Sound acquisition device and range hood

Abstract

The sound acquisition device comprises a sound acquisition element and further comprises a shell, a sound transmission channel is defined on the shell, the sound transmission channel comprises a first channel section and a second channel section, the first channel section and the second channel section are sequentially connected, and an included angle is formed between the first channel section and the second channel section. The sound collecting element is located in the first channel section, the second channel section is provided with a second sound inlet for external sound to enter, and the shell is further provided with a section of extending wall extending in the opening direction of the second sound inlet at the second sound inlet. The sound acquisition device has the advantages that the position of pressure fluctuation caused by airflow change can be far away from the position of the sound acquisition element due to the arrangement of the extension wall on the shell, so that airflow pressure fluctuation at the acquisition position of the sound acquisition element is effectively reduced, and the sound acquisition accuracy is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of range hoods, in particular to a sound collection 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 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. 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 in an array around the fan, and the speaker assembly is distributed below the fan. For example, similar disclosures were made in the “Ranger hood and its active noise reduction device” with application number CN202221822214.3 and the “Low-noise range hood” with application number CN202222650354.3.

[0003] In order to ensure the noise reduction effect, the microphone and speaker used in the active noise reduction system 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 microphone and speaker are often contaminated, resulting in the active noise reduction system's noise reduction effect decreasing as the use time increases, or even causing failure. 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.

[0004] However, the oil-proof device of the active noise reduction device of the above-mentioned patent application still has certain deficiencies. The oil-proof device realizes sound transmission and oil prevention by means of 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 number of openings of the porous sound-permeable shell is large, 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. Therefore, how to provide a sound collection device that can effectively prevent oil and achieve the purpose of wind prevention, thereby ensuring the accuracy of sound collection has become a technical problem that needs to be urgently solved by those skilled in the art. Utility Model Content

[0005] The first technical problem to be solved by the present invention is to provide a sound collection device that can achieve the purpose of oil and wind protection and can fully collect target noise signals, thereby ensuring the accuracy of sound collection, based on the current status of the existing technology.

[0006] The second technical problem to be solved by the present invention is to provide a range hood using the above-mentioned sound collection device in view of the current status of the existing technology.

[0007] The technical solution adopted by the present invention to solve the above-mentioned technical problems is: a sound collection device, including a sound collection element and a shell, the shell defining a sound propagation channel, the sound propagation channel including a first channel section and a second channel section connected in sequence and arranged at an angle, the sound collection element being located in the first channel section, the second channel section having a second sound inlet for external sound to enter therein, and the shell further having an extended wall extending along the opening direction of the second sound inlet at the second sound inlet.

[0008] The sound collection device's sound propagation channel is designed with a first channel section and a second channel section arranged at an angle. The sound collection element is placed within the first channel section, effectively isolating the sound collection element from external airflow and preventing contamination from oil in the airflow. The angled arrangement of the first and second channel sections also creates a curved path for the sound collection device's sound propagation channel. This design attenuates high-frequency sounds (such as the high-frequency portion of wind noise and non-target noise such as high-frequency components generated by the fan system) while minimizing the impact on low-frequency sounds. Therefore, the device is well suited for propagating low-frequency noise within the collection device, facilitating accurate collection by the sound collection element. Taking into account that the sound collecting decoration is used in the air duct of the range fumes extraction device, an extended wall extending along the opening direction of the second sound inlet is provided at the second sound inlet of the shell, and a "flow dead zone" can be formed in the inner area corresponding to the extended wall. The airflow in this area is basically motionless, and the airflow pressure fluctuation cannot be transmitted, but it does not affect the transmission of sound waves. That is, the flow dead zone can block the transmission of turbulent vortex pulsation, and at the same time make the turbulent vortex further away from the sound collecting element, thereby reducing the transmission of the turbulent pulsation of the airflow to the sound collecting element, while the pressure pulsation of the noise is not affected, thereby improving the accuracy of sound collection.

[0009] The above-mentioned sound collection device is arranged in the air duct of the range fumes extraction device, the second channel section is arranged along the extension direction of the air duct, and the second sound inlet is formed at the leeward end of the shell, and the opening direction of the second sound inlet is consistent with the extension direction of the air duct.

[0010] 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 range hood device (which can be a range hood or an integrated stove) 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 space in the fan frame where the fan system is located, or it can refer to the channel structure between the fan system and the air outlet of the smoke hood.

[0011] The above-mentioned "the second channel section is arranged along the extension direction of the air duct" can be understood as the overall extension direction of the second channel section is consistent with or parallel to the extension direction of the air duct, or it can be understood as the overall extension direction of the second channel section has a slight inclination angle relative to the extension direction of the air duct.

[0012] Considering that a second channel section of sufficient length is required along the sound propagation path to prevent wind noise and reduce the impact of the duct airflow on sound collection, arranging the second channel section in the direction of the duct extension can make the entire collection device smaller in the direction perpendicular to the duct extension, that is, it occupies less space in the range hood duct, thereby reducing the wind resistance at the location of the collection device in the duct, thereby not affecting the stability of the airflow in the duct and also reducing the generation of wind noise to a certain extent. The aforementioned "leeward end of the housing" can be understood as: along the extension direction of the duct, the end of the housing adjacent to the fan system.

[0013] In order to facilitate the sound in the air duct to enter the sound propagation channel more smoothly and reduce the problem of excessive sound pressure loss caused by excessive turns during sound propagation, the first channel section has a first sound inlet connected to the second channel section, and the extension line of the opening direction of the first sound inlet is perpendicular to the extension direction of the second channel section.

[0014] The shell can be designed with an integrated structure, such as an integrated curved pipe structure, but in order to facilitate the installation of components such as sound collecting elements, the shell preferably adopts a split structure design assembled together by fasteners. The shell includes a mounting frame and a windshield. A receiving groove is provided on the front side wall of the mounting frame. The sound collecting element is placed in the receiving groove. The receiving groove constitutes the first channel section. The windshield is arranged outside the mounting frame and defines a sound collecting channel between the mounting frame and the mounting frame, which is connected to the receiving groove and located in front of the receiving groove. The sound collecting channel constitutes the second channel section. The windshield defines the second sound entrance at the leeward end with the mounting frame, and an extension wall extending along the opening direction of the second sound entrance is formed at the second sound entrance.

[0015] The term "front side" in the phrase "the sound collection channel is located in front of the receiving slot" is not limited to the actual front-to-back direction of the range hood or air duct. Instead, it should be understood as meaning that the sound collection channel is located closer to the inner center of the air duct relative to the receiving slot. For example, if the sound collection device of the present invention is mounted on the left side wall of the air duct, then "the sound collection channel is located in front of the receiving slot" should be understood as meaning that the sound collection channel is located on the right side of the receiving slot, i.e., closer to the inner center of the air duct.

[0016] The windshield of the sound collection device effectively isolates the airflow in the air duct from interfering with the sound collection element and prevents oil contamination from the airflow. The windproof and sound-permeable components in the sound collection channel also prevent oil contamination from the airflow. In particular, they effectively isolate wind noise. Even if a small amount of airflow enters the sound collection channel, the pressure pulsation is attenuated by the windproof and sound-permeable components, thereby minimizing the impact on the microphone's sound collection accuracy. Considering that the ideal noise collection method for the sound collection element is to collect the tiny pressure fluctuations generated by noise in a stable pressure flow field, since the second sound inlet is located at the leeward end of the windshield, when the airflow in the air duct passes through the top of the windshield, a sudden change in the airflow will form vortices at the second sound inlet, causing an unstable flow field. When the flow field is unstable, pressure fluctuations caused by the airflow changes will be generated. In turn, the tiny noise pressure will be overwhelmed by the airflow pressure fluctuations caused by the vortices, thereby affecting the accuracy of sound collection by the microphone. To this end, in the present invention, a sound collection channel is provided along the extension direction of the air duct, and the windshield is constructed with an extended wall at the second sound inlet that extends upward relative to the windproof and sound-permeable member. A "flow dead zone" is formed in the area inside the extended wall. In this area, the airflow is essentially still and airflow pressure fluctuations cannot be transmitted, but the transmission of sound waves is not affected. In other words, this flow dead zone blocks the transmission of turbulent vortex pulsations and simultaneously keeps the turbulent vortices away from the sound collection element, reducing the transmission of turbulent airflow pulsations to the sound collection element while unaffecting the pressure pulsations of the noise, thereby improving the accuracy of sound collection.

[0017] In order to ensure the windproof effect, the length of the extended wall should not be too small. In order to reduce the installation space occupied in the air duct, the length of the extended wall should not be too large. Preferably, the second channel section is extended vertically, and the vertical length of the wind shield is recorded as H, and the length of the extended wall is recorded as L, wherein 0.4<L / H<1.

[0018] As an improvement, to ensure effective wind protection, the sound collection element should be positioned as far away from the second sound inlet as possible. To this end, a distance is provided between the leeward end of the windshield and the sound collection element in the direction of airflow within the air duct. To ensure effective wind protection, the distance between the leeward end of the windshield and the sound collection element in the direction of airflow within the air duct is denoted as Z, with a value range of 5 mm ≤ Z ≤ 100 mm. Considering that a too small distance between the leeward end of the windshield and the sound collection element would not provide effective wind protection, the distance between the leeward end and the sound collection element should be no less than 5 mm. Of course, while still meeting wind noise protection requirements, to avoid a long sound propagation path that would result in loss of target noise transmission, the distance between the leeward end and the sound collection element should not be too large, and should not exceed 100 mm. Preferably, the value range of Z is 9 mm ≤ Z ≤ 50 mm.

[0019] The "sound collecting element" in the above-mentioned "there is a distance between the leeward end of the wind shield and the sound collecting element in the direction of airflow in the air duct" should be understood as a chip for sound collection on the circuit board (such as a microphone chip), that is, the above-mentioned distance should refer to: the distance between the leeward end of the wind shield and the position of the sound collecting chip on the circuit board in the direction of airflow in the air duct.

[0020] As an improvement, a windproof and sound-permeable member is also provided in the second channel section. This member prevents oil in the airflow from contaminating the sound collection element, and in particular effectively isolates wind noise. Even if a small amount of air enters the sound collection channel, the pressure pulsation is attenuated in the member, thereby minimizing the impact on the microphone's sound collection accuracy.

[0021] As an improvement, the front portion of the receiving groove has a first sound inlet for the sound in the sound collection channel to enter the receiving groove. Generally speaking, the windproof and sound-permeable component can be set in any section of the sound collection channel, but in order to ensure that the windproof and sound-permeable component has a sufficient extension length and improve the windproof effect, the windproof and sound-permeable component is blocked in front of the first sound inlet of the receiving groove.

[0022] Generally speaking, the opening direction of the first sound inlet can be arranged diagonally upward, diagonally downward, or forward. Generally speaking, to minimize oil contamination of the sound collecting element on the mounting frame, the orientation of the first sound inlet on the mounting frame should avoid being aligned with the extension direction of the sound collecting channel. Specifically, the opening direction of the first sound inlet should preferably be arranged at an angle to the extension direction of the sound collecting channel. However, the angle formed between the orientation of the first sound inlet and the extension direction of the sound collecting channel also needs to be reasonably designed. If the angle formed between the orientation of the first sound inlet and the extension direction of the sound collecting channel is too small, oil may still enter the receiving tank through the first sound inlet and contaminate the sound collecting element. If the angle formed between the orientation of the first sound inlet and the extension direction of the sound collecting channel is too large, the sound propagation path will bend too sharply, which will adversely affect sound propagation. Specifically, some sound pressure will be lost, hindering accurate noise collection by the sound collecting element. Therefore, to better prevent the sound collecting element from contacting oil and minimize sound pressure loss caused by the sound propagation path turning too sharply, the opening direction of the first sound inlet is forward, that is, perpendicular to the extension direction of the sound collecting channel. The sound collection channel is positioned in front of the first sound inlet of the receiving tank, with the opening of the first sound inlet perpendicular to the sound collection channel. This allows the noise in the air duct to travel along a curved path from the second sound inlet into the sound collection channel and then to the location of the sound collection element in the receiving tank. This curved path prevents excessive oil from passing directly through the sound collection channel and coming into contact with the sound collection element. Instead, it directs most of the oil to the sidewalls of the sound collection channel or the windproof and sound-permeable member, 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 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 by the sound collection element.

[0023] In order to improve the windproof effect, the windproof and sound-permeable component needs to have a sufficient length in the extension direction of the sound collection channel. To this end, the windproof and sound-permeable component extends from the position of the first sound entrance to the position of the second sound entrance.

[0024] To form the aforementioned sound collection channel and facilitate assembly of components such as the sound collection element and the windproof and sound-permeable member, the windshield includes a first side wall and a second side wall that are spaced apart and opposed to each other on both sides, and a third side wall connected between the front edges of the first and second side walls. The first and second side walls are located on the left and right sides of the mounting frame, respectively, and the third side wall is opposed to the mounting frame from front to back. The top edges of the first, second, and third side walls are all higher than the top surface of the windproof and sound-permeable member. The windshield forms a cover structure with an open rear end. During assembly, the windshield can be simply snapped onto the front side of the mounting frame.

[0025] A further improvement is that the windproof and sound-permeable member is made of a porous sound-absorbing 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 can pass through. Specifically, polyurethane foam, melamine foam, or the like 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.

[0026] In order to further improve the oil-proof effect and prevent the sound collecting element from being contaminated by oil, the receiving groove is further provided with an oil-proof sound-permeable membrane that blocks the front side of the sound collecting element.

[0027] The technical solution adopted by the present invention to solve the second technical problem is: a range hood, including an air duct for smoke to pass through and a sound collection device arranged in the air duct, wherein the sound collection device adopts the above-mentioned sound collection device.

[0028] As an improvement, the sound collecting element is a microphone.

[0029] Compared with the prior art, the advantages of this utility model are:

[0030] First, the sound collection device's sound propagation path is designed to consist of a first channel section and a second channel section arranged at an angle. The sound collection element is placed within the first channel section, effectively isolating the sound collection element from external airflow and preventing contamination from oil in the airflow. The angled arrangement of the first and second channel sections also creates a curved path for the sound collection device's sound propagation path. This design attenuates high-frequency sounds (such as the high-frequency portion of wind noise and non-target noise such as high-frequency components generated by the fan system) while minimizing the impact on low-frequency sounds. Therefore, the device is well suited for propagating low-frequency noise within the collection device, facilitating accurate collection by the sound collection element. Taking into account that the sound collecting decoration is used in the air duct of the range fumes extraction device, an extended wall extending along the opening direction of the second sound inlet is provided at the second sound inlet of the shell, and a "flow dead zone" can be formed in the inner area corresponding to the extended wall. The airflow in this area is basically motionless, and the airflow pressure fluctuation cannot be transmitted, but it does not affect the transmission of sound waves. That is, the flow dead zone can block the transmission of turbulent vortex pulsation, and at the same time make the turbulent vortex further away from the sound collecting element, thereby reducing the transmission of the turbulent pulsation of the airflow to the sound collecting element, while the pressure pulsation of the noise is not affected, thereby improving the accuracy of sound collection.

[0031] Secondly, in the preferred solution, considering that a windproof and sound-permeable component of sufficient length needs to be set on the sound propagation path to prevent wind noise in order to reduce the influence of the airflow in the duct on sound collection, the second channel section used to place the windproof and sound-permeable component is arranged in the extension direction of the air duct, so that the size of the entire sound collection device in the direction perpendicular to the extension direction of the air duct can be made smaller, that is, the space occupied in the air duct of the range hood is smaller, thereby making the wind resistance at the position where the sound collection device is located in the air duct smaller, so that it will not affect the stability of the airflow in the air duct, and at the same time also reduce the generation of wind noise to a certain extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a schematic diagram of the three-dimensional structure of the sound collection device according to an embodiment of the utility model;

[0033] Figure 2 This is an exploded view of the sound collection device according to an embodiment of the present utility model;

[0034] Figure 3 A vertical cross-sectional view of a sound collection device according to an embodiment of the present invention;

[0035] Figure 4 for Figure 3 Schematic diagram of the structure after omitting the windproof and sound-permeable components;

[0036] Figure 5 For the Figure 3 Sectional view cut along the AA direction;

[0037] Figure 6 This is a schematic diagram of the three-dimensional structure of the sound collection device of an embodiment of the utility model installed in the air duct;

[0038] Figure 7 for Figure 6 a transverse cross-sectional view cut along the anterior-posterior direction;

[0039] Figure 8 Schematic diagram of the sound propagation process at the first sound inlet of the mounting frame;

[0040] Figure 9 This is a schematic diagram of the airflow acting on the sound collection device in the air duct according to an embodiment of the present invention;

[0041] Figure 10 Schematic diagram of the propagation paths of noise sound pressure and airflow turbulence pressure. DETAILED DESCRIPTION

[0042] The present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

[0043] 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.

[0044] Figure 1-Figure 7 A preferred embodiment of the sound collection device and range hood of the present invention is shown.

[0045] The sound collection device includes a sound collection element 11 and a housing 2. The housing 2 defines a sound propagation channel, which includes a first channel section and a second channel section connected in sequence. The sound collection element 11 is located in the first channel section. The first channel section has a first sound inlet 211 connected to the second channel section. The second channel section has a second sound inlet 45 for external sound to enter. The extension line of the opening direction of the first sound inlet 211 intersects the extension line of the opening direction of the second sound inlet 45. In a preferred embodiment, the first and second channel sections are both linear channels, wherein the extension line of the first channel section intersects the extension line of the second channel section. The extension line of the first channel section can be understood as the line connecting the location of the sound inlet of the channel section to the location of the sound collection element 11, and the extension line of the second channel section can be understood as the line connecting the location of the sound inlet of the channel section to the location of the sound outlet.

[0046] An active noise reduction system is typically installed in the air duct 10 of a range hood (such as a range hood or a kitchen appliance with a range hood extraction function, such as an integrated stove). The sound collection device, a key component of the active noise reduction system, is also installed in the range hood's air duct 10. Taking a range hood as an example, the "air duct" mentioned above can refer to the range hood's casing or a box structure with a separate "channel" for oil fumes to pass through, such as the channel between the fan system and the range hood's fume collection hood in a ceiling-mounted range hood. The active noise reduction system generally includes a sound collection element 11 (typically a microphone) and a speaker. The microphone collects the noise generated by the range hood during operation and transmits the collected noise waves as electrical signals to a controller. The controller analyzes and processes the noise and issues a command to the speaker, controlling it to emit sound waves that match the noise waves, thereby neutralizing the noise and achieving the desired noise reduction effect. The sound collection device of this embodiment can be used to mount the sound collection element 11 and provide protection against oil and wind.

[0047] The sound collection device is located below the fan system. This means that the noise generated by the fan system propagates downward along the air duct 10, and the sound collection device is positioned precisely along this path within the duct 10. In addition to the housing, the sound collection device also includes an oil-proof, sound-permeable membrane 28 and a windproof, sound-permeable member 30. The housing also includes a mounting bracket 20 and a windshield 40.

[0048] This embodiment takes the case 1 having a "channel" for oil smoke to pass through separately as an example to illustrate the installation structure of the sound collection device. The channel in the case 1 serves as the air duct 10. The mounting bracket 20 can be mounted on the rear side wall of the air duct 10. A receiving groove 21 for placing the sound collection element 11 is provided on the front side wall thereof. The receiving groove constitutes the first channel section of the above-mentioned shell 2. The front portion of the receiving groove 21 has an opening as a first sound inlet 211 for sound to enter the receiving groove 21. The first sound inlet 211 should be understood as an opening for sound from the outside (the sound collection channel in this embodiment) to enter the receiving groove 21 and be effectively collected by the sound collection element, such as Figure 8 The circumferential opening defined by boundary points A1 and A2 of the middle receiving groove 21 does not necessarily refer to the maximum opening at the front of the receiving groove 21. When the mounting bracket 20 is properly installed on the rear side wall of the air duct 10, the rear wall of the mounting bracket 20 where the receiving groove 21 is located is in contact with the rear side wall of the air duct 10.

[0049] 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 connected to the sidewalls of the air duct 10 or to a beam within the air duct 10 via screws. A forward-extending connecting post 265 is provided in the lower region of the receiving slot 21 of the mounting frame 20. The wind shield 40 is connected to the connecting post 265 of the mounting frame 20 via screws 50.

[0050] 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 3The 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. Furthermore, considering that an excessively large inclination angle of the guide surface 4130 toward the interior of the air duct 10 could affect the flow of air within the air duct 10 to a certain extent, such as affecting the air volume flowing within the air duct 10 or generating additional noise, the inclination angle of the guide surface 4130 of the wind shield 40 needs to be appropriately designed. The angle formed between the guide surface 4130 of the wind shield 40 and the sidewall of the air duct 10 on which the wind shield 40 is mounted is denoted as A, with a value range of A ≤ 60°. To reduce the impact of the installation of the sound collection device on the flow field within the air duct 10, the dimension of the air duct 10 in the front-to-back direction of this embodiment is denoted as a, and the distance that the wind shield 40 protrudes forward relative to the sidewall of the air duct 10 on which the wind shield 40 is mounted is denoted as b. Considering that if the distance that the wind shield 40 protrudes forward is too large, such as b / a>0.35, on the one hand, it will affect the air volume flowing in the air duct 10, and on the other hand, it will also cause the air flow to be disturbed at the position where the sound collection device is located in the air duct 10, generating additional noise and affecting the accuracy of sound collection, the value of b / a needs to be reasonably limited. In this embodiment, preferably, b / a≤0.35, see Figure 7 .

[0051] In order to improve the oil-proof effect, the windshield 40 of this embodiment can be made of plastic or metal.

[0052] In this embodiment, the windshield 40 and the front side of the mounting frame 20 form a vertically extending gap between them 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). This gap serves as the sound collection channel 200. Located on the front side of the mounting frame 20, this sound collection channel 200 constitutes the second channel section of the housing 2. 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 section of the range hood's fan system along the air duct's extension direction) and the front sidewall of the mounting frame 20. The opening direction B4 of the second sound inlet 45 faces upward. In this embodiment, both the air duct 10 and the sound collection channel 200 extend vertically, meaning that the sound collection channel 200 extends in the same direction B2 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., a section along the extension direction of the air duct, near the range hood's fan system) and the front side wall of the mounting frame 20. Considering that the ideal noise collection method for the sound collection element 11 is to collect tiny pressure fluctuations generated by noise in a pressure-stable flow field, since the second sound inlet 45 is located at the leeward end of the windshield 40, when the airflow in the air duct 10 passes through the top of the windshield 40, the sudden change in the airflow will cause the flow field to become unstable. When the flow field is unstable, pressure fluctuations caused by the change in the airflow will occur, causing the tiny noise pressure to be covered by the airflow pressure fluctuations, thereby affecting the accuracy of the sound collection by the sound collection element 11. Specifically: See Figure 10 The target noise sound pressure and airflow turbulence pressure are both pressure pulsations in the air. One of the main differences between the two is that the magnitude of the sound wave is relatively small, 2 to 3 orders of magnitude smaller than the airflow pressure pulsation. Therefore, when the microphone collects data, if both pressure pulsations are collected at the same time, the sound pressure pulsation is often covered by the airflow pressure pulsation, resulting in the inability to accurately collect noise. In the present application, turbulent vortices are generated when the airflow passes through the protective cover shell, and these turbulent vortices will cause pressure pulsations of the airflow, and the pressure pulsations will be transmitted to the microphone through the gaps in the windproof and sound-permeable component 30 and the oil-proof and sound-permeable membrane 28 and be collected, thereby affecting the accuracy of noise collection. On the other hand, these turbulences themselves will also generate secondary noise, and the existence of secondary noise will also affect the accuracy of main noise collection. In order to solve the above technical problems, the windshield 40 in this embodiment is constructed to have an extension wall 46 extending along the opening direction of the second sound inlet 45 (that is, extending along the direction of airflow in the air duct 10) at the second sound inlet 45, wherein the vertical length of the windshield 40 is recorded as H, and the length of the extension wall 40 is recorded as L, wherein 0.4<L / H<1, which forms a "flow dead zone" in the inner area corresponding to the extension wall 46 (see for details). Figure 9), the airflow in this area is basically motionless, and the airflow pressure fluctuations cannot be transmitted, but the transmission of sound waves is not affected, that is, the flow dead zone blocks the transmission of turbulent vortex pulsation, and at the same time makes the turbulent vortex further away from the sound collection element, reducing the transmission of the turbulent pulsation of the airflow to the sound collection element, while the pressure pulsation of the noise is not affected, thereby improving the accuracy of sound collection.

[0053] The distance between the end of the extension wall 46 of the windshield 40 and the sound collecting element 11 in the direction of airflow in the air duct 10 is recorded as Z. Considering that the distance between the end of the extension wall 46 and the sound collecting element 11 is too small to effectively prevent wind, the distance between the two should be no less than 5 mm. Of course, on the basis of meeting the requirements of wind noise prevention, in order to avoid the loss of target noise due to the long sound propagation path, the distance between the two should not be too large and should not exceed 100 mm. That is, the value range of Z is: 5 mm ≤ Z ≤ 100 mm. Preferably, the value range of Z is: 9 mm ≤ Z ≤ 50 m.

[0054] The air duct 10 of this embodiment also extends vertically, that is, the extension direction of the sound collection channel 200 is consistent with the extension direction B2 of the air duct 10. The opening direction B1 of the first sound inlet 211 intersects with the extension direction B3 of the sound collection channel 200 to form a first angle M. If the first angle M formed between the orientation B1 of the first sound inlet 211 and the extension direction B3 of the sound collection channel 200 is too small, oil may still enter the receiving groove 21 through the first sound inlet 211 and contaminate the sound collection element 11. If the first angle M formed between the orientation B1 of the first sound inlet 211 and the extension direction B3 of the sound collection channel 200 is too large, the sound propagation path will make a sharp turn, which will adversely affect sound propagation. In other words, some sound pressure will be lost, which is not conducive to accurate noise collection by the sound collection element. Therefore, the first angle M formed between the orientation of the first sound inlet 211 and the extension direction B3 of the sound collection channel 200 should also be reasonably designed. Preferably, in this embodiment, the first angle M is 90°, that is, the opening direction B1 of the first sound inlet 211 is perpendicular to the extension direction B3 of the sound collection channel 200.

[0055] 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.

[0056] 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 set at a certain angle 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. This keeps the sound collection element 11 as far away from the oil as possible, thereby 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.

[0057] The oil-proof sound-permeable membrane 28 covers the first sound inlet 211 of the receiving groove 21 of the mounting frame 20, specifically, it is installed at the edge of the front opening of the receiving groove 21 of the mounting frame 20. More specifically, in order to facilitate the installation of the oil-proof sound-permeable membrane 28 and ensure its sealing after installation, the receiving groove 21 is further formed with an annular step portion 210 at the edge of its first sound inlet 211, and the oil-proof sound-permeable membrane 28 is arranged on the annular step portion 210. In order to ensure the oil-proof performance of the oil-proof sound-permeable membrane 28 and enable it to effectively transmit sound waves, the oil-proof sound-permeable membrane 28 of this embodiment is preferably a polyethylene film. Among them, Figure 3 As shown, there is a fourth distance, denoted as f, between the oil-proof sound-permeable membrane 28 and the sound collecting element 11. This fourth distance is denoted as f, with a value range of f ≥ 2 mm. This prevents contact with the sound collecting element 11 due to membrane 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 28. In other words, the oil-proof sound-permeable membrane 28 may partially contact other components of the circuit board where the microphone chip resides (such as solder joints or fixing screws). The windproof sound-permeable member 30 does not directly contact the oil-proof sound-permeable membrane 28 to ensure oil-proofing. Specifically, there is a sixth distance, denoted as n, 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. In order to avoid the oil-proof sound-permeable membrane 28 from contacting the windproof sound-permeable component 30 and affecting the sound transmission effect there, the sixth distance n between the oil-proof sound-permeable membrane 28 and the windproof sound-permeable component 30 should be greater than 0.1mm, preferably in the range of 0.5mm to 3mm.

[0058] 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.

[0059] The windproof and sound-permeable component 30 of this embodiment includes an extension section 301 extending upward from the top edge of the first sound inlet 211 of the accommodating groove 21, and the length of the extension section 301 of the windproof and sound-permeable component 30 is recorded as h, and the dimension of the first sound inlet 211 of the accommodating groove 21 in the up and down directions is m, wherein the value range of h / m is: 0.125≤h / m≤0.6. Since the sound collection channel 200 has a vertical section extending vertically and a horizontal section extending front to back, that is, there is a turning portion at the first sound inlet 211 of the receiving groove 21, if the extension length of the outer peripheral edge portion of the windproof and sound-permeable component 30 relative to the edge of the first sound inlet 211 of the receiving groove 21 is too short (for example, h / m is less than 0.125), it will also be affected by a large amount of wind noise. After the above parameter design is performed, the windproof effect of the windproof and sound-permeable component is effectively guaranteed, and the impact on the accuracy of sound collection caused by the excessively short extension length of the outer peripheral edge of the windproof and sound-permeable component is avoided. Of course, considering the adverse effect of the windproof and sound-permeable component 30 on sound attenuation, the length of the extension section 301 of the windproof and sound-permeable component 30 should not be too large. If h / m is greater than 0.6, the sound will not be able to effectively meet the sound pressure requirements of the sound collection element 11 when it propagates to the receiving groove 21, thereby reducing the accuracy of noise collection.

[0060] To prevent the windproof and sound-permeable member 30 from contacting the oil continuously flowing down the sidewall of the air duct 10, a first spacing is provided between the windproof and sound-permeable member 30 and the rear sidewall of the air duct 10 after being installed on the mounting bracket 20. This first spacing is denoted as d, where the value range of d is d ≥ 4 mm. Similarly, to ensure windproofing, the main body of the windproof and sound-permeable member 30 has a front-to-back dimension (i.e., thickness) denoted as e, where the value range of e is 40 mm ≥ e ≥ 3 mm. Specifically, when e ≥ 3 mm, the windproof and sound-permeable member 30 can effectively prevent the airflow in the air duct from directly impacting the sound collecting element 11. Of course, considering the adverse effect of the windproof ball 30 (generally made of a porous material that is resistant to airflow disturbances and is sound-permeable) on sound attenuation, the front-to-back dimension (i.e., thickness) of the windproof and sound-permeable member 30 cannot be too large, and needs to be e ≤ 40 mm. At the same time, when the size (i.e., thickness) of the windproof and sound-permeable component 30 in the front-to-back direction is constant, the size d1 of the main body of the windproof and sound-permeable component 30 in the left-to-right direction must also be adapted thereto, that is, e / d1 needs to be reasonably limited. Specifically, if e / d1 is too small (such as e / d1 < 0.2), it means that the main body of the windproof and sound-permeable component 30 is larger in the left-to-right direction, and the area of its upper part in contact with oil and dirt increases, which will directly affect the service life of the windproof and sound-permeable component 30. If e / d1 is too large (such as e / d1 > 0.5), it means that the main body of the windproof and sound-permeable component 30 is smaller in the left-to-right direction, which is not conducive to the transmission of sound from a larger lateral angle range above to the sound collection channel 200, affecting the accuracy of sound collection.

[0061] Due to the placement of the windproof, sound-permeable member 30 in the sound collection channel 200, there is a certain amount of loss in the sound propagation path from the second sound inlet 45 to the location of the sound collection element 11. This results in a loss of sound pressure. Therefore, it is necessary to ensure that a sufficient amount of the noise to be collected enters the receiving slot 21 of the mounting bracket 20 to be received by the sound collection element 11 and accurately capture the noise signal. Specifically, the principles of sound attenuation and compensation are as follows:

[0062] L w =L1-ΔL+10lgS0

[0063] The noise energy that the sound collection component can collect per unit time is the sound power L w ;

[0064] When the sound reaches the top surface of the windproof and sound-permeable member 30, the sound pressure is L1;

[0065] Due to the weakening effect of the windproof and sound-permeable member 30, the sound pressure of the loss noise is ΔL;

[0066] an area S0 of a cross section at the second sound inlet 45 of the sound collecting channel 200;

[0067] Therefore, if the thickness of the windproof sound-permeable member 30 or the length thereof in the sound propagation path is too large, resulting in serious sound attenuation, the sound power L collected by the sound collecting element can be guaranteed by increasing S0. w Specifically, the ratio of the cross-sectional area S0 of the second sound inlet 45 of the sound collection channel 200 to the area S of the first sound inlet 211 at the front of the receiving groove 211 in this embodiment needs to be reasonably limited, where S0 / S ≥ 0.18. This ensures that sufficient noise can pass through the sound collection channel 200 of the sound collection device to compensate for the sound pressure loss caused by the provision of the windproof and sound-permeable member 30, thereby ensuring that the sound can meet the sound pressure requirements of the sound collection element 11 when it propagates to the second sound inlet 45, further improving the accuracy of noise collection.

[0068] On the other hand, the vertical dimension of the main body of the windproof and sound-permeable member 30 in this embodiment is denoted as g. To match the dimension of the first sound inlet 211 at the front of the receiving slot and ensure windproof performance, 100mm ≥ g ≥ 10mm. The cross-sectional area of the main body of the windproof and sound-permeable member 30 adjacent to the second sound inlet 45 is S1. Here, g / 2 + e / 2 represents the length of the sound propagation path in the windproof and sound-permeable member. When the propagation path is long, the sound loss is high. According to the sound propagation principle, L w =L1+101gS(L W (where L1 is the sound power, L2 is the sound pressure, and S is the area at the sound entrance) It can be seen that due to sound loss, the sound pressure decreases during sound propagation. As compensation, S1 should be increased to ensure that enough sound is collected by the sound collection element. Therefore, considering the sound propagation loss and compensation, the value of S1 / (g / 2+e / 2) should be greater than 8mm, and the preferred value range is: 10mm-15mm. If S1 / (g / 2+e / 2) is too small, such as S1 / (g / 2+e / 2)≤8, it means that the entrance area of the windproof and sound-permeable member near the end of the second sound entrance for effective sound transmission from top to bottom is small, and the amount of sound entering is insufficient to offset the adverse effects of the windproof and sound-permeable member 30 on sound loss in the vertical direction and the front-back direction, thereby reducing the accuracy of sound collection by the sound collection element 11. If S1 / (g / 2+e / 2) is too large, such as S1 / (g / 2+e / 2)≥15, it means that the entrance area of the windproof and sound-permeable component 30 at the end position adjacent to the second sound entrance 45 for effective transmission of sound from top to bottom is large. Similarly, the area of the upper part of the windproof and sound-permeable component 30 that contacts oil and dirt increases, affecting the service life of the windproof and sound-permeable component 30.

[0069] In this embodiment, since the windproof and sound-permeable member 30 is filled in the sound collection channel 200, that is, there is no gap between the front side of the windproof and sound-permeable member 30 and the wind shield 40, the cross-sectional area S1 of the main body of the windproof and sound-permeable member 30 adjacent to the second sound inlet 45 is substantially consistent with the cross-sectional area S0 of the second sound inlet 45 of the sound collection channel 200.

[0070] In this embodiment, after the sound collection element 11 is installed in the receiving slot 21 of the mounting frame 20, an oil-proof, sound-permeable membrane 28 is installed at the first sound inlet 211, and a windproof, sound-permeable member 30 is installed outside the first sound inlet 211. Furthermore, a windshield 40 is installed outside the windproof, sound-permeable member 30. This sound collection device utilizes these three layers of protection to effectively eliminate wind noise and prevent oil contamination. After the windshield 40 covers the windproof, sound-permeable member 30, a second sound inlet 45 is reserved at the leeward end, communicating with the outside world. Due to airflow patterns, the flow in the area adjacent to the windproof, sound-permeable member 30 is in a low-speed, high-static-pressure region. The presence of this low-speed, high-static-pressure region reduces wind noise in this region, thereby ensuring that the target noise to be collected (i.e., the noise of the fan system) can be effectively transmitted through the second sound inlet 45 to the receiving slot 21 of the mounting frame 20, thus ensuring the accuracy of noise data collection. On the other hand, considering the impact of the windproof and sound-permeable component 30 and the windproof cover 40 on the obstruction and loss of sound propagation, the ratio of the area S at the first sound entrance of the accommodating groove 21 to the area S0 at the second sound entrance 45 of the sound collection channel 200 is limited within a reasonable value range, which can ensure that enough noise passes through the sound collection device and is received by the sound collection element, further improving the accuracy of noise collection.

[0071] 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. A sound collection device, comprising a sound collection element (11), characterized in that: The invention also includes a shell (2), which defines a sound propagation channel. The sound propagation channel includes a first channel section and a second channel section that are connected in sequence and arranged at an angle. The sound collecting element (11) is located in the first channel section. The second channel section has a second sound inlet (45) for external sound to enter. The shell (2) also has an extension wall (46) at the second sound inlet (45) that extends along the opening direction (B4) of the second sound inlet (45).

2. The sound collection device according to claim 1, wherein: The above-mentioned sound collection device is arranged in the air duct (10) of the range fumes extraction device, the second channel section is arranged along the extension direction of the air duct (10), and the second sound inlet (45) is formed at the leeward end of the shell (2), and the opening direction (B4) of the second sound inlet (45) is consistent with the extension direction of the air duct.

3. The sound collection device according to claim 2, characterized in that: The first channel section has a first sound inlet (211) communicating with the second channel section, and an extension line of the opening direction of the first sound inlet (211) is perpendicular to an extension direction of the second channel section.

4. The sound collection device according to claim 2 or 3, characterized in that: The shell (2) includes a mounting frame (20) and a windshield (40). A receiving groove (21) is provided on the front side wall of the mounting frame (20). The sound collecting element (11) is placed in the receiving groove (21). The receiving groove (21) constitutes the first channel section. The windshield (40) is arranged outside the mounting frame (20) and defines a sound collecting channel (200) between the windshield (40) and the mounting frame (20) that is connected to the receiving groove (21) and located in front of the receiving groove (21). The sound collecting channel (200) constitutes the second channel section. The windshield (40) defines the second sound inlet (45) at the leeward end with the mounting frame (20), and an extension wall (46) is formed at the second sound inlet (45) that extends along the opening direction (B4) of the second sound inlet (45).

5. The sound collection device according to claim 4, characterized in that: The second channel section extends vertically, the vertical length of the wind shield (40) is recorded as H, and the length of the extension wall is recorded as L, wherein 0.4<L / H<1.

6. The sound collection device according to claim 4, characterized in that: There is a distance Z between the end of the extension wall (46) and the sound collecting element (11) in the direction of air flow in the air duct (10), and the value range of Z is: 5mm≤Z≤100mm.

7. The sound collection device according to claim 4, characterized in that: A windproof and sound-permeable component (30) is also provided in the second channel section.

8. The sound collection device according to claim 7, characterized in that: The front portion of 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 windproof sound-permeable member (30) is blocked on the front side of the first sound inlet (211) of the receiving groove (21).

9. The sound collection device according to claim 8, characterized in that: The windproof and sound-permeable member (30) extends from the location of the first sound inlet (211) to the location of the second sound inlet (45).

10. The sound collection device according to claim 8, characterized in that: The sound collection channel (200) and the air duct (10) both extend vertically, and the end edge of the extension wall (46) is higher than the top surface of the windproof and sound-permeable component (30).

11. The sound collection device according to claim 10, characterized in that: The windshield (40) includes a first side wall (411), a second side wall (412) and a third side wall (413) connected between the front edge of the first side wall (411) and the front edge of the second side wall (412), respectively. The first side wall and the second side wall are located on the left and right sides of the mounting frame, respectively. The third side wall (413) is opposite to the mounting frame (20) front and back. The top edges of the first side wall (411), the second side wall (412) and the third side wall (413) are all higher than the top surface of the windproof and sound-permeable component (30).

12. A range hood comprising an air duct (10) for smoke to pass through and a sound collecting device arranged in the air duct (10), characterized in that: The sound collection device is the sound collection device according to any one of claims 1 to 11.

13. The range hood according to claim 12, wherein: The sound collecting element (11) is a microphone.

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