Volute tongue assembly, centrifugal fan and range hood

Abstract

The utility model discloses a volute tongue assembly, a centrifugal fan and a range hood. The volute tongue assembly comprises a volute tongue body, a positioning part and a mounting part, the positioning part is arranged on one side of the volute tongue body; the mounting part is arranged on the side, away from the positioning part, of the volute tongue body and connected with the positioning part; wherein the volute tongue body is integrally formed with the positioning part and the mounting part respectively. In this way, according to the volute tongue assembly, the volute tongue body, the positioning part and the mounting part are integrally formed, so that the machining size of integral forming can be reduced, and machining adjustment can be conveniently conducted on the area, with the small size or the large depth, of the volute tongue body in the integral forming process; the machining difficulty and the machining cost of the volute tongue assembly are reduced, and the machining precision of the volute tongue assembly is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the fan technical field, in particular to volute tongue assembly, centrifugal fan and range hood. BACKGROUND

[0002] The centrifugal fan is a kind of equipment for accelerating, then decelerating, changing flow direction by high-speed rotating impeller, and makes kinetic energy into potential energy.The centrifugal fan usually uses volute tongue assembly to change the flow direction of air flow, specifically by the gap between volute tongue assembly and centrifugal impeller is much smaller than the flow area of upstream, so that air flow is blocked in volute tongue assembly, and then plays the role of changing the flow direction of air flow.

[0003] The volute tongue assembly of the existing centrifugal fan is usually integrally formed with the volute shroud of volute assembly.In the production of volute assembly, volute shroud and volute tongue assembly are formed at one time, and then the formed volute shroud is welded with the front and rear plates of volute assembly.However, due to the special structure of volute tongue assembly, when the size of volute tongue assembly is small and the depth is large, the integrally formed process of volute shroud and volute tongue assembly is difficult to process, resulting in high processing cost and low processing precision of volute tongue assembly. UTILITY MODEL CONTENT

[0004] In order to solve the above problems existing in the prior art, the present application provides a volute tongue assembly, a centrifugal fan and a range hood.

[0005] To solve the technical problems existing in the prior art, the present application provides a first technical solution: a volute tongue assembly is provided, which is applied to a centrifugal fan, and the volute tongue assembly comprises a volute tongue body, a positioning part and a mounting part.The positioning part is arranged on one side of the volute tongue body;The mounting part is arranged on the side of the volute tongue body away from the positioning part, and the mounting part is connected with the positioning part;Wherein, the volute tongue body is integrally formed with the positioning part and the mounting part.

[0006] Optionally, the positioning part includes a first welding surface, the mounting part includes a second welding surface, the first welding surface is opposite to the second welding surface, and the first welding surface and the second welding surface are connected by welding.

[0007] Optionally, the volute tongue body, the positioning part and the mounting part form a containing space, and the containing space is closed by the connection of the mounting part and the positioning part.

[0008] Optionally, the volute tongue body is bent to form an arc surface, and the arc surface faces the mounting part and the positioning part.

[0009] Optionally, the mounting portion is provided with at least one first mounting hole, and a flange portion is arranged around the first mounting hole, and the protruding direction of the flange portion is towards the side of the mounting portion close to the volute tongue body.

[0010] To solve the technical problems in the prior art, the second technical solution provided by the present application is to provide a centrifugal fan, which comprises a volute assembly and the volute tongue assembly as described above, and the volute tongue assembly is mounted on the volute assembly.

[0011] Optionally, the centrifugal fan further comprises a fixing member, the mounting portion of the volute tongue assembly is provided with at least one first mounting hole, the volute assembly is provided with at least one second mounting hole, the first mounting hole corresponds to the second mounting hole, and the fixing member is arranged through the second mounting hole and the first mounting hole to fix the volute tongue assembly on the volute assembly.

[0012] Optionally, the volute assembly comprises a volute body and a volute surrounding plate, the volute body comprises an air inlet and an air outlet, the centrifugal fan comprises a centrifugal fan wheel, the centrifugal fan wheel is arranged at the air inlet of the volute body, the volute surrounding plate is arranged at the air outlet of the volute body, and the volute tongue assembly is fixed on the volute surrounding plate.

[0013] Optionally, the size of the volute tongue assembly is smaller than the size of the air inlet of the volute body.

[0014] To solve the technical problems in the prior art, the third technical solution provided by the present application is to provide a range hood, which comprises the centrifugal fan as described above.

[0015] The volute tongue assembly, the centrifugal fan and the range hood are provided by the present application, the volute tongue assembly comprises a volute tongue body, a positioning portion and a mounting portion, the positioning portion is arranged on one side of the volute tongue body, the mounting portion is arranged on the side of the volute tongue body away from the positioning portion, and the mounting portion is connected with the positioning portion, wherein the volute tongue body is integrally formed with the positioning portion and the mounting portion. In the above manner, the volute tongue assembly of the present application is integrally formed with the positioning portion and the mounting portion through the volute tongue body, so that the processing size of the integral forming can be reduced, the area with smaller size or larger depth of the volute tongue body can be processed and adjusted during the integral forming, the processing difficulty and cost of the volute tongue assembly can be reduced, and the processing precision of the volute tongue assembly can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0017] Figure 1 is a structural schematic diagram of a first embodiment of the volute tongue assembly provided in the present application;

[0018] Figure 2 is a structural schematic diagram of a second embodiment of the volute tongue assembly provided in the present application;

[0019] Figure 3 is a structural schematic diagram of an embodiment of the centrifugal fan provided in the present application;

[0020] Figure 4 is a structural schematic diagram of an embodiment of the centrifugal fan provided in the present application; Figure 3 is a structural exploded view of the centrifugal fan in

[0021] In the figure, 1, centrifugal fan; 10, volute tongue assembly; 110, volute tongue body; 111, circular arc surface; 120, positioning portion; 121, first welding surface; 130, mounting portion; 131, second welding surface; 132, first mounting hole; 20, volute assembly; 210, volute body; 211, air inlet; 212, air outlet; 220, volute surrounding plate; 30, centrifugal impeller; 40, air guide ring; 50, driving member. DETAILED DESCRIPTION

[0022] The present application will be further described below in conjunction with the accompanying drawings and embodiments. It is particularly pointed out that the following embodiments are only for illustrating the present application, but not for limiting the scope of the present application. Similarly, the following embodiments are only part of the embodiments of the present application, but not all the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the scope of protection of the present application.

[0023] In this text, the phrase "embodiment" means that the specific features, structures or characteristics described in conjunction with the embodiment can be included in at least one embodiment of the present application. The phrase appears at various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment to other embodiments. Those skilled in the art explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0024] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "setting", "connecting", "connecting" should be understood broadly, for example, it can be fixedly connected, it can be detachably connected, or integrally connected; it can be mechanically connected, or electrically connected; it can be directly connected, or connected through an intermediate medium. For those skilled in the art, if the present application has any directional indication (such as up, down, left, right, front, back, etc.), the directional indication is only used to explain the relative position relationship, movement condition, etc. between the components in a certain posture (as shown in the drawings), if the certain posture changes, the directional indication will also change accordingly.

[0025] Please refer to Figure 1 and Figure 2 , Figure 1 is a structural schematic diagram of a first embodiment of a volute tongue assembly provided by the present application, Figure 2 is a structural schematic diagram of a second embodiment of a volute tongue assembly provided by the present application. As shown in Figure 1 and Figure 2 , the volute tongue assembly 10 of the present embodiment is applied to a centrifugal fan 1, specifically, the volute tongue assembly 10 is detachably mounted on a volute shell assembly 20 of the centrifugal fan 1, and the volute tongue assembly 10 can be detachably mounted by means of bolts, buckles, pins, flanges, etc. but is not limited thereto.

[0026] The volute tongue assembly 10 comprises a volute tongue body 110, a positioning portion 120, and a mounting portion 130. The positioning portion 120 is arranged on one side of the volute tongue body 110; the mounting portion 130 is arranged on the side of the volute tongue body 110 away from the positioning portion 120, and the mounting portion 130 is connected with the positioning portion 120; and the volute tongue body 110 is integrally formed with the positioning portion 120 and the mounting portion 130.

[0027] Specifically, the volute tongue body 110 of the volute tongue assembly 10 is usually formed with a circular arc surface 111, which is used to guide the airflow inside the volute shell assembly 20. When the airflow sweeps across the circular arc surface 111 of the volute tongue body 110, the volute tongue body 110 guides most of the airflow to the air outlet 212 of the volute shell assembly 20, so as to improve the efficiency of the gas flow of the centrifugal fan 1. The positioning portion 120 is arranged on one side of the circular arc surface 111 of the volute tongue body 110, and the mounting portion 130 is arranged on the other side of the circular arc surface 111 of the volute tongue body 110. The positioning portion 120 is used to realize the auxiliary positioning of the volute tongue assembly 10, and the mounting portion 130 is used to realize the mounting connection of the volute tongue assembly 10 with the volute shell assembly 20. Among them, the positioning portion 120 and the mounting portion 130 can be but are not limited to flat surfaces in the form of plates, so as to facilitate auxiliary positioning and mounting.

[0028] Further, the connection mode of the mounting portion 130 and the positioning portion 120 includes but is not limited to that the edges of the mounting portion 130 and the positioning portion 120 are connected by welding, for example, the edges of the mounting portion 130 and the positioning portion 120 can be connected by fusion welding, pressure welding, solid-state welding, etc.; the edges of the mounting portion 130 and the positioning portion 120 are connected by bolting; the edges of the mounting portion 130 and the positioning portion 120 are connected by riveting; the edges of the mounting portion 130 and the positioning portion 120 are connected by adhesion; the edges of the mounting portion 130 and the positioning portion 120 are externally pressed; the edges of the mounting portion 130 and the positioning portion 120 are connected by hot melting; and the edges of the mounting portion 130 and the positioning portion 120 are fixedly connected by mechanical structures such as clamps and clamps.

[0029] Understandably, the volute tongue body 110 is integrally formed with the positioning portion 120 and the mounting portion 130, so that before the mounting portion 130 is connected with the positioning portion 120, the internal containing space formed by the combination of the volute tongue body 110, the positioning portion 120 and the mounting portion 130 can be communicated with the outside through the gap between the positioning portion 120 and the mounting portion 130; after the mounting portion 130 is connected with the positioning portion 120, the internal containing space of the volute tongue body 110, the positioning portion 120 and the mounting portion 130 is closed, so that the volute tongue assembly 10 forms a closed structure, when the airflow passes through the volute tongue assembly 10, the airflow will not pass through the volute tongue assembly 10, but will be guided to the air outlet 212 of the volute casing assembly 20 through the volute tongue assembly 10.

[0030] In the embodiment of the present application, the volute tongue assembly 10 includes a volute tongue body 110, a positioning portion 120 and a mounting portion 130; the positioning portion 120 is arranged on one side of the volute tongue body 110; the mounting portion 130 is arranged on the side of the volute tongue body 110 away from the positioning portion 120, and the mounting portion 130 is connected with the positioning portion 120; wherein the volute tongue body 110 is integrally formed with the positioning portion 120 and the mounting portion 130. By the above-mentioned mode, the volute tongue assembly 10 of the present application is integrally formed with the positioning portion 120 and the mounting portion 130 through the volute tongue body 110, so that the processing size of the integral molding can be reduced, the area with smaller size or larger depth of the volute tongue body 110 can be processed and adjusted during the integral molding, which is beneficial to reduce the processing difficulty and processing cost of the volute tongue assembly 10 and improve the processing precision of the volute tongue assembly 10.

[0031] In an embodiment, the positioning portion 120 includes a first welding surface 121, the mounting portion 130 includes a second welding surface 131, the first welding surface 121 is opposite to the second welding surface 131, and the first welding surface 121 and the second welding surface 131 are connected by welding.

[0032] Specifically, the first welding surface 121 of the positioning portion 120 and the second welding surface 131 of the mounting portion 130 are connected by welding, so that the connection position of the first welding surface 121 and the second welding surface 131 forms a welding seam, realizing the fixed connection of the positioning portion 120 and the mounting portion 130, which is beneficial to improve the overall strength and machining precision of the volute tongue assembly 10 and improve the service life of the volute tongue assembly 10.

[0033] Optionally, an accommodation space is formed between the volute tongue body 110, the positioning portion 120, and the mounting portion 130, and the accommodation space is closed by the connection of the mounting portion 130 and the positioning portion 120.

[0034] Specifically, an accommodation space is formed between the volute tongue body 110, the positioning portion 120, and the mounting portion 130, and after the mounting portion 130 and the positioning portion 120 are connected by welding, the accommodation space inside the volute tongue body 110, the positioning portion 120, and the mounting portion 130 is closed by the welding seam, so that the volute tongue assembly 10 forms a closed structure. When the airflow sweeps through the volute tongue assembly 10, the airflow cannot pass through the volute tongue assembly 10, but is guided to the air outlet 212 of the volute shell assembly 20 through the volute tongue assembly 10, which is beneficial to improve the airflow stability of the volute tongue assembly 10 and further improve the overall performance of the centrifugal fan 1.

[0035] In an embodiment, the volute tongue body 110 is bent to form a circular arc surface 111, and the circular arc surface 111 faces the mounting portion 130 and the positioning portion 120.

[0036] Specifically, the volute tongue body 110 is bent to form a circular arc surface 111. One side of the circular arc surface 111 forms a boss extending outward, and the other side of the circular arc surface 111 is a groove side corresponding to the boss. The protruding direction of the boss is opposite to the direction of the circular arc surface 111, that is, the direction of the circular arc surface 111 is the direction faced by the groove side of the circular arc surface 111. The circular arc surface 111 faces the mounting portion 130 and the positioning portion 120, which means that the groove side of the circular arc surface 111 faces the mounting portion 130 and the positioning portion 120, and the boss of the circular arc surface 111 extends outward and faces away from the mounting portion 130 and the positioning portion 120. Therefore, when the volute tongue assembly 10 is installed on the volute shell assembly 20 through the mounting portion 130, the boss of the circular arc surface 111 of the volute tongue body 110 faces outward, so that the airflow inside the volute shell assembly 20 can flow towards the position of the boss and contact the boss, and then be guided to the air outlet 212 of the volute shell assembly 20 under the shape of the boss. Therefore, the bending arrangement of the volute tongue body 110 in this embodiment is beneficial to improve the airflow stability of the volute tongue assembly 10 and further improve the overall performance of the centrifugal fan 1.

[0037] In an embodiment, at least one first mounting hole 132 is arranged on the mounting portion 130, and a flange portion is arranged around the first mounting hole 132, and the protruding direction of the flange portion is towards the side of the mounting portion 130 close to the volute tongue body 110.

[0038] Specifically, the first mounting hole 132 on the mounting portion 130 is processed by a flanging process, and therefore, the mounting portion 130 forms a flange portion around the first mounting hole 132, and the protruding direction of the flange portion of the first mounting hole 132 is towards the side of the mounting portion 130 close to the volute tongue body 110, that is, the protruding direction of the flange portion is opposite to the direction of the circular arc surface 111, so as to facilitate further processing of the flange portion and further improve the processing precision of the volute tongue assembly 10.

[0039] Please refer to Figure 3 and Figure 4 , Figure 3 is a structural schematic diagram of an embodiment of the centrifugal fan provided in the application, Figure 4 is Figure 3 is an exploded view of the structure of the centrifugal fan in Figure 3 and Figure 4 , the centrifugal fan 1 of the embodiment includes a volute assembly 20 and the volute tongue assembly 10 of any one of the above embodiments, and the volute tongue assembly 10 is installed on the volute assembly 20.

[0040] Specifically, the volute assembly 20 is usually provided with an air inlet 211 and an air outlet 212, the volute assembly 20 is used to collect gas through the air inlet 211 and guide the gas to the air outlet 212, so that the kinetic energy of the gas is partially converted into static pressure energy in the process of flowing from the air inlet 211 to the air outlet 212, forming wind pressure, and then realizing the functions of ventilation, air guiding and the like of the fan through the wind pressure. The volute tongue assembly 10 is installed on the volute assembly 20, specifically near the air outlet 212 of the volute assembly 20, and the volute tongue assembly 10 is used to divide the flow channel near the air outlet 212 into two flow channels, so that the gas in the volute assembly 20 is discharged through the two flow channels.

[0041] In the embodiment of the application, the volute tongue assembly 10 of the embodiment is installed on the volute assembly 20, which is different from the scheme of integrally forming the volute tongue assembly 10 and the volute assembly 20 in the prior art. The centrifugal fan 1 of the embodiment separates the volute tongue assembly 10 and the volute assembly 20 with high processing difficulty, integrally forms the volute tongue body 110 of the volute tongue assembly 10 with the mounting portion 130 and the positioning portion 120 respectively, so as to improve the processing precision of the volute tongue assembly 10, and is beneficial to the subsequent installation and maintenance of the volute tongue assembly 10, and further improves the practicability of the centrifugal fan 1.

[0042] In an embodiment, the centrifugal fan 1 further comprises a fixing member, the mounting portion 130 of the volute tongue assembly 10 is provided with at least one first mounting hole 132, the volute shell assembly 20 is provided with at least one second mounting hole, the first mounting hole 132 corresponds to the second mounting hole, and the fixing member is arranged in the second mounting hole and the first mounting hole 132 to fix the volute tongue assembly 10 to the volute shell assembly 20.

[0043] Specifically, the mounting portion 130 of the volute tongue assembly 10 can be mounted on the volute shell assembly 20 through the fixing member. The mounting portion 130 of the volute tongue assembly 10 is provided with the first mounting hole 132, and the volute shell assembly 20 is also provided with the second mounting hole at the corresponding mounting position of the volute tongue assembly 10. The shape, size and number of the first mounting hole 132 correspond to those of the second mounting hole, so that the fixing member can be arranged in the second mounting hole and the first mounting hole 132, thereby realizing the fixed connection between the volute tongue assembly 10 and the volute shell assembly 20. In possible embodiments, the fixing member includes but is not limited to a bolt, a rivet, a pin, a flange and other fixing components for realizing detachable connection.

[0044] In the above manner, the centrifugal fan 1 of the embodiment can fix the volute tongue assembly 10 to the volute shell assembly 20 through the fixing member, realize detachable mounting of the volute tongue assembly 10, facilitate subsequent installation and maintenance of the volute tongue assembly 10 while improving the machining precision of the volute tongue assembly 10, and further improve the practicability of the centrifugal fan 1.

[0045] Optionally, the volute shell assembly 20 comprises a volute shell body 210 and a volute shell baffle 220. The volute shell body 210 comprises an air inlet 211 and an air outlet 212. The centrifugal fan 1 comprises a centrifugal impeller 30. The centrifugal impeller 30 is arranged at the air inlet 211 of the volute shell body 210. The volute shell baffle 220 is arranged at the air outlet 212 of the volute shell body 210. The volute tongue assembly 10 is fixed to the volute shell baffle 220.

[0046] Specifically, the volute shell body 210 of the volute shell assembly 20 is provided with an air duct for airflow, so as to form the air inlet 211 and the air outlet 212 along the airflow direction. The centrifugal impeller 30 of the centrifugal fan 1 is arranged near the air inlet 211 of the volute shell assembly 20. The centrifugal impeller 30 is rotationally connected to the volute shell body 210. The centrifugal impeller 30 blows air into the air inlet 211 through rotation, so that the air enters the air duct and flows along the air duct. The flowing air flows to the air outlet 212 near the volute shell baffle 220 and contacts the volute tongue assembly 10 on the volute shell baffle 220. The volute tongue assembly 10 is used to divide the flowing air into two parts, so as to form a first flow channel and a second flow channel. Most of the air in the air duct flows to the air outlet 212 through the first flow channel. Another part of the air in the air duct flows back to the volute shell body 210 through the second flow channel, so as to flow in the volute shell body 210 for internal circulation and participate in new flow division with the newly entered air through the air inlet 211.

[0047] In this way, the volute tongue assembly 10 can be fixed to the volute shroud 220 through the air outlet 212, and during maintenance and installation of the volute tongue assembly 10, the centrifugal fan 1 does not need to be disassembled, but can be directly installed and maintained through the air outlet 212, thereby improving the convenience of installation and maintenance and improving the practicability of the centrifugal fan 1.

[0048] Further, the size of the volute tongue assembly 10 is smaller than the size of the air inlet 211 of the volute body 210.

[0049] Specifically, the centrifugal fan 1 can further include a wind guide ring 40, which is installed on the outer surface of the volute body 210 and corresponds to the air inlet 211, and is used to uniformly introduce external gas into the centrifugal fan 30 to reduce the flow loss of the gas. When the air inlet 211 is provided, the volute body 210 needs to be cut at the position corresponding to the air inlet 211 to form the air inlet 211. In this embodiment, since the size of the volute tongue assembly 10 is smaller than the size of the air inlet 211 of the volute body 210, the volute tongue assembly 10 can be processed from the waste material cut off when the air inlet 211 is provided on the volute body 210, thereby further reducing the processing cost of the volute tongue assembly 10 and improving the waste utilization rate of the centrifugal fan 1.

[0050] In this embodiment, since the volute tongue body 110 of the volute tongue assembly 10 is integrally formed with the mounting portion 130 and the positioning portion 120, the size of the volute tongue assembly 10 can be understood as the combined size of the volute tongue body 110, the mounting portion 130 and the positioning portion 120. The size of the air inlet 211 is used to represent the cutting size when the volute body 210 is cut to form the air inlet 211.

[0051] In an embodiment, the centrifugal fan 1 can further include a driving member 50, which can be installed on the volute body 210 of the volute assembly 20 or the wind guide ring 40, and corresponds to the air inlet 211 and is used to drive the centrifugal fan 30 to rotate.

[0052] The application also provides a range hood, which includes the centrifugal fan 1 according to any one of the above embodiments. Specifically, the range hood generates strong suction through the centrifugal fan 1 to further suck the oil smoke and steam at the corresponding position of the air inlet 211, thereby reducing the pollution of the oil smoke to indoor air and the environment.

[0053] In other embodiments, the centrifugal fan 1 according to the application can also be applied to laundry treatment equipment such as a dryer, air circulation and purification equipment, a ventilation system, a refrigerator and other equipment, and is used to assist air and gas flow, which is not limited here.

[0054] The above merely provides the implementation of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation, or direct or indirect application in other related technical fields, which is made according to the content of the present application and the accompanying drawings, is also included in the patent protection scope of the present application.

Claims

1. A volute tongue assembly, characterized by, The volute tongue assembly is applied to a centrifugal fan, and comprises: a volute tongue body; a positioning portion arranged on one side of the volute tongue body; a mounting portion arranged on the side of the volute tongue body away from the positioning portion, and connected with the positioning portion; wherein the volute tongue body is integrally formed with the positioning portion and the mounting portion.

2. The vane assembly of claim 1, wherein, The positioning portion comprises a first welding surface, and the mounting portion comprises a second welding surface, the first welding surface is opposite to the second welding surface, and the first welding surface and the second welding surface are connected by welding.

3. The vane assembly of claim 2, wherein, An accommodating space is formed between the volute tongue body, the positioning portion and the mounting portion, and the accommodating space is closed by the connection of the mounting portion and the positioning portion.

4. The vane assembly of claim 1, wherein, The volute tongue body is arranged in a bending manner, so that the volute tongue body forms an arc surface, and the arc surface faces the mounting portion and the positioning portion.

5. The vane assembly of claim 1, wherein, At least one first mounting hole is arranged on the mounting portion, and a flange portion is arranged around the first mounting hole, and the protruding direction of the flange portion faces the side of the mounting portion close to the volute tongue body.

6. A centrifugal fan characterized by The volute tongue assembly comprises: a volute shell assembly; The volute tongue assembly according to any one of claims 1-5 is mounted on the volute shell assembly.

7. The centrifugal fan of claim 6, wherein The centrifugal fan further comprises a fixing member, at least one first mounting hole is arranged on the mounting portion of the volute tongue assembly, at least one second mounting hole is arranged on the volute shell assembly, the first mounting hole corresponds to the second mounting hole, and the fixing member is arranged in the second mounting hole and the first mounting hole to fix the volute tongue assembly on the volute shell assembly.

8. The centrifugal fan of claim 7, wherein The volute shell assembly comprises a volute shell body and a volute shell surrounding plate, the volute shell body comprises an air inlet and an air outlet, the centrifugal fan comprises a centrifugal fan wheel, the centrifugal fan wheel is arranged at the air inlet of the volute shell body, the volute shell surrounding plate is arranged at the air outlet of the volute shell body, and the volute tongue assembly is fixed on the volute shell surrounding plate.

9. The centrifugal fan of claim 8, wherein The size of the volute tongue assembly is smaller than the size of the air inlet of the volute shell body.

10. A range hood characterized by, The centrifugal fan according to any one of claims 6-9 is provided.

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