CN206539534U - Blade, centrifugal blower fan blade wheel, centrifugal blower and range hood - Google Patents

Abstract

The utility model discloses a kind of blade, centrifugal blower fan blade wheel, centrifugal blower and range hood, the blade includes the blade body of tabular extendable in the longitudinal direction, the cross section profile of blade body is arc, blade body has first side and the second side opposite with first side in horizontal direction, arc includes segmental arc and offset segment, segmental arc extends from the second side to first side, offset segment is inclined to the inner side of segmental arc from the end of segmental arc and extends to first side, the first side of blade body is provided with flange, outside bending of the flange from first side towards segmental arc, and extend towards the second side of blade body.Offset segment causes blade in air-flow direction of flow one blunt aerofoil profile leading edge of formation with the part flange on the inside of segmental arc, so that the medial surface of the blade provided with flange can cater to air-flow to, suppress the flow separation of air-flow, improve the air performance of impeller and centrifugal blower, noise level is reduced, optimizes cost.

Description

Blade, centrifugal blower fan blade wheel, centrifugal blower and range hood

Technical field

The utility model is related to exhaust equipment, in particular it relates to a kind of blade, centrifugal blower fan blade wheel, centrifugal blower and suction Lampblack absorber.

Background technology

The blower fan that most range hoods are used is centrifugal blower, because the blast that centrifugal blower is provided is relatively large, And the features such as with compact conformation, pressure coefficient and high discharge coefficient, thus suitable for the requirement of range hood.Wherein, impeller For the core building block of centrifugal blower, the quality of its performance directly affects the air performance and noise of range hood, and impeller The blade of upper assembling is the key for determining centrifugal blower fan blade wheel performance.The rotation that usual impeller passes through so that air-flow enters impeller Center, and trailing edge 14 ' is flowed to by blade inlet edge 13 ', air-flow is discharged.

But be made more than the centrifugal blower of the prior art for absorbing cigarette machine of Metal plate, blade is typically designed to circle The hardened structure of arc, referring to Fig. 1 and Fig. 2, this circular arc vane is generally shorter due to leaf road, and in order to obtain accelerating type leaf road The efficiency of impeller is improved, is normally that, with the larger inlet air flow angle of attack, this causes the formation of blade inlet edge 13 ' by blade design Larger adverse pressure gradient, easily flow separation occurs air-flow for edge 13 ' in front of the blade, and whirlpool can be produced between adjacent blades Stream.The flow field of the blade in the prior art simulation result figure shown referring specifically to Fig. 3, because the camber of circular arc vane is excessive, makes The inlet air flow angle of attack it is also larger, streamline leading edge of (suction surface) on the outside of circular arc vane is easily separated from blade, causes air-flow Flow separation occurs for edge 13 ' in front of the blade, and vortex is produced between adjacent blades so that air-flow discharge is not smooth, so as to cause leaf Take turns air hydraulic performance decline, noise increase.

Utility model content

The purpose of this utility model is to provide a kind of blade, centrifugal blower fan blade wheel, centrifugal blower and range hood, the blade Air-flow separation can be suppressed, to improve the air performance of impeller, noise level is reduced, and then improve the performance of centrifugal blower, drop The optimization cost of low centrifugal blower.

To achieve these goals, according to first aspect of the present utility model there is provided a kind of blade, the blade includes edge The blade body of the tabular of longitudinal direction extension, the cross section profile of the blade body is arc, and the blade body is in transverse direction Direction has first side and the second side opposite with the first side, and the arc includes segmental arc and offset segment, described Segmental arc extends from the second side to the first side, and the offset segment is inclined to the arc from the end of the segmental arc Shape section inner side and extend to the first side, the first side of the blade body is provided with flange, the flange from The first side is bent towards the outside of the segmental arc, and is extended towards the second side of the blade body.

Preferably, it is arranged at intervals between the flange and the lateral surface of the blade body.

Preferably, the segmental arc is circular arc.

Preferably, arc transition between the segmental arc and the offset segment；And/or the offset segment and the flange it Between arc transition.

The cross section profile for the flange being preferably located on the outside of the segmental arc is the leading edge of aerofoil profile.

Preferably, in the cross section of the blade, the flange has the marginal point farthest away from the second side, institute It is S1 to state the distance between the end of marginal point and the flange in the direction of the width, and the width of the blade is W, wherein, S1/ W≤1/4, preferably 1/8 to 1/5.

Preferably, offered on the flange and extend and connect the insertion inside and outside the flange along the longitudinal direction Groove.

Preferably, the through slot is located in the region between the first side and the marginal point.

Preferably, the through slot has and is spaced in parallel with each other and is respectively adjacent to the first side in a lateral direction With the first trough rim and the second trough rim of the flange end, first trough rim and the distance of the marginal point in the direction of the width For S2, the width of the blade body is W, wherein, S2/W≤1/4, preferably 0.

Preferably, the distance between first trough rim and second trough rim are 0.8-1.5mm.

Preferably, the length of the through slot in a longitudinal direction is the 1/2 to 4/5 of the length of the blade body.

Preferably, the through slot is the single groove continuously extended along the longitudinal direction.

Preferably, the through slot includes the multiple grooves section discontinuously arranged along the longitudinal direction as a row.

According to second aspect of the present utility model there is provided a kind of centrifugal blower fan blade wheel, the centrifugal blower fan blade wheel includes same Preceding disk and rear disk that axle is set, the centrifugal blower fan blade wheel include multiple above-mentioned blades provided by the utility model, many The individual blade is arranged between the preceding disk and the rear disk, and circumference of multiple blades along the preceding disk It is uniformly distributed, the center of rotation axis of the side of the blade provided with the flange adjacent to the preceding disk.

According to the third aspect of the present utility model, there is provided a kind of centrifugal blower, including spiral case and motor, the centrifugal blower Including above-mentioned centrifugal blower fan blade wheel provided by the utility model, the centrifugal blower fan blade wheel is arranged in the spiral case, described Rear disk is arranged in the rotating shaft of the motor.

In addition, according to fourth aspect of the present utility model there is provided a kind of range hood, the range hood includes this practicality New provided above-mentioned centrifugal blower.

By above-mentioned technical proposal, the utility model is by designing with segmental arc and being inclined to segmental arc blade body The offset segment of inner side, and flange is set on first side, i.e. offset segment causes blade to exist with the part flange on the inside of segmental arc Air-flow direction of flow one blunt aerofoil profile leading edge of formation so that when air-flow by the center of impeller enters fashionable, the blade provided with flange Medial surface can cater to air-flow come to, i.e. so that being oriented to medial surface attachment flowing of most of air-flow along blade, only small portion The bending place that is located at segmental arc on the outside of of the air-flow along flange and the part flange attachment on the outside of segmental arc is divided to flow, thus Effectively suppress the flow separation of air-flow, to improve the air performance of impeller, reduce noise level, and then improve the property of centrifugal blower Can, reduce the optimization cost of centrifugal blower.

Other features and advantages of the utility model will be described in detail in subsequent embodiment part.

Brief description of the drawings

Accompanying drawing is to be further understood for providing to of the present utility model, and constitutes a part for specification, and following Embodiment be used to explain the utility model together, but do not constitute to limitation of the present utility model.In the accompanying drawings：

Fig. 1 is the structural representation of blade of the prior art；

Fig. 2 is the surveys view of blade of the prior art

Fig. 3 is blade flow field simulation result figure of the prior art；

Fig. 4 is the structural representation of the blade according to preferred embodiment of the present utility model；

Fig. 5 and Fig. 6 are Fig. 4 side views；

Fig. 7 is the structural representation of the centrifugal blower fan blade wheel according to preferred embodiment of the present utility model；

Fig. 8 is Fig. 9 decomposing schematic representation；

Fig. 9 is the section view of the centrifugal blower fan blade wheel according to preferred embodiment of the present utility model.

Description of reference numerals

The impeller of 1 blade 2

The flange of 11 blade body 12

The second side of 13 first side 14

15 through slots

The rear disk of disk 22 before 21

The offset segment of 111 segmental arc 112

The trough rim of 151 first trough rim 152 second

153 grooves section A marginal points

Embodiment

Embodiment of the present utility model is described in detail below in conjunction with accompanying drawing.It should be appreciated that herein Described embodiment is merely to illustrate and explained the utility model, is not limited to the utility model.

In the utility model, in the case where not making opposite explanation, the noun of locality used such as " inside and outside " refers to, with arc Based on shape line, the direction towards the arc center of circle is arc shaped inside, and the direction away from the arc center of circle is (dorsal part) on the outside of arc.

Referring to Fig. 4 to Fig. 6, it is shown that according to a kind of blade 1 of preferred embodiment of the present utility model, the blade 1 is wrapped The blade body 11 of tabular extendable in the longitudinal direction is included, the cross section profile of blade body 11 is arc, and blade body 11 exists Horizontal direction has first side 13 and the second side 14 opposite with first side 13, and arc includes segmental arc 111 and biasing Section 112, segmental arc 111 extends from second side 14 to first side 13, and offset segment 112 is inclined to arc from the end of segmental arc 111 The inner side of shape section 111 and extend to first side 13, the first side 13 of blade body 11 is provided with flange 12, flange 12 from The first side 13 is bent towards the outside of segmental arc 111, and is extended towards the second side 14 of blade body 11.

Referring to the structural representation of Fig. 7 impeller, longitudinal direction is the center of rotation axis direction of impeller defined in it, long Spend in the distance of longitudinal direction；Horizontal direction is any direction in the plane perpendicular to the center of rotation axis, width For in the distance of horizontal direction.The blade 1 of tabular is defined as using segmental arc 111 and offset segment 112 as bus along the longitudinal direction The structure type of blade body 11 formed by extension.First side 13 is extendable in the longitudinal direction and neighbouring for offset segment 112 The edge of the center of rotation axis, second side 14 is for the extendable in the longitudinal direction of segmental arc 111 and away from the rotation The edge of heart axis.Wherein, machine-shaping and design for convenience, in preferred embodiment of the present utility model, it is preferable that Segmental arc 111 is circular arc.

Referring to Fig. 1 to Fig. 3, because the camber in the prior art due to circular arc vane is excessive so that the inlet air flow angle of attack Also larger so that in air flow direction blade inlet edge 13 ', to be easily separated from blade surface, causing air-flow, edge 13 ' occurs in front of the blade Flow separation, thus the noise of increase impeller, reduce the air performance of impeller；And because the camber of circular arc vane is excessive, During so that medial surface attachment of the air-flow along circular arc vane is flowed to close to trailing edge 14 ', the fraction is due to inertia and centrifugation Effect produces vortex towards the reflux of blade inlet edge 13 ' between adjacent blades.The rotation that usual impeller passes through so that air-flow enters Enter the center of impeller, and trailing edge 14 ' is flowed to by blade inlet edge 13 ', air-flow is discharged.

The utility model by blade body 11 by designing the inclined of the inner side with segmental arc 111 and deviation segmental arc 111 Put section 112, and the setting flange 12 on first side 13.That is, because offset segment 112 is biased towards the inner side of segmental arc 111, Outside of the flange 12 by first side 13 initially towards segmental arc 111 is bent, i.e., referring to being to be folded upward in Fig. 5 and Fig. 6, then Extend towards the second side 14 of blade body 11 so that on the cross section of blade, flange 12 forms blunt with blade body 11 Aerofoil profile leading edge.So that compared with the air-flow angle of attack at circular arc vane import in the prior art, offset segment 112 is with being located at segmental arc The part flange 12 of 111 inner sides is collectively forming the less inlet air flow angle of attack.And because flange 12 is towards the outer of segmental arc 111 Lateral bending is rolled over, and extends towards the second side 14 of blade body 11 so that when air-flow by the center of impeller 2 enters fashionable, air-flow is first First flow to first side 13 and the medial surface energy of blade 1 of the intersection (i.e. the bending place of flange 12) provided with flange 12 of flange 12 Enough cater to air-flow come to.I.e. so that be oriented to medial surface attachment flowing of most of air-flow along blade 1, only fraction air-flow Adhere to stream along the bending place for being located at the outside of segmental arc 111 of flange 12 and the part flange 12 positioned at the outside of segmental arc 111 It is dynamic.Thus effectively suppress the flow separation of air-flow, to improve the air performance of impeller, reduce noise level, and then improve centrifugation The performance of blower fan, reduces the optimization cost of centrifugal blower.

Because easily edge 13 ' is also easy to produce flow separation in front of the blade in the prior art, therefore the utility model is by the edge of flange 12 Longitudinal direction extends, and is arranged in blade body 11 at the position of neighbouring first side 13.So that extendable in the longitudinal direction turns over Side 12 can reduce the inlet air flow angle of attack of blade 1 at the position of neighbouring first side 13 so that air-flow is along along blade 1 Side flow, to suppress the flow separation of air-flow.

In order that must provided with flange 12 blade 1 medial surface can preferably cater to air-flow come to, i.e. so that be oriented to Medial surface attachment flowing of most of air-flow along blade 1, it is preferable that between the end of flange 12 and the lateral surface of blade body 11 It is arranged at intervals.Due to being arranged at intervals between flange 12 and the lateral surface of blade body 11 so that the bending place of increase flange 12 Area.When air-flow enters the center of impeller, air-flow flows first to the bending place of flange 12, due to the face of the bending place of flange 12 Product increase, is more easy to be oriented to adhere to along the medial surface of blade 1 by most of air-flow to flow, thus effectively suppresses the flowing point of air-flow From.The end of wherein flange 12 refers to the elongated end of flange 12.

Preferably, arc transition between segmental arc 111 and offset segment 112；And/or circle between offset segment 112 and flange 12 Arc transition.Arc transition will be set between segmental arc 111 and offset segment 112 and/or between offset segment 112 and flange 12, made Obtaining air-flow can be more easy to smoothly be oriented to, the further area of the bending place of increase flange 12, and due to arc transition, So that air-flow is alleviated or avoided for the friendship between segmental arc 111 and offset segment 112 and/or between offset segment 112 and flange 12 Stress concentration at boundary, and then extend the service life of blade, it is also possible that the overall appearance of blade is more attractive in appearance.In this reality With in new preferred embodiment, it is preferable that arc transition offset segment 112 and flange between segmental arc 111 and offset segment 112 Equal arc transition between 12.It is further preferred that the curvature of the circular arc of transition and circular arc between offset segment 112 and flange 12 Ratio between segmental arc 111 is more than 0.012.

Wherein, flange 12 can be set when extending towards the second side 14 of blade body 11 close to blade body 11, Positioned at the leading edge that the cross section profile of the flange 12 in the outside of segmental arc 111 is suitable aerofoil profile under Impeller Design operating mode, wherein described Aerofoil profile leading edge be airfoil fan windward side edge.In preferred embodiment of the present utility model, it is preferable that position The cross section profile of flange 12 on the outside of segmental arc 111 is the arc concentric with segmental arc 111.Make it easy to flange 12 Processing and design, flow while also enabling the air-flow in the region in the outside of segmental arc 111 to adhere to along the arc, thus Further reduce or suppress the flow separation of air-flow.

Because the length of flange 12 is shorter, the effect for reducing the inlet air flow angle of attack and guiding air-flow is not had, flange 12 Length is longer, causes the chatter of the flange 12 positioned at the outside of segmental arc 111, increases noise, therefore of the present utility model preferred In embodiment, in the cross section of blade, flange 12 has the marginal point A farthest away from second side 14, and marginal point A is with turning over Distance between the end on side 12 in the direction of the width is S1, and the width of blade is W, wherein, S1/W≤1/4, preferably 1/8 to 1/5.Wherein, the width W of blade is the width of whole blade, i.e. including blade body 11 and flange 12.

Because the camber of circular arc vane in the prior art is excessive so that medial surface attachment stream of the air-flow along circular arc vane When moving to close to trailing edge 14 ', the fraction is because inertia and centrifugal action are towards the reflux of blade inlet edge 13 ', in adjacent blades Between produce vortex.Therefore in order to further suppress the flow separation of air-flow, it is preferable that offered along the longitudinal direction on flange 12 Through slot 15 inside and outside extension and connection flange 12.So that the medial surface of flange 12 is interconnected with lateral surface, in air-flow When flowing into the center of impeller, medial surface attachment flowing of most of air-flow along blade 1, also fraction passes through through slot 15 The lateral surface of blade body 11 is flowed to, so as to form larger inverse between reducing the inner and outer of the blade 1 provided with flange 12 Pressure gradient, only fraction air-flow are along flange 12 positioned at the bending place in the outside of segmental arc 111 and positioned at the outside of segmental arc 111 Part flange 12 attachment flowing, to suppress flow separation of the air-flow at flange 12.Further, since through slot 15 connects flange 12 medial surface and lateral surface so that the fraction in the outside of flange 12 is by through slot 15 towards the outside of blade body 11 Surface current is moved, to the air-flow Implantation Energy of the lateral surface of blade body 11, to overcome above-mentioned adverse pressure gradient, to suppress the stream of air-flow Dynamic separation, prevents from producing vortex between adjacent blades so that air-flow can flow to second along the lateral surface attachment of adjacent blades 1 Side 14, air-flow is discharged.

It should be noted that due to offering through slot 15 on flange 12, inside and outside connection flange 12, Therefore the end of flange 12 can not be caused to be contacted with the lateral surface of blade body 11 and intersecting, i.e. flange 12 and blade body 11 Lateral surface between be arranged at intervals.

Preferably, in the cross section of blade 1, flange 12 has the marginal point A farthest away from second side 14, through slot 15 In region between first side 13 and marginal point A.Region between first side 13 and marginal point A is located at second Flange 12 between side 14 and marginal point A below line.So that when air-flow flows into the center of impeller, flowing to flange 12 Fraction flows to the lateral surface of blade body 11 by through slot 15, thus reduce the inner side of the blade 1 provided with flange 12 with Larger adverse pressure gradient is formed between outside, suppresses the flow separation of air-flow.

In the prior art circular arc vane due to camber it is larger so that there is larger inverse pressure between the interior lateral surface of blade Gradient, fraction can not overcome the adverse pressure gradient and cause air-flow flow separation formed here, i.e. the fraction can not The arcuately medial surface attachment flowing of blade.It is spaced in parallel with each other it is therefore preferred that through slot 15 has in a lateral direction And it is respectively adjacent to the first trough rim 151 and the second trough rim 152 of first side 13 and the end of flange 12, the first trough rim 151 and edge The distances of point A in the direction of the width are S2, and the width of blade body 11 is W, wherein, S2/W≤1/4, preferably 0.So that part Air-flow flows to the lateral surface of blade 1 by through slot 15, and the air-flow Implantation Energy of adverse pressure gradient can not be overcome by thinking, so as to overcome Inverse pressure, suppresses the flow separation of air-flow.In preferred embodiment of the present utility model, S2/W is 0, i.e. the first trough rim 151 with Marginal point A in the direction of the width apart from S2 be 0.

According to different operating modes, the distance between first trough rim 151 and the second trough rim 152 of through slot 15 can specifically be set Meter.In the utility model, it is preferable that between the first trough rim 151 and the second trough rim 152 (i.e. the width of through slot 15) away from From for 0.8-1.5mm.In the blade shown in Fig. 4 to Fig. 6, the distance between the first trough rim 151 and the second trough rim 152 are 1.0mm.The inverse pressure to be formed can be enough to overcome as long as ensuring the width of the through slot 15 of design, the flow separation for suppressing air-flow is Can.

In order to further ensure that through slot 15 can be enough to overcome inverse pressure, suppress air current flow separation, except in terms of width Outside being improved, it can also be improved in length direction.Preferably, the length of through slot 15 in a longitudinal direction is leaf The 1/2 to 4/5 of the length of piece body 11.It is further preferred that in order to ensure the intensity of blade body 11, through slot 15 is along longitudinal side To centrally arranged, i.e. the two ends of through slot 15 and two end faces of blade body 11 have certain distance so that blade body 11 It is not easily broken or bends.

Through slot 15 can have a variety of arrangements, in a kind of embodiment of the present utility model, and through slot 15 is edge The single groove that longitudinal direction continuously extends.I.e. the number of through slot 15 is the insertion groove of a strip, and such a embodiment is fitted Smaller for blade dimensions, the through slot 15 for opening up an entirety does not interfere with the strength and stiffness of blade body 11.Wherein, Blade body 11 can be made up of the high polymer material of Metal plate including plastics.Through slot 15 can be with the one of blade body 11 Shaping, also can first formed blades body 11, then by modes such as punching presses, through slot 15 is molded in blade body 11.

But the utility model is not limited thereto, in another embodiment of the present utility model, through slot 15 includes Along the longitudinal direction, discontinuously arrangement is a multiple grooves section 153 arranged.Reinforcement is formed between adjacent slot section 153, to strengthen The strength and stiffness of blade body 11.Such a embodiment is applied to larger-size blade, by the way that through slot 15 is designed as Multiple groove sections 153, to ensure the strength and stiffness of blade body 11.In preferred embodiment of the present utility model, referring to figure 4, through slot 15 includes the two grooves section 153 discontinuously arranged along the longitudinal direction as a row.Wherein it is preferred to, groove section 153 For rectangular channel, or Long Circle etc..

In addition, referring to Fig. 7 to Fig. 9, the utility model additionally provides a kind of centrifugal blower fan blade wheel, including before being coaxially disposed Disk 21 and rear disk 22, the centrifugal blower fan blade wheel include multiple above-mentioned blades 1 provided by the utility model, multiple blades 1 be arranged on before between disk 21 and rear disk 22, and circumference of the multiple blades 1 along preceding disk 21 is uniformly distributed, provided with flange Center of rotation axis of the side of 12 blade 1 adjacent to preceding disk 21.Inertia suction and centrifugal force are formed by the rotation of impeller, So that air-flow initially enters the central part of preceding disk 21, so as to cause air flow direction flange 12 by inertia suction and centrifugal force The side of blade 1, and then medial surface attachment flowing of most of air-flow along blade 1, fraction is by through slot 12 towards leaf The lateral surface flowing of piece 1, to overcome the adverse pressure gradient of the formation of blade 1, reduces flow separation, leaf weight and the phase of air-flow Stream pressure between adjacent blade, prevents from producing vortex between adjacent blades, to improve the air performance of impeller, reduces noise Level and leaf weight.

Wherein, in another embodiment of the present utility model, also can be set between preceding disk 21 and rear disk 22 to A few telophragma, multiple blades are separately positioned on the both sides of telophragma.Preferably, the quantity phase of the blade of telophragma both sides Deng it is further preferred that the interlaced arrangement of the blade of telophragma both sides.

The utility model additionally provides a kind of centrifugal blower including spiral case and motor, and it is new that centrifugal blower also includes this practicality The above-mentioned centrifugal blower fan blade wheel that type is provided, the centrifugal blower fan blade wheel is arranged in the spiral case, and rear disk 22 is arranged on motor Rotating shaft on.Because the blade processing that the utility model is provided is convenient and simple, and can effectively so that the separation of air-flow, because And the performance of centrifugal blower can be improved, reduce the optimization cost of centrifugal blower.

Wherein, centrifugal blower, in another aspect of the present utility model, the centrifugal blower can be answered applied to more multi-field For culinary cuisine field, it is preferable that applied in range hood, i.e. range hood is included on provided by the utility model State centrifugal blower.So that range hood suction oil smoke effect more preferably, be not susceptible to oil smoke return or oil smoke can not and When the phenomenon discharged, the user for considerably increasing range hood uses friendly.

Preferred embodiment of the present utility model is described in detail above in association with accompanying drawing, still, the utility model is not limited Detail in above-mentioned embodiment, can be to skill of the present utility model in range of the technology design of the present utility model Art scheme carries out a variety of simple variants, and these simple variants belong to protection domain of the present utility model.

It is further to note that each particular technique feature described in above-mentioned embodiment, in not lance In the case of shield, it can be combined by any suitable means.In order to avoid unnecessary repetition, the utility model is to each Possible combination is planted no longer separately to illustrate.

In addition, can also be combined between a variety of embodiments of the present utility model, as long as it is not disobeyed Thought of the present utility model is carried on the back, it should equally be considered as content disclosed in the utility model.

Claims (18)

1. blade, the blade includes the blade body (11) of tabular extendable in the longitudinal direction, the blade body (11) it is transversal Face profile is arc, and the blade body (11) has first side (13) and opposite with the first side (13) in horizontal direction Second side (14), it is characterised in that the arc include segmental arc (111) and offset segment (112), the segmental arc (111) from the second side (14) to the first side (13) extend, and the offset segment (112) is from the segmental arc (111) end is inclined to the inner side of the segmental arc (111) and extends to the first side (13), the blade body (11) The first side (13) be provided with flange (12), the flange (12) is from the first side (13) towards the segmental arc (111) outside bending, and extend towards the second side (14) of the blade body (11).

2. blade according to claim 1, it is characterised in that the end of the flange (12) and the blade body (11) Lateral surface between be arranged at intervals.

3. blade according to claim 2, it is characterised in that the segmental arc (111) is circular arc.

4. blade according to claim 3, it is characterised in that between the segmental arc (111) and the offset segment (112) Arc transition；And/or

Arc transition between the offset segment (112) and the flange (12).

5. blade according to claim 3, it is characterised in that flange (12) on the outside of the segmental arc (111) Cross section profile is the leading edge of aerofoil profile.

6. blade as claimed in any of claims 1 to 5, it is characterised in that in the cross section of the blade, institute Flange (12) is stated with the marginal point (A) farthest away from the second side (14), the marginal point (A) and the flange (12) Distance between end in the direction of the width is S1, and the width of the blade is W, wherein, S1/W≤1/4.

7. blade according to claim 6, it is characterised in that the S1/W is 1/8 to 1/5.

8. blade according to claim 6, it is characterised in that offer and prolong along the longitudinal direction on the flange (12) Stretch and connect the through slot (15) inside and outside the flange (12).

9. blade according to claim 8, it is characterised in that in the cross section of the blade, the through slot (15) In region between the first side (13) and the marginal point (A).

10. blade according to claim 9, it is characterised in that the through slot (15) has each other in a lateral direction Abreast it is spaced and is respectively adjacent to the first side (13) and first trough rim (151) and the second groove of the flange (12) end Side (152), first trough rim (151) is S2, the blade body with the distance of the marginal point (A) in the direction of the width (11) width is W, wherein, S2/W≤1/4.

11. blade according to claim 10, it is characterised in that the S2/W is 0.

12. blade according to claim 10, it is characterised in that first trough rim (151) and the second trough rim (152) it Between distance be 0.8-1.5mm.

13. blade according to claim 8, it is characterised in that the length of the through slot (15) in a longitudinal direction is The 1/2 to 4/5 of the length of the blade body (11).

14. blade according to claim 8, it is characterised in that the through slot (15) is continuous along the longitudinal direction The single groove of extension.

15. blade according to claim 8, it is characterised in that the through slot (15) includes disconnected along the longitudinal direction Continuous arrangement is a multiple grooves section (153) arranged.

16. a kind of centrifugal blower fan blade wheel, the centrifugal blower fan blade wheel includes the preceding disk (21) and rear disk (22) being coaxially disposed, Characterized in that, the centrifugal blower fan blade wheel includes multiple blades according to any one in claim 1 to 15, it is multiple The blade is arranged between the preceding disk (21) and the rear disk (22), and multiple blades are along the preceding disk (21) circumference is uniformly distributed, and the side of the blade provided with the flange (12) is in the rotation of the preceding disk (21) Heart axis.

17. a kind of centrifugal blower, including spiral case and motor, it is characterised in that the centrifugal blower is included according to claim 16 Described centrifugal blower fan blade wheel, the centrifugal blower fan blade wheel is arranged in the spiral case, and the rear disk (22) is arranged on described In the rotating shaft of motor.

18. a kind of range hood, it is characterised in that the range hood includes centrifugal blower according to claim 17.