CN108506231A - Fan assembly - Google Patents

Abstract

The invention discloses a fan device, which comprises a casing, a fan blade and a sound-absorbing tank body. The casing has an air inlet, an air outlet, an accommodating space and a bypass opening which communicate with each other. The fan blade is arranged in the accommodating space. The sound-absorbing tank body is arranged at the bypass opening and is located outside the accommodation space. The sound-absorbing tank body has an airflow passage, and the airflow passage communicates with the accommodation space through the bypass opening. Wherein, the fan blade sucks air through the air inlet, and generates airflow in the accommodation space, so that the airflow passes through the bypass opening and enters the airflow channel.

Description

fan unit

technical field

The invention relates to a fan device, in particular to a fan device with a sound-absorbing tank body.

Background technique

With the advancement and development of technology, the performance of electronic devices (such as desktop computers, notebook computers or servers) has been significantly improved. However, with the development of high-efficiency electronic devices, a large amount of heat is accompanied by it, which makes the temperature inside the electronic device rise and affects the performance of the electronic device. Therefore, the current heat dissipation methods of electronic devices mostly rely on cooling fans. Heat dissipation.

However, the cooling fan of the electronic device will generate noise due to the blade passing frequency, which reduces user experience. Generally speaking, the solution to the noise generated by the fan is to modify the blade shape of the fan or the shape of the internal flow channel of the fan. troubled.

Contents of the invention

The present invention is to provide a fan device to solve the problem in the prior art that it is still difficult to solve the problem of fan noise by modifying the shape of the blades of the fan or the shape of the internal flow channel of the fan.

A fan device disclosed in an embodiment of the present invention includes a housing, a fan blade and a sound-absorbing tank. The housing has an air inlet, an air outlet, an accommodating space and a bypass opening which communicate with each other. The fan blade is arranged in the accommodating space. The sound-absorbing tank body is arranged at the bypass opening and is located outside the accommodation space. The sound-absorbing tank body has an airflow passage, and the airflow passage communicates with the accommodation space through the bypass opening. Wherein, the fan blade inhales air through the air inlet, and generates airflow in the accommodation space, so that the airflow passes through the bypass opening and enters the airflow channel.

According to the fan device disclosed in the above-mentioned embodiments, since the fan device has a sound-absorbing tank body, the sound-absorbing tank body can reduce the noise generated by the blade passing frequency of the fan blade, so the electronic device equipped with the fan can improve user experience .

The above description of the content of the present invention and the following description of the implementation are used to demonstrate and explain the spirit and principle of the present invention, and to provide further explanation of the protection scope of the patent application claims of the present invention.

Description of drawings

FIG. 1 is a perspective view of a fan device disclosed according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of FIG. 1 .

FIG. 3 is a schematic diagram of the sound-absorbing tank shown in FIG. 1 .

FIG. 4 is a cross-sectional view of a fan device disclosed according to a second embodiment of the present invention.

Among them, reference signs:

1 fan unit

10, 10' housing

11 air inlet

12 air outlet

13, 13’ storage space

14 Bypass port

15 top plate

16 Bottom plate

17 side wall

171 First Wall Section

172 Second Wall Section

1721 connection section

1722 Tongue section

20, 20' fan blade

40, 40' silencer tank

41, 41’ air flow channel

42 long side panels

421 extension

422 diversion section

43 short side panels

44 slot bottom plate

45 upper side panel

46 lower side panel

50 porous wood

51 Breathable pores

60 incident waves

70 reflected waves

P plane

R axis

D direction

L, L2 length

lambda wavelength

S connection

Detailed ways

Please refer to Figure 1 to Figure 2. FIG. 1 is a perspective view of a fan device disclosed according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view of FIG. 1 .

The fan device 1 of this embodiment is, for example, a centrifugal fan, and is used in electronic devices such as notebook computers. The fan device 1 includes a casing 10 , a fan blade 20 and a sound-absorbing tank 40 .

The casing 10 is made of hard material such as plastic, and has an air inlet 11 , an air outlet 12 , an accommodating space 13 and a bypass opening 14 interconnected with each other. In detail, the casing 10 includes a top plate 15 , a bottom plate 16 and a side wall 17 , the top plate 15 and the bottom plate 16 are connected to opposite sides of the side wall 17 . The air inlet 11 is located on the top plate 15 , and the top plate 15 , the bottom plate 16 and the side wall 17 together surround the accommodating space 13 and form the air outlet 12 . The bypass port 14 is located on the side wall 17 . The bypass opening 14 divides the side wall 17 into a first wall portion 171 and a second wall portion 172 , and the second wall portion 172 has a connecting section 1721 and a tongue section 1722 connected thereto. The connection section 1721 is connected to the bypass opening 14 , and the tongue section 1722 is located at an end of the connection section 1721 away from the bypass opening 14 .

The fan blade 20 is disposed in the accommodating space 13 of the housing 10 , and the fan blade 20 rotates counterclockwise. That is to say, the fan blade 20 rotates along the direction D and passes through the tongue section 1722 , the connecting section 1721 , the bypass opening 14 and the first wall portion 171 in sequence. The fan blade 20 sucks in air from the air inlet 11 located on the top plate 15 of the casing 10 , and generates an airflow in the accommodation space 13 of the casing 10 , and the generated airflow finally leaves through the air outlet 12 .

In this embodiment, the muffler tank 40 is made of a hard material such as plastic, and is disposed at the bypass opening 14 of the side wall 17 . The muffler tank body 40 has an airflow channel 41 , and the airflow channel 41 communicates with the accommodating space 13 through the bypass opening 14 . In detail, the muffler tank body 40 includes a long side plate 42, a short side plate 43, an upper side plate 45, a lower side plate 46 and a tank bottom plate 44, and the long side plate 42 includes an extension section 421 and a guide stream segment 422 . The long side plate 42, the short side plate 43, the upper side plate 45, the lower side plate 46 and the groove bottom plate 44 surround the air flow passage 41 together, and the extension section 421 of the long side plate 42, the short side plate 43, the upper side plate 45 and the lower The side plates 46 respectively connect different sides of the tank bottom plate 44 . The diversion section 422 of the long side plate 42, the short side plate 43, the upper side plate 45 and the lower side plate 46 are respectively arranged at each end of the bypass port 14, so that the muffler tank 40 is arranged at the bypass port 14 and located at Outside the accommodation space 13.

In this embodiment, the guide section 422 is, for example, an arc-shaped plate body, and the joint between the guide section 422 and the connecting section 1721 of the second wall 172 forms a smooth rounded design for guiding the fans. The airflow generated by the blade 20 passes through the bypass port 14 and enters the airflow channel 41 , so that the noise generated by the passing frequency of the blade 20 can be reduced. Furthermore, in this embodiment, the short side panels 43 have the same curvature as the first wall portion 171 , so that the entire short side panels 43 fit the first wall portion 171 . In this way, the arrangement of the short side panel 43 adhering to the first wall portion 171 can help the overall volume of the fan device 1 to be reduced, and can be arranged in a notebook computer with limited internal space.

In this embodiment, the sound-absorbing tank body 40 has short side panels 43 , which is not intended to limit the present invention. In other embodiments, if the sound-absorbing tank body is attached to the first wall, the sound-absorbing tank body may have no short side panels, and the airflow channel may be the long side panels, the first wall part, the upper side panel and the lower side panel. Surrounded by side panels.

Next, the noise reduction principle of the sound-absorbing tank body 40 will be described. Please refer to FIG. 3 . FIG. 3 is a schematic diagram of the sound-absorbing tank in FIG. 1 . The length L of the airflow passage 41 of the sound absorbing tank 40 depends on the blade passing frequency of the fan blade 20 . When the length L of the airflow passage 41 is a quarter of the wavelength λ of the passing frequency of the fan blade 20, the incident wave 60 formed when the airflow enters the airflow passage 41 will be reflected by the bottom of the sound-absorbing tank 40, resulting in the same amplitude But the reflected wave 70 is opposite in phase to the incident wave 60 . In this way, the phase difference between the incident wave 60 and the reflected wave 70 can produce destructive interference, thereby reducing the noise generated by the passing frequency of the fan blade 20 . For example, if the blade passing frequency of the fan blade 20 to be eliminated is 2145Hz, then the wavelength of the blade passing frequency of the fan blade 20 is sound velocity/frequency, that is, 342(m/s)/2145(Hz)=0.16(m) . Therefore, the length L of the airflow channel 41 of the sound-absorbing tank 40 is a quarter of the wavelength λ, that is, 0.16(m)/4=0.04(m), which is about 4 cm.

Next, the noise reduction effect of the sound-absorbing tank 40 of this embodiment is described by measuring the frequency spectrum generated by the fan device 1 with or without the sound-absorbing tank 40 . According to the experimental data, the blade passing frequency noise and the total noise value produced by the fan device 1 without the sound-absorbing tank 40 are about 35.6dB(A)/20uPa and 43.4dB(A)/20uPa respectively, while the sound-absorbing The blade passing frequency noise and the total noise generated by the fan device 1 in the tank 40 are about 26.8dB(A)/20uPa and 41.4dB(A)/20uPa respectively. Wherein, the total value noise is defined as the sum of all noise values of the fan device 1 at a frequency between 100 Hz and 20 kHz. Then, comparing the above-mentioned experimental data, the blade passing frequency noise produced by the fan device 1 with the sound-absorbing tank body 40 is reduced from 35.6dB(A)/20uPa to 26.8dB(A)/20uPa, and its total noise value is reduced from 43.4 dB(A)/20uPa drops to 41.4dB(A)/20uPa. Therefore, it can be seen from the above experimental data that the fan device 1 has an obvious noise reduction effect when it has the sound attenuation tank 40 .

In addition, the relationship between the position of the sound-absorbing tank 40 and the noise-reducing effect will be further discussed. As shown in FIG. 2 , a connection line S is first defined, and the connection line S is a plane P passing through the rotation axis R of the fan blade 20 and perpendicular to the air outlet 12 . In this embodiment, when the sound-absorbing groove body 40 and the tongue section 1722 are located on different sides of the connecting line S, the measured blade passing frequency noise and total value noise are respectively 26.8dB(A)/20uPa and 41.4dB(A)/20uPa. Conversely, if the sound-absorbing groove body 40 and the tongue section 1722 are located on the same side of the connecting line S, and the sound-absorbing groove body is arranged on the tongue section 1722, the measured blade passing frequency noise and total value noise are respectively 39.5dB( A)/20uPa and 44.9dB(A)/20uPa. Therefore, it can be seen that the sound-absorbing groove body 40 disposed on the other side of the connecting line S relative to the tongue-mouth section 1722 has a better noise-reducing effect.

In this embodiment, the sound-absorbing tank body 40 made of hard material can completely reflect the incident wave 60 and generate a reflected wave 70 with an amplitude equivalent to that of the incident wave 60, so that the incident wave 60 and the reflected wave 70 have a more destructive effect. Significantly, in order to improve the noise reduction effect of the sound-absorbing tank body 40, but not limited thereto. In other embodiments, the sound-absorbing tank can be made of soft materials, such as rubber tubes or soft plastics. In this way, if you want to install the sound-absorbing tank on the traditional fan and find that the space where the sound-absorbing tank is installed is insufficient, you can use the soft material to have the characteristics of being extendable and bendable, so that the sound-absorbing tank can be installed On the casing of a traditional fan.

In this embodiment, the fan device 1 further includes a porous material 50 . The porous material 50 is, for example, foam and is located between the diversion section 422 and the bypass port 14 . The porous material 50 can suppress the turbulent flow generated when the airflow hits the convex point where the short side plate 43 is connected with the first wall portion 171 , so as to reduce the noise generated by the turbulent flow. In addition, the porous material 50 has a plurality of air-permeable pores 51, which can help the airflow generated by the fan blade 20 enter the sound-absorbing groove 40, so as to reduce the noise generated by the passing frequency of the blade.

In detail, it can be known from experimental data that when the porous material 50 is placed between the guide section 422 and the bypass port 14, the total value noise in the frequency spectrum generated by the fan device 1 is about 40dB(A)/20u Pa is not only less than the total noise noise (43.4dB(A)/20u Pa) produced by the fan device 1 without the sound-absorbing tank body 40 and the porous material 50, but also smaller than that produced by the fan device 1 with only the sound-absorbing tank body 40 Gross noise (41.1dB(A)/20u Pa). Therefore, the porous material 50 can effectively suppress the turbulent flow generated when the airflow collides with the protruding point where the short side plate 43 and the first wall portion 171 join, so as to reduce the noise generated by the turbulent flow, so that the overall noise reduction effect of the fan device 1 is further improved. promote.

In this embodiment, the sound-absorbing tank body 40 is detachably mounted on the side wall 17 of the casing 10 by, for example, locking or screwing. In this way, if the fan device 1 is used for a long time, there is dust accumulation in the sound-absorbing tank 40 , which can be cleaned by removing the sound-absorbing tank 40 , so that the noise-reducing effect of the sound-absorbing tank 40 can be maintained. On the other hand, if the fan blade 20 is deformed after long-term use, after replacing the new fan blade 20, the new fan blade 20 will have a different blade passing frequency, so the original sound-absorbing tank 40 can be removed. And install the sound-absorbing groove body 40 of the 1/4th of the wavelength of the blade passing frequency of the new fan blade 20 with the length of the air flow passage 41, to maintain the noise-reducing effect of the sound-absorbing groove body 40.

In this embodiment, the detachable installation of the sound-absorbing tank body 40 on the side wall 17 of the casing 10 is just an example, but not limited thereto. In other embodiments, the sound-absorbing tank can be detachably installed on the top plate or the bottom plate of the casing, and the air flow channel communicates with the bypass port when the installation is completed. Alternatively, the sound-absorbing tank body can be integrally formed with the housing to increase the degree of sealing between the sound-absorbing tank body and the housing.

In addition, the aforementioned fan device 1 is an example of a centrifugal fan, but it is not limited thereto. In other embodiments, the fan device can be an axial fan, or other types of fan devices.

In this embodiment, the short side plate 43 of the sound attenuation tank 40 is disposed in close contact with the first wall portion 171 , but the present invention is not limited thereto. Please refer to FIG. 4 . FIG. 4 is a cross-sectional view of a fan device according to a second embodiment of the present invention. In this embodiment, the shape of the sound-absorbing tank 40' is a rectangular parallelepiped, and the sound-absorbing tank 40' extends away from the accommodation space 13' of the housing 10'. The length L2 of the airflow channel 41' of the sound-absorbing tank 40' is 1/4 of the wavelength of the passing frequency of the fan blade 20', so that the sound-absorbing tank 40' can reduce noise by the aforementioned principle.

According to the fan device disclosed in the above embodiment, the length of the airflow channel passing through the sound-absorbing tank body is a quarter of the wavelength of the passing frequency of the fan blade, so that the incident wave and the reflected wave generated by the airflow entering the airflow channel can cancel each other , to reduce the noise of the fan unit. In addition, when the sound-absorbing groove is arranged on the connecting line relative to the tongue section, it has a better noise-reducing effect.

In addition, the porous material can suppress the turbulent flow generated when the airflow collides with the convex point where the short side plate and the first wall part are joined, so as to reduce the noise generated by the turbulent flow. In addition, the porous material has a plurality of air-permeable pores, which can help the airflow generated by the fan blades to enter the sound-absorbing groove, so as to reduce the noise generated by the passing frequency of the blades.

Furthermore, the setting of the sound-absorbing tank and the shell made of hard materials can make the sound-absorbing tank reflect the incident wave completely, and generate a reflected wave with an amplitude equivalent to the incident wave, so that the cancellation effect of the incident wave and the reflected wave is more perfect. Significantly, in order to improve the noise reduction effect of the muffler tank.

In addition, through the arc-shaped plate body of the guide section and the smooth rounded corner design at the connection section between the guide section and the second wall, it can help the airflow generated by the fan blade to enter through the bypass port in the airflow channel.

In some embodiments, the sound-absorbing tank body can be made of soft material, so that the sound-absorbing tank body can still be installed on the casing by bending or extending in the case of insufficient installation space.

In addition, the sound-absorbing tank is detachably mounted on the casing, and can be cleaned by removing the sound-absorbing tank, so that the noise reduction effect of the fan device can be maintained. On the other hand, if the fan blade needs to be replaced with a new fan blade after long-term use, the original sound-absorbing tank can be removed, and a sound-absorbing tank body that meets the passing frequency of the new fan blade can be installed to maintain the fan device. noise reduction effect.

Claims (11)

1. A fan device, characterized in that the fan device comprises A casing, having an air inlet, an air outlet, an accommodating space and a bypass opening connected to each other; a fan blade arranged in the accommodating space; and A sound-absorbing tank, which is arranged at the bypass port and outside the accommodation space, the sound-absorbing tank has an airflow passage, and the airflow passage communicates with the accommodation space through the bypass opening; Wherein, the fan blade inhales air through the air inlet, and generates airflow in the accommodating space, so that the airflow passes through the bypass opening and enters the airflow channel. 2. The fan device according to claim 1, further comprising a porous material disposed at the bypass port, and the porous material has a plurality of ventilation holes through which the airflow generated by the fan blade passes. Breathable pores enter the airflow channel. 3 . The fan device according to claim 1 , wherein the length of the airflow channel is a quarter of the wavelength of the passing frequency of the fan blade. 4 . 4. The fan device according to claim 1, wherein the casing comprises a top plate, a bottom plate and a side wall, the top plate and the bottom plate are connected to opposite sides of the side wall, and the air inlet is located at The top plate, the top plate, the bottom plate and the side wall jointly surround the accommodating space and form the air outlet, the bypass port is located on the side wall, and the bypass port divides the side wall into a first wall part and a first wall Two wall parts, the second wall part has a connection section and a tongue section connected to each other, the connection section is connected to the bypass opening, and the tongue section is located at the end of the connection section away from the bypass opening. 5. The fan device according to claim 4, wherein a connection line is defined, the connection line passes through the rotation axis of the fan blade and is perpendicular to the plane where the air outlet is located, the bypass port and the tongue The segments are located on opposite sides of the line. 6. The fan device according to claim 1, wherein the sound-absorbing tank body comprises a long side plate, a short side plate, an upper side plate, a lower side plate and a slot bottom plate, and the long side plate comprises a connected An extension section and a guide section, the long side plate, the short side plate, the upper side plate, the lower side plate and the groove bottom plate jointly surround the air flow passage, and the extension section of the long side plate, the The short side plate, the upper side plate and the lower side plate should be respectively connected to different sides of the bottom plate of the trough, and the diversion section of the long side plate, the short side plate, the short side plate, the upper side plate and the The lower side plate is respectively connected to each end of the bypass port. 7 . The fan device according to claim 1 , wherein the sound attenuation tank is integrally formed with the casing. 8 . 8 . The fan device as claimed in claim 1 , wherein the sound attenuation tank is detachably mounted on the casing. 8 . 9. The fan device according to claim 1, wherein the sound-absorbing tank body is made of hard material. 10 . The fan device according to claim 1 , wherein the sound-absorbing tank body is made of soft material. 11 . 11. The fan device according to claim 1, wherein the porous material is foam.