Soundproofing devices and compressors

Abstract

This soundproofing device is equipped with: a damping rubber plate which limits vibrations; a low-density felt material provided on the damping rubber plate; a high-density felt material which is provided on the low-density felt material and has a higher density than does the low-density felt material; and a resonant rubber plate which is provided on the high-density felt material and has a plurality of openings formed therein.

Description

[Technical field]

[0001] The present disclosure relates to a soundproofing device and a compressor for suppressing sound. [Background technology]

[0002] Conventionally, a commonly known soundproofing device has a structure in which sound-absorbing felt material that absorbs sound is attached to a vibration-damping rubber plate that suppresses vibration. When sound passes through the sound-absorbing felt material, friction occurs between the fibers, and the energy of the sound is converted into frictional heat, thereby reducing the sound. However, because low-frequency sounds have long wavelengths, the air vibrations that occur when the sound passes through the felt material are small. For this reason, sound-absorbing felt material has high sound-absorbing performance in the mid- and high-frequency ranges, but not in the low-frequency range.

[0003] Here, the operating noise of the compressor installed in the outdoor unit is one of the main causes of noise generated in the air conditioner, and has a wide range of frequency components. Even if a conventional soundproofing device is attached to the compressor, it is difficult to suppress low-frequency noise because the sound-absorbing performance of the sound-absorbing felt material is not high in the low-frequency range.

[0004] For the purpose of improving the sound absorption performance in the low frequency range, Patent Document 1 discloses a triple-layered soundproofing device in which a resonating rubber plate is attached to a sound-absorbing felt material and a vibration-damping rubber plate. The resonating rubber plate has openings at equal intervals, and when sound passes through the openings, the air present in the openings vibrates, generating friction, thereby absorbing low frequency sounds. This utilizes the mechanism of Helmholtz resonance, in which air compression occurs when sound with a specific frequency component passes through the openings of the resonating rubber plate, and rebound occurs due to the increase in internal pressure caused by the air compression, which occurs alternately. The air at the openings of the resonating rubber plate vibrates, generating friction between the vibration-damping rubber at the openings and the sound-absorbing felt material at the openings, reducing the sound. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2003-336940 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the soundproofing device disclosed in Patent Document 1, the thickness of the sound-absorbing felt material between the resonating rubber plate and the vibration-damping rubber plate affects the sound-absorbing performance, so in order to improve the sound-absorbing effect in the low-frequency range, the sound-absorbing felt material must be made thicker, which is costly. On the other hand, if you try to reduce costs by making the sound-absorbing felt layer thinner, the sound-absorbing effect in the low-frequency range becomes insufficient.

[0007] The present disclosure has been made to solve the above-mentioned problems, and provides a soundproofing device and compressor that enhances sound absorption in the low frequency range while maintaining sound absorption in the mid and high frequency ranges, without incurring additional costs. [Means for solving the problem]

[0008] The soundproofing device according to the present disclosure comprises a vibration-damping rubber plate that limits vibrations, a low-density felt material provided on the vibration-damping rubber plate, a high-density felt material provided on the low-density felt material and having a higher density than the low-density felt material, and a resonating rubber plate provided on the high-density felt material and having a plurality of openings formed therein. Effect of the Invention

[0009] According to the present disclosure, a low-density felt material and a high-density felt material having a higher density than the low-density felt material are provided. Therefore, even if the high-density felt material is made thin to reduce costs, the sound absorption performance is higher than that of a low-density felt material of the same thickness. Therefore, by using the high-density felt material in the part with high sound absorption effect, it is possible to increase the sound absorption effect in the low-frequency range while maintaining the sound absorption effect in the mid-frequency range and the high-frequency range without increasing costs. [Brief description of the drawings]

[0010] [Figure 1]1 is a circuit diagram showing an air conditioner according to a first embodiment. [Diagram 2] 1 is a perspective view showing a machine room of an outdoor unit according to a first embodiment. [Diagram 3] 1 is a top view showing a machine chamber of an outdoor unit according to Embodiment 1. FIG. [Figure 4] 1 is a side cross-sectional view showing a soundproofing device according to a first embodiment. [Diagram 5] 1 is a perspective view showing a soundproofing device according to a first embodiment, as viewed from the front side. [Figure 6] 1 is a perspective view showing a soundproofing device according to a first embodiment, as viewed from the rear side. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the soundproofing device of the present disclosure will be described with reference to the drawings. Note that the present disclosure is not limited to the embodiment described below. In addition, the size relationship of each component in the following drawings, including FIG. 1, may differ from the actual one. In addition, in the following description, terms indicating directions are appropriately used to facilitate understanding of the present disclosure, but these terms are for explaining the present disclosure and do not limit the present disclosure. Examples of terms indicating directions include "up", "down", "right", "left", "front" and "rear".

[0012] Embodiment 1 Fig. 1 is a circuit diagram showing an air conditioner 1 according to embodiment 1. The air conditioner 1 is a device that adjusts the air in a space to be air-conditioned, and as shown in Fig. 1, is equipped with an outdoor unit 2 and an indoor unit 3. The outdoor unit 2 is equipped with, for example, a compressor 6, a flow path switching device 7, an outdoor heat exchanger 8, and an outdoor blower 9. The indoor unit 3 is equipped with, for example, an expansion section 10, an indoor heat exchanger 11, and an indoor blower 12.

[0013] The compressor 6, the flow switching device 7, the outdoor heat exchanger 8, the expansion section 10, and the indoor heat exchanger 11 are connected by the refrigerant piping 5 to form the refrigerant circuit 4. The compressor 6 sucks in a refrigerant in a low-temperature and low-pressure state, compresses the sucked refrigerant, and discharges it as a refrigerant in a high-temperature and high-pressure state. The compressor 6 is, for example, a capacity-controllable inverter compressor. The flow switching device 7 switches the direction in which the refrigerant flows in the refrigerant circuit 4, and is, for example, a four-way valve. The outdoor heat exchanger 8 exchanges heat between, for example, outdoor air and the refrigerant. The outdoor heat exchanger 8 acts as a condenser during cooling operation, and acts as an evaporator during heating operation. The expansion section 10 is a pressure reducing valve or an expansion valve that reduces the pressure of the refrigerant and expands it. The expansion section 10 is, for example, an electronic expansion valve whose opening is adjustable.

[0014] The indoor heat exchanger 11 exchanges heat between, for example, indoor air and a refrigerant. The indoor heat exchanger 11 acts as an evaporator during cooling operation and as a condenser during heating operation. The indoor blower 12 is a device that sends indoor air to the indoor heat exchanger 11.

[0015] (Operation mode, cooling operation) Next, the operation modes of the air conditioner 1 will be described. First, the cooling operation will be described. In the cooling operation, the refrigerant sucked into the compressor 6 is compressed by the compressor 6 and discharged in a high-temperature, high-pressure gas state. The high-temperature, high-pressure gas refrigerant discharged from the compressor 6 passes through the flow switching device 7 and flows into the outdoor heat exchanger 8 acting as a condenser, where it is heat exchanged with the outdoor air sent by the outdoor blower 9, condensing and liquefying. The condensed liquid refrigerant flows into the expansion section 10, where it expands and is decompressed to become a low-temperature, low-pressure gas-liquid two-phase refrigerant. The gas-liquid two-phase refrigerant flows into the indoor heat exchanger 11 acting as an evaporator, where it is heat exchanged with the indoor air sent by the indoor blower 12, evaporating and gasifying. At this time, the indoor air is cooled, and cooling is performed in the room. The evaporated refrigerant in a low-temperature, low-pressure gas state passes through the flow switching device 7 and is sucked into the compressor 6.

[0016] (Operation mode, heating operation) Next, the heating operation will be described. In the heating operation, the refrigerant sucked into the compressor 6 is compressed by the compressor 6 and discharged in a high-temperature, high-pressure gas state. The high-temperature, high-pressure gas state refrigerant discharged from the compressor 6 passes through the flow path switching device 7 and flows into the indoor heat exchanger 11 acting as a condenser, where it exchanges heat with the indoor air sent by the indoor blower 12, condenses and liquefies. At this time, the indoor air is warmed, and heating is performed in the room. The condensed liquid state refrigerant flows into the expansion section 10, where it expands and is decompressed to become a low-temperature, low-pressure gas-liquid two-phase refrigerant. The gas-liquid two-phase refrigerant then flows into the outdoor heat exchanger 8 acting as an evaporator, where it exchanges heat with the outdoor air sent by the outdoor blower 9, evaporates and gasifies. The evaporated low-temperature, low-pressure gas state refrigerant passes through the flow path switching device 7 and is sucked into the compressor 6.

[0017] The air conditioner 1 does not have to have the flow path switching device 7. In this case, the air conditioner 1 becomes a cooling-only machine or a heating-only machine. In this embodiment 1, the expansion section 10 is provided in the indoor unit 3, but the expansion section 10 may be provided in the outdoor unit 2. The expansion section 10 may be provided in both the indoor unit 3 and the outdoor unit 2. In this case, the expansion section 10 of the indoor unit 3 has a function of expanding and decompressing the refrigerant to put it into a gas-liquid two-phase state, and the expansion section 10 of the outdoor unit 2 has a function of suppressing backflow of the refrigerant when multiple outdoor units 2 are combined.

[0018] (Machine room 2a) Fig. 2 is a perspective view showing a machine room 2a of the outdoor unit 2 according to embodiment 1. The outdoor unit 2 is partitioned into an air blower chamber (not shown) in which the outdoor blower 9 and the like are provided, and a machine room 2a in which the compressor 6 and the like are provided. As shown in Fig. 2, the machine room 2a is surrounded by a wall 2b, and the compressor 6 extending in the vertical direction is placed therein. Here, a soundproofing device 20 is provided on the compressor 6 and the wall 2b.

[0019] Fig. 3 is a top view showing the machine room 2a of the outdoor unit 2 according to the first embodiment. As shown in Fig. 3, three soundproofing devices 20 are provided on the outer periphery of the compressor 6. Each of the three soundproofing devices 20 is bent into an arc shape at an angle of about 120°, and each end is faced to each other to form a pseudo-circular shape. In this way, the three soundproofing devices 20 are wrapped around the entire outer periphery of the compressor 6. The soundproofing device 20 provided on the wall 2b is provided along the wall 2b.

[0020] (Soundproofing device 20) Fig. 4 is a side cross-sectional view showing the soundproofing device 20 according to embodiment 1. As shown in Fig. 4, the soundproofing device 20 includes a vibration-damping rubber plate 30, a low-density felt material 40, a high-density felt material 50, and a resonating rubber plate 60.

[0021] (Vibration-damping rubber plate 30) The vibration-damping rubber plate 30 serves to limit vibration and is a plate material made of elastic rubber.

[0022] (Low density felt material 40) The low-density felt material 40 is a sound-absorbing felt material with a relatively low density. The low-density felt material 40 is provided on the other surface of the vibration-damping rubber plate 30. When sound passes through the low-density felt material 40, friction occurs between the fibers, and the energy of the sound is converted into frictional heat to reduce the sound. For this reason, the low-density felt material 40 has high sound absorption performance in the mid-range and treble ranges. In the present embodiment 1, the low-density felt material 40 has a box shape 41. As a result, an air layer 42 in which air flows is formed inside the low-density felt material 40. In addition, the thickness of the bottom surface 40a of the low-density felt material 40 is equal to or greater than a predetermined thickness threshold. In this way, the bottom surface 40a of the low-density felt material 40 of the box shape 41 has a thickness, so that the sound absorption performance in the mid-range and treble ranges can be ensured.

[0023] (High density felt material 50) The high-density felt material 50 is a sound-absorbing felt material having a higher density than the low-density felt material 40. The high-density felt material 50 is provided on the low-density felt material 40. Like the low-density felt material 40, the high-density felt material 50 generates friction between fibers when sound passes through it, converts the energy of the sound into frictional heat, and reduces the sound. Therefore, like the low-density felt material 40, the high-density felt material 50 also has high sound absorption performance in the mid-range and treble ranges. Here, the thickness of the high-density felt material 50 is thinner than the thickness of the low-density felt material 40. The low-density felt material 40, the air layer 42, and the high-density felt material 50 are collectively referred to as the air flow layer 70.

[0024] (Resonating rubber plate 60) FIG. 5 is a perspective view showing the soundproofing device 20 according to the first embodiment, as seen from the front. The resonating rubber plate 60 is a plate material made of elastic rubber provided on the high-density felt material 50 and having a plurality of openings 61 formed therein. As shown in FIG. 5, the resonating rubber plate 60 has openings 61 formed at equal intervals, and when sound passes through the openings 61, the air present in the openings 61 vibrates, generating friction, and realizing sound absorption in the low-frequency range. This utilizes the mechanism of Helmholtz resonance, in which the compression of air that occurs when sound having a specific frequency component passes through the openings 61 of the resonating rubber plate 60 and the rebound caused by the increase in internal pressure due to the compression of the air alternately occur. The air in the openings 61 of the resonating rubber plate 60 vibrates, generating friction between the vibration-damping rubber plate 30 in the openings 61 and the high-density felt material 50 in the openings 61, thereby reducing the sound. Here, one surface of the resonating rubber plate 60 is attached to the compressor 6 or the wall 2b, etc., so that the soundproofing device 20 is attached to the compressor 6 or the wall 2b, etc. A felt material or the like may be interposed between the resonating rubber plate 60 and the compressor 6. This makes it possible to suppress the inhibition of air vibrations, compared to the case where the resonating rubber plate 60 is attached in close contact with the compressor 6.

[0025] Fig. 6 is a perspective view showing the soundproofing device 20 according to the first embodiment as seen from the back. The vibration-damping rubber plate 30 is omitted in Fig. 6. As shown in Fig. 6, the soundproofing device 20 has a plurality of box shapes 41. Rather than forming one large box shape 41, the soundproofing device 20 is divided into a plurality of small box shapes 41 in this way, thereby ensuring the strength of the soundproofing device 20.

[0026] According to the first embodiment, the low-density felt material 40 and the high-density felt material 50 having a higher density than the low-density felt material 40 are provided. Therefore, even if the high-density felt material 50 is made thin to reduce costs, the sound absorbing performance is higher than that of the low-density felt material 40 of the same thickness. Therefore, by using the high-density felt material 50 in the part with high sound absorbing effect, it is possible to improve the sound absorbing performance in the low-frequency range while maintaining the sound absorbing performance in the mid-frequency range and the high-frequency range without increasing costs. When sound passes through the resonating rubber plate 60, the soundproofing device 20 generates a resonant vibration in which the air in the opening 61 vibrates. The opening 61 causes the air to flow greatly due to the compression of the air generated when the sound is transmitted. Therefore, by lining the resonating rubber plate 60 with the high-density felt material 50 having a high sound absorbing performance, the frictional heat generated increases more than when the same volume of a normal felt material with a low density is used. Therefore, the sound absorbing performance in the low-frequency range is improved.

[0027] Furthermore, the thickness of the high-density felt material 50 is thinner than the thickness of the low-density felt material 40. In general, the price of the high-density felt material 50 is higher than the price of the low-density felt material 40. By reducing the thickness of the high-density felt material 50, it is possible to inexpensively increase the frictional heat generated when air passing through the openings 61 of the resonating rubber plate 60 vibrates.

[0028] Furthermore, the low-density felt material 40 has a box shape 41. This allows the volume of the air layer 42 formed in the low-density felt material 40 to be increased at low cost. When the air layer 42 expands, the frequency at which sympathetic vibration occurs becomes smaller, so that it is possible to adjust the material to cause sympathetic vibration in the low-frequency range. Since it is not necessary to thicken the low-density felt material 40 in order to improve the sound absorption performance in the low-frequency range, the amount of low-density felt material 40 used can be reduced.

[0029] The thickness of the bottom surface 40a of the low-density felt material 40 is equal to or greater than a predetermined thickness threshold value, thereby ensuring the thickness of the low-density felt material 40 that absorbs mid-range and treble sounds with short wavelengths.

[0030] As explained above, by combining felt materials having two densities, it is possible to obtain a higher sound absorbing performance than by using a felt material of uniform density. Generally, density and cost are proportional to each other. Therefore, by minimizing the amount of high-density felt material 50 used and adjusting the thickness of the inexpensive low-density felt material 40, it is possible to reduce costs. In other words, it is possible to obtain low-frequency sound absorbing performance by the resonating rubber plate 60 at low cost while maintaining the mid-frequency and high-frequency sound absorbing performance of the felt material. [Explanation of symbols]

[0031] 1 air conditioner, 2 outdoor unit, 2a machine room, 2b wall, 3 indoor unit, 4 refrigerant circuit, 5 refrigerant piping, 6 compressor, 7 flow path switching device, 8 outdoor heat exchanger, 9 outdoor blower, 10 expansion section, 11 indoor heat exchanger, 12 indoor blower, 20 soundproofing device, 30 vibration-damping rubber plate, 40 low-density felt material, 40a bottom surface, 41 box shape, 42 air layer, 50 high-density felt material, 60 resonating rubber plate, 61 opening, 70 air flow layer.

Claims

1. A vibration-damping rubber plate that limits vibration; A low-density felt material provided on the vibration-damping rubber plate; a high-density felt material provided on the low-density felt material and having a higher density than the low-density felt material; a resonating rubber plate provided on the high-density felt material and having a plurality of openings; A soundproofing device comprising:

2. The thickness of the high density felt material is less than the thickness of the low density felt material.

2. The soundproofing device according to claim 1.

3. The low density felt material is box shaped.

3. The soundproofing device according to claim 1 or 2.

4. The thickness of the bottom surface of the low density felt material is greater than or equal to a predetermined thickness threshold.

3. The soundproofing device according to claim 1 or 2.

5. The soundproofing device according to claim 1 or 2 Equipped with a compressor.

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