A silencing device and an electric appliance using the same

Abstract

The utility model discloses a kind of muffler and the electric appliance applied to have the muffler, the muffler is used to set between the air inlet and power component of electric appliance, the muffler includes: passage, it is sound flow type passage, with as the first port of fluid inlet and as the second port of noise sound wave entrance, the length direction of the passage is X axis direction, the width direction of the passage is Y axis direction and the depth direction of the passage is Z axis direction, X axis, Y axis and Z axis are perpendicular to each other in pairs, the first port and second port are arranged in X axis direction with interval;And 1 / 4 wavelength pipe, it is extended to passage outside by the wall surface of passage along Y axis direction, the 1 / 4 wavelength pipe has open end and closed end, and the open end is for noise sound wave in passage to enter.

Description

Technical Field

[0001] This utility model relates to noise reduction technology, and in particular to a silencing device and an electrical appliance using the silencing device. Background Technology

[0002] As living standards continue to improve, consumers' demands for home appliances have shifted from simple functional needs to diversified quality requirements. Taking air conditioners as an example, users not only require cooling and heating functions but also seek energy efficiency, environmental friendliness, and quiet operation. Range hoods, while ensuring efficient smoke extraction, also need to operate with low noise. Gas water heaters, on the other hand, need to provide a stable supply of hot water while also boasting an aesthetically pleasing design and quiet operation. Therefore, quiet operation has become one of the core indicators for consumers evaluating the quality of home appliances, directly impacting the product's market competitiveness and user experience.

[0003] Among the noise sources of home appliances, fan noise is one of the most significant and prevalent. However, as a core functional module of home appliances, the performance of the fan directly affects key indicators such as the product's cooling and heating efficiency, operational reliability, and smoke extraction effect. Therefore, noise reduction cannot be achieved simply by reducing the fan power. Furthermore, since fan noise primarily propagates outward through air ducts, it is also impossible to reduce fan noise by isolating or closing the air ducts.

[0004] Existing noise reduction technologies for home appliances, such as the Chinese patent application number 202121746913.X, disclose a duct noise reduction device that can reduce noise propagation along the air duct. The device body includes an internal airflow duct, a sound-absorbing layer on the side wall of the airflow duct, and a protrusion protruding towards the central axis of the airflow duct, so that at least part of the air flowing through the airflow duct has a curved path due to the obstruction of the protrusion. The airflow duct is also provided with a sound-absorbing column, which divides the airflow duct at the sound-absorbing column into at least two branch channels.

[0005] However, this device is mainly designed for mid-to-high frequency noise, and its noise reduction effect is not good for low-frequency noise. Utility Model Content

[0006] The first technical problem to be solved by this utility model is to provide a noise reduction device that addresses the shortcomings of the existing technology, thereby broadening the noise reduction frequency and improving the noise reduction effect.

[0007] The second technical problem to be solved by this utility model is to provide an electrical appliance that uses the above-mentioned noise reduction device.

[0008] The technical solution adopted by this utility model to solve the first technical problem mentioned above is: a silencing device, used to be installed between the air inlet of an electrical appliance and a power component, characterized in that:

[0009] The noise reduction device includes:

[0010] The channel, being an acoustic flow channel, has a first port as a fluid inlet and a second port as a noise sound wave inlet. The length direction of the channel is denoted as the X-axis, the width direction as the Y-axis, and the depth direction as the Z-axis. The X, Y, and Z axes are mutually perpendicular. The first and second ports are arranged at intervals along the X-axis.

[0011] A quarter-wavelength tube extends outward from the wall of the channel along the Y-axis. The quarter-wavelength tube has an open end and a closed end, with the open end allowing noise sound waves from within the channel to enter.

[0012] By using a quarter-wavelength tube, the length of the tube can be controlled to effectively attenuate sound waves of a specific frequency, achieving a better noise reduction effect. In addition, the acoustic flow channel, besides serving as a noise reduction and flow guide, can also provide sufficient space for the quarter-wavelength tube to avoid it occupying too much space.

[0013] Furthermore, the quarter-wavelength tubes are of at least two, and the lengths of the at least two quarter-wavelength tubes are different along the Y-axis, thereby expanding the silencing frequency range and making it suitable for broadband noise control.

[0014] Furthermore, at least two quarter-wavelength tubes are arranged at different coordinates along the X-axis. Quarter-wavelength tubes at different coordinate positions are sensitive to noise at different frequencies, which can better reduce noise at the corresponding frequencies.

[0015] Furthermore, the 1 / 4 wavelength tubes are provided on the opposite walls of the channel along the Y-axis, thereby expanding the noise cancellation frequency range on both sides of the channel, which is suitable for broadband noise control.

[0016] Furthermore, to facilitate adaptive noise reduction matching for changes in noise sound waves under different operating conditions, a sound acquisition device, a partition, and a linear drive module are provided inside the 1 / 4 wavelength tube. The periphery of the partition is in close contact with the inner peripheral wall of the 1 / 4 wavelength tube. The linear drive module is connected between the partition and the closed end of the 1 / 4 wavelength tube. The linear drive module pushes the partition according to the noise signal acquired by the sound acquisition device to change the effective length of the 1 / 4 wavelength tube.

[0017] Furthermore, the channel is configured such that the silencing device includes a housing, and a first plate and a second plate are disposed inside the housing. The space between the first plate and the second plate constitutes the channel, and the first plate and the second plate each have openings at positions connected to the open end of a 1 / 4 wavelength tube.

[0018] Preferably, the projections of the first plate and the second plate onto the plane formed by the X-axis and Y-axis are both wavy curves.

[0019] Furthermore, the width of the second port along the Y-axis is L. On the plane projection formed by the Y-axis and Z-axis, along the X-axis, the maximum length of the first plate on the side of the second port away from the second plate is L1, the maximum length of the first plate on the side of the second port closer to the second plate is L2, the maximum length of the second plate on the side of the second port away from the first plate is L3, and the maximum length of the second plate on the side of the second port closer to the first plate is L4, satisfying the following conditions: 0.2L≤L1≤0.3L, 0.2L≤L2≤0.3L, 0.2L≤L3≤0.3L, 0.2L≤L4≤0.3L. If L1, L2, L3, and L4 are less than 0.2L, an acoustic trap cannot be formed, and noise reduction cannot be achieved. If L1, L2, L3, and L4 are greater than 0.3L, resistance will increase, affecting the airflow.

[0020] Furthermore, noise reduction holes are provided on both the first and second plates, which facilitates further absorption of noise.

[0021] To further extend the silencing frequency and improve the noise reduction effect, the silencing device also includes two third plates. One third plate is located on the side of the 1 / 4 wavelength tube away from the first plate it is connected to, while the other third plate is located on the side of the 1 / 4 wavelength tube away from the second plate it is connected to. Each third plate is spaced apart from the adjacent 1 / 4 wavelength tube. Each third plate, on the side away from the 1 / 4 wavelength tube, together with the housing, forms a cavity. An air layer is formed inside the cavity. The third plate is a perforated plate. The cavity and the third plate together form a perforated plate resonant sound absorption structure.

[0022] To further extend the silencing frequency and improve the noise reduction effect, the silencing device also includes a sound-absorbing layer, and the cavity is formed between the sound-absorbing layer and the third plate.

[0023] The technical solution adopted by this utility model to solve the second technical problem mentioned above is: an electrical appliance, characterized in that: it applies the silencing device described above.

[0024] Preferably, the appliance is a range hood, a water heater, or a refrigerator.

[0025] Preferably, the appliance is a range hood, which further includes an air inlet, a flexible hose, and a power component installed in the ceiling. The air inlet, the silencer, the flexible hose, and the power component are connected in sequence.

[0026] Compared with the prior art, the advantages of this utility model are as follows: by setting a 1 / 4 wavelength tube, the length of the 1 / 4 wavelength tube can be controlled to effectively attenuate sound waves of a specific frequency, thereby achieving a better noise reduction effect; in addition, the acoustic flow channel, in addition to playing the role of noise reduction and flow guidance, can also provide sufficient space for the setting of the 1 / 4 wavelength tube to avoid it occupying too much space. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of a range hood according to an embodiment of the present utility model;

[0028] Figure 2 This is a schematic diagram of the front cover of the concealed housing of the range hood according to an embodiment of the present utility model;

[0029] Figure 3 This is a cross-sectional front view of the silencing device according to an embodiment of the present utility model;

[0030] Figure 4 This is a partial cross-sectional view of the silencing device according to an embodiment of the present utility model;

[0031] Figure 5 This is a schematic diagram of the time-domain / frequency-domain conversion of the signal collected by the sound acquisition device inside the 1 / 4 wavelength tube of the silencing device in this embodiment of the present invention. Detailed Implementation

[0032] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0033] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Since the embodiments disclosed in this utility model can be arranged in different directions, these terms indicating direction are only for illustration and should not be regarded as limitations. For example, "upper" and "lower" are not necessarily limited to directions opposite to or consistent with the direction of gravity. In addition, features defined with "first" and "second" may explicitly or implicitly include one or more of such features.

[0034] See Figures 1-4A noise reduction device 100, typically used in electrical appliances, primarily household appliances such as range hoods, air conditioners, fresh air systems, water heaters, or refrigerators, is installed between the air inlet and the power component of the appliance. In this embodiment, it is used in a range hood, particularly a ceiling-mounted range hood. The noise reduction device 100 is located downstream of the air inlet 200 and is connected to the power component 400 within the ceiling via a flexible hose 300.

[0035] The silencing device 100 includes a housing 1 and two plates disposed within the housing 1. The plates are arranged at a relative interval, namely a first plate 21 and a second plate 22. The space between the two plates forms a channel Q. Preferably, both plates are of equal thickness. The channel Q extends between two opposite walls of the housing 1 (each plate contacts its corresponding wall of the housing 1), thus the channel Q has a first port 23 and a second port 24. The first port 23 serves as both a fluid inlet and a noise outlet, and the second port 24 serves as both a fluid outlet and a noise inlet. The housing 1 has openings at positions corresponding to the first port 23 and the second port 24. The direction in which the channel Q extends between the first port 23 and the second port 24 is the length direction of the channel Q. Figure 2 and 3 As shown in the X-axis direction, the first port 23 and the second port 24 are arranged at intervals along the X-axis, and the X-axis is perpendicular to the Y-axis and Z-axis described below. The direction in which channel Q extends between the two plates is the width direction of channel Q, i.e. Figure 2 and 3 The Y-axis direction is shown. Each plate is in the depth direction of channel Q (…). Figure 2 , 3 The direction perpendicular to the paper shown is... Figure 2 and 3 The Z-axis direction shown extends to contact the housing 1 to form a relatively enclosed channel Q. The airflow enters the first port 23 in the same direction as the length of the channel Q (perpendicular or nearly perpendicular to the first port 23), and the noise wave enters the second port 24 in the same direction as the length of the channel Q (perpendicular or nearly perpendicular to the second port 24).

[0036] The channel Q formed by the first plate 21 and the second plate 22 is a sound-flow type silencing channel. The projections of the first plate 21 and the second plate 22 onto the plane formed by the X and Y axes are both wavy curves (ignoring plate thickness), and the curvature preferably remains continuous. This channel Q serves to block the direct downward propagation of sound from the power component 400, and also acts as a guide, reducing noise without affecting airflow changes. On the horizontal plane (the plane formed by the Y and Z axes), along the X-axis direction, the first plate 21 and the second plate 22 are at least partially located outside the projection of the second port 24. Figure 2As shown in the illustration, in this embodiment, the hose 300 and the second port 24 are of equal width and have the same boundary. The leftmost projection of the first plate 21 is located to the left of the left side of the hose 300, and the rightmost projection of the second plate 22 is located to the right of the right side of the hose 300. This forms an acoustic trap, preventing sound waves from reaching the first port 23 after encountering the curved surfaces of the plates.

[0037] The width of the second port 24 is L. Projected onto the horizontal plane (the plane formed by the Y-axis and Z-axis), along the X-axis direction, the maximum length of the first plate 21 on the side of the second port 24 away from the second plate 22 is L1; the maximum length of the first plate 21 on the side of the second port 24 near the second plate 22 is L2; ​​the maximum length of the second plate 22 on the side of the second port 24 away from the first plate 21 is L3; and the maximum length of the second plate 22 on the side of the second port 24 near the first plate 21 is L4. These values ​​satisfy: 0.2L ≤ L1 ≤ 0.3L, 0.2L ≤ L2 ≤ 0.3L. If L1 and L2 are less than 0.2L, an acoustic trap cannot be formed, and noise reduction is not achieved. If L1 and L2 are greater than 0.3L, resistance will increase, affecting the airflow. Similarly, L3 and L4 also satisfy: 0.2L≤L3≤0.3L, 0.2L≤L4≤0.3L.

[0038] The first plate 21 and the second plate 22 may have the same shape and be arranged in a similar parallel manner.

[0039] Noise reduction holes 25 are provided on both the first plate 21 and the second plate 22, with a porosity of 20% to 25%, so that sound can pass through each plate.

[0040] The silencing device 100 also includes a quarter-wavelength tube 3, which is disposed on the silencing channel Q and extends outward from the wall of channel Q along the Y-axis. The end of the quarter-wavelength tube 3 connected to the wall of channel Q (first plate 21, second plate 22) is an open end 31, and the other end is a closed end 32, used to effectively attenuate sound waves of specific frequencies. The positions where each plate connects to the open end 31 of the quarter-wavelength tube 3 are also open, thus allowing sound waves in channel Q to enter the quarter-wavelength tube 3 through the open end 31. The noise reduction principle of the quarter-wavelength tube 3 is that when the length of the tube is equal to one-quarter of the sound wave wavelength, the incident sound wave and the reflected sound wave form an interference with a phase difference of 180 degrees at the open end of the tube, thereby achieving destructive interference of the sound waves and achieving a silencing effect. The length (dimension in the Y-axis direction) of the quarter-wavelength tube 3 is determined by the target silencing frequency f, calculated as L = c / 4f, where c is the speed of sound propagation in the medium. By adjusting the length and cross-sectional dimensions of the tube, efficient silencing can be achieved for sound waves of specific frequencies or frequency bands. In this embodiment, there are multiple quarter-wavelength tubes 3, with one connected to each plate. Furthermore, along the X-axis direction on the same plate, at least two quarter-wavelength tubes 3 are positioned at different X-axis coordinates. The quarter-wavelength tubes 3 are arranged in parallel, and their lengths are not identical, meaning there are at least two quarter-wavelength tubes of different lengths, thus expanding the silencing frequency range and making it suitable for broadband noise control. Specifically, in the acoustic flow type anechoic channel, quarter-wavelength tubes 3 are set at different positions on the X-axis. On the one hand, the longest length of the quarter-wavelength tube 3 is increased, which can improve the low-frequency sound absorption performance accordingly. On the other hand, the presence of quarter-wavelength tubes 3 of different lengths also has a certain sound absorption performance for the mid-frequency, because the quarter-wavelength tube 3 has higher harmonic resonance frequencies. For example, in L1 = c / 4f, f is the first-order resonance frequency, then 3f is its second-order resonance frequency, and 5f is its third-order resonance frequency. The sound absorption performance at these frequencies is also improved. Therefore, the presence of multiple quarter-wavelength tubes 3 of different lengths in the whole structure plays an important role in multi-band noise reduction.

[0041] The operating environment of a range hood is unique, and its noise is primarily influenced by the impeller speed. This impeller speed is mainly affected by factors such as the speed setting, resistance, and whether it's accelerating. Firstly, changing the speed setting changes the impeller speed. Secondly, the resistance is affected by the ceiling height and the number of users in the kitchen. Even with the same speed setting, different ceiling heights and numbers of users result in different duct resistance and thus different speeds. Finally, the impeller speed also changes during acceleration. When the speed changes, the noise frequency characteristics of the range hood change, requiring adjustment of the internal 1 / 4 wavelength tube length to achieve the best noise reduction effect.

[0042] Therefore, in environments with varying operating conditions for range hoods, this embodiment requires monitoring noise within a certain range and adjusting the effective length of the quarter-wavelength tube 3 in real time to reduce noise. A sound acquisition device 6, preferably a microphone, is installed inside the quarter-wavelength tube 3, and it can be positioned at the open end 31 of the quarter-wavelength tube 3. Furthermore, a partition 71 and a linear drive module 72 are also installed inside the quarter-wavelength tube 3. The periphery of the partition 71 is flush with the inner wall of the quarter-wavelength tube 3. The linear drive module 72 is connected between the partition 71 and the closed end 32 of the quarter-wavelength tube 3. The linear drive module 72 drives the partition 72 to move linearly along the X-axis, thereby changing the effective length of the quarter-wavelength tube 3 (the length between the open end 31 and the partition 71). The linear drive module 72 can employ any existing technology, as long as it can be installed within the quarter-wavelength tube 3. Preferably, in this embodiment, the linear drive module 72 is an electromagnet, and the extension / retraction length of the electromagnet is controlled by controlling the energization of the electromagnet. Let the initial length of the quarter-wavelength tube 3 be L0, and the target length be L. t The length that needs to change is then ΔL = L0 - L t If ΔL > 0, then the linear drive module 72 drives the partition 71 to change in the direction where the effective length of the 1 / 4 wavelength tube 3 decreases, i.e. Figure 4 The diagram shows the partition 71 moving towards the opening end 31 of the quarter-wavelength tube 3. Conversely, if ΔL < 0, the linear drive module 72 drives the partition 71 to change in the direction where the effective length of the quarter-wavelength tube 3 increases. Figure 4 The diagram shows the partition 71 moving toward the closed end 32 of the 1 / 4 wavelength tube 3.

[0043] In this embodiment, the length of the 1 / 4 wavelength tube 3 is measured as the length of the centerline in the X-axis direction.

[0044] The process from sound acquisition device 6 (microphone) to changes in the effective length of the 1 / 4 wavelength tube 3 can be achieved through the following steps: 1. Monitor whether there is a sudden change in current or speed exceeding 5% in the power board of the range hood. If not, proceed to step 2; if so, proceed to step 3. 2. The sound acquisition device 6 acquires sound data within a time interval Δt. Based on the noise characteristics, the length of the 1 / 4 wavelength tube 3 is automatically adjusted. 3. If there is a sudden change in current or speed, further determine whether the sudden change is caused by external factors or by the fan impeller undergoing a speed change, based on the noise characteristics. (The last sentence appears to be incomplete and possibly refers to a different process.) △t, collect sound data, subtract the frequency response graph of the noise from 0 to △t from the frequency response graph of △t to 2△t. If the amplitude is 0, it means that the sudden change is caused by external factors, and return to step 1. If the amplitude is not 0, it means that the impeller speed is in the variable speed stage at this time, and proceed to the next step. 4. Continue to compare the frequency response of the △t interval time, subtract the frequency response graphs of △t-2△t and 2△t-3△t. If it is 0, it means that the impeller speed is stable, and proceed to step 2. If it is still not 0, the impeller speed is still in the variable speed stage, and repeat step 3 until step 2 is reached.

[0045] The following is a detailed explanation of the length adjustment process for the 1 / 4 wavelength tube 3 in step 2. The sound acquisition device 6 (microphone) receives sound data. After FFT processing of the time-domain data, a frequency response diagram is obtained, as shown in the figure below. The length of the 1 / 4 wavelength tube 3 is then determined based on the target frequency. Specifically, along the X-axis, the 1 / 4 wavelength tube 3 at different positions exhibits different sensitivities to different frequencies. For the 1 / 4 wavelength tube 3, the closer its opening end 31 is to the inside (i.e., the more the curved surface protrudes relative to the other plate, such as...), the more sensitive it is to different frequencies. Figure 3 The position on the second plate 22 on the right side of the diagram (the position further to the left) is more sensitive to low frequencies because the length of the 1 / 4 wavelength tube 3 required for low frequencies is longer, and this position can provide sufficient space to reduce noise in the low-frequency range; correspondingly, for the 1 / 4 wavelength tube 3, the further out its opening end 31 (i.e., the more concave the curved surface is relative to the other plate, such as...) Figure 3 As shown in the diagram, the further to the right on the second plate 22 on the right, the higher the sensitivity to high frequencies. This is because the length of the 1 / 4 wavelength tube 3 required for high frequencies is short, and this position can provide enough space to reduce noise in the high-frequency band.

[0046] This allows for the proactive identification of noise characteristics to adjust the length of the quarter-wavelength tube 3, providing the advantage of actively adapting to the environment. For this patent, the quarter-wavelength tube 3 has a length limitation, with a maximum length of L. max The resonant frequency corresponding to this length is f. max =c / 4L max Therefore, the target frequencies targeted by the 1 / 4 wavelength tube 3 are all greater than f. max .

[0047] For the innermost 1 / 4 wavelength tube 3, the sound acquisition device 6 acquires the sound signal, and after FFT processing, obtains the frequency response data. For f≥f... max The frequency band, whose peak frequencies are f1, f2, f3... select f from them. min1 =min{f1, f2, f3…}, at this point, the 1 / 4 wavelength tube 3 at that position is adjusted to length L. min1 =c / 4f min1 Correspondingly, for the 1 / 4 wavelength tube 3 installed in the second part, the sound acquisition device 6 acquires the sound signal, and obtains the frequency response data after FFT processing, for f≥f max The frequency band, if f min =f1, then choose f min2 ={f2, f3…}, at this point the wavelength tube at that position is adjusted to length L min2 =c / 4f min2 And so on.

[0048] The function of the acoustic flow channel Q is to provide space for the 1 / 4 wavelength tube 3. Because when the width of the enclosure 1 is limited, if the target frequency is very low, then according to the formula L=c / 4f, the required length of the 1 / 4 wavelength tube becomes very long. If a straight channel is used instead of a curved acoustic flow channel, the width of the enclosure 1 will be insufficient, and thus it will be impossible to reduce low-frequency noise.

[0049] The silencing device 100 also includes two third plates 4. One is located on the side of the quarter-wavelength tube 3 away from the first plate 21 it is connected to, and the other is located on the side of the quarter-wavelength tube 3 away from the second plate 22 it is connected to. Each third plate 4 is spaced apart from the adjacent quarter-wavelength tube 3. On the side of the third plate 4 away from the quarter-wavelength tube 3, it forms a cavity Q1 together with the housing 1, and an air layer is formed within the cavity Q1. The third plate 3 is a perforated plate, forming a perforated plate resonant sound-absorbing structure with the cavity Q1. Since each opening has a corresponding cavity Q1 behind it, this perforated plate is a series of parallel Helmholtz resonant cavities. The principle is that when sound waves enter the cavity Q1 through the micropores of the perforated plate, they form an air column that vibrates inside. When the sound wave frequency matches the natural frequency fr of the structure, the system experiences Helmholtz resonance. The resonance frequency is determined by the following formula:

[0050]

[0051] Where c is the sound velocity, t is the thickness of the perforated plate, 0.8d is the correction coefficient at the end of the hole neck, σ is the perforation rate, and D is the back cavity depth; the resonant frequency fr can be precisely controlled by adjusting the perforation rate σ, the back cavity depth D, or the plate thickness t, targeting the noise frequency band.

[0052] The silencing device 100 also includes a sound-absorbing layer 5 disposed within the housing 1. In this embodiment, the sound-absorbing layer 5 is made of porous sound-absorbing material, such as sound-absorbing cotton, aluminum foam, or fiber felt. Through its unique pore structure and acoustic characteristics, it converts incident sound waves into heat energy, thereby significantly reducing the noise level. The cavity Q1 is sandwiched between the sound-absorbing layer 5 and the third plate 4. Its noise reduction principle is as follows: 1. Sound wave penetration: Sound waves enter the interior of the pores through the material surface and propagate in the tortuous pore channels; 2. Viscous dissipation: Sound wave vibration causes air molecules in the pores to rub against the pore walls, generating viscous resistance, and sound energy is converted into heat energy; 3. Heat conduction loss: The compression-expansion process of air in the pores triggers heat exchange, further dissipating sound energy; 4. Resonant sound absorption: Some sound waves form standing wave resonance in specific pores, enhancing the mid-to-high frequency sound absorption efficiency.

[0053] In this invention, the power component of the range hood can be intelligently voice-controlled. To this end, the range hood can be equipped with an intelligent voice control module, which includes a controller, a voice receiving module, and a voice parsing module. The voice receiving module can receive user commands, and the voice parsing module can parse the commands. Based on the parsed commands, the module can control the range hood to perform corresponding operations, thereby realizing intelligent control of the range hood and improving the user experience of using this invention.

[0054] When a sound flow control silencing device is applied to other electrical appliances, those appliances can also be intelligent control appliances.

Claims

1. A noise reduction device, used for installation between the air inlet of an electrical appliance and a power component, characterized in that: The noise reduction device includes: The channel (Q) is an acoustic flow channel, having a first port (23) as a fluid inlet and a second port (24) as a noise sound wave inlet. The length direction of the channel (Q) is denoted as the X-axis, the width direction as the Y-axis, and the depth direction as the Z-axis. The X, Y, and Z axes are mutually perpendicular. The first port (23) and the second port (24) are arranged at intervals along the X-axis. A quarter-wavelength tube (3) extends outward from the wall of the channel (Q) along the Y-axis. The quarter-wavelength tube (3) has an open end (31) and a closed end (32). The open end (31) allows noise sound waves from the channel (Q) to enter.

2. The silencing device according to claim 1, characterized in that: The 1 / 4 wavelength tube (3) has at least two, and the at least two 1 / 4 wavelength tubes (3) have different lengths along the Y-axis.

3. The silencing device according to claim 2, characterized in that: At least two 1 / 4 wavelength tubes (3) are arranged at different coordinates along the X-axis.

4. The silencing device according to claim 2, characterized in that: The 1 / 4 wavelength tube (3) is provided on the opposite walls of the channel (Q) along the Y-axis.

5. The silencer according to any one of claims 1 to 4, characterized in that: The quarter-wave tube (3) is equipped with a sound acquisition device (6), a partition (71) and a linear drive module (72). The periphery of the partition (71) is in close contact with the inner peripheral wall of the quarter-wave tube (3). The linear drive module (72) is connected between the partition (71) and the closed end (32) of the quarter-wave tube (3). The linear drive module (72) pushes the partition (71) according to the noise signal acquired by the sound acquisition device (6) to change the effective length of the quarter-wave tube (3).

6. The silencing device according to any one of claims 1 to 4, characterized in that: The silencing device includes a housing (1), in which a first plate (21) and a second plate (22) are provided. The space between the first plate (21) and the second plate (22) forms the channel (Q). The first plate (21) and the second plate (22) are each connected to the opening end (31) of the 1 / 4 wavelength tube (3).

7. The silencing device according to claim 6, characterized in that: The projections of the first plate (21) and the second plate (22) onto the plane formed by the X-axis and Y-axis are both wavy curves.

8. The silencing device according to claim 6, characterized in that: The width of the second port (24) along the Y-axis is L. On the plane projection formed by the Y-axis and Z-axis, along the X-axis, the maximum length of the first plate (21) on the side of the corresponding edge of the second port (24) away from the second plate (22) is L1, the maximum length of the first plate (21) on the side of the corresponding edge of the second port (24) close to the second plate (22) is L2, the maximum length of the second plate (22) on the side of the corresponding edge of the second port (24) away from the first plate (21) is L3, and the maximum length of the second plate (22) on the side of the corresponding edge of the second port (24) close to the first plate (21) is L4, and satisfies: 0.2L≤L1≤0.3L, 0.2L≤L2≤0.3L, 0.2L≤L3≤0.3L, 0.2L≤L4≤0.3L.

9. The silencing device according to claim 6, characterized in that: Noise reduction holes (25) are provided on both the first plate (21) and the second plate (22).

10. The silencing device according to claim 9, characterized in that: The silencing device also includes two third plates (4), one of which is located on the side of the 1 / 4 wavelength tube (3) away from the first plate (21) to which it is connected, and the other third plate (4) is located on the side of the 1 / 4 wavelength tube (3) away from the second plate (22) to which it is connected. Each third plate (4) is spaced apart from the adjacent 1 / 4 wavelength tube (3). Each third plate (4) together with the housing (1) on the side away from the 1 / 4 wavelength tube (3) forms a cavity (Q1). An air layer is formed in the cavity (Q1). The third plate (4) is a perforated plate. The cavity (Q1) and the third plate (4) form a perforated plate resonant sound absorption structure.

11. The silencing device according to claim 10, characterized in that: The silencing device further includes a sound-absorbing layer (5), and the cavity (Q1) is formed between the sound-absorbing layer (5) and the third plate (4).

12. An electrical appliance, characterized in that: The application uses a silencing device as described in any one of claims 1 to 11.

13. The electrical appliance according to claim 12, characterized in that: The appliance is a range hood, water heater, or refrigerator.

14. The electrical appliance according to claim 13, characterized in that: The appliance is a range hood, which also includes an air inlet (200), a hose (300), and a power component (400) installed in the ceiling. The air inlet (200), the silencer, the hose (300), and the power component (400) are connected in sequence.

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