JP2513809B2 - Silencer for cooling system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Field of Industrial Application) The present invention relates to a silencer used for a cooling device such as a refrigerator,
In particular, the present invention relates to a silencer for a cooling device that actively cancels noise from a machine room that houses a compressor.

(Prior Art) A cooling device using a compressor, for example, a refrigerator is often installed in a living room of a general household and is continuously operated regardless of the season. Noise reduction is an issue. In this case, the most problematic noise source of the refrigerator is noise from the machine room in which the compressor and the piping system connected to the compressor are stored. That is, in the machine room, the compressor itself generates relatively large noise (operation noise of the compressor motor, fluid noise due to compressed gas, mechanical noise in movable mechanical elements of the compression mechanism portion, etc.) and is connected to the compressor. The piping system also generates noise due to its vibration, and such machine room noise accounts for the majority of refrigerator noise. Therefore, suppressing the noise from the machine room greatly contributes to the noise reduction of the entire refrigerator.

Therefore, in the past, as measures to reduce noise from the machine room, in addition to noise reduction of the compressor itself (for example, adoption of a rotary type compressor), improvement of the vibration isolation support structure of the compressor and improvement of the shape of the piping system etc. By doing so, vibration can be damped in the vibration propagation path, or sound-absorbing members and sound-insulating members are placed around the compressor and piping system to increase sound absorption volume and increase noise transmission loss. Is being carried out.

(Problems to be Solved by the Invention) In general, a mechanical room of a refrigerator is provided with a plurality of openings for heat radiation in order to release heat generated by driving a compressor to the outside. Noise will leak from the outside. For this reason, the conventional noise reduction measures are naturally limited, and the noise level reduction effect can be expected to be only about 2 dB (A).

On the other hand, in recent years, with the development of electronics application technology, especially acoustic data processing circuits and acoustic control technology, the application of active noise control technology that reduces noise by utilizing the interference of sound waves has attracted attention. Has been done.
That is, this active control basically converts a sound from a noise source into an electric signal by a sound receiver provided at a specific position, and controls the electric signal based on a signal processed by an arithmetic unit. By operating the sound generator, an artificial sound having the same wavelength and the same amplitude as that of the original sound (sound from the noise source) is generated from the sound generator, and the original sound is interfered with by the original sound. Is to attenuate. However, when such active noise control is used to reduce machine room noise in a refrigerator, the machine room is in a non-sealed state and the noise generated in the machine room leaks freely in three dimensions. Because it is below
There is a problem that the active control mode becomes extremely complicated,
The fact is that practical use of active noise control in refrigerators is completely unclear.

The present invention has been made in view of the above circumstances, and an object thereof is to perform active control in which noise generated in response to driving of a compressor in a non-sealed machine room is canceled by interference with an artificial sound. It is an object of the present invention to provide a silencer for a cooling device that can simplify the active control and improve the control accuracy.

[Configuration of the Invention] (Means for Solving the Problem) In order to achieve the above-mentioned object, the present invention actively generates a sound generated by driving a compressor housed in a machine room by interference with an artificial sound. In the muffler of the cooling device that is designed to cancel, the machine room is configured to be closed except for the heat dissipation opening, and one dimension among the three-dimensional dimensions in the machine room is By setting it larger than the dimension of (1), the standing wave of the sound in the machine room is constituted so that only the first-order mode is established in the frequency band below the cancellation target (claim 1).

In such a configuration, the sound receiver can be arranged in the machine chamber so as to face the compressor from the side opposite to the heat radiation opening (claim 2).

In this case, it is preferable that the peripheral wall portion of the machine room is made of a material having excellent thermal conductivity and large sound transmission loss (claim 3).

Further, an outer shell is formed integrally with the cooling device main body, and the inside of the machine room partition surrounded by the outer shell is partitioned by one or more partition plates to form the machine room. May be used (claim 4).

When the partition plate is provided as described above, the control speaker can be attached and supported at the partition position (claim 5).

Further, in the case where the machine room is formed using the machine room compartment as described above, the parts other than the machine room in the machine room compartment are the parts housing for housing the electrical components for controlling the cooling device. It can also be configured as a chamber (claim 6).

In this case, the electrical component may be stored in the component storage chamber while being mounted and supported on the partition plate (claim 7).

(Function) For example, in a refrigerator, which is a typical example of a cooling device, in the case of a refrigerator having a general structure, the sound level of noise generated in response to the driving of the compressor is 700H as shown in FIG.
It has the property of increasing in the band of z or less and in the band of 1.5 to 5 KHz. Of the noises corresponding to each of these bands, those on the high frequency side can be easily silenced by the conventional noise reduction technique using a sound absorbing member or the like.
Therefore, when the active control of noise is actually performed, the noise on the low frequency side should be the target frequency (about 700 Hz or less in this case).

In this way, when the target frequency is about 700 Hz or less, two of the height, depth and width directions in the machine room are shorter than the wavelength of the original noise (about 50 cm at a sound speed of 340 m / sec) and the remaining one When the dimension in the direction is set longer than the above wavelength, the standing wave of noise generated in the machine room can be established only in the first mode. That is, by setting a dimension in one of the three-dimensional height, depth, and width directions in the machine room to be larger than the other dimensions, the frequency of the standing wave of sound in the machine room to be canceled ( Target frequency)
It can be configured so that only the first-order mode can be established below the band.In such a configuration, the sound generated in the machine room can be regarded as a one-dimensional plane traveling wave, and the sound and control The control for interfering with the artificial sound from the sound generator to suppress the sound can be performed easily and accurately both theoretically and technically. Of course, since the heat dissipation opening is provided in the machine room, there is no fear that the temperature inside the machine room will rise abnormally due to heat generated when the compressor is driven.

When the sound receiver is placed in the machine room so as to face the compressor from the side opposite to the heat dissipation opening,
Since the sound receiver is kept away from the heat dissipation opening, which is the main source of sound from the outside, the level of external sound input to the sound receiver through the heat dissipation opening is Is sufficiently lower than the level of the noise to be controlled that is input to the sound receiver, and as a result, it is possible to suppress the above-mentioned external sound from adversely affecting the silencing control system, such as causing it to malfunction. Like

In addition, if the surrounding wall of the machine room is made of a material with excellent thermal conductivity and large sound transmission loss, it can be expected to improve the efficiency of radiating the heat generated in the machine room and increase the internal temperature. Can be suppressed low, and the leakage of noise through the peripheral wall portion of the machine room can be suppressed.

When the machine room is constructed by partitioning the machine room compartment surrounded by the outer shell with a partition plate, the size of the machine room can be easily set, and the degree of freedom in design can be increased. Becomes higher.

When the control sounder is attached to and supported by the partition plate as described above, the back side of the sounder is surrounded by the outer shell, so unnecessary sound emitted from the back side of the sounder is generated. Is blocked by the outer shell, and therefore, generation of extra noise can be suppressed without using a complicated structure such as mounting the sound generator in a buried state.

When a part other than the machine room in the machine room compartment is used as the component storage room, the dead space generated by limiting the machine room to a specific shape can be effectively used. Further, in this case, when the electrical component is mounted and supported on the partition plate, it is not necessary to separately provide a special support member for supporting the electrical component, and the number of components can be reduced.

(Examples) Hereinafter, the first to third examples in which the present invention is applied to a refrigerator will be described, and prior to this, the principle of silencing by active control used in each example will be schematically described.

In FIG. 17, 1 is a noise source such as a compressor,
Reference numeral 2 denotes a control target point for which it is desired to muffle noise. The sound from the noise source 1 is converted into an electric signal by a sound receiver 3 such as a microphone, and this electric signal is passed through a calculator 4 including a filter or the like. The sound generator 5 such as a speaker is driven by the processed signal.

That is, the sound generated by the noise source 1 is S1, the sound generated by the speaker 5 is S2, the sound received by the sound receiver 3 is R1, the sound at the controlled point 2 is R2, and the above-mentioned sound output And the acoustic transfer function between each of the input points is T11, T21, T12, T22, the following equation holds as a 2-input 2-output system.

Therefore, the sound S2 that the speaker 5 should generate is S2 = (-T12 / R1 + T11 / R2) / (T11 / T22-T12 / T2) from the above equation.
1), but in this case, the target is to make the sound level at the controlled point 2 zero, so R2 =
It can be set to 0. As a result, S2 = R1 · T12 / (T12 · T21-T11 · T22). As can be understood from this equation, in order to reduce the sound R2 at the controlled point 2 to zero, the sound R1 received by the microphone 3 is filtered by F = T12 / (T12 ・ T21−T11 ・ T22). The sound level at the control target point 2 can theoretically be set to zero by generating the processed sound S2 from the speaker 5.

Therefore, FIGS. 1 to 3 show a first embodiment of the present invention, which will be described below.

That is, in FIG. 3 showing the entire configuration of the refrigerator, reference numeral 11 denotes a refrigerator main body which is a cooling device main body, and inside thereof, a freezing compartment 12, a refrigerating compartment 13 and a vegetable compartment 14 are provided in order from above. Reference numeral 15 is a cooler arranged at the back of the freezer compartment 12, and 16 is a fan for directly supplying the cool air generated by the cooler 15 to the freezer compartment 12 and the refrigerating compartment 13. Reference numeral 17 denotes a machine room formed in the lower portion of the rear side of the refrigerator main body 11, and inside the machine room, a rotary type compressor 18, a condenser pipe 19, and a defrosting water evaporation device 20 using a so-called ceramic fin are housed. .

By the way, as shown in FIG. 1 (the condenser pipe 19 and the defrosting water evaporator 20 are not shown here), the machine room 17 has a shape in which only the back surface thereof is opened in a rectangular shape. The opening is closed by the machine room cover 21. At this time, the machine room cover 21
The peripheral edge portion is airtightly attached to the opening edge portion of the machine room 17, and an elongated rectangular heat radiation opening portion 21a extending in the vertical direction is formed at the left edge portion in FIG. . That is, when the machine room cover 21 is attached, the machine room 17 is in a closed state except for the heat dissipation opening 21a. The machine chamber cover 21 is made of a material (for example, metal such as iron) that has excellent thermal conductivity and large sound transmission loss.

Reference numeral 22 denotes a sound receiver, for example, a microphone arranged in the machine room 17, which is arranged so as to face the compressor 18 from the side opposite to the heat dissipation opening 21a (right side in FIG. 1). Thus, the sound from the compressor 18, which is a noise source, is provided so as to be converted into an electric signal. Reference numeral 23 denotes a speaker, which is a control sound generator arranged in the machine room 17, and is located, for example, in a portion near the heat dissipation opening 21a in the back wall portion of the machine room 17 (corresponding to the bottom wall portion of the refrigerator body 11). Attached and supported. The speaker 23 is connected to the microphone 22.
It is designed to be operated by a signal obtained by processing an electric signal from a processing unit (not shown). The processing of the electric signal as described above is performed based on the silencing principle by the active control described above. There is.

Then, in the case of the refrigerator configured as described above, the noise level generated in the machine room 17 in response to the driving of the compressor 18 has a band of about 700 Hz or less and a band of 1.5 to 5 KHz as shown in FIG. Each of them has a property of increasing. Of the noise corresponding to each of these bands, the noise on the high frequency side can be attenuated by the transmission loss in the machine room cover 21 and the like, and can be easily provided by installing an appropriate sound absorbing member in the machine room 17. Since the noise can be muted, the active control of noise by the microphone 22, the speaker 23, and the calculator (not shown) as described above may be performed with a target frequency of 700 Hz or less.

Further, when performing active control of noise as described above, it is possible to configure the noise in the machine room 17 to be a one-dimensional plane traveling wave, both theoretically and technically. It becomes important for easy and accurate operation. Therefore, in this embodiment, for example, of the three dimensions D, W, and H in the depth, width, and height directions which are the three-dimensional directions in the machine room 17 shown in FIG. Set larger than dimensions D and H (specifically, W = 600m
m, D = H = 200mm)
It is constructed so that the standing wave of the sound within is established only in the first-order mode. That is, for example, assuming that the machine room 17 is a rectangular cavity, the following equation holds.

However, f is the resonance frequency (Hz), Nx, Ny, Nz are X, Y,
The second mode in each Z direction, Lx, Ly, and Lz are X in the machine room 17,
Dimensions in each of the Y and Z directions (that is, D, W, H) and C are sonic speeds. Therefore, from the above equation, 1 for each of the X, Y, and Z directions.
The frequencies fx, fy, and fz of the th standing wave can be obtained.

That is, as described above, when the depth dimension D = 200 mm, the width dimension W = 600 mm, and the height dimension H = 200 mm are set, the frequency fx of the first standing wave in the X direction is Ny.
= Nz = 0, speed of sound C = 340 m / sec, Similarly, the frequencies fy and fz of the first standing wave in the Y and Z directions are Becomes As a result, the target frequency (= 700Hz)
In the following, the standing wave of noise in the machine room 17 is established only in the Y direction (width direction) mode.
The noise inside can be regarded as a one-dimensional plane traveling wave. Therefore, at the time of noise reduction by active control of noise using the speaker 23 or the like, theoretical treatment of the wavefront becomes easy, and the noise reduction control can be performed easily and accurately. Of course, in this case, since the machine room 17 communicates with the outside through the heat dissipation opening 21a, the temperature inside the machine room 17 does not rise abnormally due to heat generated when the compressor 18 is driven.

Further, since the machine room cover 21 is made of a material having excellent thermal conductivity, the heat radiation efficiency of the heat generated in the machine room 17 is improved, and from this aspect, the temperature rise in the machine room 17 also increases. Will be held low. Moreover, since the machine room cover 21 is made of a material having a large sound transmission loss, it is possible to suppress the leakage of noise through the machine room cover 21.

Further, the microphone 22 is on the opposite side (right side in FIG. 1) from the heat dissipation opening 21a, which is the main source of intrusion of sounds from the outside (that is, sounds that adversely affect the active control system as described above). Is located at a position facing away from the heat dissipation opening 21a, the level of the external sound input to the microphone 22 through the heat dissipation opening 21a is input from the compressor 18 to the microphone 22. The noise level is sufficiently lower than the level of the controlled noise to be controlled, and as a result, it is possible to prevent the external sound from adversely affecting the active control system, such as causing it to malfunction.

A second embodiment of the present invention is shown in FIGS. 4 and 5, which will be described below. It should be noted that this embodiment is intended for a so-called comptop refrigerator in which a compressor is installed on the top of the refrigerator body.

That is, in FIG. 5, reference numeral 24 is a refrigerator main body which is a cooling device main body, in which a freezer compartment 25, a refrigerator compartment 26 and a vegetable compartment are provided.
27 are provided. 28 is a cooler arranged at the back of the freezer compartment 25, and 29 is a freezer compartment for directly generating cold air generated by the cooler 28.
A fan for supplying 25 and the refrigerating compartment 26, and 30 are condenser pipes arranged so as to extend from the back surface to the bottom surface of the refrigerator main body 24. In this case, the condenser pipe 30 is bent in a meandering shape at the bottom portion of the refrigerator main body 24 to form a heating unit for evaporating defrost water, and the evaporation dish 31 is placed on the heating unit. It is set up.

At the top of the refrigerator body 24, a rectangular container-shaped outer shell
A machine room compartment 33 is provided by integrally forming 32, and a decorative panel 33a flush with the freezer compartment door 25a is attached to the front surface of the machine room compartment 33. Then, in the machine room compartment 33, one partition plate
A front side component storage chamber 35 and a rear side machine chamber 36 are formed by partitioning the front and rear and airtightly by a machine chamber 36, and a compressor 37 is arranged in the machine chamber 36.

Then, as shown in FIG. 4, in the portion corresponding to the upper surface of the machine chamber 36 in the outer shell 32, in the front-back direction (that is, in the longitudinal direction of the machine chamber 36) toward the longitudinal edge of the machine chamber 36. An elongated rectangular heat dissipation opening 36a is formed extending in the (orthogonal direction), whereby the machine room 36 has a heat dissipation opening 36a.
It is in a closed state except for a.

At this time, as in the first embodiment, of the dimensions D, W and H in the depth, width and height directions in the machine room 36, the dimension W in the width direction is made larger than the other dimensions D and H. By setting (for example, setting W to 600 mm or more and D and H to about 200 mm), the standing wave of noise in the machine room 36 is established only in the width direction mode. In this case, the outer shell forming the peripheral wall portion of the machine room 36
The 32 and the partition plate 34 are formed of a material (for example, a metal such as iron) that has excellent thermal conductivity and has a large sound transmission loss. Further, in the component storage chamber 35, an electrical component 38 that constitutes a control circuit for a refrigerator is stored in a state of being placed on the bottom portion thereof.

Reference numeral 39 denotes a sound receiver, for example, a microphone arranged in the machine room 36, which is arranged so as to face the compressor 37 from the side opposite to the heat radiation opening 36a (right side in FIG. 4). Thus, the sound from the compressor 37, which is a noise source, is provided so as to be converted into an electric signal. Reference numeral 40 denotes a speaker, which is a control sound generator arranged in the machine room 36, and is embedded in a portion of the bottom wall of the machine room 36 (corresponding to the ceiling of the refrigerator body 24) near the heat dissipation opening 36a. It is attached and supported in a shape. The speaker 40 is operated by a signal obtained by processing the electric signal from the microphone 39 in the same manner as in the first embodiment (that is, a signal processed based on the above-mentioned noise active control principle). .

Therefore, according to the present embodiment configured as described above, it goes without saying that the same effects and advantages as the above-mentioned embodiments are achieved.
In addition, various effects as described below can be achieved. That is, the machine room 36 divides the machine room compartment 33 into partition plates 34.
Since it is configured by partitioning by, the dimension of the machine room 36 can be easily set, and the degree of freedom in designing the dimension is increased.

Further, since the machine room 36 is located in a place where it is not affected by the defrosting water that evaporates from the evaporation tray 31, the microphone 39
Also, there is no possibility that humidity will adversely affect the speaker 40, and the operational reliability of these can be kept good. Parts other than the machine room 36 in the machine room compartment 33 are parts storage rooms.
Since it is used as 35, the dead space caused by the machine room 36 being limited to a specific shape can be effectively used, and since the parts storage room 35 is located on the front side of the machine room 36, the internal electrical equipment The repair and repair work of the part 38 can be easily performed.

Although the speaker 40 is attached to the bottom wall of the machine room 36 in the second embodiment, the speaker 40 'is attached to and supported by the partition plate 34 as shown by the chain double-dashed line in FIG. It may be configured as a speaker.
The mounting structure of 40 'becomes simple compared to the case where it is buried. In this case, since the back side of the speaker 40 'is surrounded by the outer shell 32 made of a material having a large sound transmission loss, unnecessary sound radiated from the back side of the speaker 40' is put into the outer shell 32 '. By doing so, the noise is cut off, and the generation of extra noise is suppressed.

Further, in the second embodiment, the heat dissipation opening 36a is formed on the upper surface of the machine room 36, but as shown in FIG. 6, a portion of the outer shell 32 corresponding to the end face in the longitudinal direction of the machine room 36. And the elongated rectangular heat dissipation opening extending in the vertical direction of the machine room 36 (that is, the direction orthogonal to the longitudinal direction of the machine room 36).
36b may be formed, or as shown in FIG. 7, elongated rectangular heat radiation openings 36c may be formed at the corners of the end face, which extend in the vertical direction.

Furthermore, in the second embodiment, the partition 33 for the machine room is partitioned.
Although it is configured to be partitioned in the front-rear direction by 34, as shown in FIG. 8 or 9, the machine room compartment 33 is partitioned by the partition plate 34 in the left-right direction, so that the component storage room 35 ′ and the machine room 36. ′ May be formed.

FIG. 10 to FIG. 12 show a third embodiment of the present invention, and only the parts different from the second embodiment will be described below.

That is, in this embodiment, the partition 33 for the machine room is divided into two parts by the partition plates 41 and 42 in the front-rear and air-tight manners. A chamber 45 is formed, and a compressor 37 is arranged in the machine chamber 44. Further, in a portion of the outer shell 32 corresponding to the upper surface of the machine room 44, an elongated rectangular heat dissipation opening 44a extending in the front-rear direction is formed near the longitudinal edge of the machine room 44.

At this time, the relationship among the dimensions D, W, and H in the machine room 44 in the depth, width, and height directions is set in the same manner as in the second embodiment. The standing wave is configured to be established only in the widthwise mode.
In this case, the partition plates 41 and 42 are formed of the same material as the outer shell 32 (a material having excellent thermal conductivity and large sound transmission loss).

Further, in the parts storage chamber 43, the electrical components 38 are
It is stored in a state where it is mounted and supported on the
See figure). Then, the microphone 39 is connected to the compressor 37.
On the other hand, the speaker 40 is arranged so as to oppose from the side opposite to the heat dissipation opening 44a (right side in FIG. 10), and the speaker 40 is, for example, in a state where the front surface of the speaker 40 faces the machine room 44. Attached and supported.

According to this embodiment configured in this way, in addition to the same effects as those of the second embodiment, the mounting structure of the speaker 40 is simplified, and the adverse effects of unnecessary sound radiated from the back side of the speaker 40 are reduced. The outer shell 32 has the effect of being restrained. Further, according to this embodiment, since the electrical component 38 is attached and supported by the partition plate 41, it is not necessary to separately provide a member for supporting the electrical component 38, and the number of components can be reduced. Of course, since the machine room 44 is formed by using the two partition plates 41 and 42, the size of the machine room 44 can be set more easily. Moreover, in the machine room 44, the partition plates 41, 42 and the outer shell 32 are doubly present in the depth direction (front-back direction), so that the noise transmitted therethrough can be greatly reduced, and the noise reduction effect can be obtained. It can be further enhanced.

In the third embodiment described above, the heat dissipation opening 44a is formed on the upper surface of the machine room 44, but as shown in FIG. 13, it corresponds to the longitudinal end surface of the machine room 44 in the outer shell 32. The elongated rectangular heat dissipation opening that extends in the vertical direction of the machine room 44 (that is, the direction orthogonal to the longitudinal direction of the machine room 44).
It may be configured to form 44b. Further, as shown in FIG. 14, a machine room 44 is provided at a position near the edge of the partition plate 42.
And a rectangular elongated heat dissipation opening that communicates between the auxiliary chamber 45
44c is formed in a vertically oriented state, and at the corner portion of the outer shell 32, an elongated rectangular heat dissipation opening 45a for communicating the inside and outside of the auxiliary chamber 45 is formed in a vertically oriented state. It may be configured.

Furthermore, in the third embodiment, the partition 33 for the machine room is partitioned.
Although it is configured to be partitioned in the front-rear direction by 41 and 42, as shown in FIG. 15 or 16, the machine room compartment 33 is divided into partition plates 41 and 42.
The parts storage chamber 43 ', the machine chamber 44', and the auxiliary chamber 45 'may be formed by partitioning in the left-right direction or the diagonal direction.

Besides, the present invention is not limited to the embodiments described above and shown in the drawings, and for example, an outdoor unit of an air conditioner or a refrigerating showcase may be applied as a cooling device to be silenced. Various modifications can be implemented without departing from the above.

[Effects of the Invention] As is clear from the above description, according to the silencer of the cooling device of the first aspect, the machine chamber in which the compressor is housed is configured to be closed while leaving the heat radiation opening. By setting one of the three-dimensional dimensions of the machine room in one direction to be larger than the other dimensions, only the first-order mode is established below the frequency band at which the standing wave of the sound in the machine room is to be silenced. Since it is configured as described above, the active control is simplified when the active control is performed by canceling the noise generated by the driving of the compressor in the unsealed machine room by the signal sound from the control sounder. In addition, improvement of control accuracy can be realized.

According to the muffler of claim 2, the noise detecting sound receiver necessary for performing the active control as described above is mainly used for the external sound that adversely affects the active control of the compressor in the machine room. Since it is arranged so as to oppose from the side opposite to the heat dissipation opening, which is a large intrusion part, the level of external sound input to the sound receiver from the heat dissipation opening can be relatively lowered. There is an advantage that the active control system is less likely to malfunction due to the external sound.

Further, according to the muffler of the third aspect, the temperature rise in the machine room can be suppressed, and the adverse effect of heat on the motor winding of the compressor is less likely to occur, and the leakage noise through the peripheral wall portion of the machine room is suppressed. become able to.

According to the sound deadening device of the fourth aspect, the size of the machine room can be set according to the arrangement state of the partition plate, so that the size setting can be easily performed and the degree of freedom in design regarding the size setting becomes high.

According to the silencer of the fifth aspect, the mounting structure of the control sounding device can be simplified, and the generation of noise due to unnecessary sound radiated from the back side of the sounding device can be suppressed.

According to the sound deadening device of the sixth aspect, the dead space caused by the machine room being limited to a specific shape can be effectively used as the component storage chamber, and the repair work of the electrical components stored in the component storage chamber is simple. Can be realized.

According to the sound deadening device of the seventh aspect, it is not necessary to separately provide a special member for supporting the electrical component accommodated in the component storage chamber, and the number of components can be reduced.

[Brief description of drawings]

1 to 3 show a first embodiment of the present invention. FIG. 1 is a perspective view showing an essential part in an exploded state, and FIG. 2 is a view for explaining a dimensional relationship of the essential part. A schematic perspective view and FIG. 3 are vertical sectional views of the refrigerator. FIGS. 4 and 5 show a second embodiment of the present invention. FIG. 4 is a perspective view of an essential part and FIG. 5 is a view corresponding to FIG. Further, FIGS. 6 and 7 are equivalent to FIG. 4 showing a modified example of the second embodiment, and FIGS. 8 and 9 are main parts showing another modified example of the second embodiment. It is a schematic cross-sectional view. Furthermore, FIGS. 10 to 12 show a third embodiment of the present invention, and FIG. 10 is a view corresponding to FIG.
FIG. 11 is a view corresponding to FIG. 5, and FIG. 12 is a plan view of the refrigerator. 13 and 14 show a modified example of the third embodiment, which is equivalent to FIG. 10, and FIGS. 15 and 16 show another modified example of the third embodiment. It is a side view. And the
Figure 17 is a schematic block diagram showing the silencing principle by active control.
The figure is a noise level characteristic diagram. In the figure, 11 and 24 are the refrigerator body (cooling device body), 17, 36,
36 ', 44, 44' are machine rooms, 18, 37 are compressors, 20 is defrost water evaporator, 21 is machine room cover, 21a, 36a, 36b, 3
6c, 44a, 44b, 44c and 45a are heat dissipation openings, 22 and 39 are microphones (sound receivers), 23, 40 and 40 'are speakers (control sounders), 31 is an evaporating dish, and 32 is an outer shell. , 33 is the compartment for the machine room,
34, 41, 42 are partition plates, 35, 35 ', 43, 43' are component storage chambers, and 38 is an electrical component.

Claims (7)

(57) [Claims] 1. A machine room in which a compressor is housed, the sound generated when the compressor is driven is converted into an electric signal by a sound receiver, and the electric signal is processed by an arithmetic unit. In a silencer for a cooling device in which a sound emitted to the outside from the machine room is actively canceled by operating a control sounder based on a signal, the machine room is left with a heat dissipation opening. By setting the dimension in one direction out of each dimension in the three-dimensional direction in the machine room to be larger than the other dimension, the standing wave of the sound in the machine room is canceled. A silencer for a cooling device, characterized in that it is configured so that only a primary mode is established in a frequency band equal to or lower than that. 2. The noise device for a cooling device according to claim 1, wherein the sound receiver is arranged in the machine chamber so as to face the compressor from a side opposite to the heat radiation opening. 3. The silencer for a cooling device according to claim 1, wherein the peripheral wall portion of the machine room is made of a material having excellent thermal conductivity and large sound transmission loss. 4. A machine room having an outer shell integrally formed with a cooling device body and a compartment for a machine room surrounded by the outer shell, and the machine room includes one or a plurality of compartments for the machine room. The silencer for a cooling device according to claim 1, wherein the silencer is formed by partitioning with a partition plate. 5. The silencer for a cooling device according to claim 3, wherein the control sounder is attached to and supported by the partition plate. 6. The machine room compartment other than the machine room is configured as a parts housing room for housing electrical components for controlling the cooling device.
A silencer for the described cooling device. 7. The silencer for a cooling device according to claim 5, wherein the electrical component for controlling the cooling device is stored in the component storage chamber while being mounted and supported by the partition plate.