An air inlet channel of a range hood and a range hood

Abstract

The utility model discloses an air inlet channel and range hood of range hood, the air inlet channel of this range hood includes box and the air duct in the box, and the air duct has the first port of being the noise sound wave entrance and the second port of being the airflow entrance, and the length direction of air duct is recorded as Z axle direction, and the first port and the second port are arranged along the Z axle direction interval, and the width direction of air duct is recorded as X axle direction, the wall surface of constituting the air duct at least includes: the sound -facing surface is to the sound wave input direction and is with the sound wave impact, and the sound -facing surface is the wall surface that can supply the noise to pass, and the sound -facing surface at least includes with the first sound -facing surface of first port edge link, and the flow -facing surface is to the airflow input direction and is with the airflow impact, and the flow -facing surface is at least partly the wall surface of closed, and the box is formed with the wall surface between constituting the air duct and the noise reduction chamber, and in the noise reduction chamber, at least in the first sound -facing surface and in the X axle direction adjacent box wall surface between the first sound -absorbing material or structure is arranged.

Description

Technical Field

[0001] This utility model relates to an oil fume purification device, and more particularly to an air inlet channel for a range hood, and a range hood using the air inlet channel. Background Technology

[0002] As living standards continue to improve, consumers' demands for home appliances have shifted from simple functional needs to diversified quality requirements. Taking range hoods as an example, while ensuring efficient smoke extraction, they also need to operate with low noise. Quiet performance has become one of the core indicators for consumers to evaluate the quality of home appliances, directly affecting the product's market competitiveness and user experience.

[0003] Existing range hoods with noise reduction functions typically target fluid noise. For example, a range hood disclosed in Chinese Patent Application No. 202010220272.8 includes a flue and a fan. The flue is non-linear, and the air inlet of the fan is connected to one end of the flue. This allows the noise generated by the airflow from the fan to be reflected more before leaving the flue and being perceived by the user. The flue uses a core plate to guide the oil fumes along an arc shape, keeping the flow within the flue smooth.

[0004] However, among the noise sources of range hoods, the noise generated by the fan is one of the most significant and prevalent. As a core functional module, the performance of the fan directly affects the smoke extraction effect, so noise reduction cannot be achieved simply by reducing the fan power. Furthermore, since fan noise mainly propagates outward through the air duct, it is also impossible to reduce fan noise by isolating or closing the air duct.

[0005] Therefore, the applicant's application number 202222311210.5 proposes a fan system for a range hood, including an internally hollow air box, a centrifugal fan installed inside the air box, an air inlet and an air outlet on the air box, the outlet of the centrifugal fan being connected to the air outlet, a flow guide and noise reduction frame connected to the air inlet of the air box, a flow guide and noise reduction cavity formed within the flow guide and noise reduction frame, and a flow guide plate installed within the flow guide and noise reduction cavity. By connecting the flow guide and noise reduction frame to the air inlet of the air box, the uneven airflow velocity caused by the cross-sectional change in the air duct can be adjusted. The sound-absorbing cotton installed on the inner sidewall of the flow guide and noise reduction cavity can increase the absorption of noise transmitted downward from the air box, reduce the mechanical vibration noise (such as centrifugal fan, impeller) at the upper end, and reduce some of the aerodynamic noise transmitted downward.

[0006] The aforementioned range hoods achieve noise reduction by setting up a flow-guiding noise reduction frame, optimizing the duct curve design, and combining sound-absorbing materials. However, the walls of these ducts are made of sound-absorbing cotton or have a porous sound-absorbing cavity structure. This means that during the noise propagation process, after passing through the duct and entering the sound-absorbing structure outside the duct, the noise is reflected through the duct wall and re-enters the duct, and then exits from the duct port, thus failing to achieve the ideal noise reduction effect. Utility Model Content

[0007] The first technical problem to be solved by this utility model is to address the shortcomings of the existing technology by providing an air intake channel for a range hood that can improve noise reduction.

[0008] The second technical problem to be solved by this utility model is to provide a range hood with the above-mentioned air intake channel.

[0009] The technical solution adopted by this utility model to solve the first technical problem mentioned above is as follows: an air inlet channel for a range hood, used to be disposed between the smoke inlet of the range hood and the fan; the air inlet channel includes a housing and an air duct located inside the housing, the air duct having a first port as a noise sound wave inlet and a second port as an airflow inlet, the length direction of the air duct is denoted as the Z-axis direction, the first port and the second port are arranged at intervals along the Z-axis direction, the width direction of the air duct is denoted as the X-axis direction, and the X-axis direction and the Z-axis direction are perpendicular to each other; characterized in that:

[0010] The walls constituting the air duct include at least:

[0011] A frontal surface, facing the direction of sound wave input and impacting the sound wave, wherein the frontal surface is a wall surface that allows noise to pass through, and the frontal surface at least includes a first frontal surface connected to the edge of the first port; and

[0012] A frontal surface, which faces the direction of airflow input and impacts the airflow, wherein the frontal surface is at least partially a closed wall;

[0013] A noise reduction cavity is formed between the enclosure and the wall that forms the air duct. In the noise reduction cavity, a first sound-absorbing material or structure is provided at least between the first frontal surface and the adjacent enclosure wall in the X-axis direction.

[0014] Utilizing the characteristic that airflow and sound waves propagate in opposite directions, the duct wall of the range hood's air intake channel is divided into two different functional surfaces: a sound-facing surface and a flow-facing surface. This approach balances both noise reduction and flow field performance, improving both noise reduction and flow field efficiency. The noise reduction cavity located on the side of the sound-facing surface facing outwards from the duct contains a first sound-absorbing material or structure that absorbs noise waves entering from the sound-absorbing surface, preventing them from re-entering the duct. Furthermore, the closed wall design of the flow-facing surface increases the number of times noise is absorbed, significantly enhancing the noise reduction effect.

[0015] Furthermore, along the X-axis, there is a gap between the first sound-absorbing material or structure and the adjacent wall of the enclosure, and along the X-axis, the maximum width of the first sound-absorbing material or structure is L, and the minimum width of the gap between the first sound-absorbing material or structure and the wall of the enclosure is ΔL. This can save on the materials used for the first sound-absorbing material or structure, saving costs while ensuring sound absorption effect.

[0016] Furthermore, the frontal surface includes at least a first frontal surface connected to the edge of the first port, and the first frontal surface and the first frontal surface are disposed opposite to each other.

[0017] Furthermore, within the noise reduction cavity, a second sound-absorbing material or structure is provided between the first incoming surface and the adjacent box wall in the X-axis direction, thereby absorbing the noise reflected from the first incoming surface.

[0018] Preferably, both the first sound-absorbing material or structure and the second sound-absorbing material or structure are sound-absorbing cotton.

[0019] Furthermore, the air duct is composed of a first plate and a second plate arranged at intervals along the X-axis inside the box, and the space between the two plates constitutes the air duct. The inner surface of each plate constituting the air duct includes at least two curved surfaces or planes connected end to end, or the inner surface of each plate constituting the channel is composed of a curved surface or plane.

[0020] Furthermore, to facilitate the maintenance or replacement of the air duct, sound-absorbing material, or structure, according to one aspect of this utility model, the tops of the first plate and the second plate are detachably connected to the top of the housing, and the first plate and the second plate are also detachably connected to both sides of the housing along the Y-axis direction, where the Y-axis direction is the depth direction of the air duct, and the X-axis, Y-axis, and Z-axis are perpendicular to each other.

[0021] Furthermore, to facilitate the maintenance or replacement of the air duct, sound-absorbing materials, or structure, according to another aspect of this utility model, along the X-axis direction, the adjacent wall surfaces of the housing and the second plate form a front cover plate, the front cover plate being detachable relative to other parts of the housing, the top of the second plate being connected to the top of the housing, and the second plate also being connected to the front cover plate.

[0022] Preferably, the first plate and the second plate are either integral plates or spliced ​​plates.

[0023] The technical solution adopted by this utility model to solve the second technical problem mentioned above is: a range hood, characterized in that: it applies an air inlet channel as described above.

[0024] Compared with the prior art, the advantages of this utility model are as follows: Utilizing the characteristic that airflow and sound waves propagate in opposite directions, the duct wall of the range hood's air intake channel is divided into two different functional surfaces: a sound-facing surface and a flow-facing surface. This can take into account both noise reduction and flow field performance indicators. While improving the noise reduction effect, the flow field efficiency is also better. The noise reduction cavity located on the side of the sound-facing surface facing outwards from the duct is equipped with a first sound-absorbing material or structure, which can absorb noise waves entering from the sound-absorbing surface and prevent them from re-entering the duct. In addition, the closed wall design of the flow-facing surface can increase the number of times noise is absorbed, which can significantly improve the noise reduction effect. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the range hood according to the first embodiment of the present utility model;

[0026] Figure 2 This is a cross-sectional view of the range hood according to the first embodiment of this utility model;

[0027] Figure 3 This is a cross-sectional view of the range hood according to the first embodiment of the present invention (and...). Figure 2 (Different perspectives);

[0028] Figure 4 This is a cross-sectional side view of the silencer duct of the range hood according to the first embodiment of this utility model;

[0029] Figure 5 This is a schematic diagram of one embodiment of the frontal surface of the noise reduction device of this utility model;

[0030] Figure 6 This is a schematic diagram of an alternative embodiment of the frontal surface of the noise reduction device of this utility model;

[0031] Figure 7 This is a schematic diagram of an alternative embodiment of the frontal surface of the noise reduction device of this utility model;

[0032] Figure 8 This is a schematic diagram of an alternative embodiment of the frontal surface of the noise reduction device of this utility model. Detailed Implementation

[0033] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0034] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description. They 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 utility model 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.

[0035] See Figures 1-4 A range hood includes a fan 200, an air inlet 300, and an air inlet channel 100 disposed between the fan 200 and the air inlet 300. When the range hood is turned on, the fan 200 starts and draws in cooking fumes through the smoke inlet (not labeled, existing technology) at the air inlet 300, and then exhausts them through the fan 300.

[0036] In this embodiment, the range hood can be a ceiling-mounted type, meaning its fan 200 is placed above the kitchen ceiling. The fan 200 is horizontally arranged, meaning it has a downward-facing air inlet 201, and there is sufficient space between the air inlet body 300 and the fan 200 to accommodate the air inlet channel 100. Of course, in other types of range hoods, the air inlet channel 100 of appropriate size can be selected according to the actual space.

[0037] The air inlet duct 100 includes a housing 1 and plates disposed within the housing 1. Two plates, a first plate 21 and a first plate 22, are spaced apart from each other. The space between the two plates forms an air duct Q. The first plate 21 can be a single plate or composed of at least two plates joined together; similarly, the second plate 22 can be a single plate or composed of at least two plates joined together. The air duct Q extends between two opposing walls of the housing 1 (each plate contacts its corresponding wall of the housing 1). Thus, the air duct Q has a first port 221 and a second port 211. The first port 221 serves as both a fluid outlet and a noise inlet, while the second port 211 serves as both a fluid inlet and a noise outlet. The housing 1 has openings at positions corresponding to the first port 221 and the second port 211. In this embodiment, the first port 221 is located at the top of the air duct Q, and the second port 211 is located at the bottom of the air duct Q. The direction in which the air duct Q extends between the second port 211 and the first port 221 is the length direction (Z-axis direction) of the air duct Q. The second port 211 and the first port 221 are arranged at intervals along the Z-axis. Here, "interval arrangement" does not strictly require that the second port 211 and the first port 221 be aligned along the X-axis (described in detail below). They can be arranged as follows: Figure 4 The diagram shows an aligned arrangement, but a staggered arrangement is also possible. The direction in which the air duct Q extends between the two plates is the width direction of the air duct Q. Figure 4 The X-axis direction is shown in the diagram. Each plate is positioned along the depth of the air duct Q. Figure 4 The direction perpendicular to the paper plane (i.e., the Y-axis direction) shown in the diagram all extends to contact the outer casing 1 to form a relatively enclosed air duct Q.

[0038] Due to the ultra-thin shape limitation of the air inlet 300 in this embodiment, the air duct Q is designed to fit it, forming a long and narrow shape along the left-right direction of the range hood. The two plates are spaced apart along the front-back direction of the range hood, meaning the width direction of the air duct Q is the front-back direction of the range hood. Each plate extends to contact the housing 1 in the depth direction of the air duct Q (i.e., the left-right direction of the range hood in this embodiment) to form a relatively enclosed air duct Q. The airflow enters the second port 211 in the same direction as the length direction of the air duct Q (perpendicular or nearly perpendicular to the second port 211), and the noise wave enters the first port 221 in the same direction as the length direction of the air duct Q (perpendicular or nearly perpendicular to the first port 221).

[0039] Each plate forming the inner surface of the air duct Q includes one or at least two curved surfaces or planes connected end to end. In the cross-section of the plane along the length and width directions of the air duct Q, in this embodiment, it is the vertical plane S (the plane containing the X-axis and Z-axis) extending along the front-back direction of the range hood. Figures 2-4 The cross section and Figure 1The vertical planes S shown in the diagram coincide or are parallel, with wavy or sawtooth inner surfaces. The curvature of adjacent surfaces can be the same or different. The number of surfaces or planes can also be selected as needed. This forms a non-linear air duct, which helps reduce noise.

[0040] In the air ducts of household appliances, the fluid (usually airflow) and sound waves propagate in opposite directions. When a range hood is working, cooking fumes are drawn upwards, while the noise from the fan 200 propagates downwards. Therefore, based on this characteristic of airflow and sound wave propagation in opposite directions, this invention divides the inner surfaces of each panel into two different functional areas: the sound-facing surface and the airflow-facing surface. The sound-facing surface is the main surface on which sound waves directly incident, aligned with the direction of sound wave propagation. It allows noise waves to pass through, and the airflow does not directly impact this area during its propagation. The airflow-facing surface, on the other hand, is the main surface on which the airflow directly impacts, aligned with the direction of airflow propagation. The airflow-facing surfaces on opposite sides along the X-axis have at least one sound-facing surface and at least one airflow-facing surface, with the sound-facing surface on one side facing the airflow-facing surface on the other.

[0041] In this embodiment, each consists of two planes connected end-to-end. The planes can transition using curved surfaces or directly. The transition points between adjacent planes on each plate protrude in the same direction, such as... Figure 2 As shown, it protrudes forward. Therefore, the first plate 21 located on the rear side has its upper and lower ends positioned behind the intermediate transition position, with this intermediate transition position forming a first boundary 212. The inner surface of the first plate 21 above this first boundary 212 facing the air duct Q is the first acoustic surface 231, and the inner surface of the first plate 21 below this first boundary 212 facing the air duct Q is the second airflow surface 242. The second plate 22 located on the front side has its upper and lower ends positioned behind the intermediate transition position, with this intermediate transition position forming a second boundary 222. The inner surface of the second plate 22 above this second boundary 222 facing the air duct Q is the first airflow surface 241, and the inner surface of the second plate 22 below this second boundary 222 facing the air duct Q is the second acoustic surface 232. The first boundary 212 refers to the portion of the side plate that does not extend beyond it and is further away from the rear wall of the housing 1, and the second boundary 222 refers to the portion of the side plate that does not extend beyond it and is closer to the front wall of the housing 1. The first frontal surface 231 and the second frontal surface 241 are arranged opposite to each other.

[0042] As mentioned above, the first plate 21 and the second plate 22 each involve multiple plates spliced ​​together. Therefore, there is a possibility of incomplete and discontinuous transitions between adjacent acoustic and airflow-facing surfaces, or discontinuous extensions within the same surface. The "end-to-end connection" described above does not necessarily mean a smooth transition; misalignment is permissible at the connection point. See also... Figure 4In this embodiment, for reasons such as installation, transportation, and manufacturing, the second airflow-facing surface 242 and the second acoustic-facing surface 232 are respectively formed by splicing two surfaces arranged vertically. Thus, the second airflow-facing surface 242 is divided into a first part 2421 and a second part 2422, and the second acoustic-facing surface 232 is divided into a third part 2321 and a fourth part 2322.

[0043] Each airflow-facing surface is at least partially enclosed. The enclosed surface can be smooth or rough and can reflect noise waves. When the airflow enters upward from the second port 211 (approximately perpendicular to the second port 211), because the second airflow-facing surface 242 on the lower left side of the figure bulges to the right relative to the second port 211, at least part of the airflow will collide with the first airflow-facing surface 242, guiding it and flowing out from the first port 221 after passing through multiple airflow-facing surfaces in sequence.

[0044] The frontal surface is at least partially enclosed. In this invention, "partially enclosed wall" refers to, see [link to relevant documentation]. Figure 5 In one embodiment of the partially enclosed frontal surface, a first boundary line S1 is taken along the Z-axis direction, intersecting with both sides of the frontal surface in the Y-axis direction, thereby dividing the frontal surface into two regions along the Z-axis direction, namely the first region S11 and the second region S12. As shown in the figure, the second region S12 is a fully enclosed wall (i.e., without any openings). Alternatively, the first region S11 can also be a fully enclosed wall.

[0045] See Figure 6 In an alternative embodiment where the frontal surface is partially closed, both the first region S11 and the second region S12 have openings. The opening ratio of the second region S12 shown in the figure is ≤20%. These openings in the second region S12 may be for installation or other requirements. The circular holes in the figure represent holes, but it is understood that the shape of the holes is not limited. Alternatively, the first region S11 can be a wall surface with an opening ratio of ≤20%.

[0046] The above Figure 5 , Figure 6 The closed wall shown is located adjacent to the boundary along the Y-axis. Alternatively, see [link to alternative]. Figure 7 An alternative embodiment of partially enclosed frontal surface involves taking two second boundary lines S2 along the Y-axis, arranged parallel to each other along the Z-axis. Each second boundary line S2 intersects both sides of the frontal surface along the Y-axis, thereby dividing the frontal surface along the Z-axis into a third region S21, a fourth region S22, and a fifth region S23. The fourth region S22, located between the two second boundary lines S2, is a fully enclosed wall. Alternatively, see [link to alternative embodiment]. Figure 8 The opening ratio of the fourth region S22 is ≤20%, and the openings in the fourth region S22 may be for installation or other needs.

[0047] The plate area corresponding to each frontal sound surface is composed of perforated plates, sound-absorbing materials, or other materials or structures that allow noise to easily pass through. At least one end of the plate area corresponding to each frontal sound surface extends along the Z-axis to the corresponding wall surface of the housing 1. Thus, the plate area corresponding to the frontal sound surface, the plate area corresponding to the adjacent frontal sound surface, and the corresponding wall surface of the housing 1 together constitute the noise reduction cavity Q1. Figure 4 Taking the noise reduction cavity Q1 on the left as an example, the adjacent first frontal surface 231, the second frontal surface 242 and their corresponding plate areas, as well as the upper and left side walls of the housing 1, together constitute this noise reduction cavity Q1 (acoustic trap).

[0048] Except for the plate area corresponding to the frontal surface, all other walls constituting the noise reduction cavity Q1 are at least partially closed walls. The first frontal surface 231 of the first plate 21 and the adjacent walls of the enclosure 1 ( Figure 4 A first sound-absorbing material or structure 251 is provided in the noise reduction cavity Q1 between the left wall shown in the figure. The first sound-absorbing material or structure 251 can absorb the noise entering the corresponding noise reduction cavity Q1. The first airflow-facing surface 241 of the second plate 22 and the adjacent wall of the box 1 (shown in the figure) Figure 4 A second sound-absorbing material or structure 252 is provided in the noise reduction cavity Q1 between the right side wall shown in the diagram, which can absorb noise reflected by the first sound-facing surface 231. The first sound-absorbing material or structure 251 and the second sound-absorbing material or structure 252 are preferably sound-absorbing cotton.

[0049] Thus, noise enters the air duct Q downwards from the first port 221 (approximately perpendicular to the first port 221). Since the first acoustic surface 231 bulges to the right relative to the first port 221, some noise passes through the plate area corresponding to the first acoustic surface 231 and enters the corresponding noise reduction cavity Q1. Inside, it undergoes multiple reflections and interferences until the sound wave energy is completely dissipated or only a small portion escapes and re-enters the air duct Q. Other noise is reflected to the first airflow surface 241 opposite to the first acoustic surface 231, and then reflects multiple times between the opposing acoustic and airflow surfaces, dissipating its energy. Only a small portion of the noise escapes from the second port 211. Because the airflow surface is partially enclosed, it also prevents sound waves within the noise reduction cavity Q1 from escaping through its enclosed portion.

[0050] As described above, in this embodiment, the first acoustic surface 231 connected to the first port 221 is located on the first plate 21, and the connection point between the second plate 22 and the first port 221 is the first airflow surface 241. Therefore, more sound waves enter the noise reduction cavity Q1 between the first plate 21 and the adjacent walls of the housing 1, while relatively fewer sound waves enter the noise reduction cavity Q1 between the second plate 22 and the adjacent walls of the housing 1. Therefore, sound-absorbing material or structures can also be provided between the first airflow surface 241 and the adjacent walls of the housing 1, while other locations between the second plate 22 and the adjacent walls of the housing 1 do not need to be provided with sound-absorbing material or structures.

[0051] Within the noise reduction cavity Q1 between the first plate 21 and the adjacent walls of the housing 1, a gap 253 exists between the first sound-absorbing material or structure 251 and the adjacent wall of the housing 1 along the X-axis direction. Along the X-axis direction, the maximum width of the first sound-absorbing material or structure 251 within the noise reduction cavity Q1 is L, and the minimum width of the gap (253) between the first sound-absorbing material or structure 251 and the wall of the housing 1 is ΔL. This saves on the amount of sound-absorbing material or structure 25, reducing costs, while ensuring that the noise reduction effect is equivalent to that of full filling.

[0052] For ease of disassembly and maintenance, or replacement of sound-absorbing materials or structure 25, the first plate 21 and the second plate 22 are detachably connected to the enclosure 1. The first plate 21 and the second plate 22 are both sheet metal parts, and can be connected to both sides of the enclosure 1 along the Y-axis direction by screws. In addition, the top of the first plate 21 is connected to the top of the enclosure 1, such as at the edge of the first port 221, and the top of the second plate 22 is connected to the top of the enclosure 1, such as at the edge of the second port 221.

[0053] Alternatively, along the X-axis, the adjacent walls of the housing 1 and the second plate 22 form a front cover 11, which can be detached relative to other parts of the housing 1. The top of the second plate 22 is connected to the top of the housing 1, and the second plate 22 is also connected to the front cover 11. Thus, during disassembly, the front cover 11, the front sound-absorbing material or structure 25, and the second plate 22 can be removed together, avoiding multi-layer disassembly and improving disassembly efficiency.

[0054] When each plate is connected to the housing 1, a connecting surface can be provided by forming a flange, such as a connection position for screws to pass through.

[0055] The speed of the aforementioned fan 200 can be intelligently voice-controlled. Therefore, the range hood can be equipped with an intelligent voice control module, which includes a controller, a voice receiving module, and a voice parsing module. The voice receiving module can receive user commands, and the voice parsing module can analyze these commands. Based on the analyzed commands, the module controls the range hood to perform corresponding operations, thereby achieving intelligent control of the range hood and improving the user experience. Of course, the dimensions of the aforementioned duct Q and the dimensions of the sound-absorbing materials or structures still need to meet the operating conditions under intelligent control.

Claims

1. An air inlet channel for a range hood, used to be disposed between the smoke inlet of the range hood and a fan (200); the air inlet channel includes a housing (1) and an air duct (Q) located within the housing (1), the air duct (Q) having a first port (221) as a noise sound wave inlet and a second port (211) as an airflow inlet, the length direction of the air duct (Q) is denoted as the Z-axis direction, the first port (221) and the second port (211) are arranged at intervals along the Z-axis direction, the width direction of the air duct (Q) is denoted as the X-axis direction, and the X-axis direction and the Z-axis direction are perpendicular to each other; characterized in that: The wall surface constituting the air duct (Q) includes at least: A frontal surface, facing the direction of sound wave input and impacting the sound wave, the frontal surface being a wall surface that allows noise to pass through, the frontal surface including at least a first frontal surface (231) connected to the edge of the first port (221); and A frontal surface, which faces the direction of airflow input and impacts the airflow, wherein the frontal surface is at least partially a closed wall; A noise reduction cavity (Q1) is formed between the housing (1) and the wall forming the air duct (Q). In the noise reduction cavity (Q1), a first sound-absorbing material or structure (251) is provided at least between the first frontal surface (231) and the adjacent housing (1) wall in the X-axis direction.

2. The air inlet channel of the range hood according to claim 1, characterized in that: In the X-axis direction, the first sound-absorbing material or structure (251) is provided with a gap (253) from the adjacent wall surface of the cabinet (1), and in the X-axis direction, the maximum width of the first sound-absorbing material or structure (251) is L, the minimum width of the gap (253) between the first sound-absorbing material or structure (251) and the wall surface of the cabinet (1) is ΔL, and the following condition is satisfied 3. The air inlet channel of the range hood according to claim 1 or 2, characterized in that: The frontal surface includes at least a first frontal surface (241) connected to the edge of the first port (221), and the first frontal surface (231) and the first frontal surface (241) are arranged opposite to each other.

4. The air inlet channel of the range hood according to claim 3, characterized in that: Inside the noise reduction cavity (Q1), a second sound-absorbing material or structure (252) is provided between the first airflow-facing surface (241) and the adjacent wall of the box (1) in the X-axis direction.

5. The air inlet channel of the range hood according to claim 4, characterized in that: The first sound-absorbing material or structure (251) and the second sound-absorbing material or structure (252) are both sound-absorbing cotton.

6. The air inlet channel of the range hood according to claim 1 or 2, characterized in that: The air duct (Q) is composed of a first plate (21) and a second plate (22) arranged at intervals along the X-axis direction inside the housing (1). The space between the two plates constitutes the air duct (Q). The inner surface of each plate constituting the air duct (Q) includes at least two curved surfaces or planes connected end to end, or the inner surface of each plate constituting the channel is composed of a curved surface or plane.

7. The air inlet channel of the range hood according to claim 6, characterized in that: The tops of the first plate (21) and the second plate (22) are detachably connected to the top of the housing (1). The first plate (21) and the second plate (22) are also detachably connected to both sides of the housing (1) along the Y-axis direction. The Y-axis direction is the depth direction of the air duct (Q). The X-axis, Y-axis and Z-axis are perpendicular to each other.

8. The air inlet channel of the range hood according to claim 6, characterized in that: Along the X-axis, the adjacent walls of the housing (1) and the second plate (22) form a front cover (11), which is detachable relative to other parts of the housing (1). The top of the second plate (22) is connected to the top of the housing (1), and the second plate (22) is also connected to the front cover (11).

9. The air inlet channel of the range hood according to claim 6, characterized in that: The first plate (21) and the second plate (22) are either integral plates or spliced ​​plates, respectively.

10. A range hood, characterized in that: The range hood has an air inlet duct as described in any one of claims 1 to 9.

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