Air duct components and range hoods

Abstract

The present invention discloses an air duct assembly and a range hood, which belong to the field of household appliance technology and are designed to solve the problems of existing range hoods being relatively thick and having a narrow scope of application. The air duct assembly disclosed in the present invention includes: an air duct housing, on which an air inlet, an internal circulation air outlet and an external circulation air outlet are provided, the air inlet is connected to the external space through the external circulation air outlet, the air inlet is connected to the internal circulation air outlet through the internal circulation air duct, and the internal circulation air outlet is connected to a purification device; two fans are provided in the air duct housing, and the two fans rotate in opposite directions; and two valve plates, each valve plate is provided between a fan and the external circulation air outlet. The air duct assembly and range hood provided by the present invention can select to use the internal circulation working mode or the external circulation working mode as needed, which is flexible and convenient, has low energy consumption and a wide scope of application. By replacing a larger ordinary fan with two smaller fans, the thickness of the air duct housing can be significantly reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of household appliances, and in particular to an air duct component and a range hood. Background Art

[0002] A range hood is a household appliance that uses a fan to generate negative pressure to draw indoor cooking fumes and exhaust them outdoors. To improve extraction efficiency, this typically requires a large motor, which results in a thicker range hood, making it difficult to completely conceal it within a cabinet and affecting the aesthetics of the room. Furthermore, in some situations, direct exhaust of cooking fumes outdoors is undesirable, limiting the applicability of conventional range hoods.

[0003] Some existing range hoods are equipped with a purification device that filters out harmful substances in the fumes and returns the clean air directly to the room. However, purifying all the fumes shortens the life of the purification device and consumes a lot of energy. Summary of the Invention

[0004] The purpose of the present invention is to provide an air duct assembly and a range hood, which can select an internal circulation working mode or an external circulation working mode according to needs, and are flexible and convenient, have low energy consumption, and a small thickness of the entire machine.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] A duct assembly comprises: a duct shell, on which an air inlet, an internal circulation air outlet and an external circulation air outlet are provided, the air inlet is connected to the external space through the external circulation air outlet, the air inlet is connected to the internal circulation air outlet through the internal circulation air duct, and the internal circulation air outlet is connected to a purification device; two fans are provided in the duct shell, and the two fans rotate in opposite directions; and two valve plates, each of the valve plates is provided between one of the fans and the external circulation air outlet, when the valve plate swings to a first position, it can block the external circulation air outlet, and oil smoke can enter the purification device along the internal circulation air duct and the internal circulation air outlet, and execute the internal circulation working mode; when the valve plate swings to a second position, it can block the internal circulation air duct, and oil smoke can be discharged along the external circulation air outlet, and execute the external circulation working mode.

[0007] In one of the preferred embodiments, a partition is provided in the air duct housing, and the partition divides the interior of the air duct housing into two chambers, and each of the chambers is provided with one of the fans.

[0008] In one preferred embodiment, the two valve plates are respectively arranged on both sides of the partition and are respectively connected to the partition.

[0009] In one of the preferred embodiments, reinforcing ribs are provided on the partition.

[0010] In one preferred embodiment, gears are integrally formed on the two valve discs respectively, and the two gears are meshed with each other. One of the two valve discs is in active swinging motion, and the other of the two valve discs is in driven swinging motion.

[0011] In one of the preferred embodiments, the air duct housing includes an integrally formed front plate, a surrounding plate and two volutes, the surrounding plate is bent and extended along the edge of the front plate, the two volutes are respectively arranged in the two chambers, and each volute is provided with a fan.

[0012] In one of the preferred embodiments, the air inlet, the internal circulation air outlet and the external circulation air outlet are respectively opened on the front plate, one end of the volute is tangent to the air inlet, and the other end of the volute is tangent to the enclosure.

[0013] In one of the preferred embodiments, a limiter is provided on the volute for limiting the maximum opening angle of the valve plate.

[0014] In one preferred embodiment, the fan is an axial flow fan.

[0015] In one preferred embodiment, the cross-sectional area of ​​the passage from the air inlet to the outer circulation air outlet gradually increases, and the cross-sectional area of ​​the passage from the air inlet to the inner circulation air outlet gradually increases.

[0016] In one of the preferred embodiments, a guide block with an arc-shaped outer surface is provided inside the air duct housing and at a position next to the external circulation air outlet.

[0017] On the other hand, the present invention adopts the following technical solutions:

[0018] A range hood comprises a range hood housing and the above-mentioned air duct assembly, wherein the air duct assembly is arranged in the range hood housing.

[0019] The duct housing of the air duct assembly provided by the present invention is equipped with an internal circulation vent and an external circulation vent. The valve plate can block either the external circulation vent or the internal circulation duct, allowing users to choose between internal and external circulation modes as needed. This flexible and convenient design features low energy consumption and a wide range of applications. Two smaller fans rotating in opposite directions can replace a single larger conventional fan without compromising performance indicators such as exhaust volume, but the thickness of the duct housing will be significantly reduced.

[0020] The range hood provided by the present invention includes the above-mentioned air duct assembly, and the user can choose to use the internal circulation working mode or the external circulation working mode, which has a wide range of applications; two smaller fans can replace a larger ordinary fan, and performance indicators such as exhaust volume will not be reduced, which is conducive to creating an ultra-thin range hood. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a structural schematic diagram of a range hood provided by a specific embodiment of the present invention;

[0022] Figure 2 is an exploded view of an air duct assembly provided in a specific embodiment of the present invention;

[0023] Figure 3 This is a front view of the air duct housing provided by a specific embodiment of the present invention;

[0024] Figure 4 This is a front view of the air duct housing when the valve plate provides an open external circulation air outlet according to a specific embodiment of the present invention;

[0025] Figure 5 It is a schematic diagram of the partial structure of the air duct housing when the valve plate opens the internal circulation air duct according to a specific embodiment of the present invention;

[0026] Figure 6 This is an exploded view of the combined structure of the air duct housing and the valve plate provided in a specific embodiment of the present invention;

[0027] Figure 7 It is a flow chart of the control method provided by a specific embodiment of the present invention.

[0028] In the picture:

[0029] 1. Air duct housing; 2. Valve plate; 3. Smoke machine housing; 4. Fan; 5. Smoke hood; 6. Air guide plate; 11. Front plate; 12. Air inlet; 13. Volute; 14. External circulation air outlet; 15. Enclosure; 16. Partition; 17. Buckle; 18. Limiting piece; 19. Internal circulation air duct; 141. Guide block; 161. Reinforcement rib. DETAILED DESCRIPTION

[0030] To make the above-mentioned objects, features, and advantages of the present invention more readily apparent, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. The following description sets forth numerous specific details to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art may make similar modifications without departing from the scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0031] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0032] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0033] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediate medium; internal communication between two components, or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0034] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0035] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only implementation methods.

[0036] This embodiment discloses an air duct assembly and a range hood including the air duct assembly, specifically, Figure 1 As shown, the range hood includes a range hood housing 3, and the air duct assembly is arranged in the range hood housing 3. Figures 2 to 6 As shown, the air duct assembly includes an air duct housing 1, two valve plates 2 and two fans 4. The two fans 4 with opposite rotation directions are both arranged in the air duct housing 1. The air duct housing 1 is provided with an air inlet 12, an internal circulation air port (not shown) and an external circulation air port 14. Each valve plate 2 is arranged between a fan 4 and an external circulation air port 14. The valve plate 2 can block one of the external circulation air port 14 and the internal circulation air duct 19. The air inlet 12 is connected to the external space through the external circulation air port 14, realizing the external circulation working mode of exhausting oil fumes; the air inlet 12 is connected to the internal circulation air port through the internal circulation air duct 19, and the internal circulation air port is connected to the purification device, realizing the internal circulation working mode of exhausting oil fumes. The other structures in this range hood are basically the same as those of existing range hoods, and existing devices can be selected according to specific usage.

[0037] When there is no need to filter the oil smoke (for example, the oil smoke contains less impurities and has less pollution to the environment, so it can be discharged directly), the valve plate 2 swings to the second position to block the inner circulation air duct 19, and the oil smoke is directly discharged to the outside through the outer circulation air outlet 14 (such as Figure 4 When the oil smoke needs to be filtered (for example, the oil smoke contains a lot of impurities and it is not suitable to discharge the oil smoke directly into the environment, and the oil smoke needs to be purified), the valve plate 2 swings to the first position to block the external circulation air outlet 14, and the oil smoke passes through the internal circulation air duct 19 (as shown in the curve with arrows in the middle). Figure 5 The air enters the purification device through the internal circulation vent (indicated by the arrowed curve in the middle) and enters the internal circulation mode. The purification device removes impurities from the fume, and the filtered air is directly returned to the room, further protecting the environment. This range hood features both internal and external circulation modes, making it suitable for a wide range of applications. Users can choose between internal and external circulation modes based on their specific needs, providing greater convenience.

[0038] The range hood is provided with two smaller fans 4, which can replace a larger ordinary fan. The performance indicators such as exhaust volume will not be reduced, but the thickness B of the air duct shell 1 will be significantly reduced, which is conducive to creating an ultra-thin range hood. The thickness B can be reduced to below 100 mm.

[0039] One of the two fans 4 rotates clockwise to do work, and the other rotates counterclockwise to do work. The vibrations generated during the rotation of the impellers of the two fans 4 can offset each other, reducing noise while ensuring gas flow, and providing a better user experience.

[0040] To reduce interference between the two fans 4, a partition 16 is provided within the air duct housing 1. The partition 16 divides the interior of the air duct housing 1 into two chambers, each housing a fan 4. This prevents airflow in the two chambers from interfering with each other, preventing turbulence and achieving low noise and effective fume extraction.

[0041] The partition 16 is provided with reinforcing ribs 161 for increasing the load-bearing capacity of the partition 16 , preventing the upright sheet-like partition 16 from being bent, deformed or even broken due to pressure, thereby extending the service life of the range hood.

[0042] Based on the above structure, the two valve plates 2 are respectively arranged on both sides of the partition 16 and are respectively connected to the partition 16. The setting position of the valve plate 2 is more stable, and it is not easy to deviate during the swinging process, and can accurately block the external circulation air outlet 14 or the internal circulation air duct 19.

[0043] The specific installation method of the valve disc 2 is not limited. Preferably, the air duct housing 1 further includes a clip 17 for mounting the valve disc 2. The clip 17 is preferably a hollow tubular structure. The rotating shaft (not shown) of the valve disc 2 is passed through the clip 17, which improves installation efficiency. The valve disc 2 can rotate around the axis of the rotating shaft. During rotation, the spatial position of the valve disc 2 is accurate and stable, and noise is low.

[0044] Based on the above structure, each valve disc 2 is integrally formed with a gear (not shown). The two gears mesh with each other, allowing one valve disc 2 to actively swing while the other valve disc 2 is driven. A drive device is installed only on the actively swinging valve disc 2, which drives the other valve disc 2 via the meshing gears, saving installation space. The two valve discs 2 can operate synchronously, switching between internal and external circulations simultaneously, and achieving more accurate control.

[0045] The rotating shaft of the actively oscillating valve disc 2 is connected to the output shaft of the drive device and rotates synchronously with the output shaft. The drive device is provided with a non-circular retaining groove, and a non-circular retaining portion is formed at the bottom of the rotating shaft. The retaining portion is inserted into the retaining groove. The cooperation between the retaining groove and the retaining portion prevents the rotating shaft from rotating relative to the drive device. The cross-sections of the retaining groove and the retaining portion are preferably D-shaped or polygonal, which is easy to manufacture and effectively prevents relative rotation.

[0046] In order to prevent the two valve discs 2 from moving relative to each other along the axial direction of the rotating shaft, a positioning surface is provided at the end of the rotating shaft of one of the two valve discs 2, and the end of the other rotating shaft abuts against the positioning surface, so that the rotating shafts of the two valve discs 2 are always in a flush state, and the gear transmission between the two valve discs 2 is more stable.

[0047] like Figures 3 to 6 As shown, the air duct housing 1 includes an integrally formed front plate 11, a surrounding plate 15 and two volutes 13. The surrounding plate 15 is bent and extended along the edge of the front plate 11 (extending along the vertical line direction of the front plate 11). The two volutes 13 are respectively arranged in two chambers and are symmetrically arranged. A fan 4 is provided in each volute 13.

[0048] The air duct housing 1 is preferably made of a thermoplastic material such as BMC (Bulk Molding Compound). The material is poured into a mold and then processed and formed. The volute 13 and the enclosure 15 can be seamlessly connected to the front plate 11 to prevent air leakage, increase the negative pressure value in the air duct assembly, and enhance the oil fume absorption capability. The overall strength is good, the weight is light, and the cost is low. The front plate 11, volute 13, and enclosure 15 will not collide with each other due to wind impact, resulting in low noise and long service life. The air duct assembly can be used in range hoods that exhaust gas to the outside through a pipe, or in range hoods that return the treated oil fume gas to the room, and has a wide range of applications.

[0049] A limiter 18 is provided on the volute 13 for limiting the maximum opening angle of the valve plate 2, to avoid the valve plate 2 from opening too large due to control accuracy problems, to avoid the air flow pressure from being too low due to excessive opening of the valve plate 2, and to ensure that the pressure in the air duct housing 1 is always in a good oil fume absorption state.

[0050] The limit member 18 is preferably made of a flexible material, or is wrapped with a damping layer made of a flexible material on the outside (not shown), so as to avoid the valve plate 2 from making an obvious impact sound when it abuts against the limit member 18, and can reduce the reaction force received by the valve plate 2 when it abuts against the limit member 18, thereby extending the service life of the valve plate 2 and reducing the use cost of the range hood.

[0051] A blocking member is provided between the valve plate 2 and the limit member 18. When the valve plate 2 blocks or semi-blocks the external circulation air outlet 14, the blocking member can prevent the oil fume gas from impacting the internal chamber of the air duct shell 1, thereby avoiding the flow loss of the oil fume gas, achieving good oil fume exhaust effect, low noise, and long service life of the air duct assembly and the range hood.

[0052] The blocking member can be made of a flexible material or folded from a sheet material (similar to the folding method of an accordion, or called a parallel folding method). When the valve plate 2 blocks or semi-blocks the external circulation air outlet 14, the blocking member can be stretched or unfolded, blocking between the valve plate 2 and the limit member 18; when the valve plate 2 fully opens the external circulation air outlet 14, the blocking member is completely retracted, and the valve plate 2 abuts against the limit member 18.

[0053] The blocking member is preferably formed by folding a relatively thin sheet, and its total height after folding is relatively small. When the valve plate 2 fully opens the external circulation air outlet 14, the blocking member is completely bent or folded along the crease on its surface and hidden behind the valve plate 2, without affecting the valve plate 2's contact with the stopper 18.

[0054] Based on the above structure, two air inlets 12, an internal circulation air outlet, and an external circulation air outlet 14 are respectively provided on the front plate 11. One end of the volute 13 is tangent to the air inlet 12, and the other end of the volute 13 is tangent to the enclosure 15. The specific location of the internal circulation air outlet is not limited. The location of the purification device can be determined based on the working scenario, and then the internal circulation air outlet can be located near the purification device, which is more convenient to use and more flexible in design.

[0055] Taking into account that the centrifugal fan in an ordinary range hood will send the oil smoke directly to the top of the air duct shell 1, the internal circulation air outlet can only be set at the top of the air duct shell 1. The fan 4 in this embodiment adopts an axial flow fan, and the internal circulation air outlet can be set at any position on the front panel 11. The design scheme is more flexible and more convenient to use.

[0056] On the basis of the above structure, a guide block 141 with an arc-shaped outer surface is provided in the air duct housing 1 and located next to the outer circulation air outlet 14. Figure 4 As shown, when oil smoke approaches the external circulation air outlet 14, it changes its flow path along the outer surface of the guide block 141. Compared to rushing directly toward the external circulation air outlet 14 along the inner wall of the air duct housing 1, the oil smoke that has been redirected by the guide block 141 is more likely to pass through the external circulation air outlet 14, is less likely to cause turbulence at the external circulation air outlet 14, and has higher oil smoke exhaust efficiency.

[0057] In order to reduce wind resistance and noise, the cross-sectional area of ​​the passage from the air inlet 12 to the outer circulation air outlet 14 gradually increases, and the cross-sectional area of ​​the passage from the air inlet 12 to the inner circulation air outlet gradually increases.

[0058] like Figure 3 and Figure 5 As shown, the specific shape of the volute 13 is related to the value of the tension A (the maximum distance between the air inlet 12 and the volute 13). The tension A can be calculated or obtained from a table based on design standards such as the "General Fan Design Manual" and relevant references:

[0059] A=Q / Bc3u, where c3u=(0.65-0.75)c2u. c2u can be found in design standards such as the "General Fan Design Manual" and related references. Q is the flow requirement of the fan system design, and B is the width of the air duct housing 1. The specific value of B is preferably determined according to the height of the impeller used.

[0060] After obtaining the tension A, the unequal-sided basis algorithm can be used to obtain the curved shape of the volute 13. The specific calculation method is not limited, and any method in the prior art that calculates the curved shape of the volute 13 by means of the tension A can be used. Explanation of the unequal-sided basis algorithm: The volute 13 is composed of four arc segments connected end to end, and a coordinate system is formed with the center of the air inlet 12 as the point (0, 0). The coordinates of the center of the first arc segment are (X1, Y1), the coordinates of the center of the second arc segment are (X2, Y2), the coordinates of the center of the third arc segment are (X3, Y3), and the coordinates of the center of the fourth arc segment are (X4, Y4). |X1|≠|X2|≠|X3|≠|X4|, |Y1|≠|Y2|≠|Y3|≠|Y4|.

[0061] In this embodiment, the half-width C value of the external circulation air outlet 14 is ∈ [120mm, 140mm], the tension A ∈ [105mm, 115mm], and the width B of the air duct shell 1 is within the range of 100mm±5mm. The width B of the air duct shell 1 is reduced without sacrificing performance indicators, thereby realizing an ultra-thin design of the range hood.

[0062] like Figure 1 As shown, a smoke collecting hood 5 is provided at the bottom of the range hood housing 3, and an upward concave curved air guide plate 6 is slidably installed at the bottom of the smoke collecting hood 5. When sucking oil smoke, the air guide plate 6 is extended to increase the smoke collecting area; after sucking oil smoke, the air guide plate 6 is reset to reduce the space occupied by the range hood and make the appearance more beautiful.

[0063] The tangent of the edge of the air guide plate 6 is inclined downward or even vertically downward. When the oil smoke rises upward, it will hit 6 and move along the bottom surface of the air guide plate 6. At the edge of the air guide plate 6, the oil smoke will not all overflow directly outside the air guide plate 6. Most of the oil smoke is still in the smoke collection area of ​​the air guide plate 6. The oil smoke collection effect is good and the oil smoke is absorbed more thoroughly.

[0064] A sliding connection (not shown) is provided between the air deflector 6 and the smoke hood 5, and the user can manually push and pull the air deflector 6 to extend and reset the air deflector 6. Alternatively, a motor can be provided on the smoke hood 5, and a motor telescopic rod can be connected to the air deflector 6 to drive the air deflector 6 to move, which is more convenient and labor-saving.

[0065] like Figures 2 to 5 As shown, the range hood is not limited to executing only the internal circulation working mode or the external circulation working mode. The valve plate 2 can also be located between the external circulation air port 14 and the internal circulation air duct 19, that is, the valve plate 2 does not completely block the external circulation air port 14 and the internal circulation air duct 19. A part of the oil smoke is discharged through the external circulation air port 14, and the other part enters the purification device after passing through the internal circulation air duct 19 and the internal circulation air port. This reduces the loss of the purification device while ensuring that the ambient air is not polluted, thereby extending the service life of the purification device.

[0066] like Figure 7 As shown, the control method based on the range hood includes the following steps:

[0067] Step S1: derive a cooking prediction model based on the type of ingredients and the water level in the cooking utensil. Specifically, the type of cooking utensil is first identified. For example, a shallow pot is typically only used for frying and stir-frying, not steaming, while a steamer is typically not used for frying or stir-frying. Identifying the type of cooking utensil helps determine the concentration of cooking fume. An image sensor then captures the water level and the type of ingredients within the cooking utensil. Combined with the type of cooking utensil, a detection device is used to detect temperature changes within the cooking utensil. These parameters are then combined to determine the cooking prediction model (or cooking method, including but not limited to frying, stir-frying, deep-frying, boiling, steaming, and stewing) for the ingredient.

[0068] Step S2: Determine a cooking recipe based on the ingredient type and the cooking prediction model. Specifically, the control device pre-stores a table that corresponds to the cooking prediction model and cooking recipes. By looking up the table, the corresponding cooking recipe can be obtained based on the cooking prediction model. To prevent misjudgment, after the control device automatically obtains the cooking recipe, it can prompt the user for manual confirmation. The cooking recipe may include, but is not limited to, the color of the cooking ingredients corresponding to each dish at each stage (which can be simply divided into early cooking, mid-cooking, and late cooking), the time required for each stage, and the amount of oil smoke generated.

[0069] Step S3: determining the cooking stage according to the cooking recipe, the color of the cooking ingredients and the cooking time.

[0070] Step S4: Different cooking stages typically correspond to different amounts of oil smoke. The control device can preset the ideal opening angle of valve plate 2 for each stage of cooking. The control device then adjusts the opening angle of valve plate 2 based on the preset angle to achieve the desired flow rate in the exhaust duct. The specific actuation method for valve plate 2 is not limited; it suffices to adjust the spatial orientation of valve plate 2 to change the cross-sectional area of ​​the open portion of the exhaust duct. The two valve plates 2 can be controlled in conjunction or independently, without affecting their function.

[0071] Among common cooking methods, frying and stir-frying generate the most oil smoke, so the maximum valve plate 2 opening angle is required. The valve plate 2 opening angles corresponding to the three stages are X, Y, and Z, respectively. These three angles are set as preset angles, and the valve plate 2 opening angles for the remaining cooking methods are adjusted based on this. Frying and stewing generate relatively less oil smoke, so the valve plate 2 opening angles for the three stages are adjusted to 0.5X, 0.5Y, and 0.5Z based on the preset angles. Steaming and boiling produce almost no oil smoke, only some steam, so the valve plate 2 opening angles for the three stages are adjusted to 0.3X, 0.3Y, and 0.3Z based on the preset angles.

[0072] For example, if the selected recipe is stir-fried squid and the corresponding cooking method is stir-frying, the valve plate 2 opening angles corresponding to the initial, middle, and final cooking stages are 10°, 20°, and 8°, respectively. For another example, if the selected recipe is boiled crab and the corresponding cooking method is boiling, the valve plate 2 opening angles corresponding to the initial, middle, and final cooking stages are 3°, 6°, and 2.4°, respectively.

[0073] Step S5: Set the oil fume concentration limit D in the control device. The specific value of the oil fume concentration limit D is not limited and can be preset in the control device or customized by the user based on usage requirements. The reason for setting the oil fume concentration limit D is that the amount of oil fume produced during actual cooking may differ from that in the prediction model. Furthermore, the environment and age of the range hood may result in the valve plate 2 not being able to properly exhaust oil fumes when opened to the ideal angle, or excessive energy consumption. Therefore, it is necessary to set the oil fume concentration limit D and monitor the actual amount of oil fume.

[0074] Step S6: After a set time (for example, ten seconds) after the valve plate 2 opens according to the preset angle, the smoke sensor collects the current smoke concentration information. If the current smoke concentration is less than or equal to the oil smoke concentration limit D, go to step S7; if the current smoke concentration is greater than the oil smoke concentration limit D, go to step S8.

[0075] Step S7: The valve plate 2 maintains the current opening angle. Before the current cooking phase of the current recipe ends, the smoke density information may no longer be detected, or the process may proceed to step S6 after a set time interval.

[0076] Step S8: Increase the opening angle of the valve plate 2, and then go to step S6. The value of each increase in the opening angle of the valve plate 2 is not limited, and can be, but is not limited to, 3°.

[0077] It should be noted that the air duct assembly is not limited to the case where two fans 4 are provided in the air duct housing 1. Even when only one fan 4 is provided in the air duct housing 1, both internal and external circulation operating modes can be achieved. Specifically, the air duct housing 1 includes an air inlet 12, an internal circulation air outlet, and an external circulation air outlet 14, with a valve plate 2 disposed between the internal circulation air outlet and the external circulation air outlet 14. When the valve plate 2 blocks the internal circulation air outlet and opens the external circulation air outlet 14, the oil smoke is discharged directly from the external circulation air outlet 14, executing the external circulation operating mode. When the valve plate 2 blocks the external circulation air outlet 14 and opens the internal circulation air outlet, the oil smoke passes through the internal circulation air outlet and enters the purification device, executing the internal circulation operating mode.

[0078] An outer circulation limiting step (not shown) is provided at the edge of the outer circulation air outlet 14. When the range hood adopts the inner circulation working mode, the edge of the valve plate 2 can abut against the outer circulation limiting step. An inner circulation limiting step (not shown) is provided at the edge of the inner circulation air outlet. When the range hood adopts the outer circulation working mode, the edge of the valve plate 2 can abut against the inner circulation limiting step. The outer circulation limiting step and the inner circulation limiting step can respectively limit the valve plate 2 to prevent the valve plate 2 from swinging excessively; they can also support the valve plate 2 to prevent the valve plate 2 from moving due to the impact of oil smoke, ensuring that the spatial position of the valve plate 2 is more accurate.

[0079] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments, and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. An air duct assembly, characterized in that: include: An air duct housing (1) is provided with an air inlet (12), an internal circulation air outlet, and an external circulation air outlet (14); the air inlet (12) is connected to the external space through the external circulation air outlet (14); the air inlet (12) is connected to the internal circulation air outlet through an internal circulation air duct (19); and the internal circulation air outlet is connected to a purification device; Two fans (4) are arranged in the air duct housing (1), and the two fans (4) rotate in opposite directions; and Two valve plates (2), each valve plate (2) is arranged between one of the fans (4) and the external circulation air outlet (14); when the valve plate (2) swings to a first position, it can block the external circulation air outlet (14), and the oil smoke can enter the purification device along the internal circulation air duct (19) and the internal circulation air outlet, and execute the internal circulation working mode; when the valve plate (2) swings to a second position, it can block the internal circulation air duct (19), and the oil smoke can be discharged along the external circulation air outlet (14), and execute the external circulation working mode; A partition (16) is provided in the air duct housing (1), and the partition (16) divides the interior of the air duct housing (1) into two chambers, and each chamber is provided with one of the fans (4); The two valve plates (2) are respectively arranged on both sides of the partition plate (16) and are respectively connected to the partition plate (16).

2. The air duct assembly according to claim 1, characterized in that: The partition (16) is provided with reinforcing ribs (161).

3. The air duct assembly according to claim 1, characterized in that: Gears are integrally formed on the two valve discs (2), the two gears are meshed with each other, one of the two valve discs (2) is actively swung, and the other of the two valve discs (2) is driven to swung.

4. The air duct assembly according to claim 1, characterized in that: The air duct housing (1) comprises an integrally formed front plate (11), a surrounding plate (15) and two volutes (13); the surrounding plate (15) is bent and extended along the edge of the front plate (11); the two volutes (13) are respectively arranged in the two chambers; and one fan (4) is arranged in each volute (13).

5. The air duct assembly according to claim 4, characterized in that: The air inlet (12), the internal circulation air outlet and the external circulation air outlet (14) are respectively opened on the front plate (11); one end of the volute (13) is tangent to the air inlet (12); and the other end of the volute (13) is tangent to the enclosure (15).

6. The air duct assembly according to claim 4, characterized in that: The volute (13) is provided with a limiting member (18) for limiting the maximum opening angle of the valve plate (2).

7. The air duct assembly according to any one of claims 1 to 6, characterized in that: The fan (4) is an axial flow fan.

8. The air duct assembly according to any one of claims 1 to 6, characterized in that: The cross-sectional area of ​​the passage from the air inlet (12) to the outer circulation air outlet (14) gradually increases, and the cross-sectional area of ​​the passage from the air inlet (12) to the inner circulation air outlet gradually increases.

9. The air duct assembly according to any one of claims 1 to 6, characterized in that: A guide block (141) having an arc-shaped outer surface is provided in the air duct housing (1) and at a position next to the external circulation air outlet (14).

10. A range hood, comprising a range hood housing (3), characterized in that: It also includes an air duct assembly according to any one of claims 1 to 9, and the air duct assembly is arranged in the range hood housing (3).

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