Installation structure of active noise reduction system of oil smoke suction device and range hood

Abstract

The utility model relates to an active noise reduction system installation structure of a lampblack suction device and a range hood, an active noise reduction system comprises a sound collection device, the sound collection device is arranged in an air duct of the lampblack suction device, and the air duct is provided with a first side wall, a second side wall and an airflow inlet, the first direction is perpendicular to the extending direction of the air channel, the airflow inlet is arranged adjacent to the first side wall, at least one sound collecting device is arranged adjacent to the second side wall, the distance between the first side wall and the second side wall of the air channel is a, the distance between the sound collecting device and the second side wall is recorded as L1, and L1 and a meet the relation that L1 / a is larger than 0 and smaller than 0.3. The sound collection device is arranged on the side, away from the airflow inlet, in the air duct, so that the adverse effect of secondary noise (wind noise) generated when the sound collection device is directly impacted by airflow on sound collection can be better reduced, and the sound collection accuracy is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of kitchen appliances, and in particular to an installation structure of an active noise reduction system of a range hood suction device and a range hood. Background Art

[0002] Fume extraction devices, such as range hoods and integrated stoves with fume extraction functions, are kitchen appliances that purify the kitchen environment. The noise generated during operation has long been a major issue for users. Active noise reduction, a new noise reduction technology, is also being considered for use in range hoods. Active noise reduction devices typically include a microphone and a speaker. The microphone collects the noise generated by the range hood during operation and transmits the collected noise waves as electrical signals to a controller. The controller analyzes and processes the noise and issues a command to the speaker, controlling it to emit sound waves that match the noise waves to neutralize them, thereby achieving the desired noise reduction effect. For example, Chinese invention patent application number CN202010935185.0 (publication number CN111928310A) discloses a range hood with active noise reduction. The microphones are located within the housing and arranged in an array around the fan, while the speaker assembly is located below the fan. For example, similar disclosures were made in the “Ranger hood and its active noise reduction device” with application number CN202221822214.3 and the “Low-noise range hood” with application number CN202222650354.3.

[0003] The range hoods in the aforementioned patent applications still have certain deficiencies. First, the microphones are not rationally and specifically arranged within the duct according to the airflow conditions within the duct. Instead, they are simply arranged in an array around the fan or on the sidewalls of the duct. The large number of microphones can cause congestion within the duct and occupy installation space for other components within the duct. Furthermore, because the effects of the airflow conditions within the duct on the microphones' wind noise are not considered, if the microphones are placed in an area with high airflow velocity within the duct, the secondary noise (wind noise) generated by the airflow passing through the microphones will also be greater. Therefore, the large number of microphones can significantly affect the accuracy of the sound collection by the active noise reduction device. In particular, existing microphone devices (sound collection devices) primarily provide only anti-oil treatment without considering the impact of wind noise within the range hood's duct. In other words, they lack effective wind noise protection, which seriously affects the accuracy of sound collection and reduces the effectiveness of the active noise reduction device. Utility Model Content

[0004] The first technical problem to be solved by the present invention is to provide an installation structure of an active noise reduction system of a range hood device, which is capable of reasonably arranging the installation position of a sound collection device according to the airflow state in the air duct and improving the accuracy of sound collection, in response to the current status of the existing technology.

[0005] The second technical problem to be solved by the present invention is to provide a range hood using the above-mentioned active noise reduction system installation structure in response to the current status of the existing technology.

[0006] The technical solution adopted by the present invention to solve the first technical problem is: an installation structure of an active noise reduction system for a range fumes extraction device, the active noise reduction system including a sound collecting device, the sound collecting device being arranged in an air duct of the range fumes extraction device, the air duct having a first side wall and a second side wall opposite to each other in a first direction and an air flow inlet for air flow to enter the air duct, the above-mentioned first direction is perpendicular to the extension direction of the air duct, the air flow inlet is arranged adjacent to the first side wall, at least one sound collecting device is arranged adjacent to the second side wall, the distance between the first side wall and the second side wall of the air duct is a, the spacing between the sound collecting device and the second side wall is recorded as L1, and the relationship between L1 and a satisfies the following: 0<L1 / a<0.3.

[0007] Taking the plane formed by each point in the middle of the air duct in the first direction and along the extension direction of the air duct as the reference plane, the above-mentioned "the air flow inlet is arranged adjacent to the first side wall, and at least one sound collection device is arranged adjacent to the second side wall" can be understood as: the air flow inlet and the at least one sound collection device are respectively located on both sides of the reference plane.

[0008] The above-mentioned "air flow inlet" refers to an opening on the "box" or "a section of air duct" where the sound collection device is located. The opening can be directly connected to the outside, or it can be formed on a box (such as a smoke hood) connected to the above-mentioned "box" or "a section of air duct".

[0009] The above-mentioned “distance between the sound collecting device and the second side wall” should be understood as the distance from the side of the main body of the sound collecting device farthest from the second side wall to the second side wall.

[0010] In the air duct, the airflow velocity on the side adjacent to the airflow inlet in the first direction is greater, while the airflow velocity on the side away from the airflow inlet is less. According to the airflow state in the air duct, the sound collection device is arranged on the side of the air duct away from the airflow inlet. This can better reduce the adverse effects of secondary noise (wind noise) generated by the sound collection device being directly impacted by the airflow on the sound collection, thereby improving the accuracy of sound collection. At the same time, considering that sound propagation in the air duct will be affected by the wall reflection of the air duct side wall, the closer to the air duct side wall, the more sound is reflected by the wall, affecting the signal collection of the sound collection element, resulting in a significant difference between the noise signal detected by the sound collection element and the main wave propagated by the array in the air duct. Therefore, the sound collection device should also be arranged as far as possible in the area of the air duct away from the air duct wall, that is, arranged on the main path of noise propagation in the air duct. Of course, this is also for more accurate and comprehensive noise collection. However, the greater the distance between the sound collection device and the second side wall, the closer the sound collection device is to the second side wall, which means that the sound collection device is located. The closer to the central area of the air duct, the greater the flow rate of the air flow adjacent to the central area of the air duct, and the greater the sound collection device is affected by wind noise. For this reason, the distance between the sound collection device and the second side wall needs to select a suitable value range, specifically using the above-mentioned definition: L1 and a satisfy the relationship: 0<L1 / a<0.3. Within this range, it can not only reduce the influence of the reflection of the air duct wall during the sound collection process, but also avoid as much as possible the influence of wind noise due to excessive proximity to the central area of the air duct (the flow rate of the air flow in this area is also greater), while ensuring the comprehensiveness of sound collection, thereby further improving the accuracy of sound collection.

[0011] Taking into account that the air flow condition on the flow path in the air duct is related to the relative position of the fan and the air inlet in the first direction, and the sound collecting device is arranged adjacent to the second side wall, the distance between the line between the fan and the air inlet and the second side wall needs to be reasonably designed to avoid the sound collecting device being too close to the high flow velocity area in the middle of the air duct and being affected by strong wind noise. Specifically, a fan is further provided in the air duct of the range fumes extraction device or at the port of the air duct, and the fan includes a volute and an impeller arranged in the volute, the axis of the impeller extends vertically, and the air inflow The center position of the port is recorded as point F1, the center position of the bottom port of the impeller passing through the axis of the impeller is recorded as point F2, and the line connecting point F1 and point F2 is recorded as line segment F1F2. The sound collection device is arranged in the area between the line segment F1F2 and the second side wall in the air duct. The shortest distance between the line segment F1F2 and the second side wall in the first direction is recorded as S1. The distance between the first side wall 101 and the second side wall 102 of the air duct 10 is a, where the value range of S1 / a satisfies the following condition: S1 / a ≥ 1 / 10.

[0012] The "center position" of the above-mentioned air flow inlet can be understood as the geometric center of a plane area surrounded by the boundary outline of the air flow inlet. For example, when the air flow inlet is a regular structure such as a circle, an ellipse, or a rectangle, its "center position" is the center point position.

[0013] Taking into account that the air flow condition on the flow path in the air duct is related to the relative position of the fan and the air inlet in the first direction, and the sound collecting device is arranged adjacent to the second side wall, the distance between the line between the fan and the air inlet and the second side wall needs to be reasonably designed to avoid the sound collecting device being too close to the high flow velocity area in the middle of the air duct and being affected by strong wind noise. Specifically, a fan is further provided in the air duct of the range fumes extraction device or at the port of the air duct, the fan includes a volute and an impeller arranged in the volute, the volute includes an annular wall and a cover plate connected to the axial ends of the annular wall, and the impeller The axis extends horizontally, the center position of the air flow inlet is recorded as point F1, the center position of the bottom of the annular wall in its width direction is recorded as point F3, and the line between point F1 and point F3 is recorded as line segment F1F3. The sound collection device is arranged in the area between the line segment F1F2 and the second side wall in the air duct. The shortest distance between the line segment F1F3 and the second side wall in the first direction is recorded as S2. The distance between the first side wall 101 and the second side wall 102 of the air duct 10 is a, where the value range of S2 / a satisfies the following condition: S2 / a ≥ 1 / 10.

[0014] Considering that the airflow velocity in the air duct is related to the position of the airflow inlet and the front-to-back dimension of the airflow inlet, the larger the front-to-back dimension of the airflow inlet, the greater the impact of wind noise on the sound collection device at the same position. Therefore, the sound collection device should be as close to the second side wall as possible, and L1 should be appropriately reduced. Similarly, the greater the distance between the center of the airflow inlet and the first side wall, that is, the closer the airflow inlet is to the central area of the airflow duct, the greater the impact of wind noise on the sound collection device at the same position. L1 should also be appropriately reduced. The distance between the side edge of the airflow inlet adjacent to the first side wall and the first side wall in the first direction is denoted as c, and the value range of c is: 0<c<50mm. The dimension of the airflow inlet in the first direction is denoted as c1, wherein c1, a, and L1 satisfy the following conditions:

[0015] 0.05<L1 / a<0.3, when 1 / 5<c1 / a<1 / 3;

[0016] 0.05<L1 / a<0.25, when 1 / 3≤c1 / a<2 / 3.

[0017] In order to enable the airflow to flow more smoothly along the extension direction of the air duct after entering the air duct through the above-mentioned airflow inlet, and to reduce the impact of airflow disturbance caused by cross-sectional mutation on the accuracy of noise collected by the sound collection device, the direction of the opening of the airflow inlet is consistent with the extension direction of the air duct.

[0018] In order to facilitate the installation of the sound collecting device in the air duct and ensure that the corresponding spacing requirements are met between the sound collecting device and the second side wall of the air duct, a crossbeam is provided in the air duct along a direction parallel to the second side wall, and the sound collecting device is arranged on the crossbeam.

[0019] Only one sound collecting device can be set adjacent to the first side wall, but the influence of reflection from the left and right side walls of the air duct can be avoided. The position of the sound collecting device in the second direction should be reasonably selected. The air duct has a third side wall and a fourth side wall relative to each other in the second direction. The second direction is perpendicular to the first direction and the extension direction of the air duct. The distance between the third side wall and the fourth side wall is recorded as b. There is one sound collecting device set adjacent to the first side wall. The distance between the sound collecting device and the third side wall is recorded as b1, and the distance between the sound collecting device and the fourth side wall is recorded as b2. b1, b3 and b meet the following conditions: 1 / 5≤b1 / b≤1 / 2; 1 / 5≤b2 / b≤1 / 2.

[0020] The above-mentioned "distance between the sound collecting device and the third side wall" should be understood as the distance from the center position of the main body of the sound collecting device (the center position in the second direction) to the third side wall. Similarly, the above-mentioned "distance between the sound collecting device and the fourth side wall" should be understood as the distance from the center position of the main body of the sound collecting device (the center position in the second direction) to the fourth side wall.

[0021] Generally, during single-sided cooking, the air volume on the left and right sides of the range hood is also controlled (e.g., by varying the ventilation area of the oil grilles on the left and right air inlets). Consequently, there is a difference in air volume between the left and right sides of the air duct. To minimize or eliminate the adverse effects of this air volume difference on the accuracy of sound collection, two or more sound collection devices can be positioned adjacent to the first side wall and dispersed as much as possible. Specifically, the air duct has a third side wall and a fourth side wall facing each other in a second direction, the second direction being perpendicular to both the first direction and the extension direction of the air duct. The distance between the third side wall and the fourth side wall is denoted as b. At least two sound collection devices are positioned adjacent to the first side wall, each of which is sequentially spaced apart along the second direction. The distance between the sound collection device adjacent to the third side wall and the third side wall is denoted as b1', and the distance between the sound collection device adjacent to the fourth side wall and the fourth side wall is denoted as b2'. b, b1', and b2' satisfy the following conditions: 1 / 6 ≤ b1' / b ≤ 2 / 5; 1 / 6 ≤ b2' / b ≤ 2 / 5.

[0022] Similarly, the above-mentioned "distance between the sound collecting device and the third side wall" should be understood as the distance from the center position of the main body of the sound collecting device (the center position in the second direction) to the third side wall. Similarly, the above-mentioned "distance between the sound collecting device and the fourth side wall" should be understood as the distance from the center position of the main body of the sound collecting device (the center position in the second direction) to the fourth side wall.

[0023] As an improvement, a sound collection device is also provided within the air duct adjacent to the first sidewall. The sound collection device adjacent to the first sidewall is referred to as a first sound collection device, and the sound collection device adjacent to the second sidewall is referred to as a second sound collection device. The number of first sound collection devices is greater than or equal to the number of second sound collection devices. Considering that the side of the air duct adjacent to the airflow inlet is the primary path for noise propagation and contains the most comprehensive noise signal information, in a preferred embodiment, a larger number of sound collection devices are provided along this path to more comprehensively collect noise information within the air duct.

[0024] In order to effectively reduce the adverse effects of secondary noise (wind noise) generated by the air flow in the air duct passing through the sound collection device on sound collection, the sound collection device can be placed as close to the central area of the air duct as possible to ensure the comprehensiveness of the sound collection signal. The sound collection device includes a shell and a sound collection element. The shell defines a sound propagation channel. The sound collection element is arranged in the sound propagation channel. The shell has a second sound inlet for the sound in the air duct to enter the sound propagation channel. The second sound inlet is located on the leeward side of the shell.

[0025] Placing the sound collecting element inside the shell can better prevent oil pollution and wind noise. In particular, setting the second sound inlet at the leeward end of the shell can facilitate the sound collecting element to directly receive the noise in the air duct and avoid being directly impacted by the airflow in the air duct.

[0026] The technical solution adopted by the present invention to solve the second technical problem is: a range hood, including an air duct and an active noise reduction system, the active noise reduction system including a sound collection device, a speaker and a controller, the controller receives a noise signal from the sound collection device and generates a noise reduction signal, which is then transmitted to the speaker to emit a noise reduction wave, the sound collection device and the speaker are both arranged in the air duct of the range hood, and also includes the above-mentioned range hood device active noise reduction system installation structure.

[0027] Compared with the prior art, the advantages of the present invention are as follows: the airflow velocity in the air duct is higher on the side adjacent to the airflow inlet in the first direction, while the airflow velocity is lower on the side further away from the airflow inlet. Based on the airflow conditions in the air duct, the sound collection device is positioned on the side of the air duct away from the airflow inlet. This can effectively reduce the adverse effects of secondary noise (wind noise) generated by the sound collection device being directly impacted by the airflow on the sound collection device, thereby improving the accuracy of sound collection. Furthermore, considering that sound propagation in the air duct is affected by wall reflections from the side walls of the air duct, the closer to the side walls of the air duct, the more sound is reflected from the wall, affecting the signal collection of the sound collection element and causing the noise signal detected by the sound collection element to differ significantly from the main wave propagating from the front face in the air duct. Therefore, the sound collection device should be positioned as far away from the air duct wall as possible, that is, on the main path of noise propagation in the air duct. This is also for more accurate and comprehensive noise collection. However, the greater the distance between the sound collection device and the second side wall, the closer the sound collection device is to the side wall, which means that the sound collection device is positioned more accurately. The closer to the central area of the air duct, the greater the flow rate of the air flow adjacent to the central area of the air duct, and the greater the sound collection device is affected by wind noise. For this reason, the distance between the sound collection device and the second side wall needs to select a suitable value range, specifically using the above-mentioned definition: L1 and a satisfy the relationship: 0<L1 / a<0.3. Within this range, it can not only reduce the influence of the reflection of the air duct wall during the sound collection process, but also avoid as much as possible the influence of wind noise due to excessive proximity to the central area of the air duct (the flow rate of the air flow in this area is also greater), while ensuring the comprehensiveness of sound collection, thereby further improving the accuracy of sound collection. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a vertical cross-sectional view of the range hood according to an embodiment of the present invention cut along the front-to-back direction (the fan is placed horizontally);

[0029] Figure 2 This is a vertical cross-sectional view of the air duct portion of the range hood according to an embodiment of the present invention cut along the left-right direction (only one sound collecting device is provided adjacent to the first side wall);

[0030] Figure 3 This is a vertical cross-sectional view of the air duct portion of the range hood according to an embodiment of the present invention cut along the left-right direction (only three sound collecting devices are provided near the first side wall);

[0031] Figure 4 This is a schematic diagram of the three-dimensional structure of the sound collection device according to an embodiment of the utility model;

[0032] Figure 5 This is an exploded view of the sound collection device according to an embodiment of the present utility model;

[0033] Figure 6 A vertical cross-sectional view of the sound collection device according to an embodiment of the present invention taken along the front-to-back direction;

[0034] Figure 7 for Figure 6 The schematic diagram of the structure after omitting the windproof and sound-permeable parts;

[0035] Figure 8 This is a transverse cross-sectional view of the sound collection device according to an embodiment of the present invention cut along the left-right direction;

[0036] Figure 9 Schematic diagram of the sound propagation process at the first sound inlet of the mounting frame;

[0037] Figure 10 This is a vertical cross-sectional view of the range hood according to an embodiment of the present invention cut along the front-to-back direction (the fan is placed vertically). DETAILED DESCRIPTION

[0038] The present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

[0039] In the specification and claims of the present invention, directional terms such as "front," "back," "up," "down," "left," "right," "side," "top," and "bottom" are used to describe various exemplary structural parts and components of the present invention. However, these terms are used herein for convenience of description only and are based on the exemplary orientations shown in the accompanying drawings. Since the embodiments disclosed in the present invention can be arranged in different orientations, these directional terms are intended for illustrative purposes only and should not be construed as limiting. For example, "up" and "down" are not necessarily limited to directions opposite to or consistent with the direction of gravity.

[0040] Figures 1-10The invention shows an installation structure of an active noise reduction system of a range hood and a preferred embodiment of the range hood.

[0041] The active noise reduction system is usually installed in the air duct 10 of the range hood (such as a range hood or a kitchen appliance with a range hood function, such as an integrated stove). The sound collection device is an important part of the active noise reduction system and is also installed in the air duct 10 of the range hood. Taking the range hood as an example, the above-mentioned "air duct 10" can refer to the range hood casing, or it can refer to a box structure with a "channel" for the oil smoke to pass through, such as the channel between the fan system and the range hood of the range hood in a ceiling-mounted range hood. For details, see Figure 1 An active noise reduction system generally includes a sound collection device 1, a speaker, and a controller. The sound collection device 1 includes a sound collection element 11 (typically a microphone). The microphone collects the noise generated by the range hood during operation, and the collected noise waves are transmitted to the controller in the form of electrical signals. The controller analyzes and processes the noise and issues a command to the speaker, controlling it to emit sound waves that match the noise waves to neutralize the noise, thereby achieving a noise reduction effect. The sound collection device of this embodiment can be used to install the sound collection element 11 and provide oil and wind protection.

[0042] The air duct 10 of the range hood extends vertically, and its top is connected to the fan system 90. The fan system 90 can be set in the ceiling. Of course, the fan system 90 can also be set in the air duct 10. The air duct 10 can be formed by the internal space of the fan frame of the range hood. The bottom of the air duct 10 is connected to the smoke hood 61 of the range hood. The air duct 10 includes a first side wall 101 and a second side wall 102 opposite to each other in the front and back (in the first direction) and a third side wall 103 and a fourth side wall 104 opposite to each other in the left and right (in the second direction), wherein the first side wall 101 is located on the front side and the second side wall 102 is located on the rear side. The bottom rear side of the air duct 10 also has an air flow inlet 105 connected to the smoke hood 61. The opening direction of the air flow inlet 105 is upward, that is, consistent with the extension direction of the air duct 10. The rear side of the smoke collecting hood 61 has a vertically extending smoke inlet chamber 611, the top of which is connected to the air inlet 105. The front side of the smoke inlet chamber 611 also has an air inlet 610 for external air to enter.

[0043] The air inlet 105 is positioned adjacent to the first sidewall 101, i.e., positioned toward the rear, while at least one sound collection device is positioned adjacent to the second sidewall 102 of the air duct 10, i.e., positioned toward the front. Specifically, using a plane formed along the extension of the air duct 10 and passing through points in the middle of the air duct 10 in the first direction as a reference plane, the phrase "the air inlet 105 is positioned adjacent to the first sidewall 101, and at least one sound collection device 1 is positioned adjacent to the second sidewall 102" can be understood as meaning that the air inlet and at least one sound collection device 1 are located on opposite sides of the reference plane. Because the airflow velocity in the air duct 10 is higher on the side adjacent to the air inlet 105 in the transverse direction (i.e., the first direction) and lower on the side further from the air inlet 105, positioning the sound collection device on the side further from the air inlet 105, based on the airflow conditions within the air duct 10, can effectively reduce the adverse effects of secondary noise (wind noise) generated by the sound collection device being directly impacted by airflow on the sound collection device, thereby improving sound collection accuracy.

[0044] like Figure 1 As shown, the fan can be placed horizontally. Specifically, the fan 90 includes a volute 91 and an impeller 92 disposed in the volute 91. The axis of the impeller 92 extends vertically, that is, it is consistent with the extension direction of the air duct 10. The center position of the air flow inlet 105 is recorded as point F1, and the center position of the axis of the impeller 92 through the bottom port of the impeller 92 is recorded as point F2. The line between point F1 and point F2 is recorded as line segment F1F2. From the vertical cross-section of the air duct 10 cut along the first direction, the sound collection device 1 is arranged in the area between the line segment F1F2 and the second side wall 102 in the air duct 10. As shown in FIG. Figure 1 As shown, the shortest distance in the first direction between line segment F1F2 and second sidewall 102 is denoted as S1, and the distance between first sidewall 101 and second sidewall 102 of air duct 10 is a. Considering that the airflow along the flow path within the air duct is related to the relative positions of the fan and air inlet in the first direction, and that the sound collection device is positioned adjacent to the second sidewall, the distance between the line connecting the fan and air inlet and the second sidewall needs to be appropriately designed to prevent the sound collection device from being too close to the high-velocity area in the middle of the air duct and being affected by strong wind noise. Specifically, the value range of S1 / a satisfies the following condition: S1 / a ≥ 1 / 10.

[0045] like Figure 10As shown, the fan can also be placed vertically. Specifically, the fan 90 includes a volute 91 and an impeller 92 disposed within the volute 91. The axis of the impeller 92 extends horizontally, specifically aligned with the first direction. The volute 91 includes an annular wall 911 and cover plates 912 connected to both axial ends of the annular wall 911. The axis of the impeller 92 extends horizontally. The center of the air inlet 105 is denoted as point F1, and the center of the bottom of the volute annular wall 911 in its width direction is denoted as point F3. The line connecting points F1 and F3 is denoted as line segment F1F3. In a vertical cross-section of the air duct 10 taken along the first direction, the sound collection device 1 is disposed within the area within the air duct 10 between line segment F1F3 and the second side wall 102. The shortest distance between line segment F1F3 and the second side wall 102 in the first direction is denoted as S2. The distance between the first side wall 101 and the second side wall 102 of the air duct 10 is a. Considering that the airflow condition on the flow path in the air duct is related to the relative positions of the fan and the air inlet in the first direction, and the sound collection device is arranged adjacent to the second side wall, the distance between the line connecting the fan and the air inlet and the second side wall needs to be reasonably designed to avoid the sound collection device being too close to the high flow velocity area in the middle of the air duct and being affected by strong wind noise. Specifically, the value range of S2 / a satisfies the following condition: S2 / a ≥ 1 / 10.

[0046] Considering that the sound propagation in the air duct 10 will be affected by the wall reflection of the side wall of the air duct 10, the closer to the side wall of the air duct 10, the more the sound is reflected by the wall, which affects the accurate collection of the signal by the sound collecting element 11, and causes the noise signal detected by the sound collecting element 11 to be significantly different from the main wave propagated by the array in the air duct 10. Therefore, the sound collecting device should be arranged in an area away from the wall of the air duct 10 as much as possible, that is, arranged on the main path of noise propagation in the air duct 10. Of course, arranging the sound collecting device on the main path of noise propagation in the air duct 10 is also for more accurate and comprehensive noise collection, but the sound collecting device The greater the distance between the sound collecting device and the second side wall 102, the closer the sound collecting device is to the central area of the air duct 10, and the greater the flow rate of the air flow near the central area of the air duct 10, the greater the sound collecting device 1 is affected by wind noise. Therefore, a suitable value range needs to be selected for the distance between the sound collecting device and the second side wall 102. Specifically, in this embodiment, the distance between the first side wall 101 and the second side wall 102 of the air duct 10 is a, and the spacing between the sound collecting device and the second side wall 102 is L1. The relationship between L1 and a satisfies: 0<L1 / a<0.3, and the preferred range is: 0.05<L1 / a<0.25. A plane formed along the extension of the air duct 10 and passing through the middle of the air duct 10 in the first direction is used as a reference plane. The distance between the sound collection device located adjacent to the first side wall 101 and the reference plane is denoted as a1. The relationship a1 and a satisfy the following conditions: 0.2 < a1 / a < 0.5, with a preferred range of 0.25 < a1 / a < 0.35. The "distance between the sound collection device and the second side wall 102" mentioned above should be understood as the distance between the side of the sound collection device farthest from the second side wall 102 and the second side wall 102.

[0047] To prevent vibrations on the second sidewall 102 from being directly transmitted to the sound collection device and affecting the accuracy of the microphone's sound collection, horizontal beams 106 are provided within the air duct 10. These beams 106 extend horizontally and parallel to the first sidewall 101. The sound collection device adjacent to the second sidewall 102 is mounted on these beams 106.

[0048] Considering that the air flow velocity at different locations in the air duct 10 is related to the position of the air inlet 105 of the air duct 10 and the front-to-back dimension of the air inlet 105, the larger the front-to-back dimension of the air inlet 105, the greater the impact of wind noise on the sound collection device at the same location. Therefore, the sound collection device should also be as close to the second side wall 102 as possible, and the above-mentioned L1 value should be appropriately reduced. Similarly, the greater the distance between the center of the air inlet 105 and the first side wall 101, that is, the closer the air inlet 105 is to the air duct, 10, the more the sound collection device at the same position is affected by wind noise, the greater L1 should be appropriately reduced. Specifically, the distance between the side edge of the air inlet 105 adjacent to the first side wall 101 and the first side wall 101 in the first direction is recorded as c. In order to allow the smoke to be smoothly sucked and exhausted through the front air inlet of the air inlet chamber of the smoke hood, the air inlet 105 needs to be arranged as far back as possible. Preferably, the value range of c is: 0<c<50mm, preferably, the value range of c is: 2<c<20mm. The size of the air inlet 105 in the first direction is recorded as c1, where c1, a and L1 meet the following conditions:

[0049] 0.05<L1 / a<0.3, when 1 / 5<c1 / a<1 / 3;

[0050] 0.05<L1 / a<0.25, when 1 / 3≤c1 / a<2 / 3.

[0051] There may be only one sound collecting device provided adjacent to the first side wall 101, or two or more sound collecting devices may be provided. Figure 2 It is shown that only one sound collecting device is provided adjacent to the first side wall 101 to prevent the sound collection from being affected by the reflection of the left and right side walls of the air duct 10. The position of the sound collecting device in the second direction should be reasonably selected. Specifically, the distance between the third side wall 103 and the fourth side wall 104 is denoted as b. There is one sound collecting device provided adjacent to the first side wall 101. The distance between the sound collecting device and the third side wall 103 is denoted as b1, and the distance between the sound collecting device and the fourth side wall 104 is denoted as b2. The following conditions are satisfied among b1, b3, and b: 1 / 5≤b1 / b≤1 / 2; 1 / 5≤b2 / b≤1 / 2.

[0052] Generally, when cooking on one side, the air volume on the left and right sides of the range hood will also be controlled (for example, by changing the ventilation area of the oil grilles of the air inlet on the left and right sides). In this way, the air volume on the left and right sides of the air duct 10 will also be different. In order to eliminate or reduce the adverse effect of the above-mentioned air volume difference on the accuracy of sound collection as much as possible, in another preferred embodiment, two or more sound collection devices can be arranged near the first side wall 101 and dispersed as much as possible, such as Figure 3Three sound collection devices are shown. The three sound collection devices are spaced apart in sequence along the second direction. The distance between the sound collection device adjacent to the third side wall 103 and the third side wall 103 is denoted as b1', and the distance between the sound collection device adjacent to the fourth side wall 104 and the fourth side wall 104 is denoted as b2'. The following conditions are satisfied between b, b1', and b2': 1 / 6 ≤ b1' / b ≤ 2 / 5; 1 / 6 ≤ b2' / b ≤ 2 / 5.

[0053] Considering that the side of the air duct 10 adjacent to the air flow inlet 105 is the main path for noise propagation and contains the most comprehensive information on noise signals, it is also necessary to set more sound collection devices 1 on this path in order to more comprehensively collect noise information in the air duct. In this embodiment, a sound collection device is also provided at a position adjacent to the first side wall 101 in the air duct 10, wherein the sound collection device 1 provided adjacent to the first side wall 10 is recorded as a first sound collection device, and the sound collection device 1 provided adjacent to the second side wall 102 is recorded as a second sound collection device. The number of first sound collection devices is greater than the number of second sound collection devices. Of course, the number of first sound collection devices and the number of second sound collection devices can also be the same.

[0054] The sound collection device of this embodiment includes a sound collection element 11 and a housing 2. The housing 2 defines a sound propagation channel, with the sound collection element 11 located within the channel. The sound collection device is located below the fan system, meaning that the noise generated by the fan system propagates downward along the air duct 10, and the sound collection device is positioned directly along this downward propagation path within the air duct 10. In addition to the housing, the sound collection device also includes an oil-proof, sound-permeable membrane 28 and a windproof, sound-permeable member 30. The housing also includes a mounting bracket 20 and a windshield 40.

[0055] The mounting bracket 20 can be mounted on the side wall or beam of the air duct 10. A receiving slot 21 for receiving the sound collecting element 11 is provided on the front side wall. The front portion of the receiving slot 21 has an opening serving as a first sound inlet 211 for sound to enter the receiving slot 21. The first sound inlet 211 should be understood as an opening for sound from the outside (the sound collecting channel in this embodiment) to enter the receiving slot 21 and be effectively collected by the sound collecting element. Figure 9 The opening defined by the boundary points A1, A2, etc. of the middle receiving groove 21 in the circumferential direction does not necessarily refer to the maximum opening of the front portion of the receiving groove 21.

[0056] The mounting frame 20 also has third mounting portions 263 extending to the left and right, respectively, to expose the exterior of the wind shield 40. A fourth mounting portion 264 extending downward from the bottom of the mounting frame 20 to expose the exterior of the wind shield 40 is also provided. Both the third mounting portion 263 and the fourth mounting portion 264 are screwed to a crossbeam within the air duct 10. A forward-extending connecting post 265 is provided below the receiving slot 21 of the mounting frame 20. The wind shield 40 is connected to the connecting post 265 of the mounting frame 20 via screws 50.

[0057] The wind shield 40 includes a left side wall 411 and a right side wall 412 that are arranged opposite to each other and spaced apart, and a front side wall 413 connected between the front edges of the left side wall 411 and the front edges of the right side wall 412, thereby forming a cover structure with an open rear side. The front side wall 413 of the wind shield 40 is located in front of the receiving slot 21 of the mounting bracket 20. The front side wall 413 of the wind shield 40 has a shape along the direction of airflow in the air duct 10 (such as Figure 6 The guide surface 4130 (in the direction indicated by the hollow arrow) gradually tilts toward the interior of the air duct 10. Specifically, the guide surface 4130 is located at the lower portion of the front side wall 413, that is, at the windward end of the front side wall 413. It tilts forward from bottom to top, while the upper portion of the front side wall 413 extends substantially vertically, facing the portion of the mounting bracket 20 in the front-to-back direction. Along the direction of airflow within the air duct 10, the guide surface 4130 of the wind shield 40 is located upstream of the portion of the mounting bracket 20 in the receiving slot 21. Positioning the guide surface 4130 of the wind shield 40 downward also allows sufficient space within the wind shield 40, opposite the front portion of the receiving slot 21, to accommodate components such as the windproof sound-permeable member 30 and the oil-proof sound-permeable membrane 28.

[0058] In order to improve the oil-proof effect, the windshield 40 of this embodiment can be made of plastic or metal.

[0059] In this embodiment, the windshield 40 and the front side of the mounting frame 20 form a vertically extending gap between them in the front-to-back direction. This gap is open at its upper end (i.e., the end closest to the noise source) and closed at its lower end (i.e., the end further from the noise source). This gap serves as the sound collection channel 200, located on the front side of the mounting frame 20. More specifically, a second sound inlet 45, communicating with the sound collection channel 200, is defined between the leeward end of the windshield 40 (i.e., the portion of the air duct proximal to the range hood's fan system) and the front sidewall of the mounting frame 20. The second sound inlet 45 faces upward in a direction B4. In this embodiment, both the air duct 10 and the sound collection channel 200 extend vertically, meaning that the sound collection channel 200 extends in the same direction B2 as the air duct 10.

[0060] The air duct 10 of this embodiment also extends vertically, that is, the extension direction of the sound collection channel 200 is consistent with the extension direction B2 of the air duct 10. The opening direction B1 of the first sound inlet 211 is perpendicular to the extension direction B3 of the sound collection channel 200.

[0061] The lower section of the sound collection channel 200 is aligned with the first sound inlet 211 at the front of the receiving slot 21 of the mounting bracket 20 in the front-to-back direction. The windscreen 40 effectively prevents high-speed oil smoke airflow from directly impacting the windproof and sound-permeable member 30, significantly reducing oil smoke contamination of the member. Furthermore, when the windscreen 40 is coupled with the mounting bracket 20, only the upper second sound inlet 45 remains, directly isolating noise from the lower airflow and secondary turbulence. This ensures that noise entering the windproof and sound-permeable member 30 primarily originates from above, in the direction of the range hood's primary noise source, thus ensuring accurate noise collection.

[0062] Since the sound collecting element 11 is installed in the receiving groove 21 of the mounting frame 20 and a windshield 40 is provided outside the mounting frame 20, the interference of the airflow in the air duct 10 on the sound collecting element 11 can be effectively isolated, and the oil in the airflow can be prevented from contaminating the sound collecting element 11. At the same time, a windproof and sound-permeable member 30 is provided in the sound collecting channel formed between the mounting frame 20 and the windshield 40, which can effectively reduce the influence of wind noise. Even if a small amount of airflow enters the sound collecting channel 200, the pressure pulsation can be weakened in the windproof and sound-permeable member 30, thereby reducing the influence on the accuracy of the microphone sound collection. Furthermore, considering that the noise in the air duct 10 (mainly originating from the fan system) propagates along the extension direction of the air duct 10 and the propagation direction is opposite to the direction of the airflow in the air duct 10, the sound collection channel 200 is arranged along the extension direction of the air duct so that the second sound inlet 45 of the sound collection channel 200 faces the sound source so as to directly receive the noise. Furthermore, considering that a windproof and sound-permeable member 30 of sufficient length needs to be provided along the sound propagation path to prevent wind noise, thereby reducing the impact of the airflow in the air duct 10 on sound collection, the present embodiment arranges the sound collection channel 200 for accommodating the windproof and sound-permeable member 30 in the extension direction of the air duct 10. This allows the entire sound collection device to be made smaller in the dimension perpendicular to the extension direction of the air duct, i.e., it occupies less space in the air duct 10 of the range hood, thereby reducing the wind resistance at the location of the sound collection device in the air duct 10. Therefore, the stability of the airflow in the air duct 10 is not affected, and the generation of wind noise is also reduced to a certain extent. In this embodiment, the opening direction B1 of the first sound inlet 211 of the receiving groove 21 is perpendicular to the extension direction B3 of the sound collection channel 200. This results in a curved path for the noise in the air duct 10, from the second sound inlet 45 into the sound collection channel 200, and then to the location of the sound collection element 11 in the receiving groove 21. This curved path prevents excessive oil from directly passing through the sound collection channel 200 and coming into contact with the sound collection element 11. Instead, most of the oil adheres to the sidewalls of the sound collection channel 200 or the windproof and sound-permeable member 30. This keeps the sound collection element 11 as far away from the oil as possible, thereby extending the service life of the sound collection element 11. Furthermore, considering that the target noise (primarily from the fan system) that the active noise reduction system needs to collect is low-frequency noise, the sound propagation path within the sound collection device adopts a curved path design. This reduces high-frequency sounds (such as the high-frequency sound portion of wind noise and non-target noise such as high-frequency sound components generated by the fan system) while having a smaller impact on low-frequency sounds. Therefore, it is well suited to the propagation of low-frequency noise within the sound collection device, facilitating its accurate collection by the sound collection element 11. This is mainly because low-frequency noise has a longer wavelength and can better adapt to the bends and irregular shapes of the pipe.When low-frequency noise propagates through curved pipes, it is less likely to be blocked or reflected by the pipe due to its longer wavelength, and therefore can propagate and diffuse better. However, high-frequency noise has a shorter wavelength and is easily reflected and absorbed by the shape and bends of the pipe, making it more difficult for it to propagate and diffuse through the pipe.

[0063] The oil-proof sound-permeable membrane 28 covers the first sound inlet 211 of the receiving slot 21 of the mounting frame 20, specifically at the edge of the front opening of the receiving slot 21. More specifically, to facilitate installation of the oil-proof sound-permeable membrane 28 and ensure a tight seal after installation, the receiving slot 21 has an annular step 210 formed at the edge of the first sound inlet 211. The oil-proof sound-permeable membrane 28 is positioned on this step 210. To ensure the oil-proof performance of the oil-proof sound-permeable membrane 28 while ensuring its effective transmission of sound waves, the membrane 28 in this embodiment is preferably made of a polyethylene film.

[0064] To effectively slow down airflow and eliminate airflow impact, the windproof, sound-permeable member 30 is made of a porous, sound-absorbing material. For example, polyurethane foam or melamine foam can be used, with a porosity greater than 70%. This embodiment's windproof, sound-permeable member 30 not only prevents airflow from impacting the oil-proof sound-permeable membrane 28 and generating additional noise, but also, due to its porous nature, absorbs high-frequency components of sound energy, thereby filtering out noise signals.

[0065] In this embodiment, after the sound collection element 11 is installed in the receiving slot 21 of the mounting frame 20, an oil-proof, sound-permeable membrane 28 is installed at the first sound inlet 211, and a windproof, sound-permeable member 30 is installed outside the first sound inlet 211. Furthermore, a windshield 40 is installed outside the windproof, sound-permeable member 30. This sound collection device utilizes these three layers of protection to effectively eliminate wind noise and prevent oil contamination. After the windshield 40 covers the windproof, sound-permeable member 30, a second sound inlet 45 is reserved at the leeward end, communicating with the outside world. Due to airflow patterns, the flow in the area adjacent to the windproof, sound-permeable member 30 is in a low-speed, high-static-pressure region. The presence of this low-speed, high-static-pressure region reduces wind noise in this region, thereby ensuring that the target noise to be collected (i.e., the noise of the fan system) can be effectively transmitted through the second sound inlet 45 to the receiving slot 21 of the mounting frame 20, thus ensuring the accuracy of noise data collection.

Claims

1. An installation structure for an active noise reduction system of a range fumes extraction device, wherein the active noise reduction system comprises a sound collection device, the sound collection device being arranged in an air duct (10) of the range fumes extraction device, and characterized in that: The air duct (10) comprises a first side wall (101) and a second side wall (102) which are opposite to each other in a first direction, and an air flow inlet (105) for air flow to enter the air duct (10), wherein the first direction is perpendicular to the extension direction of the air duct (10), the air flow inlet (105) is arranged adjacent to the first side wall (101), at least one sound collecting device is arranged adjacent to the second side wall (102), the distance between the first side wall (101) and the second side wall (102) of the air duct (10) is a, the spacing between the sound collecting device and the second side wall (102) is L1, and the relationship between L1 and a satisfies: 0<L1 / a<0.

3.

2. The active noise reduction system installation structure of the range fumes extraction device according to claim 1, characterized in that: A fan (90) is further provided in the air duct (10) of the oil fume extraction device or at the port of the air duct (10). The fan (90) includes a volute (91) and an impeller (92) provided in the volute (91). The axis of the impeller (92) extends vertically. The center position of the air inlet (105) is recorded as point F1. The center position of the bottom port of the impeller (92) passing through the axis of the impeller (92) is recorded as point F2. The line connecting point F1 and point F2 is recorded as line Segment F1F2, the sound collecting device (1) is arranged in the air duct (10) within the area between the line segment F1F2 and the second side wall (102), the shortest distance between the line segment F1F2 and the second side wall (102) in the first direction is recorded as S1, and the distance between the first side wall (101) and the second side wall (102) of the air duct (10) is a, wherein the value range of S1 / a satisfies the following condition: S1 / a≥1 / 10.

3. The active noise reduction system installation structure of the range fumes extraction device according to claim 1, characterized in that: A fan (90) is further provided in the air duct (10) of the oil fume extraction device or at the port of the air duct (10). The fan (90) includes a volute (91) and an impeller (92) provided in the volute (91). The volute (91) includes an annular wall (911) and cover plates (912) connected to both axial ends of the annular wall (911). The axis of the impeller (92) extends horizontally. The center position of the air flow inlet (105) is marked as point F1, and the center position of the bottom of the annular wall (911) in its width direction is marked as point F1. Point F3 is drawn, and the line connecting point F1 and point F3 is recorded as line segment F1F3. The sound collecting device (1) is arranged in the air duct (10) within the region between line segment F1F2 and the second side wall (102). The shortest distance between line segment F1F3 and the second side wall (102) in the first direction is recorded as S2. The distance between the first side wall (101) and the second side wall (102) of the air duct (10) is a, wherein the value range of S2 / a satisfies the following condition: S2 / a≥1 / 10.

4. The active noise reduction system installation structure of the range fumes extraction device according to claim 1, characterized in that: The distance between the side edge of the air flow inlet (105) adjacent to the first side wall (101) and the first side wall (101) in the first direction is recorded as c, and the value range of c is: 0<c<50mm. The size of the air flow inlet (105) in the first direction is recorded as c1, wherein c1, a and L1 satisfy the following conditions: 0.05<L1 / a<0.3, when 1 / 5<c1 / a<1 / 3; 0.05<L1 / a<0.25, when 1 / 3≤c1 / a<2 / 3.

5. The active noise reduction system installation structure of the range fumes extraction device according to claim 1, characterized in that: The direction of the opening of the air flow inlet (105) is consistent with the extension direction of the air duct (10).

6. The active noise reduction system installation structure of the range fumes extraction device according to claim 1, characterized in that: A crossbeam (106) is provided in the air duct (10) and is arranged in a direction parallel to the first side wall (101), and the sound collecting device is arranged on the crossbeam (106).

7. The active noise reduction system installation structure of the range fumes extraction device according to any one of claims 1 to 6, characterized in that: The air duct (10) has a third side wall (103) and a fourth side wall (104) opposite to each other in a second direction, the second direction is perpendicular to the first direction and the extension direction of the air duct (10), the distance between the third side wall (103) and the fourth side wall (104) is recorded as b, there is a sound collecting device arranged adjacent to the first side wall (101), the distance between the sound collecting device and the third side wall (103) is recorded as b1, the distance between the sound collecting device and the fourth side wall (104) is recorded as b2, and b1, b3 and b meet the following conditions: 1 / 5≤b1 / b≤1 / 2; 1 / 5≤b2 / b≤1 / 2.

8. The active noise reduction system installation structure of the range fumes extraction device according to any one of claims 1 to 6, characterized in that: The air duct (10) has a third side wall (103) and a fourth side wall (104) opposite to each other in a second direction, the second direction is perpendicular to the first direction and the extension direction of the air duct (10), the distance between the third side wall (103) and the fourth side wall (104) is recorded as b, there are at least two sound collection devices arranged adjacent to the first side wall (101), each of the sound collection devices is arranged in sequence along the second direction, the distance between the sound collection device adjacent to the third side wall (103) and the third side wall (103) is recorded as b1', the distance between the sound collection device adjacent to the fourth side wall (104) and the fourth side wall (104) is recorded as b2', and b, b1' and b2' satisfy the following conditions: 1 / 6≤b1' / b≤2 / 5; 1 / 6≤b2' / b≤2 / 5.

9. The active noise reduction system installation structure of the range fumes extraction device according to any one of claims 1 to 6, characterized in that: A sound collecting device is also provided in the air duct (10) at a position adjacent to the first side wall (101). The sound collecting device provided adjacent to the first side wall (101) is referred to as a first sound collecting device, and the sound collecting device provided adjacent to the second side wall (102) is referred to as a second sound collecting device. The number of the first sound collecting devices is greater than or equal to the number of the second sound collecting devices.

10. The active noise reduction system installation structure of the range fumes extraction device according to any one of claims 1 to 6, characterized in that: The sound collection device comprises a shell (2) and a sound collection element (11); a sound propagation channel is defined on the shell (2); the sound collection element (11) is arranged in the sound propagation channel; the shell (2) has a second sound inlet (45) for sound in the air supply duct (10) to enter the sound propagation channel; the second sound inlet (45) is located on the leeward side of the shell (2).

11. A range hood comprising an air duct (10) and an active noise reduction system, wherein the active noise reduction system comprises a sound collection device, a speaker, and a controller, wherein the controller receives a noise signal from the sound collection device and generates a noise reduction signal, which is then transmitted to the speaker to emit a noise reduction wave, wherein the sound collection device and the speaker are both disposed in the air duct (10) of the range hood, and wherein: It also includes the active noise reduction system installation structure of the range fumes extraction device according to any one of claims 1 to 10.

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