Noise reduction device and range hood

Abstract

The utility model relates to the technical field of range hoods, and discloses a noise reduction device and a range hood, the noise reduction device is arranged in a noise reduction cavity of the range hood, the noise reduction cavity is installed on a coaming of a volute of the range hood, the coaming is provided with micro-perforated holes, and the micro-perforated holes are communicated with the noise reduction cavity. The noise reduction device is provided with at least one step face, a step cavity is formed between the step face and the inner wall of the noise reduction cavity, and the width of the step cavity is enlarged in the flowing direction of sound waves in the noise reduction cavity. A noise reduction device with at least one step surface is arranged in a noise reduction cavity, so that a step cavity is formed between the step surface and the inner wall of the noise reduction cavity, the step cavity has different widths in the flowing direction of sound waves in the noise reduction cavity, and in the flowing process of the sound waves in the step cavity, the sound waves pass through a variable cross-section area due to the change of the cross section of the step cavity; therefore, the noise frequency band characteristic of the range hood can be adapted, the problem that the noise reduction frequency band of the noise reduction cavity is single is solved, and the noise reduction effect of the range hood is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to range hood technical field especially, relates to a kind of noise reduction device and range hood. BACKGROUND

[0002] Due to fan under, noise transmission path is short, and the role of noise reduction module is small. The noise reduction cavity of coaming can effectively reduce the noise generated at the noise source volute, but the noise reduction cavity can only absorb and reduce noise of a certain frequency band at present, and the noise frequency band in the fan is wide, cannot maximize the role of noise reduction cavity, leading to poor noise reduction.

[0003] Therefore, a noise reduction device and range hood are needed to solve the above problems. SUMMARY

[0004] One purpose of the utility model is to provide a kind of noise reduction device, can solve the problem that the noise reduction frequency band of range hood volute coaming noise reduction cavity is single, improve the noise reduction effect of range hood.

[0005] As conceived above, the technical scheme adopted by the utility model is:

[0006] A kind of noise reduction device is provided, and the noise reduction device is arranged in the noise reduction cavity of range hood, and the noise reduction cavity is installed on the coaming of the volute of range hood, micro-perforation is arranged on the coaming, and the micro-perforation is communicated with the noise reduction cavity;

[0007] The noise reduction device has at least one step surface, and the step cavity is formed between the step surface and the inner wall of the noise reduction cavity, and the width of the step cavity is enlarged along the sound wave flow direction in the noise reduction cavity.

[0008] Optionally, along the sound wave flow direction in the noise reduction cavity, the step cavity includes a plurality of cavities communicated in sequence, the depth of a single cavity is H1, and 40mm≤H1≤50mm.

[0009] Optionally, the noise reduction device has two, and the two noise reduction devices are oppositely arranged, and the interval between the two noise reduction devices forms a step cavity, and the opposite faces of the two noise reduction devices are step surfaces.

[0010] Optionally, the noise reduction device includes a step plate and a partition plate assembly, the partition plate assembly includes a frame, the frame includes a first side plate and a second side plate arranged at an angle, the first side plate abuts the inner side wall of the noise reduction cavity, and the step plate is connected between the first side plate and the second side plate.

[0011] Optionally, the noise reduction device has an inner cavity, a slit is arranged on the step surface, the slit is communicated with the inner cavity, a first partition plate is arranged in the inner cavity, the first partition plate has a spacing with the inner wall of the noise reduction cavity, and the projection of the first partition plate along the slit depth direction covers the slit.

[0012] Optionally, the first partition plate is provided in plurality, and the plurality of first partition plates are arranged along the depth direction of the slit.

[0013] Another object of the utility model is to provide a range hood, can solve the problem that the range hood volute coaming noise reduction cavity noise frequency band is single, improve the noise reduction effect of range hood.

[0014] As conceived above, the utility model adopts the technical scheme of:

[0015] Provide a kind of range hood, including noise reduction cavity, volute and above-mentioned noise reduction device, noise reduction cavity is installed on the coaming of volute, micro-perforation is provided on coaming, micro-perforation is communicated with noise reduction cavity, and noise reduction device is set in noise reduction cavity.

[0016] Optionally, the inner bottom wall of the noise reduction cavity is provided with a limiting protrusion, a limiting groove is formed between the limiting protrusion and the inner side wall of the noise reduction cavity, and the noise reduction device is inserted into the limiting groove and abuts against the inner side wall of the noise reduction cavity.

[0017] Optionally, the range hood further includes a fixing assembly, the outer side wall of the noise reduction cavity is provided with a mounting slot penetrating through both ends, the fixing assembly includes a first connecting piece and a second connecting piece detachably connected by a fastener, the first connecting piece and the second connecting piece are both slidingly inserted into the mounting slot, and the end of the first connecting piece and the second connecting piece not connected to each other can abut against the volute.

[0018] Optionally, the noise reduction cavity includes a cavity part and two arc-shaped side walls connected, the arc-shaped side walls extend along the circumference of the volute and abut against the coaming, the mounting slot is provided on the arc-shaped side wall, and the fixing assembly is provided in at least one group, and the at least one group of fixing assemblies are arranged in the mounting slot of one arc-shaped side wall.

[0019] The utility model has the advantages of:

[0020] The noise reduction device provided by the utility model is arranged in the noise reduction cavity of the range hood, the noise reduction cavity is installed on the coaming of the volute of the range hood, micro-perforation is provided on the coaming, the micro-perforation is communicated with the noise reduction cavity, when airflow flows in the volute, it can flow into the noise reduction cavity through the noise reduction hole, when the frequency of the inflowing sound wave approaches the natural frequency of the noise reduction hole, the air column in the noise reduction hole will vibrate strongly, the air vibrates and rubs on the inner wall of the noise reduction hole, due to the effect of viscous damping and heat conduction, the sound energy will be consumed, thereby consuming sound energy. The utility model sets the noise reduction device with at least one stepped surface in the noise reduction cavity, so that the stepped surface and the inner wall of the noise reduction cavity form a stepped cavity, then along the sound wave flow direction in the noise reduction cavity, the stepped cavity has different widths, during the flow process of the sound wave in the stepped cavity, due to the cross-section change of the stepped cavity, the sound energy can be dissipated when the sound wave passes through the variable cross-section area, the noise is reduced, thereby adapting to the noise frequency band characteristics of the range hood, solving the problem that the noise reduction cavity noise frequency band is single, improving the noise reduction effect of the range hood.

[0021] The oil smoke machine provided by the utility model comprises a noise reduction cavity, a volute and the noise reduction device. The noise reduction cavity is installed on the coaming of the volute, the coaming is provided with micro-perforations, the micro-perforations are communicated with the noise reduction cavity, and the noise reduction device is arranged in the noise reduction cavity. The utility model sets the noise reduction device with at least one stepped surface in the noise reduction cavity of the oil smoke machine, so that the sound wave needs to pass through the variable cross-section area during the flowing process in the noise reduction cavity, and the sound energy can be dissipated, thereby solving the problem of single noise reduction frequency band of the noise reduction cavity and improving the noise reduction effect of the oil smoke machine. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is the structural schematic view of the noise reduction device provided by the utility model embodiment;

[0023] Figure 2 is the structural schematic view of the stepped plate provided by the utility model embodiment;

[0024] Figure 3 is the structural schematic view of the partition plate assembly provided by the utility model embodiment;

[0025] Figure 4 is the assembly schematic view of the noise reduction device and the noise reduction cavity provided by the utility model embodiment;

[0026] Figure 5 is the structural schematic view of the noise reduction cavity provided by the utility model embodiment;

[0027] Figure 6 is the partial structural schematic view of the oil smoke machine provided by the utility model embodiment;

[0028] Figure 7 is the partial exploded structural schematic view of the oil smoke machine provided by the utility model embodiment;

[0029] Figure 8 is the local assembly schematic view of the noise reduction cavity and the volute provided by the utility model embodiment.

[0030] In the drawing:

[0031] 1, stepped plate; 11, slit;

[0032] 2, partition plate assembly; 21, frame; 211, first side plate; 212, second side plate; 213, second partition plate; 22, first partition plate;

[0033] 10, noise reduction device; 100, inner cavity; 1001, sub-inner cavity;

[0034] 20, noise reduction cavity; 201, cavity part; 2011, limiting protrusion; 2012, limiting groove; 202, arc-shaped side wall; 2021, mounting groove;

[0035] 30, fixing assembly; 301, first connecting piece; 3011, abutting end; 3012, connecting end; 302, second connecting piece;

[0036] 40, volute; 401, baffle; 4011, micro-perforation. DETAILED DESCRIPTION

[0037] In order to make the technical problems solved by the utility model, the technical scheme adopted and the technical effects reached more clear, the technical scheme of the utility model will be further explained below in combination with the drawings and through specific embodiments. It can be understood that the specific embodiments described herein are only used to explain the utility model, but not limit the utility model. In addition, it needs to be explained that, in order to facilitate the description, only the parts related to the utility model are shown in the drawings, not all.

[0038] In the description of the utility model, unless explicitly defined and limited, the terms "connected", "connected", "fixed" should be understood broadly, for example, it can be fixedly connected, or detachably connected, or integrated; it can be mechanically connected, or electrically connected; it can be directly connected, or indirectly connected through an intermediate medium, it can be the communication inside two elements or the interaction relationship of two elements. For ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0039] In the utility model, unless explicitly defined and limited, the first feature "on" or "below" the second feature can include that the first and second features are in direct contact, or the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the first feature "on", "above" and "above" the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0040] In the description of the embodiment, the terms "up", "down", "left", "right" and other orientation or position relationship are based on the orientation or position relationship shown in the drawings, only for the convenience of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore, it cannot be understood as a limitation on the utility model. In addition, the terms "first", "second" are only used to distinguish in description, and have no special meaning.

[0041] The technical scheme of the utility model will be further explained below in combination with the drawings and through specific embodiments.

[0042] AsFigures 1 to 4 As shown, this embodiment provides a noise reduction device 10, which is disposed within the noise reduction cavity 20 of a range hood. The noise reduction cavity 20 is mounted on the enclosure plate 401 of the volute 40 of the range hood. The enclosure plate 401 has micro-perforations 4011, which communicate with the noise reduction cavity 20. The noise reduction device 10 has at least one stepped surface, forming a stepped cavity between the stepped surface and the inner wall of the noise reduction cavity 20. The width of the stepped cavity increases along the direction of sound wave flow within the noise reduction cavity 20. In specific implementation, airflow within the volute 40 can flow into the noise reduction cavity 20 through the noise reduction holes. When the frequency of the incoming sound wave approaches the natural frequency of the noise reduction hole, the air column within the noise reduction hole will vibrate strongly. The air vibrates and rubs against the inner wall of the noise reduction hole. Due to viscous damping and thermal conductivity, sound energy is lost, thus consuming sound energy. This embodiment uses a noise reduction device 10 with a stepped surface to form a stepped cavity inside the noise reduction cavity 20. The stepped cavity has different widths along the direction of sound wave flow in the noise reduction cavity 20. During the flow of sound waves in the stepped cavity, the sound energy can be dissipated as the cross-section of the stepped cavity changes, thus reducing noise. This can adapt to the noise frequency band characteristics of the range hood and solve the problem of the single noise reduction frequency band of the noise reduction cavity 20.

[0043] In this embodiment, along the flow direction of sound waves within the noise reduction cavity 20, the stepped cavity includes multiple cavities connected in sequence, and the depth of a single cavity is H1, where 40mm≤H1≤50mm. In specific implementation, the number of cavities can be adjusted according to the internal dimensions of the noise reduction cavity 20 and the sound energy dissipation simulation results of different types of range hoods in order to achieve the best noise reduction effect.

[0044] Optionally, such as Figure 4 As shown, there are two noise reduction devices 10, which are arranged opposite each other. The gap between the two noise reduction devices 10 forms a stepped cavity, and the surfaces of the two noise reduction devices 10 facing each other are stepped surfaces. In specific implementation, the dimensions of the sound wave flow direction of the two noise reduction devices 10 in the vertical noise reduction cavity 20 can be the same or different. The gap between two adjacent noise reduction devices 10, that is, the width L of the multiple cavities, can also be adjusted according to the internal dimensions of the noise reduction cavity 20 and the sound energy dissipation simulation results of different types of range hoods in order to achieve the best noise reduction effect.

[0045] Optionally, such as Figures 1 to 3As shown, the noise reduction device 10 comprises the stepped plate 1 and the baffle assembly 2, the baffle assembly 2 comprises a frame 21, the frame 21 comprises a first side plate 211 and a second side plate 212 arranged at an angle, the first side plate 211 abuts the inner side wall of the noise reduction cavity 20, and the stepped plate 1 is connected between the first side plate 211 and the second side plate 212. In this embodiment, the first side plate 211 and the second side plate 212 of the noise reduction device 10 are both flat plates, and the first side plate 211 abuts the inner side wall of the noise reduction cavity 20, that is, one noise reduction device 10 has only one stepped surface, and therefore each noise reduction device 10 needs to be arranged to abut the inner side wall of the noise reduction cavity 20, so that the stepped cavities are formed between the opposite stepped surfaces of the two noise reduction devices 10 and the inner bottom wall of the noise reduction cavity 20.

[0046] In another embodiment, if the first side plate 211 of the noise reduction device 10 is also a stepped structure, the first side plate 211 and the inner side wall of the noise reduction cavity 20 can also form a stepped gap, that is, one noise reduction device 10 can form two stepped cavities, which can also solve the problem of single noise reduction frequency band of the noise reduction cavity 20. In another embodiment, if one noise reduction device 10 is arranged, the stepped surface of the noise reduction device 10, the inner side wall of the noise reduction cavity 20 which is not abutted by the noise reduction device 10, and the inner bottom wall of the noise reduction cavity 20 can also form a stepped cavity.

[0047] Further, as shown, Figure 4 The noise reduction device 10 has an inner cavity 100, a slit 11 is arranged on the stepped surface, the slit 11 is in communication with the inner cavity 100, a first baffle 22 is arranged in the inner cavity 100, the first baffle 22 has a gap with the inner wall of the noise reduction cavity 20, and the projection of the first baffle 22 along the depth direction of the slit 11 covers the slit 11. In specific implementation, because the slit 11 is opened on the stepped plate 1, the acoustic impedance changes when the sound wave passes through this area, part of the sound wave can enter the inner cavity 100 through the slit 11, and flow in the inner cavity 100 and be reflected by the first baffle 22 and the wall of the inner cavity 100, which makes the sound energy further dissipate, thereby effectively reducing the noise generated at the volute 40.

[0048] Optionally, as shown, Figure 4As shown, multiple first partitions 22 are provided, and the multiple first partitions 22 are spaced apart along the depth direction of the slit 11. In this embodiment, the frame 21 also includes a second partition 213, which is connected to the first side plate 211 to divide the inner cavity 100 into multiple sub-cavities 1001, and each sub-cavity 1001 communicates with at least one slit 11. In specific implementation, the second partition 213 is arranged perpendicularly to the first partition 22, and the first partition 22 is disposed on the second partition 213 or the second side plate 212. Two adjacent first partitions 22 in the same sub-cavity 1001 are staggered in the depth direction of the slit 11 so that the sound waves entering the sub-cavity 1001 can be reflected multiple times by the multiple first partitions 22 when flowing in the sub-cavity 1001. In other embodiments, the frame 21 may not include the second partition 213, and the first partition 22 may be fixed on the inner wall of the noise reduction cavity 20. The sound waves that enter the inner cavity 100 through a certain slit 11 can also be reflected by the first partition 22 that does not cover the slit 11, which can also achieve the effect of losing sound energy.

[0049] Preferably, the distance between two adjacent first partitions 22 in the depth direction of the slit 11 is D1, where 40mm≤D1≤50mm.

[0050] Preferably, the width of the slit 11 in the direction of sound wave flow within the noise reduction cavity 20 is D2, where 2mm≤D2≤3mm.

[0051] like Figures 5 to 8 As shown, this embodiment also provides a range hood, including a noise reduction cavity 20, a volute 40, and the aforementioned noise reduction device 10. The noise reduction cavity 20 is mounted on a surrounding plate 401 of the volute 40. Micro-perforations 4011 are provided on the surrounding plate 401, communicating with the noise reduction cavity 20. The noise reduction device 10 is disposed within the noise reduction cavity 20. Because the noise reduction device 10 in this embodiment has at least one stepped surface, the sound waves need to pass through a variable cross-section region during their flow within the noise reduction cavity 20, thus dissipating the sound energy. This solves the problem of the noise reduction cavity 20 having a single noise reduction frequency band.

[0052] Optionally, such as Figure 5As shown, the inner bottom wall of the noise reduction cavity 20 is provided with a limiting protrusion 2011, a limiting groove 2012 is formed between the limiting protrusion 2011 and the inner side wall of the noise reduction cavity 20, and the noise reduction device 10 is inserted into the limiting groove 2012 and abuts against the inner side wall of the noise reduction cavity 20. In this embodiment, the noise reduction device 10 is composed of the frame 21 and the stepped plate 1 to form a right-angled trapezoidal structure with the bevel being a stepped surface. The short side part of the right-angled trapezoidal structure is inserted into the limiting groove 2012 to limit the installation position of the noise reduction device 10 in the noise reduction cavity 20, so as to avoid the gap between the first side plate 211 of the noise reduction device 10 and the inner side wall of the noise reduction cavity 20 and thus the noise. In specific implementation, the height of the limiting protrusion 2011 can be adjusted according to the position of the slit 11 and the size of the noise reduction device 10.

[0053] Optionally, as shown in Figure 7 and Figure 8 , the range hood further comprises a fixing assembly 30, the outer side wall of the noise reduction cavity 20 is provided with a mounting groove 2021, the fixing assembly 30 comprises a first connecting piece 301 and a second connecting piece 302 which are detachably connected through a fastener, the first connecting piece 301 and the second connecting piece 302 are both slidingly inserted into the mounting groove 2021, and the ends of the first connecting piece 301 and the second connecting piece 302 which are not connected to each other can abut against the volute 40. In specific implementation, the first connecting piece 301 and the second connecting piece 302 can be provided in a Z-shaped structure, one end of the Z-shaped structure is a connecting end 3012, the other end of the Z-shaped structure is an abutting end 3011, and a connecting hole is provided on the connecting end 3012. When the first connecting piece 301 and the second connecting piece 302 are both inserted into the mounting groove 2021, the abutting ends 3011 of the first connecting piece 301 and the second connecting piece 302 are moved to abut against the two side plates of the volute 40 respectively, and then the fastener is passed through the connecting holes of the first connecting piece 301 and the second connecting piece 302 to tighten and fix the first connecting piece 301 and the second connecting piece 302, so that the abutting ends 3011 of the first connecting piece 301 and the second connecting piece 302 abut against the side plates of the volute 40, thereby realizing the fixation of the noise reduction cavity 20, the fixing assembly 30 and the volute 40.

[0054] Optionally, the mounting groove 2021 is a necked groove with both ends through, which is used to limit the first connecting piece 301 and the second connecting piece 302 to be inserted into the mounting groove 2021 only along the length direction of the necked groove, i.e. the thickness direction of the volute 40, so as to avoid the first connecting piece 301 and the second connecting piece 302 from being separated from the volute 40 in the radial direction when the first connecting piece 301 and the second connecting piece 302 are fixed, and to ensure the installation effect.

[0055] As shown in Figure 7As shown, the noise reduction cavity 20 comprises a connected cavity part 201 and two arc-shaped side walls 202, that is, one end of the cavity part 201 is connected with one arc-shaped side wall 202, the other end of the cavity part 201 is connected with the other arc-shaped side wall 202, and the arc-shaped side wall 202 extends along the circumference of the volute 40 and abuts against the outer circumferential surface of the surrounding plate 401, so that when the noise reduction cavity 20 is fixed on the surrounding plate 401, the connection between the noise reduction cavity 20 and the volute 40 can be ensured to be sealed well.

[0056] In the embodiment, the mounting groove 2021 is arranged at the arc-shaped side wall 202, two groups of the fixing assembly 30 are arranged, and one group of the fixing assembly 30 is arranged in the mounting groove 2021 of one arc-shaped side wall 202, so that the two arc-shaped side walls 202 of the noise reduction cavity 20 are connected with the volute 40 by the fixing assembly 30, so as to facilitate the disassembly and assembly of the noise reduction cavity 20. In other embodiments, the catch can be arranged on one arc-shaped side wall 202, the clamping groove is arranged on the surrounding plate 401 abutting against the catch, and the mounting groove 2021 and the fixing assembly 30 are arranged on the other arc-shaped side wall 202. In specific implementation, the catch can be first hooked into the clamping groove, and then the other arc-shaped side wall 202 and the volute 40 are locked by the fixing assembly 30, so that the detachable connection between the noise reduction cavity 20 and the volute 40 can be achieved.

[0057] The above embodiments only illustrate the basic principles and characteristics of the present application, and the present application is not limited by the above embodiments. Without departing from the spirit and scope of the present application, various changes and modifications can be made to the present application, and these changes and modifications all fall within the scope of the present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. Noise reduction device, characterized in that The noise reduction device (10) is arranged in a noise reduction cavity (20) of the range hood, the noise reduction cavity (20) is mounted on a baffle (401) of a volute (40) of the range hood, a micro-perforation (4011) is arranged on the baffle (401), and the micro-perforation (4011) communicates with the noise reduction cavity (20). The noise reduction device (10) has at least one stepped surface, a stepped cavity is formed between the stepped surface and an inner wall of the noise reduction cavity (20), and the width of the stepped cavity is enlarged along the sound wave flow direction in the noise reduction cavity (20).

2. The noise reducing device of claim 1, wherein, Along the sound wave flow direction in the noise reduction cavity (20), the stepped cavity includes a plurality of cavities that are sequentially communicated, and the depth of a single cavity is H1, 40mm≤H1≤50mm.

3. The noise reducing device of claim 1, wherein, The noise reduction device (10) has two, two noise reduction devices (10) are oppositely arranged, a space between the two noise reduction devices (10) forms the stepped cavity, and opposite surfaces of the two noise reduction devices (10) are the stepped surfaces.

4. The noise reducing device of claim 1, wherein, The noise reduction device (10) includes a stepped plate (1) and a partition plate assembly (2), the partition plate assembly (2) includes a frame (21), the frame (21) includes a first side plate (211) and a second side plate (212) that are arranged at an included angle, the first side plate (211) abuts an inner side wall of the noise reduction cavity (20), and the stepped plate (1) is connected between the first side plate (211) and the second side plate (212).

5. The noise reducing device of claim 1, wherein, The noise reduction device (10) has an inner cavity (100), a slit (11) is arranged on the stepped surface, the slit (11) communicates with the inner cavity (100), a first partition plate (22) is arranged in the inner cavity (100), the first partition plate (22) has a space with an inner wall of the noise reduction cavity (20), and a projection of the first partition plate (22) along the depth direction of the slit (11) covers the slit (11).

6. The noise reducing device of claim 5, wherein, A plurality of first partition plates (22) are arranged at intervals along the depth direction of the slit (11).

7. A range hood characterized by The noise reduction device (10) includes a noise reduction cavity (20), a volute (40) and the noise reduction device (10) according to any one of claims 1 to 6, the noise reduction cavity (20) is mounted on a baffle (401) of the volute (40), a micro-perforation (4011) is arranged on the baffle (401), the micro-perforation (4011) communicates with the noise reduction cavity (20), and the noise reduction device (10) is arranged in the noise reduction cavity (20).

8. The range hood according to claim 7, characterized in that A limiting protrusion (2011) is arranged on an inner bottom wall of the noise reduction cavity (20), a limiting groove (2012) is formed between the limiting protrusion (2011) and an inner side wall of the noise reduction cavity (20), and the noise reduction device (10) is inserted into the limiting groove (2012) and abuts the inner side wall of the noise reduction cavity (20).

9. The range hood according to claim 7, characterized in that The range hood further comprises a fixing assembly (30), an outer side wall of the noise reduction cavity (20) is provided with a mounting groove (2021) penetrating through two ends, the fixing assembly (30) comprises a first connecting piece (301) and a second connecting piece (302) which are detachably connected through fasteners, the first connecting piece (301) and the second connecting piece (302) are both slidingly inserted into the mounting groove (2021), and one end of the first connecting piece (301) and the second connecting piece (302) which are not connected with each other can abut against the volute (40).

10. The range hood according to claim 9, characterized in that The noise reduction cavity (20) comprises a cavity part (201) and two arc-shaped side walls (202) connected, the arc-shaped side walls (202) extend along the circumference of the volute (40) and abut against the baffle (401), the mounting groove (2021) is arranged on the arc-shaped side wall (202), and at least one set of the fixing assembly (30) is arranged in the mounting groove (2021) of one arc-shaped side wall (202).

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