Sound acquisition device and range hood

Abstract

The utility model relates to a sound acquisition device and a range hood, the sound acquisition device comprises a housing, the housing comprises a mounting rack arranged in an air duct, and a sound acquisition element arranged on the mounting rack; a sound acquisition channel for transmitting the sound in the air duct to the sound acquisition element is defined between the windproof cover and the mounting frame; the mounting frame is provided with a first wall surface and a second wall surface which are connected up and down and are arranged at an included angle, the sound acquisition channel comprises a first extension section extending in the vertical direction and a second extension section inclining from the bottom of the first extension section to the side where the sound acquisition element is located, and the first wall surface corresponds to the first extension section; the second wall surface corresponds to the second extension section, the included angle formed by the second wall surface and the vertical plane is recorded as N, and the value range of N is that N is more than 30 degrees and less than or equal to 180 degrees. 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 utility model relates to the technical field of range hoods, in particular to a sound collection device and a range hood. Background Art

[0002] A range hood is a kitchen appliance for purifying the kitchen environment. The noise of the range hood has always been one of the main problems troubling users. As a new noise reduction technology, active noise reduction is also considered to be applied to the range hood for noise reduction. The active noise reduction device usually includes a microphone and a speaker, that is, the microphone collects the noise generated when the range hood is working, and the collected noise sound wave is transmitted to the controller in the form of an electrical signal. After being analyzed and processed by the controller, an instruction is sent to the speaker to control the speaker to emit a sound wave matching the noise sound wave to neutralize the noise sound wave, so as to achieve the noise reduction effect. For example, the Chinese invention patent application with the application number CN202010935185.0 (the application publication number is: CN111928310A) discloses such a range hood with an active noise reduction function. The microphone of this range hood is arranged in 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] 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 oily environment of the range hood, the microphones and speakers are often contaminated, resulting in a reduction in the noise reduction effect of the active noise reduction system over time and even failures. For this reason, the Chinese utility model patent application with the application number CN201820250745.7 discloses an active noise reduction device for a range hood with an oil-proof device, which includes 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-proof device is provided 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 provided 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 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 provided in the self-check module. However, the oil-proof device of the active noise reduction device in this patent application still has certain deficiencies. The oil-proof device realizes sound transmission and oil prevention through the porous sound-permeable shell and the oil-proof film attached to the surface of the porous sound-permeable shell, without considering the influence of the wind noise in the air duct of the range hood, that is, no effective wind noise reduction 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 being affected.

[0004] For another example, the Chinese invention patent application with application number CN202111048335.7 (application publication number CN113739232A) discloses a protective device, a range hood and a control method for the range hood, wherein the protective device comprises: a connecting pipe, suitable for installation in the housing of the range hood, the connecting pipe having a first end and a second end; a first protective member, arranged at the second end, the first protective member being suitable for sound to pass through but not suitable for oil to pass through; a second protective member, arranged at the first end, the second protective member being suitable for installing an active noise reduction device, and the second protective member being connected to the inside of the connecting pipe. The sound generated during the operation of the range hood will pass through the first protective member into the connecting pipe and into the active noise reduction device. The active noise reduction device reduces noise during operation, and the oil generated during the operation of the range hood cannot pass through the first protective member and cannot pollute the active noise reduction device. However, this patent application also only performs anti-oil pollution treatment, and 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 performed. In particular, the arrangement of the above-mentioned connecting pipe will occupy a large space in the air duct, and the airflow in the air duct will generate a large wind noise when passing through the connecting pipe. The wind noise will pass through the connecting pipe and enter the position of the microphone, causing a large impact on the accuracy of the microphone in collecting the target noise.

[0005] In summary, how to provide a sound collection device that can effectively prevent oil and achieve the purpose of wind protection, thereby ensuring the accuracy of sound collection has become a technical problem that needs to be urgently solved by technical personnel in this field. Utility Model Content

[0006] The first technical problem to be solved by the utility model is to provide a sound collection device which can achieve the purpose of oil and wind protection and can fully collect noise signals, thereby ensuring the accuracy of sound collection, in view of the current status of the existing technology.

[0007] The second technical problem to be solved by the utility model is to provide a range hood using the above-mentioned sound collection device in view of the current status of the prior art.

[0008] The technical solution adopted by the utility model to solve the first technical problem is: a sound collection device is arranged in the air duct of the range fumes suction device, which includes a shell and a sound collection element arranged in the shell for collecting sound signals, including:

[0009] A mounting frame, on which the sound collecting element is arranged;

[0010] The wind shield is arranged outside the mounting bracket, and a sound collection channel is defined between the wind shield and the mounting bracket for the sound in the air duct to be transmitted to the position where the sound collection element is located. The main body of the sound collection channel is arranged along the extension direction of the air duct. A second sound inlet that is connected to the sound collection channel and allows sound to enter the sound collection channel is defined between the windward end of the wind shield and the mounting bracket.

[0011] The mounting bracket has a first wall surface and a second wall surface that are connected vertically and arranged at an angle. The sound collection channel includes a first extension section extending vertically and a second extension section that slopes from the bottom of the first extension section towards the side where the sound collection element is located. The first wall surface corresponds to the first extension section, and the second wall surface corresponds to the second extension section. The angle formed by the second wall surface and the vertical plane is denoted as N, and the value range of N is: 30° < N ≤ 180°.

[0012] The above-mentioned "windward end of the wind shield" can be understood as: along the extension direction of the air duct, the end of the wind shield adjacent to the fan system of the range hood.

[0013] The above-mentioned "the first wall surface corresponds to the first extension section, and the second wall surface corresponds to the second extension section" can be understood as that the first wall surface of the mounting bracket and the corresponding part of the wind shield define the first extension section of the sound collection channel, and the second wall surface of the mounting bracket and the corresponding part of the wind shield define the second extension section of the sound collection channel.

[0014] The "vertically connected" in the above-mentioned "the mounting bracket has a first wall surface and a second wall surface that are connected vertically and arranged at an angle" is not limited to the vertical direction in the actual installation environment of the range hood or the sound collection device, and should be understood as: the first wall surface and the second wall surface are sequentially connected along the extension direction of the sound collection channel.

[0015] Generally, the sound collection element can be directly mounted on the wall surface of the mounting bracket. However, to prevent the sound collection element from being contaminated by oil stains, a receiving groove is provided on the mounting bracket, and the sound collection element is placed in the receiving groove. The setting of the windproof cover of the sound collection device can effectively isolate the interference of the airflow in the air duct on the sound collection element and prevent the oil stains in the airflow from contaminating the sound collection element. The sound collection channel is arranged along the extension direction of the air duct, which can make the size of the entire sound collection device in the direction perpendicular to the extension direction of the air duct smaller, that is, it occupies less space in the air duct of the range hood, and thus the wind resistance at the position of the sound 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 reduce the generation of wind noise to a certain extent. The first wall surface and the second wall surface on the mounting bracket are arranged at an angle, and the sound collection channel is correspondingly divided into a vertical section and an inclined section. Thus, the entire path of the noise in the air duct entering the sound collection channel from the second sound inlet and then propagating to the position of the sound collection element in the receiving groove is a turning path. This turning path can prevent excessive oil stains from directly passing through the sound collection channel and contacting the sound collection element, but make most of the oil stains adhere to the side wall of the sound collection channel or the windproof sound-transmitting member, so that the sound collection element can be as far away from the oil stains as possible and the service life of the sound collection element can be extended. However, considering that if the angle between the second wall surface and the vertical plane is too small, the oil stains may flow down from the first wall surface of the mounting bracket through the corner and along the second wall surface to reach the sound collection element 11, affecting the accuracy of noise collection and the service life of the sound collection element 11. Therefore, the angle N formed by the second wall surface and the vertical plane is designed to be: 30° < N ≤ 180°.

[0016] Considering that too many turning paths in the sound collection device will also have an adverse impact on sound propagation, in order to make the sound entering the inclined section of the sound collection channel enter the receiving groove more smoothly, the receiving groove has a first sound inlet for the sound in the sound collection channel to enter the receiving groove, and the orientation of the first sound inlet is parallel to the extension direction of the second extension section of the sound collection channel.

[0017] 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 sound collection device and to consider the convenience of installing components such as the windproof and sound-permeable parts within the sound collection channel, the extension direction of the main body of the sound collection channel is consistent with the extension direction of the air duct. Generally speaking, to minimize the contamination of the sound collection elements on the mounting bracket by oil stains, the first wall surface on the mounting bracket should be set at an angle to the second wall surface. In particular, the angle formed between the second wall surface and the vertical plane also needs to be reasonably designed. If the angle formed between the second wall surface and the vertical plane is too small, the oil liquid will flow from the first wall surface through the corner to the second wall surface and then enter the accommodation groove through the first sound inlet to contaminate the sound collection elements. Therefore, the first wall surface of the mounting bracket extends vertically, the second wall surface slopes backward from top to bottom, and the value range of the angle N formed with the vertical plane is: 30° < N < 90°; or

[0018] the first wall surface of the mounting bracket extends vertically, the second wall surface extends horizontally backward from the bottom of the first wall surface, and the value range of the angle N formed with the vertical plane is: N = 90°; or

[0019] the first wall surface of the mounting bracket extends vertically, the second wall surface slopes backward from bottom to top, and the value range of the angle N formed with the vertical plane is: 90° < N < 180°; or

[0020] the first wall surface and the second wall surface of the mounting bracket are arranged in sequence in the front-rear direction and both extend vertically. The bottom of the first wall surface is connected to the bottom of the second wall surface, and the value range of the angle N formed between the second wall surface and the vertical plane is: N = 180°.

[0021] Considering that when the second angle N is 90° or close to 90°, it is sufficient to achieve a good anti-oil effect, that is, the oil liquid dripping from the first wall surface basically will not flow to the position where the sound collection elements are located. However, if the second angle continues to increase, the turning angle of sound propagation will correspondingly increase, and the target noise loss will increase. That is, when the target noise reaches the position where the sound collection elements are located, the sound pressure cannot meet the sound collection requirements, affecting the accuracy of sound collection. Therefore, the value of the second angle N of the present utility model is preferably: N = 90°.

[0022] The "vertical extension" in the present utility model, such as the "vertical extension" in the above-mentioned "the first wall surface of the mounting bracket extends vertically", is not limited to the vertical direction and can also be inclined at a certain angle (such as 0° - 30°) relative to the "vertical direction".

[0023] In the present utility model, the front-back direction, such as the front-back direction in the above-mentioned "the second wall surface inclines backward from top to bottom", is not limited to the front-back direction in the actual installation environment of the range hood or the air duct, but should be understood as: the side close to the sound collection element is the back, and the side far from the sound collection element is the front. For example, when the sound collection device in the present utility model is installed on the left side wall of the air duct, the above-mentioned "the second wall surface inclines backward from top to bottom" should be understood as: the second wall surface inclines leftward from top to bottom, that is, it inclines toward the side where the sound collection element is located.

[0024] Considering that the air duct of the range hood mostly extends vertically, in order to be adapted thereto, the sound collection channel extends vertically, and the opening direction of the second sound inlet faces upward.

[0025] To improve the windproof effect, it further includes a windproof and sound-permeable member provided in the sound collection channel. After the windproof and sound-permeable member is provided in the sound collection channel, wind noise is effectively eliminated. Even if a small amount of air flow enters the sound collection channel, the pressure pulsation can be weakened in the windproof and sound-permeable member, thereby reducing the influence on the sound collection accuracy of the microphone.

[0026] To reduce or avoid the influence of the setting of the windproof cover on the air flow in the air duct, such as affecting the air volume flowing in the air duct or generating additional noise problems, the windward end of the windproof cover has a guiding surface that gradually inclines toward the inside of the air duct along the air flow direction in the air duct.

[0027] To make the windproof cover and the mounting bracket structurally correspond and fit, so as to ensure that the overall sound collection device is more compact and small, the guiding surface of the windproof cover and the second wall surface of the mounting bracket face each other front and back, and the inclined section of the sound collection channel is defined between the two.

[0028] 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 a sound collection device provided in the air duct, and the sound collection device adopts the above-mentioned sound collection device.

[0029] As an improvement, the sound collection element is a microphone.

[0030] Compared with the prior art, the advantages of the present utility model are:

[0031] First of all, the setting of the windproof cover of the sound collection device can effectively isolate the interference of the air flow in the air duct on the sound collection element, and play a role in preventing the oil stain in the air flow from polluting the sound collection element.

[0032] Secondly, the main body of the sound collection channel is arranged along the extending direction of the air duct, which can make the size of the entire sound collection device in the direction perpendicular to the extending direction of the air duct smaller, that is, it occupies less space in the air duct of the range hood, and further makes the air resistance at the position where the sound collection device is located in the air duct smaller. Therefore, 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.

[0033] Furthermore, the first wall surface and the second wall surface on the mounting bracket are arranged at an angle, and the sound collection channel is correspondingly divided into a first extension section and a second extension section. Thus, the entire path of the noise in the air duct entering the sound collection channel from the second sound inlet and then propagating to the position where the sound collection element is located is a turning path. This turning path can prevent too much oil stain from directly passing through the sound collection channel and contacting the sound collection element, but make most of the oil stain adhere to the side wall of the sound collection channel or the windproof sound-transmitting member. Thus, the sound collection element can be as far away from the oil stain as possible, extending the service life of the sound collection element. However, considering that if the angle between the second wall surface and the vertical plane is too small, the oil stain may flow down from the first wall surface of the mounting bracket, pass through the corner, and flow down along the second wall surface to reach the sound collection element 11, affecting the accuracy of noise collection and the service life of the sound collection element 11. Therefore, the angle N formed by the second wall surface and the vertical plane is designed as: 30° < N ≤ 180°. The above angle design also creates a relatively large turning corner in the sound propagation path. In this way, the loss of the pressure pulsation caused by the sudden change of the air flow at the leeward end of the windproof cover transmitted to the sound collection element is greater, and the wind noise prevention effect is better. Thus, the required path (the length of the windproof sound-transmitting member) in the extending direction of the first extension section of the sound collection channel can also be correspondingly reduced, so that the overall size of the sound collection device in the extending direction of the air duct can also be made smaller. 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 high-frequency sounds in wind noise and 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 noises in the sound collection device, facilitating the accurate collection of the sound collection element. Description of the Drawings

[0034] Figure 1 Schematic three-dimensional structure diagram of the sound collection device according to Embodiment 1 of the present utility model;

[0035] Figure 2 Exploded view of the sound collection device according to Embodiment 1 of the present utility model;

[0036] Figure 3 Vertical sectional view of the sound collection device according to Embodiment 1 of the present utility model;

[0037] Figure 4 is a sectional view taken along the A-A direction in Figure 3 ;

[0038] Figure 5 is a three-dimensional structural schematic diagram of the sound collection device according to Embodiment 1 of the present utility model installed in the air duct;

[0039] Figure 6 is Figure 5 a transverse sectional view taken along the front-rear direction;

[0040] Figure 7 is Figure 3 a structural schematic diagram with the windproof sound-permeable member omitted in

[0041] Figure 8 is a schematic diagram of the sound propagation process at the first sound inlet of the mounting bracket;

[0042] Figure 9 is a vertical sectional view of the sound collection device according to Embodiment 2 of the present utility model;

[0043] Figure 10 is Figure 9 a structural schematic diagram with the windproof sound-permeable member omitted in

[0044] Figure 11 is a vertical sectional view of the sound collection device according to Embodiment 3 of the present utility model;

[0045] Figure 12 is Figure 11 a structural schematic diagram with the windproof sound-permeable member omitted in

[0046] Figure 13 is a vertical sectional view of the sound collection device according to Embodiment 4 of the present utility model;

[0047] Figure 14 is Figure 13 a structural schematic diagram with the windproof sound-permeable member omitted in

[0048] Figure 15 is a vertical sectional view of the sound collection device according to Embodiment 5 of the present utility model;

[0049] Figure 16 is Figure 15 a structural schematic diagram with the windproof sound-permeable member omitted in. Detailed implementation manners

[0050] The present utility model will be further described in detail below with reference to the embodiments in the accompanying drawings.

[0051] In the description and claims of the present utility model, terms indicating directions are used, such as "front", "rear", "upper", "lower", "left", "right", "side", "top", "bottom", etc., to describe various example structural parts and elements of the present utility model. However, the use of these terms here is only for the purpose of convenient description and is determined based on the example orientations shown in the drawings. Since the embodiments disclosed by the present utility model 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.

[0052] Embodiment 1

[0053] Figures 1 - 7 A preferred embodiment of the sound collection device and the range hood of the present utility model is shown. The active noise reduction system of the range hood is usually arranged in the air duct of the range hood. The above-mentioned "air duct" can refer to the housing of the range hood or a box structure with a "channel" for the separate passage of oil fumes, such as the channel between the fan system and the smoke collecting hood of the ceiling-mounted range hood. The active noise reduction system generally includes a sound collection element 11 (microphone) and a loudspeaker, that is, the microphone collects the noise generated when the range hood works, 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 loudspeaker to control the loudspeaker 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.

[0054] The sound collection device includes a housing 2, an oil-proof sound-transmitting membrane 28, and a wind-proof sound-transmitting member 30. The housing 2 includes a mounting bracket 20 and a wind-proof cover 40.

[0055] In this embodiment, taking the box 1 with a "channel" for the separate passage of oil fumes 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 for placing the sound collection element 11 is provided on its front side wall. The front part of the receiving groove 21 has an opening as a 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 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, such as Figure 8The openings defined by boundary points such as A1 and A2 of the accommodation groove 21 in the circumferential direction do not necessarily refer to the largest opening at the front of the accommodation groove 21. In the state where the mounting frame 20 is mounted in place on the rear side wall of the air duct 10, the rear wall of the portion of the mounting frame 20 where the accommodation groove 21 is located is in contact with the rear side wall of the air duct 10. In order to improve the accuracy of sound collection of the active noise reduction system, generally two or more sound collection elements 11 are arranged. Therefore, components such as the mounting frame 20, the windproof sound-permeable member 30, and the windproof cover 40 are also correspondingly provided with two or more.

[0056] The mounting frame 20 also has a third mounting portion 263 extending respectively to the left and right sides and exposed outside the windproof cover 40, and a fourth mounting portion 264 extending downward at the bottom of the mounting frame 20 and exposed outside the windproof cover 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 at the lower region of the accommodation groove 21 of the mounting frame 20, and the windproof cover 40 can be connected to the connecting column 265 of the mounting frame 20 by screws 50.

[0057] The windproof cover 40 includes a first side wall 411 and a second side wall 412 that are opposite and spaced apart from each other 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 windproof cover 40 is located on the front side of the accommodation groove 21 of the mounting frame 20. The third side wall 413 of the windproof cover 40 has a structure along the air flow direction 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 frame 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 frame 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°. In order 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 by which 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 by which the wind shield 40 protrudes forward is too large, such as b / a > 0.35, on the one hand, it will affect the air volume flowing in the air duct 10, and on the other hand, it will also cause a turbulence problem for the air flow at the position of the 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 6 .

[0058] In order 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.

[0059] In this embodiment, a vertically extending gap channel is formed between the front side of the wind shield 40 and the mounting bracket 20 in the front-rear direction. The upper end of the 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. 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., a section 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 bracket 20. The air duct 10 of this embodiment also extends 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 B3 of the sound collection channel 200 to form a first included angle. Considering that if the included angle formed between the orientation B1 of the first sound inlet 211 and the extension direction B3 of the sound collection channel 200 is too small, 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 included angle formed between the orientation B1 of the first sound inlet 211 and the extension direction B3 of the sound collection channel 200 is too large, the sound propagation path turns too much, which will have an adverse effect on sound propagation, that is, a part of the sound pressure will be lost, and it is not conducive to the accurate collection of noise by the sound collection element. Therefore, the included angle formed between the orientation of the first sound inlet 211 and the extension direction B3 of the sound collection channel 200 also needs to be reasonably designed. The value range of this first included angle is: 30° < M ≤ 180°. More preferably, the value of the first included angle in this embodiment is 90°, that is, the opening direction B1 of the first sound inlet 211 is perpendicular to the extension direction B3 of the sound collection channel 200.

[0060] The sound collection channel 200 includes a first extension section 201 extending vertically and a second extension section 202 inclined from the bottom of the first extension section 201 toward the side where the receiving groove 21 is located. The extension direction of the second extension section 202 is the same as the opening orientation of the first sound inlet 211 of the receiving groove 21, that is, both are horizontally extended. The first wall surface 20a of the mounting bracket 20 corresponds to the first extension section 201 and also extends vertically, while the second wall surface 20b corresponds to the second extension section 202 and is horizontally extended. The first wall surface 20a and the second wall surface 20b of the mounting bracket 20 are substantially perpendicular. As Figure 7As shown, the included angle N formed by the second wall surface 20b and the vertical plane is 90°. The lower part of the sound collection channel 200 (i.e., the second extension section 202) is opposite to the first sound inlet 211 at the front of the accommodation groove 21 of the mounting frame 20 in the front-rear direction. After the wind shield 40 is installed, it can effectively prevent the high-speed oil fume airflow from directly impacting the windproof sound-permeable member 30, greatly reducing the pollution of the oil fume to the windproof sound-permeable member 30. At the same time, after the wind shield 40 is combined with the mounting frame 20, only the upper second sound inlet 45 is retained, directly isolating the lower airflow noise and the noise interference of the secondary turbulent flow, so that the noise entering the windproof 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 shield 40 on the windproof sound-permeable member 30 and minimize the contact between the windproof sound-permeable member 30 and the flue gas in the air duct, the upper edge of the wind shield 40 extends upward relative to the top surface of the windproof sound-permeable member 30 with an extension wall 46, that is, the top edge of the extension wall 46 is higher than the top surface of the windproof 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 shield 40 (i.e., at the second sound inlet 45), which will generate obvious wind noise. The setting of the extension wall 46 of the wind shield 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 target noise to be collected entering from the second sound inlet 45.

[0061] Since the sound collection element 11 is installed in the accommodation groove 21 of the mounting bracket 20 and a wind shield 40 is provided outside the mounting bracket 20, the interference of the air flow 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 air flow. At the same time, a wind-proof and sound-permeable member 30 is provided in the sound collection channel formed between the mounting bracket 20 and the wind shield 40, which can effectively reduce the influence of wind noise. Even if a small amount of air flow enters the sound collection channel 200, the pressure pulsation can be weakened in the wind-proof and sound-permeable member 30, thereby reducing the influence 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 air flow 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. And 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 air flow in the air duct 10 on 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, 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 air flow in the air duct 10 and at the same time reduce 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 opening direction B1 of the first sound inlet 211 is consistent with the extension direction B3 of the sound collection channel 200, then the sound collection element 11 is easily contaminated by the oil stain flowing down along the air duct 10. Therefore, in this embodiment, the opening direction B1 of the first sound inlet 211 of the accommodation groove 21 and the extension direction B3 of the sound collection channel 200 are set at a certain angle, which makes the entire sound propagation path from the noise in the air duct 10 entering the sound collection channel 200 through the second sound inlet 45 and then propagating to the position of the sound collection element 11 in the accommodation groove 21 a turning path. This turning path can prevent too much oil stain from directly passing through the sound collection channel 200 and contacting the sound collection element 11, but make most of the oil stain 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.Furthermore, 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.

[0062] The oil-proof sound-transmitting membrane 28 covers the first sound inlet 211 of the receiving groove 21 of the mounting frame 20, specifically 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 sound-transmitting membrane 28 and ensure its sealing performance after installation, an annular step portion 210 is further 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, as Figure 3 shown, 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≥0.1mm, the preferred range is: 0.5 - 3mm, and the more preferred range is: 2 - 3mm. Thus, it is avoided that the film vibrates or undergoes micro-deformation and contacts the sound collection element 11, resulting in sound propagation variation and affecting the accuracy of sound collection. It can be understood that the above-mentioned fourth distance f between the oil-proof sound-transmitting membrane 28 and the sound collection element 11 should refer to the distance between the oil-proof sound-transmitting membrane 28 and the microphone chip on the sound collection element 28, that is, the oil-proof sound-transmitting membrane 28 can have partial contact with other components (such as solder joints or fixing screws, etc.) on the circuit board where the microphone chip is located.

[0063] 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, which can effectively reduce the possibility of the penetration of the airflow pressure pulsation, thereby further improving the windproof effect. In order to prevent the oil-proof sound-permeable film 28 from contacting the windproof sound-permeable member 30 and affecting the sound transmission effect here, the sixth distance n between the oil-proof sound-permeable film 28 and the windproof sound-permeable member 30 should be greater than 0.1 mm, and the preferred range is 0.5 mm to 3 mm.

[0064] The windproof sound-permeable member 30 of this embodiment includes an extension section 301 extending upward from the top edge of the first sound inlet 211 of the accommodation groove 21. The length of the extension section 301 of the windproof sound-permeable member 30 is denoted as h, and the size of the first sound inlet 211 of the accommodation groove 21 in the up-down direction is m. Among them, the value range of h / m is: 0.125 ≤ h / m ≤ 0.6. Since the sound collection channel 200 has a vertical section extending vertically and a horizontal section extending in the front-rear direction, that is, there is a turning part at the first sound inlet 211 of the accommodation groove 21. If the extension length of the outer peripheral edge part of the windproof sound-permeable member 30 relative to the edge of the first sound inlet 211 of the accommodation groove 21 is too short (such as h / m is less than 0.125), it will also be affected by relatively large wind noise. After the above parameter design, the windproof effect of the windproof sound-permeable member is effectively guaranteed, and the accuracy of sound collection is prevented from being affected due to the too short extension length of the outer peripheral edge of the windproof sound-permeable member. Of course, considering the adverse effect of the windproof sound-permeable member 30 on sound attenuation, the length dimension of the extension section 301 of the windproof sound-permeable member 30 should not be too large. If h / m is greater than 0.6, it will cause the sound not to effectively meet the sound pressure requirements of the sound collection element 11 when propagating to the accommodation groove 21, reducing the accuracy of noise collection.

[0065] To avoid the windproof sound-permeable member 30 coming into contact with the oil flowing continuously down 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-permeable 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-permeable member 30 in the front-back direction is denoted as e. Among them, the value range of e is: 40mm≥e≥3mm. Specifically, when e≥3mm, it can ensure that the windproof sound-permeable member 30 can effectively prevent 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 materials that can prevent airflow disturbance and transmit sound) on sound attenuation, therefore, the dimension (i.e., thickness) of the windproof sound-permeable member 30 in the front-back direction cannot be too large, and e≤40mm is required. At the same time, when the dimension (i.e., thickness) of the windproof sound-permeable member 30 in the front-back direction is fixed, the dimension d1 of the main body of the windproof sound-permeable member 30 in the left-right direction also needs to be adapted to it, that is, it is necessary to reasonably limit e / d1. Specifically, if e / d1 is too small (such as e / d1<0.2), it means that the dimension of the main body of the windproof sound-permeable member 30 in the left-right direction is large, and the area of its upper part in contact with the oil stain increases, which will directly affect the service life of the windproof sound-permeable member 30. If e / d1 is too large (such as e / d1>0.5), it means that the dimension of the main body of the windproof sound-permeable member 30 in the left-right direction is 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.

[0066] Due to the setting of the windproof sound-permeable 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 the noise signal. Specifically, the principles of sound attenuation and compensation are as follows:

[0067] L w =L1 - ΔL + 10lgS0

[0068] Among them, the noise energy that the sound collection component can collect per unit time is the sound power L w ;

[0069] The sound pressure when the sound reaches the top surface of the windproof sound-permeable member 30 is L1;

[0070] Due to the attenuation effect of the windproof sound-permeable member 30, the lost noise sound pressure is ΔL;

[0071] The cross-sectional area S0 of the second sound inlet 45 of the sound collection channel 200;

[0072] Therefore, if the thickness of the windproof sound transmission member 30 or the length dimension in the sound propagation path is too large, resulting in severe sound attenuation, then by increasing S0, the sound power L collected by the sound collection element can be ensured w not to decrease, 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 of the first sound inlet 211 at the front part of the accommodation groove 210 needs to be reasonably limited. Among them, S0 / S≥0.18, whereby it can be ensured that sufficient noise can pass through the sound collection channel 200 of the sound collection device, compensating for the sound pressure loss caused by the setting of the windproof sound transmission member 30, and thereby ensuring 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.

[0073] On the other hand, the size 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 size of the first sound inlet 211 at the front part of the accommodation groove and ensure the windproof effect, 100mm≥g≥10mm. The cross-sectional area of the main body of the windproof sound transmission member 30 near the second sound inlet 45 is S1. Among them, g / 2+e / 2 represents the sound propagation path length in the windproof sound transmission 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 seen that the sound pressure decreases during the sound propagation process due to sound loss. 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 8mm, and the preferred value range is: 10mm~15mm. If S1 / (g / 2+e / 2) is too small, such as S1 / (g / 2+e / 2)≤8, it means that the inlet area for the sound to effectively transmit from top to bottom at the end position of the windproof sound transmission 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 transmission member 30 on sound loss in the up-down direction and the front-back direction, reducing the accuracy of 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 transmission member 30 near the second sound inlet 45 is large. Similarly, the area of the upper part of the windproof sound transmission member 30 in contact with the oil stain increases, affecting the service life of the windproof sound transmission member 30.

[0074] In this embodiment, since the windproof sound-permeable member 30 is filled in the sound collection channel 200, that is, there is no gap between the front side surface of the windproof sound-permeable member 30 and the windproof cover 40, therefore, the cross-sectional area S1 of the main body of the windproof sound-permeable 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.

[0075] 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.

[0076] Where:

[0077]

[0078] V is the volume of the cavity in the protection structure, specifically the volume of the inner cavity surrounded by the oil-proof sound-permeable 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;

[0079] S0 is the effective area of sound propagation in the pipeline, and can be simply taken 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;

[0080]

[0081] 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:

[0082]

[0083] After simplification, it is:

[0084]

[0085] The protection structure of this embodiment must meet the requirements of the above formula.

[0086] 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:

[0087] S0 = ed;

[0088] 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:

[0089]

[0090] Wherein, 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.

[0091] The above

[0092] Further simplified to:

[0093]

[0094] After installing the sound collection element 11 in the accommodation groove 21 of the mounting bracket 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 law of air flow, 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. The existence of the low-speed and high-static-pressure area reduces the wind noise here, and further ensures that the target noise to be collected (i.e., the noise of the fan system) can be effectively transmitted to the accommodation groove 21 of the mounting bracket 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.

[0095] This embodiment also relates to a range hood, including a flue 10 for 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 element 11 for collecting sound signals. The sound collection element 11 uses a microphone, and the microphone is arranged in the accommodation groove 21 of the mounting bracket 20 of the above sound collection device, and then is installed on the side wall of the flue 10 through this sound collection device.

[0096] Embodiment 2

[0097] Figure 9 and Figure 10 Another preferred embodiment of the sound collection device and range hood of the utility model is shown. The difference between this embodiment and embodiment 1 is that the whole of the sound collection channel 200 is a linear channel extending vertically, including a first extension section 201 extending vertically and a second extension section 202 inclined from the bottom of the first extension section 201 toward the side where the receiving groove 21 is located. The first extension section 201 of the sound collection channel 200 is the main body, and has a certain inclination angle relative to the vertical direction, specifically, it is inclined backward from top to bottom. The extension direction of the second extension section 202 is consistent with the opening direction of the first sound inlet 211 of the receiving groove 21, that is, both are extended horizontally. The first wall 20a of the mounting frame 20 corresponds to the first extension section 201 and is also extended vertically, while the second wall 20b corresponds to the second extension section 202 and is extended horizontally. The angle between the first wall 20a and the second wall 20b of the mounting frame 20 is an obtuse angle. As shown in FIG. Figure 10 As shown, the angle N formed by the second wall 20b and the vertical plane is 90°. The first angle M formed between the direction of the first sound inlet 211 and the extension direction of the sound collection channel 200 is an acute angle, and the value range is: 5°≤M<90°. Preferably, the value range of the first angle M is: 30°≤M≤80°, wherein the size of the first angle M is consistent with the deflection angle of the path during the sound propagation process. Figure 9 It can be seen that the propagation path of the sound in the sound collection device of this embodiment is a turning path, such as Figure 9 The turning path S is shown in FIG. Since the turning angle of the sound propagation path of this embodiment is relatively gentle compared to that of Embodiment 1, while achieving the purpose of oil prevention, it can also avoid as much as possible the loss of target noise caused by excessive turning angles, which affects the accuracy of sound collection.

[0098] The present embodiment also relates to a range hood, comprising an air duct 10 for smoke to pass through and an active noise reduction system arranged in the air duct 10, the active noise reduction system comprising a sound collecting element 11 for collecting sound signals, the sound collecting element 11 is a microphone, the microphone is arranged in a receiving groove 21 of a mounting frame 20 of the above-mentioned sound collecting device, and then installed on the side wall of the air duct 10 through the sound collecting device.

[0099] Example 3

[0100] Figure 11 and Figure 12Another preferred embodiment of the sound collection device and the range hood of the present utility model is shown. The difference between this embodiment and Embodiment 1 is that: the sound collection channel 200 extends vertically as a whole, and it includes two sections arranged in sequence from top to bottom, specifically including an upper section 201 extending vertically (i.e., the first extension section) and a lower section 202 (i.e., the second extension section) that is inclined downward from top to bottom toward the accommodation groove 21 of the mounting bracket 20. Among them, the upper section 201 of the sound collection channel 200 is the main part of the sound collection channel 200 and it extends vertically. The opening direction B1 of the first sound inlet 211 of the accommodation groove 21 of the mounting bracket 20 is set obliquely upward, and its inclination direction is the same as the inclination direction of the lower section 202 of the sound collection channel 200. More specifically, the first included angle M formed between the opening direction B1 of the first sound inlet 211 and the extension direction of the upper section 201 of the sound collection channel 200 is also an acute angle, and its value range is: 5° ≤ M < 90°. Preferably, the value range of the first included angle M is: 30° ≤ M ≤ 80°. The parts corresponding to the upper section 201 and the lower section 202 of the sound collection channel 200 on the front wall surface of the mounting bracket 20 are a vertical surface 20a (i.e., the first wall surface) and an inclined surface 20b (i.e., the second wall surface) respectively. In addition, through Figure 12 It can be seen that the position of the vertical surface 20a of the mounting bracket 20 is displaced in the vertical direction from the position of the accommodation groove 21 (i.e., the position where the sound collection element 11 is located), that is, the sound collection element 11 is closer to the side wall of the air duct 10 for installing the mounting bracket 20, while the vertical surface 20a of the mounting bracket 20 is relatively far from the side wall of the air duct 10 for installing the mounting bracket 20.

[0101] As Figure 12 shown, in this embodiment, the inclined surface 20b of the mounting bracket 20 intersects with the vertical plane to form a second included angle N. Due to the differences in the viscosity, surface tension, and wall material roughness of the oil droplets themselves, the oil droplets are subject to gravity, adhesion force, surface tension, and frictional force on the inclined surface. When the inclination angle of the inclined surface 20b is different (i.e., the second included angle N), the combined action of different forces causes the movement of the oil droplets to be different. As shown in 12, when the value of the second included angle N is 80° ≥ N ≥ 30°, since the component forces of the adhesion force and the frictional force resisting gravity in the vertical direction are relatively small, the oil stain flows down from the vertical surface 20a and accumulates at the corner. After increasing to a certain extent, it directly drops, and due to the misaligned design in the structure, the oil droplets will not drip onto the sound collection element 11. The propagation path of sound in the sound collection device of this embodiment is a turning path, as Figure 11 and Figure 12The path S is shown in FIG. 1 and FIG. 2 . Since the turning angle of the sound propagation path of this embodiment is relatively gentle compared to that of (Example 1), while achieving the purpose of oil prevention, it can also avoid as much as possible the loss of target noise caused by excessive turning angles, which affects the accuracy of sound collection. Moreover, compared with Example 2, the sound collection channel 200 of this embodiment can also be as close to the side wall of the air duct 10 as possible, avoiding the sound collection device from protruding too much relative to the side wall of the air duct 10 in the air duct 10 and affecting the stability of the air flow in the air duct 10.

[0102] The present embodiment also relates to a range hood, comprising an air duct 10 for smoke to pass through and an active noise reduction system arranged in the air duct 10, the active noise reduction system comprising a sound collecting element 11 for collecting sound signals, the sound collecting element 11 is a microphone, the microphone is arranged in a receiving groove 21 of a mounting frame 20 of the above-mentioned sound collecting device, and then installed on the side wall of the air duct 10 through the sound collecting device.

[0103] Example 4

[0104] Figure 13 and Figure 14 Another preferred embodiment of the sound collection device and the range hood of the utility model is shown. The difference between this embodiment and the first embodiment is that the sound collection channel 200 is a vertically extending straight channel as a whole. The sound collection channel 200 includes a first extension section 201 extending vertically and a second extension section 202 inclined from the bottom of the first extension section 201 toward the side where the receiving groove 21 is located, wherein the first extension section 201 extends vertically and is the main part, and the second extension section extends backward from bottom to top. Correspondingly, the opening direction of the first sound inlet 211 of the receiving groove 21 of the mounting frame 20 is set obliquely downward, that is, the extension direction of the second extension section is consistent with the opening direction of the first sound inlet 211 of the receiving groove 21. The height of the location of the sound collection element 11 in the receiving groove 21 is higher than the height of the opening position of the first sound inlet 211. The first angle M formed between the opening direction B1 of the first sound inlet 211 and the extension direction of the main body of the sound collection channel 200 (i.e., the first extension section 201) is an obtuse angle, and its value range is: 90°<M<180°. Preferably, the value range of the first angle M is: 100°<M<150°. Figure 13 It can be seen from FIG. 1 that the propagation path of the sound in the sound collection device in this embodiment is a turning path of "first propagating downward and then obliquely upward", such as Figure 13The path S shown in [figure]. Since the turning angle of the sound propagation path in this embodiment is relatively large (compared with Embodiment 1), especially, the opening of the first sound inlet 211 is set obliquely downward, so it can achieve a better anti-oil purpose. However, due to the too large turning angle, certain losses of the target noise are caused, which has a certain impact on the accuracy of sound collection.

[0105] See Figure 14 , the mounting bracket 20 has a first wall surface 20a corresponding to the first extension section 201 of the sound collection channel 200 and a second wall surface 20b corresponding to the second extension section 202. The first wall surface extends vertically, while the second wall surface slopes backward from bottom to top. As Figure 13 shown, the second wall surface 20b of the mounting bracket 20 in this embodiment forms a second angle N with the vertical plane, and the value range of the second angle N is 90° < N < 180°. Preferably, the value range of the second angle N is: 100° < N < 150°.

[0106] This embodiment also relates to a range hood, including a flue 10 for 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 element 11 for collecting sound signals. The sound collection element 11 uses a microphone, and the microphone is arranged in the accommodation groove 21 of the mounting bracket 20 of the above-mentioned sound collection device, and then is installed on the side wall of the flue 10 through the sound collection device.

[0107] Embodiment 5

[0108] Figure 15 and Figure 16 shows another preferred embodiment of the sound collection device and the range hood of the present invention. The difference between this embodiment and Embodiment 1 is that: the main body of the sound collection channel 200 includes a first extension section 201 and a second extension section 202 arranged in sequence from front to back. Both the first extension section 201 and the second extension section 202 extend vertically. Among them, a horizontal section 204 extending horizontally is further provided at the lower part of the first extension section 201, and the lower part of the second extension section 202 is connected to one end of the horizontal section 204. The opening direction of the first sound inlet 211 of the accommodation groove 21 of the mounting bracket 20 faces downward and is connected to the upper part of the second extension section. The first angle M formed between the orientation of the first sound inlet 211 and the extension direction of the main body of the sound collection channel 200 is a flat angle, that is, the value range of the first angle M is 180°. Correspondingly, the mounting bracket 20 has a first wall surface 20a and a second wall surface 20b arranged in sequence from front to back. Both the first wall surface 20a and the second wall surface 20b extend vertically. The bottom of the first wall surface 20a is connected to the bottom of the second wall surface 20b, and the value range of the angle N formed by the second wall surface 20b and the vertical plane is: N = 180°. From Figure 15It can be seen that the propagation path of sound in the sound collection device of this embodiment is a turning path of "first propagating downward, then propagating horizontally, and finally propagating upward", as Figure 15 The turning path S is shown in Figure 15 . Since the sound collection channels of this embodiment are divided into multiple segments arranged vertically and horizontally, and the opening direction of the first sound inlet 211 faces downward, the sound propagation path in the sound collection device of this embodiment has undergone two "turns". Therefore, it can also achieve a good anti-oil purpose. However, due to the excessive turning angle and the large number of turns, certain losses are generated in the target noise, which has a certain impact on the accuracy of sound collection.

[0109] This embodiment also relates to an oil fume extractor, which includes a flue 10 for the passage of flue gas and an active noise reduction system arranged in the flue 10. The active noise reduction system includes a sound collection element 11 for collecting sound signals. The sound collection element 11 uses a microphone, and the microphone is arranged in the receiving groove 21 of the mounting bracket 20 of the above-mentioned sound collection device, and then is installed on the side wall of the flue 10 or on the mounting components of the flue 10 such as a cross beam through this sound collection device.

Claims

1. A sound collection device is disposed in the air duct (10) of an oil fume suction device, and it includes a housing (2) and a sound collection element (11) disposed in the housing (2) for collecting sound signals, and is characterized in that: The housing (2) includes: a mounting bracket (20), on which the sound collection element (11) is provided; a windscreen (40), which is arranged outside the mounting bracket (20) and defines a sound collection channel (200) between it and the mounting bracket (20) for the sound in the air duct (10) to be transmitted to the position where the sound collection element (11) is located. The main body of the sound collection channel (200) is arranged along the extending direction of the air duct (10). A second sound inlet (45) that is connected to the sound collection channel (200) and through which sound enters the sound collection channel (200) is defined between the windward end of the windscreen (40) and the mounting bracket (20); The mounting bracket (20) has a first wall surface (20a) and a second wall surface (20b) that are vertically connected and arranged at an angle. The sound collection channel (200) includes a first extension section (201) that extends vertically and a second extension section (202) that slopes from the bottom of the first extension section (201) towards the side where the sound collection element (11) is located. The first wall surface (20a) corresponds to the first extension section (201), and the second wall surface (20b) corresponds to the second extension section (202). The angle formed by the second wall surface (20b) and the vertical plane is denoted as N, and the value range of N is: 30° < N ≤ 180°; 2. The sound collection device according to claim 1, wherein: A receiving groove (21) is provided on the mounting bracket (20), and the sound collection element (11) is placed in the receiving groove (21); 3. The sound collection device according to claim 2, characterized in that: The receiving groove (21) has a first sound inlet (211) through which the sound in the sound collection channel (200) enters the receiving groove (21). The orientation of the first sound inlet (211) is parallel to the extending direction of the second extension section (202) of the sound collection channel (200); 4. The sound collection device according to claim 3, characterized in that: The first wall surface (20a) of the mounting bracket (20) extends vertically, the second wall surface (20b) slopes backward from top to bottom, and the value range of the angle N formed by it and the vertical plane is: 30° < N < 90°; or The first wall surface (20a) of the mounting bracket (20) extends vertically, the second wall surface (20b) extends backward horizontally from the bottom of the first wall surface (20a), and the value range of the angle N formed by it and the vertical plane is: N = 90°; or The first wall surface (20a) of the mounting bracket (20) extends vertically, the second wall surface (20b) slopes backward from bottom to top, and the value range of the angle N formed by it and the vertical plane is: 90° < N < 180°; or The first wall surface (20a) and the second wall surface (20b) of the mounting bracket (20) are arranged in sequence in the front - rear direction and both extend vertically. The bottom of the first wall surface (20a) is connected to the bottom of the second wall surface (20b), and the value range of the angle N formed by the second wall surface (20b) and the vertical plane is: N = 180°; 5. The sound collection device according to claim 1, wherein: The opening direction of the second sound inlet (45) is upward.

6. The sound collection device according to any one of claims 1 to 5, characterized in that: It further includes a windproof sound-permeable member (30) disposed in the sound collection channel (200).

7. The sound collection device according to any one of claims 1 to 5, characterized in that: One end of the windproof cover (40) facing the wind has a guiding surface (4130) that gradually inclines towards the inside of the air duct (10) along the air flow direction in the air duct (10).

8. The sound collection device according to claim 7, characterized in that: The guiding surface (4130) of the windproof cover (40) is opposite to the second wall surface of the mounting bracket (20) front and back, and an inclined section of the sound collection channel (200) is defined therebetween.

9. A range hood, comprising a duct (10) for flue gas to pass through and a sound collection device disposed in the duct (10), characterized in that: The sound collection device adopts the sound collection device described in any one of claims 1 to 8.

10. The range hood according to claim 9, characterized in that: The sound collection element (11) is a microphone.

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