An air outlet device

Abstract

The air outlet device provided by the present invention comprises: a hub; a plurality of blades arranged on the hub, wherein the blades are arranged in a double-ended symmetrical airfoil. By arranging the blades in a double-ended symmetrical airfoil, when the blades are driven by an external force and rotate in different directions, the blade shapes of the symmetrically arranged blades in different windward directions are the same, ensuring that the aerodynamic states of the blades are the same when rotating forward and reversely, effectively balancing the air volume on both sides of the hub when rotating forward and reversely, so that both directions can meet the blowing requirements when discharging air in forward and reverse directions.

Description

Technical Field

[0001] The present invention relates to the technical field of fans, and in particular to an air outlet device. Background Art

[0002] Currently, most fans on the market supply air in a single direction, generally using single-layer or double-layer fan blades. They have a wide blowing range and produce soft and comfortable wind. Combined with metal or plastic mesh covers, they can achieve air blowing and cooling, and are deeply loved by consumers.

[0003] Nowadays, the main way to increase the blowing range of the fan is to set up a shaking head device. However, when only two opposite directions need to be affected by wind, with this setting, the blowing range changes slowly and requires additional structure, which increases the cost of the device. In the prior art, the fan's two-way switching of air outlet can be achieved by changing the forward and reverse rotation of the fan blades, thereby meeting the demand for two-way air outlet. However, in the prior art, the aerodynamic states of the fan blades are not the same during the forward and reverse rotation processes, and there are large differences in the air outlets in different directions, which makes it difficult to meet the further needs of users. Summary of the invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defect in the prior art that the air output of the fan blades during forward and reverse rotation varies greatly and is difficult to meet the needs of users, thereby providing an air outlet device.

[0005] The present invention provides an air outlet device, comprising: a hub; and a plurality of fan blades which are arranged on the hub along a circumferential direction, wherein the fan blades are arranged in a double-headed symmetrical airfoil shape.

[0006] Define the line connecting the symmetrical points on the two sides of the wind blade as the mid-chord line, the length of the mid-chord line is L, select one of the symmetrical points as the origin, the extension direction of the mid-chord line is the x-axis, and the extension direction of one side perpendicular to the mid-chord line is the y-axis to establish a coordinate system, the profile line of the wind blade set in the first quadrant is the upper edge line, the coordinates of any point on the upper edge line are (a, b), then when b is at its maximum value, a corresponds to two solution values ​​A1 and A2, 0.1≤A1 / L≤0.4, 0.6≤A2 / L≤0.9.

[0007] When A1≤a≤A2, 0.5mm≤b≤2mm.

[0008] When 0≤a / L≤0.5,

[0009] b=(a / L)*[-151.18(a / L) 3 +212.01(a / L) 2 -106.11(a / L)+19.81]+0.0879.

[0010] The length of the chord line gradually increases from the blade root to the blade top of the wind blade.

[0011] The length of the center chord line corresponding to the blade root position of the fan blade is L1, and the length of the center chord line corresponding to the blade tip position of the fan blade is L2, 40mm≤L1≤50mm, 85mm≤L2≤120mm.

[0012] The included angle between the fan blade and the radial cross section of the hub is β, and β gradually decreases from the root to the top of the fan blade.

[0013] At the blade root position, the angle between the fan blade and the radial cross section of the hub is β1, and at the blade tip position, the angle between the fan blade and the radial cross section of the hub is β2, 40°≤β1≤60°, 25°≤β2≤40°.

[0014] The outer diameter length of the hub is d, the corresponding outer diameter length of the fan blade is D, and 0.2≤d / D≤0.5.

[0015] A plurality of the fan blades are evenly distributed along the outer edge of the hub.

[0016] The number of the fan blades on the hub is N, N is an odd number and N≥3.

[0017] The technical solution of the present invention has the following advantages:

[0018] 1. The air outlet device provided by the present invention comprises: a hub; a plurality of fan blades arranged on the hub, and the fan blades are arranged in a double-headed symmetrical airfoil shape.

[0019] A symmetrical airfoil is one with zero camber, i.e., the arcs on its upper and lower sides are symmetrically arranged, while a double-ended symmetrical airfoil is one with two mutually perpendicular symmetry axes along the cross section of the blade element. The one along the length direction is the mid-chord symmetry axis, and the one along the width direction is the connection line symmetry axis.

[0020] By setting the fan blades to be double-headed symmetrical airfoils, when the fan blades are driven by external force and rotate in different directions, the symmetrically arranged fan blades have the same blade shape in different windward directions, ensuring that the aerodynamic state of the fan blades is the same during forward and reverse rotation, and effectively balancing the air volume on both sides of the hub during forward and reverse rotation, so that the blowing needs can be met in both directions during forward and reverse air discharge.

[0021] 2. The air outlet device provided by the present invention defines the line connecting the symmetrical points on the two sides of the fan blade as the mid-chord line, the length of the mid-chord line is L, one of the symmetrical points is selected as the origin, the extension direction of the mid-chord line is the x-axis, and the extension direction of one side perpendicular to the mid-chord line is the y-axis to establish a coordinate system, the profile line of the fan blade set in the first quadrant is the upper edge line, the coordinates of any point on the upper edge line are (a, b), then when b is at its maximum value, a corresponds to two solution values ​​A1 and A2, 0.1≤A1 / L≤0.4, 0.6≤A2 / L≤0.9.

[0022] Through experiments, it was found that the thickness between the upper and lower profile lines of the fan blade is limited to the maximum value, and its length is located at 0.1 to 0.4 and 0.6 to 0.9 times the length of the mid-chord line. With this setting, not only the air supply volume is similar, but the forward and reverse blowing efficiency can be further optimized, and the aerodynamic performance during the air outlet process is optimized, and the aerodynamic noise during the air outlet process is reduced. While ensuring that the blowing needs can be met in both directions, the user experience is further improved.

[0023] 3. The air outlet device provided by the present invention, when 0≤a / L≤0.5,

[0024] b=(a / L)*[-151.18(a / L) 3 +212.01(a / L) 2 -106.11(a / L)+19.81]+0.0879.

[0025] Experiments have shown that when set in this way, the blade shape is optimized to the greatest extent, effectively balancing the air supply volume, outlet wind speed and aerodynamic noise, effectively reducing wind resistance, and balancing the aerodynamic state of the blade structure on both sides of the symmetry axis of the connecting line, reducing the area of ​​the vortex zone around the blade, thereby reducing turbulent noise and effectively improving the user experience.

[0026] 4. In the air outlet device provided by the present invention, the number of fan blades on the hub is N, N is an odd number and N≥3.

[0027] Using an odd number of fan blades can effectively prevent the fan blades from resonating during rotation, causing problems such as fan blade damage or bearing wear. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 It is a structural schematic diagram of an air outlet device provided in an embodiment of the present invention;

[0030] Figure 2 for Figure 1 A schematic side view of the air outlet device shown;

[0031] Figure 3 for Figure 1 The schematic diagram of the blade structure of the fan blade of the air outlet device shown;

[0032] Figure 4 for Figure 1 A schematic structural diagram of a portion of the upper edge line of a fan blade of an air outlet device shown;

[0033] Figure 5 for Figure 1 A structural schematic diagram corresponding to another representation method of a portion of the upper edge line of the fan blade of the air outlet device shown;

[0034] Figure 6 for Figure 1 The schematic diagram of the structure corresponding to the blade tip position of the fan blade of the air outlet device shown;

[0035] Figure 7 for Figure 1 The schematic diagram of the structure corresponding to the blade root position of the fan blade of the air outlet device shown;

[0036] Figure 8 for Figure 1 The schematic diagram of the change of the length of the chord line at the blade tip position of the wind blade of the wind outlet device corresponding to the wind volume and load power;

[0037] Description of reference numerals:

[0038] 1-hub; 2-blade; 21-center line; 22-connecting line; 23-upper edge line. DETAILED DESCRIPTION

[0039] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0041] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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 a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0042] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0043] like Figure 1 - Figure 5 The present embodiment provides an air outlet device, which is an electric fan in the present embodiment, and may also be other axial flow ventilation appliances or equipment, such as a cooling fan, an exhaust fan, etc., including a hub 1 and a plurality of fan blades 2.

[0044] A plurality of blades 2 are arranged on the hub 1 along the circumferential direction. In this embodiment, the number of blades 2 on the hub 1 is 5, and the blades 2 are evenly distributed along the outer edge of the hub 1 to improve the uniformity of the wind speed. As a convertible implementation, the number of blades 2 on the hub 1 can be other odd numbers greater than or equal to 3. Using an odd number of blades 2 can effectively avoid resonance of the blades 2 during rotation, causing damage to the blades 2 or bearing wear and other problems.

[0045] Furthermore, the fan blade 2 is arranged in a double-ended symmetrical airfoil. Specifically, a symmetrical airfoil refers to an airfoil with zero camber, that is, an airfoil with symmetrically arranged arc lines on its upper and lower sides, and a double-ended symmetrical airfoil refers to an airfoil with two mutually perpendicular symmetry axes along the cross section of the blade element surface of the fan blade 2. The symmetry axis along the length direction is the midchord line 21, and the symmetry axis along the width direction is the connection line 22.

[0046] By setting the fan blade 2 to a double-headed symmetrical airfoil, when the fan blade 2 is driven by an external force and rotates in different rotation directions, the symmetrically arranged fan blade 2 has the same blade shape in different windward directions, ensuring that the aerodynamic state of the fan blade 2 is the same during forward and reverse rotation, and effectively balancing the air volume on both sides of the hub 1 during forward and reverse rotation, so that the blowing needs can be met in both directions during forward and reverse air discharge.

[0047] In addition, if Figure 3 , define the line between the symmetrical points on the two sides of the wind blade 2 as the mid-chord line 21, the length of the mid-chord line 21 is L, select one of the two symmetrical points as the origin, the extension direction of the mid-chord line 21 is the x-axis, and the extension direction of one side perpendicular to the mid-chord line 21 is the y-axis to establish a coordinate system, the y value is half the thickness of the wind blade 2, the profile line of the wind blade 2 set in the first quadrant is the upper edge line 23, the coordinates of any point on the upper edge line 23 are a, b, then when b is at the maximum value, a corresponds to two solution values ​​A1 and A2, 0.1≤A1 / L≤0.4, 0.6≤A2 / L≤0.9. For example, a / L can be 0.1, 0.2, 0.3, 0.6, 0.7, 0.8, 0.9, etc.

[0048] Through experiments, the maximum thickness between the upper and lower profile lines of the fan blade 2 is limited to a length position of 0.1 to 0.4 and 0.6 to 0.9 times the length of the mid-chord line 21. When set in this way, not only the air supply volume is similar, but the forward and reverse blowing efficiency can be further optimized, and the aerodynamic performance during the air outlet process is optimized, and the aerodynamic noise during the air outlet process is reduced. While ensuring that the blowing needs can be met in both directions, the user experience is further improved.

[0049] At the same time, when A1≤a≤A2, 0.5mm≤b≤2mm. Further, when a is 0 or L, the edge of the fan blade is closed, 0≤b≤0.5mm. By limiting the thickness range between the upper and lower profiles of the fan blade 2, on the one hand, the thickness distribution of each position of the fan blade 2 is balanced to avoid the thicker structure at the edge position, excessive centrifugal force, and thinner structure in the middle during the rotation of the fan blade 2, which affects the stability of the overall structure. On the other hand, the load on the power parts is reduced to improve the overall air outlet efficiency. As a convertible embodiment, the range of b is not limited to 0.06mm to 2mm, and the length of b can be adjusted according to its ratio to the length of the center chord line 21 corresponding to the root position of the fan blade, or the ratio to the length of the center chord line 21 corresponding to the top position of the fan blade 2.

[0050] According to the experiment, it can be further obtained that when 0≤a / L≤0.5,

[0051] b=a / L*[-151.18a / L 3 +212.01a / L 2-106.11a / L+19.81]+0.0879. At the same time, when a / L is greater than 0.5, the above formula can be obtained by symmetry of the graph according to the symmetry axis of the connecting line 22.

[0052] Through experiments, it is found that when this setting is used, the blade shape of the fan blade 2 is optimized to the greatest extent, effectively balancing the air volume, outlet wind speed and aerodynamic noise, effectively reducing wind resistance, and balancing the aerodynamic state of the fan blade 2 structure on both sides of the symmetry axis of the connecting line 22, reducing the vortex area around the fan blade 2, thereby reducing turbulent noise and effectively improving the user experience. The specific data is shown in the following table.

[0053]

[0054] Furthermore, the length of the chord line 21 gradually increases from the root to the top of the blade 2. The length of the chord line 21 corresponding to the root position of the blade 2 is L1, and the length of the chord line 21 corresponding to the top position of the blade 2 is L2, 40mm≤L1≤50mm, 85mm≤L2≤120mm. As a convertible embodiment, the lengths of L1 and L2 are not limited to the above ranges, and the lengths of L1 and L2 can be adaptively adjusted according to the corresponding ratio with b.

[0055] The angle between the radial section of the fan blade 2 and the hub 1 is β, and β gradually decreases from the root to the top of the fan blade 2. At the root position, the angle between the radial section of the fan blade 2 and the hub 1 is β1, and at the top position, the angle between the radial section of the fan blade 2 and the hub 1 is β2, 40°≤β1≤60°, 25°≤β2≤40°.

[0056] Experiments have shown that this arrangement can effectively improve the aerodynamic performance of the fan blade 2, balance the aerodynamic state of each position of the fan blade 2 structure, reduce the area of ​​the vortex region around the fan blade 2, effectively reduce turbulent noise, and improve the user experience.

[0057] When the blade has the same angular velocity, the linear velocity increases from the blade root to the blade tip, and the contact area between the blade and the airflow and the utilization rate of the airflow gradually increase. Therefore, the length of the chord line gradually increases from the blade root to the blade tip, which can effectively increase the blade work area, make full use of the airflow, effectively improve the aerodynamic efficiency, increase the air volume of the positive and reverse airflow, and effectively ensure that the load is within the motor matching range. At the same time, when the double-headed symmetrical airfoil blade controls the chord length and installation angle from the blade root to the blade tip within the above preset range, it can improve the aerodynamic efficiency while further reducing the separation of the airflow on the blade surface, reducing the shedding vortex, and improving the noise and sound quality, which can effectively ensure the noise and sound quality experience when the fan blade is rotating forward and reverse.

[0058] Preferably, L1 = 45 mm, β1 = 42°, β2 = 37°, such as Figure 8As shown, when the load power is 25W, L2 is preferably 100mm.

[0059] The outer diameter length of the hub 1 is d, and the corresponding outer diameter length of the blade 2 is D, 0.2≤d / D≤0.5. This setting limits the relative proportion of the hub 1 and the blade 2, ensures the relative diameter length of the blade 2, and combines the length of the chord line 21 of the blade 2 from the root to the top of the blade, so that the overall structure of the blade 2 has sufficient windward area, effectively improving the aerodynamic efficiency of the blade 2. d / D can be 0.2, 0.3, 0.4, 0.5, etc. Preferably, d / D is 0.35. When d / D is 0.3, the upper edge line 23 data of the blade 2 in the range of 0≤a / L≤0.5 is:

[0060] x / L 0 0.0326065 0.066967 0.101401 0.135861 0.170327 0.204792 0.23925 y 0 0.764925 1.03129 1.17824 1.24804 1.2618 1.23493 1.17612 x / L 0.273711 0.308163 0.342613 0.377063 0.411516 0.445973 0.5 y 1.09312 0.993718 0.88614 0.778964 0.680775 0.600164 0.54572

[0061] Obviously, the above embodiments are merely examples for clear explanation, and are not intended to limit the implementation methods. For those skilled 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 methods here. The obvious changes or modifications derived from them are still within the protection scope of the invention.

Claims

1. An air outlet device, characterized in that: include: Wheel hub (1); A plurality of fan blades (2) are arranged on the hub (1) along a circumferential direction, and the fan blades (2) are arranged in a double-ended symmetrical airfoil shape; The line connecting the two symmetrical points on the sides of the fan blade (2) is defined as the mid-chord line (21), the length of the mid-chord line (21) is L, one of the symmetrical points is selected as the origin, the extension direction of the mid-chord line (21) is the x-axis, the extension direction of one side perpendicular to the mid-chord line (21) is the y-axis to establish a coordinate system, the profile line of the fan blade (2) set in the first quadrant is the upper edge line (23), and the coordinates of any point on the upper edge line (23) are (a, b); When 0≤a / L≤0.5, b=(a / L)*[-151.18(a / L)3+212.01(a / L)2-106.11(a / L)+19.81]+0.0879.

2. The air outlet device according to claim 1, characterized in that: When b is at its maximum value, a corresponds to two solution values ​​A1 and A2, 0.1≤A1 / L≤0.4, 0.6≤A2 / L≤0.

9.

3. The air outlet device according to claim 2, characterized in that: When A1≤a≤A2, 0.5mm≤b≤2mm.

4. The air outlet device according to any one of claims 2 to 3, characterized in that: Along the blade root to the blade top of the wind blade (2), the length of the chord line (21) gradually increases.

5. The air outlet device according to claim 4, characterized in that: The length of the blade root position of the fan blade (2) corresponding to the mid-chord line (21) is L1, and the length of the blade tip position of the fan blade (2) corresponding to the mid-chord line (21) is L2, 40mm≤L1≤50mm, 85mm≤L2≤120mm.

6. The air outlet device according to claim 1, characterized in that: The included angle between the fan blade (2) and the radial cross section of the hub (1) is β, and β gradually decreases from the blade root to the blade top of the fan blade (2).

7. The air outlet device according to claim 6, characterized in that: At the blade root position, the angle between the fan blade (2) and the radial cross section of the hub (1) is β1, and at the blade tip position, the angle between the fan blade (2) and the radial cross section of the hub (1) is β2, 40°≤β1≤60°, 25°≤β2≤40°.

8. The air outlet device according to claim 1, characterized in that: The outer diameter length of the hub (1) is d, the corresponding outer diameter length of the fan blade (2) is D, and 0.2≤d / D≤0.

5.

9. The air outlet device according to claim 1, characterized in that: The plurality of fan blades (2) are evenly distributed along the outer edge of the hub (1).

10. The air outlet device according to claim 1, characterized in that: The number of the fan blades (2) on the wheel hub (1) is N, N is an odd number and N≥3.

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