CN108506231B

CN108506231B - Fan device

Info

Publication number: CN108506231B
Application number: CN201810249200.9A
Authority: CN
Inventors: 丁国基
Original assignee: Inventec Pudong Technology Corp; Inventec Corp
Current assignee: Inventec Pudong Technology Corp; Inventec Corp
Priority date: 2018-03-22
Filing date: 2018-03-22
Publication date: 2020-06-12
Anticipated expiration: 2038-03-22
Also published as: US20190293090A1; CN108506231A

Abstract

The invention discloses a fan device, which comprises a shell, a fan blade and a silencing groove body. The shell is provided with an air inlet, an air outlet, an accommodating space and a bypass opening which are communicated with each other. The fan blades are arranged in the accommodating space. The silencing groove body is arranged at the bypass opening and is positioned outside the accommodating space, and the silencing groove body is provided with an airflow channel which is communicated with the accommodating space through the bypass opening. The fan blades suck air through the air inlet and generate airflow in the accommodating space so that the airflow passes through the bypass port and enters the airflow channel.

Description

Fan device

Technical Field

The present invention relates to a fan device, and more particularly, to a fan device having a silencing tank.

Background

With the 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 performance of electronic devices, a lot of heat is generated, so that the temperature inside the electronic device is increased to affect the performance of the electronic device, and the heat dissipation method of the existing electronic device mostly relies on a heat dissipation fan to dissipate heat.

However, the heat dissipation fan of the electronic device generates noise due to the blade passing frequency (blade passing frequency), so that the user experience is reduced. Generally, the noise generated by the fan is solved by modifying the shape of the fan blades or the shape of the internal flow channel of the fan, but the currently adopted measures still have difficulty in completely eliminating the noise of the fan, so that the user still suffers from the noise of the fan.

Disclosure of Invention

The present invention provides a fan device, so as to solve the problem of fan noise that is still difficult to solve by modifying the shape of the fan blade or the shape of the internal flow channel of the fan in the prior art.

According to the fan device disclosed by the embodiment, the fan device is provided with the silencing groove body, so that the silencing groove body can reduce noise generated by the passing frequency of the blades of the fan blades, and the electronic device provided with the fan can improve the use sensitivity of a user.

The above description of the present invention and the following description of the embodiments are provided to illustrate and explain the spirit and principles of the present invention and to provide further explanation of the invention as claimed in the appended claims.

Drawings

Fig. 1 is a perspective view of a fan apparatus according to a first embodiment of the present invention.

Fig. 2 is a cross-sectional view of fig. 1.

Fig. 3 is a schematic view of the muffler tank of fig. 1.

Fig. 4 is a sectional view of a fan apparatus according to a second embodiment of the present invention.

Wherein, the reference numbers:

1 Fan device

10. 10' shell

11 air inlet

12 air outlet

13. 13' accommodating space

14 by-pass port

15 Top plate

16 bottom plate

17 side wall

171 first wall part

172 second wall part

1721 connecting segment

1722 tongue and groove section

20. 20' fan blade

40. 40' silencing groove body

41. 41' air flow channel

42 long side plate

421 extension segment

422 flow guiding section

43 short side plate

44 groove bottom plate

45 upper side plate

46 lower side plate

50 pore material

51 air gap

60 incident wave

70 reflected wave

P plane

R axle center

Direction D

L, L2 length

Lambda wavelength

S connecting line

Detailed Description

Please refer to fig. 1-2. Fig. 1 is a perspective view of a fan apparatus according to a first embodiment of the present invention. Fig. 2 is a cross-sectional view of fig. 1.

In the fan device 1 of the present embodiment, the fan device 1 is, for example, a centrifugal fan, and is applied to, for example, an electronic device such as a notebook computer. The fan device 1 includes a housing 10, a fan blade 20 and a sound-deadening tank 40.

The housing 10 is made of a hard material such as plastic, and has an air inlet 11, an air outlet 12, a receiving space 13 and a bypass 14. In detail, the housing 10 includes a top plate 15, a bottom plate 16 and a side wall 17, wherein the top plate 15 and the bottom plate 16 are connected to two 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 surround the accommodating space 13 together and form an air outlet 12. The bypass port 14 is located in the side wall 17. The side wall 17 is divided into a first wall portion 171 and a second wall portion 172 by the bypass opening 14, and the second wall portion 172 has a connecting section 1721 and a tongue section 1722 connected thereto. The connecting section 1721 is connected to the bypass port 14, and the tongue section 1722 is located at an end of the connecting section 1721 away from the bypass port 14.

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

In this embodiment, the silencing trough 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 slot 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 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 421 and a flow guiding 422. The long side plate 42, the short side plate 43, the upper side plate 45, the lower side plate 46 and the slot bottom plate 44 together surround the gas flow channel 41, and the extension 421 of the long side plate 42, the short side plate 43, the upper side plate 45 and the lower side plate 46 are respectively connected to opposite sides of the slot bottom plate 44. The flow guiding section 422, the short side plate 43, the upper side plate 45 and the lower side plate 46 of the long side plate 42 are respectively disposed at each end of the bypass opening 14, so that the muffler tank 40 is disposed at the bypass opening 14 and outside the accommodating space 13.

In the present embodiment, the flow guiding section 422 is, for example, an arc-shaped plate, and a connection portion between the flow guiding section 422 and the connection section 1721 of the second wall portion 172 forms a smooth fillet design for guiding the airflow generated by the fan blade 20 to enter the airflow channel 41 through the bypass opening 14, so as to reduce the noise generated by the blade passing frequency of the fan blade 20. Furthermore, in the present embodiment, the short side plates 43 have the same curvature as the first wall portion 171, so that the whole short side plates 43 are attached to the first wall portion 171. Therefore, the arrangement of the short side plate 43 attached to the first wall 171 can help the overall size of the fan device 1 to be reduced, and the fan device can be arranged in a notebook computer with limited internal space.

In the present embodiment, the muffler tank 40 has the short side plates 43, and is not intended to limit the present invention. In other embodiments, if the silencing groove is attached to the first wall, the silencing groove may have no short side plate, and the airflow channel may be surrounded by the long side plate, the first wall, the upper side plate and the lower side plate.

Next, the noise reduction principle of the muffler tank 40 will be explained. Referring to fig. 3, fig. 3 is a schematic diagram of the muffler tank of fig. 1. The length L of the air flow passage 41 of the muffler groove 40 is determined by the blade passing frequency (blade passing frequency) of the fan blade 20. When the length L of the airflow channel 41 is one quarter of the wavelength λ of the blade passing frequency of the fan blade 20, the incident wave 60 formed by the airflow entering the airflow channel 41 is reflected by the bottom of the sound-deadening tank 40, and a reflected wave 70 having the same amplitude but opposite phase to the incident wave 60 is generated. As such, the phase difference between the incident wave 60 and the reflected wave 70 may produce destructive interference, thereby reducing noise generated by the blade passing frequency of the fan blade 20. For example, if the blade passing frequency of the fan blade 20 to be eliminated is 2145Hz, the wavelength of the blade passing frequency of the fan blade 20 is sonic velocity/frequency, i.e., 342(m/s)/2145(Hz) ═ 0.16 (m). Therefore, the length L of the airflow channel 41 of the muffler groove body 40 is one quarter of the wavelength λ, i.e., 0.16(m)/4 is 0.04(m), which is about 4 cm.

Next, the noise reduction effect of the sound-deadening tank 40 of the present embodiment will be described by measuring the frequency spectrum generated by the presence or absence of the sound-deadening tank 40 of the fan device 1. From experimental data, the blade passing frequency noise and the total noise value generated by the fan device 1 without the sound-deadening tank 40 are respectively about 35.6db (a)/20u Pa and 43.4db (a)/20u Pa, and the blade passing frequency noise and the total noise value generated by the fan device 1 with the sound-deadening tank 40 are respectively about 26.8db (a)/20u Pa and 41.4db (a)/20u Pa. Wherein, the total noise is defined as the sum of all noise values of the fan device 1 between the frequency of 100Hz and 20 kHz. Then, comparing the above experimental data, the blade passing frequency noise generated by the fan apparatus 1 having the muffler groove 40 is reduced from 35.6dB (A)/20u Pa to 26.8dB (A)/20u Pa, and the total noise value is reduced from 43.4dB (A)/20u Pa to 41.4dB (A)/20u Pa. Therefore, it can be seen from the above experimental data that the fan apparatus 1 has a significant noise reduction effect when having the muffler tank 40.

In addition, the relationship between the position of the muffler tank 40 and the noise reduction effect will be discussed further. As shown in FIG. 2, a line S is defined, which passes through the rotation axis R of the fan 20 and is perpendicular to the plane P where the air outlet 12 is located. In the present embodiment, when the muffler slot 40 and the tongue portion 1722 are located on different sides of the connection line S, the measured blade passing frequency noise and the total value noise are 26.8db (a)/20u Pa and 41.4db (a)/20u Pa, respectively. On the contrary, if the sound-deadening groove 40 and the tongue section 1722 are located on the same side of the connection line S, and the sound-deadening groove is disposed on the tongue section 1722, the measured passing frequency noise and the total value noise of the blade are 39.5db (a)/20u Pa and 44.9db (a)/20u Pa, respectively. Therefore, it can be seen that the muffler groove 40 is disposed on the other side of the connecting line S relative to the tongue section 1722 to achieve better noise reduction effect.

In the present embodiment, the muffler tank 40 made of a hard material can completely reflect the incident wave 60 and generate the reflected wave 70 with an amplitude equivalent to that of the incident wave 60, so that the cancellation effect of the incident wave 60 and the reflected wave 70 is more significant, and the noise reduction effect of the muffler tank 40 is improved, but not limited thereto. In other embodiments, the sound-absorbing groove can be made of soft material, such as rubber tube or soft plastic. Therefore, if the silencing groove body is arranged on the traditional fan and the space where the silencing groove body is arranged is not enough, the silencing groove body can be arranged on the shell of the traditional fan by utilizing the extensible and bendable characteristics of the soft material.

In the present embodiment, the fan device 1 further includes a porous material 50. The porous material 50 is, for example, foam and is located between the flow guiding section 422 and the bypass opening 14. The porous material 50 can suppress turbulence generated when the air flow hits the protruding points of the short side plates 43 and the first wall portion 171, so as to reduce noise generated by the turbulence. 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 to enter the silencing groove body 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 disposed between the flow guiding section 422 and the bypass opening 14, the total noise in the frequency spectrum generated by the fan device 1 is about 40db (a)/20 upa, which is not only smaller than the total noise (43.4db (a)/20 upa) generated by the fan device 1 without the silencing groove 40 and the porous material 50, but also smaller than the total noise (41.1db (a)/20 upa) generated by the fan device 1 with only the silencing groove 40. Therefore, the aperture material 50 can effectively suppress the turbulence generated at the protruding point where the air flow hits the short side plate 43 and the first wall portion 171, so as to reduce the noise generated by the turbulence, and further improve the overall noise reduction effect of the fan device 1.

In the present embodiment, the sound-deadening tank body 40 is detachably mounted on the side wall 17 of the housing 10 by means of, for example, a tenon or a screw. In this way, if the fan device 1 is used for a long time, dust is accumulated in the muffler tank 40, and the muffler tank 40 can be removed for cleaning, so that the noise reduction effect of the muffler tank 40 can be maintained. On the other hand, if the fan blade 20 is deformed after long-term use, after the new fan blade 20 is replaced, the new fan blade 20 has a different blade passing frequency, so the original sound-deadening tank body 40 can be removed, and the sound-deadening tank body 40 with the length of the air flow channel 41 conforming to one-fourth of the wavelength of the blade passing frequency of the new fan blade 20 is installed, so as to maintain the noise reduction effect of the sound-deadening tank body 40.

In the present embodiment, the arrangement of the muffler groove 40 detachably mounted on the side wall 17 of the housing 10 is only for illustration, but not limited thereto. In other embodiments, the silencing trough body can be detachably mounted on the top plate or the bottom plate of the shell, and the air flow channel is communicated with the bypass port when the mounting is completed. Or the silencing groove body and the shell can be integrally formed so as to increase the sealing degree of the silencing groove body and the shell.

The fan device 1 is exemplified by a centrifugal fan, but is not limited thereto. In other embodiments, the fan device may be an axial fan, or other type of fan device.

In the present embodiment, the short side plate 43 of the muffler groove body 40 is disposed to be attached to the first wall 171, but not limited thereto. Referring to fig. 4, fig. 4 is a cross-sectional view of a fan device according to a second embodiment of the disclosure. In the present embodiment, the muffler tank 40 'is a rectangular parallelepiped tank, and the muffler tank 40' extends in a direction away from the accommodating space 13 'of the housing 10'. The length L2 of the airflow channel 41 'of the sound-deadening tank 40' is a quarter of the wavelength of the blade passing frequency of the fan blade 20 ', so that the sound-deadening tank 40' can reduce the noise by the aforementioned principle.

According to the fan device disclosed by the embodiment, the length of the airflow channel passing through the silencing groove body is one fourth of the wavelength of the passing frequency of the fan blade, so that incident waves and reflected waves generated when the airflow enters the airflow channel can be mutually cancelled, and the noise of the fan device is reduced. In addition, when the silencing groove body is arranged on the connecting line relative to the tongue mouth section, better noise reduction effect is achieved.

In addition, the porous material can inhibit the turbulent flow generated by the air flow impacting the salient point of the short side plate and the first wall part, so as to reduce the noise generated by the turbulent flow. In addition, the pore material is provided with a plurality of air-permeable pores, which can help the airflow generated by the fan blade to enter the silencing groove body so as to reduce the noise generated by the passing frequency of the blade.

Moreover, the amortization cell body is the setting of hard material with the casing, can make the amortization cell body reflect the incident wave completely to produce the back wave equivalent with the incident wave amplitude, make the incident wave more showing with the effect that the back wave is destructive, in order to promote the effect that the amortization cell body was fallen and is made an uproar.

In addition, the design that the flow guide section is an arc-shaped plate body and the connecting part of the flow guide section and the connecting section of the second wall part is a smooth fillet guide can help the airflow generated by the fan blade to enter the airflow channel through the bypass opening.

In some embodiments, the sound-absorbing groove body may be made of soft material, so that the sound-absorbing groove body can be installed on the housing by bending or extending when the installation space is insufficient.

In addition, the silencing groove body is detachably arranged on the shell, and can be cleaned in a mode of detaching the silencing groove body, 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 by a new fan blade after long-term use, the original silencing groove body can be detached, and the silencing groove body which accords with the blade passing frequency of the new fan blade is mounted, so that the noise reduction effect of the fan device is maintained.

Claims

1. A fan device is characterized in that the fan device comprises

A shell, which is provided with an air inlet, an air outlet, an accommodating space, a bypass port and a tongue port section which are communicated with each other;

a fan blade arranged in the accommodating space;

the silencing groove body is arranged at the bypass opening and positioned outside the accommodating space, and is provided with an airflow channel which is communicated with the accommodating space through the bypass opening; and

a porous material arranged at the side port and provided with a plurality of air permeable pores, and the airflow generated by the fan blade passes through the air permeable pores and enters the airflow channel;

wherein the fan blade sucks air through the air inlet and generates airflow in the accommodating space so as to enable the airflow to pass through the bypass port and enter the airflow channel,

wherein, a connecting line is defined, the connecting line passes through the rotating axes of the fan blades and the air outlet of the shell and is vertical to the plane where the air outlet is positioned, all the by-pass ports and the tongue opening section are respectively positioned at two opposite sides of the connecting line,

wherein the length of the air flow channel is one fourth of the wavelength of the blade passing frequency of the fan blade,

this amortization cell body contains a long curb plate, a short curb plate, an upper plate, curb plate and a bottom plate of a groove, this long curb plate contains an extension section and a water conservancy diversion section that links to each other, this long curb plate, this short curb plate, this upper plate, this lower curb plate and this bottom plate encircle this airflow channel jointly, and this extension section of this long curb plate, this short curb plate, this upper plate and this bottom plate of this side plate connect the different sides of this bottom plate of a groove respectively, this water conservancy diversion section of this long curb plate, this short curb plate, this upper plate and this lower curb plate connect the each end of this by-pass opening respectively.

2. The fan apparatus as claimed in claim 1, wherein the housing 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, the air inlet is located on the top plate, the bottom plate and the side wall jointly surround the accommodating space and form the air outlet, the bypass opening is located on the side wall, the bypass opening is divided into a first wall portion and a second wall portion, the second wall portion has a connecting section and the tongue section connected to each other, the connecting section is connected to the bypass opening, and the tongue section is located at an end of the connecting section away from the bypass opening.

3. The fan apparatus as claimed in claim 1, wherein the muffler tank is integrally formed with the housing.

4. The fan apparatus as claimed in claim 1, wherein the muffler tank is detachably mounted to the housing.

5. The fan apparatus as claimed in claim 1, wherein the muffler tank is made of a hard material.

6. The fan apparatus as claimed in claim 1, wherein the muffler tank is made of a soft material.

7. The fan apparatus as claimed in claim 1, wherein the porous material is foam.