Soundproof structure for compressor

Abstract

Provided is a soundproof structure that soundproofs radiated sound emitted from an electric compressor (10) by a soundproofing member (1), and reduces deterioration of the soundproofing effect due to transmission of vibration of the compressor (10) to the soundproofing member (1). The soundproofing member (1) including a sound absorption layer (3) is installed to surround the compressor (10). A vibration transmission reduction member (5) is provided between the compressor (10) and the soundproofing member (1). The soundproofing member (1) is supported by the compressor (10) through the vibration transmission reduction member (5).

Description

Compressor soundproofing structure

[0001] The present invention relates to a soundproofing structure that suppresses the external emission of noise and vibrations generated by a compressor mounted on a vehicle.

[0002] Air conditioners for home appliances and electric vehicles use electric compressors, which house a compression mechanism for compressing a refrigerant and an electric motor for driving the compression mechanism, in a single housing. When the electric compressor is driven, noise is generated due to vibrations of the compression mechanism and motor, and pulsation of the refrigerant. A known method for suppressing the external emission of noise generated by the compressor during operation is to enclose the compressor in a soundproofing material.

[0003] Patent Document 1 discloses a soundproofing structure that covers the periphery of an electric compressor with a soundproofing material that combines a sound-absorbing material such as felt on the inner surface of a sound-insulating material such as a rubber sheet. This soundproofing structure also includes a case that supports the soundproofing material. The soundproofing material is supported on the inside of the case and is installed with a space between it and the compressor so that it does not come into contact with the surface of the compressor. This structure attenuates the sound radiated from the compressor by the soundproofing material and prevents compressor vibrations from coming into contact with the soundproofing material, which would impair the soundproofing effect.

[0004] Patent Document 2 discloses a soundproofing structure for an electric compressor used in a vehicle air conditioner. The electric compressor is covered by a resin case that has excellent vibration damping properties. The case also has mounting feet that allow bolts to be inserted through the case to mount the compressor to a mounting location on the vehicle. The compressor is supported by the case, and the case supporting the compressor is mounted to the mounting location on the vehicle. This allows the resin case to dampen the sound emitted from the electric compressor and prevents vibrations from the electric compressor from being directly transmitted to the mounting location on the vehicle.

[0005] JP 2004-143975 A JP 2012-202377 A

[0006] In the compressor soundproofing structure described in Patent Document 1, the compressor is fixed to a base, but the support case is simply placed on the base and is not fixed anywhere. This is likely because, as is clear from the diagram, the electric compressor described in Patent Document 1 is related to a home air conditioner and is intended for use in a stationary outdoor unit. For this reason, this soundproofing structure cannot be used in a vehicle air conditioner, which is subject to inertial forces caused by vehicle acceleration and deceleration.

[0007] In the soundproofing structure described in Patent Document 2, the electric compressor is attached to the vehicle via a soundproofing case. That is, the heavy electric compressor is supported by the inner circumferential surface of the soundproofing case. As a result, vibrations from the electric compressor are transmitted to the case, which may act as a speaker and generate radiated sound.

[0008] The present invention has been made to solve the above-mentioned problems, and aims to provide a soundproofing structure that uses soundproofing members to suppress the external dispersion of radiated sound emitted from an electric compressor used in a vehicle air conditioning system, and that reduces the transmission of compressor vibrations to the soundproofing members, thereby reducing the loss of soundproofing effect.

[0009] In the following description, reference numerals in the accompanying drawings are placed in parentheses to facilitate understanding of the present invention, but the present invention is not limited to the illustrated forms.

[0010] The soundproofing structure according to the present invention includes a soundproofing member (1) provided to surround a compressor (10) used in a vehicle air conditioning system and having a sound absorbing layer (3), and a vibration transmission suppression member (5) provided between the compressor (10) and the soundproofing member (1), and is characterized in that the soundproofing member (1) is supported by the compressor (10) via the vibration transmission suppression member (5).

[0011] Preferably, the vibration transmission suppression member (5) is divided into a plurality of pieces and arranged between the compressor (10) and the soundproofing member (1), and gaps are formed in the locations where the vibration transmission suppression member (5) is not arranged.

[0012] Preferably, the soundproofing member (1) further comprises an inner wall layer (4) on the inner periphery of the sound absorbing layer (3).

[0013] More preferably, the vibration transmission suppression member (5) is disposed between the inner wall layer (4) and the compressor (10).

[0014] More preferably, the soundproofing member (1) further comprises an outer wall layer (2) on the outside of the sound absorbing layer.

[0015] Preferably, the soundproofing member (1) has an opening (7) that does not cover the compressor (10), and the compressor (10) has an outer peripheral surface provided with mounting feet (20) through which a fastener can be inserted, and the mounting feet (20) are exposed through the opening (7).

[0016] According to the soundproofing structure of the present invention, it is possible to suppress the propagation of compressor vibrations to the soundproofing member, while also suppressing the external dispersion of radiated sound from the compressor by the soundproofing member.

[0017] Fig. 1 is an external view of an electric compressor according to an embodiment; Fig. 2 is an external view of the electric compressor shown in Fig. 1 equipped with a soundproofing device of the present invention; Fig. 3 is an axial cross-sectional view of the soundproofing structure shown in Fig. 2; Fig. 4 is a radial cross-sectional view of the soundproofing structure shown in Fig. 3, taken along section AA, as viewed from the compression mechanism side; Fig. 5 is a simplified axial cross-sectional view showing the soundproofing structure of a first embodiment; Fig. 6 is a simplified axial cross-sectional view showing the soundproofing structure of a second embodiment; Fig. 7 is a simplified axial cross-sectional view showing the soundproofing structure of a third embodiment;

[0018] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the accompanying drawings. Note that the embodiments shown in the accompanying drawings are merely examples of the present invention, and the present invention is not limited to these embodiments.

[0019] First Embodiment An electric compressor 10 (hereinafter, sometimes simply referred to as "compressor 10") according to a first embodiment and a soundproofing structure applied to this electric compressor 10 will be described with reference to FIGS. 1 to 5.

[0020] 1 shows an external view of an electric compressor 10 according to this embodiment. The electric compressor 10 is suitable for use in a refrigeration cycle that uses a refrigerant as a working fluid, such as in a refrigeration cycle of a vehicle air conditioner. However, the electric compressor 10 is not limited to a specific application.

[0021] The electric compressor 10 includes a compression mechanism that compresses a gas (e.g., a gaseous refrigerant), a motor that drives the compression mechanism, and an inverter that drives and controls the motor. The compression mechanism, motor, and inverter are housed within a housing 11 and constitute the compressor 10 as a compression mechanism section 10c, a motor section 10b, and an inverter section 10a, respectively.

[0022] The motor unit 10b and the compression mechanism unit 10c are housed in a cylindrical housing 11. The motor unit 10b has an outer peripheral surface provided with a suction port 15 for drawing refrigerant from the refrigeration cycle. The compression mechanism unit 10c has an outer peripheral surface provided with a discharge port 16 for discharging refrigerant compressed by the compression mechanism to the refrigeration cycle. Furthermore, the cylindrical housing 11 has three mounting feet 20 on its outer peripheral surface, through which mounting bolts (not shown) can be inserted as fasteners. The mounting feet 20 are made of a casting of a metal material such as aluminum (including aluminum alloys).

[0023] The inverter unit 10a has a box-like shape that extends radially outward from the outer periphery of the motor unit 10b. A connector 18 is provided on the end face of the radially extending portion facing the motor unit 10b to receive power and control signals from outside the compressor.

[0024] The motor is controlled by supplying power and control signals to the inverter via connector 18. When the motor drives the compression mechanism, refrigerant is sucked in cold through suction port 15, passes through the inside of housing 11, is compressed by the compression mechanism, and is discharged from discharge port 16. When the compressor is driven in this manner, various sounds and vibrations are emitted from compressor 10 due to the movement of the motor and compression mechanism, the flow and pressure pulsation of the refrigerant, and the driving of the inverter.

[0025] In the present invention, a soundproof structure is provided to suppress the noise and vibrations generated by the compressor from being released to the outside.

[0026] 2 shows an external view of the soundproofing structure that covers the electric compressor 10. The soundproofing member 1 has a shape that is slightly larger than the compressor 10, and has a cylindrical portion 8 that can house the compression mechanism portion 10c and the motor portion 10b, and an extension portion 9 that extends radially so as to house the inverter portion 10a.

[0027] The soundproofing member 1 has a plurality of openings 7 that do not cover the compressor 10. The suction port 15, the discharge port 16, the connector 18, and the mounting feet 20 are exposed through these openings 7. This allows refrigeration piping and a power cable to be connected while the compressor 10 is enclosed within the soundproofing member 1. Furthermore, the compressor 10 can be fixed to a mounting portion on the vehicle side by directly inserting bolts through the mounting feet 20.

[0028] The soundproofing member 1 can be separated into left and right halves with the connector 18 of the compressor 10 sandwiched between them. The separated left soundproofing member 1-L and right soundproofing member 1-R may be connected by a hinge (not shown). Alternatively, the outer peripheries of the combined soundproofing members 1-L and 1-R may be fastened with a cable tie without providing a connecting portion.

[0029] As shown in Figures 3 and 5, the soundproofing member 1 has a space therein for storing the compressor 10. The soundproofing member 1 includes a sound-absorbing layer 3 that has excellent sound-absorbing properties. The sound-absorbing layer 3 is made of a soft or semi-rigid foam, such as polyurethane foam. The air bubbles in the foam convert sound energy into heat, thereby suppressing sound emission to the outside of the soundproofing member 1.

[0030] The shape of the inner peripheral surface of the soundproofing member 1 is set to be larger than the outer peripheral surface of the compressor. Furthermore, a pad 5 serving as a vibration transmission suppression member is provided between the compressor 10 and the soundproofing member 1. In this embodiment, the pad 5 is attached to the inner peripheral surface of the sound absorbing layer 3 serving as the soundproofing member 1, but it may also be attached to the outer peripheral surface of the compressor 10. The presence of the pad 5 between the soundproofing member 1 and the compressor 10 prevents the soundproofing member 1 and the compressor 10 from coming into direct contact with each other.

[0031] As described above, the compressor 10 is fixed to a mounting location on the vehicle by bolts inserted through the mounting feet 20. On the other hand, the elastic member 1 simply covers the compressor 10 and is not fixed to the vehicle. Therefore, the elastic member 1 is supported by the compressor 10 via the pad 5.

[0032] The pads 5 are not provided on the entire inner circumferential surface of the soundproofing member 1, but are provided in a dispersed manner between the inverter unit 10a, the motor unit 10b, and the compression mechanism unit 10c of the compressor 10. FIG. 4 shows a cross-sectional view of the soundproofing structure shown in FIG. 3 taken along line AA, as viewed from the compression mechanism side. As shown in FIG. 4, the pads 5 are preferably attached at multiple locations in the circumferential direction. That is, the pads 5 are separated and disposed between the compressor 10 and the soundproofing member 1. The areas where no pads 5 are disposed are gaps, and the compressor 10 and the soundproofing member 1 are not in contact with each other. Distributing the pads reduces the number of vibration transmission paths between the compressor 10 and the soundproofing member 1, thereby suppressing vibration transmission.

[0033] The pads 5 are affected not only by the vibrations of the compressor 10 but also by the inertial load of the soundproofing material due to the acceleration / deceleration and vibrations of the vehicle, and by the pressing load on the compressor 10 due to the weight of the soundproofing material 1. Since the pressing load on the compressor 10 due to the weight of the soundproofing material 1 can only be supported by the pads provided on the upper side of the compressor, more pads 5 may be provided above the compressor 10 than below.

[0034] The pad 5 is made of a soft foam that is softer than the semi-hard or soft foam used in the sound-absorbing layer 3. A material that can be used for the foam is, for example, polyurethane foam. Because the hardness of the pad 5 is relatively low (soft), when an excitation force acts on the soundproofing material 1 due to vehicle vibrations or the like, the amplitude of the soundproofing material 1 suspended from the compressor 10 via the pad 5 is large. If the amplitude becomes too large, the soundproofing material 1 will come into contact with the compressor 10, so it is necessary to take care not to make the thickness of the pad 5 too thin. For example, if the specifications of the sound-absorbing layer 3 are: Target density: 40 to 200 kg / m ３ Target hardness: 1 N / mm ２ In this case, the specifications of the pad 5 are as follows: Target hardness: 0.5 N / mm２ By setting the thickness to 2 mm, it is possible to prevent the soundproofing material 1 from coming into contact with the compressor 10 and suppress the vibration of the compressor from being transmitted to the soundproofing material 1. In addition, the target hardness of the sound absorbing layer 3 is set to 0.5 N / mm ２ In this case, the target hardness of the pad 5 is set to 0.25 N / mm ２ It is preferable to do the following:

[0035] <Second embodiment> A schematic diagram of a second embodiment of the present invention is shown in Figure 6. The soundproofing material 1 of the second embodiment differs from the soundproofing material 1 of the first embodiment in that it further has an outer wall layer 2 on the outside of the sound absorbing layer 3. All other points are the same as those shown in the first embodiment, and therefore further description will be omitted.

[0036] The outer wall layer 2 is made of a hard resin or an olefin-based elastomer, and is provided so as to cover the outer peripheral surface of the sound-absorbing layer 3. The outer wall layer 2 does not have bubbles like the sound-absorbing layer 3, but is set to be harder than the sound-absorbing layer 3. For this reason, although its sound-absorbing properties are inferior, sound-blocking properties are expected. Therefore, by providing both the sound-absorbing layer 3 and the outer wall layer 2, soundproofing effects can be expected over a wider range of sounds.

[0037] <Third embodiment> A schematic diagram of a third embodiment of the present invention is shown in Figure 7. The soundproofing material 1 of the third embodiment differs from the soundproofing material 1 of the second embodiment in that it further has an inner wall layer 4 inside the sound absorbing layer 3. Other points are the same as those shown in the first and second embodiments, and therefore description thereof will be omitted.

[0038] The inner wall layer 4 is formed of a hard resin or olefin-based elastomer that is more rigid than the sound absorbing layer 3, and is provided along the inner peripheral surface of the sound absorbing layer 3. A pad 5 serving as a vibration transmission suppression member is provided on the inner peripheral surface of the inner wall layer 4. Because the inner wall layer 4 is more rigid than the sound absorbing layer 3, it can hold the pad 5 more stably than in the first embodiment.

[0039] The inner wall layer 4 is not required to have sound absorbing or sound insulating properties, and does not need to cover the entire inner peripheral surface of the sound absorbing layer 3. Therefore, the inner wall layer 4 can be made lightweight by appropriately thinning or leaving a void in the portion where the pad 5 is not installed.

[0040] The present invention is not limited to the above-described embodiments, and various combinations are possible. For example, in the third embodiment shown in Fig. 7, the soundproofing member 1 may be formed of only the sound-absorbing layer 3 and the inner wall layer 4, without providing the outer wall layer 2.

[0041] REFERENCE SIGNS LIST 1 soundproofing member 2 outer wall layer 3 sound absorbing layer 4 inner wall layer 5 vibration transmission suppression member 7 opening 8 extension 10 electric compressor (compressor) 10a inverter section 10b motor section 10c compression mechanism section 11 housing 15 suction port 16 discharge port 18 connector 20 mounting foot

Claims

1. A sound insulation structure for a compressor (10) used in a vehicle air conditioner, comprising: a sound insulation member (1) provided so as to surround the compressor (10) and having a sound absorption layer (3); and a vibration transmission suppression member (5) provided between the compressor (10) and the sound insulation member (1), wherein the sound insulation member (1) is supported by the compressor (10) via the vibration transmission suppression member (5).

2. The sound insulation structure for a compressor according to claim 1, wherein the vibration transmission suppression member (5) is arranged in a plurality of divided portions between the compressor (10) and the sound insulation member (1), and a gap is formed at a location where the vibration transmission suppression member (5) is not arranged.

3. The sound insulation structure for a compressor according to claim 1, wherein the sound insulation member (1) further comprises an inner wall layer (4) on the inner periphery of the sound absorption layer.

4. The sound insulation structure for a compressor according to claim 3, wherein the vibration transmission suppression member (5) is arranged between the inner wall layer (4) and the compressor (10).

5. The sound insulation structure for a compressor according to claim 1 or 2, wherein the sound insulation member (1) further comprises an outer wall layer (2) outside the sound absorption layer (3).

6. The sound insulation structure for a compressor according to claim 1, wherein the sound insulation member (1) has an opening (7) that does not cover the compressor (10), and an attachment foot portion (20) through which a fastener can be inserted is provided on the outer peripheral surface of the compressor (10), and the attachment foot portion (20) is exposed through the opening (7).

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