Sound acquisition device and range hood

Abstract

The sound collection device comprises a sound collection 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 which are connected in sequence and arranged in an included angle mode, the sound collection element is located in the first channel section, and the sound collection element is located in the second channel section. The second channel section is provided with a second sound inlet for external sound to enter, a windproof sound transmission part is further arranged in the second channel section, and a gap channel extending along the second channel section is further formed between the windproof sound transmission part and the inner wall of the second channel section and serves as a sound supplementing channel. The sound collection device has the advantages that the sound supplement channel can ensure that enough noise can pass through the sound transmission channel of the sound collection device to compensate the sound pressure lost due to the arrangement of the windproof sound transmission part, so that the sound pressure requirement of the sound collection element can be met when the sound is transmitted to the position where the sound collection element is located; and the accuracy of noise acquisition is further 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 for purifying the kitchen environment. The noise of the range hood has always been one of the main problems troubling users. As a new noise reduction technology, active noise reduction is also considered to be applied to the range hood for noise reduction. The active noise reduction device usually includes a microphone and a speaker, that is, the microphone collects the noise generated when the range hood is working, and the collected noise sound wave is transmitted to the controller in the form of an electrical signal. After being analyzed and processed by the controller, an instruction is sent to the speaker to control the speaker to emit a sound wave matching the noise sound wave to neutralize the noise sound wave, so as to achieve the noise reduction effect. For example, the Chinese invention patent application with the application number CN202010935185.0 (the application publication number is: CN111928310A) discloses such a range hood with active noise reduction function. The microphone of this range hood is arranged inside the casing and surrounds the blower in an array distribution manner, and the speaker assembly is distributed below the blower. Another example is the "Range Hood and Its Active Noise Reduction Device" with the application number CN202221822214.3 and the "Low-Noise Range Hood" with the application number CN202222650354.3, which also have similar disclosures.

[0003] In order to ensure the noise reduction effect, the microphones and speakers used in the existing active noise reduction systems are often arranged inside the 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 a reduction in the noise reduction effect of the active noise reduction system over time and even failures. For this reason, the Chinese utility model patent application with the application number CN201820250745.7 discloses an active noise reduction device for a range hood with an oil-proof device, including an input device, a central data processor, and a noise reduction unit. The input device includes a microphone, and the microphone is arbitrarily installed at a place on the range hood. The noise reduction unit includes at least two noise reduction boxes, which are arranged at the bottom of the volute of the range hood and face the air inlet. An oil-proof device is arranged below the noise reduction box, and the oil-proof device is also arranged at the bottom of the volute and covers the noise reduction box. The oil-proof device includes a porous sound-permeable shell and an oil-proof sound-permeable film attached to the surface of the porous sound-permeable shell. At least one noise reduction speaker is arranged inside the noise reduction box. The microphone and the noise reduction speaker are both connected to the central data processor. The central data processor loads a self-check module and an oil contamination detection module for the noise reduction device. The oil contamination detection module detects the oil contamination of the oil-proof device, and the self-check module receives and processes the self-system signals reported by the device to determine whether there is an increase in the microphone and the noise reduction speaker. At the same time, a timing detection module is arranged inside the self-check module.

[0004] However, the oil-proof device of the active noise reduction device in the above patent application still has certain deficiencies. The oil-proof device realizes sound transmission and oil prevention through a porous sound-permeable shell and an oil-proof sound-permeable film attached to the surface of the porous sound-permeable shell. It does not consider the influence of wind noise in the air duct of the range hood, that is, no effective wind prevention treatment is carried out, 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, so as to ensure the accuracy of sound collection has become a technical problem that needs to be solved urgently by those skilled in the art. Summary of the Invention

[0005] The first technical problem to be solved by the present invention is to provide a sound collection device that can effectively prevent oil and achieve the purpose of wind prevention, so as to ensure the accuracy of sound collection, in view of the current situation of the prior art.

[0006] The second technical problem to be solved by the present invention is to provide a range hood that applies the protection device of the above active noise reduction system, in view of the current situation of the prior art.

[0007] The technical solution adopted by the present invention to solve the above first technical problem is as follows: A sound collection device includes a sound collection element and also includes a housing. A sound transmission channel is defined on the housing. The sound transmission channel includes a first channel section and a second channel section that are connected in sequence and arranged at an angle. The sound collection element is located in the first channel section. The second channel section has a second sound inlet for external sound to enter. A windproof sound-permeable member is also provided in the second channel section. A gap channel extending along the second channel section is provided between the windproof sound-permeable member and the inner wall of the second channel section as the sound supplement channel.

[0008] First, place the sound collection element into the first channel section of the sound collection device, which can effectively isolate the interference of external airflows on the sound collection element and prevent the oil stains in the airflows from contaminating the sound collection element. The windproof and sound-permeable element set in the second channel section can prevent the oil stains in the airflows from contaminating the sound collection element. In particular, it can effectively isolate wind noise. Even if a small amount of airflows enter the sound collection channel, the pressure pulsation can be weakened in the windproof and sound-permeable element, thereby reducing the impact on the sound collection accuracy of the microphone. The first channel section and the second channel section in the housing are arranged at an angle, so that the entire sound propagation path of the noise in the air duct entering the second channel section from the second sound inlet and then propagating to the position of the sound collection element in the first channel section is a turning path. This turning path can prevent excessive oil stains from directly passing through the sound propagation channel and contacting the sound collection element, but make most of the oil stains adhere to the side wall of the corresponding channel section or the windproof and sound-permeable element. Thus, the sound collection element can be as far away from the oil stains as possible, extending the service life of the sound collection element. On the other hand, the sound propagation path in the sound collection device adopts a turning path design, which has a weakening effect on high-frequency sounds (such as the high-frequency sound part in wind noise and the high-frequency sound components generated by the fan system and other non-target noises), and has less impact on low-frequency sounds. Therefore, it can be better applied to the propagation of low-frequency noises in the sound collection device, facilitating the accurate collection of low-frequency noises by the sound collection element. The main reason is that the wavelength of low-frequency noises is longer, and it can better adapt to the bending and irregular shapes of the pipeline. When low-frequency noises propagate in a bent pipeline, due to their longer wavelengths, they are not easily blocked and reflected by the pipeline, so they can better propagate and spread. While the wavelength of high-frequency noises is shorter, and they are easily reflected and absorbed by the shape and bending of the pipeline. Therefore, it is more difficult for high-frequency noises to propagate and spread in the pipeline compared to low-frequency noises. Since the windproof and sound-permeable element is set in the second channel section and the sound propagation path is a turning path, it will have an adverse impact on sound propagation, that is, a part of the sound pressure will be lost. According to the sound propagation principle L w = L1 + 10lgS (L W is the sound power, L1 is the sound pressure, and S is the area at the sound inlet). When the sound pressure L1 is lost, as a compensation, a sound replenishment channel extending along the second channel section is reserved between the inner wall of the second channel section and the windproof and sound-permeable element. This sound replenishment channel can ensure that sufficient noise can pass through the sound propagation channel of the sound collection device, compensating for the sound pressure lost due to the setting of the windproof and sound-permeable element, and further ensuring that the sound can meet the sound pressure requirements of the sound collection element when propagating to the position of the sound collection element, further improving the accuracy of noise collection.

[0009] As an improvement, the above-mentioned sound collection device is arranged in the air duct of the oil fume suction device. The second channel section is arranged along the extension direction of the air duct, and the second sound inlet is formed at one end of the housing facing away from the wind. 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 collecting hood of the oil fume suction 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 collecting hood, or the space inside the fan frame where the fan system is located, or the channel structure between the fan system and the air outlet of the smoke collecting hood.

[0011] The above-mentioned "the second channel section is arranged along the extension direction of the air duct" can be understood as that 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 also be understood that the overall extension direction of the second channel section has a certain inclination angle relative to the extension direction of the air duct.

[0012] Considering that a sufficient length of sound collection channel needs to be set on the sound propagation path for wind noise prevention to reduce the influence of the air duct airflow on sound collection, arranging the sound collection channel in the extension direction of the air duct can make the size of the entire collection device in the direction perpendicular to the extension direction of the air duct smaller, that is, it occupies less space in the air duct of the range hood, and thus makes the wind resistance at the position of the collection device in the air duct smaller, so it will not affect the stability of the airflow in the air duct, and at the same time, it also reduces the generation of wind noise to a certain extent. The above-mentioned "one end of the housing facing away from the wind" can be understood as: along the extension direction of the air 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, the first channel section has a first sound inlet communicating with 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 housing can be designed with an integrated structure, such as a bent pipe structure with an integrated design. However, for the convenience of installing components such as sound collection elements, the housing is preferably designed with a split structure assembled with fasteners. The housing includes a mounting rack and a windproof cover. A receiving groove is formed on the front side wall of the mounting rack, and the sound collection element is placed in the receiving groove. The receiving groove constitutes the first channel section. The windproof cover covers the outside of the mounting rack and defines a sound collection channel communicating with the receiving groove and located in front of the receiving groove between the windproof cover and the mounting rack. This sound collection channel constitutes the second channel section. The windproof cover and the mounting rack define the second sound inlet at the end facing away from the wind. A sound supplement channel is also reserved between the windproof sound-transmitting member and the windproof cover.

[0015] The sound collection channel can be a linear channel structure or a non-linear channel structure with local bends or curves. To avoid adverse effects on sound propagation due to excessive turns in the sound propagation path within the protection device and to consider the convenience of installing components such as the windproof sound-permeable member within the sound collection channel, the extension direction of the main body of the sound collection channel is the same as the extension direction of the air duct. Generally speaking, to minimize the contamination of the sound collection element on the mounting bracket by oil stains, the orientation of the first sound inlet on the mounting bracket should be avoided to be the same as the extension direction of the sound collection channel, that is, the opening direction of the first sound inlet and the extension direction of the sound collection channel should be set at an angle. However, the angle formed between the orientation of the first sound inlet and the extension direction of the sound collection 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 collection channel is too small, the oil fluid will still enter the receiving groove through the first sound inlet to contaminate the sound collection element. If the angle formed between the orientation of the first sound inlet and the extension direction of the sound collection channel is too large, the sound propagation path will have too large a turn, which will have an adverse effect on sound propagation, that is, a part of the sound pressure will be lost, which is not conducive to the accurate collection of noise by the sound collection element. Therefore, in order to better avoid the sound collection element from contacting oil stains and improve the windproof effect, the extension directions of both the sound collection channel and the air duct are vertically extended, the opening of the second sound inlet faces upward, the front opening of the receiving groove forms a first sound inlet communicating with the sound collection channel, and the opening direction of the first sound inlet is perpendicular to the extension direction of the sound collection channel.

[0016] To improve the windproof effect and ensure the accuracy of original noise collection, the distance between the part of the windproof cover located in front of the windproof sound-permeable member and the windproof sound-permeable member is denoted as c, and the dimension of the main body of the windproof sound-permeable member in the front-rear direction is denoted as e. Among them, the value range of c / e is: 0.1 ≤ c / e ≤ 0.45. If the value of c / e is too small (such as less than 0.1), it means that the size of the sound compensation channel is relatively small. Although it can suppress wind noise, the sound compensation effect is limited and is not sufficient to compensate for the sound pressure lost due to the setting of the windproof sound-permeable member. If the value of c / e is too large (such as greater than 0.45), it means that the size of the sound compensation channel is relatively large. Although it meets the purpose of compensating for the sound pressure lost due to the setting of the windproof sound-permeable member, it also means that the windproof effect of the windproof sound-permeable member will be weakened, resulting in a certain degree of damage to the audio signal of the target noise to be collected by the wind noise.

[0017] As an improvement, the value range of the distance between the part of the windproof cover located in front of the windproof sound-permeable member and the windproof sound-permeable member is: 0.5mm ≤ c ≤ 2mm.

[0018] For further improvement, the windproof sound-permeable member is a sound-permeable member made of porous sound-absorbing material. Using a sound-permeable member made of damping materials such as porous sound-absorbing materials as the windproof sound-permeable member can slow down the airflow, eliminate the airflow impact, and also ensure that the sound to be collected can pass through. Specifically, the windproof sound-permeable member can be made of polyurethane foam, melamine foam sponge, etc. The windproof sound-permeable member can avoid the airflow impact on the oil-proof sound-permeable membrane and generate additional noise, and the property of its porous material itself can absorb the high-frequency components in the sound energy, realizing the function of filtering the noise signal.

[0019] As an improvement, the area of the cross-section of the windproof sound-permeable member near the second sound inlet is denoted as S1, the area of the cross-section of the sound supplement channel near the second sound inlet is denoted as S2, and the area of the first sound inlet of the receiving groove of the mounting frame is denoted as S. Among them, (S1 + S2) / S ≥ 0.18. Since the windproof sound-permeable member is provided in the sound propagation channel, it will have an adverse effect on sound propagation, that is, a part of the sound pressure will be lost. According to the sound propagation principle L w = L1 + 10lgS (L W is the sound power, L1 is the sound pressure, and S is the area of the sound inlet), it can be seen that when the sound pressure L1 is lost, as a compensation, the total area (that is, S1 + S2) at the second sound inlet can be increased to maintain the sound power collected by the sound collection element. Therefore, the ratio of the total area (that is, S1 + S2) of the second sound inlet of the sound collection channel to the area S of the first sound inlet at the front part of the receiving groove is limited within a reasonable value range: (S1 + S2) / S ≥ 0.18, which can ensure that enough noise can pass through the sound collection channel of the protection device, compensate for the sound pressure lost due to the setting of the windproof sound-permeable member, and further ensure that the sound can meet the sound pressure requirements of the sound collection element when it propagates into the receiving groove, further improving the accuracy of noise collection.

[0020] For another improvement, the area of the cross-section of the windproof sound-permeable member near the second sound inlet is denoted as S1, the area of the cross-section of the sound supplement channel near the second sound inlet is denoted as S2, the dimension of the part of the windproof sound-permeable member near the second sound inlet in the front-rear direction is denoted as e, and the dimension of the main body of the windproof sound-permeable member in the up-down direction is denoted as g. 0.5e + 0.5g and e + 0.5g represent the sound propagation path lengths in the windproof sound-permeable member. When the propagation path is longer, the sound loss is more. According to the sound propagation principle L w = L1 + 10lgS, (L W(where \(P\) is the sound power, \(L_1\) is the sound pressure, and \(S\) is the area at the sound inlet), it can be known that due to sound loss, the sound pressure decreases during sound propagation. As a compensation, \(S\) should be increased at this time to ensure that enough sound is collected by the sound collection element. Therefore, considering sound propagation loss and compensation, the value range of the above parameters satisfies the following conditions:

[0021] The present utility model improves the accuracy of sound collection by adding a sound supplement channel. The sound propagation path can be roughly divided into a first path that enters the accommodation groove from the area where the windproof sound-permeable member is located from top to bottom and a second path that enters the accommodation groove through the sound supplement channel and horizontally through the windproof sound-permeable member. Although the addition of the sound supplement channel can compensate for the influence of the windproof sound-permeable member on sound propagation loss, thereby improving the accuracy of noise collection, the selected size of the sound supplement channel also needs to be reasonably configured with the size of the windproof sound-permeable member. If the size of the sound supplement channel is too large, the windproof effect of the windproof sound-permeable member will also be weakened. That is, the best windproof effect and the accuracy of original noise collection can be achieved by adjusting the sizes of the above two. To ensure the windproof effect of the windproof sound-permeable member, most of the noise should enter the cavity where the sound collection element is located from the first path, then At the same time, to ensure that the sound supplement channel plays a certain compensatory role in weakening the sound of the windproof sound-permeable member, then

[0022] Since the sound collection channel of the noise in the protection device includes two sections in the up-down direction and the front-back direction, and at the turning position where the two are combined, a protective sleeve with a certain extension length is also required for protection to ensure that the sound collection element is not affected by the pulsating air pressure in all directions at the first sound inlet of the mounting bracket. Specifically, the windproof sound-permeable member includes an extension section extending upward from the top edge of the first sound inlet of the accommodation groove, and the length of the extension section of the windproof sound-permeable member is denoted as \(h\), and the size of the first sound inlet of the accommodation groove in the up-down direction is \(m\). Among them, the value range of \(h / m\) is: \(0.125\leq h / m\leq0.6\).

[0023] Since the sound collection channel has a vertical section extending vertically and a horizontal section extending forward and backward, that is, there is a turning part at the first sound inlet of the accommodation groove. If the extension length of the outer peripheral edge part of the windproof sound-transmitting member relative to the edge of the first sound inlet of the accommodation groove is too short (such as h / m less than 0.125), it will also be affected by relatively large wind noise. After the above parameter design, the windproof effect of the windproof sound-transmitting member is effectively guaranteed, and the influence on the accuracy of sound collection caused by the too short extension length of the outer peripheral edge of the windproof sound-transmitting member is avoided. Of course, considering the adverse effect of the windproof sound-transmitting member on sound attenuation, the length dimension of the extension section of the windproof sound-transmitting member should not be too large. If h / m is greater than 0.6, it will cause the sound not to effectively meet the sound pressure requirements of the sound collection element when propagating to the accommodation groove, reducing the accuracy of noise collection.

[0024] As an improvement, the windproof sound-transmitting member includes an extension section extending upward from the top edge of the second sound inlet of the accommodation groove, and the length of the extension section of the windproof sound-transmitting member is denoted as h. The distance between the part of the windproof cover in front of the windproof sound-transmitting member and the windproof sound-transmitting member in the front-back direction is denoted as c. Among them, the value range of h / c is: 2 to 6. The size of the extension section h of the above windproof sound-transmitting member reflects to a certain extent the degree of sound propagation attenuation and the windproof effect of the windproof sound-transmitting member. For example, the larger the extension section h of the windproof sound-transmitting member, the greater the degree of sound propagation attenuation, but the better the windproof effect. For example, the smaller the extension section h of the windproof sound-transmitting member, the smaller the degree of sound propagation attenuation, but the windproof effect is also relatively weakened. At the same time, the distance c between the part of the windproof cover in front of the windproof sound-transmitting member and the windproof sound-transmitting member in the front-back direction can play a compensating role in the sound attenuation of the windproof sound-transmitting member to a certain extent. Therefore, the amount of noise lost in the extension section of the windproof sound-transmitting member can be compensated by increasing the length of the distance c. Among them, the value range of h / c needs to be reasonably designed and can be selected as: 2 ≤ h / c ≤ 6.

[0025] In order to further improve the anti-oil effect and prevent the sound collection element from being contaminated by oil, an oil-proof sound-transmitting film is also provided in the accommodation groove to block the front side of the sound collection element. There is a fourth distance between the oil-proof sound-transmitting film and the sound collection element, and this fourth distance is denoted as f. Among them, the value range of f is: f ≥ 2mm.

[0026] In order to ensure the anti-oil performance of the oil-proof sound-transmitting film and enable it to effectively transmit sound waves, the oil-proof sound-transmitting film is a polyethylene film.

[0027] In order to prevent the oil-proof sound-transmitting film from contacting the windproof sound-transmitting member and affecting the sound transmission effect here, the oil-proof sound-transmitting film and the main body of the windproof sound-transmitting member have a sixth distance in the front-back direction.

[0028] To facilitate the installation of the oil-proof sound-transmitting film, an annular step portion is formed on the side wall of the accommodation groove, and the oil-proof sound-transmitting film is disposed on the annular step portion.

[0029] The technical solution adopted by the present utility model to solve the second technical problem is: an oil fume extractor, including an air duct for flue gas to pass through and a sound collection device disposed in the air duct, and the sound collection device adopts the above-mentioned sound collection device.

[0030] As an improvement, the sound collection element is a microphone.

[0031] Compared with the prior art, the advantages of the present utility model are:

[0032] First of all, placing the sound collection element into the first channel section of the sound collection device can effectively isolate the interference of external airflow on the sound collection element and prevent the oil stains in the airflow from contaminating the sound collection element. The wind-proof sound-transmitting member provided in the second channel section can prevent the oil stains in the airflow from contaminating the sound collection element, especially can effectively isolate the wind noise. Even if a small amount of airflow enters the sound collection channel, the pressure pulsation can be weakened in the wind-proof sound-transmitting member, thereby reducing the influence on the sound collection accuracy of the microphone.

[0033] Secondly, the first channel section and the second channel section in the housing are arranged at an angle, so that the entire sound propagation path of the noise in the air duct from the second sound inlet into the second channel section and then to the position of the sound collection element in the first channel section is a turning path. This turning path can prevent too much oil stain from directly passing through the sound propagation channel and contacting the sound collection element, but make most of the oil stains adhere to the side wall of the corresponding channel section or the wind-proof sound-transmitting member, thereby enabling the sound collection element to be as far away from the oil stain as possible and prolonging the service life of the sound collection element. On the other hand, the sound propagation path in the sound collection device adopts a turning path design, which has a weakening effect on high-frequency sounds (such as the high-frequency sound part in wind noise and the high-frequency sound components generated by the fan system, etc., non-target noises), and has little influence on low-frequency sounds. Therefore, it can be better applied to the propagation of low-frequency noises in the sound collection device, which is beneficial for the sound collection element to accurately collect them. The main reason is that the wavelength of low-frequency noises is longer, and it can better adapt to the bending and irregular shapes of the pipeline. When low-frequency noises propagate in a curved pipeline, due to their longer wavelengths, they are not easily blocked and reflected by the pipeline, so they can better propagate and spread. While the wavelength of high-frequency noises is shorter, and they are easily reflected and absorbed by the shape and bending of the pipeline, so it is more difficult to propagate and spread in the pipeline compared with low-frequency noises.

[0034] Furthermore, since the windproof sound-permeable member is provided in the second channel section and the sound propagation path is a turning path, it will have an adverse effect on sound propagation, that is, a part of the sound pressure will be lost. According to the sound propagation principle L w = L1 + 10lgS (where L W is the sound power, L1 is the sound pressure, and S is the area at the sound inlet). When the sound pressure L1 is lost, as a compensation, a sound replenishment channel extending along the second channel section is reserved between the inner wall of the second channel section and the windproof sound-permeable member. This sound replenishment channel can ensure that sufficient noise can pass through the sound propagation channel of the sound collection device to compensate for the sound pressure lost due to the setting of the windproof sound-permeable member, thereby ensuring that the sound can meet the sound pressure requirements of the sound collection element when it propagates to the position where the sound collection element is located, and further improving the accuracy of noise collection.

[0035] Finally, in the preferred embodiment, considering that the noise in the air duct (mainly from the fan system) propagates along the extension direction of the air duct and the propagation direction is opposite to the air flow direction in the air duct, therefore, the sound collection channel is arranged along the extension direction of the air duct, and the second sound inlet of the sound collection channel faces the sound source, so as to directly receive the noise in the air duct. On the other hand, considering that a windproof sound-permeable member with a sufficient length needs to be set on the sound propagation path to prevent wind noise and reduce the influence of the air duct air flow on sound collection, in the present invention, the sound collection channel is arranged in the extension direction of the air duct, so that the size of the entire protection device in the direction perpendicular to the extension direction of the air duct can be made smaller, that is, it occupies less space in the air duct of the range hood, and thus the air resistance at the position of the protection device in the air duct is smaller, so it will not affect the stability of the air flow in the air duct, and at the same time, it also reduces the generation of wind noise to a certain extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is a three-dimensional structural diagram of the protection device according to an embodiment of the present invention;

[0037] Figure 2 is an exploded view of the protection device according to an embodiment of the present invention;

[0038] Figure 3 is a vertical cross-sectional view of the protection device according to an embodiment of the present invention;

[0039] Figure 4 is Figure 3 a structural diagram after removing the windproof sound-permeable member;

[0040] Figure 5 is a cross-sectional view of the protection device cut along the Figure 3 A-A direction in

[0041] Figure 6Schematic three-dimensional structure diagram of the protection device according to an embodiment of the present utility model installed in an air duct;

[0042] Figure 7 is Figure 6 Transverse cross-sectional view taken along the front-rear direction;

[0043] Figure 8 Schematic diagram of the sound propagation process at the first sound inlet of the mounting bracket. Detailed implementation manners

[0044] The present utility model will be further described in detail below in conjunction with the embodiments with reference to the drawings.

[0045] In the description and claims of the present utility model, terms indicating directions such as "front", "rear", "upper", "lower", "left", "right", "side", "top", "bottom", etc. are used to describe various exemplary structural parts and elements of the present utility model. However, these terms are used here only for the purpose of convenience of description and are determined based on the exemplary orientations shown in the drawings. Since the embodiments disclosed by the present utility model can be arranged in different directions, these terms indicating directions are only for illustration and should not be regarded as limitations. For example, "upper" and "lower" are not necessarily limited to the directions opposite to or consistent with the direction of gravity.

[0046] Figures 1-7 A preferred embodiment of the sound collection device and the range hood of the present utility model is shown.

[0047] The sound collection device includes a sound collection element 11 and a housing 2. A sound propagation channel is defined on the housing 2. Among them, the sound propagation channel includes a first channel section and a second channel section connected in sequence. Among them, the sound collection element 11 is located in the first channel section. The first channel section has a first sound inlet 211 communicating with the second channel section. The second channel section has a second sound inlet 45 for external sound to enter therein. The extension line of the opening direction of the first sound inlet 211 intersects with the extension line of the opening direction of the second sound inlet 45. In a preferred embodiment, both the first channel section and the second channel section are straight-line channels. Among them, the extension line of the first channel section intersects with the extension line of the second channel section. The extension line of the first channel section can be understood as the connection line between the position where the sound inlet of this channel section is located and the position where the sound collection element 11 is located. The extension line of the second channel section can be understood as the connection line between the position where the sound inlet of this channel section is located and the position where the sound outlet is located.

[0048] The active noise reduction system is usually arranged in the air duct 10 of an oil fume extraction device (such as a range hood or an integrated stove with an oil fume extraction function, etc., kitchen appliances), and the sound collection device is an important part of the active noise reduction system and is also correspondingly arranged in the air duct 10 of the oil fume extraction device. Taking a range hood as an example, the above-mentioned "air duct" can refer to the housing of the range hood or a box structure with a "channel" for the oil fume to pass through alone, such as the channel between the fan system and the smoke collecting hood of a ceiling-mounted range hood. The active noise reduction system generally includes a sound collection element 11 (microphone) and a speaker, that is, the noise generated when the range hood works is collected by the microphone, and the collected noise sound wave is transmitted to the controller in the form of an electrical signal. After being analyzed and processed by the controller, an instruction is sent to the speaker to control the speaker to emit a sound wave matching the noise sound wave to neutralize the noise sound wave, thereby achieving the noise reduction effect. The sound collection device of this embodiment can be used to install the above-mentioned sound collection element 11 and provide protection against oil and wind.

[0049] The sound collection device is located below the fan system, that is, the noise generated by the fan system propagates downward along the air duct 10, and the sound collection device is just arranged on the downward propagation path in the air duct 10. In addition to the housing, the sound collection device also includes an oil-proof sound-transmitting membrane 28 and a wind-proof sound-transmitting member 30. The housing includes a mounting bracket 20 and a wind-proof cover 40.

[0050] In this embodiment, taking the box structure 1 with a "channel" for the oil fume to pass through alone as an example, the installation structure of the sound collection device is described. The channel in the box 1 serves as the air duct 10. The mounting bracket 20 can be installed on the rear side wall of the air duct 10, and a receiving groove 21 is provided on its front side wall. The sound collection element 11 is placed in the receiving groove 21, and this receiving groove constitutes the first channel section of the above-mentioned housing 2. The front part of the receiving groove 21 has an opening as the first sound inlet 211 for sound to enter the receiving groove 21. Among them, the first sound inlet 211 should be understood as an opening through which the sound from the outside (the sound collection channel in this embodiment) can effectively enter the receiving groove 21, such as Figure 8 the opening defined by the boundary points A1, A2, etc. of the receiving groove 21 in the circumferential direction, rather than the largest open mouth at the front part of the receiving groove 21. In the state where the mounting bracket 20 is installed in place on the rear side wall of the air duct 10, the rear wall of the part of the mounting bracket 20 where the receiving groove 21 is located is in contact with the side wall of the air duct 10.

[0051] The mounting bracket 20 further has a third mounting portion 263 extending respectively to the left and right sides and exposing outside the wind shield 40, and a fourth mounting portion 264 extending downward at the bottom of the mounting bracket 20 and exposing outside the wind shield 40. Both the third mounting portion 263 and the fourth mounting portion 264 are connected to the side wall of the air duct 10 or the cross beam inside the air duct 10 by screws. At the lower region of the receiving groove 21 of the mounting bracket 20, there is a connecting post 265 extending forward. The wind shield 40 can be connected to the connecting post 265 of the mounting bracket 20 by screws 50.

[0052] The wind shield 40 includes a first side wall 411 and a second side wall 412 that are opposite to each other left and right and arranged at intervals, and a third side wall 413 connected between the front side edges of the first side wall 411 and the second side wall 412. The third side wall 413 of the wind shield 40 is located on the front side of the receiving groove 21 of the mounting bracket 20. On the third side wall 413 of the wind shield 40, there is a guiding surface 4130 that gradually inclines towards the inside of the air duct 10 along the air flow direction in the air duct 10 (as shown by the hollow arrow in Figure 3 ). Specifically, the guiding surface 4130 is located at the lower part of the third side wall 413, that is, at the windward end of the third side wall 413. It inclines forward from bottom to top, while the upper part of the third side wall 413 is basically vertically extended and is opposite to the part where the receiving groove 21 of the mounting bracket 20 is located in the front-rear direction. Along the air flow direction in the air duct 10, the position where the guiding surface 4130 of the wind shield 40 is located is upstream of the position where the receiving groove 21 of the mounting bracket 20 is located. Arranging the guiding surface 4130 of the wind shield 40 at a lower position also makes there be enough space at the position inside the wind shield 40 opposite to the front part of the receiving groove 21 to arrange components such as the wind-proof and sound-transmitting member 30 and the oil-proof and sound-transmitting film 28. In addition, considering that if the inclination angle of the guiding surface 4130 towards the inside of the air duct 10 is too large, it will also affect the air flow in the air duct 10 to a certain extent, such as affecting the air volume flowing in the air duct 10 or generating additional noise problems. Therefore, the inclination angle of the guiding surface 4130 of the wind shield 40 needs to be reasonably designed. The included angle formed between the guiding surface 4130 of the wind shield 40 and the side wall of the air duct 10 for mounting the wind shield 40 is denoted as A, and the value range of A is: A ≤ 60°. In order to reduce the influence of the installation of the protection device on the flow field in the air duct 10, the dimension of the air duct 10 in the front-rear direction in this embodiment is denoted as a, and the distance that the wind shield 40 protrudes forward relative to the side wall of the air duct 10 for mounting the wind shield 40 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 a turbulence problem for the air flow at the position of the protection device in the air duct 10, generating additional noise and affecting the accuracy of sound collection. Therefore, the value of b / a needs to be reasonably limited. In this embodiment, preferably, b / a ≤ 0.35, as shown in detail in Figure 7。

[0053] To improve the anti-oil pollution effect, the wind shield 40 of this embodiment can be made of plastic or metal parts.

[0054] In this embodiment, a gap channel extending vertically in the front-rear direction is formed between the front side surface of the wind shield 40 and the mounting frame 20. The upper end of this gap channel (i.e., the end close to the noise source) is open, and the lower end (i.e., the end far from the noise source) is closed, which is the sound collection channel 200. This sound collection channel 200 is located on the front side of the mounting frame 20, that is, it constitutes the second channel section of the above-mentioned housing 2. More specifically, a second sound inlet 45 communicating with the above-mentioned sound collection channel 200 is defined between the end of the wind shield 40 facing away from the wind (i.e., a section along the extension direction of the air duct, close to the fan system of the range hood). The lower section of the sound collection channel 200 is opposite to the first sound inlet 211 at the front part of the accommodation groove 21 of the mounting frame 20 in the front-rear direction. The air duct 10 and the sound collection channel 200 of this embodiment both extend vertically, that is, the extension direction of the sound collection channel 200 is the same as the extension direction B2 of the air duct 10. The opening direction B1 of the first sound inlet 211 intersects with the extension direction of the sound collection channel 200 to form a first included angle M. The value range of this first included angle M is: 5° ≤ M ≤ 180°. Considering that if the included angle formed between the opening direction B1 of the first sound inlet 211 and the extension direction of the sound collection channel 200 is too small, the oil liquid will still enter the accommodation groove 21 through the first sound inlet 211 to contaminate the sound collection element 11. If the included angle formed between the opening direction 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 turns too much, which will have an adverse effect on sound propagation, that is, a part of the sound pressure will be lost, which is not conducive to the accurate collection of noise by the sound collection element. Therefore, the included angle formed between the opening direction of the first sound inlet 211 and the extension direction B3 of the sound collection channel 200 also needs to be reasonably designed. Preferably, the value of the first included angle M is 90°. In addition, the opening direction B4 of the second sound inlet 45 of this embodiment faces upward, that is, the opening direction of the second sound inlet 45 is also perpendicular to the opening direction B1 of the first sound inlet 211.

[0055] After the wind shield 40 is installed, it can effectively prevent the high-speed oil fume airflow from directly impacting the windproof sound-transmitting member 30, greatly reducing the pollution of the oil fume to the windproof sound-transmitting member 30. At the same time, after the wind shield 40 is combined with the mounting frame 20, only the upper second sound inlet 45 is retained, directly isolating the lower airflow noise and the noise interference of the secondary turbulence, so that the noise entering the windproof sound-transmitting member 30 mainly comes from above, that is, the main noise source direction of the range hood, thus ensuring the accuracy of noise collection.

[0056] In this embodiment, the main body of the windproof sound transmission member 30 is smaller than the sound collection channel 200 in the front-rear direction, and a gap channel is formed between the third side wall 413 of the windproof cover 40 and the windproof sound transmission member 30. This gap channel serves as a sound supplement channel 450, which is connected to the upper second sound inlet 45. It can effectively compensate for the sound pressure loss caused by the setting of the windproof sound transmission member 30, thereby ensuring that the sound pressure requirement of the sound collection element 11 is met when the sound propagates to the second sound inlet 45, and further improving the accuracy of noise collection. In a preferred solution, in order to achieve the protective effect of the windproof cover 40 on the windproof sound transmission member 30 and minimize the contact between the windproof sound transmission member 30 and the flue gas in the air duct, an extension wall 46 extends upward from the upper edge of the windproof cover 40 relative to the top surface of the windproof sound transmission member 30, that is, the top edge of the extension wall 46 is higher than the top surface of the windproof sound transmission member 30. Affected by the airflow in the air duct 10, an airflow vortex is formed at the leeward end of the windproof cover 40 (i.e., at the second sound inlet 45), which will generate obvious wind noise. The setting of the extension wall 46 of the windproof cover 40 can make the airflow vortex as far away from the second sound inlet 45 as possible, avoiding the influence of the airflow vortex on the sound entering the second sound inlet 45.

[0057] Since the sound collection element 11 is installed in the accommodation groove 21 of the mounting bracket 20 and a windproof cover 40 is provided outside the mounting bracket 20, the interference of the airflow in the air duct 10 to the sound collection element 11 can be effectively isolated, and the sound collection element 11 can be prevented from being contaminated by the oil stain in the airflow. At the same time, a windproof and sound-permeable element 30 is provided in the sound collection channel 200, effectively eliminating wind noise. Even if a small amount of airflow enters the sound collection channel 200, the pressure pulsation can be weakened in the windproof and sound-permeable element 30, thereby reducing the impact on the sound collection accuracy of the microphone. In addition, considering that the noise in the air duct 10 (mainly from the fan system) propagates along the extension direction of the air duct 10 and the propagation direction is opposite to the airflow direction in the air duct 10, therefore, arranging the sound collection channel 200 along the extension direction of the air duct can make the second sound inlet 45 of the sound collection channel 200 face the sound source, so as to directly receive the noise. On the other hand, considering that a windproof and sound-permeable element 30 with a sufficient length needs to be provided on the sound propagation path to prevent wind noise, thereby reducing the influence of the airflow in the air duct 10 on sound collection. In this embodiment, the sound collection channel 200 for placing the windproof and sound-permeable element 30 is arranged in the extension direction of the air duct 10, and the sound propagation path has a turning design, so the size of the entire protection device in the direction perpendicular to the extension direction of the air duct can be made smaller, that is, it occupies less space in the air duct 10 of the range hood, and further makes the wind resistance at the position of the protection device in the air duct 10 smaller. Therefore, it will not affect the stability of the airflow in the air duct and also reduces the generation of wind noise to a certain extent. On this basis, considering that the environment of the range hood air duct 10 is full of oil stains, if the orientation of the first sound inlet 211 is consistent with the extension direction of the sound collection channel, then the sound collection element 11 is easily contaminated by the oil stains flowing down along the air duct 10. Therefore, this embodiment adopts the structural design that the sound collection channel 200 is located on the front side of the accommodation groove 21, that is, the opening orientation B1 of the first sound inlet 211 of the accommodation groove 21 has a certain angle with the extension direction of the sound collection channel. This makes the path for the noise in the air duct 10 to propagate from the second sound inlet 45 to the position of the sound collection element 11 in the accommodation groove 21 a turning path. This turning path can prevent too much oil stain from directly passing through the sound collection channel 200 and contacting the sound collection element 11, but makes most of the oil stains adhere to the side wall of the sound collection channel 200 or the windproof and sound-permeable element 30, thereby enabling the sound collection element 11 to be as far away from the oil stain as possible and extending the service life of the sound collection element 11.Considering that the target noise to be collected by the active noise cancellation system (mainly from the fan system) is low-frequency noise, the sound propagation path inside the protection device adopts a turning path design, which has a weakening effect on high-frequency sounds (such as the high-frequency sound components in wind noise and the high-frequency sound components generated by the fan system, etc., which are non-target noises), and has little impact on low-frequency sounds. Therefore, it can be better applied to the propagation of low-frequency noise inside the protection device, which is beneficial for the sound collection element 11 to accurately collect it. The main reason is that the wavelength of low-frequency noise is longer, and it can better adapt to the bending and irregular shapes of the pipeline. When low-frequency noise propagates in a bent pipeline, due to its longer wavelength, it is not easily blocked and reflected by the pipeline, so it can better propagate and spread. While the wavelength of high-frequency noise is shorter, it is easily reflected and absorbed by the shape and bending of the pipeline, so it is more difficult to propagate and spread in the pipeline compared to low-frequency noise.

[0058] The oil-proof sound-transmitting membrane 28 covers the first sound inlet 211 of the receiving groove 21 of the mounting frame 20, specifically, it is installed at the position of the front open edge of the receiving groove 21 of the mounting frame 20. More specifically, in order to facilitate the installation of the oil-proof sound-transmitting membrane 28, an annular step portion 210 is formed at the edge position of the first sound inlet 211 of the receiving groove 21, and the oil-proof sound-transmitting membrane 28 is arranged on the annular step portion 210. In order to ensure the oil-proof performance of the oil-proof sound-transmitting membrane 28 and enable it to effectively transmit sound waves, the oil-proof sound-transmitting membrane 28 of this embodiment is preferably a polyethylene film. Among them, there is a fourth distance between the oil-proof sound-transmitting membrane 28 and the sound collection element 11, which is denoted as f. Among them, the value range of f is: f≥2mm. Thus, it is avoided that the film vibrates or undergoes micro-deformation and contacts the sound collection element 11, resulting in sound propagation variation and affecting the accuracy of sound collection. It can be understood that the above-mentioned fourth distance f between the oil-proof sound-transmitting membrane 28 and the sound collection element 11 should refer to the distance between the oil-proof sound-transmitting membrane 28 and the microphone chip on the sound collection element 28, that is, the oil-proof sound-transmitting membrane 28 can have partial contact with other components (such as solder joints or fixing screws, etc.) on the circuit board where the microphone chip is located. The wind-proof sound-transmitting member 30 does not directly contact the oil-proof sound-transmitting membrane 28 to ensure the oil-proof effect. Specifically, there is a sixth distance between the oil-proof sound-transmitting membrane 28 and the main body of the wind-proof sound-transmitting member 30 in the front-rear direction, which is denoted as n. In order to avoid the oil-proof sound-transmitting membrane 28 contacting the wind-proof sound-transmitting member 30 and affecting the sound transmission effect here, the sixth distance n between the oil-proof sound-transmitting membrane 28 and the wind-proof sound-transmitting member 30 should be greater than 0.1mm, and the preferred range is 0.5mm - 3mm.

[0059] In order to effectively slow down the airflow and eliminate the airflow impact, the windproof sound-permeable member 30 is a sleeve member made of a porous sound-absorbing material. For example, the windproof sound-permeable member 30 can be made of polyurethane foam, melamine foam sponge, etc. Among them, the porosity of the windproof sound-permeable member 30 is greater than 70%. The windproof sound-permeable member 30 can not only prevent the airflow from impacting the oil-proof sound-permeable film 28 and generating additional noise, but also the property of its porous material itself can absorb the high-frequency components in the sound energy, realizing the filtering function of filtering the noise signal.

[0060] The windproof sound-permeable member 30 of this embodiment includes an extension section 301 extending upward from the top edge of the first sound inlet 211 of the accommodation groove 21. The length of the extension section 301 of the windproof sound-permeable member 30 is denoted as h, and the size of the first sound inlet 211 of the accommodation groove 21 in the up-down direction is m. Among them, the value range of h / m is: 0.125 ≤ h / m ≤ 0.6. Since the sound collection channel has a vertical section extending vertically and a horizontal section extending in the front-back direction, that is, there is a turning part at the first sound inlet 211 of the accommodation groove 21. If the extension length of the outer peripheral edge part of the windproof sound-permeable member 30 relative to the edge of the first sound inlet 211 of the accommodation groove 21 is too short (such as h / m is less than 0.125), it will also be affected by relatively large wind noise. After the above parameter design, the windproof effect of the windproof sound-permeable member is effectively guaranteed, and the accuracy of sound collection is prevented from being affected due to the too short extension length of the outer peripheral edge of the windproof sound-permeable member. Of course, considering the adverse effect of the windproof sound-permeable member 30 on sound attenuation, the length dimension of the extension section 301 of the windproof sound-permeable member 30 should not be too large. If h / m is greater than 0.6, it will cause the sound not to effectively meet the sound pressure requirements of the sound collection element 11 when propagating to the accommodation groove 21, reducing the accuracy of noise collection.

[0061] The distance between the part of the windproof cover 40 located in front of the windproof sound-permeable member 30 and the windproof sound-permeable member 300 in the front-back direction, that is, the size of the sound supplement channel in the front-back direction is denoted as c. Since the size of the extension section 301 of the above-mentioned windproof sound-permeable member 30 reflects to a certain extent the degree of sound propagation attenuation and the windproof effect of the windproof sound-permeable member 30. For example, the larger the extension section h of the windproof sound-permeable member 30, the greater the degree of sound propagation attenuation, but the better the windproof effect. For example, the smaller the extension section h of the windproof sound-permeable member 30, the smaller the degree of sound propagation attenuation, but the relatively weaker the windproof effect. At the same time, the distance c between the part of the windproof cover 40 located in front of the windproof sound-permeable member 30 and the windproof sound-permeable member 30 in the front-back direction can also play a compensating role in the sound attenuation of the windproof sound-permeable member 30 to a certain extent. Therefore, the amount of noise lost in the extension section 301 of the windproof sound-permeable member 30 can be compensated by increasing the length of the distance c. Therefore, the value range of h / c needs to be reasonably designed and can be selected as: 2 ≤ h / c ≤ 6.

[0062] To prevent the windproof sound-permeable member 30 from contacting the oil flowing continuously on the side wall of the air duct 10, after being installed on the mounting bracket 20, there is a first distance between the windproof sound-permeable member 30 and the rear side wall of the air duct 10, and this first distance is denoted as d. Among them, the value range of d is: d≥4mm. Similarly, to ensure the windproof effect, the dimension (i.e., thickness) of the main body of the windproof sound-permeable member 30 in the front-rear direction is denoted as e. Among them, the value range of e is: 40mm≥e≥3mm. Specifically, when e≥3mm, it can ensure that the windproof sound-permeable member 30 effectively prevents the airflow in the air duct from directly impacting the sound collection element 11, that is, it has a good windproof effect. Of course, considering that the windproof ball 30 (generally made of porous material that can prevent airflow disturbance and is sound-permeable) itself will have an adverse effect on weakening the sound, so the dimension (i.e., thickness) of the windproof sound-permeable member 30 in the front-rear direction cannot be too large, and e≤40mm is required. At the same time, when the dimension (i.e., thickness) of the windproof sound-permeable member 30 in the front-rear direction is fixed, the dimension d1 of the main body of the windproof sound-permeable member 30 in the left-right direction also needs to be adapted to it, that is, it is necessary to reasonably limit e / d1. Specifically, if e / d1 is too small (such as e / d1<0.2), it means that the dimension of the main body of the windproof sound-permeable member 30 in the left-right direction is relatively large, and the area of its upper part in contact with the oil stain increases, which will directly affect the service life of the windproof sound-permeable member 30. If e / d1 is too large (such as e / d1>0.5), it means that the dimension of the main body of the windproof sound-permeable member 30 in the left-right direction is relatively small, which is not conducive to the sound being transmitted into the sound collection channel from a large angle range in the horizontal direction above, affecting the accuracy of sound collection.

[0063] The dimension c of the sound compensation channel 450 in the front-rear direction, its value range can be: 0.5mm≤c≤2mm. The dimension of the main body of the windproof sound-permeable member 30 in the front-rear direction is e, and the ratio c / e between the two needs to be reasonably limited. If the value of c / e is too small (such as less than 0.1), it means that the dimension of the sound compensation channel is relatively small. Although it can suppress the wind noise, the sound compensation effect is limited and is not sufficient to compensate for the sound pressure loss caused by the setting of the windproof sound-permeable member. If the value of c / e is too large (such as greater than 0.45), it means that the dimension of the sound compensation channel is relatively large. Although it meets the purpose of compensating for the sound pressure loss caused by the setting of the windproof sound-permeable member, it also means that the windproof effect of the windproof sound-permeable member will be weakened, resulting in a certain degree of damage to the audio signal of the target noise to be collected by the wind noise. Therefore, in this embodiment, the ratio c / e of the dimension c of the sound compensation channel 450 in the front-rear direction to the dimension of the main body of the windproof sound-permeable member 30 in the front-rear direction preferably has a value range of: 0.1≤c / e≤0.45.

[0064] Due to the arrangement of the windproof sound-permeable member 30 in the sound collection channel, there will be a certain loss in the propagation path of the sound from the second sound inlet 45 to the location of the sound collection element 11, that is, a part of the sound pressure will be lost. Therefore, it is necessary to ensure that a sufficient amount of noise to be collected enters the receiving slot 21 of the mounting frame 20 to be received by the sound collection element 11 and achieve the purpose of accurately collecting noise signals. Specifically, the principles of sound attenuation and compensation are as follows:

[0065] L w =L1-ΔL+10lgS0

[0066] The noise energy that the sound collection component can collect per unit time is the sound power L w ;

[0067] When the sound is transmitted to the top surface of the windproof and sound-permeable member 30, the sound pressure is L1;

[0068] Due to the weakening effect of the windproof sound-permeable member 30, the sound pressure of the loss noise is ΔL;

[0069] An area S0 of a cross section at the second sound inlet 45 of the sound collecting channel;

[0070] Therefore, if the sound is seriously weakened because the thickness of the windproof sound-permeable member 30 or the length dimension on the sound propagation path is too large, the sound power L collected by the sound collecting element can be guaranteed by increasing S0. w Specifically, the cross-sectional area of ​​the windproof sound-permeable member 30 of this embodiment near the second sound inlet 45 is recorded as S1, and the cross-sectional area of ​​the sound supplement channel 450 near the second sound inlet 45 is recorded as S2. Then the total cross-sectional area of ​​the second sound inlet 45 of the sound collection channel is (S1+S2). Figure 3 The cross section cut along the S3-S3 direction is the cross section of the main body of the windproof sound-permeable component 30 adjacent to the second sound inlet 45 and the cross section of the sound supplement channel 450 adjacent to the second sound inlet 45. The area of ​​the first sound inlet 211 of the receiving slot 21 of the mounting frame 20 is denoted as S. The value of the ratio between the total area (S1+S2) of the cross section at the second sound inlet 45 of the sound collection channel and the opening area S at the first sound inlet 211 at the front of the receiving slot 21 needs to be reasonably limited: (S1+S2) / S≥0.18, thereby ensuring that enough noise can pass through the sound collection channel of the protective device to compensate for the sound pressure loss caused by the setting of the windproof sound-permeable component, thereby ensuring that the sound can meet the sound pressure requirement of the sound collection element 11 when propagating to the second sound inlet 45, further improving the accuracy of noise collection.

[0071] On the other hand, the dimension of the main body of the windproof sound transmission member 30 in the up-down direction in this embodiment is denoted as g. In order to adapt to the dimension of the first sound inlet 211 at the front part of the accommodation groove 21 and ensure the windproof effect, the value of g needs to satisfy the condition: 100 mm ≥ g ≥ 10 mm.

[0072] This embodiment considers increasing the sound supplement channel 450 to improve the accuracy of sound collection. The sound propagation path in the sound collection channel can be roughly divided into a first path that enters the accommodation groove 21 from top to bottom through the area where the windproof sound transmission member 30 is located and a second path that enters the accommodation groove 21 through the sound supplement channel 450 and horizontally through the windproof sound transmission member 30. Although the addition of the sound supplement channel can reduce the obstruction of sound, thereby improving the accuracy of noise collection, the selected dimension of the sound supplement channel 450 also needs to be reasonably configured with the dimension of the windproof sound transmission member 30. If the dimension of the sound supplement channel is too large, the windproof effect of the windproof sound transmission member will also be weakened. Therefore, the best windproof effect and the accuracy of original noise collection can be achieved by adjusting the dimensions of the above two. To ensure the windproof effect of the windproof sound transmission member, most of the noise should enter the cavity where the sound collection element is located from the first path, so At the same time, to ensure that the sound supplement channel plays a certain compensatory role in weakening the sound of the windproof sound transmission member, it is required that Therefore, after comprehensive consideration, the value ranges of the above parameters satisfy the following conditions:

[0073] After installing the sound collection element 11 in the accommodation groove 21 of the mounting frame 20 in this embodiment, an oil-proof sound transmission film 28 is provided at the first sound inlet 211, a windproof sound transmission member 30 is provided outside it, and a windproof cover 40 is provided outside the windproof sound transmission member 30. This kind of protection device adopts the above three-layer protection to effectively eliminate wind noise and achieve the purpose of preventing oil pollution. Moreover, a sound supplement channel communicating with the second sound inlet is reserved between the part of the windproof cover located in front of the windproof sound transmission member and the windproof sound transmission member, so that the influence of the sound propagation obstruction is reduced as much as possible, and the accuracy of noise collection is further improved. In the preferred solution, after the windproof cover 40 covers the windproof sound transmission member 30, a second sound inlet 45 communicating with the outside is reserved at the leeward end. According to the air flow law, the flow in the area of the windproof sound transmission member 30 adjacent to the second sound inlet 45 is a low-speed and high-static-pressure area, which also effectively reduces the oil fume adhesion on the windproof sound transmission member 30. On the other hand, it also enables noise to be effectively transmitted to the accommodation groove 21 of the mounting frame 20 through the second sound inlet 45, further ensuring the accuracy of noise data collection.

[0074] This embodiment also relates to a range hood, which includes an air duct 10 for flue gas to pass through and an active noise reduction system disposed in the air duct 10, and the active noise reduction system includes the above-mentioned sound collection device.

Claims

1. A sound collection device, comprising a sound collection element (11), characterized in that: It further includes a housing (2) on which a sound propagation channel is defined. The sound propagation channel includes a first channel section and a second channel section that are sequentially connected and arranged at an angle. The sound collection element (11) is located in the first channel section. The second channel section has a second sound inlet (45) for external sound to enter therein. A windproof and sound-permeable member (30) is further provided in the second channel section. A gap channel extending along the second channel section is formed between the windproof and sound-permeable member (30) and the inner wall of the second channel section as a sound supplementary channel (450).

2. The sound collection device according to claim 1, wherein: The above-mentioned sound collection device is disposed in the air duct (10) of the oil fume suction 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 housing (2). 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, wherein: The first channel section has a first sound inlet (211) communicating with the second channel section. The extension line of the opening direction of the first sound inlet (211) is perpendicular to the extension direction of the second channel section.

4. The sound collection device according to claim 2 or 3, characterized in that: The housing (2) includes a mounting frame (20) and a windproof cover (40). A receiving groove (21) is formed on the front side wall of the mounting frame (20). The sound collection element (11) is placed in the receiving groove (21). The receiving groove (21) constitutes the first channel section. The windproof cover (40) covers outside the mounting frame (20), and a sound collection channel (200) communicating with the receiving groove (21) and located in front of the receiving groove (21) is defined between the windproof cover (40) and the mounting frame (20). The sound collection channel (200) constitutes the second channel section. The second sound inlet (45) is defined between the windproof cover (40) and the mounting frame (20) at the leeward end. The sound supplementary channel (450) is reserved between the windproof and sound-permeable member (30) and the windproof cover (40).

5. The sound collection device according to claim 4, characterized in that: Both the sound collection channel (200) and the extension direction of the air duct (10) extend vertically. The opening of the second sound inlet (45) faces upward. The front opening of the receiving groove (21) forms a first sound inlet (211) communicating with the sound collection channel (200). The opening direction (B1) of the first sound inlet (211) is perpendicular to the extension direction of the sound collection channel (200).

6. The sound acquisition device according to claim 4, characterized in that: The distance in the front-rear direction between the part of the windproof cover (40) located in front of the windproof and sound-permeable member (30) and the windproof and sound-permeable member (30) is denoted as c, and the dimension of the main body of the windproof and sound-permeable member (30) in the front-rear direction is denoted as e. Wherein, the value range of c / e is: 0.1 ≤ c / e ≤ 0.

45.

7. The sound collection device according to claim 6, wherein: The value range of the distance between the part of the windproof cover (40) located in front of the windproof and sound-permeable member (30) and the windproof and sound-permeable member (30) is: 0.5 mm ≤ c ≤ 2 mm.

8. The sound collection device according to any one of claims 1 to 3, characterized in that: The windproof and sound-permeable member (30) is a sound-permeable member made of porous sound-absorbing material.

9. The sound collection device according to claim 5, characterized in that: The area of the cross-section of the windproof sound-permeable member (30) adjacent to the second sound inlet (45) is denoted as S1, the area of the cross-section of the sound replenishing channel (450) adjacent to the second sound inlet (45) is denoted as S2, and the area of the first sound inlet (211) of the receiving groove (21) of the mounting bracket (20) is denoted as S. Among them, the value range of (S1 + S2) / S is: (S1 + S2) / S ≥ 0.

18.

10. The sound collection device according to claim 5, characterized in that: The area of the cross-section of the windproof sound-permeable member (30) at a position adjacent to the second sound inlet (45) is denoted as S1, the area of the cross-section of the sound replenishing channel (450) at a position adjacent to the second sound inlet (45) is denoted as S2, and the dimension of the main body of the windproof sound-permeable member (30) in the vertical direction is denoted as g. The value ranges of the above parameters satisfy the following conditions:

11. The sound collection device according to claim 5, characterized in that: The windproof sound-permeable member (30) includes an extension section (301) extending upward from the top edge of the first sound inlet (211) of the receiving groove (21), and the length of the extension section (301) of the windproof sound-permeable member (30) is denoted as h. The distance between the part of the windproof cover (40) located on the front side of the windproof sound-permeable member (30) and the windproof sound-permeable member (30) is denoted as c. Among them, the value range of h / c is: 2 ≤ h / c ≤ 6.

12. An oil fume suction machine, comprising a duct (10) for flue gas to pass through and a sound collection device arranged in the duct (10), characterized in that: The described sound collection device adopts the sound collection device described in any one of claims 1 to 11.

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

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