Air outlet grille, axial flow fan and household appliance

Abstract

The utility model relates to the technical field of axial flow fans, in particular to an air outlet grille, an axial flow fan and a household appliance. The air outlet grille aims at solving the problems that air flow resistance can be increased by the air outlet grille in the related technology, air volume loss of the axial flow fan is serious, and noise is increased. Therefore, the air outlet grille comprises a grille body provided with a fixing area extending in the circumferential direction of the grille body; the multiple flow guide ribs are arranged in the fixed area at intervals in the circumferential direction of the grille body; wherein the inclination angle of the flow guide rib and the air inlet direction of the air outlet grid form a preset angle, the upper surface of the flow guide rib is a concave arc-shaped surface, the flow guide rib comprises a windward end face and a leeward end face, the thickness of the flow guide rib is gradually increased from the windward end face to the leeward end face, and the flow guide rib is gradually narrowed at the leeward end face. According to the air outlet grille, the air outlet flow direction of the fan blades can be well guided, the resistance of the air outlet grille to airflow is reduced, and therefore the air volume loss and noise are reduced.

Description

Technical Field

[0001] The present application relates to the technical field of axial fans, and particularly to an air outlet grille, an axial fan and a household appliance device. Background Art

[0002] At present, most of the axial fans of household appliance devices are provided with air outlet grilles. For example, the axial fan of an air conditioner outdoor unit is provided with an air outlet grille. After the fan blades of the axial fan rotate to drive the air flow to flow through the outdoor heat exchanger of the air conditioner outdoor unit, the air flows out of the air conditioner outdoor unit through the air outlet grille.

[0003] The air outlet grille in the related art is mainly for enhancing safety and preventing users from contacting the high-speed rotating fan blades. However, the air outlet grille in the related art will increase the resistance of the air flow, resulting in serious air volume loss and increased noise of the axial fan, which affects the user experience.

[0004] Correspondingly, a new technical solution is needed in this field to solve the above problems. Summary of the Utility Model

[0005] In order to solve at least one of the above problems in the prior art, that is, to solve the problem that the air outlet grille in the related art increases the resistance of the air flow, resulting in serious air volume loss and increased noise of the axial fan.

[0006] In a first aspect, the present application provides an air outlet grille, which includes: a grille body provided with a fixed area extending along the circumferential direction of the grille body; a plurality of guide ribs arranged at intervals along the circumferential direction of the grille body in the fixed area; wherein, the inclination angle of the guide rib forms a preset angle with the air inlet direction of the air outlet grille, the upper surface of the guide rib is a concave arc surface, the guide rib includes a windward end face and a leeward end face, and along the windward end face to the leeward end face, the thickness of the guide rib gradually increases and gradually narrows at the leeward end face.

[0007] In some embodiments, both the windward end face and the leeward end face of the guide rib are convex arc surfaces, and the radius of the arc corresponding to the windward end face is smaller than the radius of the arc corresponding to the leeward end face.

[0008] In some embodiments, the guide rib includes a strip-shaped cross-section perpendicular to the length direction of the guide rib; the strip-shaped cross-section includes a windward leading edge, a maximum thickness position, and a gradually thickening section located between the windward leading edge and the maximum thickness position; wherein, the length of the positive projection of the gradually thickening section in the axial direction of the air outlet grille is L1, the length of the positive projection of the strip-shaped cross-section in the axial direction is L2, and L1 / L2=(0.5-1).

[0009] In some embodiments, the maximum thickness of the bar-shaped cross-section is B1, and B1 / L2 = (0.2 to 0.5); and / or, the bar-shaped cross-section includes a first curve on the windward side and an upper curve connected to the first curve; the tangent at the connection of the first curve and the upper curve is the first tangent, and the range of the angle between the first tangent and the air inlet direction is [-10°, 10°]; and / or, the bar-shaped cross-section includes a second curve near the leeward side, the tangent at the connection of the second curve and the upper curve is the second tangent, and the range of the angle between the second tangent and the axial direction is 0° to 10°.

[0010] In some embodiments, the bar-shaped cross-section includes a lower profile line, and the lower profile line is a straight line or a convex curve.

[0011] In some embodiments, the center of the air outlet grille protrudes towards the leeward side; or, the center of the air outlet grille protrudes towards the leeward side, and the range of the angle between the radial direction of the air outlet grille and the vertical direction is 1° to 5°.

[0012] In some embodiments, the grille body includes a central disc, an outer frame, and a plurality of annular ribs with different inner diameters arranged between the outer frame and the central disc. The plurality of annular ribs are concentric with the outer frame. Among them, the fixed areas are defined between the central disc and the annular ribs, between adjacent annular ribs, and between the annular ribs and the outer frame.

[0013] In some embodiments, the outer frame is set to be circular or square; and / or, the annular ribs are set to be circular, square, or semi-enclosed; and / or, the air outlet grille is set to be a plane or an arc surface; and / or, fixing holes and buckles are provided on the outer frame.

[0014] In a second aspect, the present application provides an axial flow fan, which includes an axial flow fan and the above-mentioned air outlet grille, and the air outlet grille is arranged on the air outlet side of the axial flow fan.

[0015] In a third aspect, the present application provides a household electrical appliance, which includes an axial flow fan and the above-mentioned air outlet grille, and the air outlet grille is arranged on the air outlet side of the axial flow fan.

[0016] The air inlet direction of the air outlet grille is the air outlet direction of the fan blades of the axial flow fan. The inclination angle of the flow guiding ribs of the air outlet grille forms a preset angle with the air inlet direction of the air outlet grille, which can make the flow guiding ribs adapt to the angle of the fan blade air outlet and reduce the resistance of the flow guiding ribs to the fan blade air outlet. The upper surface of the flow guiding rib is a concave arc surface, which can better guide the flow direction of the air flow. Along the windward end face of the flow guiding rib to the leeward end face of the flow guiding rib, the thickness of the flow guiding rib gradually increases, that is, the thickness of the windward end face is smaller. In this way, not only can the resistance to the fan blade air outlet be further reduced to maximize the effective air inlet area of the air outlet grille, but also the angle of the fan blade air outlet can be better adapted, and the air flow can be guided to the flow guiding rib more smoothly. The thickness of the flow guiding rib near the leeward end face is larger and gradually narrows at the leeward end face, which can guide the flow direction of the air flow, make the air flow flow out smoothly, and thus reduce the trailing edge shedding vortex. In addition, the larger thickness of the leeward end face can prevent users from inserting fingers or foreign objects into the axial flow fan, which is beneficial to improving the safety of the axial flow fan. On the premise of adopting the above technical solution, the air outlet grille provided by this application can better guide the flow direction of the fan blade air outlet, reduce the resistance of the air outlet grille to the air flow, and thus reduce the air volume loss and noise. Brief Description of the Drawings

[0017] The air outlet grille, battery pack, locking mechanism and vehicle of this application will be described below with reference to the drawings. In the drawings:

[0018] Figure 1 is a schematic structural diagram of the air outlet grille of this application;

[0019] Figure 2 is a schematic structural diagram of the flow guiding rib of this application;

[0020] Figure 3 is Figure 1 a partial enlarged structural diagram of the air outlet grille in

[0021] Figure 4 is Figure 3 the structural diagram of section B-B in

[0022] Figure 5 is Figure 1 a side view of the air outlet grille in

[0023] Figure 6 is another schematic structural diagram of the air outlet grille of this application;

[0024] Figure 7 is another schematic structural diagram of the air outlet grille of this application;

[0025] Figure 8 is another schematic structural diagram of the air outlet grille of this application;

[0026] Figure 9 isFigure 1 Structural schematic diagram of the air outlet grille from another perspective.

[0027] List of Reference Numerals

[0028] 100, grille body; 101, fixed area; 102, central disc; 103, outer frame; 104, annular rib; 200, guide rib; 201, windward end face; 202, leeward end face; 203, strip cross-section; 2031, windward leading edge; 2032, maximum thickness position; 2033, thickening section; 2034, first curve; 2035, upper curve; 2036, second curve; 2037, lower profile. Specific embodiments

[0029] The preferred embodiments of the present application will be described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principle of the present application and are not intended to limit the protection scope of the present application. For example, although the following embodiments of the present application are described in conjunction with the outdoor unit of an air conditioner, this is not intended to limit the protection scope of the present application. Without departing from the principle of the present application, the air outlet grille and the axial flow fan of the present application can also be applied to other household electrical appliances.

[0030] It should be noted that in the description of the present application, the terms indicating directions or positional relationships such as "middle", "upper", "lower", "vertical", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings. This is only for convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present application. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. "Plural" means two or more.

[0031] In addition, it should also be noted that in the description of the present application, unless otherwise clearly specified and limited, the terms "installation", "connection", and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those skilled in the art, the specific meanings of the above terms in the present application can be understood according to specific situations.

[0032] Currently, most of the axial flow fans of household electrical appliances are equipped with air outlet grilles. For example, the axial flow fan of the outdoor unit of an air conditioner is provided with an air outlet grille. After the fan blades of the axial flow fan rotate to drive the air flow to flow through the outdoor heat exchanger of the outdoor unit of the air conditioner, the air flows out of the outdoor unit of the air conditioner through the air outlet grille.

[0033] The air outlet grille in the related art is mainly for enhancing safety and preventing users from coming into contact with the high-speed rotating fan blades. However, the air outlet grille in the related art increases the resistance of the air flow, resulting in serious loss of air volume of the axial flow fan and increased noise, which affects the user experience.

[0034] In order to reduce the resistance of the air outlet grille to the air flow and lower the noise, the present application provides an air outlet grille, an axial flow fan, and a household electrical appliance.

[0035] In the first aspect, the present application provides an air outlet grille.

[0036] Combined with Figure 1 and Figure 2 as shown, the air outlet grille provided by the present application includes a grille body 100 and a plurality of flow guiding ribs 200.

[0037] The grille body 100 is provided with a fixed area 101 extending along the circumferential direction of the grille body 100. The plurality of flow guiding ribs 200 are arranged at intervals along the circumferential direction of the grille body 100 in the fixed area 101.

[0038] Wherein, the inclination angle of the flow guiding rib 200 forms a preset angle with the air inlet direction of the air outlet grille. The upper surface of the flow guiding rib 200 is a concave arc surface. The flow guiding rib 200 includes a windward end face 201 and a leeward end face 202. Along the windward end face 201 to the leeward end face 202, the thickness of the flow guiding rib 200 gradually increases and gradually narrows at the leeward end face 202.

[0039] The air inlet direction of the air outlet grille is the air outlet direction of the fan blades of the axial flow fan. The inclination angle of the flow guiding rib 200 of the air outlet grille forms a preset angle with the air inlet direction of the air outlet grille, which can make the flow guiding rib 200 adapt to the angle of the fan blade air outlet and reduce the resistance of the flow guiding rib 200 to the fan blade air outlet. The upper surface of the flow guiding rib 200 is a concave arc surface, which can better guide the flow direction of the air flow. Along the windward end face 201 of the flow guiding rib 200 to the leeward end face 202 of the flow guiding rib 200, the thickness of the flow guiding rib 200 gradually increases, that is, the thickness of the windward end face 201 is smaller. In this way, not only can the resistance to the fan blade air outlet be further reduced to maximize the effective air inlet area of the air outlet grille, but also the angle of the fan blade air outlet can be better adapted, and the air flow can be more smoothly guided to the flow guiding rib 200. The thickness of the flow guiding rib 200 near the leeward end face 202 is larger and gradually narrows at the leeward end face 202, which can guide the flow direction of the air flow, making the air flow flow out smoothly, thereby reducing the trailing edge shedding vortex. In addition, the larger thickness of the leeward end face 202 can prevent users from inserting fingers or foreign objects into the axial flow fan, which is beneficial to improving the safety of the axial flow fan. On the premise of adopting the above technical solutions, the air outlet grille provided by the present application can better guide the flow direction of the fan blade air outlet, reduce the resistance of the air outlet grille to the air flow, thereby reducing the air volume loss and noise.

[0040] In some embodiments, in combination with Figure 2 As shown, both the windward end face 201 and the leeward end face 202 of the flow guiding rib 200 are outwardly convex arc surfaces, and the radius of the arc corresponding to the windward end face 201 is smaller than the radius of the arc corresponding to the leeward end face 202.

[0041] After the air flow contacts the arc-shaped windward end face 201, it starts to split, and the separated air flow flows along the arc surface to the upper and lower sides of the flow guiding rib 200 under the action of the wall attachment effect. By designing the windward end face 201 as an outwardly convex arc surface, the air flow can be better guided. By designing the leeward end face 202 as an outwardly convex arc surface, it is beneficial to improve safety and prevent the user from being scratched when contacting the air outlet grille. The radius of the arc corresponding to the windward end face 201 is smaller than the radius of the arc corresponding to the leeward end face 202, and the flow guiding rib 200 has a structure with a thin windward end face 201 and a thick leeward end face 202. The thin windward end face 201 can adapt to various air outlet angles and reduce the resistance to the air flow, while the thick leeward end face 202 can prevent the user from inserting a finger into the air outlet grille and pass the safety finger test.

[0042] In some embodiments, in combination with Figure 3 and Figure 4 As shown, the flow guiding rib 200 includes a strip-shaped cross-section 203 perpendicular to the length direction of the flow guiding rib 200. The strip-shaped cross-section 203 includes a windward leading edge 2031, a maximum thickness position 2032, and a gradually thickening section 2033 located between the windward leading edge 2031 and the maximum thickness position 2032. Among them, the length of the positive projection of the gradually thickening section 2033 in the axial direction of the air outlet grille is L1, and the length of the positive projection of the strip-shaped cross-section 203 in the axial direction is L2, and L1 / L2 = (0.5 - 1).

[0043] By limiting the ratio of L1 and L2 within the above range, the thickness of the flow guiding rib 200 can show a trend of gradually increasing from the windward end face to the leeward end face and gradually narrowing at the leeward end face, reducing the resistance to the air flow and at the same time reducing the trailing edge shedding vortex. If the maximum thickness position 2032 is too close to the windward end of the strip-shaped cross-section 203, it will cause serious wind blocking and excessive wind resistance. If the maximum thickness position 2032 is too close to the leeward end of the strip-shaped cross-section 203, it will cause a relatively large trailing edge shedding vortex. For example, L1 / L2 = 0.5, 0.6, 0.7, 0.8, 0.9 or 1, etc.

[0044] In some embodiments, the maximum thickness of the strip-shaped cross-section 203 is B1, and B1 / L2 = (0.2 - 0.5). By limiting the maximum thickness B1 of the strip-shaped cross-section 203 and the length L2 of the positive projection of the strip-shaped cross-section 203 in the axial direction within the above range, it is beneficial to reduce the air volume loss and noise.

[0045] For example, B1 / L2 = 0.2, 0.3, 0.4, or 0.5, etc.

[0046] In some embodiments, as shown in Figure 4 the bar-shaped cross-section 203 includes a first curve 2034 on the windward side and an upper curve 2035 connected to the first curve 2034. The tangent at the connection of the first curve 2034 and the upper curve 2035 is the first tangent line l1, and the value range of the angle α1 between the first tangent line l1 and the air inlet direction is [-10°, 10°]. Such a setting can make the windward end face of the flow guiding rib 200 as parallel as possible to the air inlet direction of the air outlet grille, reducing the resistance of the air outlet grille to the air flow.

[0047] For example, the value of the angle α1 between the first tangent line l1 and the air inlet direction is -10°, -7°, -5°, -3°, -1°, -0°, 2°, 5°, 6°, -8°, or 10°, etc.

[0048] In some embodiments, as shown in Figure 4 the bar-shaped cross-section 203 includes a second curve 2036 near the leeward side. The tangent at the connection of the second curve 2036 and the upper curve 2035 is the second tangent line l2, and the value range of the angle α2 between the second tangent line l2 and the axial direction is 0° to 10°. By limiting the angle α2 between the second tangent line l2 and the axial direction within the above range, it is beneficial to make the air flow out along the axial direction of the air outlet grille, reducing the trailing edge shedding vortex.

[0049] In some embodiments, as shown in Figure 4 the bar-shaped cross-section 203 includes a lower profile line 2037, and the lower profile line 2037 is a straight line or a convex curve. By setting the lower profile line 2037 as a straight line or a convex curve, the air conditioner ensures that the air flow along the lower profile line 2037 and does not separate from the flow guiding rib 200.

[0050] In some embodiments, as shown in Figure 1 and Figure 5 the center of the air outlet grille protrudes toward the leeward side. By setting the air outlet grille as a convex shape, the strength of the air outlet grille can be improved, avoiding the air outlet grille being depressed toward the side where the fan blade is located under force and affecting the normal operation of the fan blade.

[0051] In some embodiments, as shown in Figure 1 and Figure 5 the center of the air outlet grille protrudes toward the leeward side, and the value range of the angle α3 between the radial direction of the air outlet grille and the vertical direction is 1° to 5°. By setting the air outlet grille as a convex shape and limiting α3 within the above range, it can not only improve the strength of the air outlet grille, avoid the air outlet grille being depressed toward the side where the fan blade is located under force and affecting the normal operation of the fan blade, but also avoid occupying too much area.

[0052] For example, the included angle α3 between the radial direction and the vertical direction of the air outlet grille takes values such as 1°, 2°, 3°, 4°, or 5°.

[0053] In some embodiments, in combination with Figure 1 As shown, the grille body 100 includes a central disc 102, an outer frame 103, and a plurality of annular ribs 104 with different inner diameters arranged between the outer frame 103 and the central disc 102. The plurality of annular ribs 104 are concentrically arranged with the outer frame 103. Among them, a fixed area 101 is defined between the central disc 102 and the annular ribs 104, between adjacent annular ribs 104, and between the annular ribs 104 and the outer frame 103. The central disc 102, the outer frame 103, and the arrangement between the outer frame 103 and the central disc 102 form the grille body 100, which plays a role in supporting and fixing the guide ribs. Since the guide ribs 200 are arranged in a divergent manner, the distance between adjacent two guide ribs 200 increases gradually from the center of the air outlet grille to the edge of the air outlet grille. By arranging a plurality of annular ribs 200 to enclose a plurality of fixed areas 101, it is convenient to evenly cover the grille body 100 with the guide ribs 200, and at the same time, control the maximum distance between adjacent two guide ribs 200 within a certain range to prevent users from inserting their hands into the grille body.

[0054] In some embodiments, in combination with Figure 1 , Figure 6 and Figure 7 As shown, the outer frame 103 is set to be circular or square. It can be flexibly set according to requirements.

[0055] In some embodiments, in combination with Figure 1 , Figure 6 and Figure 7 As shown, the annular ribs are set to be circular, square, or semi-surrounding. It can be flexibly set according to requirements.

[0056] In some embodiments, in combination with Figure 1 and Figure 8 As shown, the air outlet grille is set to be a flat surface or an arc surface. In this way, it can be adapted to various shapes of household electrical appliances, improving the universality of the air outlet grille. Here, the flat surface is relative to the arc surface, and the slight protrusion of the center of the above-mentioned air outlet grille towards the leeward side is also called a flat surface.

[0057] In some embodiments, fixing holes and buckles are provided on the outer frame. In this way, it is convenient to fix the air outlet grille to the air outlet side of the axial flow fan.

[0058] Specifically, in combination with Figure 1 and Figure 9As shown, there are two recessed parts symmetrically arranged on the left and right of the outer frame 103. Each recessed part is formed with a groove, and a through hole is provided in the groove for a screw to pass through. The recessed part is integrally formed with the outer frame 103 and a support rib is formed at the bottom. The recessed part is flush with the windward side of the outer frame 103. A plurality of buckles are protrudingly arranged outward on the windward side of the outer frame 103, and the buckles are used for rotational snap connection with the outdoor unit housing. Among them, there are 6 buckles, and the 6 buckles are evenly distributed along the circumference of the outer frame 103. A plurality of convex structures integrally formed with the outer frame 103 are also arranged along the circumference of the windward side of the outer frame 103. After rotational snap connection is achieved through the convex structures, support and clamping between the outer frame 103 and the front panel are realized. The height of the convex structure is less than 2 mm.

[0059] When applied to an air conditioner outdoor unit, the air outlet grille is installed on the front panel of the air conditioner outdoor unit housing. An air outlet is provided on the front panel. The air outlet grille is arranged on an arc-shaped card hole provided at the air outlet through a buckle, and is fastened to a stud symmetrically arranged at the air outlet of the front panel through a screw passing through the through hole of the recessed part. Among them, there are 6 arc-shaped card holes, and the 6 card holes are evenly distributed along the air outlet.

[0060] Experimental tests were carried out on the air outlet grille of this application, as follows:

[0061] Table 1

[0062]

[0063]

[0064] Table 1 is Figure 1 shown that the air outlet grille is applied to an air conditioner outdoor unit. Combining Figure 1 as shown, the air volume loss is reduced from 3% - 14% to 0.5% - 1%, and the noise is reduced by 0.5 dB - 1 dB.

[0065] Table 2

[0066] Scheme Rotational Speed, rpm <![CDATA[Air volume, m 3 / h]]> Percentage Loss of Air Volume Compared to Without Air Outlet Grille Without Air Outlet Grille 500 404.3 Original Scheme 500 340.8 15.7％ This Scheme 500 396.2 2.0％

[0067] Table 2 is Figure 8 shown that the air outlet grille is applied to a heat pump water heater. Combining Figure 8 as shown, the air volume loss is reduced from 15.7% to 2.0%.

[0068] In a second aspect, this application provides an axial flow fan. The axial flow fan includes an axial flow fan and the above-mentioned air outlet grille, and the air outlet grille is arranged on the air outlet side of the axial flow fan. On the premise of adopting the above-mentioned air outlet grille, the axial flow fan provided by this application can better guide the air flow direction of the fan blades, reduce the resistance of the air outlet grille to the air flow, thereby reducing the air volume loss and noise.

[0069] In a third aspect, the present application provides a household electrical appliance. The axial flow fan includes an axial flow impeller and the above-mentioned air outlet grille, and the air outlet grille is arranged on the air outlet side of the axial flow impeller. On the premise of adopting the above-mentioned air outlet grille, the household electrical appliance provided by the present application can preferably guide the air flow direction of the fan blades, reduce the resistance of the air outlet grille to the air flow, thereby reducing the air volume loss and noise.

[0070] The household electrical appliances provided by the present application include air conditioners, heat pump water heaters, etc.

[0071] It should be noted that the above-mentioned preferred embodiments are only used to illustrate the principle of the present application and are not intended to limit the protection scope of the present application. Without departing from the principle of the present application, those skilled in the art can adjust the above-mentioned setting methods so that the present application can be applied to more specific application scenarios.

[0072] Those skilled in the art can understand that although some of the embodiments herein include certain features included in other embodiments rather than other features, the combination of the features of different embodiments means that it is within the scope of the present application and forms different embodiments. For example, in the claims of the present application, any one of the claimed embodiments can be used in any combination.

[0073] So far, the technical solutions of the present application have been described in conjunction with the preferred embodiments shown in the drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present application is obviously not limited to these specific embodiments. Without departing from the principle of the present application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present application.

Claims

1. An air outlet grille, characterized in that, The air outlet grille includes: A grille body provided with a fixed area extending along the circumferential direction of the grille body; A plurality of flow guiding ribs arranged at intervals along the circumferential direction of the grille body in the fixed area; Wherein, the inclination angle of the flow guiding rib forms a preset angle with the air inlet direction of the air outlet grille, the upper surface of the flow guiding rib is a concave arc surface, the flow guiding rib includes a windward end face and a leeward end face, and along the windward end face to the leeward end face, the thickness of the flow guiding rib gradually increases and gradually narrows at the leeward end face.

2. The air outlet grille according to claim 1, characterized in that, Both the windward end face and the leeward end face of the flow guiding rib are convex arc surfaces, and the radius of the arc corresponding to the windward end face is smaller than the radius of the arc corresponding to the leeward end face.

3. The air outlet grille according to claim 1, characterized in that, The flow guiding rib includes a strip-shaped cross-section perpendicular to the length direction of the flow guiding rib; the strip-shaped cross-section includes a windward leading edge, a maximum thickness position, and a gradually thickening section located between the windward leading edge and the maximum thickness position; wherein, the length of the positive projection of the gradually thickening section in the axial direction of the air outlet grille is L1, the length of the positive projection of the strip-shaped cross-section in the axial direction is L2, and L1 / L2 = (0.5 - 1).

4. The air outlet grille according to claim 3, wherein The maximum thickness of the strip-shaped cross-section is B1, and B1 / L2 = (0.2 - 0.5); and / or, The strip-shaped cross-section includes a first curve on the windward side and an upper curve connected to the first curve; the tangent at the connection of the first curve and the upper curve is a first tangent, and the value range of the angle between the first tangent and the air inlet direction is [-10°, 10°]; and / or, The strip-shaped cross-section includes a second curve near the leeward side, the tangent at the connection of the second curve and the upper curve is a second tangent, and the value range of the angle between the second tangent and the axial direction is 0° - 10°.

5. The air outlet grille according to claim 3, characterized in that, The strip-shaped cross-section includes a lower profile line, and the lower profile line is a straight line or a convex curve.

6. The air outlet grille according to any one of claims 1 to 5, wherein The center of the air outlet grille protrudes towards the leeward side; or, The center of the air outlet grille protrudes towards the leeward side, and the value range of the angle between the radial direction of the air outlet grille and the vertical direction is 1° - 5°.

7. The air outlet grille according to any one of claims 1 to 5, characterized in that The grille body includes a central disc, an outer frame, and a plurality of annular ribs with different inner diameters arranged between the outer frame and the central disc. The plurality of annular ribs are concentric with the outer frame. Among them, the fixed area is defined between the central disc and the annular ribs, between adjacent annular ribs, and between the annular ribs and the outer frame.

8. The air outlet grille according to claim 7, wherein The outer frame is set to be circular or square; and / or, The annular rib is set to be circular, square or semi-enclosed; and / or, The air outlet grille is set to be a plane or an arc surface; and / or, The outer frame is provided with fixing holes and buckles.

9. An axial flow fan, characterized in that, The axial flow fan includes an axial flow fan and the air outlet grille according to any one of claims 1 to 8, and the air outlet grille is arranged on the air outlet side of the axial flow fan.

10. A household electrical appliance, characterized in that, The household electrical appliance includes an axial flow fan and the air outlet grille according to any one of claims 1 to 8, and the air outlet grille is arranged on the air outlet side of the axial flow fan.

Images