Fan nose component and fan

Abstract

The present invention provides a head assembly of a fan and a fan. The head assembly of the fan includes a grille and a wind blade. A plurality of blades are provided on the wind blade. The grille includes a plurality of grille bars radially distributed. The grille includes a rear grille and a front grille. The wind blade is disposed between the rear grille and the front grille. At least each grille bar of the rear grille is bent in the same direction, and the bending direction is opposite to the rotation direction of the blades of the wind blade. By setting the grille bars of the rear grille to be bent in the same direction and the bending direction to be opposite to the rotation direction of the blades of the wind blade, it is possible to reduce the broadband noise during the operation of the wind blade without increasing the distance between the rear grille and the wind blade, thereby reducing the aerodynamic noise and the overall noise of the fan.

Description

Technical Field

[0001] The present invention relates to the technical field of household appliances, and particularly relates to a head assembly of a fan and a fan. Background Art

[0002] The noise generated by a fan during operation is affected by multiple factors. According to its structure and operating characteristics, fan noise is generally divided into aerodynamic noise, mechanical noise, and electromagnetic noise. Among them, with the progress of motor technology, the mechanical noise and electromagnetic noise generated by the motor have been well controlled, and aerodynamic noise has become the main factor affecting the noise of the fan blade operation.

[0003] Aerodynamic noise is generally divided into discrete noise and broadband noise. Among them, discrete noise generally has a great relationship with the rotation of the fan blade. The fan blade is driven by the motor to generate a high-speed rotating air flow. When the air flow periodically impacts the fan, air duct, fan blade, and air duct grille, multi-band rotational discrete noise will be generated. This rotational noise is difficult to weaken due to the influence of the fan blade, but since this rotational noise is formed by a multi-band combination, the sound is stable and the sound quality is normal.

[0004] Broadband noise is generally caused by the shedding of the trailing edge vortex and tip clearance vortex during the operation of the fan blade, and high-speed eddy currents inside the air duct. Due to the interaction between the high-speed eddy current on the blade surface and the inner wall of the air duct and the front and rear grid bars, this broadband noise will be superimposed on the discrete noise in a certain frequency band, increasing the peak noise of the whole machine. When it comes to the overall sound quality of the air duct, discrete noise with a higher loudness will be heard.

[0005] Generally speaking, during high-speed operation, the rotational noise of the air flow accounts for most of the total sound pressure. This sound has normal sound quality and no noise, but in the design process of the whole machine, not only the noise of the fan blade is considered, but the overall sound quality is considered in combination. Therefore, controlling the eddy current noise on the blade surface will effectively improve the noise sound quality and reduce the noise of the whole machine.

[0006] Currently, the circulation fans in the market generally reduce the eddy current noise of the fan blade by increasing the air inlet size, designing an outwardly concave rear net, installing the motor on the rear net, and lengthening the distance between the fan blade and the rear net. However, this will increase the longitudinal size of the whole circulation fan, making the overall structure too bulky. Summary of the Invention

[0007] Therefore, the technical problem to be solved by the present invention is to overcome the defect that the size of the fan capable of reducing broadband noise in the prior art is relatively large, so as to provide a head assembly of a fan and a fan that can reduce broadband noise while reducing the size of the whole machine.

[0008] The present invention provides a head assembly of a fan, including a grille and a wind blade. A plurality of blades are provided on the wind blade. The grille includes a plurality of grille bars radially distributed. The grille includes a rear grille and a front grille. The wind blade is disposed between the rear grille and the front grille. At least each grille bar of the rear grille is bent in the same direction, and the bending direction is opposite to the rotation direction of the blades of the wind blade.

[0009] Optionally, each grille bar of the front grille is bent in the same direction, and the bending direction is opposite to the rotation direction of the blades of the wind blade.

[0010] Optionally, the air inlet side of the blade is the leading edge of the wind blade. The stagger angle between the leading edge of the wind blade and the grille bar is α. As the leading edge of the wind blade extends from the end far from the center of the wind blade towards the center of the wind blade, α gradually increases. The increase amplitude of α between adjacent two grille bars and the leading edge of the wind blade is γ, and γ satisfies 3° ≤ γ ≤ 8°.

[0011] Optionally, the stagger angle between the end of the leading edge of the wind blade far from the center of the wind blade and the grille bar is α1, and α1 satisfies 80° ≤ α1 ≤ 100°.

[0012] Optionally, α1 = 90°.

[0013] Optionally, the air outlet side of the wind blade is the trailing edge of the wind blade. The stagger angle between the trailing edge of the wind blade and the grille bar is β. As the trailing edge of the wind blade extends from the end far from the center of the wind blade towards the center of the wind blade, β gradually decreases. The decrease amplitude of β between adjacent two grille bars and the trailing edge of the wind blade is δ, and δ satisfies 3° ≤ δ ≤ 8°.

[0014] Optionally, the stagger angle between the end of the leading edge of the wind blade far from the center of the wind blade and the grille bar is β1, and β1 satisfies 80° ≤ β1 ≤ 100°.

[0015] Optionally, β1 = 90°.

[0016] Optionally, the thickness of the grille bar in the bending direction is d0, and d0 satisfies 1 mm ≤ d0 ≤ 4 mm.

[0017] Optionally, d0 = 2.2 mm.

[0018] Optionally, the distance between the ends of adjacent two grille bars far from the center of the wind blade is L1, and L1 satisfies 6 mm ≤ L1 ≤ 8.5 mm.

[0019] Optionally, L1 = 7.7 mm.

[0020] Optionally, the distance between the ends of adjacent two grille bars close to the center of the wind blade is L2, and L2 satisfies 2 mm ≤ L2 ≤ 7 mm.

[0021] Optionally, L2 = 5 mm.

[0022] Optionally, the head assembly of the fan provided by the present invention further includes an air duct structure, the air duct structure has an air inlet end, an air outlet end, and an air duct connecting the air inlet end and the air outlet end, the rear net is connected to the air inlet end, and the front net is connected to the air outlet end.

[0023] Optionally, the head assembly of the fan provided by the present invention further includes a motor for driving the impeller to rotate, and the motor is arranged in the air duct.

[0024] Optionally, the head assembly of the fan provided by the present invention further includes:

[0025] A motor bracket, which is arranged in the air duct and mounts the motor;

[0026] A plurality of guide vane ribs, which are radially arranged in the air duct and connect the motor bracket and the cavity wall of the air duct.

[0027] Optionally, each of the guide vane ribs is bent in the same direction, and the bending direction is opposite to the rotation direction of the blades of the impeller.

[0028] Optionally, the projection of the guide vane rib on the grille bar coincides with the grille bar.

[0029] Optionally, there are three or four guide vane ribs, and they are evenly distributed along the circumferential direction of the air duct structure.

[0030] Optionally, an annular air guiding surface is provided on the rear net, and a drainage surface is provided on the cavity wall of the air duct near the rear net end, and the air guiding surface and the drainage surface are in smooth transition.

[0031] Optionally, the maximum inner diameter of the air guiding surface is D2, and the minimum inner diameter of the drainage surface is D1, then D2 and D1 satisfy 1.05*D1 ≤ D2 ≤ 1.5*D1.

[0032] Optionally, D2 = 1.2*D1.

[0033] The present invention also provides a fan, including the head assembly of the above-mentioned fan.

[0034] Optionally, the fan is a circulation fan.

[0035] The technical solution of the present invention has the following effects:

[0036] 1. The head assembly of the fan provided by the present invention includes two grille nets and a blade disposed between the two grille nets. A plurality of vanes are provided on the blade, and each grille net includes a plurality of grille bars radially distributed; the two grille nets are respectively a rear net and a front net. At least each grille bar of the rear net is bent in the same direction, and the bending direction is opposite to the rotation direction of the vanes of the blade. By setting the grille bars of the rear net to be bent in the same direction and the bending direction to be opposite to the rotation direction of the vanes of the blade, it is possible to reduce the broadband noise during the operation of the blade without increasing the distance between the rear net and the blade, thereby reducing the aerodynamic noise and the overall noise of the fan.

[0037] 2. In the head assembly of the fan provided by the present invention, each grille bar of the front net is bent in the same direction, and the bending direction is opposite to the rotation direction of the vanes of the blade. This can further reduce the broadband noise during the operation of the blade, and thereby further reduce the overall noise of the fan.

[0038] 3. In the head assembly of the fan provided by the present invention, the air inlet side of the vane is the leading edge of the blade, and the stagger angle between the leading edge of the blade and the grille bar is α; as the leading edge of the blade extends from the end far from the center of the blade towards the center of the blade, α gradually increases, and the increase amplitude of the stagger angle α between two adjacent grille bars and the leading edge of the blade is γ, then γ satisfies 3° ≤ γ ≤ 8°. This can further reduce the broadband noise during the operation of the blade, and thereby further reduce the overall noise of the fan; at the same time, it has the effects of increasing the air volume and improving the energy efficiency.

[0039] 4. In the head assembly of the fan provided by the present invention, the stagger angle α1 between the end of the leading edge of the blade far from the center of the blade and the grille bar satisfies 80° ≤ α1 ≤ 100°. This can have a better noise reduction effect.

[0040] 5. In the head assembly of the fan provided by the present invention, the air outlet side of the vane is the trailing edge of the blade, and the stagger angle between the trailing edge of the blade and the grille bar is β; as the trailing edge of the blade extends from the end far from the center of the blade towards the center of the blade, β gradually decreases, and the decrease amplitude of the stagger angle β between two adjacent grille bars and the trailing edge of the blade is δ, then δ satisfies 3° ≤ δ ≤ 8°. This can further reduce the broadband noise during the operation of the blade, and thereby further reduce the overall noise of the fan; at the same time, it has the effects of increasing the air volume and improving the energy efficiency.

[0041] 6. In the head assembly of the fan provided by the present invention, the stagger angle β1 between the end of the leading edge of the blade far from the center of the blade and the grille bar satisfies 80° ≤ β1 ≤ 100°. This can have a better noise reduction effect.

[0042] 7. The head assembly of the fan provided by the present invention further includes a motor for driving the impeller to rotate, and the motor is arranged in the air duct. By arranging the motor in the air duct, compared with arranging the motor outside the air duct, the distance between the rear grille and the impeller can be shortened, and the overall size of the fan can be reduced.

[0043] 8. In the head assembly of the fan provided by the present invention, each of the guide vane ribs is bent in the same direction, and the bending direction is opposite to the rotation direction of the blades of the impeller. This can reduce the power consumption of the motor, thereby making the fan more energy-efficient.

[0044] 9. In the head assembly of the fan provided by the present invention, the projection of the guide vane rib on the grille bar coincides with the grille bar. This can further reduce the power consumption of the motor, thereby making the fan more energy-efficient.

[0045] 10. In the head assembly of the fan provided by the present invention, there are three or four guide vane ribs, which are evenly distributed along the circumferential direction of the air duct structure. This can not only meet the support for the motor mounted on the motor bracket, but also avoid blocking the air due to too many guide vane ribs and affecting the air outlet effect.

[0046] 11. In the head assembly of the fan provided by the present invention, an annular air guiding surface is provided on the rear grille, and a drainage surface is provided on the cavity wall at one end of the air duct close to the rear grille. The air guiding surface and the drainage surface are in smooth transition; the maximum inner diameter of the air guiding surface is D2, and the minimum inner diameter of the drainage surface is D1, and D2 and D1 satisfy 1.05*D1 ≤ D2 ≤ 1.5*D1. This can reduce the inlet air pressure, thereby increasing the air intake of the fan, and at the same time, the eddy current broadband noise can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0048] Figure 1 It is a longitudinal sectional schematic diagram of the fan provided in the first embodiment of the present invention;

[0049] Figure 2 is Figure 1 a three-dimensional exploded schematic diagram of the head assembly of the fan shown;

[0050] Figure 3 is Figure 1 a left view schematic diagram of the fan shown;

[0051] Figure 4 The Figure 1 right view schematic diagram of the fan shown;

[0052] Figure 5 The Figure 4 schematic diagram of the nose assembly of the fan shown;

[0053] Figure 6 The Figure 3 schematic diagram of the nose assembly of the fan shown;

[0054] Figure 7 The Figure 2 cross-sectional schematic diagram of the nose assembly of the fan shown in the assembled state;

[0055] Figure 8 The Figure 2 three-dimensional schematic diagram of the air duct structure in the nose assembly of the fan shown with the motor installed;

[0056] Figure 9 The Figure 8 three-dimensional cross-sectional schematic diagram of the air duct structure shown with the rear net installed;

[0057] Explanation of reference numerals:

[0058] 1 - blade, 11 - leading edge of blade, 12 - trailing edge of blade, 2 - grille bar, 31 - rear net, 32 - front net, 4 - air duct structure, 41 - air duct, 5 - motor, 6 - motor bracket, 7 - guide vane rib, 8 - air guiding surface, 9 - air guiding surface. Specific embodiments

[0059] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0060] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0061] As Figure 1 - Figure 9 shown, this embodiment provides a nose assembly of a fan, including two grille meshes and a blade 1 disposed between the two grille meshes. The blade 1 is provided with a plurality of blades. The grille mesh includes a plurality of grille bars 2 distributed radially; the two grille meshes are respectively a rear net 31 and a front net 32. At least each grille bar 2 of the rear net 31 bends in the same direction, and the bending direction is opposite to the rotation direction of the blades of the blade 1.

[0062] By bending the grid bars 2 of the rear grille 31 into a curved shape that bends in the same direction and with the bending direction opposite to the rotation direction of the blades of the impeller 1, it is possible to reduce the broadband noise during the operation of the impeller 1 without increasing the distance between the rear grille 31 and the impeller 1, thereby reducing the aerodynamic noise and the overall noise of the fan.

[0063] Each grid bar 2 of the front grille 32 bends in the same direction, and the bending direction is opposite to the rotation direction of the blades of the impeller 1. This can further reduce the broadband noise during the operation of the impeller 1, and thereby further reduce the overall noise of the fan. As an alternative embodiment, each grid bar 2 of the front grille 32 can also be in the shape of a straight rod.

[0064] The air inlet side of the blade is the leading edge 11 of the impeller. The stagger angle between the leading edge 11 of the impeller and the grid bar 2 is α; that is, the leading edge 11 of the impeller makes a first tangent line with the intersection point of the leading edge 11 of the impeller and the grid bar 2 as the tangent point, and the grid bar 2 makes a second tangent line with the intersection point of the leading edge 11 of the impeller and the grid bar 2 as the tangent point. The included angle between the first tangent line and the second tangent line is the stagger angle α between the leading edge 11 of the impeller and the grid bar 2 at this intersection point. As the leading edge 11 of the impeller extends from the end far from the center of the impeller 1 towards the center of the impeller 1, α gradually increases, and the increase amplitude of the stagger angle α between two adjacent grid bars 2 and the leading edge 11 of the impeller is γ. Preferably, γ satisfies 3° ≤ γ ≤ 8°. This can further reduce the broadband noise during the operation of the impeller 1, and thereby further reduce the overall noise of the fan; at the same time, it has the effects of increasing the air volume and improving the energy efficiency. For example, γ can be 3°, or γ can be 8°. In this embodiment, γ = 5°.

[0065] The stagger angle between the end of the leading edge 11 of the impeller far from the center of the impeller 1 and the grid bar 2 is α1. Preferably, α1 satisfies 80° ≤ α1 ≤ 100°. This has a better noise reduction effect. For example, α1 can be 80°, or α1 can be 100°. In this embodiment, α1 = 90°.

[0066] The air outlet side of the wind blade 1 is the trailing edge 12 of the wind blade. The staggered angle between the trailing edge 12 of the wind blade and the grille bar 2 is β. That is, a first tangent is made with the intersection point of the trailing edge 12 of the wind blade and the grille bar 2 as the tangent point on the trailing edge 12 of the wind blade, and a second tangent is made with the intersection point of the trailing edge 12 of the wind blade and the grille bar 2 as the tangent point on the grille bar 2. The included angle between the first tangent and the second tangent is the staggered angle β between the trailing edge 12 of the wind blade and the grille bar 2 at this intersection point. When the trailing edge 12 of the wind blade extends from the end far away from the center of the wind blade 1 towards the center of the wind blade 1, β gradually decreases, and the reduction amplitude of the staggered angle β between two adjacent grille bars 2 and the trailing edge 12 of the wind blade is δ. Preferably, δ satisfies 3° ≤ δ ≤ 8°. This can further reduce the broadband noise during the operation of the wind blade 1, and further reduce the overall noise of the fan. At the same time, it has the effects of increasing the air volume and improving the energy efficiency. For example, δ can be 3° or δ can be 8°. In this embodiment, δ = 5°.

[0067] The staggered angle between the end of the leading edge 11 of the wind blade far away from the center of the wind blade 1 and the grille bar 2 is β1. Preferably, β1 satisfies 80° ≤ β1 ≤ 100°. This has a better noise reduction effect. For example, β1 can be 80° or β1 can be 100°. In this embodiment, β1 = 90°.

[0068] It is actually measured that under the same motor 5 and the same wind blade 1 for two groups of grilles with different curvatures, the power of the straight grille fan is 27.5W, and the peak noise is 32.42dB. The power of the curved grille fan in this embodiment is 20.7W, and the peak noise is 26.57dB. The specific test results are as follows in the table:

[0069]

[0070] It can be seen from the above table that for the fan provided in this embodiment, when the grille bars 2 of the rear net 31 and the grille bars 2 of the front net 32 are both bent in the same direction, and the bending direction is opposite to the rotation direction of the wind blade 1, and under the conditions of α1 = 90°, γ = 5°, β1 = 90°, and δ = 5°, its peak noise is significantly less than that of the straight grille fan, the power is also significantly less than that of the straight grille fan, and the energy efficiency is higher than that of the straight grille fan. That is, compared with the straight grille fan, this embodiment can not only achieve noise reduction but also reduce the power of the motor 5 and improve the overall energy efficiency of the machine.

[0071] Actual measurement shows that the relationship between the curvature of the inlet and outlet grilles and the wind blade 1 has a greater impact on the air outlet performance of the whole machine. To ensure the air outlet performance of the whole machine, the thickness of the grille bar 2 in the bending direction is d0. Then preferably, d0 satisfies 1mm ≤ d0 ≤ 4mm. For example, d0 can be 1mm or d0 can be 4mm. In this embodiment, d0 = 2.2mm.

[0072] The distance between the ends of two adjacent grille bars 2 that are far from the center of the fan blade 1 is L1. Preferably, L1 satisfies 6 mm ≤ L1 ≤ 8.5 mm. For example, L1 can be 6 mm or L1 can be 8.5 mm. In this embodiment, L1 = 7.7 mm.

[0073] The distance between the ends of two adjacent grille bars 2 that are close to the center of the fan blade 1 is L2. Preferably, L2 satisfies 2 mm ≤ L2 ≤ 7 mm. For example, L2 can be 2 mm or L2 can be 7 mm. In this embodiment, L1 = 5 mm.

[0074] The head assembly of the fan provided in this embodiment further includes an air duct structure 4. The air duct structure 4 has an air inlet end, an air outlet end, and an air duct 41 connecting the air inlet end and the air outlet end. The rear net 31 is connected to the air inlet end, and the front net 32 is connected to the air outlet end.

[0075] Further, it further includes a motor 5 for driving the fan blade 1 to rotate. The motor 5 is disposed in the air duct 41. By disposing the motor 5 in the air duct 41, compared with disposing the motor 5 outside the air duct 41, the distance between the rear net 31 and the fan blade 1 can be shortened, and the overall size of the fan can be reduced. In other embodiments, the motor 5 can also be disposed outside the air duct 41 and located between the air duct structure 4 and the rear net 31.

[0076] The head assembly of the fan provided in this embodiment further includes a motor bracket 6 and a plurality of guide vane ribs 7.

[0077] The motor bracket 6 is disposed in the air duct 41 and is installed with the motor 5.

[0078] A plurality of guide vane ribs 7 are radially disposed in the air duct 41 and connect the motor bracket 6 and the cavity wall of the air duct 41.

[0079] The guide vane ribs 7 can be straight rod-shaped or curved rod-shaped. In this embodiment, each guide vane rib 7 is bent in the same direction, and the bending direction is opposite to the rotation direction of the blades of the fan blade 1. Further, the projection of the guide vane rib 7 in this embodiment on the grille bar 2 coincides with the grille bar 2. As an alternative embodiment, the projection of the guide vane rib 7 on the grille bar 2 may not coincide with the grille bar 2.

[0080] The simulation results of the air volume and torque of the straight rod-shaped guide vane ribs 7 and the curved rod-shaped guide vane ribs 7 are as follows in the table:

[0081]

[0082]

[0083] As can be seen from the above table, the guide vane rib 7 in this embodiment is in a bent rod shape, and the projection of the guide vane rib 7 on the grille bar 2 coincides with the grille bar 2. Compared with the straight rod-shaped guide vane rib 7, the simulated air volume of the fan remains basically unchanged, but the input power of its motor 5 (torque in the reference table) decreases by 6%, the overall power consumption of the machine decreases, the energy efficiency increases, and the overall efficiency of the machine increases.

[0084] There is no limit to the specific number of the guide vane ribs 7. In this embodiment, the guide vane ribs 7 have four and are evenly distributed along the circumferential direction of the air duct structure 4. This can not only meet the support for the motor 5 installed on the motor bracket 6, but also avoid blocking the air due to too many guide vane ribs 7 and affecting the air outlet effect. As a transformable implementation manner, the guide vane ribs 7 can also have three or five.

[0085] An annular air guiding surface 8 is provided on the rear net 31, and a drainage surface 9 is provided on the cavity wall at one end of the air duct 41 close to the rear net 31. The air guiding surface 8 and the drainage surface 9 are in smooth transition.

[0086] The maximum inner diameter of the air guiding surface 8 is D2, and the minimum inner diameter of the drainage surface 9 is D1. Then it is preferably satisfied between D2 and D1 that 1.05*D1 ≤ D2 ≤ 1.5*D1. This can reduce the inlet air pressure, thereby increasing the air intake volume of the fan, and at the same time can reduce the eddy current broadband noise. For example, it can be D2 = 1.05*D1, or it can be D2 = 1.5*D1. In this embodiment, D2 = 1.2*D1.

[0087] The simulation results of the air volume and torque with and without the air guiding surface 8 are as follows in the table:

[0088] Air volume (m3 / min) Torque The grille has no air guiding surface 19.02 0.064 The grille has an air guiding surface 20.94 0.063

[0089] It can be seen that when there is an air guiding surface on the grille, its air volume increases by 10%, the input power of the motor (torque in the reference table) remains basically unchanged, the inlet air surface pressure is improved, and the maximum eddy current broadband noise decreases.

[0090] This embodiment also provides a fan. Specifically, the fan in this embodiment is a circulation fan.

[0091] Obviously, the above embodiments are only examples given for clear illustration and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of this invention.

Claims

1. A head assembly of a fan, characterized in that, It includes a grille and a wind blade (1). A plurality of blades are provided on the wind blade (1). The grille includes a plurality of grille bars (2) distributed radially. The grille includes a rear grille (31) and a front grille (32). The wind blade (1) is disposed between the rear grille (31) and the front grille (32). At least each grille bar (2) of the rear grille (31) bends in the same direction, and the bending direction is opposite to the rotation direction of the blades of the wind blade (1). The air inlet side of the blade is the leading edge (11) of the wind blade. The stagger angle between the leading edge (11) of the wind blade and the grille bar (2) is α. As the leading edge (11) of the wind blade extends from the end far from the center of the wind blade (1) towards the center of the wind blade (1), α gradually increases, and the increase amplitude of the stagger angle α between two adjacent grille bars (2) and the leading edge (11) of the wind blade is γ. Then γ satisfies 3° ≤ γ ≤ 8°.

2. The head assembly of the fan according to claim 1, wherein Each grille bar (2) of the front grille (32) bends in the same direction, and the bending direction is opposite to the rotation direction of the blades of the wind blade (1).

3. The head assembly of the fan according to claim 1, characterized in that, The stagger angle between the end of the leading edge (11) of the wind blade far from the center of the wind blade (1) and the grille bar (2) is α1. Then α1 satisfies 80° ≤ α1 ≤ 100°.

4. The head assembly of the fan according to claim 1 or 2, characterized in that, The air outlet side of the wind blade (1) is the trailing edge (12) of the wind blade. The stagger angle between the trailing edge (12) of the wind blade and the grille bar (2) is β. As the trailing edge (12) of the wind blade extends from the end far from the center of the wind blade (1) towards the center of the wind blade (1), β gradually decreases, and the decrease amplitude of the stagger angle β between two adjacent grille bars (2) and the trailing edge (12) of the wind blade is δ. Then δ satisfies 3° ≤ δ ≤ 8°.

5. The head assembly of the fan according to claim 4, characterized in that, The stagger angle between the end of the leading edge (11) of the wind blade far from the center of the wind blade (1) and the grille bar (2) is β1. Then β1 satisfies 80° ≤ β1 ≤ 100°.

6. The nose assembly of the fan according to claim 1 or 2, characterized in that, The thickness of the grille bar (2) in the bending direction is d0. Then d0 satisfies 1 mm ≤ d0 ≤ 4 mm.

7. The head assembly of the fan according to claim 1 or 2, characterized in that, The distance between the ends of two adjacent grille bars (2) far from the center of the wind blade (1) is L1. Then L1 satisfies 6 mm ≤ L1 ≤ 8.5 mm.

8. The head assembly of the fan according to claim 1 or 2, characterized in that, The distance between the ends of two adjacent grille bars (2) close to the center of the wind blade (1) is L2. Then L2 satisfies 2 mm ≤ L2 ≤ 7 mm.

9. The head assembly of the fan according to claim 1 or 2, characterized in that, It further includes an air duct structure (4). The air duct structure (4) has an air inlet end, an air outlet end, and an air duct (41) connecting the air inlet end and the air outlet end. The rear grille (31) is connected to the air inlet end, and the front grille (32) is connected to the air outlet end.

10. The head assembly of the fan according to claim 9, characterized in that, It further includes a motor (5) for driving the wind blade (1) to rotate. The motor (5) is disposed in the air duct (41).

11. The head assembly of the fan according to claim 10, characterized in that, It further includes: A motor bracket (6) disposed in the air duct (41) and installed with the motor (5); A plurality of guide vane ribs (7) radially disposed in the air duct (41) and connecting the motor bracket (6) and the cavity wall of the air duct (41).

12. The head assembly of the fan according to claim 11, characterized in that, Each of the guide vane ribs (7) bends in the same direction, and the bending direction is opposite to the rotation direction of the blades of the wind blade (1).

13. The head assembly of the fan according to claim 11, characterized in that, The projection of the guide vane rib (7) on the grille bar (2) coincides with the grille bar (2).

14. The head assembly of the fan according to claim 9, characterized in that, An annular air guiding surface (8) is provided on the rear net (31), and a flow guiding surface (9) is provided on the cavity wall at one end of the air duct (41) close to the rear net (31). The air guiding surface (8) and the flow guiding surface (9) are in smooth transition.

15. The head assembly of the fan according to claim 14, characterized in that, The maximum inner diameter of the air guiding surface (8) is D2, and the minimum inner diameter of the flow guiding surface (9) is D1. Then, 1.05*D1 ≤ D2 ≤ 1.5*D1 is satisfied between D2 and D1.

16. A fan, characterized in that, It includes the nose assembly of the fan according to any one of claims 1-15.

17. The fan according to claim 16, wherein The fan is a circulation fan.

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