Fan for ventilation of automobile seat

Abstract

The invention belongs to the technical field of fan noise reduction, and discloses a fan for ventilation of an automobile seat, which comprises a motor, the motor drives an impeller to rotate, the fan also comprises an odd number of blades which are non-uniformly distributed around the center of the impeller at intervals, and the sizes of the blades are consistent. Compared with a traditional fan, the noise value of the fan can be effectively reduced by adopting unequal-pitch non-uniform distribution, the noise peak value corresponding to the passing frequency of the original blade is scattered and distributed, no particularly remarkable peak value exists, and therefore the decibel value of the highest frequency point is reduced by more than 10 dB.

Description

Technical Field

[0001] This invention belongs to the field of fan noise reduction technology, specifically a fan for car seat ventilation. Background Technology

[0002] Small axial fans are convenient to use and inexpensive, and are widely used for heat dissipation and ventilation in both civilian and commercial applications. In recent years, due to the rapid development of the computer industry and the improvement of people's living standards, high-performance, low-noise small axial fans have become the preferred choice for heat dissipation. Fan noise can be divided into discrete and broadband noise from the perspective of noise frequency. Noise control is generally considered from three aspects: first, reducing the noise source; second, reducing noise by using silencers or sound insulators along the noise propagation path; and third, protecting the noise receiver. The aerodynamic noise generated by fan blades is much greater than the mechanical and electromagnetic noise of the fan. If the fan inlet and outlet and blade structure can be improved, the noise radiated by the fan can be significantly reduced. Noise reduction through blade design has great research and application prospects. Therefore, some blade treatment methods have emerged, such as: perforating blades to reduce fan eddy current noise, using forward-swept blades to reduce noise, cutting the suction surface of flat blades to reduce noise, and using soft-edge blades to reduce noise in low-flow areas. Among these, using non-uniformly distributed blades with unequal spacing is also a noise reduction measure. Traditional small axial fans use uniformly distributed blades, which results in relatively large discrete noise peaks. By changing the blade distribution to a non-uniform distribution with unequal pitch, the fan noise level can be effectively reduced.

[0003] A fan for ventilating car seats is proposed to solve the above problems. Summary of the Invention

[0004] To address the problems mentioned in the background section, the present invention provides a fan for ventilating car seats, which solves the problems in the prior art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a fan for ventilating car seats, including a motor that drives an impeller to rotate, and an odd number of blades with a non-uniformly distributed spacing around the center of the impeller, the blades being of the same size.

[0006] Preferably, there are 17 blades, and the blades are arranged at specific angles clockwise and counterclockwise around the center of the impeller, with an interval of 25.13° as the starting and ending point.

[0007] Preferably, the diameter of the impeller is 80-100 mm; the diameter of the blades surrounding the center of the impeller is 76-96 mm.

[0008] Preferably, the arc length of the blade is 32-36 mm.

[0009] Preferably, the interval angle from the starting point to the ending point is modulated by cosine frequency, and the cosine frequency modulation formula is as follows: Φi′=Φi+Φi*β*cos(mx), where Φi is the original spacing angle of the uniformly spaced blades (number of blades / 360°), Φi′ is the new spacing angle of the i-th blade after the non-uniform spacing arrangement is modified, β is the maximum percentage of the spacing angle change, n is the number of repetitions of the blade spacing angle to be used, and 0≦x≦2π.

[0010] Preferably, the spacing angle of the blades around the center of the impeller is: 25.13°, 23.06°, 20.02°, 17.58°, 17.01°, 18.62°, 21.57°, 18.62°, 21.57°, 24.31°, 25.41°, 24.30°, 21.57°, 18.62°, 21.57°, 18.62°, 17.01°, 17.58°, 20.02°, 23.06°, 25.13°.

[0011] Preferably, it also includes a fan top cover and a fan bottom shell, wherein the fan top cover, impeller, motor, PCB board and fan bottom shell are arranged in sequence to form a fan.

[0012] Preferably, the motor includes a magnetic frame, a stator, a shaft, a bearing, and enameled wire, which are fixed inside the fan by a snap ring; the shaft passes through the PCB board and is connected to the bearing, and the motor is electrically connected to the PCB board through the enameled wire; a power interface is provided on the bottom of the fan, and an external power source provides power to the PCB board and the motor; a label is provided on the bottom of the fan bottom, and the label is pasted on the bottom of the fan bottom.

[0013] Preferably, the impeller has a diameter of 96 mm; the blades have a diameter of 92 mm around the center of the impeller.

[0014] Preferably, the arc length of the blade is 35.37 mm.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0016] This invention utilizes an odd number of blades with a non-uniformly distributed spacing around the center of the impeller. The spacing between each blade is dispersed, and this non-uniform blade distribution modulates the frequency. The noise peaks corresponding to the frequencies passed by the originally uniformly spaced blades are dispersed, eliminating particularly significant peaks, and reducing the noise at frequencies passed by the non-uniformly spaced blades by more than 10 dB. As a result, the audible whistling sound is significantly reduced; when installed in a car seat, the whistling sound is completely inaudible, with only the sound of wind present, effectively improving the auditory experience. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the fan structure of the present invention;

[0018] Figure 2 This is a schematic diagram of the non-uniform spacing of the blades in this invention;

[0019] Figure 3 This is a schematic diagram of the blade spacing angle of the present invention;

[0020] Figure 4 This is a schematic diagram showing the size of the impeller of the present invention;

[0021] Figure 5 This is a FFT spectrum of a conventionally evenly spaced impeller during rotation.

[0022] Figure 6 This is the rotating FFT spectrum of the non-uniformly spaced impeller of the present invention.

[0023] In the diagram: 1. Fan top cover; 2. Impeller; 3. Magnetic frame; 4. Shaft core; 5. Enamelled wire; 6. Stator; 7. PCB board; 8. Bearing; 9. Fan bottom shell; 10. Spring; 11. Snap ring; 12. Label; 201. Blade. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Figures 1-4 As shown in Embodiment 1, the present invention provides a fan for car seat ventilation, including a motor that drives an impeller to rotate, and an odd number of blades with non-uniformly distributed spacing around the center of the impeller, as shown in the figure. The spacing angle of each blade is different, that is, the spacing angle A≠B≠C≠D....; the blades are of the same size; there are 17 blades, and the blades are set at specific angles clockwise and counterclockwise around the starting point of the spacing angle around the center of the impeller, with an interval of 25.13° as the starting and ending point.

[0025] The impeller has a diameter of 80-100 mm; the blades have a diameter of 76-96 mm around the center of the impeller. Preferably, the impeller has a diameter of 96 mm; the blades have a diameter of 92 mm around the center of the impeller.

[0026] The blade has an arc length of 32-36 mm; preferably, the blade has an arc length of 35.37 mm. The blade has an inner diameter of 52.1 mm.

[0027] The spacing angle of the blades around the impeller center, from the starting point to the ending point, is modulated using a cosine frequency. The cosine frequency modulation formula is as follows: Φi′=Φi+Φi*β*cos(mx), where Φi is the original spacing angle of uniformly spaced blades (number of blades / 360°), Φi′ is the new spacing angle of the i-th blade after modification of the non-uniform spacing arrangement, β is the maximum percentage change in the spacing angle, and n is the number of repetitions of the blade spacing angle to be used, generally between n=2 and n=11, 0≦x≦2π. Through extensive testing, the variable β, which is related to the maximum percentage change in the spacing angle, generally remains in the range of approximately 0.005 to approximately 0.05, with n=9 being optimal.

[0028] The angles of the blade spacing around the center of the impeller are: 25.13°, 23.06°, 20.02°, 17.58°, 17.01°, 18.62°, 21.57°, 18.62°, 21.57°, 24.31°, 25.41°, 24.30°, 21.57°, 18.62°, 21.57°, 18.62°, 17.01°, 17.58°, 20.02°, 23.06°, and 25.13°.

[0029] A fan for ventilating car seats includes a motor that drives an impeller to rotate, and an odd number of blades of uniform size spaced at a non-uniformly distributed interval around the center of the impeller. It also includes a fan top cover and a fan bottom cover, which are arranged sequentially to form the fan. The motor includes a magnetic frame, a stator, a shaft, a bearing, and enameled wire, and is fixed inside the fan by a retaining ring. The shaft passes through the PCB board and connects to the bearing. The motor is electrically connected to the PCB board via the enameled wire. A power interface is provided on the fan bottom cover, providing power to the PCB board and the motor from an external power source. A label is affixed to the bottom of the fan bottom cover.

[0030] like Figure 5 As shown, the current fan has 17 blades. At a speed of 4800 rpm, the fan can meet the performance requirements of car seat ventilation and overall seat noise.

[0031] The formula for calculating impeller speed is: N = 60 x F / P, where N represents the impeller speed in RPM; F represents the impeller's rotational frequency in Hz; and P represents the number of impeller blades.

[0032] Based on the above formula, when the rotation speed is about 4800 rpm, the impeller rotation frequency is about 1360 Hz. The human ear is most sensitive to sounds in the range of about 1000 Hz to 4000 Hz.

[0033] like Figure 5As shown, there will be a significant noise peak around 1360Hz. At this point, the human ear can clearly hear a high-frequency whistling sound, which is an octave of the number of blades.

[0034] like Figure 2 As shown, the blades of the impeller are made into unequally spaced blades by adjusting the angle of each blade. The blade angles start from angle A and are 24.31°, 21.57°, 18.62°, 17.01°, 17.58°, 20.02°, 23.06°, 25.13°, 25.13°, 23.06°, 20.02°, 17.58°, 17.01°, 18.62°, 21.57°, 24.31° and 25.41°.

[0035] like Figure 6 As shown, the blades form an uneven spacing around the central hub or shaft of the impeller. The normal heat dissipation or other functions of the fan are not affected. The blade number ratio frequency fluctuates over time, but the high-frequency whistling sound emitted by the fan is reduced.

[0036] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0037] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A fan for ventilating car seats, comprising a motor that drives an impeller to rotate, characterized in that: It also includes an odd number of blades with a non-uniformly distributed spacing around the center of the impeller, and the blades are of the same size.

2. The fan according to claim 1, characterized in that: The blades consist of 17 blades, and the blades are arranged at specific angles clockwise and counterclockwise around the center of the impeller, with an interval of 25.13° as the starting and ending point.

3. The fan according to claim 1, characterized in that: The diameter of the impeller is 80-100mm; the diameter of the blades surrounding the center of the impeller is 76-96mm.

4. The fan according to claim 1, characterized in that: The arc length of the blade is 32-36 mm.

5. The fan according to any one of claims 2 to 4, characterized in that: The interval angle from the starting point to the ending point is modulated by cosine frequency. The cosine frequency modulation formula is as follows: Φi′=Φi+Φi*β*cos(mx), where Φi is the original spacing angle of the uniformly spaced blades (number of blades / 360°), Φi′ is the new spacing angle of the i-th blade after the non-uniform spacing arrangement is modified, β is the maximum percentage of the spacing angle change, n is the number of repetitions of the blade spacing angle to be used, and 0≦x≦2π.

6. The fan according to claim 5, characterized in that: The spacing angles of the blades around the center of the impeller are: 25.13°, 23.06°, 20.02°, 17.58°, 17.01°, 18.62°, 21.57°, 18.62°, 21.57°, 24.31°, 25.41°, 24.30°, 21.57°, 18.62°, 21.57°, 18.62°, 17.01°, 17.58°, 20.02°, 23.06°, and 25.13°.

7. The fan according to claim 1, characterized in that: It also includes a fan top cover and a fan bottom shell, wherein the fan top cover, impeller, motor, PCB board and fan bottom shell are arranged in sequence to form a fan.

8. The fan according to claim 7, characterized in that: The motor includes a magnetic frame, stator, shaft, bearing, and enameled wire, which are fixed inside the fan by a snap ring. The shaft passes through the PCB board and is connected to the bearing. The motor is electrically connected to the PCB board through the enameled wire. A power interface is provided on the bottom of the fan, and an external power source provides power to the PCB board and the motor. A label is provided on the bottom of the fan bottom, and the label is affixed to the bottom of the fan bottom.

9. The fan according to claim 3, characterized in that: The impeller has a diameter of 96 mm; the blades have a diameter of 92 mm around the center of the impeller.

10. The fan according to claim 4, characterized in that: The blade has an arc length of 35.37 mm.

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