KR20210119835A - Noise Reduction Device and Electronic Device - Google Patents

Abstract

A noise reduction device comprising a housing having one open surface and a cavity therein; a sound-absorbing plate covering the open surface of the housing; and a plurality of sound-absorbing holes formed in the sound-absorbing plate, wherein the housing includes a first case facing the one surface and a second case positioned between the first case and the sound-absorbing plate to surround the cavity, can be implemented to match the shape of a noise-generating part, and the sound-absorbing plate can be formed in a curved surface corresponding to the shape of a noise source, thereby being easy to apply.

Description

Noise Reduction Device and Electronic Device

The present invention relates to a noise reduction device and an electronic device.

A laundry treatment apparatus is a generic term for an apparatus for washing clothes, an apparatus for drying clothes, and an apparatus capable of both washing and drying clothes.

Among the conventional laundry treatment apparatuses capable of drying clothes, a drum providing a space for storing clothes, a duct forming a flow path for re-supplying air discharged from the drum to the drum, and air introduced into the duct from the drum A first heat exchanger that cools to remove moisture contained in the air, a second heat exchanger that heats the air that has passed through the first heat exchanger, and a fan that moves the air that has passed through the second heat exchanger to the drum there was. It is possible to remove moisture from the clothes located in the drum by using the dry high-temperature air passing through the first heat exchanger and the second heat exchanger.

A clothes treatment apparatus capable of drying is light in weight because the number of parts is relatively small compared to a laundry treatment apparatus for washing, so that the rigidity of the support structure in the lower part is not greatly required. When a metal material is used for the base located at the bottom, air cooling of the compressor part is impossible, and there is a risk of corrosion in a humid environment inside the dryer. In addition, in some cases, it is mounted on the upper portion of the laundry treatment apparatus for washing, and in order to lighten the relative weight, it is common to use a light structure such as plastic for the base.

Main components, such as a compressor, a heat exchanger, and a fan, mounted on the laundry treatment apparatus are located below the laundry treatment apparatus and operate at high speed, which may cause noise. In particular, since the motor is driven while rotating, there is a problem in that a large noise is generated and is radiated to the front and rear surfaces of the laundry treatment apparatus.

Korea Publication No. 20170019117 relates to a noise-blocking device using a sound-absorbing panel, and more specifically, a noise-blocking device using a sound-absorbing panel that is installed in the connecting passage of a railroad vehicle and can effectively absorb noise generated during the operation of a railroad vehicle. However, since it uses countless small coplanar spaces, the manufacturing cost is high, the weight is heavy, and it is difficult to implement in a curved space or a narrow space.

Korean Public Publication No. 20170019117A

An object of the present invention is to shield a noise of a motor by enclosing a noise source of a laundry treatment apparatus in order to solve the above-described problem.

a housing having an open side and a cavity therein; a sound-absorbing plate covering the open surface of the housing; and a plurality of sound-absorbing holes formed in the sound-absorbing plate, wherein the housing includes: a first case facing the one surface; and a second case positioned between the first case and the sound-absorbing plate to surround the cavity.

The sound-absorbing plate may include a curved surface.

The first case is a cylindrical member, the second case is a donut-shaped plate-shaped member positioned on both sides of the cylinder and having an opening in the middle, and the sound-absorbing plate includes a cylindrical member positioned in the opening of the second case. can

A distance between the first case and the sound-absorbing plate is constant, and the second case may include a donut-shaped member having a constant width.

The distance between the first case and the sound-absorbing plate is different depending on the location, and the second case may include a donut-shaped member having a different width depending on the location.

The housing may include a plurality of housings having different distances between the sound absorbing plate and the first case, and the plurality of housings may be arranged in an annular shape.

The size of the sound-absorbing plate may be smaller than the size of the first case.

cabinet; Cylindrical motor providing rotational force; and a noise reduction device surrounding the outer circumferential surface of the motor, wherein the noise reduction device includes: a sound-absorbing plate in contact with the outer circumferential surface of the motor and formed with a sound-absorbing hole; The sound absorbing plate is coupled to one surface, and provides an electronic device including a housing including a cavity formed therein.

The housing may include: a first case spaced apart from the sound-absorbing plate by a predetermined distance; and a second case covering between the first case and the sound-absorbing plate to form the cavity.

The sound absorbing plate may have a cylindrical shape surrounding the outer circumferential surface of the motor, and the noise reduction device may have a donut shape surrounding the outer circumferential surface of the motor.

The noise reduction device of the present invention can be implemented according to the shape of the noise-generating part, and the sound-absorbing plate can be formed in a curved surface corresponding to the shape of the noise source, so it is easy to apply.

In addition, the cavity inside the housing uses an empty space, so there is no need for a partition wall inside like a Helmholtz resonator, so manufacturing cost is reduced and the weight is light.

Further, further scope of applicability of the present invention will become apparent from the following detailed description. However, it should be understood that the detailed description and specific embodiments such as preferred embodiments of the present invention are given by way of illustration only, since various changes and modifications within the spirit and scope of the present invention may be clearly understood by those skilled in the art.

1 and 2 show an example of a laundry treatment apparatus.
3 illustrates an example of a heat exchange unit and a washing unit provided in the laundry treatment apparatus.
4 is a view showing a motor equipped with a noise reduction device.
5 is a diagram illustrating an example of a noise reduction device.
FIG. 6 is a graph showing the sound absorption coefficient and the noise level of the noise reduction device shown in FIG. 5 .
7 and 8 are views showing another embodiment of the noise reduction device.

Hereinafter, a preferred embodiment of a laundry treatment apparatus and a control method thereof will be described in detail with reference to the accompanying drawings. The configuration or control method of the apparatus to be described below is only for explaining examples of the laundry treatment apparatus and the control method thereof, and is not intended to limit the scope of the invention, and the same reference numbers used throughout the specification indicate the same configuration represent elements.

1 and 2 show an example of the laundry treatment apparatus 100 . As shown in FIG. 2 , the laundry treatment apparatus 100 includes a cabinet 1 , a drum 2 rotatably provided inside the cabinet to provide a space for storing clothes, and discharge from the drum 2 . A duct (3) forming a flow path for re-supplying the exhausted air to the drum (2), and a heat exchange unit (4) for dehumidifying and heating the air introduced into the duct (3) and re-supplying it to the drum (2) includes

As shown in FIG. 1 , the cabinet 1 includes a front panel 11 forming a front surface of the laundry treatment apparatus. The front panel 11 has an inlet provided to communicate with the drum 2 . 111 and a door 112 rotatably coupled to the cabinet to open and close the inlet 111 may be provided.

A control panel 117 is provided on the front panel 11, and the control panel 117 includes an input unit 118 for receiving a control command from a user, and a display unit 119 for outputting information such as a control command selectable by the user. ) may be provided.

The input unit 118 includes a power supply request unit for requesting power supply to the laundry treatment apparatus, a course input unit for allowing a user to select a desired course from among a plurality of courses, and an execution request unit for requesting the start of the course selected by the user. can be provided. The display unit 119 may be provided to include at least one of a display panel capable of outputting text and figures, and a speaker capable of outputting a voice signal and sound.

As shown in FIG. 2 , when the drum 2 is provided with a cylindrical drum body 21 having an open front surface and a rear surface, respectively, the front surface of the drum 2 is located inside the cabinet 1 . A first support part 17 for rotatably supporting the , and a second support part 19 for rotatably supporting the rear surface of the drum 2 may be provided.

The first support part 17 is provided to penetrate the first fixed body 171 fixed inside the cabinet 1 and the first fixed body to communicate the inlet 111 and the inside of the drum body 21 . It may be provided to include a drum inlet 173, a first support body 175 that is provided on the first fixed body 171 and is inserted into the front surface (first open surface) of the drum body 21 . .

The first fixed body 171 may have any shape as long as the drum inlet 173 and the first support body 175 can be provided. The first support body 175 may be provided in a pipe shape protruding from the first fixed body 171 toward the drum body 21, and the diameter of the first support body 175 is the drum inlet. It may be set larger than the diameter of 173 and smaller than the diameter of the front surface of the drum body 21 . In this case, the drum inlet 173 will be located inside the space formed by the first support body 175 .

The first support unit 17 may be provided to further include a connecting body 177 connecting the inlet 111 and the drum inlet 173 . The connection body 177 may be provided in a pipe shape extending from the drum inlet 173 toward the inlet 111 . The connection body 177 may be provided with an air outlet 178 communicating with the duct 3 . As shown in FIG. 3 , the air outlet 178 is a passage that allows the air inside the drum body 21 to move to the duct 3 , and is provided to pass through the connection body 177 . It may be provided alone.

As shown in FIG. 2 , the second support part 19 is provided on a second fixed body 191 fixed inside the cabinet 1 and the second fixed body 191 to the drum body 21 . It may be provided to include a second support body 195 inserted into the rear surface (second open surface) of the. The second support part 19 is provided with an air inlet 198 which is provided to pass through the second fixed body 191 and communicates the inside of the drum body 21 with the inside of the cabinet 1 . In this case, the duct 3 may be provided to connect the air outlet 178 and the air inlet 198 .

The drum body 21 having an empty cylindrical shape can be rotated through various types of driving units, and FIG. 2 shows a motor 23 in which the driving unit is fixed inside the cabinet 1, a pulley rotating by the motor ( 25), a case in which the belt 27 is provided to connect the circumferential surface of the pulley 25 and the circumferential surface of the drum body 21 is illustrated as an example.

In this case, the first roller 179 for rotatably supporting the circumferential surface of the drum body 21 is provided on the first support part 17 , and the second support part 19 has the circumferential surface of the drum body 21 . A second roller 199 for rotatably supporting the may be provided.

The duct 3 includes an exhaust duct 31 connected to the air outlet 178, a supply duct 33 connected to the air inlet 198, and a connecting duct 35 connecting the exhaust duct and the supply duct. may be provided to do so.

The heat exchange unit 4 may be provided as a variety of devices capable of sequentially performing dehumidification and heating of the air introduced into the duct 3, and a case in which the heat exchange unit is provided as a heat pump will be described as an example. can do.

The heat exchange unit 4 includes a fan 49 for moving air along the duct 3, a first heat exchanger for removing moisture from the air introduced into the duct 3 (heat absorbing unit 41), and the duct (3) it is provided inside and includes a second heat exchanger (heating unit, 43) for heating the air that has passed through the first heat exchanger (41).

The fan 49 may be provided to include an impeller 491 provided inside the duct 3 and an impeller motor 493 for rotating the impeller 491 . The impeller 491 may be provided in any of the exhaust duct 31 , the connection duct 35 , and the supply duct 33 , FIG. 3 shows that the impeller 491 is provided in the supply duct 33 . The case (the case where it is located behind the heat generating part) is shown as an example.

The heat absorbing part 41 is provided with a plurality of metal plates disposed along the width direction (Y-axis direction) of the connection duct 35 or the height direction (Z-axis direction) of the connection duct, and the heating part 43 may be provided with a plurality of metal plates disposed along a width direction of the connection duct or a height direction of the connection duct. The heat absorbing part 41 and the heat generating part 43 are sequentially disposed in the connection duct 35 in the direction from the exhaust duct 31 to the supply duct 33, and form a circulation path of the refrigerant. They are connected to each other through a refrigerant pipe 48 to form.

The refrigerant moves along the refrigerant pipe 48 by the compressor 45 located outside the duct 3 , and the refrigerant pressure of the refrigerant passing through the heat generating unit 43 is applied to the refrigerant pipe 48 . A pressure regulator 47 for adjusting is provided.

The heat absorbing part 41 is a means for cooling the air and evaporating the refrigerant by transferring the heat of the air introduced into the exhaust duct 31 to the refrigerant. The heat generating unit 43 is a means for heating the air and condensing the refrigerant by transferring the heat of the refrigerant that has passed through the compressor 45 to the air. In this case, moisture contained in the air will be collected on the bottom surface of the connection duct 35 along the surface of the heat absorbing part 41 when passing through the heat absorbing part 41 .

In order to collect the water removed from the air passing through the heat absorbing part 41 , the laundry treatment apparatus 100 is provided with a water collecting part. FIG. 3 illustrates an example in which the water collecting part 37 is positioned inside the connecting duct 35 .

The water collecting parts 371 and 372 of FIG. 3 may be provided as a water collecting body 371 which is fixed to the bottom surface of the connecting duct 35 and communicates with the inside of the connecting duct. A heat exchanger support part 372 may be further provided inside the water collecting body 371 so that the heat absorbing and heat generating parts 41 and 43 do not come into contact with the water (condensate) stored in the water collecting body 371 . The heat exchanger support 372 is a spacer ( 375), and a support plate through hole 376 provided to pass through the support plate 373 may be provided.

The support plate through-hole 376 may be provided only in the space in which the heat absorbing part 41 is supported among the spaces provided by the support plate 373 , and is provided in the space in which the heat absorbing part is supported and the space in which the heat generating part is supported, respectively. could be If the support plate through hole 376 is also provided in the lower portion of the heating part 43, the water that has moved to the heating part 43 along the support plate 373 may be discharged to the water collecting body 371 (the heating part to prevent deterioration of heat transfer efficiency that occurs when in contact with water).

In order to minimize the accumulation of foreign substances (lint, etc.) discharged from the drum body 21 on the heat absorbing part 41 and the heat generating part 43 , the clothes treatment apparatus 100 has a filtration unit that filters air. can be provided. 3 illustrates a case in which the filtering unit is provided with a first filtering unit 5 provided in the connection duct 35 and a second filtering unit 8 provided in the exhaust duct 31 as an example.

The second filtering unit 8 is provided as a means for filtering the air flowing into the exhaust duct 31 from the drum body 21 , and the first filtering unit 5 is the second filtering unit 8 . ) and positioned between the heat absorbing part 41 and may be provided as a means for filtering the air passing through the second filtration part. The diameter of the filtration hole provided in the first filtration unit 5 may be set smaller than the diameter of the filtration hole provided in the second filtration unit 8 .

The second filtering unit 8 includes a frame 81 that is detachably inserted into the exhaust duct 31 through the air outlet 178, and a filter (fourth filter, 83) provided in the frame to filter air. ) can be provided.

The first filtering unit 5 may be detachably provided in the connection duct 35 . In this case, the front panel 11 of the cabinet is provided with a filter mounting hole 113 (refer to FIG. 1) from which the first filter unit 5 is drawn out and a mounting hole door 114 for opening and closing the filter mounting hole, and , the duct 3 may be provided with a duct through-hole 34 (refer to FIG. 3) into which the first filtering unit 5 is inserted. Accordingly, the user can remove the foreign substances remaining in the first filter unit 5 and wash the first filter unit after separating the first filter unit 5 from the laundry treatment apparatus as needed.

1 and 3, the first filtration part 5 is inserted into the filter mounting hole 113 and the duct through hole 34, and the second filtration part 8 and the heat absorbing part ( 41), the filter body (51, 53, 57, 58) positioned between, and the fluid (air and water) provided in the filter body and moving to the heat absorbing part 41 and the water collecting body 371 is filtered It may be provided to include a filter (531, 551, 571).

The first filter unit 5 may be provided to communicate with the exhaust duct 31 through the upper surface or the second side surface 58 of the filter unit body. 1 shows the exhaust duct 31 through an upper surface through-hole through which the first filter unit 5 penetrates through the upper surface of the filter body and a side through-hole through a second side surface 58 through the second side surface 58. It is illustrated as an example when connected to .

As shown in FIG. 2 , in the laundry treatment apparatus 100, a washing unit 6 for washing the first filter unit 5 using water stored in the water collecting body 371, and the water collecting body ( 371) A drainage unit 7 for discharging the water inside the water collecting body 371 to the outside may be further provided.

As shown in FIG. 3 , the washing unit 6 sprays the water stored in the water collecting body 371 to the first filtering unit 5 , so that the first filter 531 and the second filter 551 . , the third filter 571, and the heat absorbing part 41 may be provided as a means for washing at least one. The washing unit (6) is provided in the duct (3) to the injection unit (65) for supplying water to the first filtration unit (5), and water stored in the water collecting body (371) to the injection unit (65). It may be provided to include a pump 61 for moving the .

The pump 61 may be connected to the water collecting body 371 through a first connection pipe 611 , and may be connected to the injection unit 65 through a second connection pipe 613 . If the laundry treatment apparatus is provided to move the water in the water collecting body 371 to the spraying unit 65 and the draining unit 7 with only one pump 61 , the laundry treatment apparatus 100 has a flow path conversion. A part 63 may be further provided. In this case, the flow path switching unit 63 is connected to the pump 61 through the second connection pipe 613 , and the injection unit 65 is connected to the flow path switching unit ( 63), and the drain part 7 may be provided to be connected to the flow path conversion part 63 through the drain part supply pipe 633.

A valve for controlling the opening and closing of the injection part supply pipe 631 and the opening and closing of the drain part supply pipe 633 is provided in the flow path switching part 63 . Accordingly, the laundry treatment apparatus 100 may supply the water stored in the water collecting body 371 to the spraying unit 65 by controlling the valve provided in the flow path switching unit 63 , and the draining unit 7 ) can also be supplied.

The injection unit 65 shown in FIG. 3 is provided to pass through the connection duct 35, the duct through-hole 651 to which the injection unit supply pipe 631 is connected, and water supplied from the duct through-hole. A first guide 653 for guiding one filter 531, and a second guide 655 for guiding at least a portion of the water supplied through the first guide 653 toward the front surface of the heat absorbing part 41, It is shown as an example of a case provided to include. In this case, the second guide 655 may be provided as a means for allowing water to be supplied to the front surface of the heat absorbing part 41 through the first filter 531 . That is, the first filter 531 is provided to be positioned between the first guide 653 and the second guide 655 when the first filter unit 5 is fixed to the connection duct 35 , , the second guide 655 may be provided with an inclined surface inclined downward toward the first filter 531 from the upper surface of the connection duct 35 .

The first guide 653 may further include a guide through hole 654 . The guide through-hole 654 is a hole provided to pass through the first guide 653 , and the water introduced into the duct through-hole 651 passes through the guide through-hole 654 of the heat absorbing part 41 . It can be supplied to the front area. The front region of the heat absorbing part means a region positioned in a direction toward the first filter 531 based on a vertical line passing through the center of the heat absorbing part 41 .

As shown in FIG. 2 , the drain part 7 is detachably provided in the cabinet 1 to pass through a storage body 72 providing a space for storing water, and the storage body 72 . It may be provided to include an inlet 722 for introducing water discharged from the drain supply pipe 633 into the storage body 72 .

The storage body 72 may be provided as a tank in the form of a drawer drawn out from the cabinet 1 . In this case, the front panel 11 of the cabinet has a drain mounting hole into which the storage body 72 is inserted. this should be provided A panel 71 is fixed to the front surface of the storage body 72 , and the panel 71 may be provided to be detachably coupled to the drain mounting hole to form a part of the front panel 11 . .

The panel 71 may further include a groove 711 into which a user's hand is inserted. In this case, the panel 71 will also perform the function of a handle for withdrawing or inserting the storage body 72 from the cabinet.

The inlet 722 may be provided to receive water discharged from the nozzle 722a fixed to the cabinet 1 . The nozzle 722a may be fixed to the upper panel 13 of the cabinet so that it is positioned above the inlet 722 when the storage body 72 is inserted into the cabinet 1 . In this case, the drain supply pipe 633 should be provided to connect the nozzle 722a and the flow path switching unit 63 .

After the user withdraws the storage body 72 from the cabinet 1, the drain unit 7 having the above structure turns or tilts the storage body 72 toward the direction in which the inlet 722 is located. Thus, the water inside the storage body 72 can be discarded. A communication hole 721 provided to penetrate the upper surface of the storage body 72 may be further provided so that the water inside the storage body 72 is easily discharged through the inlet 722 .

As shown in FIG. 3 , it is preferable that the laundry treatment apparatus 100 includes a water level sensor 91 of a water collecting unit that measures the water level of the water collecting body 371 and transmits it to the control unit. When the water collection unit water level detection unit 91 is provided, the clothes treatment apparatus can determine when to move the water stored in the water collection body 371 to the storage body 72 , and through this, the water collection body 371 can be determined. ) of water can be prevented from flowing back into the connection duct (35).

The water level sensing unit 91 of the water collecting unit may be provided with any device as long as it can detect the water level inside the water collecting body 371, and FIG. 3 shows a plurality of electrodes of different lengths (electrical according to the water level). A sensor provided with a plurality of electrodes connected to each other is shown as an example.

In order to determine when the operation of the heat exchange unit 4 is stopped by determining the dryness of the clothes, the clothes treatment apparatus 100 may be provided with a dryness detection unit. The dryness detection unit is provided in contact with the clothes and includes an electrode sensor 95 for measuring the amount of moisture contained in the clothes, and a humidity sensor for measuring the humidity of air flowing from the drum 2 into the duct 3 . At least one of them may be provided.

The electrode sensor may be provided to include a first electrode 951 and a second electrode 953 that are fixed to the first fixed body 171 and can contact clothes inside the drum body 21 . As the dryness increases, the amount of moisture contained in the clothes will decrease (the electrical resistance of the clothes increases), so by observing the electrical resistance measured when the two electrodes 951 and 953 are connected through the clothes, the clothes treatment apparatus ( 100) can determine the dryness of the clothes. On the other hand, since the amount of moisture contained in the air flowing into the duct 3 will decrease as the drying degree of the clothes increases, the clothes treatment apparatus 100 controls the amount of air introduced into the duct 3 through the humidity sensor. It is also possible to judge the dryness of the clothes by observing the humidity.

In addition, the clothes treatment apparatus 100 may further include a temperature sensing unit 96 for measuring the temperature of the air introduced into the duct 3 . The temperature sensing unit 96 may be fixed to the upper surface of the connection duct 35 and positioned between the first filter 531 and the second filter 551 .

4 is a view showing a motor to which the noise reduction device 46 is mounted, and it can be seen that the noise reduction device 46 is mounted to surround the periphery of the impeller motor 493 of FIG. 3 . In addition to the impeller motor 493 for driving the fan 49, it is applicable to the motor 23 for rotating the drum, and it is also applicable to the compressor 45 including the motor. In addition to the motor, it is possible to implement the noise reduction device 46 in the form of surrounding the noise generating device.

The motor 493 has a generally cylindrical shape because it provides rotational force, and may be flat like the impeller motor 493 shown in FIG. 4 , or may have a longer length. The noise reduction device 46 has a shape corresponding to the shape of the noise source having a curve, such as the motor 493 . The noise reduction device 46 may have a donut shape to surround the circumference of the motor 493 .

5 is a view showing an example of the noise reduction device 46. The noise reduction device 46 includes a housing 461 including a cavity 464 with one open side and an open portion of the cavity 464. Includes a sound-absorbing plate 465 that covers the. The sound absorbing plate 465 may be disposed in contact with or toward the noise source, and a plurality of sound absorbing holes 466 are formed in the sound absorbing plate 465 .

The housing 461 is located between the first case 462 and the first case 462 and the sound-absorbing plate 465 spaced apart from the sound-absorbing plate 465 by a predetermined distance to face the sound-absorbing plate 465, and the first case 462, the sound-absorbing plate ( It consists of a second case 463 which together with 465 forms a cavity 464 . The noise reduction device 46 of this embodiment has a first case 462 and a sound-absorbing plate 465 having a cylindrical shape, and a pair of donut-shaped products forming the bottom surface of the first cylindrical case 462 and the sound-absorbing plate 465 . It is composed of two cases 463 .

The noise reduction device 46 of the present invention absorbs sound from the air inside the cavity 464 of the housing 461 and the cylindrical air layer formed by the sound-absorbing hole 466 formed in the sound-absorbing plate 465 . The noise reduction device 46 may be designed to have a resonant frequency corresponding to the frequency of the noise to be removed, thereby removing the sound.

As the sound absorption coefficient (α) is closer to 1, the sound absorption effect is excellent, and the sound absorption coefficient can be derived by the following [Equation 1].

[Formula 1]

R is a reflection coefficient, and the larger the reflection coefficient, the greater the reflected energy. The reflection coefficient can be derived by the following [Equation 2].

[Formula 2]

Z ₀ means the impedance of the incident sound (noise), and Z means the impedance of the noise reduction device 46 . When the impedance of the noise reduction device 46 matches the impedance of the noise, the reflection coefficient becomes zero. The reflection coefficient may be 0 at the resonance frequency of the noise reduction device 46, and the reflection coefficient is low for a sound near the resonance frequency, so that there is a noise reduction effect.

The impedance Z of the noise reduction device 46 can be obtained as the sum of _{the impedance Z c of the cavity 464 and the impedance Z hole} by the plurality of sound absorbing holes 466 formed in the sound absorbing plate 465 .

[Equation 3]

The impedance by the cavity 464 is determined by the depth D of the cavity 464, and can be derived from Equation (4).

[Equation 4]

The impedance by the sound absorption hole 466 can be derived from the following [Equation 5]. The porosity (Φ) means the ratio of the area sum of the sound-absorbing holes 466 therein per unit area of the sound-absorbing plate 465 and is related to the spacing between the sound-absorbing holes 466 and the radius (d) of the sound-absorbing holes 466 . The smaller the size of the porosity, the larger the thickness t of the sound absorbing plate 465, the larger the hole impedance (Zhole).

[Equation 5]

By adjusting the thickness (t) of the sound-absorbing plate 465, the radius (d) of the sound-absorbing hole 466, the spacing (p) between the sound-absorbing holes 466, and the thickness (D) of the cavity 464, the impedance of noise (Z0) ), it is possible to design the noise reduction device 46 having an impedance (Z) corresponding to the corresponding impedance (Z).

As in the embodiment shown in Figure 5, the distance between the sound absorbing plate 465 and the first case 432 is uniform and the porosity of the sound absorbing hole 466 of the sound absorbing plate 465 is constant in the case of the noise reduction device 46. has a resonant frequency. 6 is a graph showing the sound absorption coefficient and the size of the noise of the noise reduction device 46 shown in FIG. 5. As shown in (a), the sound absorption coefficient appears close to 1 at a _{specific frequency (f 0 ), (b} ), at the corresponding frequency (f ₀ ), the loudness of the sound decreases.

7 and 8 are views showing another embodiment of the noise reduction device 46 . The noise reduction device 46 shown in (a) of FIG. 7 may be configured by arranging a plurality of housings 461a to 461d having different distances from the sound absorbing plate 465 to the first case 432 in an annular shape. Since the first housing 461a to the fourth housing 461d have different depths D1 to D4 of the cavity 464, the impedances of the respective housings 461a to 461d have different values. Accordingly, the noise reduction device 46 of the present embodiment may have a plurality of resonance frequencies as shown in FIG. 7B .

The noise reduction device 46 of this embodiment may have a lower noise reduction effect in a specific frequency band than in the embodiment of FIG. 5 described above, but may remove noise of _{various frequencies f 1} to f _{4 .} When various noises are mixed, the overall noise reduction effect of the noise reduction device 46 of the present embodiment may be superior to that of the noise reduction device 46 according to the embodiment of FIG. 5 described above.

The size of each housing 461 may be configured differently in consideration of the size and direction of noise in a specific frequency band. In the case of the motor 493 rotating in the horizontal direction as an axis, the rotor of the motor 493 is biased in the lower direction due to gravity. Therefore, the noise generated from the lower part and the noise generated from the upper part may be different from each other. Considering this By disposing the housings 461 of different sizes, noise can be more efficiently removed.

Next, in Figure 8, both the sound-absorbing plate 465 and the first case 432 have a cylindrical shape, but the center is different, so the distance between the sound-absorbing plate 465 and the first case 432 may vary depending on the location. In this embodiment, since the distance between the first case 432 and the sound-absorbing plate 465, that is, the depth D of the cavity 464 is continuously changed, as shown in FIG. can be removed

The noise reduction device 46 of the present invention may be implemented according to the shape of the noise generating part, and the sound absorbing plate 465 may be formed in a curved surface corresponding to the shape of the noise source. The cavity 464 inside the housing 461 uses an empty space, so there is no need for a partition wall inside the Helmholtz resonator, so manufacturing costs are reduced and the weight is light.

In addition, as in the above-described embodiment, there is a binding that can be designed to widen the sound absorption band or to absorb the sound of various frequency bands by using the housing 461 having a different depth of the cavity 464 .

When an additional member is attached to a component to remove noise, a heat problem occurs, but in the noise canceling device of the present invention, heat may be discharged through a plurality of sound-absorbing holes 466 .

The above detailed description should not be construed as restrictive in all respects and should be considered as illustrative. The scope of the present invention should be determined by a reasonable interpretation of the appended claims, and all modifications within the equivalent scope of the present invention are included in the scope of the present invention.

100: clothes processing device 1: cabinet
111: inlet 112: door
16: lock fastening part 17: first support part
19: second support part 2: drum
21: drum body 23: motor
25: pulley 27: belt
3: duct 31: exhaust duct
33: supply duct 34: duct through hole
35: connecting duct 37: water collecting part
4: heat exchange part 41: heat absorbing part
43: heating part 45: compressor
46: noise reduction device 461: housing
462: first case 463: second case
465: sound-absorbing plate 466: sound-absorbing hole
47: pressure regulator 48: refrigerant pipe
49: fan 491: impeller
493: impeller motor 5: first filter unit
513: lock 531: first filter
551: second filter 57: first side
571: third filter 58: second side
8: second filtration unit 81: frame
83: fourth filter 6: washing unit
61: pump 63: flow path conversion unit
65: injection part 7: drainage part
71: panel 72: storage body
91: water collecting unit water level sensing unit 95: dryness sensing unit

Claims (14)

a housing having an open side and a cavity therein;
a sound-absorbing plate covering the open surface of the housing; and
It includes a plurality of sound-absorbing holes formed in the sound-absorbing plate,
The housing is
a first case facing the one surface; and
A noise reduction device including a second case positioned between the first case and the sound-absorbing plate to surround the cavity. According to claim 1,
The sound-absorbing plate noise reduction device, characterized in that it comprises a curved surface. According to claim 1,
The first case includes a cylindrical member,
The second case is located on both sides of the cylinder and is a donut-shaped plate-shaped member having an opening in the middle, and the sound-absorbing plate is a noise reduction device, characterized in that it includes a cylindrical member positioned in the opening of the second case. 4. The method of claim 3,
The distance between the first case and the sound-absorbing plate is constant and
The second case is a noise reduction device, characterized in that the width is a constant donut-shaped member. 4. The method of claim 3,
The distance between the first case and the sound-absorbing plate is different depending on the location,
The second case is a noise reduction device, characterized in that the width is a donut-shaped member different depending on the position. According to claim 1,
The housing includes a plurality of housings having different distances between the sound-absorbing plate and the first case,
The plurality of housings are noise reduction device, characterized in that disposed in an annular shape. According to claim 1,
The size of the sound-absorbing plate is noise reduction device, characterized in that smaller than the size of the first case. cabinet;
Cylindrical motor providing rotational force;
and a noise reduction device surrounding the outer peripheral surface of the motor,
The noise reduction device,
a sound-absorbing plate in contact with the outer peripheral surface of the motor and having a sound-absorbing hole;
The sound absorbing plate is coupled to one surface, the electronic device including a housing including a cavity formed therein. 9. The method of claim 8,
The housing is
a first case spaced apart from the sound-absorbing plate by a predetermined distance; and
and a second case covering between the first case and the sound absorbing plate to form the cavity. 10. The method of claim 9,
The distance between the first case and the sound-absorbing plate is constant and
and the second case is a donut-shaped member having a constant width. 10. The method of claim 9,
The distance between the first case and the sound-absorbing plate is different depending on the location,
The second case is an electronic device, characterized in that the width is a donut-shaped member different depending on the position. 10. The method of claim 9,
The housing includes a plurality of housings having different distances between the sound-absorbing plate and the first case,
The electronic device, characterized in that the plurality of housings are arranged in an annular shape. 10. The method of claim 9,
The size of the sound absorbing plate is an electronic device, characterized in that smaller than the size of the first case. 9. The method of claim 8,
The sound-absorbing plate has a cylindrical shape surrounding the outer peripheral surface of the motor,
The noise reduction device is an electronic device, characterized in that it has a donut shape surrounding the outer peripheral surface of the motor.

Images