Active noise reduction system mounting structure of lampblack suction device and range hood

Abstract

The utility model relates to an active noise reduction system installation structure of a cooking fume suction device and a range hood, an active noise reduction system comprises a plurality of sound collection devices for collecting sound signals, a loudspeaker and a controller, an air duct comprises a first wall and a second wall which are oppositely arranged, and the first wall and the second wall are arranged in parallel. The inner sides of the main body of the first wall and the main body of the second wall are both provided with the sound acquisition devices, and at least one placement part for arranging the sound acquisition devices is further arranged at the position, closer to the center of the air duct relative to the main body of the first wall and the main body of the second wall, in the air duct; each sound collection device comprises a shell and a sound collection element arranged in the shell, and the shell is further provided with a sound transmission channel for transmitting sound in the air channel to the position where the sound collection element is located. The active noise reduction system installation structure can achieve the purposes of oil prevention and wind prevention, and then the accuracy of sound collection is guaranteed.

Description

Technical Field

[0001] The utility model relates to the technical field of range hoods, in particular to an installation structure of an active noise reduction system of a range hood device and a range hood. Background Art

[0002] A range hood is a kitchen appliance that purifies the kitchen environment. Range hood noise has always been one of the main problems that bothers users. Active noise reduction, as a new type of noise reduction technology, is also being considered for use in range hoods to reduce noise. An active noise reduction device usually includes a microphone and a speaker. The microphone collects the noise generated when the range hood is working, and the collected noise sound waves are transmitted to the controller in the form of electrical signals. After analysis and processing, the controller sends instructions to the speaker to control the speaker to emit sound waves that match the noise sound waves to neutralize the noise sound waves, thereby achieving the effect of noise reduction. For example, the Chinese invention patent application with application number CN202010935185.0 (application publication number: CN111928310A) discloses a range hood with active noise reduction function. The microphone of the range hood is arranged in the casing and is distributed around the fan in an array, and the speaker assembly is distributed below the fan. However, the range hood in this patent application simply employs an array arrangement around the fan, involving a large number of microphone components. The application fails to comprehensively consider factors such as the location of the noise source, the air duct structure, and the airflow characteristics to rationally arrange the number and position of the microphones to obtain more comprehensive sound field information. Generally speaking, microphones also require corresponding protective structures. If a large number of microphones and protective structures are arranged, they will significantly squeeze the space within the air duct, significantly affecting the air volume of the range hood and the smooth installation of key components such as the fan.

[0003] In order to ensure the noise reduction effect, all microphones and speakers used in the active noise reduction system of the range hood in the existing technology are often arranged in the internal air duct of the range hood. However, due to the oily environment of the range hood, the microphones and speakers are often contaminated, resulting in the active noise reduction system causing the noise reduction effect to decrease as the use time increases, and even causing malfunction. To this end, Chinese utility model patent application number CN201820250745.7 discloses an active noise reduction device for a range hood with an oil prevention device, comprising an input device, a central data processor, and a noise reduction unit. The input device includes a microphone, which is arbitrarily installed at any location on the range hood. The noise reduction unit includes at least two noise reduction boxes, which are located at the bottom of the range hood's volute, facing the air inlet. An oil prevention device is located below the noise reduction box, which is also located at the bottom of the volute and covers the noise reduction box. The oil prevention device includes a porous sound-transmitting shell and an oil-proof and sound-transmitting film attached to the surface of the porous sound-transmitting shell. At least one noise reduction speaker is located in the noise reduction box. Both the microphone and the noise reduction speaker are connected to the central data processor. The central data processor loads a noise reduction device self-test module and an oil pollution detection module. The oil pollution detection module detects oil pollution damage to the oil prevention device. The self-test module receives and processes the system signal reported by the device to determine whether the microphone and the noise reduction speaker have been added. At the same time, a timing detection module is provided in the self-test module. However, the oil-proof device of the active noise reduction device of this patent application still has certain shortcomings. The oil-proof device achieves sound transmission and oil prevention through a porous sound-permeable shell and an oil-proof film attached to the surface of the porous sound-permeable shell. The influence of wind noise in the air duct of the range hood is not taken into consideration, that is, no effective wind noise prevention treatment is performed. On the other hand, if the porous sound-permeable shell set up above has a large number of openings, it will have an adverse effect on oil prevention and wind prevention. If the number of openings is small, the noise will be lost more during the propagation process, resulting in the accuracy of sound collection being affected. Utility Model Content

[0004] The first technical problem to be solved by the present invention is to provide an installation structure of an active noise reduction system for a range fumes extraction device in which the number of sound collection devices is reasonably arranged and which can achieve more comprehensive collection of target noise, in response to the current status of the existing technology.

[0005] The second technical problem to be solved by the present invention is to provide an installation structure of an active noise reduction system of a range hood device, which can achieve the purpose of oil and wind protection and thus ensure the accuracy of sound collection, in response to the current status of the existing technology.

[0006] The third technical problem to be solved by the present invention is to provide a range hood using the above-mentioned active noise reduction system installation structure in response to the current status of the existing technology.

[0007] The technical solutions adopted by the present invention to solve the first and second technical problems are: an installation structure of an active noise reduction system for a range hood, the active noise reduction system comprising a sound collection device, a speaker and a controller, the controller receiving a noise signal from the sound collection device and generating a noise reduction signal, which is then transmitted to the speaker to emit a noise reduction wave, the sound collection device and the speaker being arranged in the air duct of the range hood, the sound collection device and the speaker being provided in a plurality of ways, the air duct comprising a first wall and a second wall arranged opposite to each other, the sound collection devices being provided on the inner sides of the main bodies of the first wall and the second wall, at least one placement portion for providing a sound collection device being provided in the air duct at a position closer to the center of the air duct than the main bodies of the first wall and the second wall, each sound collection device comprising a sound collection element provided in a shell and in the shell, the shell further comprising a sound propagation channel for transmitting sound in the air duct to the position where the sound collection element is located.

[0008] The above-mentioned "oil fume suction device" is a device or appliance that can absorb and exhaust oil fume, such as a range hood, or other kitchen appliances with oil fume suction function, such as an integrated stove.

[0009] The above-mentioned "air duct" is understood to be any section of the flow path from the air inlet of the smoke hood of the self-priming oil fume device to the location of the fan system. For example, it can refer to the inner cavity space of the smoke hood, or it can refer to the channel structure between the fan system and the air outlet of the smoke hood, or it can refer to the space inside the fan rack where the fan system is located.

[0010] As a preferred solution, in order to form the above-mentioned placement portion and reduce the adverse effects of the placement portion on the stability of the airflow in the air duct, the main body of the second wall has a strip-shaped boss protruding toward the air duct and arranged along the extension direction of the air duct, and at least one sound collection device is provided on the strip-shaped boss, and the strip-shaped boss constitutes the above-mentioned placement portion.

[0011] Taking into account the arrangement of the centrifugal fan in the air duct and the air flow at the air inlet of the centrifugal fan, in order to more comprehensively collect the noise there, at least two sound collection devices are provided on the main body of the second wall, located on the left and right sides of the strip-shaped boss, and the setting position is higher than the height position of the sound collection device provided on the strip-shaped boss.

[0012] Taking into account that the main source of target noise in the air duct is the centrifugal fan, especially the aerodynamic noise generated during the operation of the impeller in the centrifugal fan, which is basically transmitted through the main air inlet and auxiliary air inlet of the centrifugal fan, in order to adapt to this, an air outlet plate is also provided in the air duct, on which an air outlet is opened. The air outlet is opened close to the first wall of the air duct, and the number of sound collection devices on the second wall is greater than the number of sound collection devices on the first wall.

[0013] The sound collecting device includes a shell arranged on the first wall of the air duct and a sound collecting element arranged in the shell. The shell also has a sound collecting channel for transmitting the sound in the air duct to the position where the sound collecting element is located.

[0014] The housing may be designed as an integral structure, such as an integral curved pipe structure. However, in order to facilitate the installation of components such as the sound collecting element, the housing is preferably designed as a split structure assembled together using fasteners. Specifically, the housing includes:

[0015] A mounting frame having a receiving slot formed thereon, wherein the sound collecting element is disposed in the receiving slot;

[0016] a windshield disposed outside the mounting frame and defining a sound collection channel arranged along the extension direction of the air duct and connected to the receiving groove between the windshield and the mounting frame; and a second sound inlet, connected to the sound collection channel and allowing sound in the air duct to enter the sound collection channel, is defined between a leeward end of the windshield and the mounting frame along the direction of airflow in the air duct.

[0017] The above-mentioned receiving groove and sound collection channel together constitute the sound propagation channel.

[0018] The above-mentioned “end portion of the wind shield facing leeward” may be understood as: an end of the wind shield adjacent to the fan system of the range hood along the extension direction of the air duct.

[0019] The above-mentioned "sound collection channel is arranged along the extension direction of the air duct" can be understood as the overall extension direction of the sound collection channel being consistent with or parallel to the extension direction of the air duct, or it can be understood as the overall extension direction of the sound collection channel having a slightly certain inclination angle relative to the extension direction of the air duct (such as an inclination angle range of 0 to 30 degrees).

[0020] The provision of a windshield on the sound collection device effectively isolates the sound collection element from interference with the airflow in the duct and prevents contamination of the sound collection element by oil in the airflow. Placing the sound collection channel along the extension direction of the duct facilitates direct reception of noise within the duct by the sound collection element. Furthermore, given the need for a sound collection channel of sufficient length along the sound propagation path to protect against wind noise and reduce the impact of duct airflow on sound collection, arranging the sound collection channel along the extension direction of the duct allows the entire sound collection device to be smaller in the direction perpendicular to the duct extension, effectively occupying less space within the range hood's duct. This, in turn, reduces wind resistance at the location of the sound collection device within the duct, thereby preventing any impact on the stability of the airflow within the duct and, to a certain extent, reducing wind noise.

[0021] As an improvement, the opening direction of the second sound inlet is consistent with the extension direction of the air duct, thereby enabling the second sound inlet of the sound collection channel to face the sound source so as to directly receive the noise in the air duct.

[0022] In order to further reduce the possibility of the sound collecting element being contaminated by oil, the receiving groove has a first sound inlet for the sound in the sound collecting channel to enter the receiving groove, and the opening direction of the first sound inlet is arranged at an angle to the extension direction of the sound collecting channel.

[0023] As an improvement, the opening direction of the first sound inlet is perpendicular to the extension direction of the sound collection channel. By arranging the opening direction of the first sound inlet of the receiving tank perpendicular to the extension direction of the sound collection channel, the entire path of noise in the air duct from the second sound inlet into the sound collection channel and then propagating to the location of the sound collection element in the receiving tank is a curved path. This curved path prevents excessive oil from directly passing through the sound collection channel and coming into contact with the sound collection element. Instead, it causes most of the oil to adhere to the side walls of the sound collection channel, thereby keeping the sound collection element as far away from the oil as possible and extending its service life. Furthermore, the curved path design of the sound propagation path within the sound collection device attenuates high-frequency sounds (such as the high-frequency sound portion of wind noise and non-target noise such as high-frequency sound components generated by the fan system) while having a minimal impact on low-frequency sounds. Therefore, it is well suited for propagating low-frequency noise within the sound collection device, facilitating accurate collection of low-frequency noise by the sound collection element. The second sound inlet is set upward, so that the noise in the air duct can smoothly enter the sound collection channel from top to bottom through the second sound inlet, avoiding the loss of sound pressure due to too many turns in the sound propagation path, and ensuring the accuracy of sound collection.

[0024] Taking into account that the air duct of the range hood is mostly extended vertically, in order to adapt to this, the sound collection channel is extended vertically.

[0025] In order to further improve the oil-proof effect, an oil-proof sound-permeable membrane is also provided at the first sound entrance.

[0026] As an improvement, the sound collection channel is also equipped with a windproof and sound-permeable member made of a porous material. Using a damping material such as a porous sound-absorbing material as a windproof and sound-permeable member can slow down airflow, eliminate airflow impact, and ensure that the collected sound is transparent. Specifically, polyurethane foam, melamine foam, or other materials can be used for the windproof and sound-permeable member. This windproof and sound-permeable member prevents airflow from impacting the oil-proof sound-permeable membrane and generating additional noise. Furthermore, the porous nature of the material absorbs high-frequency components of sound energy, thereby filtering out noise signals.

[0027] In order to ensure the active noise reduction effect of the active noise reduction system, along the sound propagation direction in the air duct, the position of the loudspeaker is located downstream of the position of the sound collecting element.

[0028] The technical solution adopted by the present invention to solve the third technical problem is: a range hood, including an air duct and an active noise reduction system, wherein the active noise reduction system adopts the active noise reduction system mounting structure of the above-mentioned range hood device and is arranged on the air duct.

[0029] As an improvement, the range hood includes a casing, and the internal space of the casing defines the air duct.

[0030] Compared with existing technologies, the present invention offers the following advantages: multiple sound collection devices within the air duct are not only arranged on the opposing first and second walls within the duct, but also in the area between the first and second walls. This allows for more comprehensive collection of target noise from different directions. Furthermore, the sound collection elements of the sound collection devices are housed within the housing, reducing oil contamination and the influence of wind noise within the duct, thereby improving the accuracy of target noise collection. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic diagram of the three-dimensional structure of the installation structure of the active noise reduction system of the range fumes extraction device according to an embodiment of the present utility model;

[0032] Figure 2 This is a sectional perspective view of the installation structure of the active noise reduction system of the range fumes extraction device according to an embodiment of the present invention;

[0033] Figure 3 This is a schematic diagram of the three-dimensional structure of the sound collection device according to an embodiment of the utility model;

[0034] Figure 4 This is an exploded view of the sound collection device according to an embodiment of the present utility model;

[0035] Figure 5 A vertical sectional perspective view of a sound collection device according to an embodiment of the present invention;

[0036] Figure 6 for Figure 5 The schematic diagram of the structure after omitting the windproof and sound-permeable parts. DETAILED DESCRIPTION

[0037] The present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

[0038] In the specification and claims of the present invention, directional terms such as "front," "back," "up," "down," "left," "right," "side," "top," and "bottom" are used to describe various exemplary structural parts and components of the present invention. However, these terms are used herein for convenience of description only and are based on the exemplary orientations shown in the accompanying drawings. Since the embodiments disclosed in the present invention can be arranged in different orientations, these directional terms are intended for illustrative purposes only and should not be construed as limiting. For example, "up" and "down" are not necessarily limited to directions opposite to or consistent with the direction of gravity.

[0039] Figures 1-6 The present invention shows an installation structure of the active noise reduction system of the range hood and a preferred embodiment of the range hood. The range hood is a device or appliance that can absorb and exhaust oil fumes. It can refer to a range hood, or it can refer to other kitchen appliances with oil fume extraction function, such as an integrated stove. Taking the range hood as an example, the active noise reduction system of the range hood is usually arranged in the air duct of the range hood. The above-mentioned "air duct" can refer to the casing of the range hood, or it can refer to a box structure with a "channel" for oil fumes to pass through separately, such as the channel between the fan system and the smoke hood of the range hood in a ceiling-mounted range hood. The active noise reduction system generally includes a sound collection device, a speaker and a controller. The sound collection device includes a shell 2 and a sound collection element 11 (generally a microphone) arranged in the shell 2. The microphone collects the noise generated by the range hood during operation and transmits the collected noise waves to the controller in the form of electrical signals. The controller analyzes and processes the noise and issues instructions to the speaker, controlling it to emit sound waves that match the noise waves to neutralize the noise waves, thereby achieving a noise reduction effect. The sound collection device for the active noise reduction system of the range hood of this embodiment can be used to install the sound collection element 11 and provide oil and wind protection.

[0040] The range hood includes a housing and a fan system, which is housed within the housing. The passage within the housing is the air duct 10 of this embodiment. The air duct (i.e., the housing) of this embodiment extends vertically and comprises a front sidewall 101 (i.e., a first wall) and a rear sidewall 102 (i.e., a second wall) that oppose each other in the front-to-back direction, as well as a left sidewall 103 and a right sidewall 104 that oppose each other in the left-to-right direction. Sound collection devices (for accommodating microphones) can be installed on both the front sidewall 101 and the rear sidewall 102 of the air duct 10. Furthermore, to accommodate the installation of a centrifugal fan within the air duct, an air outlet plate 105 is provided at the top of the air duct 10. This air outlet plate 105 defines an air outlet 1050, with the air outlet 1050 located near the front sidewall 101 of the air duct 10. At least two sound collection devices can be installed sequentially along the left-to-right direction on the rear sidewall 102 of the air duct. For example, three sound collection devices are arranged on the rear sidewall of the air duct 10. Specifically, the rear side wall 102 of the air duct has a strip-shaped boss 1020 protruding into the air duct and arranged along the extension direction of the air duct. At least one sound collection device is arranged on the strip-shaped boss 1020. The strip-shaped boss 1020 constitutes the placement portion of the air duct for the sound collection device. The other sound collection devices arranged on the rear side wall 102 are arranged on the left and right sides of the strip-shaped boss 1020, and are arranged at a height higher than the sound collection devices arranged on the strip-shaped boss 1020. Figure 2 The figure shows that a sound collecting device is provided on the main body of the rear side wall 102, corresponding to the area on the left and right sides of the strip boss 1020. Since the air outlet 1050 is close to the front side wall 101 of the air duct 10, it should be ensured that a corresponding sound collecting device is also provided on the front side wall 101 of the air duct 10. Figure 1 It is shown that a sound collecting device is provided on the front side wall 101 of the air duct 10 .

[0041] Speakers 60 are also located on the left and right walls 103, 104 of the air duct 10. Given that the propagation direction of the noise to be collected within the air duct 10 is substantially opposite to the direction of airflow within the duct 10, to enhance the active noise reduction effect, the speakers 60 are positioned at a lower elevation than the microphone (sound collection device). The sound output of the speakers 60 is directed downward, meaning that the speakers 60 are located upstream of the microphone (sound collection device) along the direction of airflow within the duct 10. Of course, it is also possible to place the microphone and its sound collection device in the middle of the air duct 10 (e.g., by installing a bracket), but this would require addressing the impact on airflow and susceptibility to oil contamination.

[0042] The sound collecting device comprises a housing 2, an oil-proof sound-permeable membrane 28 and a wind-proof sound-permeable member 30. The housing 2 comprises a mounting frame 20 and a windproof cover 40.

[0043] The mounting bracket 20 can be mounted on the rear sidewall of the air duct 10. Its front sidewall is provided with a receiving slot 21 for accommodating the sound collecting element 11. The front portion of this receiving slot 21 has an opening serving as a first sound inlet 211 for sound to enter the receiving slot 21. This first sound inlet 211 should be understood as an opening that allows sound from the outside (in this embodiment, the sound collection channel) to enter the receiving slot 21 and be effectively collected by the sound collecting element. When the mounting bracket 20 is properly installed on the rear sidewall of the air duct 10, the rear wall of the mounting bracket 20, where the receiving slot 21 is located, abuts against the rear sidewall of the air duct 10.

[0044] The mounting frame 20 also has third mounting portions 263 extending to the left and right, respectively, to expose the exterior of the wind shield 40. A fourth mounting portion 264 extending downward from the bottom of the mounting frame 20 to expose the exterior of the wind shield 40 is also provided. Both the third mounting portion 263 and the fourth mounting portion 264 are screwed to the sidewalls of the air duct 10. The lower area of the receiving slot 21 of the mounting frame 20 has forward-extending connecting posts 265, to which the wind shield 40 is connected via screws 50.

[0045] The wind shield 40 includes a first side wall 411 and a second side wall 412 that are arranged opposite to each other and spaced apart, and a third side wall 413 that is connected between the front edge of the first side wall 411 and the front edge of the second side wall 412, thereby forming a cover structure with an open rear side. The third side wall 413 of the wind shield 40 is located in front of the receiving slot 21 of the mounting bracket 20. The third side wall 413 of the wind shield 40 has a shape that is arranged along the direction of airflow in the air duct 10 (such as Figure 2The guide surface 4130 (in the direction indicated by the hollow arrow) gradually tilts toward the interior of the air duct 10. Specifically, the guide surface 4130 is located at the lower portion of the third side wall 413, that is, at the end of the third side wall 413 that faces the wind. It tilts forward from bottom to top, while the upper portion of the third side wall 413 extends substantially vertically and is opposite to the portion of the mounting bracket 20 where the receiving slot 21 is located in the front-to-back direction. Along the direction of airflow within the air duct 10, the guide surface 4130 of the wind shield 40 is located upstream of the receiving slot 21 of the mounting bracket 20. Positioning the guide surface 4130 of the wind shield 40 downward also allows sufficient space within the wind shield 40, opposite the front portion of the receiving slot 21, to accommodate components such as the windproof and sound-permeable member 30 and the oil-proof and sound-permeable membrane 28. In addition, considering that the inclination angle of the guide surface 4130 toward the air duct 10 is too large, it will also affect the flow of air in the air duct 10 to a certain extent, such as affecting the amount of air flowing in the air duct 10 or generating additional noise problems. For this reason, the inclination angle of the guide surface 4130 of the wind shield 40 needs to be reasonably designed. The angle formed between the guide surface 4130 of the above-mentioned wind shield 40 and the side wall of the air duct 10 for installing the wind shield 40 is recorded as A, and the value range of A is: A≤60°.

[0046] In order to improve the oil-proof effect, the windshield 40 of this embodiment can be made of plastic or metal.

[0047] In this embodiment, the windshield 40 and the front side of the mounting frame 20 form a vertically extending gap in the front-to-back direction. This gap is open at its upper end (i.e., the end closest to the noise source) and closed at its lower end (i.e., the end further from the noise source). Located in front of the receiving slot 21 of the mounting frame 20, this gap serves as the sound collection channel 200, extending in the same direction as the air duct 10. More specifically, a second sound inlet 45, communicating with the sound collection channel 200, is defined between the leeward end of the windshield 40 (i.e., the portion of the range hood's fan system along the air duct's direction of extension) and the front sidewall of the mounting frame 20. This second sound inlet 45 faces upward, substantially aligning with the direction of extension of the air duct 10. The air duct 10 in this embodiment also extends vertically, meaning that the sound collection channel 200 extends in the same direction B2 as the air duct 10. The opening direction B1 of the first sound inlet 211 is substantially perpendicular to the extending direction B3 of the sound collecting channel 200 .

[0048] The lower section of the sound collection channel 200 is aligned with the first sound inlet 211 at the front of the receiving slot 21 of the mounting bracket 20 in the front-to-back direction. The windscreen 40 effectively prevents high-speed oil smoke airflow from directly impacting the windproof and sound-permeable member 30, significantly reducing oil smoke contamination of the member. Furthermore, when the windscreen 40 is coupled with the mounting bracket 20, only the upper second sound inlet 45 remains, directly isolating noise from the lower airflow and secondary turbulence. This ensures that noise entering the windproof and sound-permeable member 30 primarily originates from above, in the direction of the range hood's primary noise source, thus ensuring accurate noise collection.

[0049] Since the sound collecting element 11 is installed in the receiving groove 21 of the mounting frame 20 and a windshield 40 is provided outside the mounting frame 20, the interference of the airflow in the air duct 10 on the sound collecting element 11 can be effectively isolated, and the oil in the airflow can be prevented from contaminating the sound collecting element 11. At the same time, a windproof and sound-permeable member 30 is provided in the sound collecting channel formed between the mounting frame 20 and the windshield 40, which can effectively reduce the influence of wind noise. Even if a small amount of airflow enters the sound collecting channel 200, the pressure pulsation can be weakened in the windproof and sound-permeable member 30, thereby reducing the influence on the accuracy of the microphone sound collection. Furthermore, considering that the noise in the air duct 10 (mainly originating from the fan system) propagates along the extension direction of the air duct 10 and the propagation direction is opposite to the direction of the airflow in the air duct 10, the sound collection channel 200 is arranged along the extension direction of the air duct so that the second sound inlet 45 of the sound collection channel 200 faces the sound source so as to directly receive the noise. Furthermore, considering that a windproof and sound-permeable member 30 of sufficient length needs to be provided along the sound propagation path to prevent wind noise, thereby reducing the impact of the airflow in the air duct 10 on sound collection, the present embodiment arranges the sound collection channel 200 for accommodating the windproof and sound-permeable member 30 in the extension direction of the air duct 10. This allows the entire sound collection device to be made smaller in the dimension perpendicular to the extension direction of the air duct, i.e., it occupies less space in the air duct 10 of the range hood, thereby reducing the wind resistance at the location of the sound collection device in the air duct 10. Therefore, the stability of the airflow in the air duct 10 is not affected, and the generation of wind noise is also reduced to a certain extent. On this basis, considering that the range hood air duct environment is filled with oil, if the opening direction B1 of the first sound inlet 211 is aligned with the extension direction B3 of the sound collection channel 200, the sound collection element 11 is easily contaminated by the oil flowing down the air duct 10. Therefore, in this embodiment, the opening direction B1 of the first sound inlet 211 of the receiving tank 21 is arranged perpendicular to the extension direction B3 of the sound collection channel 200. This creates a curved path for the noise in the air duct 10, from the second sound inlet 45 entering the sound collection channel 200 and then propagating to the location of the sound collection element 11 in the receiving tank 21. This curved path prevents excessive oil from directly passing through the sound collection channel 200 and coming into contact with the sound collection element 11. Instead, most of the oil adheres to the sidewalls of the sound collection channel 200 or the windproof and sound-permeable member 30, thereby keeping the sound collection element 11 as far away from the oil as possible and extending the service life of the sound collection element 11.Furthermore, considering that the target noise (primarily from the fan system) that the active noise reduction system needs to collect is low-frequency noise, the sound propagation path within the sound collection device adopts a curved path design. This path attenuates high-frequency sounds (such as the high-frequency sound portion of wind noise and non-target noise such as the high-frequency sound components generated by the fan system) while having less impact on low-frequency sounds. Therefore, it is well suited to the propagation of low-frequency noise within the sound collection device, facilitating accurate collection of low-frequency noise by the sound collection element 11. This is primarily due to the longer wavelength of low-frequency noise, which can better adapt to the bends and irregular shapes of the pipe. When low-frequency noise propagates in a curved pipe, due to its longer wavelength, it is less likely to be obstructed or reflected by the pipe, and thus can be better propagated and diffused. High-frequency noise, on the other hand, has a shorter wavelength and is easily reflected and absorbed by the shape and curvature of the pipe, making it more difficult for it to propagate and diffuse within the pipe than low-frequency noise.

[0050] The oil-proof sound-permeable membrane 28 covers the first sound inlet 211 of the receiving slot 21 of the mounting frame 20, specifically at the edge of the front opening of the receiving slot 21 of the mounting frame 20. More specifically, to facilitate installation of the oil-proof sound-permeable membrane 28 and ensure a tight seal after installation, the receiving slot 211 is formed with an annular step 210 at the edge of the first sound inlet 211. The oil-proof sound-permeable membrane 28 is positioned on this annular step 210. To ensure the oil-proof performance of the oil-proof sound-permeable membrane 28 while ensuring effective sound wave transmission, the oil-proof sound-permeable membrane 28 in this embodiment is preferably a polyethylene film. A fourth distance, denoted as f, is defined between the oil-proof sound-permeable membrane 28 and the sound collecting element 11. The value of f is within the range of f ≥ 2 mm. This prevents contact between the membrane 28 and the sound collecting element 11 due to vibration or micro-deformation, which could cause variations in sound transmission and affect sound collection accuracy. It should be understood that the fourth distance f between the oil-proof sound-permeable membrane 28 and the sound collecting element 11 should refer to the distance between the oil-proof sound-permeable membrane 28 and the microphone chip on the sound collecting element 11. This means that the oil-proof sound-permeable membrane 28 may partially contact other components of the circuit board (such as solder joints or fixing screws) on which the microphone chip resides. The windproof sound-permeable member 30 does not directly contact the oil-proof sound-permeable membrane 28 to ensure oil-proofing. Specifically, a sixth distance is defined between the oil-proof sound-permeable membrane 28 and the main body of the windproof sound-permeable member 30 in the front-to-back direction. To prevent contact between the oil-proof sound-permeable membrane 28 and the windproof sound-permeable member 30, which could affect sound transmission, the sixth distance should be greater than 0.1 mm, preferably ranging from 0.5 mm to 3 mm.

[0051] To effectively slow airflow and eliminate airflow impact, the windproof, sound-permeable member 30 is made of a porous, sound-absorbing material. For example, polyurethane foam or melamine foam can be used, and the porosity of the windproof, sound-permeable member 30 is greater than 70%. The windproof, sound-permeable member 30 of this embodiment not only prevents airflow from impacting the oil-proof sound-permeable membrane 28 and generating additional noise, but also, due to its porous nature, absorbs high-frequency components of sound energy, thereby filtering out noise signals. More specifically, the front sidewall of the windproof, sound-permeable member 30 abuts against the rear sidewall of the third sidewall 413 of the windshield 40, compressing the windproof, sound-permeable member 30. This compression increases the material density, effectively reducing the possibility of airflow pressure pulsations penetrating the windproof membrane 28, thereby further enhancing the windproof effect.

[0052] The sound collecting element 11 of this embodiment is disposed within the sound collecting device to reduce oil contamination and the effects of wind noise within the air duct. In particular, the sound collecting element 11 is disposed near the same side wall of the air duct 10 as the air outlet 1050 on the air outlet plate 105. As a result, after passing through the sound collecting device, the airflow within the air duct 10 can be smoothly discharged outward through the air outlet of the air outlet plate, thereby preventing airflow disturbances. This prevents pressure fluctuations caused by airflow changes from overlapping the target noise pressure and affecting the accuracy of sound collection by the sound collecting element 11.

[0053] This embodiment also relates to a range hood, comprising an air duct 10 for smoke to pass through and an active noise reduction system provided in the air duct 10, wherein the active noise reduction system comprises the above-mentioned sound collection device.

Claims

1. An installation structure for an active noise reduction system of a range fumes extraction device, the active noise reduction system comprising a sound collection device, a speaker (60), and a controller, the controller receiving a noise signal from the sound collection device and generating a noise reduction signal, which is then transmitted to the speaker (60) to emit a noise reduction wave, the sound collection device and the speaker (60) being both arranged in an air duct (10) of the range fumes extraction device, characterized in that: There are a plurality of sound collecting devices. The air duct (10) comprises a first wall (101) and a second wall (102) arranged opposite to each other. The sound collecting devices are provided on the inner sides of the main body of the first wall (101) and the main body of the second wall (102). At least one placement portion for arranging the sound collecting device is provided in the air duct (10) at a position closer to the center of the air duct (10) than the main body of the first wall (101) and the main body of the second wall (102). Each of the sound collecting devices comprises a sound collecting element (11) provided in a shell (2) and provided in the shell (2). The shell (2) further comprises a sound propagation channel for transmitting the sound in the air duct (10) to the position where the sound collecting element (11) is located.

2. The active noise reduction system installation structure of the range fumes extraction device according to claim 1, characterized in that: The main body of the second wall (102) is provided with a strip-shaped boss (1020) protruding toward the inside of the air duct (10) and arranged along the extension direction of the air duct. At least one sound collecting device is arranged on the strip-shaped boss (1020), and the strip-shaped boss (1020) constitutes the placement portion.

3. The active noise reduction system installation structure of the range fumes extraction device according to claim 2, characterized in that: There are at least two sound collecting devices arranged on the main body of the second wall (102) located on the left and right sides of the strip-shaped boss (1020), and the height of the sound collecting devices arranged on the strip-shaped boss (1020) is higher than that of the sound collecting devices arranged on the strip-shaped boss (1020).

4. The active noise reduction system installation structure of the range fumes extraction device according to claim 3, characterized in that: An air outlet plate (105) is further provided in the air duct (10), and an air outlet (1050) is provided on the air outlet plate (105). The air outlet (1050) is provided near the first wall (101) of the air duct (10), and the number of sound collection devices on the second wall (102) is greater than the number of sound collection devices on the first wall (101).

5. The active noise reduction system installation structure of the range fumes extraction device according to any one of claims 1 to 4, characterized in that The housing (2) comprises: A mounting frame (20) is provided with a receiving groove (21), wherein the sound collecting element (11) is placed in the receiving groove (21); A windshield (40) is provided outside the mounting frame (20) and defines a sound collection channel (200) arranged along the extension direction of the air duct (10) and connected to the receiving groove (21) between the windshield (40) and the mounting frame (20); along the direction of airflow in the air duct (10), a second sound inlet (45) is defined between the leeward end of the windshield (40) and the mounting frame (20) and connected to the sound collection channel (200) for allowing sound in the air duct (10) to enter the sound collection channel (200); The aforementioned receiving groove (21) and the sound collecting channel (200) together constitute the sound propagation channel.

6. The active noise reduction system installation structure of the range fumes extraction device according to claim 5, characterized in that: The opening direction of the second sound inlet (45) is consistent with the extension direction of the air duct (10).

7. The active noise reduction system installation structure of the range fumes extraction device according to claim 5, characterized in that: The receiving groove (21) has a first sound inlet (211) for the sound in the sound collection channel (200) to enter the receiving groove (21), and the opening direction of the first sound inlet (211) is arranged at an angle to the extension direction of the sound collection channel (200).

8. The active noise reduction system installation structure of the range fumes extraction device according to claim 7, characterized in that: The opening direction of the first sound inlet (211) is perpendicular to the extension direction of the sound collection channel (200).

9. The active noise reduction system installation structure of the range fumes extraction device according to claim 5, characterized in that: The air duct extends vertically, and the sound collection channel (200) also extends vertically.

10. The active noise reduction system installation structure of the range fumes extraction device according to claim 7, characterized in that: An oil-proof sound-permeable membrane (28) is also provided at the first sound inlet (211).

11. The active noise reduction system installation structure of the range fumes extraction device according to claim 5, characterized in that: The sound collection channel (200) is further provided with a windproof and sound-permeable component (30) made of a porous material.

12. The active noise reduction system installation structure of the range fumes extraction device according to any one of claims 1 to 4, characterized in that: Along the sound propagation direction in the air duct (10), the position of the loudspeaker (60) is located downstream of the position of the sound collecting element (11).

13. A range hood comprising an air duct (10) and an active noise reduction system, characterized in that: The active noise reduction system is arranged on the air duct (10) using the active noise reduction system installation structure of the range fumes extraction device according to any one of claims 1 to 12.

14. The range hood according to claim 13, wherein: The range hood comprises a casing, wherein the interior space of the casing defines the air duct (10).

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