Fan blade, fan and blowing equipment

Abstract

The utility model discloses a fan blade, fan and blowing equipment, the fan blade comprises a hub and a blade, the blade is connected with the hub, the blade comprises a first segment, a second segment and a bridging segment, the bridging segment is 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, noise generated when the fan blades operate can be effectively reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of blowing equipment, in particular to a fan blade, a fan and blowing equipment. Background Art

[0002] Blowing equipment is widely used in people's daily life. Among them, blowing equipment with axial flow fan blades (such as floor fans) is favored by many users because of its strong wind force and wide blowing range. The existing blowing equipment with axial flow fan blades mainly adopts a structure in which multiple solid blades extend from the hub. When the blowing equipment is turned on a larger gear, the noise is often relatively loud, which will cause certain troubles to users. At present, some blowing equipment usually makes some bionic shape structures at the tail of the blade to reduce noise, but the noise reduction effect is limited. Therefore, it is urgent to adopt other solutions to effectively reduce the noise when the fan blades are running. Utility Model Content

[0003] The main purpose of the utility model is to provide a fan blade, which is intended to effectively reduce the noise when the fan blade is running.

[0004] In order to achieve the above-mentioned purpose, the fan blade proposed by the utility model includes:

[0005] Wheel hub;

[0006] A blade is connected to the hub, the blade comprising a first segment, a second segment and a bridging segment connecting the outer end of the first segment and the outer end of the second segment, at least parts of the first segment and the second segment are spaced apart in the circumferential and / or axial direction of the hub, a hollow area is enclosed between the first segment, the bridging segment and the second segment, and there is a smooth transition between the first segment, the bridging segment and the second segment, and 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, and a cylinder with a radius of r1 is used as a reference cylindrical surface, satisfying 0.9R1≤r1≤0.95R1, and the reference cylindrical surface cuts the first segment to form a first cross section, the first cross section has a first chord length L1, and 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;

[0008] The reference cylindrical 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;

[0009] A first maximum control point is obtained from the first radius R1, the first control point has a first vector, the second control point has a second vector, and a first contour boundary of the bridge segment is obtained through 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, a second maximum control point is obtained by the first maximum control point and the first preset thickness Tle, the third control point has a third vector, the fourth control point has a fourth vector, and the second contour boundary of the bridging segment is obtained by spline curve fitting, and 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, and 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] A third maximum control point is obtained from the first radius R1, the fifth control point has a fifth vector, the sixth control point has a sixth vector, and a third contour boundary of the bridge segment is obtained through spline curve fitting;

[0014] The pressure side of the first section also 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, a fourth maximum control point is obtained by the third maximum control point and the second preset thickness Tte, the seventh control point has a seventh vector, the eighth control point has an eighth vector, and a 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, and a cylinder with a radius r1 is used as a reference cylindrical surface, satisfying 0.9R1≤r1≤0.95R1, the reference cylindrical surface cuts the first segment to form a first section, and the reference cylindrical surface cuts the second segment to form a second section, and the reference cylindrical surface plane is unfolded, and the angle between the first extension line of the pressure side of the first section and the second extension line of the suction side of the second section is βth; and satisfies 10°≤βth≤30°.

[0017] Optionally, the first section has a first chord length L1, the suction side of the first section has a fifth control point, the pressure side of the first section further has a seventh control point, the distances from the fifth control point and the seventh control point to the trailing edge of the first 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, a second control point is provided on the pressure side of the second cross section, a fourth control point is provided on the suction side of the second cross section, 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, and the distance between the second control point and the fourth control point is T2le;

[0019] If 0≤Wth≤min(T1te, T2le) is satisfied, 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 is satisfied, 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, and a cylinder with a radius of r1 is used as a 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] The first cross section and the second cross section are both convexly arranged away from the air intake direction of the fan blade; or,

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

[0024] Optionally, the inner end of the first segment and the inner end of the second segment are respectively connected to the hub, and the first segment, the second segment and the outer side surface of 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 wheel hub;

[0026] Alternatively, the inner end of the first segment is connected to the inner end of the second segment and is also connected to the hub.

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

[0028] The utility model also provides a fan, comprising the fan blades as described above, and a driving member connected to the fan blades, wherein the driving member is used to drive the fan blades to rotate.

[0029] The utility model also provides a blowing device, characterized in that it comprises the fan blades as described above or the fan as described above.

[0030] The technical solution of the utility model is to arrange blades on the hub, and the blades include a first segment, a second segment and a bridge segment connecting the outer end of the first segment and the outer end of the second segment. At least part of the first segment and the second segment are arranged at intervals in the circumferential direction and / or axial direction of the hub. The hollow area is defined by the first segment, the bridge segment, the second segment and the hub. In the rotation direction of the fan blade, the first segment is located upstream of the second segment. When the fan blade rotates, most of the airflow can be directly blown out positively by the pressure surface 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, so that the airflow vortex at the trailing edge of the first segment can be absorbed by the second segment, reducing the possibility of the airflow vortex at the tail of the first segment directly falling off and generating a large noise, thereby effectively reducing the noise of the fan blade. The first segment, the second segment and the bridge segment jointly define the hollow area, and the three smoothly transition, so that the fan shape is smooth, which can reduce the resistance of the airflow flowing along the hollow area, thereby further reducing the noise. The outer contour line of the bridge segment is formed by curve fitting, and the boundary contour of the bridge segment is obtained through multiple curve fittings, and then the shape of the bridge segment is obtained, thereby realizing precise geometric control of the curved surface of the bridge segment, realizing control of the flow area and angle of the flow through the hollow area, and then controlling the air flow velocity in the hollow area, and can also further reduce the wingtip vortex at the top of the blade, thereby reducing the noise of the fan blade, and on the other hand, it can also improve the working capacity of the fan blade. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0032] Figure 1 This is a schematic structural diagram of the first embodiment of the fan blade of the utility model;

[0033] Figure 2 This is a schematic structural diagram of a second embodiment of the fan blade of the utility model;

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

[0035] Figure 4 for Figure 3 A partial enlarged view of the first section and the second section;

[0036] Figure 5 for Figure 2 A planar development diagram of the first section and the second section;

[0037] Figure 6 It is a planar development diagram of the first cross section and the second cross section in the third embodiment of the fan blade of the utility model;

[0038] Figure 7 This is a schematic structural diagram of a fourth embodiment of the fan blade of the utility model;

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

[0040] Fig. 9 for Figure 8 A planar development diagram of the first section and the second section;

[0041] Fig.10 This is a schematic structural diagram of the fifth embodiment of the fan blade of the utility model;

[0042] Fig.11 It is a structural schematic diagram of the sixth embodiment of the fan blade of the utility model.

[0043] Description of Figure Numbers:

[0044] Label name Label name 100 Fan blade 125 First section 110 Wheels 125a First suction side 120 blade 125b First pressure side 121 Hollow area 125c First leading edge 122 First Clip 125d First trailing edge 123 Second segment 126 Second section 124 Bridge Clip 126a Second suction side 124a First contour boundary 126b Second pressure side 124b Second contour boundary 126c Second leading edge 124c Third contour boundary 126d The second trailing edge 124d Fourth contour boundary 200 Reference cylindrical surface

[0045] The realization of the purpose, functional features and advantages of the utility model will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0046] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

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

[0048] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the utility model, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the meaning of "and / or" appearing in the full text is to include three parallel solutions, taking "A and / or B as an example", including solution A, or solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in this field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the utility model.

[0049] The utility model provides a fan blade 100.

[0050] In the embodiment of the present utility model, Figures 1 to 11 As shown, the fan blade 100 includes a hub 110 and a blade 120, and the blade 120 is connected to the hub 110. The blade 120 includes a first segment 122, a second segment 123 and a bridging segment 124 connecting the outer end of the first segment 122 and the outer end of the second segment 123. At least parts 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 area 121 is enclosed between the first segment 122, the bridging segment 124 and the second segment 123, and there is a smooth transition between 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, refer to Figure 1 , Figure 2 , Figure 7 , Fig.10 and Fig.11 The fan blade 100 includes a hub 110 and N blades 120 arranged on the periphery of the hub 110, wherein the number of blades 120 can be set according to actual needs, and is 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 following mainly describes the structure of a single blade 120, and the structures of other blades 120 are the same or similar to the structure of the blade 120. The inner end (root) of the blade 120 is connected to the hub 110, and there can be many ways to connect it. For example, the blade 120 and the hub 110 can be integrally formed, or they can be assembled together by assembly structures such as screws and snaps, which are not specifically limited here.

[0052] It is understandable that part of the noise of the current traditional axial flow fan blade 100 comes from the shedding vortex formed at the tail of the blade 120 when the fan blade 100 rotates. That is, when the fan blade 100 rotates, the airflow will form an airflow vortex at the tail of the blade 120, and the airflow vortex will directly fall off from the trailing edge of the blade 120, which will produce a large noise, resulting in a large noise when the entire fan blade 100 is running, causing trouble to the user and affecting the user's experience. In this solution, a hollow area 121 is formed on the blade 120, and the hollow area 121 has a certain guiding effect on the airflow on the blade 120. When the fan blade 100 rotates, the airflow 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 airflow vortex at the trailing edge of the fan blade 100 can be dispersed to prevent the airflow vortex from directly detaching from the trailing edge of the blade 120 and generating a large shedding vortex noise, thereby achieving a good noise reduction effect, effectively reducing the noise generated when the fan blade 100 is running, and improving the user experience.

[0053] In this embodiment, refer to Figure 1 , Figure 2 and Figure 7The blade 120 includes a first segment 122, a second segment 123 and a bridging segment 124 connecting the outer end of the first segment 122 and the outer end of the second segment 123. At least parts of the first segment 122 and the second segment 123 are spaced apart in the circumferential and / or axial direction of the hub 110, and there is a smooth transition between the first segment 122, the bridging segment 124 and the second segment 123, and together define a hollow area 121. Specifically, the first segment 122, the bridging segment 124 and the second segment 123 are together enclosed to form an annular structure, the hollow area 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 in the circumferential direction and / or axial direction of the hub 110, that is, at least part of the first segment 122 and the second segment 123 can be spaced apart only in the axial direction of the hub 110, at which time the first segment 122 and the second segment 122 are arranged opposite to each other in the axial direction of the hub 110, and have a certain thickness corresponding to the hollow area 121, or can be spaced apart only in the circumferential direction of the hub 110, at which time the first segment 122 and the second segment 122 are arranged opposite to each other in the circumferential direction of the hub 110, and have a certain width corresponding to the hollow area 121, or at least part of the first segment 122 and the second segment 123 are spaced apart in both the axial and circumferential directions of the hub 110, at which time the first segment 122 and the second segment 123 are staggered in the hub 110.

[0054] There are many specific construction methods for the hollow area 121. In one embodiment, the inner end of the first segment 122 and the inner end of 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 blades on the hub 110, so that the first segment 122, the second segment 123 and the hub 110 are enclosed together to form an annular structure. In this way, the effective length of the first segment 122 and the second segment 123 can be increased, thereby improving the total working 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 away from the hub 110, that is, the inner end of the blade 120 corresponds to the root of the blade, and the outer end of the blade 120 corresponds to the tip of the blade.

[0055] In another embodiment, the hollow area 122 may also be directly opened on the blade 120 body and disposed close to the outer end of the blade 120. Fig.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 Fig.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 end of the first segment 122 and the inner end of the second segment 123 are respectively connected to the hub 110, and the first segment 122, the bridge segment 124, the second segment 123 and the hub 110 jointly define a hollow area 121. Specifically, 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 airflow can be directly blown out in a positive direction by the pressure surface 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, so that 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 a large noise, thereby effectively reducing the noise of the fan blade 100. The bridge segment 124 connects the outer end of the first segment 122 and the outer end of the second segment 123, and the first segment 122, the bridge segment 124 and the second segment 123 have a smooth transition, and together with the hub 110 define a hollow area 121. The first segment 122, the second segment 123 and the bridge segment 124 enclose a hollow area 121, and the three have a smooth transition, making the fan-shaped smooth, which can reduce the resistance of the airflow flowing along the hollow area 121, thereby further reducing noise. The outer contour line of the bridging segment 124 is formed by curve fitting, and the boundary contour of the bridging segment 124 is obtained by multiple curve fittings, and then the shape of the bridging segment 124 is obtained, thereby achieving precise geometric control of the curved surface of the bridging segment 124, and achieving control of the flow area and angle of the flow through the hollow area 121, thereby controlling the air flow velocity in the hollow area 121, and can further reduce the wingtip vortex at the top of the blade 110, thereby reducing the noise of the fan blade 100, and on the other hand, can also improve the working capacity of the fan blade 100.

[0058] In one embodiment, the first segment 122, the second segment 123 and the bridge segment 124 are integrally formed, so that the overall structural strength of the blade 120 is higher and the stability is better, and the manufacturing process can also be simplified. The hollow area 121 can also reduce the weight of the blade 120, thereby reducing the overall weight of the fan blade 100, so that 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 set in the hollow area 121, which can also play a role in filtering and purification.

[0059] The technical solution of the utility model is to arrange the blade 120 on the hub 110, and the blade 120 includes a first segment 122, a second segment 123 and a bridge segment 124 connecting the outer end of the first segment 122 and the outer end of the second segment 123. At least part of the first segment 122 and the second segment 123 are arranged at intervals in the circumferential direction and / or axial direction of the hub 110. The hollow area 121 is defined by the first segment 122, the bridge 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 airflow can be directly blown out in the positive direction by 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, so that the airflow vortex at the trailing edge of the first segment 122 can be absorbed by the second segment 123, reducing the possibility of the airflow vortex at the tail of the first segment 122 directly falling off and generating a large noise, thereby effectively reducing the noise of the fan blade 100. The first segment 122, the second segment 123 and the bridge segment 124 jointly define the hollow area 121, and the three smoothly transition, making the fan shape smooth, which can reduce the resistance of the airflow flowing along the hollow area 121, thereby further reducing the noise. The outer contour line of the bridging segment 124 is formed by curve fitting, and the boundary contour of the bridging segment 124 is obtained by multiple curve fittings, and then the shape of the bridging segment 124 is obtained, thereby achieving precise geometric control of the curved surface of the bridging segment 124, and achieving control of the flow area and angle of the flow through the hollow area 121, thereby controlling the air flow velocity in the hollow area 121, and can further reduce the wingtip vortex at the top of the blade 110, thereby reducing the noise of the fan blade 100, and on the other hand, can also improve the working capacity of the fan blade 100.

[0060] Reference Figures 1 to 9 In one embodiment, the outer contour of the fan blade 100 has a first radius R1, and a cylinder with a radius of r1 is used as a reference cylindrical surface 200, satisfying 0.9R1≤r1≤0.95R1, and the reference cylindrical surface 200 cuts the first segment 122 to form a first section 125, and the first section 125 has a first chord length L1, and the suction side of the first section 125 has a first control point, and the distance from the first control point to the leading edge of the first section 125 is 1% L1;

[0061] The second segment 123 is cut with reference to the cylindrical surface 200 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] A first maximum control point is obtained from the first radius R1, the first control point has a first vector, the second control point has a second vector, and a first contour boundary 124a of the bridge segment 124 is obtained through spline curve fitting;

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

[0064] The leading edge of the bridging segment 124 has a first preset thickness Tle, the second maximum control point is obtained by the first maximum control point and the first preset thickness Tle, the third control point has a third vector, the fourth control point has a fourth vector, and the second contour boundary 124b of the bridging segment 124 is obtained by spline curve fitting. 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 explanation, the suction surface of the blade 120 is the suction side of the first section 125, which is the side where the suction surface of the first segment 122 is located, temporarily set as the first suction side 125a, the pressure side of the first 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 section 126 is the side where the suction surface of the second segment 123 is located, temporarily set as the second suction side 126a, and the pressure side of the first 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 section 125 is the edge where the airflow begins to enter the first segment 122, temporarily set as the first leading edge 125c, and the leading edge of the second section 126 is the edge where the airflow begins to enter the second segment 123, temporarily set as the second leading edge 126c, refer to Figure 6 and Fig. 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 tangent vector be The second tangent vector is The third tangent vector is The fourth tangent vector is Reference 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 section 125, and the reference cylindrical surface 200 cuts the second segment 123 to obtain the second section 126. 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). Figure 5 , Figure 6 and Fig. 9 The first control point S1 is a point on the first suction side 125a at a distance of 1% L1 from the first leading edge 125c, corresponding to the first tangent vector The second control point P1 is a point on the second pressure side 126b at a distance of 1% L2 from the second leading edge 126c, corresponding to the second tangent vector The first maximum control point P must fall on the circumference of the outer contour of the blade 100, so that the radial position of the first maximum control point P on the blade 100 is known, its axial position should be within the width range of the hub 110, and the circumferential position should be sandwiched between the first control point S1 and the second control point P1. Therefore, from the known points of the first control point S1, the second control point P1, and 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] Among them, N i,d (u) is the primitive function of the d-order B-spline curve.

[0068]

[0069]

[0070] Thus, a smooth curve is obtained through the B-spline curve fitting, and the curve is the first contour boundary 124 a of the bridge segment 124 .

[0071] Refer again Figures 4 to 9 The third control point P2 is a point on the first pressure side 125b at a distance of 1% L1 from the first leading edge 125c, corresponding to the third tangent vector The fourth control point S2 is a point on the second suction side 126a at a distance of 1% L2 from the second leading edge 126c, corresponding to the fourth tangent vector The second maximum control point P' must fall on the circumference of the circle with a radius of R1-Tle, so that the radial position of the second maximum control point P' in the fan blade 100 is known, its axial position should be located within the width range of the hub 110, and the circumferential position should be sandwiched between the third control point P2 and the fourth control point S2. Therefore, the known points of the third control point P2, the fourth control point S2, and their corresponding tangent vectors, and the position range of the second maximum control point P' are again fitted by a d-order B-spline curve to obtain a smooth curve. 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 end contour of the bridging segment 124, thereby forming precise control of the front end contour of the bridging segment 124, ensuring a smooth connection of the leading edge of the blade 120, and then controlling the airflow velocity entering the hollow area 121, thereby reducing noise.

[0072] 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. Figure 2 The pressure surface of the blade 120 is the side where the blade 120 moves relative to the airflow, that is, the direction of the airflow facing the blade. Correspondingly, the suction surface of the blade 120 refers to the other side where the blade 120 moves relative to the airflow, that is, the direction of the blade 120 facing away from the airflow.

[0073] Further, refer again to Figures 4 to 9 The suction side of the first section 125 also has a fifth control point, and the distance from the fifth control point to the trailing edge of the first section 125 is 1% L1. The pressure side of the second section 126 also has a sixth control point, and the distance from the sixth control point to the trailing edge of the second section 126 is 1% L2.

[0074] A third maximum control point is obtained from the first radius R1, a fifth control point has a fifth vector, and a sixth control point has a sixth vector, and a third contour boundary 124c of the bridge segment 124 is obtained through spline curve fitting;

[0075] The pressure side of the first section 125 also has a seventh control point, and the distance from the seventh control point to the trailing edge of the first section 125 is 1% L1; the suction side of the second section 126 has an eighth control point, and the distance from the eighth control point to the trailing edge of the second section 126 is 1% L2;

[0076] The trailing edge of the bridging segment 124 has a second preset thickness Tte, the fourth maximum control point is obtained by the third maximum control point and the second preset thickness Tte, the seventh control point has a seventh vector, the eighth control point has an eighth vector, and the fourth contour boundary 124d of the bridging segment 124 is obtained by spline curve fitting. The fourth contour boundary 124d and the third contour boundary 124c jointly define the rear end 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.

[0077] Specifically, for the convenience of explanation, the trailing edge of the first section 125 is the edge where the airflow flows out of the first segment 122, temporarily set as the first trailing edge 125d, and the trailing edge of the second section 126 is the edge where the airflow flows out of the second segment 123, temporarily set as the second trailing edge 126d, referring to Figure 6 and Fig. 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', and the fifth tangent vector be The sixth tangent vector is The seventh tangent vector is The eighth tangent vector is The fifth control point, S3, is a point on the first suction side 125a at a distance of 1% L1 from the first trailing edge 125d, and the corresponding fifth tangent vector is The sixth control point is P3, which is a point on the second pressure side 126b at a distance of 1% L2 from the second trailing edge 126d, and the corresponding sixth tangent vector is The third maximum control point S must fall on the circumference of the outer contour of the blade 100, so that the radial position of the third maximum control point S on the blade 100 is known, its axial position should be within the width range of the hub 110, and the circumferential position should be sandwiched between the fifth control point S3 and the sixth control point P3. Therefore, from the known points of the fifth control point S3 and the sixth control point P3, and 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.

[0078]

[0079] Among them, N i,d (u) is the primitive function of the d-order B-spline curve.

[0080]

[0081]

[0082] Thus, a smooth curve is obtained through the B-spline curve fitting, and the curve is the third contour boundary 124 c of the bridge segment 124 .

[0083] The seventh control point P4 is a point on the first pressure side 125b at a distance of 1% L1 from the first trailing edge 125d, corresponding to the seventh tangent vector The eighth control point S4 is a point on the second suction side 126a at a distance of 1% L2 from the second trailing edge 126d, corresponding to the eighth tangent vector The fourth maximum control point S' must fall on the circumference of the circle 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 located within the width range of the hub 110, and the circumferential position should be sandwiched between the seventh control point P4 and the eighth control point S4. Therefore, the known points of the seventh control point P4, the eighth control point S4 and their corresponding tangent vectors, and the position range of the fourth maximum control point S' are again fitted by a d-order B-spline curve to obtain a smooth curve. 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 end contour of the bridging segment 124, thereby forming precise control of the rear end contour of the bridging segment 124, ensuring a smooth connection of the leading edge of the blade 120, and then controlling the air flow velocity out of the hollow area 121, thereby reducing noise. The first contour boundary 124a, the second contour boundary 124b, the third contour boundary 124c and the fourth contour boundary 124d jointly define the bridge segment 124. Thus, precise geometric control of the curved surface of the bridge segment 124 is achieved, and the flow area and angle of the flow through the hollow area 121 are controlled, thereby controlling the air flow velocity in the hollow area 121, and further reducing the wing tip vortex of the blade top of the blade 110, thereby reducing the noise of the fan blade 100, and on the other hand, improving the work capacity of the fan blade 100.

[0084] 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.

[0085] In one embodiment, the outer contour of the fan blade 100 has a first radius R1, and a cylinder with a radius r1 is used as a reference cylindrical surface 200, satisfying 0.9R1≤r1≤0.95R1. The reference cylindrical surface 200 cuts the first segment 122 to form a first section 125, and the reference cylindrical surface 200 cuts the second segment 123 to form a second section 126. The reference cylindrical surface 200 is unfolded in a plane, and the angle between the first extension line of the pressure side of the first section 125 and the second extension line of the suction side of the second section 126 is βth; and 10°≤βth≤30° is satisfied. 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 section 125, and the reference cylindrical surface 200 cuts the second segment 123 to obtain the second section 126, and the reference cylindrical surface 200 is plane-unfolded, and the corresponding first section 125 and second section 126 are plane-unfolded on the reference cylindrical surface 200, and the first pressure side 125b has a first extension line extending in a direction close to the second section 126, corresponding to the second suction side 126. 6a has a second extension line extending in the direction close to the first section 125, and the first extension line intersects with the second extension line, and the angle between the two is βth, and 10°≤βth≤30°, thereby realizing the angle control of the airflow flowing through the hollow area 121, 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 wingtip vortex at the top of the blade 110, thereby reducing the noise of the fan blade 100, and on the other hand, it can also improve the working capacity of the fan blade 100.

[0086] Further, see Figure 5 , Figure 6 and Fig. 9 , the first section 125 has a first chord length L1, the suction side of the first section 125 has a fifth control point, the pressure side of the first 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 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;

[0087] The second section 126 has a second chord length L2, a second control point is provided on the pressure side of the second section 126, a fourth control point is provided on the suction side of the second section 126, the distances from the second control point and the fourth control point to the leading edge of the second section 126 are both 1%L2, and the distance between the second control point and the fourth control point is T2le;

[0088] If 0≤Wth≤min(T1te, T2le) is satisfied, 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;

[0089] If Wth≥T1te+T2le is satisfied, 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 .

[0090] Specifically, 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), 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), the fifth control point S3 is a point on the first suction side 125a at a distance of 1% L1 to the first trailing edge 125d, the seventh control point P4 is a point on the first pressure side 125b at a distance of 1% L1 to the first trailing edge 125d, 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 a point on the second pressure side 126b at a distance of 1% L2 from the second leading edge 126c, the fourth control point S2 is a point on the second suction side 126a at a distance of 1% L2 from the second leading edge 126c, 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;

[0091] It should be noted that the extension line of the distance between the fifth control point S3 and the seventh control point P4 intersects with the first extension line and the second extension line respectively, thereby obtaining a line segment between the first extension line and the second extension line, and the length of the line segment is the distance Wth from the seventh control point P4 to the second extension line.

[0092] Reference Figure 5 and Figure 6 , when 0≤Wth≤min(T1te, T2le), the distance between the first section 125 and the second section 126 is relatively close, that is, the throat width of the hollow area 121 between the first segment 122 and the second segment 123 is relatively small, so 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, thereby obtaining a better solution for the relative position relationship between the outer ends of the first segment 122 and the second segment 123 and their corresponding dimensions, so as to further reduce the wingtip vortex at the blade top of the blade 110, thereby reducing the noise of the fan blade 100, and on the other hand, it can also improve the working capacity of the fan blade 100.

[0093] Reference Fig. 9When Wth≥T1te+T2le, the distance between the first section 125 and the second section 126 is relatively far, that is, the throat width of the hollow area 121 between the first segment 122 and the second segment 123 is relatively large, so 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, thereby obtaining a better solution for the relative position relationship between the outer ends of the first segment 122 and the second segment 123 and their corresponding dimensions, so as to further reduce the wingtip vortex at the blade top of the blade 110, thereby reducing the noise of the fan blade 100, and on the other hand, it can also improve the working capacity of the fan blade 100.

[0094] In one embodiment, again referring to Figure 5 and Fig. 9 The outer contour of the fan blade 100 has a first radius R1, and a cylinder with a radius of r1 is used as a reference cylindrical surface 200, satisfying 0.9R1≤r1≤0.95R1. The reference cylindrical surface 200 cuts the first segment 122 to form a first section 125, and the reference cylindrical surface 200 cuts the second segment 123 to form a second section 126;

[0095] The first cross section 125 and the second cross section 126 are both convexly disposed away from the air intake direction of the fan blade 100 .

[0096] 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 top) of the blade 120, so that the reference cylindrical surface 200 cuts the first segment 122 to obtain the first section 125, and the reference cylindrical surface 200 cuts the second segment 123 to obtain the second section 126. The first section 125 and the second section 126 are both convexly arranged away from the air intake direction of the fan blade 100, that is, the first section 125 and the second section 126 both adopt positive camber, that is, the outer end of the first segment 122 and the outer end of the second segment 123 are both recessed relative to the front of the fan blade 100, so that on the one hand, the work capacity of the fan blade 100 can be improved, and on the other hand, the airflow separation at the first trailing edge caused by the excessively large angle of attack (the angle between the chord length direction of the first segment 122 and / or the second segment 123 and the oncoming airflow) can be reduced, resulting in the possibility of the fan blade 100 stalling.

[0097] In another embodiment, referring to Figure 6 The outer contour of the fan blade 100 has a first radius R1, and a cylinder with a radius of r1 is used as a reference cylindrical surface 200, satisfying 0.9R1≤r1≤0.95R1. The reference cylindrical surface 200 cuts the first segment 122 to form a first section 125, and the reference cylindrical surface 200 cuts the second segment 123 to form a second section 126;

[0098] The first section 125 is protruded away from the air inlet direction of the fan blade 100 , and the second section 126 is protruded along the air inlet direction of the fan blade 100 .

[0099] 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 top) of the blade 120, so that the reference cylindrical surface 200 cuts the first segment 122 to obtain the first section 125, and the reference cylindrical surface 200 cuts the second segment 123 to obtain the second section 126. The first section 125 is convexly arranged away from the air intake direction of the fan blade 100, and the second section 126 is convexly arranged along the air intake direction of the fan blade 100, that is, the first section 125 adopts a positive camber, and the second 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 convexly arranged relative to the front of the fan blade 100. The first section 125 adopts a positive camber, that is, the outer end of the first segment 122 and the outer end of the second segment 123 are both recessed relative to the front of the fan blade 100. This can improve the work capacity of the fan blade 100 on the one hand, and on the other hand, it can also reduce the possibility of the airflow separation at the first trailing edge caused by the excessive angle of attack (the angle between the chord length direction of the first segment 122 and the oncoming airflow), causing the fan blade 100 to stall. The second 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 trailing vortex intensity, which is conducive to reducing noise.

[0100] The utility model also proposes a fan, including a fan blade 100 and a driving member connected to the fan blade 100, wherein 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 embodiment. Since the fan adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated here. Among them, the fan can be specifically an axial flow fan with axial flow fan blades 100, and the driving member can specifically be a driving motor.

[0101] The utility model also proposes 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 embodiment. Since the blowing device adopts all the technical solutions of all the above embodiments, it at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated here. Among them, the blowing device includes but is not limited to fan products such as floor fans, ceiling fans, and desktop fans. The blowing device can also be other devices with axial flow fan blades 100 (such as air conditioner outdoor units). By adopting the above-mentioned fan blades 100 or fans, the noise of the blowing device can be effectively reduced and the user experience can be improved.

[0102] The above description is only a preferred embodiment of the utility model, and does not limit the patent scope of the utility model. All equivalent structural changes made by using the contents of the utility model specification and drawings under the utility model concept, or directly / indirectly used in other related technical fields are included in the patent protection scope of the utility model.

Claims

1. A fan blade, characterized in that: include: Wheel hub; A blade is connected to the hub, the blade comprising a first segment, a second segment and a bridging segment connecting the outer end of the first segment and the outer end of the second segment, at least parts of the first segment and the second segment are spaced apart in the circumferential and / or axial direction of the hub, a hollow area is enclosed between the first segment, the bridging segment and the second segment, and there is a smooth transition between the first segment, the bridging segment and the second segment, and the outer contour line of the bridging segment is 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, and a cylinder with a radius of r1 is used as a reference cylindrical surface, satisfying 0.9R1≤r1≤0.95R1. The reference cylindrical surface cuts the first segment to form a first cross section, the first cross section has a first chord length L1, and 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 cylindrical 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; A first maximum control point is obtained from the first radius R1, the first control point has a first vector, the second control point has a second vector, and a first contour boundary of the bridge segment is obtained through spline curve fitting; 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; The leading edge of the bridging segment has a first preset thickness Tle, a second maximum control point is obtained by the first maximum control point and the first preset thickness Tle, the third control point has a third vector, the fourth control point has a fourth vector, and the second contour boundary of the bridging segment is obtained by spline curve fitting, and 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 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; A third maximum control point is obtained from the first radius R1, the fifth control point has a fifth vector, the sixth control point has a sixth vector, and a third contour boundary of the bridge segment is obtained through spline curve fitting; The pressure side of the first section also 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; The trailing edge of the bridging segment has a second preset thickness Tte, a fourth maximum control point is obtained by the third maximum control point and the second preset thickness Tte, the seventh control point has a seventh vector, the eighth control point has an eighth vector, and a 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.

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

5. The fan blade according to claim 4, characterized in that: The first section has a first chord length L1, a fifth control point is provided on the suction side of the first section, and a seventh control point is provided on the pressure side of the first section. The distances from the fifth control point and the seventh control point to the trailing edge of the first 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, a second control point is provided on the pressure side of the second cross section, a fourth control point is provided on the suction side of the second cross section, 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, and the distance between the second control point and the fourth control point is T2le; If 0≤Wth≤min(T1te, T2le) is satisfied, 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 is satisfied, 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, characterized in that: The outer contour of the fan blade has a first radius R1, and a cylinder with a radius of r1 is used as a 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; The first cross section and the second cross section are both convexly arranged away from the air intake direction of the fan blade; or, The first section is protruded away from the air inlet direction of the fan blade, and the second section is protruded along the air inlet 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 wheel hub; 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 wheel hub; Alternatively, the inner end of the first segment is connected to the inner end of the second segment and is also connected to the hub.

8. The fan blade according to any one of claims 1 to 7, characterized in that: The hub is provided with N blades, and 2≤N≤9.

9. A fan, characterized in that: It comprises a fan blade as described in any one of claims 1 to 8, and a driving member connected to the fan blade, wherein the driving member is used to drive the fan blade to rotate.

10. A blowing device, characterized in that: It comprises the fan blade according to any one of claims 1 to 8 or the fan according to claim 9.

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