Axial-flow fan blade and air conditioning device

Abstract

The utility model relates to the technical field of household appliances, and discloses an axial flow fan blade and an air conditioning device. The multiple blade units are connected to the hub and distributed in the circumferential direction of the hub at intervals, and each blade unit comprises a first blade and a second blade; the first blade comprises a first blade root part, a first blade top part, a first front edge part and a first tail edge part; the second blade comprises a second blade root part, a second blade top part, a second front edge part and a second tail edge part, the second tail edge part is connected with the first front edge part, and the first blade top part and the second blade top part are in a bent arch shape and are arched in the direction away from the hub. According to the axial flow fan blade, the defects that in the related technology, energy loss and noise are large in the using process of the fan blade, and aesthetic fatigue of a user is likely to be caused can be overcome.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of household appliances, and particularly relates to an axial flow fan blade and an air conditioning device. BACKGROUND

[0002] Air conditioning devices, such as air conditioners and air purifiers, generally have fan blades.

[0003] The design of the fan blade has a great influence on the air flow path. In the related art, the blade structure includes a plurality of blades arranged on the circumferential side of the hub. Each blade or each blade and the hub forms a wind passage. The blade includes at least two flow straightening segments on the circumferential side of the wind passage. The suction surface of one of the flow straightening segments is connected to the pressure surface of the other flow straightening segment. However, the tip width of such a blade is relatively narrow, and vortexes are easily generated at the tip of the blade and the trailing edge of the blade, resulting in energy loss and increased noise. Moreover, the shape of such a blade is limited, which easily causes user aesthetic fatigue. SUMMARY

[0004] Therefore, the utility model provides an axial flow fan blade and an air conditioning device to solve the defects in the related art, such as large energy loss and noise during use of the fan blade, and user aesthetic fatigue.

[0005] In a first aspect, the utility model provides an axial flow fan blade, which includes a hub, a plurality of blade units connected to the hub and spaced apart along the circumference of the hub, each blade unit including a first blade and a second blade, the first blade including a first blade root, a first blade tip, a first leading edge, and a first trailing edge, the second blade including a second blade root, a second blade tip, a second leading edge, and a second trailing edge, the second trailing edge being connected to the first leading edge, and the first blade tip and the second blade tip being arc-shaped and arched away from the hub.

[0006] Advantages: The blade unit of the axial flow fan blade in the utility model embodiment is composed of the first blade and the second blade. The blade tip of each blade unit forms an "M" shaped arch shape through double-blade fitting, so that the blade is closer to the petal shape, the aesthetic appearance of the axial flow fan blade is improved, user aesthetic fatigue is broken, and the visual appeal of the product is increased.

[0007] On this basis, and because the blade unit of the axial flow fan blade in the application is fitted by the first blade and the second blade, the tip width of the blade unit can be extended, thereby delaying the formation length of the airflow in the tip area, reducing the scale and order of the airflow shedding from the tip area, and further reducing the discrete noise generated when the axial flow fan blade rotates. Therefore, the axial flow fan blade implemented in the application can reduce the vortex shedding of the blade at the top and trailing edge of the blade, thereby reducing the vortex noise of the blade.

[0008] Therefore, the axial flow fan blade of the application can overcome the defects in the related art that the fan blade has large energy loss and noise during use, and is easy to cause user aesthetic fatigue.

[0009] In an alternative embodiment, the first blade top and the second blade top are connected at the middle position of the blade unit.

[0010] In an alternative embodiment, the maximum outer edge radius of the blade unit is R;

[0011] The intersection between the first blade top and the first trailing edge is a first point, the distance between the first point and the center of the hub is R', and 0.95>R' / R>0.75; and / or,

[0012] The intersection between the second blade top and the second leading edge is a second point, the distance between the second point and the center of the hub is R', and 0.95>R' / R>0.75.

[0013] Beneficial effect: taking the center O of the hub as the base point, different axial cylindrical base circle sections with a radius r are made, the part of the blade that is cut by the base circle section is the blade top of the fan blade, and the axial projection curve of the base circle section with a radius R' is the boundary line of the blade top. When the blade top is in the above-mentioned area, the shape of the axial flow fan blade can be ensured to be closer to the petal shape, and the overall aerodynamic performance of the blade unit is not affected.

[0014] In an alternative embodiment, the intersection between the first blade top and the first trailing edge is a first point, the intersection between the first blade top and the second blade top is a third point, an axial cylindrical base circle section with a radius r is made with the center of the hub as the base point, the line connecting the center and the first point is a first line, the line connecting the center and the third point is a second line, and the angle between the first line and the second line is θ1; the blade top of the first blade is arched in a direction away from the hub to form a first inflection point, and the first inflection point is the center of the hub; and / or,

[0015] The intersection between the second blade top and the second leading edge portion is a second point, the intersection between the first blade top and the second blade top is a third point, the center of the hub is taken as a base point, an axial cylindrical base circle section with a radius of r is drawn, the line connecting the center of the hub and the second point is a fourth line, the line connecting the center of the hub and the third point is a second line, the blade top of the second blade is arched in a direction away from the hub and forms a second inflection point, the line connecting the center of the hub and the second inflection point is a fifth line, the included angle between the fifth line and the fourth line is θM2, and 0.3≤θM2 / θ2≤0.7.

[0016] In an optional embodiment, the outer diameter of the blade unit is D, the diameter of the hub is d, and 0.2≤d / D≤0.35.

[0017] Beneficial effects: In this embodiment, d / D refers to the hub ratio, which is an important design parameter of the axial flow fan. If the hub ratio is too large, the efficiency of the fan will be reduced, and the aerodynamic performance of the whole machine will be reduced. On the contrary, if the hub ratio of the axial flow fan is too small, flow separation will occur at the blade root of the fan blade, causing performance loss of the fan blade. Therefore, by making the hub ratio between 0.2 and 0.35, the efficiency of the fan can be ensured, and the aerodynamic performance of the whole machine can be improved.

[0018] In an optional embodiment, from the first trailing edge portion to the first leading edge portion, the first blade top is swept in a direction consistent with the rotation direction of the axial flow fan blade and the net sweep angle gradually increases.

[0019] Beneficial effects: In this embodiment, from the first trailing edge portion to the first leading edge portion, the first blade top is swept in a direction consistent with the rotation direction of the fan blade and the net sweep angle gradually increases, which can increase the flow guiding tendency of the first blade, reduce the double-blade disturbance, and facilitate the fitting of the first blade and the second blade.

[0020] In an optional embodiment, the maximum outer edge radius of the blade unit is R, the center of the hub is taken as a base point, an axial cylindrical base circle section with a radius of r is drawn, the line connecting the center of the hub and the chord midpoint of the first blade root portion is a sixth line, the line connecting the chord midpoint of the first blade at the base circle section and the center of the hub is a seventh line, the included angle between the sixth line and the seventh line is A1, and A1 is the net sweep angle of the first blade. From the first blade root portion to the first blade top, A1 gradually increases.

[0021] Beneficial effects: From the first blade root portion to the first blade top, the net sweep angle of the first blade gradually increases, which can increase the flow guiding tendency of the first blade and reduce the double-blade disturbance.

[0022] It should be noted that A1 gradually increases from the first blade root to the first blade tip, which actually makes the seventh connecting line gradually move away from the sixth connecting line in the clockwise direction from the first blade root to the first blade tip, and thus makes the first blade tip sweep in the same direction as the wind blade from the first trailing edge to the first leading edge and the net sweep angle gradually increases.

[0023] In an alternative embodiment, 0°≤A1≤15°.

[0024] In an alternative embodiment, when r / R=0.4, A1 is 1°; when r / R=0.55, A1 is 4°; when r / R=0.7, A1 is 6°; and when r / R=0.8, A1 is 9°.

[0025] In an alternative embodiment, the first trailing edge sweeps in the same direction as the axial flow fan blade from the first blade root to the first blade tip, and the sweep angle of the first trailing edge gradually increases.

[0026] Beneficial effect: In this embodiment, because the shape of the blade trailing edge affects the working surface area of the blade surface and the pressure gradient distribution of the blade surface, when the airflow on the blade surface passes through the blade trailing edge, local pressure pulsation force is easily generated due to vortex shedding, forming vortex noise. By making the first trailing edge sweep in the same direction as the fan blade and the sweep angle of the first trailing edge gradually increase, the vortex shedding of the first trailing edge can be reduced.

[0027] In an alternative embodiment, the intersection of the first trailing edge and the outer diameter circle of the hub is a fifth point, the connecting line between the fifth point and the center of the circle is an eighth connecting line, the intersection of the base circle section and the first trailing edge is a fourth point, the tangent line of the first trailing edge at the fourth point is a first tangent line, and the included angle between the eighth connecting line and the first tangent line is A2. A2 is the sweep angle of the first trailing edge, and 0°≤A2≤55°.

[0028] In an alternative embodiment, when r / R=0.4, A2 is 9°; when r / R=0.55, A2 is 13°; when r / R=0.7, A2 is 26°; and when r / R=0.8, A2 is 41°.

[0029] Beneficial effect: In this embodiment, the vortex shedding of the first trailing edge can be reduced, and the first blade can meet the petal appearance.

[0030] In an alternative embodiment, the second blade tip sweeps in the opposite direction to the wind blade from the second trailing edge to the second leading edge, and the net sweep angle gradually increases.

[0031] Beneficial effects: in this embodiment, the second tip portion is swept in a direction opposite to the rotation direction of the wind blade from the second trailing edge portion to the second leading edge portion, and the net sweep angle gradually increases, which can increase the flow guiding tendency of the second blade, reduce the double-blade disturbance, and facilitate the fitting of the second blade and the second blade.

[0032] In an optional embodiment, the line connecting the center of the circle and the midpoint of the chord of the second blade root portion is the ninth line, the line connecting the midpoint of the chord of the second blade at the base circle section and the center of the circle is the tenth line, the included angle between the ninth line and the tenth line is A3, and A3 is the net sweep angle of the second blade. From the second blade root portion to the second blade tip portion, A3 gradually increases.

[0033] Beneficial effects: in this embodiment, the net sweep angle of the second blade gradually increases from the second blade root portion to the second blade tip portion, which can increase the flow guiding tendency of the second blade and reduce the double-blade disturbance.

[0034] It should be noted that A3 gradually increases from the second blade root portion to the second blade tip portion, which actually makes the tenth line gradually move away from the seventh line in the counterclockwise direction from the second blade root portion to the second blade tip portion, and thus the second tip portion is relatively swept in the opposite direction of the rotation direction of the wind blade from the second trailing edge portion to the second leading edge portion, and the net sweep angle gradually increases.

[0035] In an optional embodiment, -15°≤A3≤0°.

[0036] In an optional embodiment, when r / R=0.4, A3 is 0°; when r / R=0.55, A3 is -3°; when r / R=0.7, A3 is -5°; and when r / R=0.8, A3 is -7°.

[0037] In an optional embodiment, the second leading edge portion is relatively swept in the opposite direction of the rotation direction of the wind blade from the second blade root portion to the second blade tip portion, and the sweep angle of the second leading edge portion gradually increases.

[0038] Beneficial effects: the second leading edge portion is relatively swept in the opposite direction of the rotation direction of the wind blade, and the sweep angle of the second leading edge portion gradually increases, which conforms to the shape of the petal and makes the appearance more beautiful.

[0039] In an optional embodiment, the intersection of the base circle section and the second leading edge portion is the sixth point, the tangent line of the second leading edge portion at the sixth point is the second tangent line, the intersection of the second leading edge portion and the outer diameter circle of the hub is the seventh point, the line connecting the seventh point and the center of the circle is the eleventh line, the included angle between the eleventh line and the second tangent line is A4, A4 is the sweep angle of the second leading edge portion, and -55°≤A4≤0°.

[0040] Beneficial effects: in this embodiment, the sweep angle of the second leading edge portion is between -55° and 0°, which conforms to the shape of the petal and makes the appearance more beautiful.

[0041] In an alternative embodiment, when r / R=0.4, A4 is -1°; when r / R=0.55, A4 is -9°; when r / R=0.7, A4 is -19°; and when r / R=0.8, A4 is 33°.

[0042] Beneficial effect: in this embodiment, the shape of the second front edge part conforms to the modeling of the petal, and the appearance is more beautiful.

[0043] In a second aspect, the utility model also provides an air conditioning device, comprising:

[0044] The axial flow fan blade provided by the utility model in the first aspect.

[0045] The air conditioning device of the utility model in the second aspect comprises or uses the air conditioning device of the utility model in the first aspect, and therefore can achieve the beneficial effects thereof, that is, can overcome the defects in the prior art that the fan blade has large energy loss and noise during use and is prone to causing user aesthetic fatigue. BRIEF DESCRIPTION OF DRAWINGS

[0046] In order to more clearly illustrate the specific embodiments of the utility model or the technical solutions in the prior art, the drawings needed in the specific embodiments or the prior art description will be briefly introduced below, and obviously, the drawings in the following description are some embodiments of the utility model, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0047] Figure 1 It is a front view of the axial flow fan blade of the utility model embodiment;

[0048] Figure 2 It is a structural schematic diagram of the axial flow fan blade of the utility model embodiment Figure 1 ;

[0049] Figure 3 It is a structural schematic diagram of the axial flow fan blade of the utility model embodiment Figure 2 ;

[0050] Figure 4 It is a structural schematic diagram of the axial flow fan blade of the utility model embodiment Figure 3 ;

[0051] Figure 5 It is a local schematic diagram of the axial flow fan blade of the utility model embodiment Figure 1 ;

[0052] Figure 6 It is a local schematic diagram of the axial flow fan blade of the utility model embodiment Figure 2 ;

[0053] Figure 7 A partial structure diagram of the axial flow fan blade Figure 3

[0054] Figure 8 A sectional view of the first blade and the second blade on the base circle section of the axial flow fan blade

[0055] Figure 9 A partial structure diagram of the axial flow fan blade Figure 1 ;

[0056] Figure 10 A partial structure diagram of the axial flow fan blade Figure 2 ;

[0057] Figure 11 An enlarged view of A in FIG. Figure 10

[0058] Figure 12 A simulation diagram of the fan blade and the traditional fan blade.

[0059] BRIEF DESCRIPTION OF DRAWINGS

[0060] 1. first blade; 101, first blade root; 102, first blade tip; 103, first leading edge; 104, first trailing edge; 105, first suction surface; 106, first pressure surface; 107, first section;

[0061] 2. second blade; 201, second blade root; 202, second blade tip; 203, second leading edge; 204, second trailing edge; 205, second suction surface; 206, second pressure surface; 207, second section;

[0062] 3. hub; 301, air inlet end; 302, air outlet end; 4, recess; 5, connecting structure;

[0063] O, center; B1, chord midpoint of the first blade root; B2, chord midpoint of the second blade root; C1, chord midpoint of the first blade; C2, chord midpoint of the second blade;

[0064] I, first point; J, second point; Y, third point; E, fourth point; H, fifth point; G, sixth point; F, seventh point; M1, first inflection point; M2, second inflection point;

[0065] L9, first connecting line; L 11 10, second connecting line; L 12 11, third connecting line; L 10 12, fourth connecting line; L 13 ​​, a fifth connecting line; L2, a sixth connecting line; L1, a seventh connecting line; L3, an eighth connecting line; L6, a ninth connecting line; L5, a tenth connecting line; L7, an eleventh connecting line;

[0066] L4, a first tangent line; L8, a second tangent line;

[0067] b1, a first chord line; b2, a second chord line. DETAILED DESCRIPTION

[0068] To make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely described below in combination with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the utility model.

[0069] The fan in the related art adopts the traditional axial flow fan blade, the blade design thereof is usually a straight blade or a spiral blade, the traditional blade modeling is limited, there is no breakthrough in appearance for many years, which easily causes consumer aesthetic fatigue and reduces product sales; secondly, although the traditional fan blade aerodynamic design can meet the basic air supply demand, there are deficiencies in air flow efficiency, noise control and the like, the traditional fan blade design greatly influences the air flow path, vortex is easily generated at the blade tip and the blade tail edge, which leads to energy loss and noise increase; in addition, the traditional fan blade is usually a single blade design, is easily deformed and collapsed at the weak structure position of the blade tip when being formed due to the influence of material and injection molding process, changes the aerodynamic performance of the fan blade, and there are difficulties in injection molding performance error, scheme confirmation and motor matching in the product development process.

[0070] The double-blade structure in the related art includes a plurality of blades arranged on the circumferential side surface of the hub, a wind passing hole is formed on each blade or between each blade and the hub, the blade includes at least two straightening piece segments on the circumferential side of the wind passing hole, one straightening piece segment is connected to the pressure surface of the other straightening piece segment, therefore, in the direction from the leading edge of the straightening piece segment to the tail edge of the straightening piece segment, the bending directions of the two connected straightening units are opposite, the straightening effect is poor. In addition, the blade tip width of this kind of blade is relatively narrow, vortex is easily generated at the blade tip and the blade tail edge, which leads to energy loss and noise increase.

[0071] The embodiments of the utility model will be described below in combination with Figures 1 to 12 The embodiments of the utility model are described.

[0072] According to the embodiments of the utility model, on the one hand, a kind of axial flow fan blade is provided, including hub 3 and multiple blade units.

[0073] The plurality of blade units are connected to the hub 3 and are spaced along the circumference of the hub 3, and each blade unit comprises a first blade 1 and a second blade 2. The first blade 1 comprises a first blade root 101, a first blade tip 102, a first leading edge 103 and a first trailing edge 104. The second blade 2 comprises a second blade root 201, a second blade tip 202, a second leading edge 203 and a second trailing edge 204, and the second trailing edge 204 is connected to the first leading edge 103. The first blade tip 102 and the second blade tip 202 are curved and arch away from the hub 3.

[0074] The blade unit of the axial flow fan blade in the embodiment of the utility model is composed of the first blade 1 and the second blade 2, and the blade tip of each blade unit is formed in an "M" shape by fitting the first blade 1 and the second blade 2, so that the blade is closer to the petal shape, the aesthetic property of the axial flow fan blade is improved, the aesthetic fatigue of the user for the axial flow fan blade is broken, and the visual attraction of the product is increased.

[0075] On this basis, since the blade unit of the axial flow fan blade in the utility model is composed of the first blade 1 and the second blade 2, the blade tip width of the blade unit can be extended, so that the length of the airflow formed in the blade tip area is delayed, thereby reducing the scale and order of magnitude of the airflow shedding from the blade tip area, and further reducing the discrete noise generated when the axial flow fan blade rotates.

[0076] Since the blade unit of the axial flow fan blade in the utility model is formed in an "M" shape at the blade tip of each blade unit, a concave part 4 is formed at the connection position of the first blade tip 102 and the second blade tip 202, the concave part 4 can offset the airflow to a certain extent, thereby further reducing the scale and order of magnitude of the airflow shedding from the blade tip area, further reducing the vortex shedding of the blade at the blade tip and the trailing edge, and reducing the vortex noise of the blade.

[0077] Therefore, the axial flow fan blade in the utility model can overcome the defects in the related art that the fan blade has large energy loss and noise during use and is easy to cause aesthetic fatigue of the user.

[0078] In one embodiment, the first blade tip 102 and the second blade tip 202 are connected at the middle position of the blade unit.

[0079] By such an arrangement, the blade tip of each blade unit is formed in an "M" shape, so that the blade is closer to the petal shape, and the aesthetic property of the axial flow fan blade is improved.

[0080] In one embodiment, the first blade tip 102 and the second blade tip 202 are provided with a wedge-shaped connection structure 5 that is connected to the first suction surface 105 and the second suction surface 205.

[0081] In this embodiment, the first suction surface 105 and the second suction surface 205 are connected by a wedge-shaped connection structure 5, which can effectively prevent the tip of the blade from collapsing during blade forming and enhance the firmness of the blade forming.

[0082] In one specific embodiment, the curvature of the wedge-shaped connecting structure 5 is consistent with the curvature of the tip 202 of the second blade, which can reduce the influence of the wedge-shaped connecting structure 5 on the airflow.

[0083] In one embodiment, the maximum outer radius of the blade unit is R;

[0084] In one embodiment, such as Figure 6 As shown, the intersection between the top 102 of the first blade and the first trailing edge 104 is the first point I, and the distance between the first point I and the center O of the hub 3 is R', where 0.95 > R' / R > 0.75.

[0085] The intersection of the top 202 of the second leaf and the second leading edge 203 is the second point J. The distance between the second point J and the center O of the hub 3 is R', where 0.95 > R' / R > 0.75.

[0086] Using the center O of the blade hub as the base point, construct cylindrical base circle sections with different axial directions and radius r. The portion of the blade intercepted by the base circle section is the blade tip, and the axial projection curve of the base circle section with radius R' is the boundary of the blade tip. When the blade tip is in the aforementioned region, it ensures that the shape of the axial flow blade is closer to the petal shape without affecting the overall aerodynamic performance of the blade unit.

[0087] In a preferred embodiment, R' = 0.85. This ensures that the shape of the axial fan blades more closely resembles a petal shape without affecting the overall aerodynamic performance of the blade unit.

[0088] In one embodiment, the intersection between the tip 102 of the first blade and the first trailing edge is designated as point I, and the intersection between the tip 102 of the first blade and the tip 202 of the second blade is designated as point Y. Taking the center O of the hub 3 as the base point, an axial cylindrical base circle section with radius r is drawn. The line connecting the center O and the first point I is designated as the first connecting line L9, and the line connecting the center O and the third point Y is designated as the second connecting line L. 11 The first connection L9 and the second connection L 11 The included angle between them is θ1; the tip of the first blade 1 arches away from the hub 3 to form the first inflection point M1, and the line connecting the first inflection point M1 and the center O of the hub 3 is the third line L. 12 The third connection L 12 The angle between the line L9 and the first line L9 is θM1, and 0.3≤θM1 / θ1≤0.7.

[0089] θ1 is the first blade 1 of the blade top distribution angle, θM1 is the arch top distribution angle, θM1 satisfies 0.3≤θM1 / θ1≤0.7, when the curve of the first blade top 102 is distributed between 0-θM1, the blade top curve is upwardly arched in the clockwise direction of the rotation of the fan blade, when the curve of the first blade top 102 is distributed between θM1-θ1, the blade top curve of the first blade 1 is downwardly arched in the clockwise direction of the rotation of the fan blade, when 0.3≤θM1 / θ1≤0.7, an "M"-shaped petal arch shape can be formed at the blade top position of the blade unit.

[0090] The intersection between the second blade top 202 and the second leading edge 203 is a second point J, the intersection between the first blade top 102 and the second blade top 202 is a third point Y, the center O of the hub 3 is taken as a base point, an axial cylindrical base circle section with a radius r is drawn, the line connecting the center O and the second point J is a fourth line L 10 , the line connecting the center O and the third point Y is a second line L 11 , the blade top of the second blade 2 is arched away from the hub 3 and forms a second inflection point M2, the line connecting the center O and the second inflection point M2 is a fifth line L 13 , the included angle between the fifth line L 13 and the fourth line L 10 is θM2, 0.3≤θM2 / θ2≤0.7.

[0091] The second blade top 202 of the second blade 2 takes the fourth line L10 as a starting line, θM2 is the arch distribution angle of the second blade top 202, when the blade top curve of the second blade top 202 is distributed between 0-θM2, the blade top curve is upwardly arched in the counterclockwise direction of the rotation of the fan blade, when it is distributed between θM2-θ2, the blade top curve is downwardly arched in the counterclockwise direction of the rotation of the fan blade, when 0.3≤θM2 / θ2≤0.7, an "M"-shaped petal arch shape can be formed at the blade top position of the blade unit.

[0092] In this embodiment, each blade unit is composed of the first blade 1 and the second blade 2, a double-blade fitting mode is adopted, the structure of the blade unit is novel, the appearance is beautiful, the blade unit is closer to the petal shape, and the aerodynamic performance of the fan can be improved since each blade unit is composed of the first blade 1 and the second blade 2.

[0093] In a specific embodiment, the number of blade units is n, n≥3, n=5 is selected in this embodiment, so that the blade unit is closer to the petal shape.

[0094] It should be noted that the first blade 1 and the second blade 2 are arranged in the same direction of the rotation direction of the fan blade. The first blade 1 further comprises a first suction surface 105 and a first pressure surface 106. The second blade 2 comprises a second suction surface 205 and a second pressure surface 206. The axial fan blade rotates in the clockwise direction, and each blade unit is sequentially the second blade 2, the first blade 1 in the clockwise direction.

[0095] The first suction surface 105 refers to the windward side of the first blade 1, the first pressure surface 106 refers to the leeward side of the first blade 1, the second suction surface 205 refers to the windward side of the second blade 2, and the second pressure surface 206 refers to the leeward side of the second blade 2.

[0096] In one embodiment, the axial fan blade comprises a hub 3, and the blade unit is arranged on the hub 3. The outer diameter of the blade unit is D, and the diameter of the hub 3 is d, and 0.2≤d / D≤0.35.

[0097] In this embodiment, d / D refers to the hub 3 ratio, and the hub 3 ratio is an important design parameter of the axial fan. If the hub 3 ratio is too large, the efficiency of the fan will be reduced, and the aerodynamic performance of the whole machine will be reduced. On the contrary, if the hub 3 ratio of the axial fan is too small, the flow separation will occur at the blade root of the fan blade, and the performance of the fan blade will be lost. Therefore, by making the hub 3 ratio between 0.2 and 0.35, the efficiency of the fan can be ensured, and the aerodynamic performance of the whole machine can be improved.

[0098] Specifically, in one embodiment, the hub 3 ratio is 0.2.

[0099] Specifically, in one embodiment, the hub 3 ratio is 0.24.

[0100] Specifically, in one embodiment, the hub 3 ratio is 0.35.

[0101] In one embodiment, from the first trailing edge 104 to the first leading edge 103, the first tip portion 102 is swept in the same direction as the rotation direction of the fan blade, and the net sweep angle gradually increases.

[0102] In this embodiment, from the first trailing edge 104 to the first leading edge 103, the first tip portion 102 is swept in the same direction as the rotation direction of the fan blade, and the net sweep angle gradually increases, which can increase the flow guiding tendency of the first blade 1, reduce the double blade disturbance, and facilitate the fitting of the first blade 1 and the second blade 2.

[0103] In one embodiment, the maximum outer edge radius of the blade unit is R, and an axial cylindrical base circle section with a radius of r is made with the center O of the hub 3 as the base point, the line connecting the center O and the chord midpoint B1 of the first blade root is the sixth line L2, the line connecting the chord midpoint C1 of the first blade at the base circle section and the center O is the seventh line L1, the included angle between the sixth line L2 and the seventh line L1 is A1, A1 is the net bending angle of the first blade 1, which gradually increases from the first blade root 101 to the first blade tip 102.

[0104] In this embodiment, the net bending angle of the first blade 1 gradually increases from the first blade root 101 to the first blade tip 102, which can increase the flow guiding tendency of the first blade 1 and reduce the double-blade disturbance effect.

[0105] It should be noted that A1 gradually increases from the first blade root 101 to the first blade tip 102, which actually makes the seventh line L1 gradually move away from the sixth line L2 in the clockwise direction from the first blade root 101 to the first blade tip 102, so that the first blade tip 102 bends and sweeps in the same direction as the wind blade from the first trailing edge 104 to the first leading edge 103, and the net bending angle gradually increases.

[0106] In one embodiment, 0°≤A1≤15°.

[0107] In one embodiment, when r / R=0.4, A1 is 1°; when r / R=0.55, A1 is 4°; when r / R=0.7, A1 is 6°; and when r / R=0.8, A1 is 9°.

[0108] In one embodiment, the first trailing edge 104 bends and sweeps in the same direction as the wind blade from the first blade root 101 to the first blade tip 102, and the bending angle of the first trailing edge 104 gradually increases.

[0109] In this embodiment, since the shape of the blade trailing edge affects the blade surface working area and the pressure gradient distribution on the blade surface, when the airflow on the blade surface passes through the blade trailing edge, local pressure pulsation force is easily generated due to the vortex shedding of the trailing vortex, forming vortex noise. By making the first trailing edge 104 bend and sweep in the same direction as the wind blade and the bending angle of the first trailing edge 104 gradually increase, the vortex shedding of the first trailing edge 104 can be reduced.

[0110] In one embodiment, the intersection of the first trailing edge 104 and the outer diameter circle of the hub 3 is the fifth point H, the line connecting the fifth point H and the center O is the eighth line L3, the intersection of the base circle section and the first trailing edge 104 is the fourth point E, the tangent line of the first trailing edge 104 at the fourth point E is the first tangent line L4, the included angle between the eighth line L3 and the first tangent line L4 is A2, A2 is the bending angle of the first trailing edge 104, and 0°≤A2≤55°.

[0111] In this embodiment, by setting 0°≤A2≤55°, the vortex shedding of the first trailing edge portion 104 can be reduced, and the first blade 1 can satisfy the petal appearance.

[0112] In one embodiment, A2 is 9° when r / R=0.4; A2 is 13° when r / R=0.55; A2 is 26° when r / R=0.7; and A2 is 41° when r / R=0.8.

[0113] In this embodiment, the vortex shedding of the first trailing edge portion 104 can be reduced, and the first blade 1 can satisfy the petal appearance.

[0114] In one embodiment, the second tip portion 202 is swept in a direction opposite to the rotation direction of the wind blade from the second trailing edge portion 204 to the second leading edge portion 203, and the net sweep angle gradually increases.

[0115] In this embodiment, the second tip portion 202 is swept in a direction opposite to the rotation direction of the wind blade from the second trailing edge portion 204 to the second leading edge portion 203, and the net sweep angle gradually increases, which can increase the flow guiding tendency of the second blade 2, reduce the double-blade disturbance, and facilitate the fitting of the second blade 2.

[0116] In one embodiment, the line connecting the center O and the midpoint B2 of the chord of the second blade root portion is the ninth line L6, the line connecting the center O and the midpoint C2 of the chord of the second blade at the base circle section is the tenth line L5, the included angle between the ninth line L6 and the tenth line L5 is A3, and A3 is the net sweep angle of the second blade 2, which gradually increases from the second blade root portion 201 to the second tip portion 202.

[0117] In this embodiment, the net sweep angle of the second blade 2 gradually increases from the second blade root portion 201 to the second tip portion 202, which can increase the flow guiding tendency of the second blade 2 and reduce the double-blade disturbance.

[0118] It should be noted that A3 gradually increases from the second blade root portion 201 to the second tip portion 202, which actually makes the tenth line L5 gradually move away from the seventh line L1 in the counterclockwise direction from the second blade root portion 201 to the second tip portion 202, and thus the second tip portion 202 is swept in a direction opposite to the rotation direction of the wind blade from the second trailing edge portion 204 to the second leading edge portion 203, and the net sweep angle gradually increases.

[0119] In one embodiment, -15°≤A3≤0°.

[0120] It should be noted that A3 being negative means that the tenth line L5 is located on the counterclockwise side of the ninth line L6, and in combination with Figure 7 , the tenth line L5 is located on the left side of the ninth line L6.

[0121] In one embodiment, A3 is 0° when r / R=0.4; A3 is -3° when r / R=0.55; A3 is -5° when r / R=0.7; and A3 is -7° when r / R=0.8.

[0122] In one embodiment, the second leading edge portion 203 is curved and swept in a direction opposite to the rotation direction of the fan blade from the second blade root portion 201 to the second blade tip portion 202, and the angle of the second leading edge portion 203 is gradually increased.

[0123] In this embodiment, the second leading edge portion 203 is curved and swept in a direction opposite to the rotation direction of the fan blade, and the angle of the second leading edge portion 203 is gradually increased, which conforms to the shape of a petal and makes the appearance more beautiful.

[0124] In one embodiment, the intersection of the base circle section and the second leading edge portion 203 is a sixth point G, the tangent line of the second leading edge portion 203 at the sixth point G is a second tangent line L8, the intersection of the second leading edge portion 203 and the outer diameter circle of the hub 3 is a seventh point F, the line connecting the seventh point F and the center O is an eleventh line L7, the included angle between the eleventh line L7 and the second tangent line L8 is A4, A4 is the angle of the second leading edge portion 203, and -55°≤A4≤0°.

[0125] In this embodiment, the angle of the second leading edge portion 203 is between -55° and 0°, which conforms to the shape of a petal and makes the appearance more beautiful.

[0126] It should be noted that the negative value of A4 represents that the second tangent line L8 is located on the side opposite to the eleventh line L7 in the counterclockwise direction, and in combination with Figure 7 , the second tangent line L8 is located on the left side of the eleventh line L7.

[0127] In one embodiment, A4 is -1° when r / R=0.4; A4 is -9° when r / R=0.55; A4 is -19° when r / R=0.7; and A4 is -33° when r / R=0.8.

[0128] In this embodiment, the shape of the second leading edge portion 203 conforms to the shape of a petal and makes the appearance more beautiful.

[0129] In one embodiment, the first leading edge portion 103 is curved and swept in the same direction as the rotation direction of the fan blade from the first blade root portion 101 to the first blade tip portion 102, and the angle of the first leading edge portion 103 is gradually increased.

[0130] In this embodiment, since the first blade 1 is located behind the second blade 2 when the axial flow fan blade rotates in the clockwise direction, the air flow on the blade surface of the first blade 1 is more or less affected by the second trailing edge 204, thereby affecting the working efficiency of the first blade 1. Therefore, the first leading edge 103 is swept in the same direction as the rotation direction of the fan blade, and the sweep angle of the first leading edge 103 gradually increases, which can increase the flow guiding tendency of the first blade 1 and reduce the double-blade turbulence effect.

[0131] In this embodiment, by setting the sweep angle of the first leading edge 103 to be between 0° and 10°, the fitting of the first blade 1 and the second blade 2 is facilitated.

[0132] In one embodiment, when r / R=0.4, A5 is 4°; when r / R=0.55, A5 is 5°; when r / R=0.7, A5 is 6°; when r / R=0.85, A5 is 7°; and when r / R=0.95, A5 is 9°.

[0133] In one embodiment, on the base circle section, the cross section of the first blade 1 is the first cross section 107, and the cross section of the second blade 2 is the second cross section 207. From the first trailing edge 104 to the first leading edge 103, the first cross section 107 is swept in the same direction as the rotation direction of the fan blade. From the second trailing edge 204 to the second leading edge 203, the second cross section 207 is swept in the same direction as the rotation direction of the fan blade.

[0134] In this embodiment, by sweeping the first cross section 107 in the same direction as the rotation direction of the fan blade from the first trailing edge 104 to the first leading edge 103, and sweeping the second cross section 207 in the same direction as the rotation direction of the fan blade from the second trailing edge 204 to the second leading edge 203, the flow guiding tendency can be increased, and the air flow can be smoother.

[0135] In one embodiment, on the first cross section 107, the line connecting the first leading edge 103 and the first trailing edge 104 is the first chord line b1, and the included angle between the first chord line b1 and the inlet end 301 end surface of the hub 3 is Q1. On the second cross section 207, the line connecting the second leading edge 203 and the second trailing edge 204 is the second chord line b2, and the included angle between the second chord line b2 and the inlet end 301 end surface of the hub 3 is Q2.

[0136] When r / R=0.4, 35°≤Q1≤45°, and 35°≤Q2≤45°;

[0137] When r / R=0.55, 30°≤Q1≤35°, and 30°≤Q2≤40°;

[0138] When r / R=0.7, 25°≤Q1≤30°, and 25°≤Q2≤35°;

[0139] When r / R=0.85, 20°≤Q1≤30°, and 20°≤Q2≤30°;

[0140] r / R = 0.98, 15° ≤ Q1 ≤ 25°, 0° ≤ Q2 ≤ 10°.

[0141] Specifically, in one embodiment, r / R = 0.4, Q1 = 36.2°, Q2 ≤ 36.2°;

[0142] r / R = 0.55, Q1 = 30.6°, Q2 ≤ 33.5°;

[0143] r / R = 0.7, Q1 = 26.8°, Q2 ≤ 29.9°;

[0144] r / R = 0.85, Q1 = 23.7°, Q2 ≤ 23.3°;

[0145] r / R = 0.98, Q1 = 20.4°, Q2 ≤ 7°.

[0146] In one embodiment, the first leading edge portion 103 is concave to the side where the air inlet end 301 of the hub 3 is located, the second trailing edge portion 204 is arched to the side where the air outlet end 302 of the hub 3 is located, and the first blade tip portion 102 is connected to the second blade tip portion 202.

[0147] In this embodiment, by making the first leading edge portion 103 concave to the side where the air inlet end 301 of the hub 3 is located, the second trailing edge portion 204 arched to the side where the air outlet end 302 of the hub 3 is located, and the first blade tip portion 102 connected to the second blade tip portion 202, as shown in Figure 8 the direction from the leading edge to the trailing edge, the bending directions of the first blade 1 and the second blade 2 of the present application are the same, which can make the first blade 1 and the second blade 2 have sufficient flow area between them, making the airflow flow more smoothly between the double blades, improving the aerodynamic performance and flow guiding effect of the blades, and at the same time, facilitating the transition and fitting of the petal-shaped modeling of the double blade tips.

[0148] In one embodiment, the first trailing edge portion 104, the first blade tip portion 102, the second leading edge portion 203, and the second blade tip portion 202 are provided with rounded corners, and along the rotation direction of the fan blade, the first blade 1 is curved to the side where the air inlet end 301 of the hub 3 is located from the first trailing edge portion 104 to the first blade tip portion 102, curved to the side where the air outlet end 302 of the hub 3 is located from the first blade tip portion 102 to the first leading edge portion 103, the second blade 2 is curved to the side where the air inlet end 301 of the hub 3 is located from the second trailing edge portion 204 to the second blade tip portion 202, and curved to the side where the air outlet end 302 of the hub 3 is located from the second blade tip portion 202 to the second leading edge portion 203.

[0149] In this embodiment, the shape of the blade unit is more in line with the modeling of the petals, and the appearance is more beautiful.

[0150] In one embodiment, the first blade tip 102 and the second blade tip 202 form a concave portion 4 at the joint.

[0151] In this embodiment, the first blade tip 102 and the second blade tip 202 form a concave portion 4 at the joint, and the shape of the blade unit is more in line with the shape of a petal, and the appearance is more beautiful.

[0152] In combination Figure 12 , the axial flow fan blade provided by the embodiment can effectively reduce vortex shedding at the blade tip and the trailing edge of the blade compared with the conventional fan blade, thereby reducing vortex noise of the blade, and can effectively improve aerodynamic loss caused by airflow separation on the blade surface, and improve the air volume performance of the fan blade.

[0153] Blade arrangement Air volume (m3 / min) Noise (dB) Conventional blade 41 61 Blade of the present embodiment 47 59.3

[0154] According to the embodiment of the utility model, on the other hand, an air conditioning device is also provided, which comprises the axial flow fan blade provided in the above embodiment.

[0155] The air conditioning device of the second aspect of the utility model comprises or uses the air conditioning device of the first aspect of the utility model, and therefore can achieve the beneficial effects thereof, i.e., can overcome the defects in the related art that the fan blade has large energy loss and noise during use and is prone to causing user aesthetic fatigue.

[0156] Although the embodiments of the utility model are described in combination with the drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the utility model, and such modifications and variations all fall within the scope of the utility model claimed.

Claims

1. An axial flow fan blade, characterized in that, include: Wheel hub (3); Multiple blade units are connected to the hub (3) and distributed circumferentially along the hub (3). Each blade unit includes a first blade (1) and a second blade (2). The first leaf (1) includes a first leaf root (101), a first leaf tip (102), a first leading edge (103) and a first trailing edge (104); The second blade (2) includes a second blade root (201), a second blade tip (202), a second leading edge (203) and a second trailing edge (204), the second trailing edge (204) being connected to the first leading edge (103), the first blade tip (102) and the second blade tip (202) being arched and arching away from the hub (3).

2. The axial flow fan blade according to claim 1, characterized in that, The first leaf tip (102) and the second leaf tip (202) are connected at the middle position of the blade unit.

3. The axial flow fan blade according to claim 1, characterized in that, The maximum outer radius of the blade unit is R; The intersection point between the tip (102) of the first blade and the first trailing edge (104) is the first point (I), and the distance between the first point (I) and the center (O) of the hub (3) is R', where 0.95 > R' / R > 0.75; and / or, The intersection between the tip (202) of the second blade and the second leading edge (203) is the second point (J), and the distance between the second point (J) and the center (O) of the hub (3) is R', 0.95 > R' / R > 0.

75.

4. The axial flow fan blade according to claim 2, characterized in that, The intersection between the tip of the first blade (102) and the first trailing edge is the first point (I), and the intersection between the tip of the first blade (102) and the tip of the second blade (202) is the third point (Y). Taking the center (O) of the hub (3) as the base point, an axial cylindrical base circle section with radius r is drawn. The line connecting the center (O) and the first point (I) is the first connecting line (L9), and the line connecting the center (O) and the third point (Y) is the second connecting line (L). 11 The first connection (L9) and the second connection (L) 11 The included angle between the first blade (1) and the hub (3) is θ1; the tip of the first blade (1) arches away from the hub (3) to form a first inflection point (M1), and the line connecting the first inflection point (M1) and the center (O) of the hub (3) is the third line (L). 12 The third connection (L) 12 The angle between the line (L9) and the first line is θM1, and 0.3≤θM1 / θ1≤0.

7.

5. The axial flow fan blade according to claim 2, characterized in that, The intersection between the tip (202) of the second blade and the second leading edge (203) is the second point (J), and the intersection between the tip (102) of the first blade and the tip (202) of the second blade is the third point (Y). Taking the center (O) of the hub (3) as the base point, an axial cylindrical base circle section with radius r is drawn. The line connecting the center (O) and the second point (J) is the fourth line (L). 10 The line connecting the center (O) and the third point (Y) is the second line (L). 11 The tip of the second blade (2) arches away from the hub (3) and forms a second inflection point (M2). The line connecting the center (O) and the second inflection point (M2) is the fifth line (L). 13 The fifth connection (L) 13 ) and the fourth connection (L) 10 The angle between them is θM2, and 0.3≤θM2 / θ2≤0.

7.

6. The axial flow fan blade according to any one of claims 1 to 5, characterized in that, The outer diameter of the blade unit is D, and the diameter of the hub (3) is d, 0.2≤d / D≤0.

35.

7. The axial flow fan blade according to claim 6, characterized in that, From the first trailing edge (104) to the first leading edge (103), the tip of the first blade (102) bends in a direction consistent with the rotation direction of the axial flow blade and the net bending angle gradually increases.

8. The axial flow fan blade according to claim 6, characterized in that, The maximum outer radius of the blade unit is R. Taking the center (O) of the hub (3) as the base point, an axial cylindrical base circle section with radius r is drawn. The line connecting the center (O) and the midpoint (B1) of the chord at the root of the first blade is the sixth line (L2). The line connecting the midpoint (C1) of the chord of the first blade at the base circle section and the center (O) is the seventh line (L1). The angle between the sixth line (L2) and the seventh line (L1) is A1. A1 is the net bending angle of the first blade (1). From the root (101) of the first blade to the tip (102) of the first blade, A1 gradually increases.

9. The axial flow fan blade according to claim 6, characterized in that, 0°≤A1≤15°。 10. The axial flow fan blade according to claim 6, characterized in that, When r / R = 0.4, A1 is 1°; when r / R = 0.55, A1 is 4°; when r / R = 0.7, A1 is 6°; when r / R = 0.8, A1 is 9°.

11. The axial flow fan blade according to claim 8, characterized in that, From the root (101) of the first blade to the tip (102) of the first blade, the first trailing edge (104) bends in a direction consistent with the rotation direction of the axial flow blade, and the bend angle of the first trailing edge (104) gradually increases.

12. The axial flow fan blade according to claim 11, characterized in that, The intersection of the first trailing edge (104) and the outer diameter circle of the hub (3) is the fifth point (H). The line connecting the fifth point (H) and the center (O) of the circle is the eighth line (L3). Taking the center (O) of the hub (3) as the base point, an axial cylindrical base circle section with radius r is drawn. The intersection of the base circle section and the first trailing edge (104) is the fourth point (E). The tangent of the first trailing edge (104) at the fourth point (E) is the first tangent (L4). The angle between the eighth line (L3) and the first tangent (L4) is A2. A2 is the sweep angle of the first trailing edge (104), 0°≤A2≤55°.

13. The axial flow fan blade according to claim 12, characterized in that, When r / R = 0.4, A2 is 9°; when r / R = 0.55, A2 is 13°; when r / R = 0.7, A2 is 26°; when r / R = 0.8, A2 is 41°.

14. The axial flow fan blade according to any one of claims 1 to 5, characterized in that, From the second trailing edge (204) to the second leading edge (203), the tip of the second blade (202) bends in the opposite direction to the blade rotation, and the net bending angle gradually increases.

15. The axial flow fan blade according to claim 14, characterized in that, Taking the center (O) of the hub (3) as the base point, draw an axial cylindrical base circle section with radius r. The line connecting the center (O) and the midpoint (B2) of the chord at the root of the second blade is the ninth line (L6). The line connecting the midpoint (C2) of the chord of the second blade at the base circle section and the center (O) is the tenth line (L5). The angle between the ninth line (L6) and the tenth line (L5) is A3. A3 is the net bending angle of the second blade (2). From the root (201) of the second blade to the top (202) of the second blade, A3 gradually increases.

16. The axial flow fan blade according to claim 15, characterized in that, -15°≤A3≤0°。 17. The axial flow fan blade according to claim 15, characterized in that, When r / R = 0.4, A3 is 0°; when r / R = 0.55, A3 is -3°; when r / R = 0.7, A3 is -5°; when r / R = 0.8, A3 is -7°.

18. The axial flow fan blade according to any one of claims 1 to 5, characterized in that, From the root (201) of the second blade to the tip (202) of the second blade, the second leading edge (203) sweeps against the direction of the blade rotation and the sweep angle of the second leading edge (203) gradually increases.

19. The axial flow fan blade according to claim 18, characterized in that, Taking the center (O) of the hub (3) as the base point, draw an axial cylindrical base circle section with radius r. The intersection of the base circle section and the second leading edge (203) is the sixth point (G). The tangent of the second leading edge (203) at the sixth point (G) is the second tangent (L8). The intersection of the second leading edge (203) and the outer diameter circle of the hub (3) is the seventh point (F). The line connecting the seventh point (F) and the center (O) is the eleventh line (L7). The angle between the eleventh line (L7) and the second tangent (L8) is A4. A4 is the sweep angle of the second leading edge (203), -55°≤A4≤0°.

20. The axial flow fan blade according to claim 19, characterized in that, When r / R = 0.4, A4 is -1°; when r / R = 0.55, A4 is -9°; when r / R = 0.7, A4 is -19°; when r / R = 0.8, A4 is 33°.

21. An air conditioning device, characterized in that, include: The axial flow fan blade according to any one of claims 1 to 20.

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