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 provided with an accommodating groove; the wind shield covers the mounting rack, and a sound acquisition channel of which the main body is arranged along the extension direction of the air duct is defined between the wind shield and the mounting rack; 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 vertical section and an inclined section which are sequentially arranged from top to bottom, the inclined section inclines from the bottom of the vertical section to the side where the accommodating groove is located and is communicated with the accommodating groove, and the first wall surface corresponds to the vertical section; the second wall face corresponds to the inclined section and inclines backwards from top to bottom, the included angle formed by the second wall face and the vertical plane is recorded as N, N is larger than or equal to 5 degrees and smaller than 30 degrees, and the bottom of the first wall face is further provided with a suspended blocking edge. 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 malfunction. For this reason, the Chinese utility model patent application with the application number CN201820250745.7 discloses an active noise reduction device for a range hood with an oil-proof device, which includes an input device, a central data processor, and a noise reduction unit. The input device includes a microphone that is arbitrarily installed at a location on the range hood. The noise reduction unit includes at least two noise reduction boxes that are provided at the bottom of the range hood volute and face the air inlet. An oil-proof device is provided below the noise reduction box, and the oil-proof device is also provided 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 contamination detection module for the noise reduction device. The oil contamination detection module detects the oil contamination of the oil-proof device, and the self-check module receives and processes the self-system signals reported by the device to determine whether there is an increase in the microphone and the noise reduction speaker. At the same time, a timing detection module is provided inside 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 wind noise in the air duct of the range hood, that is, without effective wind noise reduction treatment. 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.

[0004] For another example, the Chinese utility model 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 a 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, and the shell includes:

[0009] A mounting frame is arranged in the air duct, and the sound collecting element is arranged on the mounting frame;

[0010] The wind shield is arranged outside the mounting frame and defines a sound collection channel between the wind shield and the mounting frame 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 leeward end of the wind shield and the mounting frame.

[0011] The mounting frame has a first wall surface and a second wall surface that are connected in sequence vertically and arranged at an angle. The sound collection channel includes a vertical section arranged successively from top to bottom and an inclined section that inclines from the bottom of the vertical section towards the side where the sound collection element is located. The first wall surface corresponds to the vertical section, and the second wall surface corresponds to the inclined section. The second wall surface inclines from top to bottom towards the side where the sound collection element is located, and the angle formed with the vertical plane is denoted as N, and the value range of N is: 5° ≤ N < 30°. A hanging edge that extends downward is further provided at the bottom of the first wall surface.

[0012] The above-mentioned "leeward 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 "connected in sequence vertically" in the above-mentioned "the mounting frame has a first wall surface and a second wall surface that are connected in sequence 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 connected in sequence along the extension direction of the sound collection channel.

[0014] Generally, the sound collection element can be directly installed on the wall surface of the mounting bracket. However, to avoid oil contamination of the sound collection element, a receiving groove is provided on the mounting bracket, and the sound collection element is placed in the receiving groove. The installation of the wind shield of the sound collection device can effectively isolate the interference of the air flow in the air duct to the sound collection element and prevent the oil contamination in the air flow 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 air flow in the air duct and also reduces 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 too much oil from directly passing through the sound collection channel and contacting the sound collection element, but make most of the oil adhere to the side wall of the sound collection channel or the wind-proof sound-transmitting member, so that the sound collection element can be as far away from the oil as possible and the service life of the sound collection element can be extended. Considering that if the turning angle of the sound propagation path is too large, it is not conducive to sound transmission, so the turning angle should be reduced as much as possible. Therefore, the angle N formed by the second wall surface and the vertical plane is designed as: 5° < N ≤ 30°. However, considering that under this angle design, the oil 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. Therefore, a hanging edge extending downward is also provided at the bottom of the first wall surface, so that the oil droplets will gradually accumulate along the hanging edge and drip vertically and will not fall on the sound collection element.

[0015] In order to enable the sound entering the inclined section of the sound collection channel to smoothly enter the receiving groove, the receiving groove has a first sound inlet, and the opening direction of the first sound inlet is parallel to the extension direction of the inclined section of the sound collection channel.

[0016] Considering that the extension direction of the air duct is mostly vertical and the air flow direction in the air duct is from bottom to top, in order to adapt to this, the opening direction of the second sound inlet faces upward.

[0017] To further improve the wind-proof effect, a wind-proof sound-transmitting member is also provided in the sound collection channel. After the wind-proof sound-transmitting member is provided in the sound collection channel, it can prevent the oil contamination in the air flow from contaminating the sound collection element, especially effectively isolate the wind noise. Even if a small amount of air flow enters the sound collection channel, the pressure pulsation can be weakened in the wind-proof sound-transmitting member, thereby reducing the impact on the sound collection accuracy of the microphone.

[0018] In order to reduce or avoid the influence of the installation of the wind shield 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 wind shield has a guiding surface that gradually inclines towards the inside of the air duct along the direction of the air flow in the air duct.

[0019] In order to make the structure of the wind shield correspond and match with that of the mounting bracket, so as to ensure that the whole sound collection device is more compact and small, the guiding surface of the wind shield is opposite to the second wall surface of the mounting bracket front and back, and an inclined section of the sound collection channel is defined between the two.

[0020] The technical solution adopted by the present invention to solve the second technical problem is: an oil fume extractor, which includes an air duct for flue gas to pass through and a sound collection device arranged in the air duct, and the sound collection device adopts the above-mentioned 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 utility model are as follows:

[0023] First of all, the setting of the wind shield 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.

[0024] Secondly, the main body of the sound collection channel is arranged along the extension direction of the air duct, which can make the size of the whole 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 oil fume extractor, and further makes the air resistance at the position where the sound collection device is located in the air duct smaller, so that it will not affect the stability of the air flow in the air duct, and at the same time, it also reduces the generation of wind noise to a certain extent.

[0025] 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 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 accommodation 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. Instead, 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, extending the service life of the sound collection element. Considering that if the turning angle of the sound propagation path is too large, it is not conducive to the transmission of sound. Therefore, the turning angle should be minimized as much as possible. Thus, the angle N formed by the second wall surface and the vertical plane is designed to be: 5° < N ≤ 30°. However, considering that with this angle design, 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. Therefore, a hanging edge extending downward is provided at the bottom of the first wall surface, so that the oil droplets will gradually accumulate along the hanging edge and drip vertically, and will not fall on the sound collection element. On the other hand, the structural design of the turning path for the sound propagation path in the sound collection device has a weakening effect on high-frequency sounds (such as the high-frequency part of the wind noise and the high-frequency sound components generated by the fan system and other non-target noises), and has less impact on low-frequency sounds. Therefore, it can be better applied to the propagation of low-frequency noises in the sound collection device, facilitating the accurate collection of the low-frequency noises by the sound collection element. Description of the Drawings

[0026] Figure 1 Schematic perspective view of the sound collection device according to an embodiment of the present invention;

[0027] Figure 2 Vertical sectional view taken along the front-rear direction of the sound collection device according to an embodiment of the present invention;

[0028] Figure 3 is Figure 2 Vertical sectional view with the windproof sound-transmitting member omitted in;

[0029] Figure 4 Schematic perspective view of the sound collection device according to an embodiment of the present invention installed in the air duct;

[0030] Figure 5 Schematic diagram of the sound propagation process at the first sound inlet of the mounting bracket. Detailed Description of the Embodiment

[0031] The present invention will be further described in detail below with reference to the embodiments of the drawings.

[0032] In the description and claims of the present invention, terms indicating directions, such as "front", "rear", "upper", "lower", "left", "right", "side", "top", "bottom", etc., are used to describe various exemplary structural parts and elements of the present invention. However, these terms are used here only for the purpose of convenience of description and are determined based on the exemplary orientations shown in the drawings. Since the embodiments disclosed in the present invention can be arranged in different directions, these terms indicating directions are only for illustration and should not be regarded as limitations. For example, "upper" and "lower" are not necessarily limited to the directions opposite to or consistent with the direction of gravity.

[0033] Figures 1 - 5 A preferred embodiment of the sound collection device and the range hood of the present invention 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 casing of the range hood or a box structure with a "channel" for the oil fume to pass through alone, such as the channel between the fan system and the smoke collecting hood of the ceiling-mounted range hood. The active noise reduction system generally includes a sound collection element 11 (microphone) and a loudspeaker. That is, the noise generated during the operation of the range hood is collected by the microphone, and the collected noise sound wave is transmitted to the controller in the form of an electrical signal. After being analyzed and processed by the controller, an instruction is sent to the loudspeaker to control the loudspeaker to emit a sound wave matching the noise sound wave to neutralize the noise sound wave, thereby achieving 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.

[0034] 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.

[0035] Taking the box 1 with a "channel" for the oil fume to pass through alone as an example in this embodiment, the specific 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 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 external sound (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 5 the opening defined by boundary points such as A1 and A2 of the receiving groove 21 in the circumferential direction, and does not necessarily refer to the largest open mouth at the front part of the receiving groove 21. In the state where the mounting bracket 20 is installed in place on the rear side wall of the air duct 10, the rear wall of the part of the mounting bracket 20 where the receiving groove 21 is located is in contact with the rear side wall of the air duct 10.

[0036] The mounting bracket 20 further has a third mounting portion 263 extending respectively to the left and right sides and exposing outside the wind shield 40, and a fourth mounting portion 264 extending downward at the bottom of the mounting bracket 20 and exposing outside the wind shield 40. Both the third mounting portion 263 and the fourth mounting portion 264 are connected to the side wall of the air duct 10 by screws.

[0037] 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 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 guiding surface 4130 that gradually inclines toward the inside of the air duct 10 along the air flow direction in the air duct 10 (such as Figure 2 the direction indicated by the hollow arrow in the figure). Specifically, the guiding surface 4130 is located at the lower part of the third side wall 413, that is, at one end of the third side wall 413 facing the wind, and it inclines forward from bottom to top, while the upper part of the third side wall 413 is basically vertically extended and is opposite to the part where the receiving groove 21 of the mounting bracket 20 is located in the front-rear direction. Along the air flow direction in the air duct 10, the position where the guiding surface 4130 of the wind shield 40 is located is upstream of the position where the receiving groove 21 of the mounting bracket 20 is located. Considering that if the inclination angle of the guiding surface 4130 toward the inside of the air duct 10 is too large, it will also affect the air flow condition in the air duct 10 to a certain extent, such as affecting the air volume flowing in the air duct 10 or generating additional noise problems. Therefore, the inclination angle of the guiding surface 4130 of the wind shield 40 needs to be reasonably designed. The included angle formed between the guiding surface 4130 of the wind shield 40 and the side wall of the air duct 10 for mounting the wind shield 40 is denoted as A, and the value range of A is: A ≤ 60°. To improve the anti-oil pollution effect, the wind shield 40 in this embodiment can be made of plastic parts or metal parts.

[0038] In this embodiment, a gap channel extending vertically in the front-rear direction is formed between the wind shield 40 and the front side of the mounting bracket 20. 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 end of the wind shield 40 facing away from the wind (i.e., a section along the extension direction of the air duct, close to the fan system of the range hood) and the front side wall of the mounting bracket 20. The air duct 10 in 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 main body 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 main body of the sound collection channel 200 is too small, the oil 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 main body of the sound collection channel 200 is too large, the sound propagation path turns too much, which will have an adverse effect on sound propagation, that is, a part of the sound pressure will be lost, which is not conducive to the accurate collection of noise by the sound collection element. Therefore, the sound collection channel 200 as a whole extends vertically, and it includes two sections arranged in sequence from top to bottom, specifically including an upper section 201 extending vertically (i.e., the vertical section) and a lower section 202 (i.e., the inclined section) inclined downward from top to bottom toward the position of the receiving 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. The opening orientation B1 of the first sound inlet 211 of the receiving 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 orientation 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 can be: 5° ≤ M < 90°. Preferably, the value range of the first included angle M is: 30° ≤ M ≤ 80°. The parts of the front wall surface of the mounting bracket 20 corresponding to the upper section 201 and the lower section 202 of the sound collection channel 200 are a vertical surface 20a and an inclined surface 20b respectively. In addition, through Figure 3 It can be seen that the position of the vertical surface 20a of the mounting bracket 20 is displaced in the up-down direction from the position of the receiving 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 mounting 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 mounting the mounting bracket 20.

[0039] Corresponding to the above first included angle M, such asFigure 3 As shown, the vertical surface 20a and the inclined surface 20b of the mounting frame 20 of this embodiment intersect to form a second angle N. Due to the difference in viscosity, surface tension and roughness of the wall material of the oil droplets themselves, the oil droplets are subjected to gravity, adhesion, surface tension and friction on the inclined surface. When the inclined surface 20b has different inclination angles (i.e., the second angle N), the combined effect of different forces causes the movement of the oil droplets to be different. When the value of the second angle N is 80°≥N≥30°, since the adhesion and friction forces in the vertical direction against gravity are small, the oil stains flow down from the vertical surface 20a and accumulate at the corner to a certain extent, and then fall directly down. Due to the structural misalignment design, the oil droplets will not drip onto the sound collection element 11. When the value of the second angle N is 30°>N≥5°, since the components of the adhesion and friction forces resisting gravity in the vertical direction are relatively large, the oil will flow down from the vertical surface 20a, pass through the corner, and flow down along the inclined surface 20b to reach the sound collecting element 11. Therefore, the lower end of the vertical surface 20a of the mounting frame 20 also has a hanging stopper 20c extending downward at the position where it is connected to the inclined surface 20b. After adding a hanging stopper 20c extending downward at the corner where the vertical surface 20a of the mounting frame 20 and the inclined surface 20b are connected, the oil droplets will gradually accumulate along the hanging stopper 20c and drip vertically, and will not fall on the sound collecting element 11.

[0040] The above structural design makes the propagation path of the sound in the sound collection device of this embodiment a turning path, such as Figure 2 and Figure 3 The path S is shown in FIG. 1 . Since the turning angle of the sound propagation path of the present embodiment is relatively gentle, while achieving the purpose of oil prevention, it can also avoid as much as possible the loss of target noise caused by too large a turning angle, which affects the accuracy of sound collection. In addition, the sound collection channel 200 of the present embodiment can also be as close to the side wall of the air duct 10 as possible, so as to avoid the sound collection device 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.

[0041] The lower part of the sound collection channel 200 is opposite to the first sound inlet 211 at the front of the accommodation groove 21 of the mounting bracket 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 wind-proof sound-transmitting member 30, greatly reducing the pollution of the oil fume to the wind-proof sound-transmitting member 30. At the same time, after the wind shield 40 is combined with the mounting bracket 20, only the second sound inlet 45 at the upper part 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-transmitting member 30 mainly comes from above, that is, the direction of the main noise source of the range hood, thus ensuring the accuracy of noise collection. In a preferred embodiment, in order to improve the protection effect of the wind shield 40 on the wind-proof sound-transmitting member 30 and minimize the contact between the wind-proof sound-transmitting member 30 and the flue gas in the air duct, an extension wall 46 extends upward from the upper edge of the wind shield 40 relative to the top surface of the wind-proof sound-transmitting member 30, that is, the top edge of the extension wall 46 is higher than the top surface of the wind-proof sound-transmitting 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 (that is, 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.

[0042] Since the sound collection element 11 is installed in the accommodation groove 21 of the mounting bracket 20 and a windproof cover 40 is provided outside the mounting bracket 20, it is possible to effectively isolate the interference of the airflow in the air duct 10 on the sound collection element 11 and prevent the oil stain in the airflow from contaminating the sound collection element 11. At the same time, a windproof and sound-permeable member 30 is provided in the sound collection channel formed between the mounting bracket 20 and the windproof cover 40, which can effectively reduce the influence of wind noise. Even if a small amount of airflow enters the sound collection channel 200, the pressure pulsation can be weakened in the windproof and sound-permeable member 30, thereby reducing the 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 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. And considering that it is necessary to set a windproof and sound-permeable member 30 with a sufficient length on the sound propagation path to prevent wind noise, thereby reducing the influence of the airflow in the air duct 10 on sound collection. In this embodiment, the sound collection channel 200 for placing the windproof and sound-permeable member 30 is arranged in the extension direction of the air duct 10, 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 of the sound collection device in the air duct 10 smaller. Therefore, it will not affect the stability of the airflow 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 the same as the extension direction B3 of the sound collection channel 200, then the sound collection element 11 is easily contaminated by the oil stains 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 stains adhere to the side wall of the sound collection channel 200 or the windproof and sound-permeable member 30, thereby enabling the sound collection element 11 to be as far away from the oil stain as possible and extending the service life of the sound collection element 11.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 well 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.

[0043] The oil-proof sound-permeable membrane 28 covers the first sound inlet 211 of the receiving groove 21 of the mounting frame 20 and covers the outside of the sound collection element 11. The wind-proof sound-permeable member 30 is a laminated structure with uniform thickness, and it is arranged in the sound collection channel 200. In order to effectively slow down the airflow and eliminate the airflow impact, the wind-proof sound-permeable member 30 is a sleeve member made of porous sound-absorbing material. For example, the wind-proof sound-permeable member 30 can be made of polyurethane foam, melamine foam sponge, etc. Among them, the porosity of the wind-proof sound-permeable member 30 is greater than 70%. The wind-proof sound-permeable member 30 of this embodiment can not only prevent the airflow from impacting the oil-proof sound-permeable membrane 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. Specifically, the front side wall of the wind-proof sound-permeable member 30 is attached to the rear side wall of the third side wall 413 of the wind-proof cover 40, so that the wind-proof 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 wind-proof effect. In order to prevent the oil-proof sound-permeable membrane 28 from contacting the wind-proof sound-permeable member 30 and affecting the sound transmission effect here, the sixth distance n between the oil-proof sound-permeable membrane 28 and the wind-proof sound-permeable member 30 should be greater than 0.1 mm, and the preferred range is 0.5 mm to 3 mm.

[0044] To ensure the wind-proof effect, the size (i.e., thickness) of the main body of the wind-proof sound-permeable member 30 in the front-rear direction is denoted as e, where the value range of e is: 40 mm ≥ e ≥ 3 mm. Specifically, when e ≥ 3 mm, it can ensure that the wind-proof sound-permeable 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 wind-proof ball 30 (generally made of porous material that can prevent airflow disturbance and transmit sound) on sound attenuation, the size (i.e., thickness) of the wind-proof sound-permeable member 30 in the front-rear direction cannot be too large, and e ≤ 40 mm is required.

[0045] After installing the sound collection element 11 in the accommodation groove 21 of the mounting bracket 20 in this embodiment, an oil-proof sound transmission membrane 28 is provided at the first sound inlet 211 thereof, a wind-proof sound transmission member 30 is provided outside it, and a wind-proof cover 40 is provided outside the wind-proof sound transmission 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 wind-proof cover 40 covers the wind-proof sound transmission member 30, a second sound inlet 45 communicating with the outside is reserved at the leeward end. According to the law of air flow, the flow in the area of the wind-proof sound transmission 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.

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 within 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 the windscreen 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 extension 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 leeward 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 vertical section (201) arranged from top to bottom in sequence and an inclined section (202) that inclines from the bottom of the vertical section (201) toward the side where the sound collection element (11) is located. The first wall surface (20a) corresponds to the vertical section (201), and the second wall surface (20b) corresponds to the inclined section (202). The second wall surface (20b) inclines downward toward the side where the sound collection element (11) is located from top to bottom, and the angle formed with the vertical plane is denoted as N, and the value range of N is: 5° ≤ N < 30°. A hanging retaining edge (20c) extending downward is further provided at the bottom of the first wall surface (20a).

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), and the opening direction of the first sound inlet (211) is parallel to the extension direction of the inclined section (202) of the sound collection channel (200).

4. The sound collection device according to claim 1, wherein: The opening direction 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: It further includes a windproof and sound-permeable member (30) provided in the sound collection channel (200).

6. The sound collection device according to any one of claims 1 to 4, characterized in that: The windward end of the windscreen (40) has a guiding surface (4130) that gradually inclines toward the inside of the air duct (10) along the air flow direction in the air duct (10).

7. The sound collection device according to claim 6, wherein: The guiding surface (4130) of the windscreen (40) is front and back opposite to the second wall surface (20b) of the mounting bracket (20), and the inclined section (202) of the sound collection channel (200) is defined between the two.

8. 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 sound collection device adopts the sound collection device described in any one of claims 1 to 7.

9. The range hood according to claim 8, characterized in that: The sound collection element (11) is a microphone.

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