Centrifugal fan and range hood

Abstract

The invention relates to the technical field of household appliances, and provides a centrifugal fan and a range hood, the centrifugal fan comprises a volute, the volute is provided with a flow channel, and the flow channel extends in the spiral air outlet direction of the volute; the volute is provided with an air outlet part extending towards the radial outer side, an inlet of the air outlet part is communicated with the tail end of the flow channel, and the periphery of an outlet of the air outlet part is a smooth curve. The rapid change of the flow speed and the pressure of the gas on the surface of the inner wall of the non-smooth transition air outlet part is avoided, so that the flow separation phenomenon is reduced, and the noise generated when the gas flows out of the air outlet part and the unstable air outlet of the air outlet part are effectively reduced.

Description

Technical Field

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

[0002] Centrifugal fans have become common core power components in range hoods due to their advantages such as high suction, low noise and compact structure. The performance of the centrifugal fan itself directly determines the noise level of the range hood.

[0003] In the related art, flow separation is easily generated at the outlet of the centrifugal fan, resulting in large fluctuations in gas flow, uneven gas discharge, and a large amount of noise. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the related art. To this end, the present invention proposes a centrifugal fan that, by providing a smooth transition on the inner wall of the outlet, avoids abrupt changes in the flow velocity and pressure of the gas on the inner wall surface of the outlet where the transition is not smooth, thereby reducing the occurrence of flow separation, effectively reducing the noise generated when the gas flows out of the outlet, and reducing the problem of unstable air output from the outlet.

[0005] The present invention also provides a range hood.

[0006] A centrifugal fan according to an embodiment of the first aspect of the present invention includes:

[0007] A volute, wherein the volute is provided with a flow channel, and the flow channel extends along the spiral air outlet direction of the volute;

[0008] The volute is provided with an air outlet portion extending radially outward, the inlet of the air outlet portion is connected to the end of the flow channel, and the inner wall of the volute corresponding to the end of the flow channel and the outlet of the air outlet portion is smoothly transitioned.

[0009] According to the centrifugal fan of the embodiment of the present invention, the gas flows in the flow channel along the spiral air outlet direction, passes through the air outlet portion, and is discharged from the volute from the outlet of the air outlet portion.

[0010] In a centrifugal fan according to an embodiment of the present invention, a smooth transition is achieved from the end of the flow channel to the inner wall of the volute corresponding to the outlet of the air outlet. This prevents abrupt changes in gas velocity and pressure on the inner wall of the air outlet where the transition is not smooth, thereby reducing flow separation and effectively minimizing noise generated when gas flows out of the air outlet and any instability in the air outlet.

[0011] According to one embodiment of the present invention, the outer periphery of the outlet of the air outlet is a smooth curve.

[0012] According to one embodiment of the present invention, the centrifugal fan further includes a check valve, the check valve is provided with an air outlet channel, the inlet of the air outlet channel is connected to the outlet of the air outlet portion, and the cross-sectional area of ​​the air outlet channel gradually increases along the airflow direction.

[0013] According to one embodiment of the present invention, at least one of the outlet of the air outlet portion and the outlet of the check valve is circular.

[0014] According to one embodiment of the present invention, a volute tongue is provided on one side of the air outlet portion, the volute tongue is recessed toward the side away from the air outlet portion to form a recessed portion, and the volute tongue is suitable for diverting the gas flowing out of the flow channel.

[0015] According to an embodiment of the present invention, the recessed portion includes a smooth curved surface, and the recessed portion and the inlet of the air outlet portion form a smooth structure.

[0016] According to one embodiment of the present invention, the outlet of the air outlet has an axis, the air inlet has a center line parallel to the axis, and the volute tongue is located on a side of the center line close to the air outlet.

[0017] According to one embodiment of the present invention, the volute comprises at least two shell parts spliced ​​together, and the volute tongue is detachably connected to the shell parts.

[0018] According to one embodiment of the present invention, the volute further comprises a first connecting plate, which is provided at the end of the outlet of the air outlet portion and extends radially along the air outlet portion;

[0019] Corresponding to the first connecting plate, a second connecting plate is provided at one end of the inlet of the check valve.

[0020] A range hood according to a second embodiment of the present invention includes:

[0021] Box;

[0022] The centrifugal fan as described above is placed in the box.

[0023] The beneficial effects of the range hood according to the embodiment of the present invention are the same as the effective effects of the centrifugal fan in the embodiment of the first aspect of the present invention, and will not be repeated here.

[0024] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the following briefly introduces the drawings required for use in the embodiments or related technical descriptions. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0026] Figure 1 is a front view of a centrifugal fan provided by an embodiment of the present invention;

[0027] Figure 2 yes Figure 1 a cross-sectional view of the middle section B1-B2;

[0028] Figure 3 yes Figure 1 A cross-sectional view of the middle section A1-A2;

[0029] Figure 4 is an exploded view of a volute of a centrifugal fan provided by an embodiment of the present invention;

[0030] Figure 5 is a side view of a centrifugal fan provided by an embodiment of the present invention;

[0031] Figure 6 yes Figure 5 Cross-sectional view of the middle section CC;

[0032] Figure 7 is a top view of a centrifugal fan provided by an embodiment of the present invention without a check valve installed;

[0033] Figure 8 1 is a top view of a check valve installed in a centrifugal fan provided by an embodiment of the present invention;

[0034] Figure 9 This is a cross-sectional view of a volute of a centrifugal fan provided by an embodiment of the present invention, cut along the axis of the air outlet.

[0035] Reference numerals:

[0036] 100, volute; 110, side arc plate; 120, cover plate; 130, transition portion; 131, first transition surface; 132, second transition surface; 140, air outlet; 150, flow channel; 160, first connecting plate; 190, air inlet; 170, shell;

[0037] 300, check valve; 310, air outlet channel; 320, second connecting plate;

[0038] 400, air guide ring; 410, first air inlet channel;

[0039] 500, snail tongue; 510, depression. DETAILED DESCRIPTION

[0040] The following embodiments of the present invention are described in further detail with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0041] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", 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 the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting the embodiments of the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and should not be understood as indicating or implying relative importance.

[0042] In the description of the embodiments of the present invention, it should be noted that, unless otherwise specified or limited, the terms "connected" and "connection" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; and direct connections or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of the above terms in the embodiments of the present invention based on the specific circumstances.

[0043] In the embodiments of the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, a first feature being "above," "above," or "above" a second feature may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. A first feature being "below," "below," or "below" a second feature may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0044] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0045] Combine Figure 5 、 Figure 6 and Figure 8 As shown, the centrifugal fan according to the embodiment of the first aspect of the present invention includes a volute 100, which is provided with a flow channel 150, and the flow channel 150 extends along the spiral air outlet direction of the volute 100; the volute 100 is provided with an air outlet portion 140 extending radially outward, and the inlet of the air outlet portion 140 is connected to the end of the flow channel 150, and the inner wall of the volute 100 corresponding to the outlet of the air outlet portion 140 smoothly transitions from the end of the flow channel 150 to the outlet of the air outlet portion 140.

[0046] According to the centrifugal fan of the embodiment of the present invention, the gas flows in the flow channel 150 along the spiral air outlet direction, passes through the air outlet portion 140 , and is discharged from the volute 100 from the outlet of the air outlet portion 140 .

[0047] In the related art, the volute 100 of the centrifugal fan used in household appliances is usually a two-dimensional tensile structure, that is, along the axial direction of the air inlet 190, the circumferential cross-sections along different azimuth angles are all rectangular cross-sections. The gas will produce flow separation at the corners of the rectangle, and it is very easy to form a separation vortex area, resulting in unstable gas flow, and then generating noise, and the gas flow fluctuations affect the uniform air intake of the air inlet 190.

[0048] Among them, the main reasons for flow separation at corners include two aspects: pressure gradient and viscosity effect.

[0049] Corners typically experience large pressure gradients, which translates to significant changes in gas flow velocity. When gas flows through corners, the sudden change in geometry causes a dramatic change in both velocity and pressure, leading to unstable airflow and the potential for flow separation.

[0050] At corners, due to the interaction between the gas and the surface of the volute 100, the gas molecules are affected by the surface adhesion force and slow down, forming a large velocity gradient. At corners, this velocity gradient will aggravate the instability of the gas flow, making the airflow more susceptible to interference and separation.

[0051] In a centrifugal fan according to an embodiment of the present invention, a smooth transition is formed between the end of the flow channel 150 and the inner wall of the volute 100 corresponding to the outlet of the air outlet 140. This prevents abrupt changes in the flow velocity and pressure of the gas on the inner wall surface of the air outlet 140 due to a non-smooth transition, thereby reducing the occurrence of flow separation, effectively reducing the noise generated when the gas flows out of the air outlet 140, and reducing the instability of the air outlet 140.

[0052] In this embodiment, the circumferential cross-section of the flow channel 150 along the axis of the air inlet 190 and at different azimuth angles is substantially rectangular, while the outlet of the air outlet portion 140 is circular. The inner wall of the air outlet portion 140 achieves a smooth transition from the substantially rectangular to the circular shape. Of course, the circumferential cross-section of the flow channel 150 and the shape of the outlet of the air outlet portion 140 can be adjusted according to actual use requirements. For example, the circumferential cross-section of the flow channel 150 is rectangular, while the outlet of the air outlet portion 140 is substantially rectangular, so as to achieve a smooth transition from rectangular to substantially rectangular.

[0053] According to one embodiment of the present invention, Figure 5 、 Figure 6 and Figure 8 As shown, by setting the outer periphery of the outlet of the air outlet portion 140 to be a smooth curve, there are no sudden changes in corners and geometric shapes at the outlet position, which avoids the rapid changes in gas flow rate and pressure caused by corners, thereby reducing the occurrence of flow separation, effectively reducing the noise generated when the gas flows out of the air outlet portion 140, and reducing gas flow fluctuations to achieve a uniform air outlet effect of the air outlet portion 140.

[0054] According to one embodiment of the present invention, the centrifugal fan further includes a check valve 300 , which is provided with an air outlet channel 310 , the inlet of which is connected to the outlet of the air outlet portion 140 , and the cross-sectional area of ​​the air outlet channel 310 gradually increases along the airflow direction.

[0055] Check valve 300 effectively prevents reverse airflow, preventing excessive energy loss. Preventing reverse airflow can cause vibration, shock, and noise within the centrifugal fan, potentially damaging the equipment. Maintaining consistent airflow direction within the centrifugal fan system ensures stable pressure during system shutdown, thereby improving overall system efficiency and performance.

[0056] By gradually increasing the cross-sectional area of ​​the air outlet passage 310, eddy currents and vibrations in the air outlet passage 310 are prevented, thereby preventing noise and damage. Furthermore, the velocity of the air flowing out of the outlet of the air outlet portion 140 is further reduced, thereby reducing the pressure loss of the air and thereby improving the efficiency of the centrifugal fan.

[0057] In this embodiment, combined with Figure 1 As shown, the height dimension H2 of the check valve 300 should be less than 500 mm to meet the installation requirements of the centrifugal fan in the range hood. Of course, based on different installation spaces, the height dimension of the check valve 300 can be adaptively adjusted.

[0058] According to one embodiment of the present invention, Figure 7 and Figure 8 As shown, at least one of the outlet of the air outlet 140 and the outlet of the check valve 300 is circular. The circular outlet design (referring to the outlet of the air outlet 140 and the outlet of the check valve 300) ensures more uniform gas flow, reduces the velocity gradient and vortex intensity of the gas flow, and thus reduces the noise generated during gas flow. Furthermore, the circular shape of the outlet of the check valve 300 effectively adapts to the shape of the external pipeline, reducing production costs and installation difficulty.

[0059] Of course, the outlet of the air outlet 140 and the outlet of the check valve 300 are not limited to circular shapes, and other shapes can be selected according to actual needs, such as elliptical, quasi-circular, quasi-rectangular, a combination of semi-circular and semi-elliptical shapes, etc. Of course, the outlet shape of the air outlet 140 can also be different from the outlet shape of the check valve 300, such as the outlet of the air outlet 140 being quasi-rectangular while the outlet of the check valve 300 being circular. Of course, the inner wall of the check valve 300 can also be configured to smoothly transition from the outlet of the air outlet 140 to the outlet of the check valve 300 to reduce the noise generated by the gas flowing within the check valve 300.

[0060] According to one embodiment of the present invention, Figure 7 and Figure 8 As shown, when both the outlet of the air outlet portion 140 and the outlet of the check valve 300 are circular, the outlet diameter of the air outlet channel 310 is less than or equal to twice the inlet diameter of the air outlet channel 310. Avoiding a large diameter difference between the inlet and outlet of the air outlet channel 310 can lead to large speed changes during gas flow, causing gas fluctuations and vortexes, leading to increased noise in the centrifugal fan, energy loss, and vibration of the check valve 300. A large difference in inlet and outlet diameters can also create greater resistance to gas flow, resulting in greater pressure loss, increasing the operating cost of the centrifugal fan and reducing efficiency. It can also easily lead to uneven force inside the check valve 300, affecting the normal opening and closing of the check valve 300, and causing damage or failure of the centrifugal fan.

[0061] According to one embodiment of the present invention, Figures 4 to 6 As shown, a volute tongue 500 is provided on one side of the air outlet 140. The volute tongue 500 is recessed toward the side away from the air outlet 140 to form a recessed portion 510. The volute tongue 500 is adapted to divert gas flowing out of the flow passage 150. The volute tongue 500 allows some gas to be discharged from the volute 100 along the air outlet 140, while the remaining gas circulates into the flow passage 150 to balance the static pressure within the flow passage 150.

[0062] The recessed portion 510 effectively increases the area of ​​the outlet 140 inlet, reducing the gas flow rate and weakening the impact of the gas on the volute 500 as it flows through the outlet 140 inlet. Furthermore, the concave shape of the volute 500 creates a phase difference in the incoming flow impacting the volute 500 along the width of the volute 500 along the axis of the air inlet 190, effectively dispersing the coupling between aerodynamic noises of different frequencies. This effectively suppresses the local high-pressure area near the volute 500, reduces the axial pressure gradient of the air inlet 190, weakens the low-order unsteady flow near the wall of the volute 100, reduces the turbulent kinetic energy near the wall, improves the uniformity of the gas flow, and thus reduces noise.

[0063] In this embodiment, recessed portion 510 is configured to fit the outlet inlet in a circular notch shape, forming a circular whole with the inner wall of the outlet inlet. This improves the stability of airflow entering the outlet, reduces the velocity gradient and vortex intensity of the gas flow, and thus reduces noise generated during gas flow. Of course, recessed portion 510 can also be configured as a rectangular notch, a triangular notch, or other shape suitable for increasing the area of ​​the outlet inlet.

[0064] In one embodiment, the volute tongue 500 is a separate component that is detachably connected to the housing 170. This allows for customization based on specific needs and design requirements, providing greater flexibility. Furthermore, only damaged volute tongues 500 need to be repaired or replaced, eliminating the need to replace the entire volute 100. This reduces maintenance costs and time.

[0065] According to one embodiment of the present invention, Figure 9 As shown, the recessed portion 510 comprises a smooth curved surface, forming a smooth structure with the inlet of the air outlet portion 140. This ensures that the size of the flow path of the gas flowing at the inlet of the air outlet portion 140 changes gradually, avoiding sudden changes in the gas flow rate and pressure, thereby reducing the occurrence of flow separation and effectively reducing the noise generated during the operation of the centrifugal fan.

[0066] According to one embodiment of the present invention, Figures 4 to 6 As shown, the outlet of the air outlet portion 140 has an axis, and the air inlet 190 has a center line parallel to the axis. Figure 6As shown in FIG, the dotted line at the center of the outlet of the air outlet 140 is its axis, the dotted line on the right side parallel to this axis is the centerline of the air inlet 190, and the volute tongue 500 is located on the side of the centerline close to the air outlet 140. This allows the airflow direction of the air outlet 140 to extend radially outward while reducing the obstruction of the air outlet 140 and the volute tongue 500 to the gas flow, allowing the gas to be more stably separated and returned to the reflow channel 150, reducing gas rotation and turbulence, and improving the aerodynamic performance of the fan. It can also better shield the circumferential blades of the impeller inside the volute 100, preventing large particles of impurities or foreign matter from directly hitting the impeller, reducing damage and wear to the impeller, and extending the service life of the equipment.

[0067] According to one embodiment of the present invention, Figure 7 and Figure 8 As shown, the volute 100 also includes a first connecting plate 160, which is arranged at the end of the outlet of the air outlet portion 140 and extends radially along the air outlet portion 140; corresponding to the first connecting plate 160, a second connecting plate 320 is arranged at one end of the inlet of the check valve 300.

[0068] The first connecting plate 160 and the second connecting plate 320 position the connection portion outside the flow channel 150, effectively ensuring a smooth transition between the flow channel 150 of the volute 100, the inner wall of the air outlet 140, and the air outlet passage 310 of the check valve 300. This effectively prevents sudden changes in the path size of the gas flowing within the centrifugal fan, thereby avoiding sudden changes in gas flow rate and pressure. This reduces flow separation and effectively reduces noise generated during operation of the centrifugal fan. Furthermore, the first connecting plate 160 and the second connecting plate 320 facilitate direct installation in external equipment (such as the housing of a range hood), reducing the difficulty of centrifugal fan installation.

[0069] In this embodiment, the outer peripheries of the first connecting plate 160 and the second connecting plate 320 are both rectangular; of course, the outer peripheries of the first connecting plate 160 and the second connecting plate 320 can be adaptively adjusted according to the shape and position of the actual installation space.

[0070] Combine Figures 1 to 3 As shown, according to one embodiment of the present invention, the volute 100 includes a volute-shaped side arc plate portion 110 and a cover plate portion 120 located on both sides of the side arc plate portion 110, at least one of the cover plate portions 120 on both sides is provided with an air inlet 190, and the air inlet 190 is suitable for connecting the flow channel 150 with the outside world; an arc-shaped transition portion 130 is provided at the connection between the side arc plate portion 110 and the cover plate portion 120.

[0071] By providing the transition portion 130, when the gas flows through the surface of the volute 100 or inside the flow channel 150, since there is no position where the geometric shape changes suddenly between the cover plate portion 120 and the side arc plate portion 110 of the volute 100, the size of the gas flow path changes gradually, thereby avoiding the rapid changes in gas flow rate and pressure caused by corners, thereby reducing the occurrence of flow separation and effectively reducing the noise generated during the operation of the centrifugal fan.

[0072] In this embodiment, an air inlet is respectively provided on the cover plate portion 120 on both sides of the side arc plate portion 110; of course, the number and position of the air inlets can be adjusted according to actual needs, such as only providing an air inlet on one cover plate portion 120 or providing multiple air inlets on one cover plate portion 120.

[0073] In this embodiment, combined with Figure 1 and Figure 2 As shown, the width W of the volute 100 should be less than 550 mm, and the height H1 of the volute 100 should be less than 500 mm, meeting the installation requirements of the centrifugal fan in the range hood. Of course, the height and width of the volute 100 can be adaptively adjusted based on different installation spaces.

[0074] In one embodiment, combined Figure 2 As shown, the transition portion 130 includes a first transition surface 131 , which is provided on the outer surface of the volute 100 .

[0075] By providing a first transition surface 131 on the outer surface of the volute 100, there is no position on the outer surface of the volute 100 where the geometric shape suddenly changes, so the size of the gas flow path changes gradually, thereby avoiding sudden changes in the gas flow rate and pressure, thereby reducing the occurrence of flow separation, and effectively reducing the noise generated by the gas flowing on the outer surface of the volute 100 during the operation of the centrifugal fan.

[0076] In one embodiment, combined Figure 2 As shown, the transition portion 130 includes a second transition surface 132, which is provided on the inner surface of the volute 100. The second transition surface 132 eliminates corners in the flow channel 150, optimizes the flow of gas in the volute 100, effectively avoids the generation of vortices in the flow channel 150, and thus reduces the noise generated in the flow channel 150 of the volute 100.

[0077] In one embodiment, the transition portion 130 of the volute 100 may have both a first transition surface 131 and a second transition surface 132, thereby reducing the noise generated by the gas flowing through the outer and inner surfaces of the volute 100 and effectively improving the overall noise reduction effect of the centrifugal fan.

[0078] According to one embodiment of the present invention, Figures 1 to 3As shown, along the spiral air outlet direction of the volute 100 , the curvature radius of the first transition surface 131 or the second transition surface 132 gradually increases.

[0079] Taking the curvature radius of the second transition surface 132 as an example, along the spiral outlet direction of the volute 100, the gas within the volute 100 sequentially passes through points A1, B1, A2, and B2. That is, the curvature radius R1 corresponding to A1, the curvature radius R2 corresponding to B1, the curvature radius R3 corresponding to A2, and the curvature radius R4 corresponding to B2 increase in that order. Of course, the curvature radius of the first transition surface 131 is similar.

[0080] In one embodiment, in order to achieve the pressurization and deceleration effect of the centrifugal fan on the gas, the cross-sectional area of ​​the flow channel 150 gradually increases along the spiral exhaust direction. In order to adapt to the changing trend of the flow channel 150, the curvature radius of the second transition surface 132 is correspondingly increased to prevent the gas in the middle position of the flow from deviating toward the second transition surface 132 due to the expansion of the cross-sectional area of ​​the flow channel 150, while the gas flow direction and size on the surface of the second transition surface 132 remain unchanged, and then the collision between the gases forms more vortices, generating noise.

[0081] In one embodiment, the curvature radius of the first transition surface 131 is gradually increased to adapt to the connection between the side arc plate portion 110 and the cover plate portion 120 that gradually deviates toward the outside of the axis of the air inlet 190, thereby effectively improving the structural strength between the two.

[0082] According to one embodiment of the present invention, Figure 2 As shown, the radius of curvature of the first transition surface 131 or the second transition surface 132 is less than or equal to half the width of the side arc plate portion 110. Avoid the radius of curvature of the first transition surface 131 or the second transition surface 132 exceeding half the width of the side arc plate portion 110, which would otherwise form a bulge in the middle of the side arc plate portion 110. The formation of the bulge would affect the geometric shape of the outer surface (corresponding to the first transition surface 131) or the inner surface (corresponding to the second transition surface 132) of the volute 100, causing a sudden change in the flow rate and pressure of the gas, increasing the occurrence of flow separation, and causing more noise during the operation of the centrifugal fan.

[0083] According to one embodiment of the present invention, Figure 2As shown, a transition portion 130 with a uniform wall thickness is formed between the first transition surface 131 and the second transition surface 132. This makes the manufacturing process of the volute 100 more convenient and efficient. For example, when forging is used, the pressing process for the position of the transition portion 130 is the same as that for the cover plate portion 120 or the side arc plate portion 110, reducing the difficulty of forging. Of course, the curvature radius of the first transition surface 131 and the curvature radius of the second transition surface 132 can also be set to be unequal, so as to form a transition portion 130 with a thickness different from that of the cover plate portion 120 or the side arc plate portion 110, thereby strengthening the thickness of the transition portion 130 and improving the structural strength of the volute 100.

[0084] In one embodiment, the side arc plate portion 110 and the cover plate portion 120 are integrally formed, which can eliminate the connection between multiple parts and avoid the existence of weaknesses and looseness in the volute 100 due to welding or bolting. In this way, the overall strength and stability of the volute 100 are improved. The risk of leakage at the joints and seals can be reduced, thereby reducing the loss of airflow. Especially under high-pressure and high-speed airflow conditions, the integral molding of the volute 100 can ensure the smooth and stable airflow and avoid leakage and disturbance of the airflow. It also reduces processing procedures and manual intervention, and improves production efficiency and production quality. At the same time, since the volute 100 does not have connections between multiple parts, the time and cost required for maintenance and replacement can also be reduced.

[0085] In another embodiment, combined Figure 4 As shown, the volute 100 comprises at least two joined shell sections 170. The size, number, and shape of the shell sections 170 can be customized according to specific needs and design requirements, providing high flexibility. Furthermore, only damaged shell sections 170 need to be repaired or replaced, rather than the entire volute 100. This reduces maintenance costs and time.

[0086] In this embodiment, the volute 100 includes two shell portions 170, and the joint gap between the two shell portions 170 is located in the middle of the side arc plate portion 110. Of course, the volute 100 can also include more shell portions 170 to adapt to different installation requirements of the volute 100 in different situations. For example, the cover plate portion 120 or the side arc plate portion 110 can be separately formed into different shell portions 170 for splicing, and the position of the joint gap between the multiple shell portions 170 can be changed accordingly.

[0087] According to one embodiment of the present invention, Figure 1 and Figure 2 As shown, the centrifugal fan also includes an air guide ring 400, which is provided with a first air inlet channel 410. The first air inlet channel 410 connects the air inlet 190 with the outside world. The cross-sectional area of ​​the first air inlet channel 410 gradually decreases along the direction from the outside world to the air inlet 190.

[0088] The setting of the first air inlet channel 410 ensures that the flow path of the gas entering the air inlet 190 from the outer surface of the volute 100 gradually shrinks without sudden changes in the size of the path, thereby avoiding sudden changes in the flow rate and pressure of the gas, thereby reducing the occurrence of flow separation and effectively reducing the noise generated during the operation of the centrifugal fan.

[0089] In this embodiment, an air guide ring 400 is provided for the main air inlet 190 of the two air inlets 190 of the centrifugal fan. Of course, air guide rings 400 can also be provided on all air inlets 190 to improve the noise reduction effect of the centrifugal fan.

[0090] Experimental results show that the centrifugal fan according to an embodiment of the present invention, through the design of a cambered volute 100 with a transition portion 130 and a smooth transition design at the outlet of the air outlet 140, can effectively improve flow separation inside the fan and at the outlet, significantly reduce the presence of separation vortices, and improve the flow uniformity of the gas at the outlet of the volute 100. Compared with a conventional volute 100 with a rectangular cross-section, the centrifugal fan volute 100 of the present application can reduce noise by 2dB at the same air volume.

[0091] A range hood according to an embodiment of the second aspect of the present invention includes a housing and a centrifugal fan as described in the above embodiment, wherein the centrifugal fan is placed in the housing.

[0092] The beneficial effects of the range hood according to the embodiment of the present invention are the same as the effective effects of the centrifugal fan in the embodiment of the first aspect of the present invention, and will not be repeated here.

[0093] Finally, it should be noted that the above embodiments are intended to illustrate the present invention only and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the embodiments, it should be understood by those skilled in the art that various combinations, modifications, or equivalent substitutions of the technical solutions of the present invention do not depart from the spirit and scope of the technical solutions of the present invention and are intended to be encompassed by the claims of the present invention.

Claims

1. A centrifugal fan, characterized in that: include: A volute, wherein the volute is provided with a flow channel, and the flow channel extends along the spiral air outlet direction of the volute; The volute is provided with an air outlet portion extending radially outward, the inlet of the air outlet portion is connected to the end of the flow channel, and the inner wall of the volute corresponding to the end of the flow channel and the outlet of the air outlet portion is smoothly transitioned.

2. The centrifugal fan according to claim 1, characterized in that: The outer periphery of the outlet of the air outlet portion is a smooth curve.

3. The centrifugal fan according to claim 1, characterized in that: The centrifugal fan further includes a check valve, which is provided with an air outlet channel. The inlet of the air outlet channel is connected to the outlet of the air outlet portion, and the cross-sectional area of ​​the air outlet channel gradually increases along the airflow direction.

4. The centrifugal fan according to claim 3, characterized in that: At least one of the outlet of the air outlet portion and the outlet of the check valve is circular.

5. The centrifugal fan according to any one of claims 1 to 4, characterized in that: A volute tongue is provided on one side of the air outlet portion. The volute tongue is recessed toward the side away from the air outlet portion to form a recessed portion. The volute tongue is suitable for diverting the gas flowing out of the flow channel.

6. The centrifugal fan according to claim 5, characterized in that: The recessed portion includes a smooth curved surface, and the recessed portion and the inlet of the air outlet portion form a smooth structure.

7. The centrifugal fan according to claim 5, characterized in that: The outlet of the air outlet has an axis, the air inlet has a center line parallel to the axis, and the volute tongue is located on a side of the center line close to the air outlet.

8. The centrifugal fan according to claim 5, characterized in that: The volute comprises at least two shell parts spliced ​​together, and the volute tongue is detachably connected to the shell parts.

9. The centrifugal fan according to any one of claims 3 to 4, characterized in that: The volute further includes a first connecting plate, which is provided at the end of the outlet of the air outlet portion and extends in the radial direction of the air outlet portion; Corresponding to the first connecting plate, a second connecting plate is provided at one end of the inlet of the check valve.

10. A range hood, characterized in that: include: Box; The centrifugal fan according to any one of claims 1 to 9, wherein the centrifugal fan is placed in the casing.

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