Fan blade, fan and blowing equipment

Abstract

The invention discloses a fan blade, a fan and blowing equipment, the fan blade comprises a hub and a blade, the blade is connected with the hub, and the blade comprises a first segment, a second segment and a bridging segment connected with the outer end of the first segment and the outer end of the second segment; at least part of the first segment and at least part of the second segment are arranged at intervals in the circumferential direction and / or the axial direction of the hub, the hollow area is defined by the first segment, the bridging segment and the second segment, and the first segment, the bridging segment and the second segment are in smooth transition; the outer contour lines of the bridging segments are formed through curve fitting. According to the technical scheme, the noise generated when the fan blades operate can be effectively reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of blowing devices, and particularly to a fan blade, a fan, and a blowing device. Background Art

[0002] Blowing devices are widely used in people's daily lives. Among them, the blowing device with an axial flow fan blade (such as a floor fan) is favored by many users because of its large wind force and wide blowing range. The existing blowing devices with axial flow fan blades mainly adopt the form of multiple solid blades protruding from the hub. When the blowing device is set to a larger gear, the noise is often relatively large, which will cause certain troubles to users. At present, some blowing devices usually make some bionic shape structures at the tails of the blades to reduce noise, but the noise reduction effect is limited. Therefore, it is urgent to adopt other solutions to effectively reduce the noise generated during the operation of the fan blade. Summary of the Invention

[0003] The main object of the present invention is to propose a fan blade, aiming to effectively reduce the noise generated during the operation of the fan blade.

[0004] To achieve the above object, the fan blade proposed by the present invention includes:

[0005] A hub;

[0006] Blades, connecting to the hub. The blades include a first segment, a second segment, and a bridging segment connecting the outer ends of the first segment and the second segment. At least part of the first segment and the second segment are spaced apart in the circumferential direction and / or the axial direction of the hub. A hollow area is enclosed among the first segment, the bridging segment, and the second segment, and a smooth transition is formed among the first segment, the bridging segment, and the second segment. The outer contour line of the bridging segment is formed by curve fitting.

[0007] Optionally, the outer contour of the fan blade has a first radius R1. Taking a cylinder with a radius of r1 as a reference cylinder surface, it satisfies 0.9R1 ≤ r1 ≤ 0.95R1. The reference cylinder surface cuts the first segment to form a first cross-section. The first cross-section has a first chord length L1. The suction side of the first cross-section has a first control point. The distance from the first control point to the leading edge of the first cross-section is 1%L1;

[0008] The reference cylinder surface cuts the second segment to form a second cross-section. The second cross-section has a second chord length L2. The pressure side of the second cross-section has a second control point. The distance from the second control point to the leading edge of the second cross-section is 1%L2;

[0009] The first maximum control point is obtained from the first radius R1. The first control point has a first vector, and the second control point has a second vector. The first contour boundary of the bridging segment is obtained by spline curve fitting.

[0010] The pressure side of the first section has a third control point, and the distance from the third control point to the leading edge of the first section is 1%L1. The suction side of the second section has a fourth control point, and the distance from the fourth control point to the leading edge of the second section is 1%L2.

[0011] The leading edge of the bridging segment has a first preset thickness Tle. The second maximum control point is obtained from the first maximum control point and the first preset thickness Tle. The third control point has a third vector, and the fourth control point has a fourth vector. The second contour boundary of the bridging segment is obtained by spline curve fitting. The first contour boundary and the second contour boundary jointly define the front-end contour of the bridging segment.

[0012] Optionally, the suction side of the first section further has a fifth control point, and the distance from the fifth control point to the trailing edge of the first section is 1%L1. The pressure side of the second section further has a sixth control point, and the distance from the sixth control point to the trailing edge of the second section is 1%L2.

[0013] The third maximum control point is obtained from the first radius R1. The fifth control point has a fifth vector, and the sixth control point has a sixth vector. The third contour boundary of the bridging segment is obtained by spline curve fitting.

[0014] The pressure side of the first section further has a seventh control point, and the distance from the seventh control point to the trailing edge of the first section is 1%L1. The suction side of the second section has an eighth control point, and the distance from the eighth control point to the trailing edge of the second section is 1%L2.

[0015] The trailing edge of the bridging segment has a second preset thickness Tte. The fourth maximum control point is obtained from the third maximum control point and the second preset thickness Tte. The seventh control point has a seventh vector, and the eighth control point has an eighth vector. The fourth contour boundary of the bridging segment is obtained by spline curve fitting. The fourth contour boundary and the third contour boundary jointly define the rear-end contour of the bridging segment, and the first contour boundary, the second contour boundary, the third contour boundary, and the fourth contour boundary jointly define the bridging segment.

[0016] Optionally, the outer contour of the fan blade has a first radius R1. Using a cylinder with a radius of r1 as the reference cylindrical surface, satisfying 0.9R1 ≤ r1 ≤ 0.95R1, the reference cylindrical surface cuts the first segment to form a first cross-section, and the reference cylindrical surface cuts the second segment to form a second cross-section. When the reference cylindrical surface is unfolded flat, the included angle βth formed by the first extension line of the pressure side of the first cross-section and the second extension line of the suction side of the second cross-section satisfies 10° ≤ βth ≤ 30°.

[0017] Optionally, the first cross-section has a first chord length L1. The suction side of the first cross-section has a fifth control point, and the pressure side of the first cross-section also has a seventh control point. The distances from the fifth control point and the seventh control point to the trailing edge of the first cross-section are both 1%L1. The distance between the fifth control point and the seventh control point is T1te, and the distance from the seventh control point to the second extension line is Wth.

[0018] The second cross-section has a second chord length L2. The pressure side of the second cross-section has a second control point, and the suction side of the second cross-section has a fourth control point. The distances from the second control point and the fourth control point to the leading edge of the second cross-section are both 1%L2. The distance between the second control point and the fourth control point is T2le.

[0019] If 0 ≤ Wth ≤ min(T1te, T2le), the chord length of the outer end of the first segment is greater than the chord length of the outer end of the second segment.

[0020] If Wth ≥ T1te + T2le, the chord length of the outer end of the first segment is equal to the chord length of the outer end of the second segment.

[0021] Optionally, the outer contour of the fan blade has a first radius R1. Using a cylinder with a radius of r1 as the reference cylindrical surface, satisfying 0.9R1 ≤ r1 ≤ 0.95R1, the reference cylindrical surface cuts the first segment to form a first cross-section, and the reference cylindrical surface cuts the second segment to form a second cross-section.

[0022] Both the first cross-section and the second cross-section protrude away from the air inlet direction of the fan blade; or,

[0023] The first cross-section protrudes away from the air inlet direction of the fan blade, and the second cross-section protrudes along the air inlet direction of the fan blade.

[0024] Optionally, the inner ends of the first segment and the second segment are respectively connected to the hub, and the outer side surfaces of the first segment, the second segment, and the hub jointly define the hollow area.

[0025] Alternatively, the inner end of the first segment is connected to the side edge of the second segment, and the inner end of the second segment is connected to the hub;

[0026] Alternatively, the inner ends of the first segment and the second segment are connected to each other and are simultaneously connected to the hub.

[0027] Optionally, the hub is provided with N vanes, and 2 ≤ N ≤ 9.

[0028] The present invention also provides a fan, including the impeller as described above, and a driving member connected to the impeller, the driving member being configured to drive the impeller to rotate.

[0029] The present invention also provides a blowing device, characterized by including the impeller as described above or the fan as described above.

[0030] In the technical solution of the present invention, by providing vanes on the hub, the vanes include a first segment, a second segment, and a bridging segment connecting the outer ends of the first segment and the second segment. At least part of the first segment and the second segment are spaced apart in the circumferential direction and / or the axial direction of the hub. The hollow region is jointly defined by the first segment, the bridging segment, the second segment, and the hub. In the rotation direction of the impeller, the first segment is located upstream of the second segment. When the impeller rotates, most of the airflow can be directly blown out forward from the pressure surfaces of the first segment and the second segment. At the same time, the airflow vortex at the trailing edge of the pressure surface of the first segment can flow to the pressure surface of the second segment. In this way, the airflow vortex at the trailing edge of the first segment can be absorbed by the second segment, reducing the possibility of a large amount of noise generated by the direct shedding of the airflow vortex at the tail of the first segment, thereby effectively reducing the noise of the impeller. The first segment, the second segment, and the bridging segment jointly define a hollow region, and the three are smoothly transitioned, making the fan shape smooth, which can reduce the resistance of the airflow flowing along the hollow region, thereby further reducing the noise. And the outer contour line of the bridging segment is formed by curve fitting. The boundary contour of the bridging segment is obtained through multiple curve fittings, and then the shape of the bridging segment is obtained, thereby realizing precise geometric control of the curved surface of the bridging segment, realizing control of the flow area and angle of the airflow passing through the hollow region, and further controlling the airflow velocity in the hollow region. It can also further reduce the tip vortex at the blade tip of the vane, thereby reducing the noise of the impeller. On the other hand, it can also improve the work capacity of the impeller. Description of the Drawings

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0032] Figure 1 Schematic diagram of the structure of the first embodiment of the fan blade of the present invention;

[0033] Figure 2 Schematic diagram of the structure of the second embodiment of the fan blade of the present invention;

[0034] Figure 3 is Figure 2 Schematic diagram of the structure of the blade cut by the reference cylindrical surface in;

[0035] Figure 4 is Figure 3 Partial enlarged view at the first section and the second section in;

[0036] Figure 5 is Figure 2 Plane development view of the first section and the second section in;

[0037] Figure 6 Plane development view of the first section and the second section in the third embodiment of the fan blade of the present invention;

[0038] Figure 7 Schematic diagram of the structure of the fourth embodiment of the fan blade of the present invention;

[0039] Figure 8 is Figure 7 Schematic diagram of the structure of the blade cut by the reference cylindrical surface in;

[0040] Figure 9 is Figure 8 Plane development view of the first section and the second section in;

[0041] Figure 10 Schematic diagram of the structure of the fifth embodiment of the fan blade of the present invention;

[0042] Figure 11 Schematic diagram of the structure of the sixth embodiment of the fan blade of the present invention.

[0043] Explanation of the reference numerals in the drawings:

[0044] Reference numeral Name Reference numeral Name 100 Fan blade 125 First cross-section 110 Hub 125a First suction side 120 Vane 125b First pressure side 121 Hollow region 125c First leading edge 122 First segment 125d First trailing edge 123 Second segment 126 Second cross-section 124 Bridging segment 126a Second suction side 124a First profile boundary 126b Second pressure side 124b Second profile boundary 126c Second leading edge 124c Third profile boundary 126d Second trailing edge 124d Fourth profile boundary 200 Reference cylindrical surface

[0045] The realization, functional features and advantages of the object of the present invention will be further described with reference to the embodiments and the accompanying drawings. Detailed implementation manners

[0046] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0047] It should be noted that if the embodiments of the present invention involve directional indications such as up, down, left, right, front, back..., then such directional indications are only used to explain the relative positional relationship, movement conditions, etc. between components in a specific posture as shown in the drawings. If this specific posture changes, the directional indications will also change accordingly.

[0048] In addition, if the embodiments of the present invention involve descriptions such as "first", "second", etc., then such descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, the meaning of "and / or" appearing throughout the text is that it includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, or solution B, or a solution where both A and B are satisfied simultaneously. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0049] The present invention provides a fan blade 100.

[0050] In the embodiments of the present invention, as Figures 1 to 11 shown, the fan blade 100 includes a hub 110 and blades 120. The blades 120 are connected to the hub 110. The blades 120 include a first segment 122, a second segment 123, and a bridging segment 124 connecting the outer ends of the first segment 122 and the second segment 123. At least part of the first segment 122 and the second segment 123 are spaced apart in the circumferential and / or axial directions of the hub 110, and a hollow region 121 is defined among the first segment 122, the bridging segment 124, and the second segment 123. Moreover, a smooth transition is formed among the first segment 122, the bridging segment 124, and the second segment 123, and the outer contour line of the bridging segment 124 is formed by curve fitting.

[0051] Specifically, referring to Figure 1 、 Figure 2 、 Figure 7 、 Figure 10 and Figure 11, the fan blade 100 includes a hub 110 and N blades 120 disposed on the outer periphery of the hub 110. The number of the blades 120 can be set according to actual needs, generally set to at least two. For example, it can be two, three, five or more; preferably, 2 ≤ N ≤ 9. For the convenience of description, the structure of a single blade 120 will be mainly described below, and the structures of the other blades 120 are the same as or similar to that of this blade 120. The inner end (root) of the blade 120 is connected to the hub 110, and there are various connection methods. For example, the blade 120 and the hub 110 can be integrally formed, or they can also be assembled together through assembly structures such as screws and buckles, which will not be specifically limited herein.

[0052] It can be understood that for the current traditional axial-flow fan blade 100, part of its noise comes from the shedding vortices formed at the tail of the blade 120 when the fan blade 100 rotates. That is, when the fan blade 100 rotates, an air flow vortex will be formed at the tail of the blade 120. The direct shedding of the air flow vortex from the trailing edge of the blade 120 will generate relatively large noise, resulting in relatively large noise during the operation of the entire fan blade 100, bringing trouble to users and affecting the user experience. In this solution, a hollow area 121 is formed on the blade 120. The hollow area 121 has a certain guiding effect on the air flow on the blade 120. When the fan blade 100 rotates, the air flow at the trailing edge of the first segment 122 is guided along the suction surface of the first segment 122 to the pressure surface of the second segment through the hollow area 121. In this way, the air flow vortices at the trailing edge of the fan blade 100 can be dispersed, avoiding the direct outward detachment of the air flow vortices from the trailing edge of the blade 120 to generate relatively large shedding vortex noise, so that a good noise reduction effect can be achieved, effectively reducing the noise generated during the operation of the fan blade 100 and improving the user experience.

[0053] In this embodiment, referring to Figure 1 , Figure 2 and Figure 7, the blade 120 includes a first segment 122, a second segment 123, and a bridging segment 124 connecting the outer ends of the first segment 122 and the second segment 123. At least part of the first segment 122 and the second segment 123 are spaced apart circumferentially and / or axially of the hub 110, and there is a smooth transition among the first segment 122, the bridging segment 124, and the second segment 123, and they jointly define a hollow region 121. Specifically, the first segment 122, the bridging segment 124, and the second segment 123 jointly enclose to form an annular structure, and the hollow region 121 is the center of the annular structure. And at least part of the first segment 122 and the second segment 123 are spaced apart circumferentially and / or axially of the hub 110, that is, at least part of the first segment 122 and the second segment 123 can be spaced only in the axial direction of the hub 110. At this time, the first segment 122 and the second segment 122 are axially opposite to each other on the hub 110, and the corresponding hollow region 121 has a certain thickness. It can also be spaced only in the circumferential direction of the hub 110. At this time, the first segment 122 and the second segment 122 are circumferentially opposite to each other on the hub 110, and the corresponding hollow region 121 has a certain width. Or at least part of the first segment 122 and the second segment 123 are spaced both in the axial and circumferential directions of the hub 110. At this time, the first segment 122 and the second segment 123 are misaligned on the hub 110.

[0054] And there are various specific construction methods for the hollow region 121. In one embodiment, the inner ends of the first segment 122 and the second segment 123 are respectively connected to the hub 110. That is, at this time, the blade 120 is divided into two spaced-apart sub-blades on the hub 110, so that the first segment 122, the second segment 123, and the hub 110 jointly enclose to form an annular structure. In this way, the effective lengths of the first segment 122 and the second segment 123 can be increased, thereby enhancing the total work capacity of the blade 120. It should be noted that the inner end of the blade 120 refers to the end close to the hub 110, and the outer end refers to the end far from the hub 110. That is, the inner end of the blade 120 corresponds to its root part, and the outer end of the blade 120 corresponds to its tip part.

[0055] In another embodiment, the hollow region 122 can also be directly opened on the blade 120 body and is arranged close to the outer end of the blade 120. For example, in another embodiment, refer to Figure 11, the inner end of the first segment 122 is connected to the side edge of the second segment 123, and the inner end of the second segment 123 is connected to the hub 110; that is, the inner end of the second segment 123 serves as the root of the blade 120 and is directly connected to the hub 110, while the first segment 122 is not directly connected to the hub 110, that is, the end of the blade 120 away from the hub 110 is bent and circuitous in the direction opposite to the rotation direction of the fan blade 100 to form the hollow area 122. In this way, the root of the blade 120 can be made smaller, which is conducive to reducing the weight of the blade 120.

[0056] In yet another embodiment, referring to Figure 10 , the inner end of the first segment 122 and the inner end of the second segment 123 are connected and connected to the hub 110. That is, the root of the blade 120 is composed of the first segment 122 and the second segment 123, and the hollow area 121 is directly opened on the blade 120. In this way, the structural strength of the root of the blade 120 can be improved.

[0057] The hollow area 121 is defined by the first segment 122, the bridge segment 124, the second segment 123 and the hub 110. Figure 1 , Figure 2 and Figure 7, the inner ends of the first segment 122 and the second segment 123 are respectively connected to the hub 110, and the first segment 122, the bridging segment 124, the second segment 123 and the hub 110 together define a hollow region 121. Specifically, in the rotational direction of the fan blade 100, the first segment 122 is located upstream of the second segment 123. When the fan blade 100 rotates, most of the airflow can be directly blown out forward from the pressure surfaces of the first segment 122 and the second segment 123. At the same time, the airflow vortex at the trailing edge of the suction surface of the first segment 122 can flow to the pressure surface of the second segment 123. In this way, the airflow vortex at the trailing edge of the first segment 122 can be absorbed by the second segment 123, reducing the direct shedding of the airflow vortex at the tail of the first segment 122 and generating relatively large noise, so that the noise of the fan blade 100 can be effectively reduced. The bridging segment 124 connects the outer end of the first segment 122 and the outer end of the second segment 123, and there is a smooth transition among the first segment 122, the bridging segment 124 and the second segment 123, jointly defining the hollow region 121 with the hub 110. The first segment 122, the second segment 123 and the bridging segment 124 enclose the hollow region 121, and there is a smooth transition among the three, making the fan shape smooth, which can reduce the resistance of the airflow flowing along the hollow region 121, and thus can further reduce the noise. Moreover, the outer contour line of the bridging segment 124 is formed by curve fitting. The boundary contour of the bridging segment 124 is obtained through multiple curve fittings, and then the shape of the bridging segment 124 is obtained, so as to achieve precise geometric control of the curved surface of the bridging segment 124, realize the control of the flow area and angle in the hollow region 121, and then control the airflow velocity in the hollow region 121. It can also further reduce the tip vortex at the tip of the blade 110, thereby reducing the noise of the fan blade 100. On the other hand, it can also improve the work capacity of the fan blade 100.

[0058] Among them, in one embodiment, the first segment 122, the second segment 123 and the bridging segment 124 are integrally formed, making the overall structural strength of the blade 120 higher and the stability better. At the same time, it can also simplify the manufacturing process. The hollow region 121 can also reduce the weight of the blade 120, and further reduce the overall weight of the fan blade 100. In this way, only a smaller driving force is required to drive the fan blade 100 to rotate. Alternatively, in other embodiments, a filter screen can also be provided in the hollow region 121, which can also play a role in filtering and purifying.

[0059] The technical solution of the present invention is to provide blades 120 on the hub 110. The blade 120 includes a first segment 122, a second segment 123, and a bridging segment 124 connecting the outer ends of the first segment 122 and the second segment 123. At least part of the first segment 122 and the second segment 123 are spaced apart in the circumferential and / or axial directions of the hub 110. The hollow region 121 is jointly defined by the first segment 122, the bridging segment 124, the second segment 123, and the hub 110. In the rotation direction of the fan blade 100, the first segment 122 is located upstream of the second segment 123. When the fan blade 100 rotates, most of the air flow can be directly blown out forward from the pressure surfaces of the first segment 122 and the second segment 123. At the same time, the air flow vortex at the trailing edge of the suction surface of the first segment 122 can flow to the pressure surface of the second segment 123. In this way, the air flow vortex at the trailing edge of the first segment 122 can be absorbed by the second segment 123, reducing the possibility of a large amount of noise generated by the direct shedding of the air flow vortex at the tail of the first segment 122, thereby effectively reducing the noise of the fan blade 100. The first segment 122, the second segment 123, and the bridging segment 124 jointly define the hollow region 121, and the three are smoothly transitioned, making the fan shape smooth, which can reduce the resistance of the air flow flowing along the hollow region 121, thereby further reducing the noise. Moreover, the outer contour line of the bridging segment 124 is formed by curve fitting. The boundary contour of the bridging segment 124 is obtained through multiple curve fittings, and then the shape of the bridging segment 124 is obtained, so as to achieve precise geometric control of the curved surface of the bridging segment 124, realize the control of the flow area and angle of the air flow passing through the hollow region 121, and then control the air flow velocity in the hollow region 121. It can also further reduce the tip vortex at the tip of the blade 110, thereby reducing the noise of the fan blade 100. On the other hand, it can also improve the work capacity of the fan blade 100.

[0060] Referring to Figures 1 to 9 , in an embodiment, the outer contour of the fan blade 100 has a first radius R1. A reference cylindrical surface 200 is made with a cylinder having a radius of r1, satisfying 0.9R1 ≤ r1 ≤ 0.95R1. The reference cylindrical surface 200 cuts the first segment 122 to form a first cross-section 125. The first cross-section 125 has a first chord length L1. The suction side of the first cross-section 125 has a first control point, and the distance from the first control point to the leading edge of the first cross-section 125 is 1% L1;

[0061] The reference cylindrical surface 200 cuts the second segment 123 to form a second cross-section 126. The second cross-section 126 has a second chord length L2. The pressure side of the second cross-section 126 has a second control point, and the distance from the second control point to the leading edge of the second cross-section 126 is 1% L2;

[0062] The first maximum control point is obtained from the first radius R1. The first control point has a first vector, and the second control point has a second vector. Through spline curve fitting, the first contour boundary 124a of the bridging segment 124 is obtained.

[0063] The pressure side of the first cross-section 125 has a third control point. The distance from the third control point to the leading edge of the first cross-section 125 is 1% L1. The suction side of the second cross-section 126 has a fourth control point. The distance from the fourth control point to the leading edge of the second cross-section 126 is 1% L2.

[0064] The leading edge of the bridging segment 124 has a first preset thickness Tle. From the first maximum control point and the first preset thickness Tle, the second maximum control point is obtained. The third control point has a third vector, and the fourth control point has a fourth vector. Through spline curve fitting, the second contour boundary 124b of the bridging segment 124 is obtained. The first contour boundary 124a and the second contour boundary 124b jointly define the front-end contour of the bridging segment 124.

[0065] Specifically, for the convenience of description, the suction surface of the blade 120 is the side where the suction side of the first cross-section 125 is located, which is the suction surface of the first segment 122, temporarily set as the first suction side 125a. The pressure side of the first cross-section 125 is the side where the pressure surface of the first segment 122 is located, temporarily set as the first pressure side 125b. The suction side of the second cross-section 126 is the side where the suction surface of the second segment 123 is located, temporarily set as the second suction side 126a. The pressure side of the first cross-section 125 is the side where the pressure surface of the first segment 122 is located, temporarily set as the second pressure side 126b. The leading edge of the first cross-section 125 is the edge where the air flow starts to enter the first segment 122, temporarily set as the first leading edge 125c. The leading edge of the second cross-section 126 is the edge where the air flow starts to enter the second segment 123, temporarily set as the second leading edge 126c. Refer to Figure 6 and Figure 9 , let the first control point be S1, the second control point be P1, the third control point be P2, the fourth control point be S2, the first maximum control point be P, the second maximum control point be P', the first tangential vector be The second tangential vector is The third tangential vector is The fourth tangential vector is Refer to Figure 3 and Figure 8 , the radius r1 of the reference cylindrical surface 200 satisfies 0.9R1 ≤ r1 ≤ 0.95R1, that is, the reference cylindrical surface 200 cuts the outer end (blade tip) of the blade 120, so that the reference cylindrical surface 200 cuts the first segment 122 to obtain the first cross-section 125, and the reference cylindrical surface 200 cuts the second segment 123 to obtain the second cross-section 126. As Figure 4As shown, the first section 125 has a first chord length L1 (the length formed by connecting the first leading edge 125c and the first trailing edge 125d), and the second section 126 has a second chord length L2 (the length formed by connecting the first leading edge 125c and the first trailing edge 125d). Referring to Figure 5 、 Figure 6 and Figure 9 , the first control point S1 is the point on the first suction side 125a that is 1% L1 away from the first leading edge 125c, corresponding to the first tangential vector The second control point P1 is the point on the second pressure side 126b that is 1% L2 away from the second leading edge 126c, corresponding to the second tangential vector This first maximum control point P must fall on the circumferential circle where the outer contour of the fan blade 100 is located, so that the radial position of the first maximum control point P on the fan blade 100 is known. Its axial position should be within the width range of the hub 110, and its circumferential position should be clamped between the first control point S1 and the second control point P1. Therefore, from the known first control point S1, the second control point P1, their corresponding tangent vectors, and the position range of the first maximum control point P, n + 1 d-order B-spline curve control points are obtained,

[0066]

[0067] where, N i,d (u) is the basis function of the d-order B-spline curve.

[0068]

[0069] Thus, a smooth curve is obtained through the above B-spline curve fitting, and this curve is the first contour boundary 124a of the bridging segment 124.

[0070] Referring again to Figures 4 to 9 , the third control point P2 is the point on the first pressure side 125b that is 1% L1 away from the first leading edge 125c, corresponding to the third tangential vector The fourth control point S2 is the point on the second suction side 126a that is 1% L2 away from the second leading edge 126c, corresponding to the fourth tangential vector The second-largest control point P’ must fall on the circumference with a radius of R1 - Tle, such that the radial position of the second-largest control point P’ on the fan blade 100 is known. Its axial position should be within the width range of the hub 110, and its circumferential position should be between the third control point P2 and the fourth control point S2. Therefore, from the known third control point P2, the fourth control point S2, their corresponding tangent vectors, and the position range of the second-largest control point P’, a smooth curve is obtained again through d-order B-spline curve fitting. This curve is the second contour boundary 124b of the bridging segment 124. The first contour boundary 124a and the second contour boundary 124b jointly define the front contour of the bridging segment 124, thereby precisely controlling the front contour of the bridging segment 124, ensuring a smooth connection at the leading edge of the blade 120, and further controlling the air flow velocity entering the hollow region 121, thereby reducing noise.

[0071] Among them, the distance between the first control point S1 and the third control point P2 is T1le, and the distance between the second control point P1 and the fourth control point S2 is T2le. Generally, Tle, T1le, and T2le satisfy T1le ≤ Tle ≤ T2le, that is, the first preset width Tle is within the width range of T1le and T2le. It can be understood that referring to Figure 2 , the pressure side of the blade 120 is the side where the blade 120 moves relative to the air flow, that is, the direction of the air flow faced by the blade. Correspondingly, the suction side of the blade 120 refers to the other side where the blade 120 moves relative to the air flow, that is, the direction of the blade 120 that the air flow turns away from.

[0072] Furthermore, referring again to Figures 4 to 9 , the suction side of the first cross-section 125 also has a fifth control point, and the distance from the fifth control point to the trailing edge of the first cross-section 125 is 1% L1. The pressure side of the second cross-section 126 also has a sixth control point, and the distance from the sixth control point to the trailing edge of the second cross-section 126 is 1% L2;

[0073] The third-largest control point is obtained from the first radius R1. The fifth control point has a fifth vector, and the sixth control point has a sixth vector. A third contour boundary 124c of the bridging segment 124 is obtained through spline curve fitting;

[0074] The pressure side of the first cross-section 125 also has a seventh control point, and the distance from the seventh control point to the trailing edge of the first cross-section 125 is 1% L1; the suction side of the second cross-section 126 has an eighth control point, and the distance from the eighth control point to the trailing edge of the second cross-section 126 is 1% L2;

[0075] The trailing edge of the bridging segment 124 has a second preset thickness Tte. The fourth maximum control point is obtained from the third maximum control point and the second preset thickness Tte. The seventh control point has a seventh vector, and the eighth control point has an eighth vector. Through spline curve fitting, the fourth contour boundary 124d of the bridging segment 124 is obtained. The fourth contour boundary 124d and the third contour boundary 124c jointly define the trailing contour of the bridging segment 124, and the first contour boundary 124a, the second contour boundary 124b, the third contour boundary 124c, and the fourth contour boundary 124d jointly define the bridging segment 124.

[0076] Specifically, for the convenience of explanation, the trailing edge of the first cross-section 125 is the edge where the air flow exits the first segment 122, temporarily set as the first trailing edge 125d. The trailing edge of the second cross-section 126 is the edge where the air flow exits the second segment 123, temporarily set as the second trailing edge 126d. Referring to Figure 6 and Figure 9 , let the fifth control point be S3, the sixth control point be P3, the seventh control point be P4, the eighth control point be S4, the third maximum control point be S, the fourth maximum control point be S', the fifth tangential vector be The sixth tangential vector is The seventh tangential vector is The eighth tangential vector is The fifth control point, S3 is the point on the first suction side 125a where the distance to the first trailing edge 125d is 1% of L1, and the corresponding fifth tangential vector is The sixth control point is P3, which is the point on the second pressure side 126b where the distance to the second trailing edge 126d is 1% of L2, and the corresponding sixth tangential vector is This third maximum control point S must fall on the circumferential circle where the outer contour of the fan blade 100 is located, so that the radial position of the third maximum control point S on the fan blade 100 is known. Its axial position should be within the width range of the hub 110, and the circumferential position should be clamped between the fifth control point S3 and the sixth control point P3. Therefore, from the known fifth control point S3 and sixth control point P3, their corresponding tangent vectors, and the position range of the third maximum control point S, n + 1 d-order B-spline curve control points are obtained.

[0077]

[0078] Among them, N i,d (u) is the basis function of the d-order B-spline curve.

[0079]

[0080]

[0081] Thus, a smooth curve is obtained through the above B-spline curve fitting, and this curve is the third contour boundary 124c of the bridging segment 124.

[0082] The seventh control point P4 is the point on the first pressure side 125b where the distance to the first trailing edge 125d is 1% L1, corresponding to the seventh tangential vector The eighth control point S4 is the point on the second suction side 126a where the distance to the second trailing edge 126d is 1% L2, corresponding to the eighth tangential vector The fourth maximum control point S' must fall on the circumference with a radius of R1 - Tte, so that the radial position of the third maximum control point S' in the fan blade 100 is known. Its axial position should be within the width range of the hub 110, and its circumferential position should be clamped between the seventh control point P4 and the eighth control point S4. Therefore, from the known seventh control point P4, eighth control point S4 and their corresponding tangent vectors, as well as the position range of the fourth maximum control point S', a smooth curve is obtained again through d-order B-spline curve fitting. This curve is the fourth contour boundary 124d of the bridging segment 124. The third contour boundary 124c and the fourth contour boundary 124d jointly define the rear contour of the bridging segment 124, thus precisely controlling the rear contour of the bridging segment 124, ensuring the smooth connection of the leading edge of the blade 120, and then controlling the air flow velocity flowing out of the hollow region 121, and further reducing noise. And the first contour boundary 124a, the second contour boundary 124b, the third contour boundary 124c and the fourth contour boundary 124d jointly define the bridging segment 124. Thus, precise geometric control of the surface of the bridging segment 124 is achieved, the flow area and angle in the hollow region 121 are controlled, and then the air flow velocity in the hollow region 121 is controlled. It can also further reduce the tip vortex at the tip of the blade 110 of the fan blade 100, thereby reducing the noise of the fan blade 100. On the other hand, it can also improve the work capacity of the fan blade 100.

[0083] Among them, the distance between the fifth control point S3 and the seventh control point P4 is T1te, and the distance between the sixth control point P3 and the eighth control point S4 is T2te. Generally, Tte, T1te and T2te satisfy T1te ≤ Tte ≤ T2te.

[0084] In an embodiment, the outer contour of the fan blade 100 has a first radius R1. Using a cylinder with a radius of r1 as the reference cylinder surface 200, where 0.9R1 ≤ r1 ≤ 0.95R1, the reference cylinder surface 200 cuts the first segment 122 to form the first cross-section 125, and the reference cylinder surface 200 cuts the second segment 123 to form the second cross-section 126. When the reference cylinder surface 200 is unfolded flat, the included angle between the first extension line of the pressure side of the first cross-section 125 and the second extension line of the suction side of the second cross-section 126 is βth; and 10° ≤ βth ≤ 30°. Specifically, the radius r1 of the reference cylinder surface 200 satisfies 0.9R1 ≤ r1 ≤ 0.95R1, that is, the reference cylinder surface 200 cuts the outer end (tip) of the blade 120, so that the reference cylinder surface 200 cuts the first segment 122 to obtain the first cross-section 125, and the reference cylinder surface 200 cuts the second segment 123 to obtain the second cross-section 126, and the reference cylinder surface 200 is unfolded flat. Correspondingly, the first cross-section 125 and the second cross-section 126 are unfolded flat on the reference cylinder surface 200. The first pressure side 125b has a first extension line extending in the direction close to the second cross-section 126, and the corresponding second suction side 126a has a second extension line extending in the direction close to the first cross-section 125. The first extension line and the second extension line intersect, and the included angle between them is βth, and 10° ≤ βth ≤ 30°. Thereby, the angle control of the airflow flowing through the hollow region 121 is realized, so that the airflow vortex at the trailing edge of the suction surface of the first segment 122 can flow to the suction surface of the second segment 123. In this way, the airflow vortex at the trailing edge of the suction surface of the first segment 122 can be absorbed by the second segment 123, reducing the tip vortex at the tip of the blade 110, thereby reducing the noise of the fan blade 100. On the other hand, it can also improve the work capacity of the fan blade 100.

[0085] Further, referring to Figure 5 、 Figure 6 and Figure 9 , the first cross-section 125 has a first chord length L1. The suction side of the first cross-section 125 has a fifth control point, and the pressure side of the first cross-section 125 also has a seventh control point. The distances from the fifth control point and the seventh control point to the trailing edge of the first cross-section 125 are both 1%L1. The distance between the fifth control point and the seventh control point is T1te, and the distance from the seventh control point to the second extension line is Wth;

[0086] The second cross-section 126 has a second chord length L2. The pressure side of the second cross-section 126 has a second control point, and the suction side of the second cross-section 126 has a fourth control point. The distances from the second control point and the fourth control point to the leading edge of the second cross-section 126 are both 1%L2. The distance between the second control point and the fourth control point is T2le;

[0087] If 0 ≤ Wth ≤ min(T1te, T2le), the chord length of the outer end of the first segment 122 is greater than the chord length of the outer end of the second segment 123;

[0088] If Wth ≥ T1te + T2le, the chord length of the outer end of the first segment 122 is equal to the chord length of the outer end of the second segment 123.

[0089] Specifically, the first cross-section 125 has a first chord length L1 (the length formed by connecting the first leading edge 125c and the first trailing edge 125d), the second cross-section 126 has a second chord length L2 (the length formed by connecting the first leading edge 125c and the first trailing edge 125d), the fifth control point S3 is the point on the first suction side 125a with a distance of 1%L1 from the first trailing edge 125d, the seventh control point P4 is the point on the first pressure side 125b with a distance of 1%L1 from the first trailing edge 125d, and the distance between the fifth control point S3 and the seventh control point P4 is T1te, that is, the thickness of the rear end of the first segment 122 is T1te. The second control point P1 is the point on the second pressure side 126b with a distance of 1%L2 from the second leading edge 126c, the fourth control point S2 is the point on the second suction side 126a with a distance of 1%L2 from the second leading edge 126c, and the distance between the second control point and the fourth control point is T2le, that is, the thickness of the front end of the second segment 123 is T2le;

[0090] It should be noted that the extension lines of the distance between the fifth control point S3 and the seventh control point P4 intersect with the first extension line and the second extension line respectively, so as to obtain a line segment between the first extension line and the second extension line, and the length of this line segment is the distance Wth from the seventh control point P4 to the second extension line.

[0091] Refer to Figure 5 and Figure 6 When 0 ≤ Wth ≤ min(T1te, T2le), at this time, the distance between the first cross-section 125 and the second cross-section 126 is relatively close, that is, the throat width of the hollow region 121 between the first segment 122 and the second segment 123 is relatively small. Therefore, the chord length of the outer end of the first segment 122 is greater than the chord length of the outer end of the second segment 123, that is, the width of the first segment 122 is greater than the width of the second segment 123, so as to obtain a better solution for the relative position relationship and corresponding dimensions between the outer ends of the first segment 122 and the second segment 123, further reducing the tip vortex at the blade tip of the blade 110, thereby reducing the noise of the fan blade 100. On the other hand, it can also improve the work capacity of the fan blade 100.

[0092] Refer to Figure 9, when Wth≥T1te+T2le, the distance between the first cross-section 125 and the second cross-section 126 is relatively large at this time, that is, the throat width of the hollow region 121 between the first segment 122 and the second segment 123 is relatively large. Therefore, the chord length of the outer end of the first segment 122 is equal to the chord length of the outer end of the second segment 123, that is, the width of the first segment 122 is equal to the width of the second segment 123. Thus, a better solution for the relative position relationship and corresponding dimensions between the outer ends of the first segment 122 and the second segment 123 is obtained, further reducing the tip vortex at the blade tip of the blade 110, thereby reducing the noise of the fan blade 100. On the other hand, it can also improve the work capacity of the fan blade 100.

[0093] In one embodiment, referring again to Figure 5 and Figure 9 , the outer contour of the fan blade 100 has a first radius R1. Using a cylinder with a radius of r1 as the reference cylinder surface 200, satisfying 0.9R1≤r1≤0.95R1, the reference cylinder surface 200 cuts the first segment 122 to form the first cross-section 125, and the reference cylinder surface 200 cuts the second segment 123 to form the second cross-section 126;

[0094] Both the first cross-section 125 and the second cross-section 126 are convexly provided in a direction away from the air intake direction of the fan blade 100.

[0095] Specifically, the radius r1 of the reference cylinder surface 200 satisfies 0.9R1≤r1≤0.95R1, that is, the reference cylinder surface 200 cuts the outer end (blade tip) of the blade 120, so that the reference cylinder surface 200 cuts the first segment 122 to obtain the first cross-section 125, and the reference cylinder surface 200 cuts the second segment 123 to obtain the second cross-section 126. Both the first cross-section 125 and the second cross-section 126 are convexly provided in a direction away from the air intake direction of the fan blade 100, that is, both the first cross-section 125 and the second cross-section 126 adopt a positive camber, that is, the outer ends of both the first segment 122 and the second segment 123 are recessed relative to the front of the fan blade 100. In this way, on the one hand, the work capacity of the fan blade 100 can be improved, and on the other hand, it can also reduce the possibility of the airflow separating at the first trailing edge due to an excessive angle of attack (the angle formed by the chord length direction of the first segment 122 and / or the second segment 123 and the oncoming airflow), resulting in the stall of the fan blade 100.

[0096] In another embodiment, referring to Figure 6 , the outer contour of the fan blade 100 has a first radius R1. Using a cylinder with a radius of r1 as the reference cylinder surface 200, satisfying 0.9R1≤r1≤0.95R1, the reference cylinder surface 200 cuts the first segment 122 to form the first cross-section 125, and the reference cylinder surface 200 cuts the second segment 123 to form the second cross-section 126;

[0097] The first cross-section 125 is convexly arranged in the air intake direction away from the fan blade 100, and the second cross-section 126 is convexly arranged along the air intake direction of the fan blade 100.

[0098] Specifically, the radius r1 of the reference cylindrical surface 200 satisfies 0.9R1 ≤ r1 ≤ 0.95R1, that is, the reference cylindrical surface 200 cuts the outer end (blade tip) of the blade 120, so that the reference cylindrical surface 200 cuts the first segment 122 to obtain the first cross-section 125, and the reference cylindrical surface 200 cuts the second segment 123 to obtain the second cross-section 126. The first cross-section 125 is convexly arranged in the air intake direction away from the fan blade 100, and the second cross-section 126 is convexly arranged along the air intake direction of the fan blade 100, that is, the first cross-section 125 adopts a positive camber, and the second cross-section 126 adopts a negative camber, that is, the outer end of the first segment 122 is recessed relative to the front of the fan blade 100, and the outer end of the second segment 123 is convex relative to the front of the fan blade 100. The first cross-section 125 adopts a positive camber, that is, the outer ends of both the first segment 122 and the second segment 123 are recessed relative to the front of the fan blade 100. In this way, on the one hand, the work capacity of the fan blade 100 can be improved, and on the other hand, the possibility of the airflow separating at the first trailing edge due to an excessive angle of attack (the angle between the chord direction of the first segment 122 and the oncoming airflow), resulting in the stall of the fan blade 100, can be reduced. The second cross-section 126 adopts a negative camber, so that the second segment 123 can effectively absorb the trailing edge energy of the first segment 122, thereby reducing the intensity of the trailing vortex and being beneficial to reducing noise.

[0099] The present invention also provides a fan, including a fan blade 100 and a driving member connected to the fan blade 100, and the driving member is used to drive the fan blade 100 to rotate. The specific structure of the fan blade 100 refers to the above embodiments. Since this fan adopts all the technical solutions of the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be elaborated here one by one. Among them, this fan can specifically be an axial flow fan with an axial flow fan blade 100, and the driving member can specifically adopt a driving motor.

[0100] The present invention also provides a blowing device, including a fan blade 100 or a fan. The specific structure of the fan blade 100 or the fan refers to the above embodiments. Since this blowing device adopts all the technical solutions of the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be elaborated here one by one. Among them, this blowing device includes, but is not limited to, fan products such as floor fans, ceiling fans, and table fans. This blowing device can also be other devices with an axial flow fan blade 100 (such as the outdoor unit of an air conditioner). By adopting the above fan blade 100 or fan, the noise of the blowing device can be effectively reduced, and the user experience can be improved.

[0101] The above are only the preferred embodiments of the present invention, and do not thereby limit the patent scope of the present invention. Any equivalent structural transformation made under the inventive concept of the present invention by using the content of the specification and drawings of the present invention, or any direct / indirect application in other related technical fields is included in the patent protection scope of the present invention.

Claims

1. A fan blade, characterized in that, Comprising: A hub; Blades, connected to the hub, the blades including a first segment, a second segment, and a bridging segment connecting the outer ends of the first segment and the second segment, at least part of the first segment and the second segment being spaced apart circumferentially and / or axially from the hub, a hollow region being defined between the first segment, the bridging segment, and the second segment, and the first segment, the bridging segment, and the second segment smoothly transitioning, the outer contour line of the bridging segment being formed by curve fitting.

2. The fan blade according to claim 1, characterized in that, The outer contour of the fan blade has a first radius R1. Taking a cylinder with a radius of r1 as a reference cylinder surface, satisfying 0.9R1 ≤ r1 ≤ 0.95R1, the reference cylinder surface cuts the first segment to form a first cross-section. The first cross-section has a first chord length L1. The suction side of the first cross-section has a first control point, and the distance from the first control point to the leading edge of the first cross-section is 1%L1; The reference cylinder surface cuts the second segment to form a second cross-section. The second cross-section has a second chord length L2. The pressure side of the second cross-section has a second control point, and the distance from the second control point to the leading edge of the second cross-section is 1%L2; From the first radius R1, a first maximum control point is obtained. The first control point has a first vector, and the second control point has a second vector. By spline curve fitting, the first contour boundary of the bridging segment is obtained; The pressure side of the first cross-section has a third control point, and the distance from the third control point to the leading edge of the first cross-section is 1%L1; the suction side of the second cross-section has a fourth control point, and the distance from the fourth control point to the leading edge of the second cross-section is 1%L2; The leading edge of the bridging segment has a first preset thickness Tle. From the first maximum control point and the first preset thickness Tle, a second maximum control point is obtained. The third control point has a third vector, and the fourth control point has a fourth vector. By spline curve fitting, the second contour boundary of the bridging segment is obtained. The first contour boundary and the second contour boundary jointly define the front-end contour of the bridging segment.

3. The fan blade according to claim 2, characterized in that The suction side of the first cross-section further has a fifth control point, and the distance from the fifth control point to the trailing edge of the first cross-section is 1%L1; the pressure side of the second cross-section further has a sixth control point, and the distance from the sixth control point to the trailing edge of the second cross-section is 1%L2; From the first radius R1, a third maximum control point is obtained. The fifth control point has a fifth vector, and the sixth control point has a sixth vector. By spline curve fitting, the third contour boundary of the bridging segment is obtained; The pressure side of the first cross-section further has a seventh control point, and the distance from the seventh control point to the trailing edge of the first cross-section is 1%L1; the suction side of the second cross-section has an eighth control point, and the distance from the eighth control point to the trailing edge of the second cross-section is 1%L2; The trailing edge of the bridging segment has a second preset thickness Tte. A fourth maximum control point is obtained from the third maximum control point and the second preset thickness Tte. The seventh control point has a seventh vector, and the eighth control point has an eighth vector. The fourth contour boundary of the bridging segment is obtained by spline curve fitting. The fourth contour boundary and the third contour boundary jointly define the trailing end contour of the bridging segment, and the first contour boundary, the second contour boundary, the third contour boundary, and the fourth contour boundary jointly define the bridging segment.

4. The fan blade according to claim 1, characterized in that, The outer contour of the fan blade has a first radius R1. A reference cylindrical surface with a radius of r1 is used, satisfying 0.9R1 ≤ r1 ≤ 0.95R1. The reference cylindrical surface cuts the first segment to form a first cross-section, and the reference cylindrical surface cuts the second segment to form a second cross-section. The reference cylindrical surface is unfolded in a plane. The included angle between the first extension line of the pressure side of the first cross-section and the second extension line of the suction side of the second cross-section is βth, and 10° ≤ βth ≤ 30°.

5. The fan blade according to claim 4, characterized in that, The first cross-section has a first chord length L1. The suction side of the first cross-section has a fifth control point, and the pressure side of the first cross-section also has a seventh control point. The distances from the fifth control point and the seventh control point to the trailing edge of the first cross-section are both 1%L1. The distance between the fifth control point and the seventh control point is T1te, and the distance from the seventh control point to the second extension line is Wth. The second cross-section has a second chord length L2. The pressure side of the second cross-section has a second control point, and the suction side of the second cross-section has a fourth control point. The distances from the second control point and the fourth control point to the leading edge of the second cross-section are both 1%L2. The distance between the second control point and the fourth control point is T2le. If 0 ≤ Wth ≤ min(T1te, T2le), the chord length of the outer end of the first segment is greater than the chord length of the outer end of the second segment. If Wth ≥ T1te + T2le, the chord length of the outer end of the first segment is equal to the chord length of the outer end of the second segment.

6. The fan blade according to claim 1, wherein, The outer contour of the fan blade has a first radius R1. A reference cylindrical surface with a radius of r1 is used, satisfying 0.9R1 ≤ r1 ≤ 0.95R1. The reference cylindrical surface cuts the first segment to form a first cross-section, and the reference cylindrical surface cuts the second segment to form a second cross-section. Both the first cross-section and the second cross-section protrude away from the air intake direction of the fan blade; or, The first cross-section protrudes away from the air intake direction of the fan blade, and the second cross-section protrudes along the air intake direction of the fan blade.

7. The fan blade according to claim 1, characterized in that, The inner end of the first segment and the inner end of the second segment are respectively connected to the hub. Or, the inner end of the first segment is connected to the side edge of the second segment, and the inner end of the second segment is connected to the hub. Or, the inner ends of the first segment and the second segment are connected to each other and are simultaneously connected to the hub.

8. The fan blade according to any one of claims 1 to 7, characterized in that, There are N blades provided on the hub, and 2 ≤ N ≤ 9.

9. A fan, characterized in that, Comprising a fan blade according to any one of claims 1 to 8, and a driving member connected to the fan blade, the driving member being configured to drive the fan blade to rotate.

10. A hair dryer device, characterized in that, Comprising a fan blade according to any one of claims 1 to 8 or a fan according to claim 9.

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