Low-noise cooling fan and automobile

Abstract

The invention discloses a low-noise cooling fan and an automobile, and relates to the technical field of cooling fans, and the low-noise cooling fan comprises a center hub used for being connected with a motor shaft; the blades are annularly and unevenly distributed around the central hub, and the distribution angles between the blades are different; the blade roots of the plurality of blades are respectively connected with the central hub; the flow guide ring is connected with the blade tops of the multiple blades; the turbulent flow assemblies are arranged on the suction surfaces of the blades, the turbulent flow assemblies can extend out step by step according to the rotating speed of the fan, when airflow passes through the turbulent flow assemblies, high-strength induced vortexes can be generated, high-energy fluid outside a boundary layer and fluid in the boundary layer are mixed, flow separation of the boundary layer of the suction surfaces is delayed, and the flow separation efficiency is improved. Local reflux and boundary layer thickening of the blade surface are controlled, the airfoil lift force is improved, and meanwhile generation of fan noise is restrained.

Description

Technical Field

[0001] The present application belongs to the technical field of cooling fans, and in particular relates to a low-noise cooling fan and a car. Background Art

[0002] Axial fans are a core equipment widely used in industrial production and life. During their design and manufacturing process, a series of key technical problems need to be overcome to ensure their excellent performance, high efficiency and long-term reliability. This includes optimizing the fan blade shape to improve air flow efficiency, balancing the speed and power output to achieve the best energy efficiency ratio; at the same time, controlling the noise level to reduce interference to the environment and operators. Affected by the growing heat dissipation requirements of electric vehicles and fuel cell vehicles, the performance of traditional automotive front-end cooling modules is gradually insufficient, especially in light trucks and heavy trucks. Insufficient heat dissipation will affect the performance of air conditioning on the one hand, and the driving safety of the car on the other hand. At the same time, with people's growing requirements for car comfort and noise control, it is crucial to provide a quiet environment during vehicle driving to ensure the user's riding experience. In response to the needs of high heat dissipation, high energy consumption and low noise, it is urgent to develop a high-performance, high-efficiency and low-noise axial fan. Summary of the invention

[0003] The present application provides a low-noise cooling fan and a car, aiming to at least to some extent solve the technical problems of poor cooling effect and high noise of axial flow fans in the prior art.

[0004] In order to solve the above technical problems, this application adopts the following technical solutions:

[0005] The first aspect of an embodiment of the present application provides a low-noise cooling fan, comprising: a central hub for connecting to a motor shaft; a plurality of blades, which are unevenly distributed in a ring around the central hub, and the distribution angles of the blades are different; the roots of the plurality of blades are respectively connected to the central hub; a guide ring, which is connected to the blade tops of the plurality of blades; a spoiler assembly, which is arranged on the suction surface of each blade, and the spoiler assembly can be gradually extended according to the rotation speed of the fan. When the airflow passes through the spoiler assembly, a high-intensity induced vortex can be generated, which mixes the high-energy fluid outside the boundary layer with the fluid inside the boundary layer, delays the separation of the suction surface boundary layer flow, controls the local backflow and boundary layer thickening on the blade surface, enhances the airfoil lift, and suppresses the generation of fan noise.

[0006] In some embodiments, the spoiler assembly includes: a first spoiler unit, which is arranged in a first mounting hole on a side of the blade close to the blade root; and at least two second spoiler units, which are arranged in second mounting holes at the blade edge of the blade.

[0007] In some embodiments, the first spoiler unit includes: a first lifting block, including a first telescopic portion and a first abutment portion, the first telescopic portion is arranged in the first mounting hole, and the first abutment portion is connected to the lower end of the first telescopic portion; a first fixed shaft, arranged inside the blade, one end of the first fixed shaft is connected to the blade root of the blade; a first driving spring, one end of which is connected to the other end of the first fixed shaft; a first transmission rod, one end of which is connected to the first driving spring, and the other end of the first transmission rod is connected to the first lifting block; when the blade rotates, the first driving spring extends under the action of centrifugal force to push the lifting block out through the first transmission rod.

[0008] In some embodiments, the second spoiler unit includes: a second lifting block, including a second telescopic portion and a second abutment portion, the second telescopic portion is arranged in the first mounting hole, and the second abutment portion is connected to the lower end of the second telescopic portion; a second fixed shaft, arranged inside the blade, one end of the second fixed shaft is connected to the blade root of the blade; a second driving spring, one end of which is connected to the other end of the second fixed shaft; a second transmission rod, one end of which is connected to the second driving spring, and the other end of the second transmission rod is connected to the second lifting block; when the blade rotates, the second driving spring extends under the action of centrifugal force to push the lifting block out through the second transmission rod.

[0009] In some embodiments, adjacent second lifting blocks are arranged at an angle along the rotation direction of the blade.

[0010] In some embodiments, three second spoiler units are provided, the angle between the second lifting block close to the guide ring and the inner wall of the guide ring is 0°, the angle between the outermost second lifting block and the second lifting block in the middle is 12°, and the angle between the outermost second lifting block and the innermost second lifting block is 24°.

[0011] In some embodiments, the first telescopic portion has a length of 18 mm to 23 mm, a width of 0.3 mm to 0.8 mm, and a height of 0.4 mm to 0.7 mm.

[0012] In some embodiments, the second telescopic portion has a length of 50 mm to 70 mm, a width of 0.3 mm to 0.8 mm, and a height of 0.4 mm to 0.7 mm.

[0013] In some embodiments, there are nine blades, and the distribution angles between the blades are 41.8°, 40.4°, 37.3°, 36.4°, 40.4°, 43.4°, 42.8°, and 40°, respectively.

[0014] A second aspect of an embodiment of the present application provides a car, in which the cooling fan is provided.

[0015] It can be seen from the above technical solution that the present application has at least the following advantages and positive effects:

[0016] A low-noise cooling fan in the present application can effectively suppress the generation of BPF (Blade Passing Frequency) of the fan by setting blades with uneven distribution. By setting the spoiler component, it can be gradually extended according to the rotation speed of the fan. The ejection height of the vortex generator is different at different rotation speeds, and the induced vortex strength generated is different to adapt to different working conditions. When the airflow passes through the spoiler component, a high-intensity induced vortex can be generated to mix the high-energy fluid outside the boundary layer with the fluid inside the boundary layer, delay the flow separation of the suction surface boundary layer, control the local backflow and boundary layer thickening on the surface of the blade, enhance the airfoil lift, and suppress the generation of fan noise. When the fan stops completely, the spoiler component returns to its original position. After CFD simulation analysis, compared with conventional fans, the present invention has an increase of 6-10% in air volume under the same back pressure, and an increase of 5%-8% in static pressure efficiency compared with the same conventional fan blades; the noise is reduced by 2-3dB; it can meet the requirements of high back pressure, large air volume and high heat dissipation of the fan.

[0017] A car in the present application can effectively suppress the generation of BPF of the fan by providing a low-noise cooling fan and non-uniformly distributed blades. By providing a spoiler component, the spoiler component can be gradually extended according to the rotation speed of the fan. The pop-up height of the vortex generator is different at different rotation speeds, and the induced vortex strength generated is different to adapt to different working conditions. When the airflow passes through the spoiler component, a high-intensity induced vortex can be generated to mix the high-energy fluid outside the boundary layer with the fluid inside the boundary layer, delay the flow separation of the suction surface boundary layer, control the local backflow and boundary layer thickening on the surface of the blade, enhance the airfoil lift, and suppress the generation of fan noise at the same time. It can meet the requirements of high back pressure, large air volume, and high heat dissipation of automobile fans, can effectively reduce the noise of automobile cooling fans, improve the heat dissipation performance of air conditioners, provide a quiet environment during vehicle driving, and enhance the user's vehicle comfort and riding experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0019] Figure 1 is a structural schematic diagram of a vehicle body assembly in an embodiment of the present application;

[0020] Figure 2is a front view of a low-noise cooling fan in an embodiment of the present application;

[0021] Figure 3 is a structural schematic diagram of a first spoiler unit of a low-noise cooling fan in an embodiment of the present application;

[0022] Figure 4 is a structural schematic diagram of a second spoiler unit of a low-noise cooling fan in an embodiment of the present application;

[0023] The reference numerals are as follows: 100, center hub; 200, blades; 300, guide ring; 400, spoiler assembly; 410, first spoiler unit; 411, first lifting block; 412, first fixed shaft; 413, first drive spring; 414, first transmission rod; 415, first limiting ring; 420, second spoiler unit; 421, second lifting block; 422, second fixed shaft; 423, second drive spring; 424, second transmission rod; 425, second limiting ring. DETAILED DESCRIPTION

[0024] In order to make the technical personnel in the technical field to which the present application belongs to understand the present application more clearly, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0025] Figure 1 is a schematic diagram of the structure of a low-noise cooling fan in an embodiment of the present application; Figure 1As shown, the fan includes: a central hub 100 for connecting to a motor shaft; a plurality of blades 200, which are unevenly distributed in a ring around the central hub 100, and the distribution angles of the blades 200 are all different; the roots of the plurality of blades 200 are respectively connected to the central hub 100; a guide ring 300, which is connected to the blade tops of the plurality of blades 200; a spoiler assembly 400, which is arranged on the suction surface of each blade 200, and the spoiler assembly 400 can be gradually extended according to the rotation speed of the fan. When the airflow passes through the spoiler assembly 400, a high-intensity induced vortex can be generated to mix the high-energy fluid outside the boundary layer with the fluid inside the boundary layer, delay the separation of the suction surface boundary layer flow, control the local backflow and boundary layer thickening on the surface of the blade 200, enhance the airfoil lift, and suppress the generation of fan noise. By setting the blades 200 with non-uniform distribution, the BPF generation of the fan can be effectively suppressed. By setting the spoiler assembly 400, it can be gradually extended according to the rotation speed of the fan. The ejection height of the vortex generator is different at different rotation speeds, and the induced vortex strength generated is different to adapt to different working conditions. When the airflow passes through the spoiler assembly 400, a high-intensity induced vortex can be generated to mix the high-energy fluid outside the boundary layer with the fluid inside the boundary layer, delay the flow separation of the suction surface boundary layer, control the local backflow and boundary layer thickening on the surface of the blade 200, enhance the airfoil lift, and suppress the generation of fan noise. When the fan stops completely, the spoiler assembly 400 returns to its original position. After CFD simulation analysis, compared with conventional fans, the present invention has an increase of 6-10% in air volume under the same back pressure, and an increase of 5%-8% in static pressure efficiency compared with the same conventional fan blades; the noise is reduced by 2-3dB; it can meet the requirements of high back pressure, large air volume, and high heat dissipation of the fan.

[0026] In some embodiments, a plurality of threaded holes are provided on the center hub 100, and the center hub 100 is connected to the motor shaft via a flange. When the motor is energized, the blades 200 are driven to rotate. Flanges of different sizes are installed on the threaded holes of the center hub 100 to accommodate motors of different specifications, thereby improving the adaptability of the fan.

[0027] In some embodiments, by providing the guide ring 300, the wind flow is ensured to be more uniform and wider, avoiding the discomfort caused by traditional fans. The airflow will generate negative pressure through the guide ring 300 and the internal structure of the fan, thereby attracting more air and forming a flowing turbine effect, making the air volume more continuous and stable; the guide ring 300 can also increase the air volume and reduce noise, and improve the heat dissipation efficiency by dividing the wind flow, thereby enhancing the performance of the fan. These designs not only improve the user experience of the fan, but also extend the life of the fan.

[0028] See also Figure 2 , Figure 2 It is a front view of a low-noise cooling fan in an embodiment of the present application.

[0029] In some embodiments, the spoiler assembly 400 includes: a first spoiler unit 410, which is arranged in a first mounting hole on the side of the blade 200 close to the root; at least two second spoiler units 420, which are arranged in a second mounting hole at the blade edge of the blade 200. The length of the second spoiler unit 420 is greater than the length of the first spoiler unit 410. Since the wind speed on the side close to the central hub 100 is relatively small, a shorter first spoiler unit 410 can achieve the corresponding technical effect. The wind speed on the side close to the guide ring 300 is relatively large, and multiple second spoiler units 420 are arranged. When the airflow passes through, a high-intensity induced vortex can be generated, and the high-energy fluid outside the boundary layer is mixed with the fluid inside the boundary layer, delaying the separation of the boundary layer flow on the airfoil, controlling the local backflow and boundary layer thickening on the surface of the blade, effectively improving the lift of the airfoil, and suppressing the generation of fan noise. Specifically, the length of the first telescopic portion is 20 mm, the width is 0.5 mm, and the height is 0.6 mm. The second telescopic portion has a length of 60 mm, a width of 0.5 mm, and a height of 0.6 mm.

[0030] See also Figure 3 , Figure 3 4 is a schematic structural diagram of a first spoiler unit 410 of a low-noise cooling fan in an embodiment of the present application;

[0031] In some embodiments, the first spoiler unit 410 includes: a first lifting block 411, including a first telescopic portion and a first abutting portion, the first telescopic portion is arranged in the first mounting hole, and the first abutting portion is connected to the lower end of the first telescopic portion; a first fixed shaft 412, arranged inside the blade 200, one end of the first fixed shaft 412 is connected to the blade root of the blade 200; a first driving spring 413, one end of which is connected to the other end of the first fixed shaft 412; a first transmission rod 414, one end of which is connected to the first driving spring 413, and the other end of the first transmission rod 414 is connected to the first lifting block 411; when the blade 200 rotates, the first driving spring 413 is extended under the action of centrifugal force to push the lifting block out through the first transmission rod 414. Specifically, the first transmission rod 414 is in an arc shape, and the lateral force generated by the spring is converted into a vertical force and transmitted to the first lifting block 411 through the first transmission tube. When the first abutting portion abuts against the inner wall of the blade 200, the first telescopic portion is completely ejected. In this embodiment, the first driving spring 413 is stretched and ejected by the centrifugal force, and no other power system is required, so the manufacturing cost is low.

[0032] In some embodiments, the first spoiler unit 410 also includes a first limiting ring 415, which is connected to the upper wall of the blade 200 through a connecting rod. The first limiting ring 415 is also connected to the first transmission rod 414 through a connecting rod. The transmission direction of the first transmission rod 414 is limited by the first limiting ring 415 to ensure the correctness of force transmission.

[0033] See also Figure 4 , Figure 4 4 is a schematic structural diagram of a second spoiler unit 420 of a low-noise cooling fan in an embodiment of the present application;

[0034] In some embodiments, the second spoiler unit 420 includes: a second lifting block 421, including a second telescopic portion and a second abutting portion, the second telescopic portion is arranged in the first mounting hole, and the second abutting portion is connected to the lower end of the second telescopic portion; a second fixed shaft 422, arranged inside the blade 200, one end of the second fixed shaft 422 is connected to the blade root of the blade 200; a second driving spring 423, one end of which is connected to the other end of the second fixed shaft 422; a second transmission rod 424, one end of which is connected to the second driving spring 423, and the other end of the second transmission rod 424 is connected to the second lifting block 421; when the blade 200 rotates, the second driving spring 423 is extended under the action of centrifugal force to push the lifting block out through the second transmission rod 424. Specifically, the second transmission rod 424 is in an arc shape, and the lateral force generated by the spring is converted into a vertical force and transmitted to the second lifting block 421 through the second transmission tube. When the second abutting portion abuts against the inner wall of the blade 200, the second telescopic portion is completely ejected. In this embodiment, the second driving spring 423 is stretched and ejected by the second lifting block 421 under the action of centrifugal force, and no other power system is required, so the manufacturing cost is low.

[0035] In some embodiments, the second spoiler unit 420 also includes a second limiting ring 425, which is connected to the upper wall of the blade 200 through a connecting rod. The second limiting ring 425 is also connected to the second transmission rod 424 through a connecting rod. The transmission direction of the second transmission rod 424 is limited by the second limiting ring 425 to ensure the correctness of force transmission.

[0036] See also Figure 2 .

[0037] In some embodiments, each adjacent second lifting block 421 is arranged at an angle along the rotation direction of the blade 200, so as to achieve a better turbulence effect.

[0038] In some embodiments, three second spoiler units 420 are provided, and the angle between the second lifting block 421 close to the side of the guide ring 300 and the inner wall of the guide ring 300 is 0°, the angle between the outermost second lifting block 421 and the second lifting block in the middle is 12°, and the angle between the outermost second lifting block 421 and the innermost second lifting block 421 is 24°. Specifically, the inclination directions of the second lifting blocks 421 are the same; in other embodiments, four, five or more second spoiler units 420 can be set, and the clamps between each second lifting block 421 can be set to 10°~15° to achieve better spoiler effect.

[0039] In some embodiments, the length of the first telescopic portion is 18 mm to 23 mm, the width is 0.3 mm to 0.8 mm, and the height is 0.4 mm to 0.7 mm. The length of the second telescopic portion is 50 mm to 70 mm, the width is 0.3 mm to 0.8 mm, and the height is 0.4 mm to 0.7 mm.

[0040] In some embodiments, there are nine blades 200, and the distribution angles between the blades 200 are 41.8°, 40.4°, 37.3°, 36.4°, 40.4°, 43.4°, 42.8°, and 40°, respectively. When the fan blades 200 rotate, they form periodic pressure waves in the air. These pressure waves propagate at a certain frequency, forming a specific noise spectrum. This frequency is directly related to the rate at which the blades 200 pass through the air, so it is called the blade passing frequency (BPF). In addition, the uniformity of the incoming flow, the design of the blades 200, and the structure of the fan will affect the generation and intensity of the BPF noise; and setting blades 200 with different distribution angles can optimize the flow field and structure of the fan, which can effectively reduce the BPF noise.

[0041] In some embodiments, the blade 200 adopts a forward-bending structure. Through an appropriate forward bending angle, the forward-bending blade 200 can reduce the outer diameter of the impeller when the rotation speed, flow rate and energy head generated are the same, thereby reducing the size of the fan, reducing the volume and weight. This not only improves the strength of the blade 200, but also optimizes the flow field and reduces noise.

[0042] In other embodiments, a non-retractable spoiler block may be fixed on the blade 200. When the fan rotates, a high-intensity induced vortex can be generated when the airflow passes through. However, this embodiment cannot achieve different pop-up heights of the spoiler block at different speeds and cannot adapt to different working conditions.

[0043] In some embodiments, see the table below, the low-noise cooling fan in the present application is subjected to performance tests with ordinary fans, and the results are shown in Tables 1, 2 and 3 below, wherein Table 1 is a performance comparison of two fans with a diameter of 550 mm at 2000 rpm, Table 2 is a performance comparison of two fans with a diameter of 550 mm at 2500 rpm; Table 3 is a performance comparison of two fans with a diameter of 550 mm at 3000 rpm. Table 1 Table 2 Table 3

[0044] It can be seen from the above table that compared with conventional fans, under the same back pressure, the air volume of the present invention is increased by 6-10%, and the static pressure efficiency is increased by 5%-8% compared with the same conventional fan blades; the noise is reduced by 2-3dB; and the requirements of high back pressure, large air volume and high heat dissipation of the fan can be met.

[0045] The second aspect of the embodiment of the present application provides a car, wherein the car is provided with the cooling fan. By providing a low-noise cooling fan and non-uniformly distributed blades, the BPF of the fan can be effectively suppressed, and the spoiler assembly can be gradually extended according to the rotation speed of the fan. The ejection height of the vortex generator is different at different rotation speeds, and the induced vortex strength generated is different to adapt to different working conditions. When the airflow passes through the spoiler assembly, a high-intensity induced vortex can be generated, and the high-energy fluid outside the boundary layer is mixed with the fluid inside the boundary layer, delaying the separation of the suction surface boundary layer flow, controlling the local backflow and boundary layer thickening of the blade surface, and improving the airfoil lift. At the same time, the generation of fan noise can be suppressed, which can meet the requirements of high back pressure, large air volume, and high heat dissipation of the automobile fan, effectively reduce the noise of the automobile cooling fan, improve the heat dissipation performance of the air conditioner, provide a quiet environment during the vehicle driving process, and improve the user's comfort and riding experience.

[0046] It can be seen from the above technical solution that the present application has at least the following advantages and positive effects:

[0047] A low-noise cooling fan in the present application can effectively suppress the generation of BPF (Blade Passing Frequency) of the fan by setting blades with uneven distribution. By setting the spoiler component, it can be gradually extended according to the rotation speed of the fan. The ejection height of the vortex generator is different at different rotation speeds, and the induced vortex strength generated is different to adapt to different working conditions. When the airflow passes through the spoiler component, a high-intensity induced vortex can be generated to mix the high-energy fluid outside the boundary layer with the fluid inside the boundary layer, delay the flow separation of the suction surface boundary layer, control the local backflow and boundary layer thickening on the surface of the blade, enhance the airfoil lift, and suppress the generation of fan noise. When the fan stops completely, the spoiler component returns to its original position. After CFD simulation analysis, compared with conventional fans, the present invention has an increase of 6-10% in air volume under the same back pressure, and an increase of 5%-8% in static pressure efficiency compared with the same conventional fan blades; the noise is reduced by 2-3dB; it can meet the requirements of high back pressure, large air volume and high heat dissipation of the fan.

[0048] A car in the present application can effectively suppress the generation of BPF of the fan by providing a low-noise cooling fan and non-uniformly distributed blades. By providing a spoiler component, the spoiler component can be gradually extended according to the rotation speed of the fan. The pop-up height of the vortex generator is different at different rotation speeds, and the induced vortex strength generated is different to adapt to different working conditions. When the airflow passes through the spoiler component, a high-intensity induced vortex can be generated to mix the high-energy fluid outside the boundary layer with the fluid inside the boundary layer, delay the flow separation of the suction surface boundary layer, control the local backflow and boundary layer thickening on the surface of the blade, enhance the airfoil lift, and suppress the generation of fan noise at the same time. It can meet the requirements of high back pressure, large air volume, and high heat dissipation of automobile fans, can effectively reduce the noise of automobile cooling fans, improve the heat dissipation performance of air conditioners, provide a quiet environment during vehicle driving, and enhance the user's vehicle comfort and riding experience.

[0049] In the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0050] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise" and "counterclockwise" indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0051] In this application, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0052] In addition, the descriptions of "first", "second", etc. in this application are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0053] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A low-noise cooling fan, characterized in that: include: a center hub for connecting to the motor shaft; A plurality of blades are unevenly distributed in a ring shape around the central hub, and the distribution angles of the blades are different; the roots of the plurality of blades are respectively connected to the central hub; A guide ring connected to the blade tips of the plurality of blades; A spoiler assembly is arranged on the suction surface of each of the blades. The spoiler assembly can be gradually extended according to the rotation speed of the fan. When the airflow passes through the spoiler assembly, a high-intensity induced vortex can be generated to mix the high-energy fluid outside the boundary layer with the fluid inside the boundary layer, delay the flow separation of the suction surface boundary layer, control the local backflow on the blade surface and the thickening of the boundary layer, enhance the airfoil lift, and suppress the generation of fan noise.

2. The low-noise cooling fan according to claim 1, characterized in that: The spoiler assembly comprises: A first spoiler unit is arranged in a first mounting hole on a side of the blade close to the blade root; At least two second spoiler units are arranged in the second mounting holes at the blade edges of the blades.

3. The low-noise cooling fan according to claim 2, characterized in that: The first spoiler unit comprises: A first lifting block comprises a first telescopic portion and a first abutting portion, wherein the first telescopic portion is disposed in the first mounting hole, and the first abutting portion is connected to a lower end of the first telescopic portion; A first fixed shaft is arranged inside the blade, and one end of the first fixed shaft is connected to the blade root of the blade; a first driving spring, one end of which is connected to the other end of the first fixed shaft; A first transmission rod, one end of which is connected to the first driving spring, and the other end of which is connected to the first lifting block; When the blades rotate, the first driving spring is extended under the action of centrifugal force to push the lifting block to extend through the first transmission rod.

4. The low-noise cooling fan according to claim 2, characterized in that: The second spoiler unit comprises: A second lifting block comprises a second telescopic portion and a second abutting portion, wherein the second telescopic portion is disposed in the first mounting hole, and the second abutting portion is connected to a lower end of the second telescopic portion; A second fixed shaft is arranged inside the blade, and one end of the second fixed shaft is connected to the blade root of the blade; a second driving spring, one end of which is connected to the other end of the second fixed shaft; A second transmission rod, one end of which is connected to the second driving spring, and the other end of which is connected to the second lifting block; When the blades rotate, the second driving spring is extended under the action of centrifugal force to push the lifting block to extend through the second transmission rod.

5. The low-noise cooling fan according to claim 4, characterized in that: Each adjacent second lifting block is arranged at an angle along the rotation direction of the blade.

6. The low-noise cooling fan according to claim 4, characterized in that: There are three second spoiler units, the angle between the second jacking block close to the guide ring and the inner wall of the guide ring is 0°, the angle between the outermost second jacking block and the second jacking block in the middle is 12°, and the angle between the outermost second jacking block and the innermost second jacking block is 24°.

7. The low-noise cooling fan according to claim 3, characterized in that: The first telescopic portion has a length of 18 mm to 23 mm, a width of 0.3 mm to 0.8 mm, and a height of 0.4 mm to 0.7 mm.

8. The low-noise cooling fan according to claim 4, characterized in that: The second telescopic portion has a length of 50 mm to 70 mm, a width of 0.3 mm to 0.8 mm, and a height of 0.4 mm to 0.7 mm.

9. The low-noise cooling fan according to any one of claims 1 to 8, characterized in that: There are nine blades, and the distribution angles between the blades are 41.8°, 40.4°, 37.3°, 36.4°, 40.4°, 43.4°, 42.8°, and 40° respectively.

10. An automobile, characterized in that: The automobile is provided with a cooling fan as claimed in any one of claims 1 to 9.

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