阅读说明：本技术 轴流风叶和空调室外机 (Axial flow fan blade and air conditioner outdoor unit ) 是由 周伟峰 周孝华 林辉 董龙 高旭 代文杰 于 2020-03-31 设计创作，主要内容包括：本发明公开一种轴流风叶和空调室外机。其中,该轴流风叶包括轮：毂和若干叶片,若干叶片均设于轮毂的外周壁,且若干叶片沿轮毂的周向间隔设置,其中,定义一所述叶片为第一叶片,在所述轴流风叶的旋转方向上,定义与所述第一叶片相邻的另一所述叶片为第二叶片,所述第一叶片的前缘上最凸出的点、所述第二叶片的前缘上最凸出的点以及所述轮毂的中心所构成的圆心角为叶片夹角,相邻的三个所述叶片分别独立形成的所述叶片夹角中,两个相邻的所述叶片夹角分别为α和β,满足条件：α≠β。本发明技术方案降低了目前轴流风叶旋转噪音的叠加,以避免该轴流风叶产生异常噪音。(The invention discloses an axial flow fan blade and an air conditioner outdoor unit, wherein the axial flow fan blade comprises a wheel, a hub and a plurality of blades, wherein the blades are arranged on the peripheral wall of the hub at intervals along the circumferential direction of the hub, one blade is defined as a first blade, the other blade adjacent to the first blade is defined as a second blade in the rotating direction of the axial flow fan blade, the most convex point on the front edge of the first blade, the most convex point on the front edge of the second blade and the center of the hub form a central angle of the blade, the included angles of the two adjacent blades in the blade included angles formed by the three adjacent blades are α and β respectively, and the requirement that α is not equal to β is met.)

1. An axial flow fan blade, comprising:

a hub;

the blades are arranged on the outer peripheral wall of the hub and are arranged at intervals along the circumferential direction of the hub;

the axial-flow fan blade comprises a hub, a first blade, a second blade, a blade support and a blade, wherein one blade is defined as a first blade, the other blade adjacent to the first blade is defined as a second;

among the blade included angles formed by the three adjacent blades respectively and independently, the included angles of the two adjacent blades are α and β respectively, so that the condition that α is not equal to β is met.

2. The axial-flow fan blade of claim 1, wherein 170 ° - α + β ° -190 °, and 85 ° - α -95 °.

3. The axial-flow fan blade according to claim 1, wherein a sawtooth part and a convex part are sequentially arranged on the trailing edge of the fan blade at intervals along the direction far away from the hub, and the sawtooth part is arranged between two opposite ends of the trailing edge;

wherein the sawtooth part comprises a plurality of sawteeth which are arranged at intervals in sequence along the direction far away from the hub.

4.The axial-flow fan blade according to claim 3, wherein the distance between the point on the protrusion farthest from the center of the hub and the center of the hub is defined as R₀；

Defining the distance between the point of the sawtooth part closest to the center of the hub and the center of the hub as R₁；

Then the condition is satisfied: 0.2R₀<R₁<0.45R₀。

5. The axial-flow fan blade of claim 4, wherein the distance between the point of the sawtooth part farthest from the center of the hub and the center of the hub is defined as R₂；

Then the condition is satisfied: 0.6R₀<R₂<0.9R₀。

6. The axial flow fan blade according to claim 5, wherein in two adjacent blades, the point of the serration closest to the center of the hub is not equidistant from the center of the hub.

7. The axial flow fan blade according to claim 5, wherein in two adjacent blades, the point of the serration which is farthest from the center of the hub is not equidistant from the center of the hub.

8. The axial-flow fan blade according to claim 3, wherein, in a projection in the axial direction of the hub, the outer edges of the serrations form a Bezier curve;

and/or, in a projection along the axial direction of the hub, the outer edge of the convex part forms a Bezier curve.

9. The axial-flow fan blade according to any one of claims 1 to 8, wherein the blade is provided with four blades, in the rotation direction of the axial-flow fan blade, the first blade, the second blade, the third blade and the fourth blade;

in the rotating direction of the axial flow fan blade, a central angle formed by a most convex point on the front edge of the first blade, a most convex point on the front edge of the fourth blade and the center of the hub is defined as a first blade included angle;

in the rotating direction of the axial flow fan blade, a central angle formed by a most convex point on the front edge of the third blade, a most convex point on the front edge of the second blade and the center of the hub is defined as a third blade included angle;

in the rotating direction of the axial flow fan blade, a central angle formed by a most convex point on the front edge of the second blade, a most convex point on the front edge of the first blade and the center of the hub is defined as a second blade included angle;

in the rotating direction of the axial flow fan blade, a central angle formed by a most convex point on the front edge of the fourth blade, a most convex point on the front edge of the third blade and the center of the hub is defined as a fourth blade included angle;

wherein the included angle of the first blade is equal to the included angle of the third blade, and both the included angles are α;

the second blade included angle with the fourth blade included angle equals, and is β.

10. An outdoor unit of an air conditioner, comprising the axial-flow fan blade recited in any one of claims 1 to 9.

Technical Field

The invention relates to the technical field of refrigeration equipment, in particular to an axial flow fan blade and an air conditioner outdoor unit applying the same.

Background

The axial flow fan blade used by the existing air conditioner outdoor unit generally comprises a hub and a plurality of blades, wherein the plurality of blades are uniformly distributed along the circumferential direction of the hub respectively, and the geometric shape, the pneumatic parameter and other data of the plurality of blades are uniform.

The above is only for the purpose of assisting understanding of the technical solutions of the present application, and does not represent an admission that the above is prior art.

Disclosure of Invention

The invention mainly aims to provide an axial flow fan blade, aiming at reducing the superposition of the rotation noise of the conventional axial flow fan blade so as to avoid the generation of abnormal noise of the axial flow fan blade.

In order to achieve the above object, the present invention provides an axial flow fan blade, including:

a hub;

the blades are arranged on the outer peripheral wall of the hub and are arranged at intervals along the circumferential direction of the hub;

the axial-flow fan blade comprises a hub, a first blade, a second blade, a blade support and a blade, wherein one blade is defined as a first blade, the other blade adjacent to the first blade is defined as a second;

among the blade included angles formed by the three adjacent blades respectively and independently, the included angles of the two adjacent blades are α and β respectively, and the requirement that α is not equal to β is met.

In one embodiment of the invention, 170 DEG- α + β DEG-190 DEG, and 85 DEG- α DEG-95 deg.

In an embodiment of the present invention, along a direction away from the hub, a plurality of saw tooth portions and protruding portions are sequentially disposed at intervals on a trailing edge of the blade, and the saw tooth portions are disposed between two opposite ends of the trailing edge;

wherein the sawtooth part comprises a plurality of sawteeth which are arranged at intervals in sequence along the direction far away from the hub.

In an embodiment of the present invention, a distance between a point on the protruding portion closest to the center of the hub and the center of the hub is defined as R₀；

Defining the distance between the point of the sawtooth part closest to the center of the hub and the center of the hub as R₁；

Then the condition is satisfied: 0.2R₀<R₁<0.45R₀。

In an embodiment of the present invention, a distance between a point of the sawtooth portion farthest from the center of the hub and the center of the hub is defined as R₂Then the condition is satisfied: 0.6R₀<R₂<0.9R₀。

In an embodiment of the present invention, in two adjacent blades, a point on the serration closest to the center of the hub is not equidistant from the center of the hub.

In an embodiment of the invention, in two adjacent blades, a point of the sawtooth part farthest from the center of the hub is not equidistant from the center of the hub.

In an embodiment of the invention, the outer edge of the sawtooth forms a bezier curve in a projection along the axial direction of the hub;

and/or, in a projection along the axial direction of the hub, the outer edge of the convex part forms a Bezier curve.

In an embodiment of the present invention, the blades are provided with four blades, and in a rotation direction of the axial flow fan blade, the four blades are respectively the first blade, the second blade, the third blade and the fourth blade;

in the rotating direction of the axial flow fan blade, a central angle formed by a most convex point on the front edge of the first blade, a most convex point on the front edge of the fourth blade and the center of the hub is defined as a first blade included angle;

in the rotating direction of the axial flow fan blade, a central angle formed by a most convex point on the front edge of the third blade, a most convex point on the front edge of the second blade and the center of the hub is defined as a third blade included angle;

in the rotating direction of the axial flow fan blade, a central angle formed by a most convex point on the front edge of the second blade, a most convex point on the front edge of the first blade and the center of the hub is defined as a second blade included angle;

in the rotating direction of the axial flow fan blade, a central angle formed by a most convex point on the front edge of the fourth blade, a most convex point on the front edge of the third blade and the center of the hub is defined as a fourth blade included angle;

wherein the included angle of the first blade is equal to the included angle of the third blade, and both the included angles are α;

the second blade included angle with the fourth blade included angle equals, and is β.

The invention also provides an air conditioner outdoor unit, which comprises an axial flow fan blade, wherein the axial flow fan blade comprises:

a hub;

the blades are arranged on the outer peripheral wall of the hub and are arranged at intervals along the circumferential direction of the hub;

the axial-flow fan blade comprises a hub, a first blade, a second blade, a blade support and a blade, wherein one blade is defined as a first blade, the other blade adjacent to the first blade is defined as a second;

among the blade included angles formed by the three adjacent blades respectively and independently, the included angles of the two adjacent blades are α and β respectively, so that the condition that α is not equal to β is met.

The technical proposal of the invention provides an axial flow fan blade, which is characterized in that a plurality of blades are arranged on the peripheral wall of a hub, wherein, in the rotating direction of the axial flow fan blade, one blade is defined as a first blade, the other blade adjacent to the first blade is defined as a second blade, the central angle formed by the most convex point on the front edge of the first blade, the most convex point on the front edge of the second blade and the center of the hub is the blade included angle, and the included angles of two adjacent blades are not equal in the included angles formed by the three adjacent blades respectively and independently, the blades are unevenly distributed around the axis of the hub, so that the problem that the rotational noise is superimposed to generate abnormal noise due to the beat vibration caused by the superposition of the fundamental frequency of the rotational noise and the fixed frequency of the fan blade caused by the periodic air-beating of the evenly distributed blades during high-speed rotation is solved. That is, the technical scheme of the invention reduces the superposition of the rotation noise of the existing axial flow fan blade so as to avoid the abnormal noise generated by the axial flow fan blade.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.

FIG. 1 is a schematic structural diagram of an embodiment of an axial-flow fan blade according to the present invention;

FIG. 2 is a schematic structural diagram of an embodiment of an axial-flow fan blade according to the present invention;

FIG. 3 is a partial graph of the trailing edge of a blade in an axial flow fan according to the present invention;

the reference numbers illustrate:

reference numerals	Name (R)	Reference numerals	Name (R)
				100	Axial flow fan blade	213	Leading edge
10	Wheel hub	214	Trailing edge
				20	Blade	215	Outer edge
21	First blade	22	Second blade
				211	Serration	23	Third blade
212	Projecting part	24	The fourth blade

The implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that, if directional indications (such as up, down, left, right, front, and back … …) are involved in the embodiment of the present invention, the directional indications are only used to explain the relative positional relationship between the components, the movement situation, and the like in a specific posture (as shown in the drawing), and if the specific posture is changed, the directional indications are changed accordingly.

In addition, if there is a description of "first", "second", etc. in an embodiment of the present invention, the description of "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, technical solutions between various embodiments may be combined with each other, but must be realized by a person skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope of the present invention.

The invention provides an axial flow fan blade 100, aiming at reducing the superposition of the rotation noise of the conventional axial flow fan blade 100 so as to avoid the abnormal noise generated by the axial flow fan blade 100.

Referring to fig. 1 to 3, in an embodiment of the axial flow fan blade 100 according to the present invention, the axial flow fan blade 100 includes a hub 10 and a plurality of blades 20, the plurality of blades 20 are disposed on an outer peripheral wall of the hub 10, and the plurality of blades 20 are disposed at intervals along a circumferential direction of the hub 10, where one blade 20 is defined as a first blade 21, another blade 20 adjacent to the first blade 21 is defined as a second blade 22 in a rotation direction of the axial flow fan blade 100, a central angle formed by a most protruded point on a leading edge 213 of the first blade 21, a most protruded point on a leading edge 213 of the second blade 22, and a center of the hub 10 is a blade included angle, and two adjacent blade included angles among the blade included angles formed by three adjacent blades 20 independently are α and β, respectively, which satisfies a condition that α ≠ β.

In this embodiment, the axial flow fan blade 100 may have three, four, five, etc. blades 20, which may be determined according to actual use conditions.

Each blade 20 is provided with a leading edge 213, a trailing edge 214 and an outer edge 215, the leading edge 213 and the trailing edge 214 are distributed on two opposite sides of the blade 20, the outer edge 215 is arranged on one side of the blade 20 facing away from the hub 10, and the blade included angle is the included angle between two adjacent blades 20. The edge of the blade 20 at the foremost end in the rotation direction of the axial flow fan blade 100 is defined as a leading edge 213, and the edge of the blade 20 at the rearmost end in the rotation direction of the axial flow fan blade 100 is defined as a trailing edge 214. The point of the blade 20 farthest from the trailing edge 214 in the rotation direction of the axial-flow fan blade 100 is defined as the most protruding point (e.g., the point M in fig. 2) on the leading edge 213.

Therefore, it can be understood that, in the technical solution of the present invention, the axial flow fan blade 100 is provided with a plurality of blades 20 on the outer circumferential wall of the hub 10, wherein one blade 20 is defined as a first blade 21, another blade 20 adjacent to the first blade 21 is defined as a second blade 22 in the rotation direction of the axial flow fan blade 100, a central angle formed by a most convex point on the front edge 213 of the first blade 21, a most convex point on the front edge 213 of the second blade 22, and the center of the hub 10 is a blade included angle, and in blade included angles formed by three adjacent blades 20 respectively and independently, two adjacent blade included angles are not equal, that is, the plurality of blades 20 are unevenly distributed around the axis of the hub 10, so as to avoid that the plurality of uniformly distributed blades 20 periodically flap air at high speed rotation, and the formed rotation noise overlaps with the fundamental frequency of the fan blade to cause flapping, which causes the superposition of rotation noise, thereby causing a problem of abnormal noise. That is, the technical scheme of the present invention reduces the superposition of the rotational noise of the axial flow fan blade 100 at present, so as to avoid the generation of abnormal noise by the axial flow fan blade 100.

Referring to fig. 1 and fig. 2, in an embodiment of the axial-flow fan blade 100 of the present invention, 170 ° ≦ α + β ≦ 190 °, and 85 ° ≦ α ≦ 95 °.

In the present embodiment, when the plurality of vanes 20 includes four vanes 20, α + β is 180 °.

It can be understood that, in order to reduce the superposition of the rotational noise of the axial flow fan blade 100 and effectively ensure the stability of the axial flow fan blade 100 in the rotating process, the angle between 85 degrees and α degrees is more than or equal to 95 degrees.

The following description will be given by taking α + β as an example of 180 °:

referring to fig. 1 and fig. 2, in an embodiment of the axial-flow fan blade 100 of the present invention, along a direction away from the hub 10, the trailing edge 214 of the blade 20 is sequentially provided with serrations 211 and protrusions 212 at intervals, and the serrations 211 are disposed between two opposite ends of the trailing edge 214;

wherein the saw tooth portion 211 comprises a plurality of saw teeth sequentially arranged at intervals in a direction away from the hub 10.

In this embodiment, three or more saw teeth are sequentially arranged at intervals along the direction away from the hub 10 at the saw tooth portion 211, which can effectively reduce the discrete rotational noise generated by the periodic air flapping of the blades 20 and effectively reduce the superposition of the rotational noise.

The protrusion 212 is disposed between an end of the trailing edge 214 away from the hub 10 and a side of the serration 211 away from the hub 10, and the protrusion 212 may be disposed between an end of the trailing edge 214 away from the hub 10 and a side of the serration 211 away from the hub 10 of each blade 20.

The serrations 211 and the protrusions 212 of the trailing edges 214 of the two adjacent blades 20 are not completely the same, and can be arbitrarily combined within the adjustment range, for example, the trailing edges 214 of the two adjacent blades 20 are provided with the same serrations 211 and different protrusions 212; alternatively, the trailing edges 214 of two adjacent blades 20 are provided with different serrations 211 and the same projections 212; alternatively, the trailing edges 214 of two adjacent blades 20 are provided with different serrations 211 and different projections 212. The specific condition can be determined according to the actual use condition, and is not limited herein.

It can be understood that, in order to further reduce the superposition of the rotational noise, the trailing edge 214 of each blade 20 is sequentially provided with the serrations 211 and the protrusions 212 at intervals, so that the characteristics of the trailing edges 214 in two adjacent blades 20 are different, thereby improving the vortex shedding of the trailing edge 214 of the blade 20, and achieving the purposes of reducing the operating noise and improving the sound quality, and further avoiding the problems that a plurality of uniformly distributed blades 20 periodically beat air when rotating at a high speed, and the fundamental frequency of the formed rotational noise coincides with the fixed frequency of the fan blade to cause beat vibration, which causes the superposition of the rotational noise, thereby generating abnormal noise.

Referring to fig. 1 and fig. 2, in an embodiment of the axial-flow fan blade 100 of the present invention, a distance between a point on the protruding portion 212 farthest from the center of the hub 10 and the center of the hub 10 is defined as R₀；

Defining the distance between the point of the sawtooth part 211 closest to the center of the hub 10 and the center of the hub 10 as R₁；

Then the condition is satisfied: 0.2R₀<R₁<0.45R₀。

In this embodiment, the distance from the farthest point of the protrusion 212 from the center of the hub 10 to the center of the hub 10 is R₀I.e. the maximum radial dimension of the projection is R₀(ii) a The distance between the point of the sawtooth part 211 closest to the center of the hub 10 and the center of the hub 10 is R₁I.e. the smallest radius dimension of the serrations 211 is R₁(ii) a Specifically, when R is₀When the thickness is 260mm, 52mm<R₁<117 mm; or, when R is₀When 300mm, 60mm<R₁<135 mm. Of course, in other embodiments of the present invention, R₀And R₁The conditions may be determined in accordance with actual conditions, and the conditions are not limited to these conditions.

It can be understood that, in order to better improve the vortex shedding of the trailing edge vortex of the blade 20 and to better achieve the purposes of reducing the running noise and improving the sound quality, the distance R between the point of the sawtooth part 211 closest to the center of the hub 10 and the center of the hub 10 is designed₁The following conditions are satisfied: 0.2R₀<R₁<0.45R₀。

Referring to fig. 1 and fig. 2, in an embodiment of the axial-flow fan blade 100 of the present invention, a distance between a point of the sawtooth portion 211 farthest from the center of the hub 10 and the center of the hub 10 is R₂；

Then the condition is satisfied: 0.6R₀<R₂<0.9R₀。

In this embodiment, the distance between the point of the sawtooth portion 211 farthest from the center of the hub 10 and the center of the hub 10 is R₂I.e. the maximum radial dimension of the serrations 211 is R₂. Specifically, when R is₀When the thickness is 260mm, 156mm<R₂<234 mm; or, when R is₀When 300mm, 180mm<R₂<270 mm. Of course, in other embodiments of the present invention, R₀And R₂The conditions may be determined in accordance with actual conditions, and the conditions are not limited to these conditions.

Referring to fig. 1 and fig. 2, in an embodiment of the axial-flow fan blade 100 of the present invention, in two adjacent blades 20, a point on the sawtooth portion 211 closest to the center of the hub 10 is not equidistant from the center of the hub 10.

In this embodiment, in two adjacent blades 20, the number of sawteeth in the sawteeth 211 is not the same, and the lengths of the sawteeth 211 are not the same.

It can be understood that, in order to further ensure that the two adjacent blades 20 have different characteristics of the trailing edge 214, so as to effectively reduce the superposition of the rotational noise and improve the sound quality, the distance between the point of the sawtooth part 211 closest to the center of the hub 10 and the center of the hub 10 in the two adjacent blades 20 is not equal.

Referring to fig. 1 and fig. 2, in an embodiment of the axial-flow fan blade 100 of the present invention, in two adjacent blades 20, a point of the sawtooth portion 211 farthest from the center of the hub 10 is not equidistant from the center of the hub 10.

In this embodiment, the distance between the closest point of the protruding portion 212 to the center of the hub 10 and the distance between the farthest point of the sawtooth portion 211 to the center of the hub 10 and the center of the hub 10 may be coincident, so that when the distance between the closest point of the protruding portion 212 to the center of the hub 10 and the center of the hub 10 is not equal in the two adjacent blades 20, the trailing edges 214 of the two adjacent blades 20 may be provided with different protruding portions 212.

It can be understood that, in order to further ensure that the two adjacent blades 20 have different characteristics of the trailing edge 214, so as to effectively reduce the superposition of the rotational noise and improve the sound quality, the distance between the farthest point of the sawtooth part 211 of the two adjacent blades 20 and the center of the hub 10 is not equal.

Referring to fig. 1 to 3, in an embodiment of the axial-flow fan blade 100 of the present invention, in a projection along the axial direction of the hub 10, the outer edges of the saw teeth form a bezier curve;

and/or, in a projection along the axial direction of the hub 10, the outer edge of the convex portion 212 forms a bezier curve.

In this embodiment, one or more protrusions 212 may be provided, and when a plurality of protrusions 212 are provided, a plurality of protrusions 212 are provided at intervals along the length direction of the trailing edge 214 of the blade 20, and the outer edge of each protrusion 212 in projection along the axial direction of the hub 10 may form a bezier curve.

The bezier curve is a basic tool for computer graphic image modeling, and is one of the basic lines for which graphic modeling is most used. It creates and edits a figure by controlling four points (a start point, an end point, and two intermediate points separated from each other) on a curve. The control line is positioned in the center of the curve, is virtual, the middle of the control line is intersected with the Bezier curve, and the two ends of the control line are control end points. The bezier curve changes the curvature (degree of curvature) of the curve as the end points of both ends are moved; when moving the middle point (i.e., moving the virtual control line), the bezier curve moves uniformly with the start and end points locked. That is, each serration and each protrusion 212 is irregularly shaped.

The outer edge of each serration on the projection in the axial direction of the hub 10 constitutes the bezier curve of the solid line portion in fig. 3, i.e., from P₁A, B and P₄Four control points; the outer edge of each of the projections 212 on projection in the axial direction of the hub 10 constitutes a Bezier curve indicated by a dotted line in FIG. 3, i.e., P₁、P₂、P₃And P₄Four control points.

It can be understood that, in order to further achieve the purpose of reducing the running noise and improving the sound quality of the axial-flow fan blade 100, the outer edge of the sawtooth and/or the outer edge of the protrusion 212 can form a bezier curve in the projection along the axial direction of the hub 10, so as to avoid the overlapping of the rotating noise and the consistent features of the trailing edges 214 of two adjacent blades 20, thereby generating abnormal noise.

With reference to fig. 1 and fig. 2, in an embodiment of the axial-flow fan blade 100 of the present invention, the blades 20 are provided with four blades, and in a rotation direction of the axial-flow fan blade 100, there are the first blade 21, the second blade 22, the third blade 23, and the fourth blade 24;

in the rotation direction of the axial-flow fan blade 100, a central angle formed by a most protruding point on the front edge 213 of the first blade 21, a most protruding point on the front edge 213 of the fourth blade 24, and the center of the hub 10 is defined as a first blade included angle;

in the rotation direction of the axial-flow fan blade 100, a central angle formed by a most convex point on the front edge 213 of the third blade 23, a most convex point on the front edge 213 of the second blade 22, and the center of the hub 10 is defined as a third blade included angle;

in the rotation direction of the axial-flow fan blade 100, a central angle formed by a most protruding point on the front edge 213 of the second blade 22, a most protruding point on the front edge 213 of the first blade 21, and the center of the hub 10 is defined as a second blade included angle;

in the rotation direction of the axial-flow fan blade 100, a central angle formed by a most protruding point on the front edge 213 of the fourth blade 24, a most protruding point on the front edge 213 of the third blade 23, and the center of the hub 10 is defined as a fourth blade included angle;

wherein the included angle of the first blade is equal to the included angle of the third blade, and both the included angles are α;

the second blade included angle with the fourth blade included angle equals, and is β.

In the present embodiment, the characteristics of the trailing edges 214 of the first blade 21, the second blade 22 and the fourth blade 24 are not identical, the characteristics of the trailing edges 214 of the first blade 21 and the third blade 23 may be identical or not identical, and likewise, the characteristics of the trailing edges 214 of the second blade 22 and the fourth blade 24 may be identical or not identical.

When the trailing edge 214 characteristic, the first blade included angle and the third blade included angle of the first blade 21 and the third blade 23 in the rotation direction of the axial flow fan blade 100 are completely the same, and the trailing edge 214 characteristic, the second blade included angle and the fourth blade included angle of the second blade 22 and the fourth blade 24 in the rotation direction of the axial flow fan blade 100 are completely the same, the third blade 23 and the fourth blade 24 rotate 180 degrees around the center of the hub 10 and can coincide with the first blade 21 and the second blade 22.

It can be understood that, in order to effectively reduce the superposition of the rotational noise and also effectively improve the effect that the axial flow fan blade 100 can generate a uniform and stable wind source during the rotation process, four blades 20 are arranged at intervals on the outer circumferential wall of the hub 10.

The present invention further provides an outdoor unit of an air conditioner, which includes axial flow fan blades 100, and the specific structure of the axial flow fan blades 100 refers to the above embodiments, and since the outdoor unit of the air conditioner employs all technical solutions of all the above embodiments, the outdoor unit of the air conditioner at least has all beneficial effects brought by the technical solutions of the above embodiments, and details are not repeated herein.

The above description is only an alternative embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications and equivalents of the present invention, which are made by the contents of the present specification and the accompanying drawings, or directly/indirectly applied to other related technical fields, are included in the scope of the present invention.