CN220286038U - Range hood, centrifugal fan and blades thereof - Google Patents

Abstract

The application relates to a range hood, centrifugal fan and blade thereof, the blade is equipped with first side edge, and first side edge is equipped with the line segment of making an uproar falls, and the line segment of making an uproar falls is arranged in the upper end and/or the lower extreme of blade, and the interval of the central axis of line segment of making an uproar falls and centrifugal fan is the trend of reducing along the air inlet direction, is equipped with a plurality of sawtooth that arrange in proper order on the line segment of making an uproar falls. The first side edges of the upper end and/or the lower end of the blade are provided with chamfer angles, so that on one hand, an avoidance space can be formed, the inner diameter of the air inlet ring is designed to be relatively larger, and the air inflow is more sufficient; on the other hand, compared with a vertical side parallel to the central axis, the length of the noise reduction line segment is longer, so that the number of the arranged saw teeth is more, and wind breaking is facilitated; in addition, during air inlet, each sawtooth on the noise reduction line segment contacts with the air at different times, so that the noise with different frequencies is generated, the air noise is lower, and the pneumatic noise reduction effect is better.

Description

Range hood, centrifugal fan and blades thereof

Technical Field

The application relates to the technical field of range hoods, in particular to a range hood, a centrifugal fan and blades thereof.

Background

The range hood is a kitchen appliance for purifying kitchen environment, is usually arranged above a kitchen range, and can rapidly pump away the oil smoke generated during cooking. The range hood comprises a frame and a fan assembly positioned in the frame. The fan assembly comprises a volute, an impeller and a centrifugal fan driving the impeller to rotate. When the range hood sucks oil smoke, the motor drives the impeller to rotate, under the action of centrifugal force, negative pressure is generated at the center of the volute, the smoke is sucked from the air inlet, and the smoke is accelerated and then is output outwards. Thus, cooking fume can enter the volute under the suction of the negative pressure area, and the indoor air can be purified.

The blade edges of the impeller in the related art are generally flat, so that the impeller is easy to be impacted by periodical high-speed airflow when rotating at a high speed, and larger aerodynamic noise is generated.

Disclosure of Invention

The first technical problem that this application solved is to provide a centrifugal fan's blade, and it can reduce pneumatic noise effectively.

The second technical problem that this application solved is to provide a centrifugal fan, and it can reduce pneumatic noise effectively.

The third technical problem that this application solved is to provide a range hood, and it can reduce pneumatic noise effectively.

The first technical problem is solved by the following technical scheme:

the utility model provides a centrifugal fan's blade, the blade is equipped with and is close to centrifugal fan's central axis's first side edge, first side edge is equipped with the line segment of making an uproar falls, the line segment of making an uproar falls arrange in the upper end and/or the lower extreme of blade, the line segment of making an uproar falls with centrifugal fan's central axis's interval is the trend of reducing in the edge air inlet direction, be equipped with a plurality of sawtooth that arrange in proper order on the line segment of making an uproar falls.

The blade of centrifugal fan, the produced beneficial effect of comparing with the background art:

according to the blade of the centrifugal fan, as the noise reduction line segments are arranged at the first side edges, the noise reduction line segments are arranged at the upper end and/or the lower end of the blade, the distance between the noise reduction line segments and the central axis of the centrifugal fan is in a decreasing trend along the air inlet direction, namely, the first side edges at the upper end and/or the lower end of the blade are provided with the chamfer, so that on one hand, an avoidance space can be formed, the inner diameter of the air inlet ring is designed to be relatively larger, and the air inflow is more sufficient; on the other hand, compared with a vertical side parallel to the central axis, the length of the noise reduction line segment is longer, so that the number of the arranged saw teeth is more, and wind breaking is facilitated; in addition, when the air current strikes first side edge, each sawtooth on the noise reduction line segment can avoid the air current to strike blade first side edge simultaneously to total noise frequency that produces when the scattered air current strikes the blade, pneumatic noise reduction effect is better.

In one embodiment, the middle part of the first side edge is provided with a straight line edge.

In one embodiment, the upper end and/or the lower end of the blade is provided with a chamfer, and the contour of the chamfer comprises the noise reduction line segment.

In one embodiment, the chamfer has an arc-shaped profile or a hypotenuse disposed at an angle to the central axis.

In one embodiment, the blade is further provided with a second side edge opposite to the first side edge and far away from the central axis of the centrifugal fan, and when the upper end of the blade is provided with a chamfer, a first endpoint and a second endpoint are formed on the chamfer contour of the upper end of the blade, and the first endpoint is located above the second endpoint; the distance between the first side edge and the second side edge is set as D, and the vertical distance between the first end point and the extension line of the straight line edge is set as D1, wherein D1/D is less than or equal to 0.5; the distance between the top edge of the blade and the bottom edge of the blade is set to be H, and the vertical distance between the second end point and the top edge of the blade is set to be H1, wherein H1/H is less than or equal to 0.5.

In one embodiment, the blade is further provided with a second side edge opposite to the first side edge and far away from the central axis of the centrifugal fan, and when the lower end of the blade is provided with a chamfer, a chamfer contour of the lower end of the blade is formed with a third end point and a fourth end point, and the third end point is positioned above the fourth end point; the distance between the first side edge and the second side edge of the blade is set as D, and the distance between the vertical distance between the fourth end point and the extension line of the straight line edge is set as D2, wherein D2/D is less than or equal to 0.5; the distance between the top edge of the blade and the bottom edge of the blade is H, and the vertical distance between the third end point and the bottom edge of the blade is H2, wherein H2/H is less than or equal to 0.4.

In one embodiment, the serrations are one or more of circular arc, pointed, wavy, fang Bozhuang, S-shaped, and W-shaped.

In one embodiment, when the saw teeth are in an arc shape, the saw teeth form arc-shaped concave parts, the depth of the arc-shaped concave parts is set to be a1, the vertex distance between every two adjacent saw teeth is set to be a2, wherein a1 is more than or equal to 3mm and less than or equal to 15mm, and a2 is more than or equal to 1mm and less than or equal to 5mm.

The second technical problem is solved by the following technical scheme:

a centrifugal fan, the centrifugal fan comprising: the impeller comprises a front disc, a rear disc and blades of the centrifugal fan, wherein the blades are arranged between the front disc and the rear disc.

The centrifugal fan that this application described, compared with the prior art produced beneficial effect:

according to the centrifugal fan, as the noise reduction line segments are arranged at the first side edges and are arranged at the upper ends and/or the lower ends of the blades, the distance between the noise reduction line segments and the central axis of the centrifugal fan is reduced in the air inlet direction, namely, the first side edges at the upper ends and/or the lower ends of the blades are provided with the chamfer angles, so that on one hand, an avoidance space can be formed, the inner diameter of the air inlet ring is designed to be relatively larger, and the air inflow is more sufficient; on the other hand, compared with a vertical side parallel to the central axis, the length of the noise reduction line segment is longer, so that the number of the arranged saw teeth is more, and wind breaking is facilitated; in addition, when the air current strikes first side edge, each sawtooth on the noise reduction line segment can avoid the air current to strike blade first side edge simultaneously to total noise frequency that produces when the scattered air current strikes the blade, pneumatic noise reduction effect is better.

The third technical problem is solved by the following technical scheme:

a range hood comprises the centrifugal fan.

The range hood provided by the application has the beneficial effects compared with the background art:

according to the range hood, as the noise reduction line segments are arranged at the upper end and/or the lower end of the blades, the distance between the noise reduction line segments and the central axis of the centrifugal fan is reduced along the air inlet direction, namely, the first side edges of the upper end and/or the lower end of the blades are provided with the chamfer angles, on one hand, an avoidance space can be formed, the inner diameter of the air inlet ring is designed to be relatively larger, and the air inflow is more sufficient; on the other hand, compared with a vertical side parallel to the central axis, the length of the noise reduction line segment is longer, so that the number of the arranged saw teeth is more, and wind breaking is facilitated; in addition, when the air current strikes first side edge, each sawtooth on the noise reduction line segment can avoid the air current to strike first side edge simultaneously to the total noise frequency that produces when the scattered air current strikes the blade, pneumatic noise reduction effect is better.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application, illustrate and explain the application and are not to be construed as limiting the application.

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a sectional view of a centrifugal fan according to an embodiment of the present application.

Fig. 2 is a sectional view of the impeller in the structure shown in fig. 1.

Fig. 3 is a front perspective view of the blade in the configuration shown in fig. 2.

Fig. 4 is an enlarged structural view of an embodiment at a of fig. 3.

Fig. 5 is an enlarged structural view of another embodiment of fig. 3 at a.

Fig. 6 is an enlarged structural view of still another embodiment at a of fig. 3.

Reference numerals:

10. a blade; 11. a first side edge; 111. a noise reduction line segment; 1111. a first noise reduction line segment; 1112. a second noise reduction line segment; 112. saw teeth; 1121. a concave portion; 1122. a vertex; 113. a straight line edge; 12. a second side edge; 13. an upper end; 131. a first chamfer; 1311. a first endpoint; 1312. a second endpoint; 132. a top edge; 14. a lower end; 141. a second chamfer; 1411. a third endpoint; 1412. a fourth endpoint; 142. a bottom edge; 20. a volute; 30. an impeller; 31. a front plate; 32. a rear tray; 33. a middle plate; 34. an air inlet ring; 40. and a motor.

Detailed Description

In order to make the above objects, features and advantages of the present application more comprehensible, embodiments accompanied with figures are described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. This application is, however, susceptible of embodiment in many other forms than those described herein and similar modifications can be made by those skilled in the art without departing from the spirit of the application, and therefore the application is not to be limited to the specific embodiments disclosed below.

Referring to fig. 1 to 3, fig. 1 shows a sectional structural view of a centrifugal fan according to an embodiment of the present application. Fig. 2 is a sectional view of the impeller 30 in the structure shown in fig. 1, and does not include the motor 40 and the scroll casing 20 provided inside the impeller 30, as compared to fig. 1. Fig. 3 shows a schematic view of the front projection of the blade in the configuration shown in fig. 2. According to the blade of the centrifugal fan, the blade 10 is provided with the first side edge 11 close to the central axis of the centrifugal fan, and the first side edge 11 is provided with the noise reduction line segment 111. The noise reduction line segment 111 is arranged at the upper end 13 and/or the lower end 14 of the blade 10, the distance S between the noise reduction line segment 111 and the central axis O of the centrifugal fan is in a decreasing trend along the air inlet direction f, and a plurality of sawteeth 112 are sequentially arranged on the noise reduction line segment 111.

The blade 10 is further provided with a second side edge 12. The second side edge 12 and the first side edge 11 are respectively disposed on two opposite sides of the blade 10. The distance between the first side edge 11 and the central axis of the centrifugal fan is smaller than the distance between the windward side of the outer edge and the central axis of the centrifugal fan.

The upper end 13 of the blade 10 refers to the end of the blade 10 connected to the front plate 31, and the lower end 14 of the blade 10 refers to the end of the blade 10 connected to the rear plate 32.

In the above-mentioned centrifugal fan blade, since the first side edge 11 is provided with the noise-reducing line segment 111, the noise-reducing line segment 111 is disposed at the upper end 13 and/or the lower end 14 of the blade 10, and the space S between the noise-reducing line segment 111 and the central axis of the centrifugal fan is in a decreasing trend along the air inlet direction f, that is, the first side edge 11 of the upper end 13 and/or the lower end 14 of the blade 10 is provided with a chamfer, so that on one hand, an avoidance space can be formed, the inner diameter of the air inlet ring 34 is designed to be relatively larger, and the air inflow is more sufficient; on the other hand, the length of the noise reduction line segment 111 is longer than that of a vertical side parallel to the central axis, so that the number of the arranged saw teeth 112 is larger, and wind breaking is facilitated; in addition, when the airflow impacts the first side edge 11, each sawtooth 112 on the noise reduction line segment 111 can avoid the airflow to impact the first side edge 11 of the blade at the same time, so that the total noise frequency generated when the airflow impacts the blade is dispersed, and the pneumatic noise reduction effect is better.

When the noise reduction line segments 111 are two and are respectively located at the upper end 13 and the lower end 14 of the blade 10, wind enters the volute 20 from the upper end 13 of the blade 10, and the noise reduction line segments 111 at the upper end 13 of the blade 10 are in contact with the wind to perform a wind breaking function and reduce pneumatic noise; similarly, during the process that wind enters the volute 20 from the lower end 14 of the blade 10, the noise reduction line segment 111 of the lower end 14 of the blade 10 contacts with the wind, so as to play a role in breaking the wind and reduce the aerodynamic noise.

Referring to fig. 3, in one embodiment, a middle portion of the first side edge 11 is provided as a straight edge 113. In this way, the middle part of the first side edge 11 is not provided with the saw teeth 112, so that the blade can be conveniently installed in the installation hole formed in the middle of the middle disc 33, and the assembly clamping fault caused by the saw teeth 112 designed in the middle part of the first side edge 11 is avoided.

Of course, as an alternative, a plurality of serrations 112 may be provided in the middle of the first side edge 11. Specifically, the first side edge 11 is provided with serrations 112 from one end to the other end.

Referring to fig. 1-3, in one embodiment, the upper end 13 and/or the lower end 14 of the blade 10 is provided with a chamfer. The chamfered profile includes a noise reduction line segment 111. In this way, the whole form of the noise reduction line segment 111 is a chamfer disposed at the upper end 13 and/or the lower end 14 of the blade 10, so that the plurality of saw teeth 112 for wind breaking noise reduction on the noise reduction line segment 111 are sequentially disposed along the chamfer profile, and the wind breaking noise reduction effect can be improved.

In one embodiment, the upper end 13 of the blade 10 is provided with a first chamfer 131. The contour of the first chamfer 131 includes a first noise reduction line segment 1111, i.e., the first noise reduction line segment 1111 is disposed entirely along the contour of the first chamfer 131.

In another embodiment, the lower end 14 of the blade 10 is provided with a second chamfer 141. The profile of the second chamfer 141 includes a second noise reduction line segment 1112, i.e., the second noise reduction line segment 1112 is disposed entirely along the profile of the second chamfer 141.

In a further embodiment, the upper end 13 of the blade 10 is provided with a first chamfer 131. The contour of the first chamfer 131 includes a first noise reduction line segment 1111, i.e., the first noise reduction line segment 1111 is disposed entirely along the contour of the first chamfer 131. Further, the lower end 14 of the blade 10 is provided with a second chamfer 141. The profile of the second chamfer 141 includes a second noise reduction line segment 1112, i.e., the second noise reduction line segment 1112 is disposed entirely along the profile of the second chamfer 141. The shape of each sawtooth 112 set on the first noise reduction line segment 1111 may be completely the same as or completely different from each sawtooth 112 set on the second noise reduction line segment 1112, or may be partially the same, which may be specifically flexibly adjusted and set according to actual requirements.

In one embodiment, the chamfer is contoured in an arc or a hypotenuse disposed at an angle to the central axis. Thus, the chamfer can be either an arc chamfer or a hypotenuse chamfer.

Referring to fig. 1-3, in one embodiment, when the upper end 13 of the blade 10 is provided with a chamfer, the chamfer profile of the upper end 13 of the blade 10 is formed with a first end point 1311 and a second end point 1312. The first end point 1311 is located above the second end point 1312. Wherein, the distance between the first side edge 11 and the second side edge 12 of the blade 10 is set as D, and the vertical distance between the first end point 1311 and the extension line of the straight line edge 113 of the first side edge 11 is set as D1, and D1/D is less than or equal to 0.5. The ratio of D1/D determines the length of the fastening joint between the top edge 132 of the upper end 13 of the blade 10 and the front plate 31, and if the length is higher than 0.5, the length of the joint overlapping between the top edge 132 of the upper end 13 of the blade 10 and the front plate 31 is insufficient, so that the blade 10 is not fastened on the front plate 31, and the upper ends 13 of the subsequent blades are easy to loosen.

In addition, the distance between the top edge 132 of the blade 10 and the bottom edge 142 of the blade 10 is set to H, and the vertical distance between the second end 1312 and the top edge 132 of the blade 10 is set to H1, wherein H1/H is equal to or less than 0.5. Therefore, the ratio of H1/H is set appropriately, so that the inclination angle of the noise reduction line segment 111 of the lower end 14 of the blade 10 is large enough, and the wind breaking noise reduction effect is good. If the ratio of H1/H is greater than 0.5, the inclination angle of the noise reduction line segment 111 at the lower end 14 of the blade 10 is insufficient, which affects the reduction of the opening diameter of the air inlet ring 34 and the air volume.

Referring to fig. 1-3, in one embodiment, when the lower end 14 of the blade 10 is provided with a chamfer, the chamfer profile of the lower end 14 of the blade 10 is formed with a third end 1411 and a fourth end 1412. The third point 1411 is located above the fourth point 1412. Wherein, the distance between the first side edge 11 and the second side edge 12 of the blade 10 is set as D, and the vertical distance between the fourth end 1412 and the extension line of the straight line edge 113 of the first side edge 11 is set as D2, and D2/D is less than or equal to 0.5. The ratio of D2/D determines the length of the location where the bottom edge 142 of the blade 10 is fastened to the rear plate 32. If the length is greater than 0.5, the length of the location where the bottom edge 142 of the blade 10 is overlapped with the rear plate 32 is insufficient, so that the blade 10 is not fastened to the rear plate 32, and the lower end 14 of the subsequent blade is easy to loosen.

Further, the distance between the top edge 132 of the blade 10 and the bottom edge 142 of the blade 10 is H, and the vertical distance between the third end 1411 and the bottom edge 142 of the blade 10 is H2, and H2/H is 0.4 or less. Therefore, the proportion of H2/H is set to be proper, so that the front and back air inlet distribution of the fan is uniform, and the air inlet efficiency is not affected.

The ratio of H2/H is set correspondingly with the position of the disk 33 in the blade, and when the ratio of H2/H is greater than 0.4, the front and rear intake air of the fan is unevenly distributed, which affects the intake efficiency.

Referring to fig. 3-6, fig. 4-6 show three different enlarged schematic views of fig. 3 at a, respectively. In one embodiment, serrations 112 include, but are not limited to, one or more of circular arc-shaped (as shown in fig. 4), pointed-shaped (as shown in fig. 5), wavy (as shown in fig. 6), square wave-shaped, S-shaped, and W-shaped. However, the sharp angle shape shown in fig. 5 is more sharp than the arc shape shown in fig. 4, and the wind breaking effect is better.

Referring to FIG. 4, in one embodiment, when the saw teeth 112 are arc-shaped, the saw teeth 112 form arc-shaped concave portions 1121, the depth of the arc-shaped concave portions 1121 is set to be a1, the pitch of the peaks 1122 of two adjacent saw teeth 112 is set to be a2, wherein a1 is equal to or less than 3mm and 15mm, a2 is equal to or less than 1mm and 5mm. Therefore, the sizes of the a1 and the a2 are respectively reasonable, and the wind breaking and noise reducing effects are better when the processing and manufacturing are convenient.

Of course, in some alternative solutions, a1 may also be set to any value smaller than 3mm and larger than 15mm, and a2 may also be set to any value smaller than 1mm and larger than 5mm, which may be specifically and flexibly adjusted and set according to actual requirements, and is not limited herein.

Wherein, when a1 is greater than 15mm and a2 is greater than 5mm, the wind breaking effect is reduced; when a1 is less than 3mm and a2 is less than 1mm, the processing difficulty will be increased.

In one embodiment, a centrifugal fan, the centrifugal fan comprising: the scroll 20 and the impeller 30 provided in the scroll 20, the impeller 30 including a front plate 31, a rear plate 32, and blades of the centrifugal fan of any of the above embodiments, the blades being provided between the front plate 31 and the rear plate 32.

In the centrifugal fan, since the noise-reducing line segment 111 is disposed at the first side edge 11, the noise-reducing line segment 111 is disposed at the upper end 13 and/or the lower end 14 of the blade 10, and the space S between the noise-reducing line segment 111 and the central axis of the centrifugal fan is in a decreasing trend along the air inlet direction f, that is, the first side edge 11 at the upper end 13 and/or the lower end 14 of the blade 10 is provided with a chamfer, so that on one hand, an avoidance space can be formed, the inner diameter of the air inlet ring 34 is designed to be relatively larger, and the air inflow is more sufficient; on the other hand, the length of the noise reduction line segment 111 is longer than that of a vertical side parallel to the central axis, so that the number of the arranged saw teeth 112 is larger, and wind breaking is facilitated; in addition, when the airflow impacts the first side edge 11, each sawtooth 112 on the noise reduction line segment 111 can avoid the airflow to impact the first side edge 11 of the blade at the same time, so that the total noise frequency generated when the airflow impacts the blade is dispersed, and the pneumatic noise reduction effect is better.

In one embodiment, impeller 30 further includes a middle disk 33 located between front disk 31 and rear disk 32. The center plate 33 is provided with a plurality of mounting holes (not shown) into which the respective blades are inserted and fixed.

In one embodiment, a range hood includes the centrifugal fan of any of the embodiments described above.

In the above range hood, since the first side edge 11 is provided with the noise reduction line segment 111, the noise reduction line segment 111 is arranged at the upper end 13 and/or the lower end 14 of the blade 10, and the space S between the noise reduction line segment 111 and the central axis of the centrifugal fan is in a decreasing trend along the air inlet direction f, that is, the first side edge 11 of the upper end 13 and/or the lower end 14 of the blade 10 is provided with the chamfer, so that on one hand, an avoidance space can be formed, the inner diameter of the air inlet ring 34 is designed to be relatively larger, and the air inflow is more sufficient; on the other hand, the length of the noise reduction line segment 111 is longer than that of a vertical side parallel to the central axis, so that the number of the arranged saw teeth 112 is larger, and wind breaking is facilitated; in addition, when the airflow impacts the first side edge 11, each sawtooth 112 on the noise reduction line segment 111 can avoid the airflow to impact the first side edge 11 of the blade at the same time, so that the total noise frequency generated when the airflow impacts the blade is dispersed, and the pneumatic noise reduction effect is better.

In the description of the present application, it should be understood that, if there are terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., these terms refer to the orientation or positional relationship based on the drawings, which are merely for convenience of description and simplification of description, and do not indicate or imply that the apparatus or element referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present application.

Furthermore, the terms "first," "second," and the like, if any, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present application, the terms "plurality" and "a plurality" if any, mean at least two, such as two, three, etc., unless specifically defined otherwise.

In this application, unless explicitly stated and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly. For example, the two parts can be fixedly connected, detachably connected or integrated; can be mechanically or electrically connected; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. The specific meaning of the terms in this application will be understood by those of ordinary skill in the art as the case may be.

In this application, unless expressly stated or limited otherwise, the meaning of a first feature being "on" or "off" a second feature, and the like, is that the first and second features are either in direct contact or in indirect contact through an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.

It will be understood that if an element is referred to as being "fixed" or "disposed" on another element, it can be directly on the other element or intervening elements may also be present. If an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used herein, if any, are for descriptive purposes only and do not represent a unique embodiment.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples only represent a few embodiments of the present application, which are described in more detail and are not to be construed as limiting the scope of the claims. It should be noted that it would be apparent to those skilled in the art that various modifications and improvements could be made without departing from the spirit of the present application, which would be within the scope of the present application. Accordingly, the scope of protection of the present application is to be determined by the claims appended hereto.

Claims (10)

1. The utility model provides a blade of centrifugal fan, its characterized in that, blade (10) are equipped with and are close to centrifugal fan's central axis first side edge (11), first side edge (11) are equipped with noise reduction line segment (111), noise reduction line segment (111) arrange in upper end (13) and/or lower extreme (14) of blade (10), noise reduction line segment (111) with centrifugal fan's central axis's interval is the trend of reducing in the edge air inlet direction, be equipped with a plurality of sawtooth (112) of arranging in proper order on noise reduction line segment (111).

2. A centrifugal fan blade according to claim 1, wherein the middle part of the first side edge (11) is provided as a straight edge (113).

3. A blade of a centrifugal fan according to claim 2, wherein the upper end (13) and/or the lower end (14) of the blade (10) is provided with a chamfer, the contour of which comprises the noise reducing line segment (111).

4. A centrifugal fan blade according to claim 3, wherein the chamfer is curved in profile or beveled in an angle to the central axis.

5. A blade for a centrifugal fan according to claim 3, wherein the blade (10) is further provided with a second side edge (12) opposite the first side edge (11) and remote from the central axis of the centrifugal fan, the chamfer profile of the upper end (13) of the blade (10) being formed with a first end point (1311) and a second end point (1312), when the upper end (13) of the blade (10) is provided with a chamfer, the first end point (1311) being located above the second end point (1312);

wherein, the distance between the first side edge (11) and the second side edge (12) is set as D, and the vertical distance between the first end point (1311) and the extension line of the straight line edge (113) is set as D1, and D1/D is less than or equal to 0.5;

the distance between the top edge (132) of the blade (10) and the bottom edge (142) of the blade (10) is H, and the vertical distance between the second end point (1312) and the top edge (132) of the blade (10) is H1, wherein H1/H is less than or equal to 0.5.

6. Blade of a centrifugal fan according to claim 3 or 5, wherein the blade (10) is further provided with a second side edge (12) opposite the first side edge (11) and remote from the central axis of the centrifugal fan, the chamfer profile of the lower end (14) of the blade (10) being formed with a third end point (1411) and a fourth end point (1412), when the lower end (14) of the blade (10) is provided with a chamfer, the third end point (1411) being located above the fourth end point (1412);

wherein the distance between the first side edge (11) and the second side edge (12) is set as D, and the vertical distance between the fourth end point (1412) and the extension line of the straight line edge (113) is set as D2, wherein D2/D is less than or equal to 0.5;

the distance between the top edge (132) of the blade (10) and the bottom edge (142) of the blade (10) is H, and the vertical distance between the third end point (1411) and the bottom edge (142) of the blade (10) is H2, wherein H2/H is less than or equal to 0.4.

7. The blade of a centrifugal fan according to claim 1, wherein the serrations (112) are one or more of circular arc-shaped, pointed, wavy, fang Bozhuang, S-shaped and W-shaped.

8. The blade of a centrifugal fan according to claim 7, wherein when the serrations (112) are arc-shaped, the serrations (112) form a plurality of arc-shaped recesses (1121), the depth of each arc-shaped recess (1121) is set to a1, and the pitch of apexes (1122) of adjacent two of the serrations (112) is set to a2, wherein 3 mm.ltoreq.a1.ltoreq.15mm, 1 mm.ltoreq.a2.ltoreq.5mm.

9. A centrifugal fan, the centrifugal fan comprising: a volute (20) and an impeller (30) arranged within the volute (20), the impeller (30) comprising a front disc (31), a rear disc (32) and blades of the centrifugal fan according to any one of claims 1 to 8, the blades being arranged between the front disc (31) and the rear disc (32).

10. A range hood comprising the centrifugal fan of claim 9.