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 and comprises a first channel section and a second channel section which are sequentially connected and arranged at an included angle, 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 present invention relates to the technical field of range hoods, and particularly 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 that trouble 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 that matches 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 an active noise reduction function. The microphone of this range hood is arranged inside the housing 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, in the prior art, the microphones and speakers used in the active noise reduction system are often arranged inside the air duct of the range hood. However, due to the oil pollution environment of the range hood, the microphones and speakers are often contaminated, resulting in the reduction of the noise reduction effect of the active noise reduction system as the use time increases, and even malfunction. 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 incoming device, a central data processor, and a noise reduction unit. The incoming device includes a microphone, and the microphone is arbitrarily installed at a place of the range hood. The noise reduction unit includes at least two noise reduction boxes, and the noise reduction boxes are arranged at the bottom of the volute of the range hood, facing 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 pollution detection module for the noise reduction device. The oil pollution detection module detects the oil pollution and damage condition 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, thereby ensuring 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, thereby ensuring 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 protective 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 propagation channel is defined on the housing. The sound propagation channel includes a first channel segment and a second channel segment that are connected in sequence and arranged at an angle. The sound collection element is located in the first channel segment. The second channel segment has a second sound inlet for external sound to enter therein. A wind-proof sound-permeable member is further provided in the second channel segment. A gap channel extending along the second channel segment is further provided between the wind-proof sound-permeable member and the inner wall of the second channel segment 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 airflow to the sound collection element and prevent the sound collection element from being contaminated by oil stains in the airflow. The windproof and sound-permeable element set in the second channel section can prevent the sound collection element from being contaminated by oil stains in the airflow, especially can effectively isolate wind noise. Even if a small amount of airflow enters 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 from the second sound inlet into the second channel section 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 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 windproof and sound-permeable element, thereby enabling the sound collection element to be as far away from the oil stain as possible and 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 little impact on low-frequency sounds. Therefore, it can be better applied to the propagation of low-frequency noise in the sound collection device, which is beneficial for the sound collection element 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 and 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 than low-frequency noise. 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 supplement 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 supplement channel can ensure that enough 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 and sound-permeable element, and further ensure 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 within 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 the 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. Furthermore, the air resistance at the location of the collection device in the air duct is 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 adopt an integral structure design, such as a bent pipe structure with an integral design. However, for the convenience of installing components such as the sound collection element, the housing preferably adopts a split structure design assembled together by fasteners. The housing includes an installation frame and a windproof cover. A receiving groove is opened on the front side wall of the installation frame, and the sound collection element is placed in the receiving groove. The receiving groove constitutes the first channel section. The windproof cover covers outside the installation frame 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 installation frame. This sound collection channel constitutes the second channel section. The windproof cover and the installation frame 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 extending direction of the main body of the sound collection channel is consistent with the extending direction of the air duct. Generally speaking, in order 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 consistent with the extending direction of the sound collection channel, that is, the opening direction of the first sound inlet and the extending 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 extending 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 extending 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 extending direction of the sound collection channel is too large, the sound propagation path will turn 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, in order to better avoid the sound collection element from contacting oil stains and improve the windproof effect, the extending 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 extending 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-back 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: 0.5 mm ≤ c ≤ 2 mm.

[0018] For further improvement, the windproof sound-transmitting member is a sound-transmitting member made of a porous sound-absorbing material. Using a sound-transmitting member made of a damping material such as a porous sound-absorbing material as the windproof sound-transmitting 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-transmitting member can be made of polyurethane foam, melamine foam sponge, etc. The windproof sound-transmitting member can not only prevent the airflow from impacting the oil-proof sound-transmitting membrane and generating additional noise, but also absorb the high-frequency components in the sound energy due to its porous material property, realizing the function of filtering the noise signal.

[0019] As an improvement, the area of the cross-section of the windproof sound-transmitting member at a position adjacent to the second sound inlet is denoted as S1, the area of the cross-section of the sound compensation channel at a position adjacent to the second sound inlet is denoted as S2, and the area of the first sound inlet of the receiving groove of the mounting bracket is denoted as S. Among them, (S1 + S2) / S ≥ 0.18. Since the windproof sound-transmitting member is provided in the sound propagation channel, it will have an adverse effect on the 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 (i.e., 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 (i.e., 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 to compensate for the sound pressure lost due to the setting of the windproof sound-transmitting 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-transmitting member at a position adjacent to the second sound inlet is denoted as S1, the area of the cross-section of the sound compensation channel at a position adjacent to the second sound inlet is denoted as S2, the dimension of the part of the windproof sound-transmitting member adjacent to the second sound inlet in the front-rear direction is denoted as e, and the dimension of the main body of the windproof sound-transmitting 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-transmitting 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 of the sound inlet). It can be seen 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 invention 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 loss of sound propagation caused by the windproof sound-permeable member, thereby improving the accuracy of noise collection, the selected size of the sound supplement channel should also 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 two. For example, 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, it is required that

[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, at the turning position where the two are combined, a protective sleeve with a certain extension length is also required to protect it, so as to ensure that the sound collection element is not affected by the pulsating pressure of the air flow in all directions at the first sound inlet of the mounting rack. 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 front and back, that is, there is a turning part at the first sound inlet of the receiving 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 receiving groove 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-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 receiving 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 receiving 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 located 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 relatively weaker the windproof effect. At the same time, the distance c between the part of the windproof cover located in front of the windproof sound-transmitting member and the windproof sound-transmitting member in the front-back direction can play a compensatory 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 oil-proof effect and prevent the sound collection element from being contaminated by oil, an oil-proof sound-transmitting film is also provided in the receiving 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 oil-proof 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 and sound-transmitting film, an annular step portion is formed on the side wall of the accommodating groove, and the oil-proof and sound-transmitting film is disposed on the annular step portion.

[0029] The technical solution adopted by the present invention 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 invention 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 stain in the airflow from contaminating the sound collection element. The wind-proof and sound-transmitting member provided in the second channel section can prevent the oil stain 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 and 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 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 too much oil stain from directly passing through the sound propagation channel and contacting the sound collection element, but make most of the oil stain adhere to the side wall of the corresponding channel section or the wind-proof and 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 the 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 bent pipeline, due to their longer wavelength, they are not easily blocked and reflected by the pipeline, so they can better propagate and diffuse. 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 for them to propagate and diffuse in the pipeline compared with low-frequency noises.

[0034] Furthermore, since a wind-proof and sound-transmitting 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 Lw = 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 compensation 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 compensation 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, so as to ensure that the sound can meet the sound pressure requirements of the sound collection element when propagating to the position where the sound collection element is located, and further improve 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 extending 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 extending 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 extending direction of the air duct. Therefore, the size of the entire protection device in the direction perpendicular to the extending 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 wind 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. Description of the Drawings

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

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

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

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

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

[0041] Figure 6 is a three-dimensional structural schematic diagram of the protection device according to the embodiment of the present invention installed in the air duct;

[0042] Figure 7 is Figure 6 a transverse sectional view taken along the front-back direction;

[0043] Figure 8 It is a schematic diagram of the sound propagation process at the first sound inlet of the mounting bracket for sound. Specific embodiments

[0044] The present invention 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 invention, 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 invention. 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 in the present invention can be arranged in different directions, these terms indicating directions should be regarded only as illustrative and not as restrictive. 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 invention 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 segment and a second channel segment connected in sequence. Among them, the sound collection element 11 is located in the first channel segment. The first channel segment has a first sound inlet 211 communicating with the second channel segment. The second channel segment 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 segment and the second channel segment are straight channels. Among them, the extension line of the first channel segment intersects with the extension line of the second channel segment. The extension line of the first channel segment can be understood as the connection line between the position where the sound inlet of this channel segment is located and the position where the sound collection element 11 is located. The extension line of the second channel segment can be understood as the connection line between the position where the sound inlet of this channel segment is located and the position where the sound outlet is located.

[0048] The active noise reduction system is usually installed 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 and other kitchen appliances), and the sound collection device is an important part of the active noise reduction system and is also correspondingly installed 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 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, 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 exactly 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 the 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 that extends respectively to the left and right sides and exposes outside the wind shield 40, and a fourth mounting portion 264 that extends downward at the bottom of the mounting bracket 20 and exposes 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 position of the receiving groove 21 of the mounting bracket 20, there is a connecting column 265 that extends forward, and the wind shield 40 can be connected to the connecting column 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 that is 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 inside the air duct 10 (such as Figure 3 the direction indicated by the hollow arrow in the figure). 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, and 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 inside 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 to arrange components such as the wind-proof sound-permeable member 30 and the oil-proof sound-permeable film 28 at the position inside the wind shield 40 that is opposite to the front part of the receiving groove 21. 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 inside the air duct 10 to a certain extent, such as affecting the air volume flowing inside 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 installing 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 internal flow field of 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 installing 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 inside 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 inside 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, for details see Figure 7。

[0053] In order 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, and 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 pollute 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 arranged, 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 and the mounting frame 20 are matched, 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 direction of the main noise source of the range hood, thus ensuring the accuracy of noise collection.

[0056] In this embodiment, the size of the main body of the windproof sound transmission member 30 in the front-rear direction is smaller than the size of the above-mentioned 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 can meet the sound pressure requirements of the sound collection element 11 when it 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 is provided on the upper edge of the windproof cover 40 extending upward 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 will be 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 receiving groove 21 of the mounting bracket 20 and a windproof cover 40 is provided outside the mounting bracket 20, it is possible to effectively isolate the interference of the airflow in the air duct 10 on the sound collection element 11, prevent the oil stain in the airflow from contaminating the sound collection element 11, and at the same time, a windproof and sound-permeable member 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 member 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 member 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 member 30 is arranged in the extension direction of the air duct 10, and the sound propagation path has a turning design, 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 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 at the same time 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, in this embodiment, a structural design is adopted in which the sound collection channel 200 is located on the front side of the receiving groove 21, that is, the opening orientation B1 of the first sound inlet 211 of the receiving 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 receiving 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 member 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 well 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 bracket 20, specifically, it is installed at the position of the front open edge of the receiving groove 21 of the mounting bracket 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 disposed 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 fourth distance f between the above-mentioned 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 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 vertical 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 and back directions, 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 greater wind noise. After the above parameter design, the windproof effect of the windproof sound-permeable 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-permeable member is avoided. 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 to not 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 replenishment 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 compensatory 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 avoid the windproof and sound-permeable member 30 coming into contact with 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 spacing between the windproof and sound-permeable member 30 and the rear side wall of the air duct 10, and this first spacing 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 and 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 and sound-permeable member 30 can effectively prevent 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 materials that can prevent airflow disturbance and transmit sound) itself will have an adverse effect on weakening the sound, so the dimension (i.e., thickness) of the windproof and 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 and sound-permeable member 30 in the front-rear direction is certain, the dimension d1 of the main body of the windproof and sound-permeable member 30 in the left-right direction also needs to be adapted to it, that is, the ratio e / d1 needs to be reasonably limited. 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 and 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 and 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 and 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 relatively large angular 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 and 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 enough to compensate for the sound pressure loss caused by the setting of the windproof and 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 and sound-permeable member, it also means that the windproof effect of the windproof and 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. For this reason, 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 and 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 setting 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 position where the sound collection element 11 is located, 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 accommodation groove 21 of the mounting frame 20 to be received by the sound collection element 11 and achieve the purpose of accurately collecting the noise signal. Specifically, the principle of sound attenuation and compensation is as follows:

[0065] L w = L1 - ΔL + 10lg S 0

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

[0067] The sound pressure when the sound reaches the top surface of the windproof sound-permeable member 30 is L1;

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

[0069] The cross-sectional area S0 of the cross-section at the second sound inlet 45 of the sound collection channel;

[0070] Therefore, if the thickness of the windproof sound-permeable member 30 or the length dimension in the sound propagation path is too large, resulting in serious sound attenuation, then by increasing S0, the sound power L collected by the sound collection element can be ensured w will not become smaller, thereby ensuring the accuracy of sound collection. Specifically, the cross-sectional area of the windproof sound-permeable member 30 near the second sound inlet 45 in this embodiment is denoted as S1, and the cross-sectional area of the sound supplement channel 450 near the second sound inlet 45 is denoted as S2. Then the total cross-sectional area of the cross-section at the second sound inlet 45 of the sound collection channel is (S1 + S2). For example, Figure 3 the cross-section cut along the S3 - S3 direction is the cross-section of the main body of the windproof sound-permeable member 30 near the second sound inlet 45 and the cross-section of the sound supplement channel 450 near the second sound inlet 45. The area of the first sound inlet 211 of the accommodation groove 21 of the mounting frame 20 is denoted as S. The ratio value of the total cross-sectional area (S1 + S2) of the cross-section at the second sound inlet 45 of the sound collection channel to the opening area S at the first sound inlet 211 at the front of the accommodation groove 21 needs to be reasonably limited: (S1 + S2) / S ≥ 0.18. Thus, it can be ensured that sufficient noise can pass through the sound collection channel of the protection device to 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 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 passes 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. For example, 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 it is required that At the same time, in order 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 range of the above parameters satisfies the following conditions:

[0073] After installing the sound collection element 11 in the accommodation groove 21 of the mounting bracket 20 in this embodiment, an oil-proof sound transmission membrane 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 connected to 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 as to minimize the influence of the sound propagation obstruction and further improve the accuracy of noise collection. 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 law of air flow, 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 bracket 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. 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: Further included is a housing (2), on which a sound propagation channel is defined. The sound propagation channel includes a first channel segment and a second channel segment that are connected in sequence and arranged at an angle. The sound collection element (11) is located in the first channel segment. The second channel segment has a second sound inlet (45) for external sound to enter therein. A windproof and sound-permeable member (30) is also provided in the second channel segment. A gap channel extending along the second channel segment is formed between the windproof and sound-permeable member (30) and the inner wall of the second channel segment as a sound supplement channel (450).

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 oil fume extraction device. The second channel segment is arranged along the extension direction of the air duct (10), and the second sound inlet (45) is formed at the windward 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, characterized in that: The first channel segment has a first sound inlet (211) communicating with the second channel segment. The extension line of the opening direction of the first sound inlet (211) is perpendicular to the extension direction of the second channel segment.

4. The sound collection device according to claim 2 or 3, characterized in that: The housing (2) includes a mounting bracket (20) and a windproof cover (40). A receiving groove (21) is formed on the front side wall of the mounting bracket (20). The sound collection element (11) is placed in the receiving groove (21). The receiving groove (21) constitutes the first channel segment. The windproof cover (40) is sleeved outside the mounting bracket (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 bracket (20). The sound collection channel (200) constitutes the second channel segment. The second sound inlet (45) is defined between the windproof cover (40) and the mounting bracket (20) at the windward end. The sound supplement 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 collection device according to claim 4, wherein: 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. Among them, the value range of c / e is: 0.1 ≤ c / e ≤ 0.

45.

7. The sound collection device according to claim 6, characterized in that: 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, wherein: The area of the cross-section of the windproof sound transmission member (30) adjacent to the second sound inlet (45) is denoted as S1, the area of the cross-section of the sound replenishment channel (450) adjacent to the second sound inlet (45) is denoted as S2, and the area of the first sound inlet (211) of the accommodation 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 supplement 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 up-down 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 transmission member (30) includes an extension section (301) extending upward from the top edge of the first sound inlet (211) of the accommodation groove (21), and the length of the extension section (301) of the windproof sound transmission 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 transmission member (30) and the windproof sound transmission 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 an air duct (10) for flue gas to pass through and a sound collection device arranged in the air 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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