A range hood

Abstract

The application discloses a kind of range hood, including smoke collecting hood, fan frame and fan, first air inlet and second air inlet are arranged left and right on the smoke collecting hood;Range hood further includes first smoke guide plate and second smoke guide plate;First smoke guide plate and second smoke guide plate are all made into noise reduction plate;First smoke guide plate and second smoke guide plate can at least be in the following two states: closed state, first smoke guide plate closes first air inlet, second smoke guide plate closes second air inlet, so that the end of two smoke guide plates close to each other is the first end of itself, the end of two smoke guide plates away from each other is the second end of itself, each first end is constrained in smoke collecting hood, smoke collecting hood, fan frame and two smoke guide plates jointly constitute first noise reduction cavity;Open state, first smoke guide plate and second smoke guide plate fold to open first air inlet and second air inlet, the second end of each smoke guide plate is located in fan frame, first smoke guide plate and second smoke guide plate jointly constitute second noise reduction cavity.

Description

Technical Field

[0001] This invention relates to an oil fume purification device, and more particularly to an oil fume extractor. Background Technology

[0002] Range hoods have become an indispensable kitchen appliance in modern homes. They operate on the principles of fluid dynamics, using a centrifugal fan inside to draw in cooking fumes and a filter to remove some grease particles. The centrifugal fan consists of a casing, an impeller housed within the casing, and a motor that drives the impeller. As the impeller rotates, a negative pressure is generated at the center of the fan, drawing in the cooking fumes from below. After being accelerated by the fan, the fumes are collected by the casing and guided outdoors.

[0003] Currently, the noise of range hoods mainly comes from aerodynamic noise, mechanical noise, and electromagnetic noise, with aerodynamic noise being the primary source. Aerodynamic noise includes rotational noise and eddy current noise, with rotational noise being the main source. Rotational noise is inevitably generated by the structure itself under high-speed rotation. Simply changing the structure of the fan system itself (such as the trailing edge of the blades, the volute, the impeller disk, the volute profile, etc.) can generally only reduce noise by less than 0.5dB. This is because, to achieve a certain airflow while ensuring performance, a certain rotational speed must be reached. Under high-speed rotation, there will inevitably be rotational noise, and 70% of the noise we hear comes from rotational noise.

[0004] Therefore, a generally better noise reduction measure is to apply passive noise reduction, such as the silent range hood disclosed in Chinese Patent Application No. 201310627547.X. This range hood features a sound-absorbing guide hood positioned directly opposite the volute, with micropores on the hood that provide a certain degree of sound absorption and noise reduction. However, this device is only suitable for single-intake range hoods. For dual-intake range hoods, which typically have two intakes (left and right), each with different airflow rates under different cooking conditions, the noise reduction frequency band covered by the micropores is usually narrower. Furthermore, the airflow speeds at the left and right intakes differ in actual use, and the range hood itself has multiple speed settings. These factors cause variations in airflow speed, resulting in different frequency noise peaks. Reducing the noise of the range hood during cooking can significantly improve the cooking experience. Moreover, one side of the sound-absorbing guide hood faces the flow channel, and the other side faces the kitchen environment. The sound propagates in a spherical shape, spreading outward from the sound source, and can only filter noise once.

[0005] In addition, common kitchen appliances all produce varying degrees of noise, such as dishwashers, refrigerators, microwave ovens, etc. The noise generated by these appliances makes the kitchen environment noisy and affects people's health. However, there is currently no good solution to reduce this kind of noise. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to address the shortcomings of the prior art by providing a range hood that improves the noise level inside the range hood during operation and the noise level in the kitchen when the range hood is not in operation.

[0007] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows: a range hood, comprising a smoke collection hood, a fan frame disposed on the smoke collection hood, and a fan disposed within the fan frame; the smoke collection hood has a first air inlet and a second air inlet arranged left and right; the range hood further comprises a first smoke guide plate and a second smoke guide plate; characterized in that:

[0008] Both the first smoke guide plate and the second smoke guide plate constitute noise reduction plates;

[0009] The first smoke guide plate and the second smoke guide plate can be in at least two of the following states:

[0010] In the closed state, the first smoke guide plate closes the first air inlet, and the second smoke guide plate closes the second air inlet. The ends of the two smoke guide plates that are close to each other are their respective first ends, and the ends of the two smoke guide plates that are far apart from each other are their respective second ends. Each first end is constrained within the smoke collection hood. The smoke collection hood, the fan frame, and the two smoke guide plates together constitute the first noise reduction cavity.

[0011] In the open state, the first smoke guide plate and the second smoke guide plate close together to open the first air inlet and the second air inlet. The corresponding second ends of each smoke guide plate are located inside the fan frame. The first smoke guide plate and the second smoke guide plate together form the second noise reduction cavity.

[0012] Therefore, when the range hood is not in the cooking state, the first noise reduction cavity formed can effectively improve the noise of the kitchen environment; when the range hood is in the cooking state, the second noise reduction cavity formed by the two smoke guide plates can effectively reduce the noise generated when the range hood is working, thus improving the noise inside and outside the range hood.

[0013] Furthermore, to facilitate the formation of the second noise reduction cavity, the first smoke guide plate includes a first smoke guide plate body and a first surrounding plate surrounding the outer peripheral edge of the first smoke guide plate body, and the second smoke guide plate includes a second smoke guide plate body and a second surrounding plate surrounding the outer peripheral edge of the second smoke guide plate body.

[0014] In the closed state, the first smoke guide plate body closes the first air inlet, the second smoke guide plate body closes the second air inlet, and the first enclosure and the second enclosure face inwards towards the fan frame;

[0015] When open, the first enclosure and the corresponding second enclosure abut against each other.

[0016] Furthermore, to facilitate the formation of a noise reduction plate, a first noise reduction hole is provided on the body of the first smoke guide plate, and a second noise reduction hole is provided on the body of the second smoke guide plate, thus forming a noise reduction plate from the smoke guide plates.

[0017] Furthermore, to avoid interference when the two smoke guide plates are flipped over, and to ensure that a sealed cavity is formed when they are closed, the first enclosure plate surrounds the outer peripheral edge of the first smoke guide plate body except for the first end, and the second enclosure plate surrounds the outer peripheral edge of the second smoke guide plate body except for the first end; a bottom plate is provided below the first end of each of the first and second smoke guide plates.

[0018] Furthermore, to facilitate changing the noise reduction frequency, the fan frame is equipped with a frequency converter for changing the noise reduction frequency of the first noise reduction cavity and / or the second noise reduction cavity.

[0019] Furthermore, to facilitate changing the noise reduction frequency, in the open state, the frequency converter is located within the second noise reduction cavity formed by the first smoke guide plate and the second smoke guide plate.

[0020] Furthermore, the frequency converter includes a first adjustment plate, a second adjustment plate, and a flexible deformable ring. The first and second adjustment plates are fixed on opposite sides of the deformable ring, and the deformable ring is fixed near the edge of each adjustment plate. An elastic air cavity is formed inside each adjustment plate and the deformable ring. The deformable ring deforms with the pressure change in the elastic air cavity. The adaptive frequency converter can easily change the noise reduction frequency of the noise reduction cavity.

[0021] Furthermore, the frequency converter includes a first adjusting plate, a second adjusting plate, and a flexible deformable ring. The first adjusting plate is located on the left side of the deformable ring, and the second adjusting plate is located on the right side of the deformable ring. Both adjusting plates are sealed and fixed to the deformable ring. The deformable ring is fixed at the position of each adjusting plate near the edge, and an elastic air cavity is formed inside each adjusting plate and the deformable ring.

[0022] The second noise reduction cavity formed after the first smoke guide plate and the second smoke guide plate are joined together is divided by the frequency converter into a first sub-noise reduction cavity located on the left side of the frequency converter and a second sub-noise reduction cavity located on the right side of the frequency converter.

[0023] Therefore, the second noise reduction cavity is located in the middle of the left and right air ducts, and the two sub-noise reduction cavities are arranged back to back. This makes each sub-noise reduction cavity face one of the air ducts while facing away from the other air duct, so that the noise is filtered multiple times. For example, the fluid noise generated by the left air duct is partially absorbed by the left noise reduction device, and then partially absorbed by the right noise reduction device.

[0024] Furthermore, the frequency converter is rotatably connected to the fan frame or smoke hood, and the rotation axis of the frequency converter is parallel to the rotation axis of each smoke guide plate. Thus, the effective depth of each noise reduction cavity can be changed by rotating the frequency converter to change the noise reduction frequency.

[0025] Furthermore, in order to facilitate the adjustment of the corresponding noise reduction frequency according to the actual noise environment, a first sound sensor is provided on the first smoke guide plate, and a second sound sensor is provided on the second smoke guide plate.

[0026] The range hood also includes a frequency converter drive mechanism for driving the frequency converter to rotate based on signals from two sound sensors.

[0027] Furthermore, the range hood also includes an air duct that connects the fan and the flexible air chamber in the inverter, thereby enabling adaptive frequency conversion noise reduction. It automatically adjusts to the corresponding noise reduction frequency band under different operating conditions of the range hood, reducing noise and improving the cooking experience.

[0028] Furthermore, the fan includes a volute, which includes two spaced-apart cover plates and an annular wall disposed between the two cover plates. One end of the air duct is opened on the inner side of the cover plate, thereby reducing the impact of airflow fluctuations and oil contamination.

[0029] Furthermore, the air duct is equipped with a booster for controlling the pressure applied to the elastic air chamber. Because the fan faces a variety of operating conditions, and the impeller's manufacturing process inherently introduces a degree of dynamic imbalance, both of these factors cause slight fluctuations in the internal air pressure. These pressure fluctuations cause continuous changes in the elastic air chamber, thus reducing the noise reduction effect. By installing the booster, the applied pressure can be stabilized, thereby stabilizing the elastic air chamber and improving the noise reduction effect.

[0030] Preferably, the air duct includes a first branch duct extending between the fan and the booster, and a second branch duct extending between the booster and the frequency converter;

[0031] The booster includes a first pressure sensor for detecting the air pressure at one end of the first branch pipe extending into the booster and a second pressure sensor for detecting the air pressure at one end of the second branch pipe extending into the booster; the booster also includes a booster pump for pressurizing the second branch pipe, a pressure relief pump for depressurizing the second branch pipe, and a processor for controlling the booster pump and the pressure relief pump based on the signals from the two pressure sensors.

[0032] Furthermore, since the range hood is used during cooking, cooking produces a large amount of oil. After long-term use, the air duct is easily blocked by oil, causing the inverter to fail. To address this, the first branch duct is equipped with an elastic film device at its end outside the booster, thus making the first branch duct a sealed duct. The elastic film device includes an elastic film and a housing. The housing is located at the end of the first branch duct and is open on both sides facing the first branch duct and away from the first branch duct. The aforementioned elastic film is located at the opening of the housing away from the first branch duct. The elastic film and the housing together form a deformation cavity, which is in fluid communication with the inside of the first branch duct.

[0033] Furthermore, to ensure good sealing performance of the deformation cavity, the aforementioned sealing interlayer is provided at the location where the elastic membrane is set on the outer shell.

[0034] Furthermore, the range hood also includes an air duct and a pressure booster. The pressure booster includes a pressure pump for pressurizing the air duct, a pressure relief pump for depressurizing the air duct, and a processor for controlling the pressure pump and the pressure relief pump. The air duct is connected to a flexible air chamber. By incorporating the pressure booster, the applied pressure can be stabilized.

[0035] Furthermore, to facilitate adjusting the corresponding noise reduction frequency according to the actual noise environment, a first sound sensor is provided on the first smoke guide plate, and a second sound sensor is provided on the second smoke guide plate. The processor controls the pressurization pump and the depressurization pump based on the signals from the two sound sensors.

[0036] Compared with the prior art, the advantages of this invention are as follows: when the range hood is not in the cooking state, the first noise reduction cavity formed can effectively improve the noise of the kitchen environment; when the range hood is in the cooking state, the second noise reduction cavity formed by the two smoke guide plates closing together can effectively reduce the noise generated by the range hood during operation, thereby improving the noise inside and outside the range hood; the second noise reduction cavity is located in the middle of the left and right air ducts, and the two sub-noise reduction cavities on the left and right are arranged back to back, so that each sub-noise reduction cavity faces one air duct while facing away from the other air duct. This design allows for multiple noise filters, improving noise reduction. By incorporating a frequency converter, the noise reduction frequency can be adjusted based on sound or pressure, thus expanding the noise reduction range and enhancing the overall effect. Connecting the frequency converter's flexible air chamber to the fan allows for adaptive frequency reduction, automatically adjusting to the appropriate noise reduction frequency band under different operating conditions of the range hood, reducing noise and improving the cooking experience. A booster that expands or contracts the frequency converter compensates for changes in fan pressure, noise, or speed setting, ensuring the flexible air chamber remains stable. A stable flexible air chamber translates to a stable noise reduction chamber and excellent noise reduction performance. Attached Figure Description

[0037] Figure 1This is a schematic diagram of the closed state of the range hood according to the first embodiment of the present invention;

[0038] Figure 2 This is a cross-sectional view of the range hood in the closed state according to the first embodiment of the present invention;

[0039] Figure 3 This is a cross-sectional view of the range hood of the first embodiment of the present invention in an intermediate state from the closed state to the open state;

[0040] Figure 4 for Figure 3 An exploded view of the concealed fan and smoke collection hood of a range hood;

[0041] Figure 5 This is a schematic diagram of the range hood in the open state according to the first embodiment of the present invention;

[0042] Figure 6 This is a cross-sectional view of the range hood in the open state according to the first embodiment of the present invention;

[0043] Figure 7 This is a cross-sectional view of the smoke guide plate and frequency converter 5 of the range hood according to the first embodiment of the present invention;

[0044] Figure 8 This is a cross-sectional view of the smoke guide plate and frequency converter 5 of the range hood according to the first embodiment of the present invention (with...). Figure 7 (Different states);

[0045] Figure 9 This is an exploded structural diagram of the inverter 5 of the range hood according to the first embodiment of the present invention;

[0046] Figure 10 This is a schematic block diagram of the air duct and booster of the range hood according to the first embodiment of the present invention;

[0047] Figure 11 and 12 This is a schematic diagram showing the state changes of the elastic film device of the range hood according to the first embodiment of the present invention.

[0048] Figure 13 This is a schematic diagram of the deformation of the elastic film device in the open state of the range hood according to the first embodiment of the present invention;

[0049] Figure 14 This is a schematic diagram of the air duct and booster of the range hood according to the second embodiment of the present invention. Detailed Implementation

[0050] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions.

[0051] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Since the embodiments disclosed in this invention can be arranged in different directions, these terms indicating direction are only for illustration and should not be regarded as limitations. For example, "upper" and "lower" are not necessarily limited to directions opposite to or consistent with the direction of gravity. In addition, features defined with "first" and "second" may explicitly or implicitly include one or more of such features.

[0052] Example 1

[0053] See Figures 1-6 A range hood, specifically a top-mounted range hood, includes a smoke collection hood 1, a fan frame 2 mounted on the smoke collection hood 1, and a fan 3 disposed within the fan frame 2. Preferably, the fan 3 is a centrifugal fan and a dual-inlet fan, with its axis extending in the left-right direction, thereby oriented its two air inlets towards the left and right sides respectively. The fan 3 can be positioned in the middle within the fan frame 2.

[0054] The fume hood 1 has a first air inlet 11 and a second air inlet 12 arranged horizontally, with the first air inlet 11 located to the left of the second air inlet 12. The fume hood 1 can be flat (with a small thickness in the vertical direction), and more preferably, it is flat. Thus, the fumes drawn in through each air inlet directly enter the fan frame 2, unlike common range hoods where the fumes accumulate inside the fume hood 1 before entering the fan frame 2. The range hood also includes a first smoke guide plate 41 for opening and closing the first air inlet 11 and a second smoke guide plate 42 for opening and closing the second air inlet 12.

[0055] The first smoke guide plate 41 includes a first smoke guide plate body 411 and a first surrounding plate 412 surrounding the outer periphery of the first smoke guide plate body 411. The second smoke guide plate 42 includes a second smoke guide plate body 421 and a second surrounding plate 422 surrounding the outer periphery of the second smoke guide plate body 421. Each surrounding plate is flat. The first surrounding plate 412 has at least three surrounding plates respectively surrounding the front and rear sides and the left edge of the first smoke guide plate body 411 (except for the first end, which can be defined below), making the first smoke guide plate 41 a hollow cover. The second surrounding plate 422 has at least three surrounding plates respectively surrounding the front and rear sides and the right edge of the second smoke guide plate body 421 (except for the first end, which can be defined below), making the second smoke guide plate 42 a hollow cover. The first smoke guide plate 41 and the second smoke guide plate 42 are preferably integral structures. A bottom plate 48 is provided below the first ends of the first smoke guide plate 41 and the second smoke guide plate 42, thereby closing the gap between the first ends of the first smoke guide plate 41 and the second smoke guide plate 42.

[0056] The first smoke guide plate 41 and the second smoke guide plate 42 can be in at least two states: a closed state and an open state. In the closed state, the first smoke guide plate 41 and the second smoke guide plate 42 are at their maximum relative angle of extension. The first smoke guide plate 41 closes the first air inlet 11, with the body of the first smoke guide plate 411 flush with the bottom of the first air inlet 11. The first enclosure plate 412 extends beyond the first air inlet 11, so that the first smoke guide plate 41 has an opening on the side facing inwards towards the fan frame 2, presenting a concave shape. The second smoke guide plate 42 closes the second air inlet 12, with the body of the second smoke guide plate 421 flush with the bottom of the second air inlet 12. The second enclosure plate 422 extends beyond the second air inlet 12, so that the second smoke guide plate 42 has an opening on the side facing inwards towards the fan frame 2, presenting a concave shape. This closed state prevents odors from entering the kitchen. Preferably, each smoke guide plate can engage with the smoke collection hood 1. The engagement method can be a common snap-fit ​​connection, etc., and the engagement structure is not shown in the figure. The ends of the first smoke guide plate 41 and the second smoke guide plate 42 that are close to each other are their respective first ends (also the first ends of each smoke guide plate body), and the ends that are far apart from each other are their respective second ends (also the second ends of each smoke guide plate body). Preferably, the first ends of the first smoke guide plate 41 and the second smoke guide plate 42 are rotatably connected to the smoke collection hood 1 via a first rotating shaft 45. The smoke collection hood 1 may include supports 13 respectively provided on the front and rear sides to rotatably support the first rotating shaft 45. In the closed state, the first enclosure plate 412 extends upward from the outer peripheral edge of the first smoke guide plate body 411, and the second enclosure plate 422 extends upward from the outer peripheral edge of the second smoke guide plate body 421.

[0057] In the open state, the first smoke guide plate 41 and the second smoke guide plate 42 flip inside the fan frame 2 and close, located below the fan 3. The first smoke guide plate 41 and the second smoke guide plate 42 can respectively abut against the bottom of the fan 3. At this time, the oil fumes enter the fan frame 2 from the first air inlet 11 and the second air inlet 12. Figure 6 The middle arrow indicates the path of the oil fume flow. The first smoke guide plate 41 and the second smoke guide plate 42 also serve as wall guides, making the airflow smoother and reducing flow losses during the flow channel within the fan frame 2. Since both the first smoke guide plate 41 and the second smoke guide plate 42 include a smoke guide plate body and a surrounding plate, when the first smoke guide plate 41 and the second smoke guide plate 42 are closed, the first surrounding plate 411 and the corresponding second surrounding plate 421 abut against each other, forming a sealed cavity. The first smoke guide plate body 411 has a first noise reduction hole 413, and the second smoke guide plate body 421 has a second noise reduction hole 423.

[0058] The range hood also includes a motion mechanism for driving the first smoke guide plate 41 and the second smoke guide plate 42 to rotate. In this embodiment, the first smoke guide plate 41 and the second smoke guide plate 42 rotate independently. The motion mechanism includes a first drive mechanism 61 for driving one of the first rotating shafts 45 to rotate and a second drive mechanism 62 for driving the other first rotating shaft 45 to rotate. Each drive mechanism is preferably a motor, and the rotation axis of each first rotating shaft 45 extends in the front-rear direction. The first drive mechanism 61 and the second drive mechanism 62 can be mounted on the rear support 13.

[0059] A frequency converter 5 is installed below the fan 3. Preferably, in the initial state, the frequency converter 5 is positioned at the center (middle in the left-right direction) of the fan 3. The frequency converter 5 is rotatably connected to the smoke hood 1 (or fan frame 2) via a second rotating shaft 54. The front and rear ends of the second rotating shaft 54 ​​can respectively engage with the corresponding supports 13. The second rotating shaft 54 ​​is parallel to the first rotating shaft 45. The range hood also includes a frequency converter drive mechanism 63, a first rotating seat 641, and a second rotating seat 642. The frequency converter drive mechanism 63 can be installed on the rear support 13, preferably a motor. The first rotating seat 641 is located on the front side of the frequency converter 5, and the second rotating seat 642 is located on the rear side of the frequency converter 5. Each rotating seat can be disc-shaped. The output shaft of the frequency converter drive mechanism 63 can be fixed at the center of the second rotating seat 642. When the frequency converter drive mechanism 63 is started, it can drive the frequency converter 5 to rotate a certain angle.

[0060] See Figures 7-9The frequency converter 5 includes a first adjusting plate 51, a second adjusting plate 52, and a deformable ring 53. The deformable ring 53 is made of a flexible material, such as rubber, and can achieve elastic deformation by stretching / shortening. The first adjusting plate 51 is located on the left side of the deformable ring 53, and the second adjusting plate 52 is located on the right side of the deformable ring 53. Both adjusting plates are sealed and fixed to the deformable ring 53. After the three are sealed and fixed, the deformable ring 53 can be fixed near the edge of each adjusting plate. Thus, an elastic air cavity 55 is formed inside each adjusting plate and the deformable ring 53. The first adjusting plate 51 and the second adjusting plate 52 are respectively fixed to each rotating seat through the second rotating shaft 54 ​​mentioned above.

[0061] See Figure 13 When the range hood is not in operation, the first smoke guide plate 41 and the second smoke guide plate 42 are closed. Since the first smoke guide plate body 411 and the second smoke guide plate body 421 respectively constitute noise reduction plates, the smoke hood 1, the two smoke guide plates, and the fan frame 2 together constitute the first noise reduction cavity Q1. The volume of the noise reduction cavity is adjusted by the expansion and contraction of the frequency converter 5, that is, the resonant frequency of the noise reduction device is adjusted, thereby effectively improving the noise of the kitchen environment. The adjustment of the frequency converter 5 can be based on the signals collected by the various sound sensors. When the range hood is in operation, the sealed cavity formed by the first smoke guide plate 41 and the second smoke guide plate 42 after they are closed houses the frequency converter 5. This sealed cavity is the second noise reduction cavity Q2. The frequency converter 5 divides the second noise reduction cavity Q2 into a first sub-noise reduction cavity 43 located on the left side of the frequency converter 5 and a second sub-noise reduction cavity 44 located on the right side of the frequency converter 5. The frequency converter 5 can be modified by using the following booster 8.

[0062] The range hood also includes an air duct 7, which connects the fan 3 and the inverter 5 internally. The air duct 7 extends into the inverter 5 from one of its rotating seats and engages with the rotating seat to prevent the air duct 7 from rotating with the inverter 5. The rotating seat also positions the air duct 7 to prevent it from shifting relative to the inverter 5. The fan 3 includes a volute 31 and an impeller (not shown) disposed within the volute 31. The volute 31 includes two spaced-apart cover plates 311 and an annular wall 312 disposed between the two cover plates 311. One end of the air duct 7 opens onto the inner wall of the fan 3, preferably on the inner side of the cover plate 311, because the airflow on the annular wall 312 is affected by the impeller's dynamic imbalance, resulting in greater airflow fluctuations, while the inner side of the cover plate 311 is less affected, and the annular wall 312 has more grease than the cover plate 311. The other end of the air duct 7 extends into the elastic air chamber 55 of the inverter 5.

[0063] According to the Helmholtz resonance silencing principle, the air column inside the orifice and the air inside the cavity form an elastic resonance system. When some noise frequencies of the range hood are the same as the natural frequency of this resonance system, the air column in the orifice resonates and undergoes intense friction with the orifice wall. This friction converts sound energy into heat energy, thus achieving silencing. Based on this principle, the resonant frequency of each independent resonant cavity can be obtained as follows: In the formula, c is the speed of sound, S is the area of ​​the corresponding aperture, V is the volume of the cavity, and L is the effective diameter of the aperture. Based on the resonant frequency formula of the independent resonant cavity, the resonant frequency of the parallel resonant cavity can be derived as follows: In the formula, c is the speed of sound, P is the perforation ratio, and D is the effective depth of the cavity. From this formula, it can be seen that when the perforation ratio P remains constant, the resonant frequency of the sound absorption peak can be controlled by adjusting the effective depth D of the cavity.

[0064] This invention, based on the above principles, involves the following: In the open state, the fan 3 starts, generating air pressure inside. This air pressure is introduced into the elastic air chamber 55 through the air duct 7, causing the elastic air chamber 55 to expand. At this time, the deformable ring 53 is deformed and elongated, and the included angle β between the first adjusting plate 51 and the second adjusting plate 52 increases. (See [reference]). Figure 7 When the elastic air chamber 55 expands, the effective depth of the two noise-reducing chambers decreases. When the range hood's speed is increased, meaning the airflow, air pressure, and wind speed also increase, the elastic air chamber 55 expands further, further reducing the effective depth of the two noise-reducing chambers. Combined with the Helmholtz resonance silencing principle, with the perforation rate remaining constant, the decrease in effective depth leads to an increase in the resonant frequency f. In other words, the resonant frequency f changes with the fan's operating conditions, thus achieving variable frequency control.

[0065] See Figure 6 When the first air inlet 11 and the second air inlet 12 draw in the same amount of fumes, the included angle β between the first adjusting plate 51 and the second adjusting plate 52 is 0, and the two noise reduction chambers are equal, achieving noise reduction in the left and right air ducts (the fan frame 2 is divided into left and right air ducts by the fan 3 and the smoke guide plate). When the range hood is controlled to be in right-side strong suction mode by the switch, the range hood will distribute the airflow from the left air duct to the right air duct through airflow adjustment. At this time, the airflow speed in the left air duct decreases, and the airflow speed in the right air duct increases. Due to the change in airflow speed, the noise frequencies of the left and right air ducts are different. The inverter drive mechanism 63 drives the inverter 5 to deflect to the right, see [link to relevant documentation]. Figure 8 The arrow indicates the rotation direction of the second rotating shaft 54. At this time, the effective depth of the first sub-noise reduction cavity 43 increases, and the effective depth of the second sub-noise reduction cavity 44 decreases. That is, the resonant frequency of the first sub-noise reduction cavity 43 decreases, and the resonant frequency of the second sub-noise reduction cavity increases, so that the air ducts on both the left and right sides can achieve effective noise reduction.

[0066] See Figure 7A first sound sensor 46 is installed on the first smoke guide plate 41, and a second sound sensor 47 is installed on the second smoke guide plate 42, which can monitor the noise frequency in real time. During operation, for example, when the range hood is adjusted to a low flow rate in the left duct and a high flow rate in the right duct, the air velocity in the left duct is low, while the air velocity in the right duct is high. The noise frequencies of the two ducts are different. The first sound sensor 46 and the second sound sensor 47 receive the sound signals, and after judgment by the range hood's control system, adjust the inverter drive mechanism 63 to deflect the inverter 5 to the right. Figure 8 As shown, at this time, the effective depth of the first sub-noise reduction cavity 43 increases, and the effective depth of the second sub-noise reduction cavity 44 decreases, that is, the resonant frequency of the first sub-noise reduction cavity 43 decreases, and the resonant frequency of the second sub-noise reduction cavity increases. When the resonant frequency of one side of the noise reduction cavity matches the peak noise frequency, the position of the adjustment plate on that side is fixed, and then the position of the adjustment plate on the other side is adjusted by pressurization or depressurization (see below) so that the resonant frequency of the noise reduction cavity on the other side also matches the peak noise frequency of the air duct on the other side, thereby achieving effective noise reduction for both the left and right air ducts. By adding the first sound sensor 46 and the second sound sensor 47, different fan operating conditions can be more accurately adapted. In the closed state, each sound sensor is located on the lower surface of the corresponding smoke guide plate body.

[0067] Furthermore, since the fan 3 faces a variety of operating conditions, and the manufacturing process of the impeller dictates a certain degree of dynamic imbalance, both of these factors cause slight fluctuations in the internal air pressure of the fan 3. These pressure fluctuations cause continuous changes in the elastic air chamber 55, thereby reducing the noise reduction effect. Therefore, in this embodiment, see... Figure 10 A booster 8 is provided on the air duct 7, thereby the air duct 7 includes a first branch duct 71 extending between the fan 3 and the booster 8 and a second branch duct 72 extending between the booster 8 and the frequency converter 5.

[0068] The booster 8 includes a first pressure sensor 81, a second pressure sensor 82, a processor 84, a pressurization pump 85, and a pressure relief valve 86. The first pressure sensor 81, processor 84, pressurization pump 85, and second pressure sensor 82 are electrically connected in sequence. The first pressure sensor 81 is located at the end of the first branch conduit 71 extending into the booster 8 and is used to detect the air pressure at the end of the first branch conduit 71 extending into the booster 8. The second pressure sensor 82 is used to detect the air pressure at the end of the second branch conduit 72 extending into the booster 8. The pressurization pump 85 and pressure relief valve 86 are both located at the end of the second branch conduit 7 extending into the booster 8. In the gas flow path, the second pressure sensor 82 is located downstream of the pressurization pump 85 and pressure relief valve 86.

[0069] Since the range hood is used during cooking, which produces a large amount of grease, the air duct 7 is prone to becoming clogged with grease after prolonged use, causing the inverter 5 to malfunction. Therefore, an elastic diaphragm device 9 is provided at the end of the first branch duct 71 outside the booster 8, thus making the first branch duct 71 a sealed duct. (See also...) Figure 11 The elastic film device 9 includes an elastic film 91 and a housing 92. The elastic film 91 is disposed inside the housing 92, which is located at the end of the first branch conduit 71. The housing 92 is open on both sides facing the first branch conduit 71 and away from the first branch conduit 71. The elastic film 91 is disposed at the opening away from the first branch conduit 71. The elastic film 91 and the housing 92 together form a deformation cavity 93, which is in fluid communication with the inside of the first branch conduit 71. A sealing interlayer 94 is disposed at the location of the elastic film 91 on the housing 92 to ensure the sealing of the deformation cavity 93.

[0070] The elastic diaphragm 91 undergoes elastic deformation under air pressure. During operation, after the fan 3 starts, the air pressure inside the fan 3 causes the elastic diaphragm 91 to undergo elastic deformation. This elastic deformation increases the air pressure in the first branch conduit 71, causing the first air pressure sensor 81 to receive a change signal. The processor 84 processes this signal and controls the pressurization pump 85 to start working, thereby causing the elastic air chamber 55 to expand and change through the second branch conduit 72. The second air pressure sensor 82 monitors and feeds back to the pressurization pump 85 in real time for closed-loop feedback, stabilizing the air pressure in the second branch conduit 72. When the air pressure in the second branch conduit 72 is too high, it can be released through the pressure relief valve 86. Thus, the stabilization of the air pressure entering the second branch conduit 72 from the booster 8 indicates the stabilization of the deformation of the elastic air chamber 55, thereby more effectively producing a noise reduction effect.

[0071] Alternatively, the first branch pipe 71 can be omitted, and the required air pressure for each of the three fan speeds can be set at the factory, and the air pressure can be adjusted according to the different speeds.

[0072] Example 2

[0073] See Figure 14 In this embodiment, the difference from the first embodiment is that the end of the first branch conduit 71 is no longer provided with the elastic film device 9, the first branch conduit 71 and the second branch conduit 72 are directly connected and fluidly communicated, the first pressure sensor 81 is still connected to the first branch conduit 71, the second pressure sensor 82, the pressurizing pump 85 and the depressurizing pump 86 are still connected to the second branch conduit 72, so that the first pressure sensor 81 and the second pressure sensor 82 can detect the air pressure at the corresponding position, and the pressurizing pump 85 and the depressurizing pump 86 can change the pressure in the second branch conduit 72.

[0074] The booster 8 also has a one-way valve 83, which is located at the connection between the first branch pipe 71 and the second branch pipe 72 to prevent gas backflow, so that gas can only flow from the first branch pipe 71 to the second branch pipe 72.

[0075] The term "fluid connectivity" as used in this invention refers to the spatial relationship between two components or parts (hereinafter referred to as the first part and the second part, respectively), that is, a fluid (gas, liquid, or a mixture of both) can flow from the first part along a flow path and / or be transported to the second part. This can be a direct connection between the first part and the second part, or an indirect connection between the first part and the second part through at least one third party. This third party can be a fluid channel such as a pipe, channel, conduit, guide, hole, or groove, or a chamber or combination thereof that allows fluid to flow through.

Claims

1. A range hood, comprising a smoke collection hood (1), a fan frame (2) disposed on the smoke collection hood (1), and a fan (3) disposed within the fan frame (2), wherein the smoke collection hood (1) has a first air inlet (11) and a second air inlet (12) arranged to the left and right; the range hood further comprises a first smoke guide plate (41) and a second smoke guide plate (42); characterized in that: Both the first smoke guide plate (41) and the second smoke guide plate (42) constitute noise reduction plates; The first smoke guide plate (41) and the second smoke guide plate (42) can be in at least the following two states: In the closed state, the first smoke guide plate (41) closes the first air inlet (11), and the second smoke guide plate (42) closes the second air inlet (12). The ends of the two smoke guide plates that are close to each other are their respective first ends, and the ends of the two smoke guide plates that are far apart from each other are their respective second ends. Each first end is constrained in the smoke collection hood (1). The smoke collection hood (1), the fan frame (2), and the two smoke guide plates together constitute the first noise reduction cavity (Q1) to reduce the noise in the kitchen environment where the range hood is located. In the open state, the first smoke guide plate (41) and the second smoke guide plate (42) close together to open the first air inlet (11) and the second air inlet (12). The corresponding second ends of each smoke guide plate are located inside the fan frame (2). The first smoke guide plate (41) and the second smoke guide plate (42) together form the second noise reduction cavity (Q2) to reduce the operating noise of the range hood.

2. The range hood according to claim 1, characterized in that: The first smoke guide plate (41) includes a first smoke guide plate body (411) and a first surrounding plate (412) surrounding the outer periphery of the first smoke guide plate body (411). The second smoke guide plate (42) includes a second smoke guide plate body (421) and a second surrounding plate (422) surrounding the outer periphery of the second smoke guide plate body (421). In the closed state, the first smoke guide plate body (411) closes the first air inlet (11), the second smoke guide plate body (421) closes the second air inlet (12), and the first enclosure (412) and the second enclosure (422) face inward towards the fan frame (2); In the open state, the first enclosure (412) and the corresponding second enclosure (422) abut against each other.

3. The range hood according to claim 2, characterized in that: The first smoke guide plate body (411) is provided with a first noise reduction hole (413), and the second smoke guide plate body (421) is provided with a second noise reduction hole (423), so that each smoke guide plate constitutes a noise reduction plate.

4. The range hood according to claim 2, characterized in that: The first enclosure (412) surrounds the outer periphery of the first smoke guide plate body (411) except for the first end, and the second enclosure (422) surrounds the outer periphery of the second smoke guide plate body (421) except for the first end; a bottom plate (48) is provided below the first end of each of the first smoke guide plate (41) and the second smoke guide plate (42).

5. The range hood according to claim 1, characterized in that: The fan frame (2) is equipped with a frequency converter (5) for changing the noise reduction frequency of the first noise reduction cavity (Q1) and / or the second noise reduction cavity (Q2).

6. The range hood according to claim 5, characterized in that: In the open state, the frequency converter (5) is located in the second noise reduction cavity (Q2) formed by the first smoke guide plate (41) and the second smoke guide plate (42).

7. The range hood according to claim 5, characterized in that: The frequency converter (5) includes a first adjustment plate (51), a second adjustment plate (52), and a flexible deformable ring (53). The first adjustment plate (51) and the second adjustment plate (52) are fixed on opposite sides of the deformable ring (53). The deformable ring (53) is fixed near the edge of each adjustment plate. An elastic air cavity (55) is formed inside each adjustment plate and the deformable ring (53). The deformable ring (53) deforms with the pressure change in the elastic air cavity (55).

8. The range hood according to claim 6, characterized in that: The inverter (5) includes a first adjusting plate (51), a second adjusting plate (52), and a flexible deformable ring (53). The first adjusting plate (51) is located on the left side of the deformable ring (53), and the second adjusting plate (52) is located on the right side of the deformable ring (53). Both adjusting plates are sealed and fixed to the deformable ring (53). The deformable ring (53) is fixed at the position of each adjusting plate near the edge. An elastic air cavity (55) is formed inside each adjusting plate and the deformable ring (53). The second noise reduction cavity (Q2) formed by the first smoke guide plate (41) and the second smoke guide plate (42) after being closed is divided by the frequency converter (5) into a first sub-noise reduction cavity (43) located on the left side of the frequency converter (5) and a sub-second sub-noise reduction cavity (44) located on the right side of the frequency converter (5).

9. The range hood according to claim 5 or 6, characterized in that: The frequency converter (5) is rotatably connected to the fan frame (2) or the smoke hood (1), and the rotation axis of the frequency converter (5) is parallel to the rotation axis of each smoke guide plate.

10. The range hood according to claim 9, characterized in that: A first sound sensor (46) is provided on the first smoke guide plate (41), and a second sound sensor (47) is provided on the second smoke guide plate (42); The range hood also includes a frequency converter drive mechanism (63) for driving the frequency converter (5) to rotate according to the signals from the two sound sensors.

11. The range hood according to claim 7 or 8, characterized in that: The range hood also includes an air duct (7) that fluidly connects the fan (3) and the elastic air chamber (55) inside the inverter (5).

12. The range hood according to claim 11, characterized in that: The fan (3) includes a volute (31), which includes two cover plates (311) arranged at intervals and an annular wall (312) disposed between the two cover plates (311). One end of the air duct (7) is opened on the inner side of the cover plate (311).

13. The range hood according to claim 11, characterized in that: The air duct (7) is equipped with a booster (8) for controlling the amount of pressure applied into the elastic air chamber (55).

14. The range hood according to claim 13, characterized in that: The air duct (7) includes a first branch duct (71) extending between the fan (3) and the booster (8) and a second branch duct (72) extending between the booster (8) and the frequency converter (5); The booster (8) includes a first pressure sensor (81) for detecting the air pressure at one end of the first branch conduit (71) extending into the booster (8) and a second pressure sensor (82) for detecting the air pressure at one end of the second branch conduit (72) extending into the booster (8); the booster (8) also includes a booster pump (85) for pressurizing the second branch conduit (72), a pressure relief pump (86) for depressurizing the second branch conduit (72), and a processor (84) for controlling the booster pump (85) and the pressure relief pump (86) according to the signals from the two pressure sensors.

15. The range hood according to claim 14, characterized in that: The first branch conduit (71) is provided with an elastic film device (9) at its end outside the booster (8), thereby the first branch conduit (71) is configured as a sealed conduit. The elastic film device (9) includes an elastic film (91) and a housing (92). The housing (92) is provided at the end of the first branch conduit (71). The housing (92) is open on both sides facing the first branch conduit (71) and away from the first branch conduit (71). The elastic film (91) is provided at the opening of the housing (92) away from the first branch conduit (71). The elastic film (91) and the housing (92) together constitute a deformation cavity (93). The deformation cavity (93) is in fluid communication with the inside of the first branch conduit (71).

16. The range hood according to claim 15, characterized in that: A sealing interlayer (94) is provided at the location where the elastic film (91) is provided on the outer shell (92).

17. The range hood according to claim 7 or 8, characterized in that: The range hood also includes an air duct (7) and a booster (8), the booster (8) including a booster pump (85) for pressurizing the air duct (7), a pressure relief pump (86) for depressurizing the air duct (7), and a processor (84) for controlling the booster pump (85) and the pressure relief pump (86), the air duct (7) being connected to an elastic air chamber (55).

18. The range hood according to claim 17, characterized in that: The first smoke guide plate (41) is provided with a first sound sensor (46), and the second smoke guide plate (42) is provided with a second sound sensor (47). The processor (84) controls the pressurization pump (85) and the depressurization pump (86) according to the signals from the two sound sensors.

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