Sound acquisition device and range hood

Abstract

The sound collection device 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 connected in sequence and arranged at an included angle, a sound collection element is located in the first channel section, and a sound collection element is located in the second channel section. The first channel section is provided with a first sound inlet communicated with the second channel section, the second channel section is also internally provided with a windproof sound transmission part, the length size of the main body of the windproof sound transmission part in the extension direction of the sound acquisition channel is recorded as g, and the thickness of the part, corresponding to the front side of the first sound inlet, of the windproof sound transmission part is recorded as e; the sectional area of the portion, close to the second sound inlet, of the body of the windproof sound transmission piece is S1, and the value range of S1 / (g / 2 + e / 2) is 10 < = S1 / (g / 2 + e / 2) < = 15. The oil-proof and wind-proof sound collector has the advantages that the oil-proof and wind-proof purposes can be achieved, noise signals can be fully collected, and then the accuracy of sound collection is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of range hoods, and 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 problem of range hoods has always been one of the main problems that trouble users. Active noise reduction, as a new type of noise reduction technology, has also been considered for application on range hoods for noise reduction. An 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, thereby achieving the noise reduction effect. For example, the Chinese invention patent application with the application number CN202010935185.0 (the application publication number: 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 a reduction in the noise reduction effect of the active noise reduction system over time, and even a 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 prevention 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 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 prevention device is arranged below the noise reduction box, and the oil prevention device is also arranged at the bottom of the volute and covers the noise reduction box. The oil prevention 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 prevention 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 film attached to the surface of the porous sound-permeable shell. It does not take into account the influence of wind noise in the air duct of the range hood, that is, no effective wind noise prevention treatment is carried out. On the other hand, for the above-mentioned porous sound-permeable shell, if the number of openings is large, it will have an adverse effect on oil prevention and wind prevention. If the number of openings is small, more noise will be lost during the propagation process, resulting in a reduction in the accuracy of sound collection. Therefore, how to provide a sound collection device that can effectively prevent oil and achieve the purpose of wind noise 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. Therefore, the existing range hood still needs further improvement. 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 achieve the purposes of oil prevention and wind prevention, and can fully collect noise signals, 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 applying the sound collection device, in view of the current situation of the prior art.

[0007] The technical solution adopted by the present invention to solve the 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 first channel segment has a first sound inlet communicating with the second channel segment. The second channel segment has a second sound inlet for external sound to enter. A windproof sound-permeable member is also provided in the second channel segment. The windproof sound-permeable member blocks the front side of the first sound inlet and extends along the length direction of the second channel segment to the second sound inlet. The length dimension of the main body of the windproof sound-permeable member in the extending direction of the second channel segment is denoted as g. The thickness of the part of the windproof sound-permeable member corresponding to the front side of the first sound inlet is denoted as e. The cross-sectional area of the main body of the windproof sound-permeable member near the second sound inlet is S1. Among them, the value range of S1 / (g / 2 + e / 2) is: 10 ≤ S1 / (g / 2 + e / 2) ≤ 15.

[0008] Since the sound collection element is installed in the first channel section of the housing, it can effectively isolate the interference of the airflow in the air duct on the sound collection element, prevent the oil stain in the airflow from contaminating the sound collection element, and at the same time, a windproof and sound-permeable element is provided in the second channel section of the housing, which can effectively eliminate wind noise. Even if a small amount of airflow enters the second channel section, the pressure pulsation can be weakened in the windproof and sound-permeable element, thereby reducing the impact on the accuracy of the microphone's sound collection. With the increase of the size of the windproof and sound-permeable element in the up-down direction, the windproof effect increases, but it also means an increase in the loss during the propagation of sound in the sound collection device. Therefore, on the basis that the size of the windproof and sound-permeable element in the extending direction of the second channel section meets the windproof condition, the sound-permeable area of the windproof and sound-permeable element should be adapted to the above-mentioned size range of the windproof and sound-permeable element to ensure that enough noise to be collected enters the sound collection channel, thereby further reducing the impact of the windproof and sound-permeable element on the sound propagation loss. The size of the main body of the windproof and sound-permeable element in the extending direction of the second channel section is denoted as g, and g / 2 + e / 2 can roughly represent the sound propagation path length in the windproof and sound-permeable element. When the propagation path is long, the sound loss is more. 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), due to the sound loss causing the reduction of the sound pressure during the sound propagation process, as a compensation, S1 should be increased at this time to ensure that enough sound is collected by the sound collection element. Considering the sound propagation loss and compensation factors comprehensively, the value range of S1 / (g / 2 + e / 2) should be: 10mm ≤ S1 / (g / 2 + e / 2) ≤ 15mm. If S1 / (g / 2 + e / 2) is too small, it means that the inlet area for the sound to effectively pass through from top to bottom at the end position of the windproof and sound-permeable element adjacent to the second sound inlet is small, and the amount of sound entering is not enough to balance the adverse effect of the windproof and sound-permeable element on the sound loss in the sound propagation path, reducing the accuracy of the sound collection by the sound collection element. If S1 / (g / 2 + e / 2) is too large, such as S1 / (g / 2 + e / 2) ≥ 15, it means that the inlet area for the sound to enter the second channel section at the end position of the windproof and sound-permeable element adjacent to the second sound inlet is too large, and the windproof effect is correspondingly reduced. Similarly, the area of the upper part of the windproof and sound-permeable element in contact with the oil stain increases, affecting the service life of the windproof and sound-permeable element.

[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 extending direction of the air duct, and the second sound inlet is formed at the end of the housing facing away from the wind.

[0010] The above-mentioned "end part of the housing facing away from the wind" can be understood as: along the extending direction of the air duct, the end of the housing adjacent to the fan system of the range hood.

[0011] The above-mentioned "the second channel section is arranged along the extending direction of the air duct" can be understood as that the overall extending direction of the second channel section is consistent with or parallel to the extending direction of the air duct, or it can also be understood that the overall extending direction of the second channel section has a certain inclination angle relative to the extending direction of the air duct (such as an inclination angle of 0-30°).

[0012] In order to facilitate the sound in the air duct to enter the sound propagation channel more smoothly, the extension line of the opening direction of the second sound inlet is consistent with the extending direction of the air duct, and the extension line of the opening direction of the first sound inlet is perpendicular to the extending direction of the air duct.

[0013] Generally speaking, in order to minimize the oil pollution of the sound collection element on the mounting rack as much as possible, the orientation of the first sound inlet should be avoided to be consistent with the extending direction of the second channel section, that is, the opening direction of the first sound inlet and the extending direction of the second channel section should preferably be set at an included angle. However, the included angle formed between the orientation of the first sound inlet and the extending direction of the second channel section also needs to be reasonably designed. For example, if the included angle formed between the orientation of the first sound inlet and the extending direction of the second channel section is too small, the oil will still enter the first channel section through the first sound inlet and pollute the sound collection element. If the included angle formed between the orientation of the first sound inlet and the extending direction of the second channel section 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, preferably, the opening direction of the first sound inlet faces forward and is perpendicular to the extending direction of the second channel section.

[0014] The housing can be designed with an integral structure, 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 is preferably designed with a split structure assembled by fasteners. Specifically, the housing includes a mounting rack and a wind shield. 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, and the front opening of the receiving groove is the first sound inlet. The wind shield covers outside the mounting rack and defines a sound collection channel that is connected to the first sound inlet of the receiving groove and is located in front of the receiving groove between the wind shield and the mounting rack. This sound collection channel constitutes the second channel section.

[0015] For better avoiding the contact of the sound collection element with oil pollution and considering the windproof effect, the air duct extends vertically, the second channel section also extends vertically, and the opening of the second sound inlet faces upward. Generally, in the extending direction of the air duct, the fan system is usually located above the sound collection device. In order to be adapted to this, so that the second sound inlet faces the source direction of the target noise, the opening of the second sound inlet faces upward.

[0016] As an improvement, the above-mentioned sound collection device is arranged in the air duct of the range hood, and the leeward end of the wind shield and the mounting bracket define the second sound inlet.

[0017] As an improvement, 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 vertical direction is m. Among them, the value range of h / m is: 0.125 ≤ h / m ≤ 0.6. If the value of h / m is too small (such as less than 0.125), it means that the upward extension length of the windproof sound-permeable member is small and insufficient to offset the influence of the air flow pulsation pressure, and the windproof effect is not good. If the value of h / m is too large (such as greater than 0.6), it means that the upward extension length of the windproof sound-permeable member is large. Although the windproof requirement is met, it will have an adverse effect on sound propagation, that is, a part of the sound pressure will be lost, resulting in not enough noise passing through the sound collection channel of the sound collection device and propagating to the accommodation groove, making it difficult to meet the sound pressure requirement of the sound collection element and affecting the accuracy of noise collection.

[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 air flow, eliminate the air flow 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 not only prevent the air flow from impacting the oil-proof sound-permeable membrane 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 function of filtering the noise signal.

[0019] In order to make the size of the sound collection device in the direction perpendicular to the extension direction of the air duct as small as possible, avoid affecting the stability of the air flow in the air duct, and reduce the generation of wind noise, the cross-section of the sound collection channel is a square structure with a large left-right dimension and a small front-back dimension.

[0020] The technical solution adopted by the present invention to solve the second technical problem is: a range hood, including an air duct for flue gas to pass through and an active noise reduction system arranged in the air duct. The active noise reduction system includes a sound collection element for collecting sound signals, and also includes the above-mentioned sound collection device, and the sound collection element is arranged in the sound collection device.

[0021] As an improvement, the sound collection element is a microphone.

[0022] Compared with the prior art, the advantages of the present invention are:

[0023] First, since the sound collection element is installed in the first channel section of the housing and a windproof sound-permeable member is provided in the second channel section, wind noise can be effectively eliminated. Even if a small amount of air flow enters the sound collection channel, the pressure pulsation can be weakened in the windproof sound-permeable member, thereby reducing the impact on the accuracy of microphone sound collection.

[0024] Secondly, as the size of the windproof sound-permeable member in the extending direction of the second channel section increases, the windproof effect increases, but it also means an increase in the loss during the propagation of sound in the sound collection device. Therefore, on the basis that the size of the windproof sound-permeable member in the extending direction of the second channel section meets the windproof condition, the sound-permeable area of the windproof sound-permeable member should be adapted to the above-mentioned size range of the windproof sound-permeable member to ensure that enough noise to be collected enters the sound collection channel, thereby further reducing the impact of the windproof sound-permeable member on sound propagation loss. The size of the main body of the windproof sound-permeable member in the extending direction of the second channel section is denoted as g, and g / 2 + e / 2 can roughly represent the sound propagation path length in the windproof sound-permeable member. When the propagation path is long, more sound is 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), due to the sound loss causing a decrease in the sound pressure during the sound propagation process. As a compensation, S1 should be increased at this time to ensure that enough sound is collected by the sound collection element. Considering the factors of sound propagation loss and compensation comprehensively, the value range of S1 / (g / 2 + e / 2) should be: 10mm ≤ S1 / (g / 2 + e / 2) ≤ 15mm. If S1 / (g / 2 + e / 2) is too small, it means that the inlet area for the sound to be effectively transmitted from top to bottom at the end position of the windproof sound-permeable member adjacent to the second sound inlet is small, and the amount of sound entering is not enough to balance the adverse effects of the windproof sound-permeable member on sound loss in the up-down direction and the front-back direction, reducing the accuracy of the sound collection element. If S1 / (g / 2 + e / 2) is too large, such as S1 / (g / 2 + e / 2) ≥ 15, it means that the inlet area for the sound to be effectively transmitted from top to bottom at the end position of the windproof sound-permeable member adjacent to the second sound inlet is too large, and the windproof effect is correspondingly reduced. Similarly, the area of the upper part of the windproof sound-permeable member in contact with oil stain increases, affecting the service life of the windproof sound-permeable member. Description of the Drawings

[0025] Figure 1 is a three-dimensional structural schematic diagram of the sound collection device according to an embodiment of the present invention;

[0026] Figure 2 is an exploded view of the sound collection device according to an embodiment of the present invention;

[0027] Figure 3 is a vertical sectional view of the sound collection device according to an embodiment of the present invention;

[0028] Figure 4 is Figure 3 a schematic structural diagram after removing the windproof sound transmission component in

[0029] Figure 5 is Figure 3 a cross-sectional view taken along the A-A direction in

[0030] Figure 6 a three-dimensional structural diagram of the sound collection device according to an embodiment of the present invention installed in the air duct;

[0031] Figure 7 is Figure 6 a transverse cross-sectional view taken along the front-rear direction;

[0032] Figure 8 is a schematic diagram of the sound propagation process at the first sound inlet of the mounting bracket. Detailed implementation manners

[0033] The present invention will be further described in detail below in conjunction with the embodiments with reference to the drawings.

[0034] 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 convenience of description and are determined based on the exemplary orientations shown in the drawings. Since the embodiments disclosed by the present invention can be arranged in different directions, these terms indicating directions should be regarded as illustrative rather than restrictive. For example, "upper" and "lower" are not necessarily limited to the directions opposite to or consistent with the direction of gravity.

[0035] Figures 1-7 A preferred embodiment of the sound collection device and the range hood of the present invention is shown.

[0036] 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. 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 linear 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.

[0037] 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., which are 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 casing of the range hood, or can refer to a box structure with a "channel" for 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. The collected noise sound waves are 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 sound waves matching the noise sound waves to neutralize the noise sound waves, so as to achieve the effect of noise reduction. 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.

[0038] 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 frame 20 and a wind-proof cover 40.

[0039] In this embodiment, taking the box body 1 with a "channel" for the separate passage of oil fume as an example, the specific structure of the sound collection device will be described. The channel inside the box body 1 serves as the air duct 10. The mounting bracket 20 can be mounted on the rear side wall of the air duct 10. A receiving groove 21 for placing the sound collection element 11 is formed on the front side wall of the mounting bracket 20, 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 serving 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 for the sound from the outside (the sound collection channel in this embodiment) to enter the receiving groove 21 and be effectively collected by the sound collection element. For example, Figure 8 the openings defined by boundary points such as A1 and A2 of the receiving groove 21 in the circumferential direction are not necessarily the largest open openings in the front part of the receiving groove 21. In the state where the mounting bracket 20 is mounted 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 rear side wall of the air duct 10.

[0040] The mounting bracket 20 also has a third mounting portion 263 extending respectively to the left and right sides and exposed outside the wind shield 40, and a fourth mounting portion 264 extending downward at the bottom of the mounting bracket 20 and exposed 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 by screws. A connecting column 265 extending forward is provided in the lower region of the receiving groove 21 of the mounting bracket 20, and the wind shield 40 can be connected to the connecting column 265 of the mounting bracket 20 by screws 50.

[0041] The wind shield 40 includes a first side wall 411 and a second side wall 412 that are opposite and spaced apart from each other on the left and right, 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. The third side wall 413 of the wind shield 40 has a direction along the airflow in the air duct 10 (such as Figure 3The deflector surface 4130 gradually inclines towards the inside of the air duct 10 (in the direction indicated by the hollow arrow in the middle). Specifically, the deflector 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 arranged to extend vertically 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 deflector 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 deflector surface 4130 of the wind shield 40 at a lower position also enables sufficient space to arrange components such as the windproof and sound-permeable member 30 and the oil-proof and sound-permeable film 28 at a position opposite to the front part of the receiving groove 21 inside the wind shield 40. In addition, considering that if the inclination angle of the deflector 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 deflector surface 4130 of the wind shield 40 needs to be reasonably designed. The included angle formed between the deflector 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°. To reduce the influence of the installation of the sound collection 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 turbulent flow problem of the air flow at the position of the sound collection 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, see Figure 7 。

[0042] To improve the anti-oil and anti-fouling effect, the wind shield 40 in this embodiment can be made of a plastic part or a metal part.

[0043] In this embodiment, a clearance channel extending vertically in the front-rear direction is formed between the wind shield 40 and the front side surface of the mounting frame 20. The upper end of the clearance channel (i.e., the end close to the noise sound source) is open, and the lower end (i.e., the end far from the noise sound source) is closed, which is the sound collection channel 200. The 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 windward end of the wind shield 40 (i.e., the end along the extension direction of the air duct, close to the fan system of the range hood) and the front side wall of the mounting frame 20. The lower part of the sound collection channel 200 is opposite to the first sound inlet 211 at the front part of the receiving groove 21 of the mounting frame 20 in the front-rear direction. The air duct 10 and the sound collection channels in 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 angle M. The value range of the first angle M can be: 5° ≤ M ≤ 180°. Considering that if the 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 receiving groove 21 through the first sound inlet 211 to contaminate the sound collection element 11. If the 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 impact 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 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 angle M is 90°, that is, the opening direction of the first sound inlet 211 is perpendicular to the extension direction of the sound collection channel 200. In addition, the opening direction B4 of the second sound inlet 45 in 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.

[0044] The wind-proof sound-permeable member 30 is disposed in the sound collection channel 200, covers the first sound inlet 211 of the accommodation groove, and the wind-proof sound-permeable member 30 extends to the position where the second sound inlet 45 is located. After the wind-proof cover 40 is installed, it can effectively prevent the high-speed oil fume airflow from directly impacting the wind-proof sound-permeable member 30, greatly reducing the pollution of the oil fume to the wind-proof sound-permeable member 30. At the same time, after the wind-proof cover 40 is combined with the mounting bracket 20, only the upper second sound inlet 45 is retained, directly isolating the lower airflow noise and the noise interference of the secondary turbulent flow, so that the noise entering the wind-proof sound-permeable 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. In a preferred embodiment, in order to improve the protection effect of the wind-proof cover 40 on the wind-proof sound-permeable member 30 and minimize the contact between the wind-proof sound-permeable member 30 and the flue gas in the air duct, an extension wall 46 is provided on the upper edge of the wind-proof cover 40 extending upward relative to the top surface of the wind-proof sound-permeable member 30, that is, the top edge of the extension wall 46 is higher than the top surface of the wind-proof sound-permeable member 30. Affected by the airflow in the air duct 10, an airflow vortex will be formed at the leeward end of the wind-proof cover 40 (that is, at the second sound inlet 45), which will generate obvious wind noise. The setting of the extension wall 46 of the wind-proof 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.

[0045] Since the sound collection element 11 is installed in the receiving groove 21 of the mounting bracket 20 and a wind shield 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 wind-proof 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 wind-proof and sound-permeable member 30, thereby reducing the impact on the accuracy of the microphone sound collection. 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 wind-proof 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 the sound collection, in this embodiment, the sound collection channel 200 for placing the wind-proof 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 sound collection 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 where the sound collection device is located 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 air duct environment of the range hood 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, 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 wind-proof 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 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 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 in the sound collection 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 curved 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.

[0046] The cross-section of the sound collection channel 200 is a square structure with larger left and right dimensions and smaller front and rear dimensions. Correspondingly, the windproof and sound-permeable member 30 is a laminate structure with a uniform thickness. The oil-proof and sound-permeable membrane 28 covers the first sound inlet 211 of the receiving groove 21 of the mounting frame 20, specifically, it is installed at the position of the edge of the front opening of the receiving groove 21 of the mounting frame 20. More specifically, in order to facilitate the installation of the oil-proof and sound-permeable membrane 28 and ensure its sealing performance after installation, 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 and sound-permeable membrane 28 is disposed on the annular step portion 210. In order to ensure the oil-proof performance of the oil-proof and sound-permeable membrane 28 and enable it to effectively transmit sound waves, the oil-proof and sound-permeable membrane 28 of this embodiment is preferably a polyethylene film. Among them, as Figure 3 shown, there is a fourth distance between the oil-proof and sound-permeable membrane 28 and the sound collection element 11, and this fourth distance 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 and sound-permeable membrane 28 and the sound collection element 11 should refer to the distance between the oil-proof and sound-permeable membrane 28 and the microphone chip on the sound collection element 28, that is, the oil-proof and sound-permeable membrane 28 and other components (such as solder joints or fixing screws, etc.) on the circuit board where the microphone chip is located can have partial contact. The windproof and sound-permeable member 30 does not directly contact the oil-proof and sound-permeable membrane 28 to ensure the oil-proof effect. Specifically, there is a sixth distance between the oil-proof and sound-permeable membrane 28 and the main body of the windproof and sound-permeable member 30 in the front-rear direction, and this sixth distance is denoted as n. In order to avoid the contact between the oil-proof and sound-permeable membrane 28 and the windproof and sound-permeable member 30 from affecting the sound transmission effect here, the sixth distance n between the oil-proof and sound-permeable membrane 28 and the windproof and sound-permeable member 30 should be greater than 0.1mm, and the preferred range is 0.5mm - 3mm.

[0047] 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 of this embodiment can not only prevent the airflow from impacting the oil-proof sound-permeable film 28 and generating additional noise, but also, due to 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. More specifically, the front side wall of the windproof sound-permeable member 30 is attached to the rear side wall of the third side wall 413 of the windproof cover 40, so that the windproof sound-permeable member 30 is in a compressed state. By compression, the material density can be increased, effectively reducing the possibility of the penetration of the airflow pressure pulsation, thereby further enhancing the windproof effect.

[0048] 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 there is a turning part in the sound propagation path of the sound collection device at the first sound inlet 211 of the accommodation groove 21, if the upward 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, avoiding the influence on the accuracy of sound collection due to the too short upward 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 either. If h / m is greater than 0.6, it will cause the sound not to effectively meet the sound pressure requirement of the sound collection element 11 when propagating to the accommodation groove 21, reducing the accuracy of noise collection.

[0049] To prevent the windproof sound-transmitting 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 spacing between the windproof sound-transmitting member 30 and the rear side wall of the air duct 10, which 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-transmitting 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-transmitting member 30 effectively prevents the airflow in the air duct from directly impacting the sound collection element 11. Of course, considering the adverse effect of the windproof ball 30 (generally made of porous material that can prevent airflow disturbance and transmit sound) on sound attenuation, the dimension (i.e., thickness) of the windproof sound-transmitting 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-transmitting member 30 in the front-rear direction is fixed, the dimension d1 of the main body of the windproof sound-transmitting member 30 in the left-right direction also needs to be adapted to it, that is, it is necessary to reasonably limit e / d1, and the value range is: 0.2≤e / d1≤0.5. 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-transmitting member 30 in the left-right direction is large, and the area of its upper part in contact with oil stains increases, which will directly affect the service life of the windproof sound-transmitting 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-transmitting member 30 in the left-right direction is small, which is not conducive to the sound being transmitted into the sound collection channel 200 from a large angular range in the horizontal direction above, affecting the accuracy of sound collection.

[0050] Due to the setting of the windproof sound-transmitting member 30 in the sound collection channel 200, 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 bracket 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:

[0051] L w =L1 - ΔL + 10lgS0

[0052] Among them, the noise energy that the sound collection component can collect per unit time is the sound power L w ;

[0053] The sound pressure when the sound reaches the top surface of the windproof sound-transmitting member 30 is L1;

[0054] Due to the attenuation effect of the windproof sound-transmitting member 30, the lost noise sound pressure is ΔL;

[0055] The area S0 of the cross-section at the second sound inlet 45 of the sound collection channel 200;

[0056] Therefore, if the sound is severely attenuated due to the excessive thickness or the length dimension in the sound propagation path of the windproof sound-permeable member 30, the sound power L collected by the sound collection element can be ensured by increasing S0. w will not become smaller, thereby ensuring the accuracy of sound collection. Specifically, the ratio of the area S0 of the cross-section at the second sound inlet 45 of the sound collection channel 200 in this embodiment to the opening area S at the first sound inlet 211 at the front part of the accommodation groove 210 needs to be reasonably limited. When the second sound inlet 45 is relatively small, such as when S0 / S is less than 0.18, it cannot be well ensured that there is enough noise passing through the sound collection channel of the sound collection device to compensate for the sound pressure loss caused by the setting of the windproof sound-permeable member. In this case, the accuracy of sound collection is lower than 80%. Therefore, the value range of S0 / S is S0 / S≥0.18. Thus, it can be ensured that there is enough noise passing through the sound collection channel 200 of the sound collection device to compensate for the sound pressure loss caused by the setting of the windproof sound-permeable member 30 and the turning in the sound propagation path, and then ensure that the sound pressure requirement of the sound collection element 11 can be met when the sound propagates to the accommodation groove 211, further improving the accuracy of noise collection. On the other hand, if the opening area of the second sound inlet 45 is relatively large, such as when S0 / S is greater than 1.5, the accuracy of sound collection basically fluctuates around 98% - 99%. In this case, the improvement of the accuracy of noise collection is small, and the improvement of the active noise reduction effect is weak, but the installation space requirement for the sound collection device is larger. Therefore, the preferred value range of S0 / S is: 0.18≤S0 / S≤1.5. More specifically, when 0.18≤S0 / S<0.3, since the second sound inlet 45 is relatively enlarged, the sound collection channel can be made relatively unobstructed, and the accuracy of sound collection is improved, generally reaching within the range of 80 - 88%. When 0.3≤S0 / S≤1.5, within this range, the accuracy of noise collection is optimal, generally reaching about 91% - 98%. Moreover, the installation space requirement for the sound collection device is also relatively reasonable and will not overly occupy the space in the air duct 10. Therefore, the preferred value range of S0 / S is: 0.3≤S0 / S≤1.5.

[0057] The above-mentioned sound collection accuracy mainly refers to the degree of conformity between the noise collected by the microphone and the original noise. The specific calculation method is as follows: The collection accuracy S is the average value of the accuracy S at different one-third octave center frequency bands within the selected noise frequency range. i of the average value.

[0058]

[0059] Where: n is the number of center octaves in the frequency range of interest:

[0060] Accuracy S in a certain center frequency band i Calculation method:

[0061]

[0062] Where: The sound pressure value L of the collected noise at this center frequency ic ;

[0063] The sound pressure value L of the original noise at this center frequency iy ;

[0064] The dimension of the main body of the windproof sound-permeable member 30 in the present embodiment in the up-down direction 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 and ensure the windproof effect, 100 mm ≥ g ≥ 10 mm. The cross-sectional area of the main body of the windproof sound-permeable member 30 near the second sound inlet 45 is S1. As shown in Figure 3 The cross-section cut along the S1-S1 direction in is the cross-sectional area of the main body of the windproof sound-permeable member 30 near the second sound inlet 45. Among them, g / 2 + e / 2 represents the sound propagation path length in the windproof sound-permeable member. When the propagation path is long, the sound loss is more. 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 known that due to the sound loss, the sound pressure decreases during the sound propagation process. As a compensation, S1 should be increased at this time to ensure that enough sound is collected by the sound collection element. Therefore, considering the sound propagation loss and compensation, the value of S1 / (g / 2 + e / 2) should be greater than 8 mm, and the preferred value range is: 10 mm ≤ S1 / (g / 2 + e / 2) ≤ 15 mm. If S1 / (g / 2 + e / 2) is too small, such as S1 / (g / 2 + e / 2) ≤ 8, it means that the inlet area for the sound to effectively transmit from top to bottom at the end position of the windproof sound-permeable member near the second sound inlet is small, and the amount of sound entering is not enough to balance the adverse effects of the windproof sound-permeable member 30 on the sound loss in the up-down direction and the front-back direction, reducing the accuracy of the sound collected by the sound collection element 11. If S1 / (g / 2 + e / 2) is too large, such as S1 / (g / 2 + e / 2) ≥ 15, it means that the inlet area for the sound to effectively transmit from top to bottom at the end position of the windproof sound-permeable member 30 near the second sound inlet 45 is large. Similarly, the area of the upper part of the windproof sound-permeable member 30 in contact with the oil stain increases, affecting the service life of the windproof sound-permeable member 30.

[0065] In this embodiment, since the windproof sound transmission member 30 is filled in the sound collection channel 200, that is, there is no gap between the front side of the windproof sound transmission member 30 and the windproof cover 40, therefore, the cross-sectional area S1 of the main body of the windproof sound transmission member 30 near the second sound inlet 45 is substantially the same as the area S0 of the cross-section of the second sound inlet 45 of the sound collection channel 200.

[0066] While the protection structure of this embodiment realizes the suppression of wind noise by the sound collection element, it also needs to ensure the passage of noise signals. According to the sound propagation theory, the protection structure consists of acoustic mass M a and acoustic capacitance C a to form a low-pass filter. Therefore, it is necessary to make the cut-off frequency f c of the structure itself greater than the upper frequency limit f a concerned by active noise reduction, so as to accurately collect all the original noise frequencies concerned by active noise reduction.

[0067] Where:

[0068]

[0069] V is the volume of the cavity in the protection structure, specifically the volume of the inner cavity formed by the oil-proof sound transmission membrane and the inner wall of the receiving groove of the mounting frame; ρ0 is the air density; c0 is the speed of sound in air, 343 m / s; L is the path length of sound propagation;

[0070] S0 is the effective area of sound propagation in the pipeline, and can be simplified as the minimum cross-sectional area of the pipeline during sound propagation. In this embodiment, S0 is the area of the cross-section of the second sound inlet 45 of the sound collection channel 200;

[0071]

[0072] The applicant's research found that due to the structural limitations of the range hood and the noise source and its propagation characteristics, for the upper frequency limit f a concerned by the active noise reduction of the range hood, it should be 1200 - 2000 Hz. Therefore, it can be obtained that:

[0073]

[0074] After simplification, it is:

[0075]

[0076] The protection structure of this embodiment must meet the requirements of the above formula.

[0077] More specifically, in this embodiment, S0 is the area of the cross-section of the second sound inlet 45 of the sound collection channel 200, where the second sound inlet 45 is a strip-shaped opening. Thus:

[0078] S0 = ed;

[0079] L is the path length of sound propagation. Since the sound collection channel 200 in this embodiment is not a regular pipeline, it can be simplified as:

[0080]

[0081] Among them, the dimension of the windproof sound-permeable member 30 in the up-down direction is denoted as g, and the dimension (i.e., thickness) of the main body of the windproof sound-permeable member 30 in the front-back direction is denoted as e.

[0082] The above-mentioned

[0083] Further simplified to get:

[0084]

[0085] After installing the sound collection element 11 in the accommodation groove 21 of the mounting rack 20 in this embodiment, an oil-proof sound-permeable membrane 28 is provided at its first sound inlet 211, a windproof sound-permeable member 30 is provided outside it, and a windproof cover 40 is provided outside the windproof sound-permeable member 30. This kind of sound collection device adopts the above three-layer protection to effectively eliminate wind noise and achieve the purpose of preventing oil pollution. After the windproof cover 40 covers the windproof sound-permeable 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-permeable 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-permeable member 30. On the other hand, it also enables the noise to be effectively transmitted to the accommodation groove 21 of the mounting rack 20 through the second sound inlet 45, ensuring the accuracy of noise data collection. On the other hand, considering the influence of the windproof sound-permeable member 30 and the windproof cover 40 on the sound propagation obstruction and loss, the ratio of the opening area S at the first sound inlet of the accommodation groove 21 to the opening area S0 at the second sound inlet 45 of the sound collection channel 200 is limited within a reasonable value range, which can ensure that enough noise passes through this sound collection device and is received by the sound collection element, further improving the accuracy of noise collection.

[0086] This embodiment also relates to a range hood, which includes a flue 10 for the flue gas to pass through and an active noise reduction system provided in the flue 10. The active noise reduction system includes a sound collection device, and the sound collection device is installed on the side wall of the flue 10.

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 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 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. A windproof sound-permeable member (30) is further provided in the second channel segment. The windproof sound-permeable member (30) shields the front side of the first sound inlet (211) and extends along the length direction of the second channel segment to the second sound inlet (45). The length dimension of the main body of the windproof sound-permeable member (30) in the extension direction of the second channel segment is denoted as g. The thickness of the part of the windproof sound-permeable member (30) corresponding to the front side of the first sound inlet (211) is denoted as e. The cross-sectional area of the main body of the windproof sound-permeable member (30) near the second sound inlet (45) is S1. Wherein, the value range of S1 / (g / 2 + e / 2) is: 10 ≤ S1 / (g / 2 + e / 2) ≤ 15.

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).

3. The sound collection device according to claim 2, characterized in that: The extension line of the opening direction of the second sound inlet (45) is consistent with the extension direction of the air duct (10), and the extension line of the opening direction of the first sound inlet (211) is perpendicular to the extension direction of the air duct (10).

4. The sound collection device according to claim 3, wherein: The air duct (10) extends vertically, the second channel segment also extends vertically, and the opening of the second sound inlet (45) faces upward.

5. The sound collection device according to any one of claims 1 to 4, 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 segment. The front opening of the receiving groove (21) is the first sound inlet (211). The windproof cover (40) covers outside the mounting frame (20), and a sound collection channel (200) communicating with the first sound inlet (211) of the receiving groove (21) and located on the front side 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 segment.

6. The sound collection device according to claim 5, wherein: The sound collection device is arranged in the air duct (10) of the oil fume extraction device. The windward end of the windproof cover (40) and the mounting frame (20) define the second sound inlet (45).

7. The sound collection device according to claim 5, wherein: The windproof sound transmission member (30) further includes an extension section extending upward from the top edge of the first sound inlet (211) of the accommodation groove (21), and the length of the extension section of the windproof sound transmission 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. Wherein, the value range of h / m is: 0.125 ≤ h / m ≤ 0.

6.

8. The sound collection device according to claim 5, wherein: The cross-section of the sound collection channel (200) is a square structure with a large left-right dimension and a small front-back dimension.

9. The sound collection device according to any one of claims 1 to 4, characterized in that: The windproof sound transmission member (30) is a sound transmission member made of a porous sound-absorbing material.

10. A range hood, 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 9.

11. The range hood according to claim 10, wherein: The described sound collection element (11) is a microphone.

Images