阅读说明：本技术 一种改良的离心风叶 (Improved centrifugal fan blade ) 是由 刘阳明 覃万翔 陆家伦 罗伟乐 刘爱瑜 王汉波 于 2020-11-03 设计创作，主要内容包括：一种改良的离心风叶,包括底盘和环形分布在底盘上的若干叶片,叶片包括叶片主体和在叶片主体一端向外延伸的延伸部,叶片主体所在的第一外接圆的直径为D1,延伸部所在的第二外接圆的直径为D0,0.5mm≤D0-D1≤4mm,叶片主体的拱弧线与第一外接圆交接、其交接处形成叶片出口点,拱弧线的切线和第一外接圆的切线在叶片出口点的位置形成叶片出口角α,165°≤α≤180°。本发明的离心风叶采用叶片出口外延边方式,在保证叶片加工质量的前提下,可以增加叶片出口角α的大小,使其增大至170～180°,可降低叶片生产故障,提高风叶性能,获得超出传统风叶叶片出口角的叶片。(The utility model provides a centrifugal fan blade of improvement, including chassis and a plurality of blades of annular distribution on the chassis, the blade includes blade main part and the extension of outwards extending in blade main part one end, the diameter of the first circumscribed circle at blade main part place is D1, the diameter of the second circumscribed circle at extension place is D0, 0.5mm is less than or equal to D0-D1 and is less than or equal to 4mm, the camber line and the first circumscribed circle handing-over of blade main part, its handing-over department forms the blade exit point, the tangent line of camber line and the tangent line of first circumscribed circle form blade exit angle alpha in the position of blade exit point, 165 is less than or equal to alpha and is less than or equal to 180. According to the centrifugal fan blade, a mode that the blade outlet extends outwards is adopted, the size of the blade outlet angle alpha can be increased to 170-180 degrees on the premise of ensuring the processing quality of the blade, the production faults of the blade can be reduced, the performance of the fan blade is improved, and the blade exceeding the blade outlet angle of the traditional fan blade is obtained.)

1. The utility model provides a centrifugal fan blade of improvement, includes chassis (1) and a plurality of blades (2) of annular distribution on chassis (1), its characterized in that: the blade (2) comprises a blade main body (2.1) and an extension part (2.2) extending outwards from one end of the blade main body (2.1), the diameter of a first circumscribed circle (c) where the blade main body (2.1) is located is D1, the diameter of a second circumscribed circle (D) where the extension part (2.2) is located is D0, 0.5mm is larger than or equal to D0-D1 and is smaller than or equal to 4mm, a camber line (2.1.1) of the blade main body (2.1) is connected with the first circumscribed circle (c), a blade outlet point (b) is formed at the connection position, a blade outlet angle alpha is formed by a tangent line of the camber line (2.1.1) and a tangent line of the first circumscribed circle (c) at the position of the blade outlet point (b), and alpha is larger than or equal to 165 degrees and is smaller than or equal to 180 degrees.

2. The improved centrifugal fan blade of claim 1, wherein: the extension part (2.2) is connected with the second circumcircle (d), one end of the connection part of the extension part and the second circumcircle (d) forms a blade extension outlet point (a), and the blade extension outlet point (a) is connected with the blade outlet point (b) through an arc line (2.2.1) to form an edge line on one side of the extension part (2.2).

3. The improved centrifugal fan blade of claim 2, wherein: two side surfaces of the extension part (2.2) are smooth cambered surfaces.

4. The improved centrifugal fan blade of claim 2, wherein: the thickness of the extension part (2.2) is larger than that of the blade main body (2.1).

5. The improved centrifugal fan blade of claim 2, wherein: the fan blade is characterized by further comprising a positioning ring (3), wherein one end of the blade (2) is connected to the chassis (1), and the other end of the blade is connected to the positioning ring (3).

6. An improved centrifugal fan blade according to claim 5, wherein: the blade main body (2.1) is connected with the positioning ring (3) through the extension part (2.2), and the extension part (2.2) is located between the blade main body (2.1) and the positioning ring (3).

7. The improved centrifugal fan blade of claim 1, wherein: the number of the blades (2) is 30-70.

8. The improved centrifugal fan blade of claim 1, wherein: the center of the chassis (1) is provided with an installation sleeve (1.1) for installing a motor shaft.

9. An improved centrifugal fan blade according to any one of claims 1-8, wherein: the centrifugal fan blade is made of plastics.

Technical Field

The invention relates to the technical field of fans, in particular to an improved centrifugal fan blade.

Background

As shown in fig. 4-5, a conventional centrifugal fan blade includes a chassis 11 and a plurality of blades 12 annularly distributed on the chassis 11, where the blades 12 form an outlet angle β at an outlet point h, and in actual plastic impeller production and processing, the outlet angle β can only be controlled below 165 ° due to production process constraints, so that if the performance of the fan blade is to be improved, the rotation speed of the fan blade can only be improved, but increasing the rotation speed of the fan blade inevitably increases noise generated when the fan blade rotates, which affects user experience.

Therefore, further improvements are needed.

Disclosure of Invention

The invention aims to provide an improved centrifugal fan blade which is simple in structure, superior in performance, low in noise and high in practicability, so as to overcome the defects in the prior art.

The improved centrifugal fan blade designed according to the purpose comprises a chassis and a plurality of blades which are annularly distributed on the chassis, and is characterized in that: the blade comprises a blade body and an extension part extending outwards at one end of the blade body, the diameter of a first circumscribed circle where the blade body is located is D1, the diameter of a second circumscribed circle where the extension part is located is D0, 0.5mm is not less than D0-D1 is not more than 4mm, an arc line of the blade body is connected with the first circumscribed circle, a blade exit point is formed at the connection position of the arc line and the tangent line of the first circumscribed circle, a blade exit angle alpha is formed at the position of the blade exit point, and alpha is not less than 165 degrees and not more than 180 degrees.

And one end of the joint of the extension part and the second external circle forms a blade extension outlet point, and the blade extension outlet point is connected with the blade outlet point through an arc line to form an edge line on one side of the extension part.

Two side surfaces of the extension part are smooth cambered surfaces.

The extension portion has a thickness greater than a thickness of the blade body.

The device also comprises a positioning ring, wherein one end of the blade is connected to the chassis, and the other end of the blade is connected to the positioning ring.

The blade main body is connected with the positioning ring through the extension part, and the extension part is located between the blade main body and the positioning ring.

The number of the blades is 30-70.

And the center of the chassis is provided with an installation sleeve for installing a motor shaft.

The centrifugal fan blade is made of plastics.

According to the centrifugal fan blade, the extension part extends out of the outer end of the blade main body, so that the size of the outlet angle alpha of the blade can be increased to 170-180 degrees on the premise of ensuring the processing quality of the blade, and the centrifugal fan blade can still obtain better performance under the condition of smaller rotating speed of the fan blade, so that the rotating speed of the fan blade can be reduced, the noise of the fan blade is reduced, meanwhile, the structure can reduce the production faults of the blade, improve the performance of the fan blade, and obtain the blade exceeding the outlet angle of the blade of the traditional fan blade.

Drawings

Fig. 1 is a front view of a centrifugal blade according to an embodiment of the present invention.

Fig. 2 is an enlarged schematic view of a portion a in fig. 1.

Fig. 3 is a schematic view of an overall structure of a centrifugal fan blade according to an embodiment of the present invention.

Fig. 4 is a front view of a conventional centrifugal fan blade.

Fig. 5 is an enlarged schematic view of the structure at B in fig. 4.

Fig. 6 is a comparison graph of air volume-noise of the centrifugal fan blade according to an embodiment of the present invention.

Detailed Description

The invention is further described with reference to the following figures and examples.

Referring to fig. 1-3, the improved centrifugal fan blade includes a chassis 1 and a plurality of blades 2 annularly distributed on the chassis 1, each blade 2 includes a blade main body 2.1 and an extension portion 2.2 extending outward from one end of the blade main body 2.1, a first circumcircle c on which the blade main body 2.1 is located has a diameter D1, a second circumcircle D on which the extension portion 2.2 is located has a diameter D0, 0.5mm or more and D0-D1 or less and 4mm or less, a blade exit point b is formed at a junction of the camber line 2.1.1 of the blade main body 2.1 and the first circumcircle c, and a blade exit point b is formed at a position of the blade exit point b by a tangent line of the camber line 2.1.1 and a tangent line of the first circumcircle cThe opening angle alpha is larger than or equal to 165 degrees and smaller than or equal to 180 degrees, and the blade outlet angle alpha of the embodiment is 170-180 degrees. Formula of relation between fan total pressure and blade outlet angleTherefore, the total pressure of the fan is related to the size of the blade outlet angle, and the total pressure of the fan is increased along with the increase of the blade outlet angle, so that the same total pressure of the fan can be obtained by adopting an impeller with a larger blade outlet angle and adopting a smaller fan rotating speed, the noise reduction design of the fan is facilitated, and the pneumatic performance of the fan can be controlled more effectively.

Referring to fig. 6, fig. 6 is a comparison graph of air volume-noise of a centrifugal fan blade, a certain fan blade L200-70 is tested, the upper curve of fig. 6 is the test result of air volume-noise of a traditional fan blade, and the lower curve is the test result of air volume-noise of the fan blade of the present invention, and it can be seen from the graph that under the condition of the same air volume, the noise of the fan blade of the present invention is reduced by 0.5db compared with the noise of the traditional fan blade.

One end of the joint of the extension part 2.2 and the second circumscribed circle d forms a blade extending point a, the blade extending point a is connected with the blade outlet point b through an arc line 2.2.1 to form an edge line on one side of the extension part 2.2, and two side surfaces of the extension part 2.2 are smooth arc surfaces. The design is beneficial to processing the blade 2, reduces the production faults of the blade 2 and can increase the size of the blade outlet angle alpha.

The thickness of the extension 2.2 is greater than the thickness of the blade body 2.1.

Still include holding ring 3, the one end of blade 2 is connected on chassis 1, the other end is connected on holding ring 3, and holding ring 3 can fix a position each blade 2, effectively improves the bulk strength of fan blade.

The blade body 2.1 is connected to the positioning ring 3 by an extension 2.2, the extension 2.2 being located between the blade body 2.1 and the positioning ring 3.

The number of blades 2 is 41.

The center of chassis 1 is equipped with the installation cover 1.1, and installation cover 1.1 is used for installing the motor shaft of fan blade.

The centrifugal fan blade is made of plastic.

The foregoing is a preferred embodiment of the present invention, and the basic principles, principal features and advantages of the invention are shown and described. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are intended to illustrate the principles of the invention, but that various changes and modifications may be made without departing from the spirit and scope of the invention, and the invention is intended to be protected by the following claims. The scope of the invention is defined by the appended claims and equivalents thereof.