundproofing materials 7, it is possible to effectively suppress noise emitted in a specific direction. Thereby, as shown in FIG. 5, it is possible to effectively suppress the noise emitted to the front surface 11a side of the outdoor unit by arranging two soundproofing materials 7 on the front surface 11a side of the outdoor unit.

  Even in a structure in which two soundproofing materials 7 are arranged on the same surface as shown in FIG. 5, the two soundproofing materials 7 are arranged so as to be close to each other so as to obtain a good soundproofing effect. It is preferable. More preferably, it is preferable that the two soundproof materials 7 are arranged so as to contact each other.

  Further, in the modification shown in FIG. 5, when the two soundproofing materials 7 are arranged on the same surface among the plurality of surfaces surrounding the compressor 2, they are provided separately. The two soundproofing materials 7 may be formed by providing a partition inside the soundproofing material 7 and dividing the space into two spaces, and providing an opening communicating with each space. In this case, the two soundproof materials 7 are arranged so as to contact each other.

  Further, when the two soundproofing materials 7 are arranged on the same surface, not only the case where they are arranged side by side in the longitudinal direction (vertical direction in FIG. 5) of the compressor 2 as shown in FIG. 5 above. The compressor 2 may be arranged in parallel in the circumferential direction (lateral direction in FIG. 5).

(Experimental example)
Next, a test of the soundproofing effect when the number and arrangement of the soundproofing materials 7 are changed will be described with reference to FIGS.

  First, sampling is performed using a model as shown in FIG. In this model, the four sides of the sound source S, that is, the front surface 11a, the rear surface 11b, the first side surface 11c, and the second side surface 11d are surrounded by a soundproof sheet such as a felt material, and the soundproof material 7 is disposed on the inner surface of the soundproof sheet. Is. The microphone M for sound collection is arranged toward the front surface 11a. The sound source S is an omnidirectional sound source and generates sound uniformly on the four sides 11a to 11d.

  The example of arrangement | positioning of the soundproof material 7 is as showing to Fig.7 (a)-(f). Specifically, FIG. 7A illustrates an example in which one soundproof material 7 is attached to the front surface 11a of the sound source S, and FIG. 7B illustrates two soundproof materials 7 that are adjacent to the sound source S. FIG. 7C shows an example in which the two soundproofing materials 7 are attached to the opposing surfaces of the sound source S, that is, the front surface 11a and the rear surface 11b, respectively, and FIG. FIG. 7E shows an example in which two soundproof materials 7 are attached to the same surface, that is, the front surface 11a of the sound source S. FIG. 7E shows the three soundproof materials 7 on the front surface 11a, the rear surface 11b and the first side surface of the sound source S. FIG. 7 (f) shows an example in which four soundproof materials 7 are attached to the four sides of the sound source S, that is, the front surface 11a, the rear surface 11b, the first side surface 11c, and the second side surface 11d, respectively. It is shown.

  As a result of generating test sound from the sound source S for the example in which the soundproofing material 7 is not arranged and the example of the arrangement of the soundproofing material 7 shown in FIGS. 7A to 7F, the soundproofing sheet and the soundproofing material are obtained. The sound pressure level A (dB) of the noise that has passed through 7 and has gone out is as shown in curves I to VII of the graph of FIG. 8 with the frequency f (Hz) band as a reference. .

  As can be seen from the graph of FIG. 8, when the soundproofing material 7 is not disposed, as shown by the curve I, it can be seen that the sound pressure level is almost constant at all frequencies.

  When one soundproof material 7 in FIG. 7B is attached to the front surface 11a of the sound source S, as shown by the curve II, a specific frequency f0 (for example, the center frequency of the compressor noise and It can be seen that the sound pressure level slightly decreases in the vicinity of the same frequency).

  Here, if two or more soundproofing materials 7 are attached, the soundproofing effect will be improved over the curve II when one soundproofing material 7 is attached as described above, and the decrease in sound pressure level will be more pronounced. As expected, in the experimental results shown in the graph of FIG. 8, when two soundproofing materials 7 are attached (in the case of curves III, IV, and V), the sound pressure level is certainly higher than in the case of one. Although it decreases, it was found that the sound pressure level does not decrease when three or more are attached (in the case of curves VI and VII) as compared with the case of one.

  Here, the decrease in the sound pressure level becomes most noticeable near a specific frequency f0. The curve III (that is, the two soundproofing materials 7 in FIG. 8 is an example in which each of the first side surfaces 11c is attached) and a curve V (that is, an example in which the two soundproofing materials 7 in FIG. 7D are attached to the same surface, that is, the front surface 11a of the sound source S).

  Next, the decrease in the sound pressure level becomes remarkable when the two soundproofing materials 7 of curve III (that is, FIG. 7C) are attached to the opposing surfaces of the sound source S, that is, the front surface 11a and the rear surface 11b, respectively. Example).

  On the other hand, when three soundproof materials 7 are attached (in the case of curve VI) and when four soundproof materials 7 are attached (in the case of curve VII), the sound pressure level is lower than in the case of one. It can be seen from FIG.

  From the above results, the inventors of the present invention improved the soundproofing effect when installing two Helmholtz resonators 20 around the compressor 2, and improved the soundproofing effect. In this case, the experiment shows that the soundproofing effect is reduced more than two.

(Other variations)
As described above, in the present embodiment, the four surfaces are exemplified as the plurality of surfaces surrounding the compressor 2, but the present invention is not limited to this. Therefore, two soundproofing materials 7 may be arranged on the polygonal surface, and in that case, the soundproofing effect can be improved as compared with the case where one or three or more soundproofing materials 7 are arranged. It is.

  Further, even in the case of a polygonal surface, by arranging two soundproofing materials 7 on the same surface or adjacent surfaces as in the above-described embodiment, the soundproofing effect is remarkably compared with the case of other arrangements. It is possible to improve.

  Note that a part of such polygonal surfaces may include a curved surface.

DESCRIPTION OF SYMBOLS 1 Main body case 2 Compressor 7 Soundproofing material 10 Soundproofing part 20 Helmholtz resonator

Claims (5)

An air conditioner outdoor unit,
A compressor (2),
An outdoor unit provided with two Helmholtz resonance type soundproof materials (7) disposed around the compressor (2) and constituting Helmholtz resonators (20). The two soundproofing materials (7) are arranged on only one of the opposing surfaces among a plurality of surfaces surrounding the compressor (2).
The outdoor unit according to claim 1. Both of the two soundproof materials (7) are arranged on the same surface among a plurality of surfaces surrounding the compressor (2).
The outdoor unit according to claim 2. The two soundproof materials (7) are respectively disposed on adjacent surfaces among a plurality of surfaces surrounding the compressor (2).
The outdoor unit according to claim 2. The two soundproofing materials (7) are set to dimensions capable of soundproofing in a frequency band of 400 to 800 Hz.
The outdoor unit according to claim 1.

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