Air duct assembly and range hood

Abstract

The invention relates to the technical field of household appliances, and provides an air duct assembly and a range hood. The air duct assembly comprises an air duct shell, a main flow channel and a guide flow channel are arranged in the air duct shell, one end of the guide flow channel is communicated with the main flow channel, the other end of the guide flow channel is an air outlet, the inner wall of the guide flow channel is an arc-shaped face, and the arc-shaped face is used for guiding airflow so that the airflow can form the coanda effect at the air outlet. According to the air duct assembly provided by the invention, the inner wall of the guide flow channel is arranged to be the arc-shaped surface, so that high-speed airflow in the air duct assembly forms a coanda effect at the air outlet, the high-speed airflow ejected from the air outlet can generate an ejection effect, and the high-speed airflow can carry and mix lampblack generated during cooking, so that the lampblack guide effect is achieved; therefore, the probability of oil smoke leakage and escape is reduced.

Description

Technical Field

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

[0002] In the related art, the air duct assembly of the range hood generates an air curtain airflow that blows obliquely downward toward the cook between the cook and the range hood, thereby limiting the oil smoke to the area between the air curtain airflow and the pot, preventing the oil smoke from rising and approaching the cook's face and being inhaled or escaping, thereby reducing the chance of the cook inhaling the oil smoke. This air curtain can, to a certain extent, isolate the oil smoke rising upward from the pot, preventing the oil smoke from spreading toward the face of the cook and being inhaled. However, if the structure of the air duct assembly is improperly designed, or the installation position of the air duct assembly on the range hood is improper, the air curtain airflow generated by the air duct assembly is easy to blow away the oil smoke and cause it to spread. In addition, the direction of the air curtain airflow is related to the opening and closing angle of the opening and closing plate of the range hood. If the angle of the opening and closing plate is improperly adjusted, the air curtain airflow will also cause the oil smoke to spread, and the cooking environment for the cook cannot be improved. Summary of the invention

[0003] The present application aims to solve at least one of the technical problems existing in the related art. To this end, the present application provides an air duct assembly, which can guide the oil smoke by changing the inner wall structure of the air duct assembly, thereby reducing the probability of oil smoke leakage and escape.

[0004] The present application also provides a range hood.

[0005] The air duct assembly provided in this application includes:

[0006] An air duct shell has a main flow channel and a guide flow channel, one end of the guide flow channel is connected to the main flow channel, the other end of the guide flow channel is an air outlet, the inner wall of the guide flow channel is a curved surface, and the curved surface is used to guide the airflow so that the airflow forms a Coanda effect at the air outlet.

[0007] According to the air duct assembly provided by the present application, by setting the inner wall of the guide flow channel to an arc-shaped surface, the high-speed airflow in the air duct assembly forms a Coanda effect at the air outlet. The high-speed airflow ejected from the air outlet will produce an induced effect, and the high-speed airflow can carry and mix the oil smoke generated during cooking to the main smoke outlet of the range hood for discharge, playing a guiding role for the oil smoke, thereby reducing the probability of oil smoke leakage and escape.

[0008] According to one embodiment of the present application, the structure of the air duct housing at the guide flow channel includes a first side wall and a second side wall, the first side wall is opposite to and spaced from the second side wall, and the guide flow channel is located between the first side wall and the second side wall;

[0009] The arc surface is arranged on a side of the first side wall facing the second side wall.

[0010] According to one embodiment of the present application, the surface of the second side wall facing the first side wall is an arc-shaped surface;

[0011] Alternatively, the second side wall is L-shaped or J-shaped.

[0012] According to an embodiment of the present application, the airflow enters the guide channel along a first direction, and a direction perpendicular to the first direction is a second direction.

[0013] In the first direction, the second side wall has a first end and a second end, the second end deviates from the first end in the second direction, and the vertical distance of the second end deviation in the second direction is L1;

[0014] In the first direction, the first side wall has a third end and a fourth end, the fourth end deviates from the first end in the second direction, and the vertical distance of the deviation of the fourth end in the second direction is L2, wherein L2>L1.

[0015] According to one embodiment of the present application, L2 is less than or equal to six times L1.

[0016] According to an embodiment of the present application, in the direction from the first side wall to the second side wall, the minimum width of the main channel is B1, the minimum distance between the second end and the first side wall is B2, and B2≤B1.

[0017] According to one embodiment of the present application, the value range of B1 is 2mm-5mm.

[0018] According to one embodiment of the present application, the guide channel is arc-shaped, L-shaped, or J-shaped.

[0019] According to one embodiment of the present application, the guide flow channel is a closed flow channel or an open flow channel at the air outlet.

[0020] According to one embodiment of the present application, the guide flow channel has a necking section at the air outlet, and the cross-sectional area of ​​the necking section gradually decreases in the direction of airflow flow.

[0021] According to an embodiment of the present application, the main flow channel includes a first flow channel section and a second flow channel section that are sequentially connected, the second flow channel section is connected to and communicates with the guide flow channel, and the second flow channel section is a straight section.

[0022] According to one embodiment of the present application, the first flow channel section is trumpet-shaped.

[0023] According to one embodiment of the present application, the air duct assembly further includes:

[0024] A fan, the fan is used to drive airflow to flow toward the main channel;

[0025] A fan housing is provided, wherein the fan housing covers the fan and is connected and communicated with an air duct housing.

[0026] According to an embodiment of the present application, the fan housing and the air duct housing are integrally formed;

[0027] Alternatively, the fan housing is spliced ​​and connected to the air duct housing.

[0028] The range hood provided in this application comprises:

[0029] A chassis, wherein the chassis is provided with a smoking port;

[0030] An opening and closing plate, the opening and closing plate is flippably arranged on the chassis, the opening and closing plate is suitable for covering or opening the smoking port, and the opening and closing plate is provided with an air inlet;

[0031] The air duct assembly is the above-mentioned air duct assembly, and the air duct assembly is arranged on the side of the opening and closing plate facing the smoking port, and the air inlet end of the air duct assembly is aligned with the air inlet.

[0032] The range hood provided in the present application includes the above-mentioned air duct assembly and thus has the beneficial effects of the above-mentioned air duct assembly, which will not be described in detail here.

[0033] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related technologies, the drawings required for use in the embodiments or the related technical descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0035] Figure 1 It is a structural schematic diagram of a range hood and an air duct assembly in the related art;

[0036] Figure 2 It is a schematic diagram of the direction of the oil smoke guided by the air duct assembly provided by the present application when working;

[0037] Figure 3 It is a structural schematic diagram of the range hood and air duct assembly provided by the present application;

[0038] Figure 4 It is a schematic diagram of the structure of the air duct assembly provided by this application;

[0039] Figure 5 It is a partial structural schematic diagram of the air duct assembly provided by this application;

[0040] Figure 6 yes Figure 5 A local enlarged view of point A in FIG.

[0041] Figure 7 It is a schematic diagram of the airflow direction of the air duct assembly provided in this application;

[0042] Figure 8 is a schematic diagram of air flow direction of another air duct assembly provided in the present application;

[0043] Fig. 9 is a partial structural schematic diagram of another air duct assembly provided by the present application, wherein the second side is L-shaped, and the guide flow channel is an open flow channel;

[0044] Fig.10 is a partial structural schematic diagram of another air duct assembly provided by the present application, wherein the second side is L-shaped, and the guide flow channel is a closed flow channel;

[0045] Fig.11 It is a schematic diagram of the guiding flow direction of oil smoke by the air duct assembly provided by the present application when working, wherein the guiding flow channel is an open flow channel;

[0046] Fig.12 It is a schematic diagram of the guiding flow direction of oil smoke by the air duct assembly provided in the present application when working, wherein the guiding flow channel is a closed flow channel.

[0047] Fig.13 It is an exploded view of the air duct assembly provided in this application.

[0048] Reference numerals:

[0049] 10. Air duct components;

[0050] 100. Air duct housing;

[0051] 110, main flow channel; 111, first flow channel; 112, second flow channel;

[0052] 120, guide channel; 121, first side wall; 122, second side wall; 123, first end; 124, second end; 125, third end; 126, fourth end; 127, necking section;

[0053] 130. Air outlet;

[0054] 200, fan housing; 201, fan;

[0055] 20. Opening and closing plate; 21. Air inlet;

[0056] 30. Chassis; 31. Smoking opening. DETAILED DESCRIPTION

[0057] The following is a further detailed description of the implementation of the present application in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present application but cannot be used to limit the scope of the present application.

[0058] In the description of the embodiments of the present application, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the embodiments of the present application. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0059] In the description of the embodiments of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances.

[0060] In the embodiments of the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0061] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiments of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0062] like Figure 1 As shown, in the related art, by placing the fan 201' of the air duct assembly 10' in the range hood above the opening and closing plate 20', the air is discharged through the air duct assembly 10' of the range hood to form an air curtain, and by generating an air curtain airflow obliquely downwardly blowing toward the cook between the cook and the range hood, the oil smoke is confined to the area between the air curtain airflow and the cookware, preventing the oil smoke generated by cooking from rising and approaching the cook's face and being inhaled or escaping by the cook, thereby reducing the probability of the cook inhaling oil smoke. However, this structure combining the air duct assembly 10' with the range hood has high requirements on the blowing angle of the airflow and the relative position between the cookware and the airflow, and the cook needs to adjust the position of the opening and closing plate 20' to adjust the blowing angle of the airflow. If the angle of the opening and closing plate 20' is not adjusted properly, the blowing airflow will cause the oil smoke to spread, and the cooking environment of the cook cannot be improved.

[0063] like Figure 2 and Figure 3 As shown, an air duct assembly 10 provided according to an embodiment of the present application includes an air duct housing 100. It should be noted that the air duct assembly 10 can be used in a range hood. For example, the air duct assembly 10 can be installed on the inner side of the opening and closing plate of the range hood. When the range hood is working, the opening and closing plate is opened, and the air duct assembly 10 can emit a high-speed airflow. According to Bernoulli's principle, a negative pressure area will be formed around the high-speed airflow, thereby producing an induced effect, which can carry and mix the oil smoke generated during frying and blow it to the smoke outlet 31 of the range hood for discharge, thereby reducing the probability of oil smoke leakage and escape.

[0064] Specifically, Figure 4As shown, the air duct housing 100 has a main channel 110 and a guide channel 120. The main channel 110 can guide and distribute the airflow so that the pressure distribution in the main channel 110 is more uniform. One end of the guide channel 120 is connected to the main channel 110, and the other end of the guide channel 120 is an air outlet 130. The inner wall of the guide channel 120 is a curved surface. It should be noted that when the fluid flows through the surface of an object with a curvature, the fluid will generate friction with the surface of the object, so that the fluid will deviate from the original flow direction and flow along the protruding surface of the object instead. Therefore, the curved surface can guide the airflow to flow in the direction of the curved surface, so that the airflow forms a Coanda effect at the air outlet 130.

[0065] According to the air duct assembly 10 provided by the present application, by setting the inner wall of the guide flow channel 120 to be an arc-shaped surface, the high-speed airflow in the air duct assembly 10 forms a Coanda effect at the air outlet 130. The high-speed airflow ejected from the air outlet 130 will produce an ejection effect, and the high-speed airflow can carry and mix the oil smoke generated during cooking, play a guiding role for the oil smoke, and thus reduce the probability of oil smoke leakage and escape.

[0066] like Figure 5 and Figure 6 As shown, in some embodiments of the present application, the structure of the air duct housing 100 at the guide channel 120 includes a first side wall 121 and a second side wall 122. The first side wall 121 is opposite to and spaced from the second side wall 122, the guide channel 120 is located between the first side wall 121 and the second side wall 122, and the arc surface is provided on the side of the first side wall 121 facing the second side wall 122. When the airflow flows into the guide channel, the airflow will be guided by the arc surface, deviate from the original flow direction, and flow along the curved direction of the arc surface.

[0067] like Figure 6 As shown, in some embodiments of the present application, the surface of the second side wall 122 facing the first side wall 121 is an arc-shaped surface, and the arc-shaped surface of the second side wall 122 is in the same bending direction as the arc-shaped surface of the first side wall 121. In this way, the first side wall 121 and the second side wall 122 cooperate, and the second side wall 122 can accurately adjust the direction of the airflow ejected from the air outlet 130. The first side wall 121 changes the direction of the airflow through the Coanda effect, and can more accurately adjust the ejection speed and direction of the airflow from the air outlet 130. Of course, the shape setting of the second side wall 122 is not limited to this, such as Fig. 9 and Fig.10 As shown, in some other embodiments of the present application, the shape of the second side wall 122 may be L-shaped. In some other embodiments of the present application, the shape of the second side wall 122 may also be J-shaped.

[0068] like Figure 7As shown, in some embodiments of the present application, the airflow enters the guide channel 120 along the first direction. It should be noted that the direction perpendicular to the first direction is the second direction. In the first direction, the second side wall 122 has a first end 123 and a second end 124, and the second end 124 deviates from the first end 123 in the second direction, and the vertical distance of the second end 124 deviating in the second direction is L1.

[0069] like Figure 7 and Figure 8 As shown, Figure 7 The length of L1 is less than Figure 8 The length of L1, wherein the length of L1 will affect the direction of the airflow emitted from the air outlet 130, the smaller L1 is, the more the direction of the airflow emitted from the air outlet 130 is biased downward; the larger L1 is, the more the direction of the airflow emitted from the air outlet 130 is biased upward. In the first direction, the first side wall 121 has a third end 125 and a fourth end 126, the fourth end 126 deviates from the first end 123 in the second direction, and the vertical distance of the fourth end 126 deviation in the second direction is L2, wherein L2>L1, the specific length setting of L1 needs to be determined according to the angle of the opening and closing plate, the position of the main smoke outlet 31 of the range hood, and the relative position of the air outlet 130 and the main smoke outlet 31, so as to ensure that the airflow emitted from the air outlet 130 can flow in the direction of the main smoke outlet 31 of the range hood, so that the airflow can drive the oil smoke to blow toward the main smoke outlet 31, thereby increasing the probability of the main smoke outlet 31 capturing the oil smoke. Figure 7 As shown, in some embodiments of the present application, L2 is less than or equal to six times L1.

[0070] like Figure 7 As shown, in some embodiments of the present application, the minimum width of the main channel 110 is B1, and the size of B1 will affect the degree of airflow pressurization in the main channel 110. The minimum distance between the second end 124 and the first side wall 121 is B2, wherein the size of B2 will affect the air outlet speed of the air outlet 130. Wherein, B2≤B1, in some embodiments of the present application, the value range of B1 is 2mm-5mm, and the value of B2 can be equal to B1, or slightly less than B1. For example, in this embodiment, B1 can be 3 mm, and B2 can be 2.8 mm.

[0071] like Figure 8 and Fig.12 As shown, in some embodiments of the present application, the guide channel 120 may be in an arc shape. Of course, the shape of the guide channel 120 is not limited thereto. Fig.10 In some other embodiments, the guide channel 120 may be L-shaped. Alternatively, in some other embodiments, the guide channel 120 may be J-shaped.

[0072] like Fig.10 and Fig.12 As shown, in some embodiments of the present application, the guide channel 120 can be a closed channel at the air outlet 130. In this case, the first side wall 121 and the second side wall 122 are arranged opposite to each other, and the length of the second side wall 122 is greater than the length of the first side wall 121. It should be noted that, here, the length of the second side wall 122 refers to the arc length of the second side wall 122, and the length of the first side wall 121 refers to the arc length of the first side wall 121. Or, as Figure 8 and Fig. 9 As shown, in some other embodiments of the present application, the guide channel 120 is an open channel at the air outlet 130 , and the first side wall 121 and the second side wall 122 are staggered, and the length of the first side wall 121 is greater than the length of the second side wall 121 .

[0073] like Fig.11 and Fig.12 As shown, Fig.11 The effect of the open channel on the emission of oil smoke. Fig.12 The closed flow channel has an effect of ejecting oil smoke. Both the open flow channel and the closed flow channel can change the direction of the ejected airflow as needed. However, the air outlet 130 of the open flow channel is located at a position further forward than the guide flow channel 120, and the ejection range is larger. The airflow ejected from the air outlet 130 of the open flow channel will also have an ejection effect on the oil smoke near the opening and closing plate, which can prevent some of the oil smoke from leaking from near the opening and closing plate, and has a better effect of guiding the oil smoke. The air outlet 130 of the closed flow channel is located at a position further back than the guide flow channel 120, and the ejection range is smaller. Therefore, in this embodiment, the open flow channel is preferably used.

[0074] like Figure 6 As shown, in some embodiments of the present application, the guide channel 120 has a constricted section 127 at the air outlet 130, and the cross-sectional area of ​​the constricted section 127 gradually decreases in the direction of air flow. In this way, the wind pressure at the air outlet 130 can be increased, thereby increasing the speed of the airflow ejected from the air outlet 130.

[0075] like Figure 4 and Figure 5 As shown, in some embodiments of the present application, the main flow channel 110 includes a first flow channel section 111 and a second flow channel section 112 that are sequentially connected, and the second flow channel section 112 is connected and communicated with the guide flow channel 120. Specifically, as Figure 5As shown, the second flow channel 112 section is a straight section, so that the second flow channel 112 section can guide and distribute the airflow in the main channel 110. In some embodiments of the present application, the first flow channel 111 section can be trumpet-shaped, and the contraction portion of the first flow channel 111 section is connected and communicated with the second flow channel 112 section. In this way, since the cross-sectional area of ​​the second flow channel 112 section is smaller than the cross-sectional area of ​​the first flow channel 111 section, the second flow channel 112 section will limit the flow space of the airflow, and at the same time make the pressure distribution of the airflow more uniform, so that the airflow velocity can be evenly distributed in the left and right directions of the air outlet 130, thereby reducing the disturbance and resistance of the airflow, reducing the degree of deviation and concentration of the airflow, and thus improving the reliability and stability of the air duct assembly 10.

[0076] like Figure 7 As shown, in some embodiments of the present application, the length L3 of the second flow channel 112 is greater than or equal to 5 times B1. In this way, the flow state of the airflow passing through the contraction portion of the first flow channel 111 in the second flow channel 112 can be made more stable, so that the airflow can flow evenly to the air outlet 130, further improving the reliability and stability of the outlet airflow.

[0077] like Figure 4 and Fig.13 As shown, in some embodiments of the present application, the air duct assembly 10 further includes a fan 201 and a fan housing 200, the fan 113 is used to drive the airflow to flow to the main channel 110, the fan housing 200 is covered by the fan 113, and the fan housing 200 is connected and communicated with the air duct housing 100. Specifically, as Figure 4 As shown, the fan 201 is connected to the end of the first flow channel 111 with a larger cross-sectional area. In this way, by shrinking the cross-sectional area of ​​the first flow channel 111 from the fan 201 to the second flow channel 112, the wind resistance in the first flow channel 111 is increased, so that the fan 201 can operate in the high static pressure range, increase the air supply distance of the fan 201, and then make the pressure of the airflow in the main flow channel 110 evenly distributed along the left and right width directions of the main flow channel 110, and at the same time, under the action of high pressure, the airflow at the air outlet 130 can maintain a certain flow rate, ensuring that the airflow at the air outlet 130 can produce an induced effect.

[0078] like Fig.13 As shown, in some embodiments of the present application, in order to save production costs, the fan housing 200 and the air duct housing 100 can be connected in one piece. Of course, the connection method between the fan housing 200 and the air duct housing 100 is not limited to this. In other embodiments of the present application, in order to facilitate disassembly and assembly, the fan housing 200 and the air duct housing 100 can also be connected in a splicing manner.

[0079] like Figure 7As shown, in some embodiments of the present application, the total thickness of the air duct housing 100 is L4, and the size of L4 is determined by the size of the fan 201. In order to reduce the overall thickness of the air duct assembly 10 and ensure the slim appearance of the opening and closing plate, the size of L4 can be less than or equal to 30 mm.

[0080] As shown in the figure, the maximum left and right width of the air duct housing 100 is H. For an air curtain device composed of two left and right air ducts, H can be less than or equal to 400 mm, and the air ducts should be arranged evenly or symmetrically along the left and right width directions of the fan. Figure 2 and Figure 3 As shown, the range hood provided by the present application includes a case 30, an opening and closing plate 20 and the above-mentioned air duct assembly 10. The case 30 is provided with a smoke outlet 31, the opening and closing plate 20 is flippably arranged on the case 30, the opening and closing plate 20 is suitable for covering or opening the smoke outlet 31, and the opening and closing plate 20 is provided with an air inlet 21; the air duct assembly 10 is arranged on the side of the opening and closing plate 20 facing the smoke outlet 31, and the air inlet end of the air duct assembly 10 is opposite to the air inlet 21. When multiple air duct assemblies 10 are arranged on the opening and closing plate, the total width of the air duct housing 100 can be less than or equal to 900 mm.

[0081] Combine the following Figures 2 to 13 To illustrate the working process of the air duct assembly 10 and the range hood provided by the present application. When the range hood is working, the fan 201 in the air duct assembly 10 rotates, and the external air enters the main channel 110 from the air inlet 21 on the opening and closing plate, and the fan 201 disturbs the air to make it become an airflow flowing in the main channel 110. When the airflow passes through the contraction of the first channel 111 section, the wind pressure increases, and the flow rate of the airflow increases. The airflow will stabilize its own flow state during the flow of the second channel 112 section, so that the pressure in the second channel 112 section is evenly distributed. When the airflow reaches the guide channel 120, the airflow will flow in the direction of the arc section of the first side wall 121, and form a Coanda effect at the air outlet 130, so that the direction of the airflow can flow toward the smoke outlet 31 of the range hood, and the oil smoke is carried and mixed together through the induced effect and blown to the smoke outlet 31 of the range hood for discharge, thereby reducing the probability of oil smoke leakage and escape.

[0082] Finally, it should be noted that the above implementation modes are only used to illustrate the present application, and are not intended to limit the present application. Although the present application is described in detail with reference to the embodiments, a person skilled in the art should understand that various combinations, modifications or equivalent substitutions of the technical solutions of the present application do not depart from the spirit and scope of the technical solutions of the present application, and should be included in the scope of the claims of the present application.

Claims

1. An air duct assembly, characterized in that: include: An air duct shell has a main flow channel and a guide flow channel, one end of the guide flow channel is connected to the main flow channel, the other end of the guide flow channel is an air outlet, the inner wall of the guide flow channel is a curved surface, and the curved surface is used to guide the airflow so that the airflow forms a Coanda effect at the air outlet.

2. The air duct assembly according to claim 1, characterized in that: The structure of the air duct housing at the guide flow channel includes a first side wall and a second side wall, the first side wall is opposite to and spaced from the second side wall, and the guide flow channel is located between the first side wall and the second side wall; The arc surface is arranged on a side of the first side wall facing the second side wall.

3. The air duct assembly according to claim 2, characterized in that: The surface of the second side wall facing the first side wall is an arc-shaped surface; Alternatively, the second side wall is L-shaped or J-shaped.

4. The air duct assembly according to claim 2, characterized in that: The airflow enters the guide channel along a first direction, and a direction perpendicular to the first direction is a second direction. In the first direction, the second side wall has a first end and a second end, the second end deviates from the first end in the second direction, and the vertical distance of the second end deviation in the second direction is L1; In the first direction, the first side wall has a third end and a fourth end, the fourth end deviates from the first end in the second direction, and the vertical distance of the deviation of the fourth end in the second direction is L2, wherein L2>L1.

5. The air duct assembly according to claim 4, characterized in that: The L2 is less than or equal to six times of L1.

6. The air duct assembly according to claim 4, characterized in that: In the direction from the first side wall to the second side wall, the minimum width of the main channel is B1, A minimum distance between the second end and the first side wall is B2, where B2≤B1.

7. The air duct assembly according to claim 6, characterized in that: The value range of B1 is 2mm-5mm.

8. The air duct assembly according to claim 1, characterized in that: The guide flow channel is in an arc shape, an L shape, or a J shape.

9. The air duct assembly according to claim 1, characterized in that: The guide flow channel is a closed flow channel or an open flow channel at the air outlet.

10. The air duct assembly according to claim 1, characterized in that: The guide flow channel has a constricted section at the air outlet, and the cross-sectional area of ​​the constricted section gradually decreases in the direction of airflow flow.

11. The air duct assembly according to claim 1, characterized in that: The main flow channel includes a first flow channel section and a second flow channel section that are connected in sequence, the second flow channel section is connected to and communicates with the guide flow channel, and the second flow channel section is a straight section.

12. The air duct assembly according to claim 11, characterized in that: The first flow channel section is trumpet-shaped.

13. The air duct assembly according to any one of claims 1 to 12, characterized in that: Also includes: A fan, the fan is used to drive airflow to flow toward the main channel; A fan housing is provided, wherein the fan housing covers the fan and is connected and communicated with an air duct housing.

14. The air duct assembly according to claim 13, characterized in that: The fan housing and the air duct housing are integrally formed; Alternatively, the fan housing is spliced ​​and connected to the air duct housing.

15. A range hood, characterized in that: include: A chassis, wherein the chassis is provided with a smoking port; An opening and closing plate, the opening and closing plate is flippably arranged on the chassis, the opening and closing plate is suitable for covering or opening the smoking port, and the opening and closing plate is provided with an air inlet; The air duct assembly is the air duct assembly according to any one of claims 1 to 14, the air duct assembly is arranged on the side of the opening and closing plate facing the smoking port, and the air inlet end of the air duct assembly is aligned with the air inlet.

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