JP2005214107A - Fan device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fan device reducing noise. <P>SOLUTION: An upper blade 6 and a lower blade 7 are arranged to be shifted from each other in the rotational direction of an impeller 5. Thereby, sound periodically produced by a tongue 3c and sound periodically produced by a tongue 4c are canceled. As a result, noise generated from the fan device 1 can be reduced. Besides, the upper blade 6 and the lower blade 7 are integrally arranged, therefore, only one motor 10 is enough, and noise can be reduced in comparison with the case of independent driving by two motors. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a fan device for cooling an electronic device.

  Conventionally, a heat generating device such as a PC (Personal Computer) is equipped with a fan for exhausting the heat. For example, there is a CPU (Central Processing Unit) mounted on a PC as a heat source. As a general fan, for example, there is a fan in which an impeller rotated by a motor is accommodated in a case provided with an intake port and an exhaust port. As the impeller rotates in the case, the air sucked from the intake port is discharged from the exhaust port.

By the way, since such a fan uses a motor to rotate the impeller, its noise becomes a problem. Further, the wind noise generated when the impeller rotates increases as the rotation speed increases, resulting in noise. In order to reduce such noise, there is a technique in which two fans are prepared and the noise waveform is synthesized by approximating the time lapse of the fan noise waveform to a sine wave. (For example, refer to Patent Document 1).
JP 2001-85881 A (paragraph [0016], FIG. 1)

  However, it is difficult to reduce noise only by adjusting the phase of the rotational speed of the fan in the technique described in Patent Document 1. This is because when the fan is operated, wind noise, motor noise, and other noises are actually mixed. Further, FIG. 3 of Patent Document 1 discloses a technique for collecting noise of a fan with a microphone and analyzing the frequency of the sound to generate a synthesized wave to reduce noise. To be complicated.

  In recent years, the increase in CPU frequency has become even more prominent, and the amount of heat generation is also increasing. Therefore, it is necessary to further increase the cooling efficiency of the CPU in the future. To increase the cooling efficiency, it is conceivable to increase the impeller and increase the air volume by increasing the rotation speed, but on the other hand, the motor noise and impeller wind noise also increase, Not suitable for downsizing and downsizing.

  In view of the circumstances as described above, an object of the present invention is to provide a fan device that can reduce noise.

  Another object of the present invention is to provide a fan device that is improved in cooling efficiency and reduced in thickness or size.

  In order to achieve the above object, a fan device according to the present invention is provided with a first case having a first tongue portion therein, and is rotatably provided in the first case. A first blade provided to approach the first tongue, a second case provided adjacent to the first case and having a second tongue therein, and the second The first blade is disposed in the case so as to approach the second tongue with a period that cancels out a sound generated when the first blade approaches the first tongue. And a second blade that rotates coaxially and integrally.

  In the present invention, the sound periodically generated in the first tongue and the sound periodically generated in the second tongue are canceled out. Thereby, the noise which generate | occur | produces from a fan apparatus can be reduced. In addition, since the first blade and the second blade are rotated together, a single drive unit such as a motor is sufficient. Therefore, noise can be reduced as compared with the case where the first blade and the second blade are driven by separate drive units. In addition, since both the first blade and the second blade are provided, the amount of gas supplied by the fan device is increased, and the cooling efficiency can be improved.

  The present invention has been made by paying attention to the fact that the main factor of the noise of the fan device is the sound generated when the blade approaches the tongue of the case. Therefore, in order to cancel out the generated sounds, for example, by optimizing the timing at which the first and second blades approach the first and second tongues, respectively, it is caused only by the tongues. Noise can be minimized.

  In the present invention, the first tongue is a portion where the pressure is increased by the rotation of the first blade inside the first case, and the first blade and the inner wall of the first case (the flow of gas) (The wall forming the path) is the closest part. The second tongue is the same as the first tongue.

  To cancel the sound means that the amount of synthesized sound generated by the first tongue and the second tongue is weakened. That is, it means that the sound pressure level of the synthesized sound is lower than the sound generated only from the first tongue (or the sound generated only from the second tongue). Also, in part or all of the area in the space where the sound wave generated from the first tongue (or the second tongue) is propagated, the sound wave cancels each other or weakens each other. It means to include. This is because there are places where they can be strengthened depending on the distance between the two sound sources. When the wavelength of the sound wave is λ, the distance between the two sound sources, that is, the distance between the first tongue and the second tongue is, for example, 2 / λ or less. There will be no points to strengthen and cancel each other.

  According to an aspect of the present invention, a plurality of the first blades and the second blades are provided, and are arranged so as to be shifted from each other in the rotation direction of the first and second blades. Thereby, the phase of each sound wave which generate | occur | produces in the 1st and 2nd tongue part can be controlled suitably.

  According to an aspect of the present invention, the first tongue and the second tongue are disposed at substantially the same position in the rotation direction, and the first blade and the second blade are configured to rotate the rotation. Alternatingly arranged at approximately the same interval in the direction. As a result, the phase of the two sounds can be shifted by approximately 180 degrees, so that the noise can be reduced. The substantially same position in the rotation direction indicates that the first blade and the second blade are arranged in parallel in a direction substantially parallel to the rotation axes of the first and second blades.

  According to one form of this invention, the said 1st tongue part and the 2nd tongue part are mutually shifted | deviated and arrange | positioned in the rotation direction of the said 1st and 2nd braid | blade. Thus, noise can be reduced by making the relative positions of the first and second tongue portions suitable. In this case, the relative positions of the first and second blades in the rotational direction can also be set as appropriate. For example, the first and second blades may be at substantially the same position in the rotational direction or at different positions.

  According to an aspect of the present invention, the first case has a first opening, the second case has a second opening facing the first opening, A connecting plate is provided between the first opening and the second opening and integrally connects the first and second blades. As a result, the first and second blades can be integrally formed, and the connecting plate can also be used as a partition plate for partitioning the inside of the first case and the inside of the second case. The fan device can be configured with a simple structure.

  According to an aspect of the present invention, the first case and the second case have a first exhaust port and a second exhaust port, respectively, and the first exhaust port and the second exhaust port are provided. The exhaust ports are arranged so as to be shifted from each other in the rotational direction. Since it is only necessary to shift the relative positions of the first exhaust port and the second exhaust port according to the relative positions of the first tongue and the second tongue, the fan device can be easily designed. Become.

  According to one aspect of the present invention, it further includes a first heat radiating member provided near the first exhaust port and a second heat radiating member provided near the second exhaust port. Since air is exhausted in two directions via the first and second exhaust ports, the heat dissipation efficiency can be increased by providing the first and second heat dissipating members at these exhaust ports, respectively.

  A fan device according to another aspect of the present invention is provided adjacent to each other, and includes a plurality of cases each having a tongue portion therein, and a sound generated when the tongue portion periodically approaches by rotating. Each blade includes a plurality of blades that rotate coaxially and integrally within each case so as to cancel each other.

  In the present invention, a plurality of blades that rotate coaxially and integrally in each case are provided so as to cancel each other the sounds generated when the tongue is periodically approached. Noise can be reduced. The number of cases may be 3 or more. For example, if the number of cases is three, noise can be suitably reduced by shifting the three blades so that they have substantially the same pitch in the rotational direction. That is, the phases of the three sound waves may be shifted by 120 degrees. However, 120 degrees is an optimal arrangement and is not limited to this.

  As described above, according to the present invention, noise of the fan device can be reduced, the cooling efficiency can be improved, and the fan device can be reduced in thickness or size.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a fan device according to a first embodiment of the present invention. 2 is an exploded perspective view of the fan device shown in FIG. 1, and FIG. 3 is a cross-sectional view taken along line AA of FIG.

  The fan device 1 is configured by an impeller 5 being housed in an upper case 3 as a first case and a lower case 4 as a second case. The upper case 3 is fitted with a cover 2 provided with an air inlet 2a. As shown in FIG. 2, the impeller 5 has an upper blade 6 as a first blade and a lower blade 7 as a second blade. A plurality of upper blades 6 and lower blades 7 are provided, and the surfaces of the blades 6 and 7 are provided perpendicular to the rotational direction of the impeller 5. That is, it has the same shape as the centrifugal blade. These blades 6 and 7 are connected by a connecting plate 8 and are integrally formed.

  In the center of the impeller 5, a motor housing portion 9 for housing the motor 10 is formed as shown in FIG. The motor 10 includes a shaft 11, a bearing 12, a coil 14, a magnet 13, and the like. For example, the magnet 13 is fixed inside the motor housing 9 of the impeller 5. The shaft 11 is fixed to the impeller 5 at the top. The impeller 5 rotates by driving the motor 10 configured as described above. That is, the upper blade 6 and the lower blade 7 are coaxially and integrally rotated.

  As shown in FIG. 2, the upper case 3 is formed with a tongue portion 3 c, an upper surface portion 3 f is opened, and a gas scroll portion 3 g is provided. A gas exhaust port 3 a is provided on the side of the upper case 3. Similarly, the lower case 4 has a tongue 4c, an upper surface 4f is opened, and a gas scroll 4g is provided. Further, the bottom 4e of the lower case 4 is provided with an intake port 4b, and the side portion is provided with an exhaust port 4a. As shown in FIG. 4, the tongue 3 c and the tongue 4 c are arranged at the same position in the rotation direction R of the impeller 5. Further, the upper blade 6 and the lower blade 7 are arranged so as to be shifted from each other at substantially the same distance P in the rotation direction R of the impeller 5.

  As shown in FIGS. 2 and 3, an opening 3b is provided in the bottom 3e of the upper case. The upper case 3 and the lower case 4 are disposed adjacent to each other so that the opening 3b and the opening (opening) for forming the scroll portion 4g of the upper surface portion 4f of the lower case 4 face each other. Thereby, the inside of the upper case 3 communicates with the inside of the lower case 4. As shown in FIG. 3, the impeller 5 is accommodated in the upper and lower cases 3 and 4 so that the connecting plate 8 is positioned at the height of the opening 3b. As a result, the connecting plate 8 functions as a partition between the inside of the upper case 3 and the inside of the lower case 4. Thus, the impeller 5 according to the present embodiment is formed integrally, and the fan device 1 can be configured with a simple structure by using the connecting plate 8 as a partition plate.

  The operation of the fan device 1 configured as described above will be described. When the motor 10 is driven, the impeller 5 rotates, and air is taken into the upper case 3 and the lower case 4 from the intake ports 2a and 4b, respectively. The taken-in air is discharged from the exhaust ports 3a and 4a by the rotation of the impeller 5. The discharged air is blown onto, for example, a radiating fin (not shown), thereby promoting the action of releasing heat from the radiating fin.

  Since the upper blade 6 and the lower blade 7 are alternately arranged at the same interval, the rotation of the impeller 5 causes the upper blade 6 and the lower blade 7 to alternate between the tongue 3c and the tongue 4c at the same time interval. To approach. Thereby, the noise of the fan apparatus 1 can be reduced.

  Fig.5 (a) is a conceptual diagram which shows the waveform of the noise which generate | occur | produces when air hits the tongue parts 3c and 4c. The vertical axis represents noise amplitude (change in air pressure), and the horizontal axis represents time. This waveform pays attention only to the noise component generated when air hits the tongues 3c and 4c, and does not take into account the noise of the motor, the noise of the airflow in parts other than the tongue, and the like. Further, the magnitude (level) of the noise is expressed by the magnitude of the amplitude in this way. The smaller the amplitude, the smaller the noise. In the figure, waveform E is noise generated from the tongue 3 c of the upper case 3, and waveform F is noise generated from the tongue 4 c of the lower case 4. Thus, the waveform U according to the present embodiment, which is a combined wave of the waveforms E and F whose phases are shifted by 180 degrees, has an amplitude of zero or close to zero. That is, it is countered or weakened. For this reason, as shown in FIG.5 (b), a noise is reduced compared with the waveform T in which the sound was strong in the same phase in the conventional fan apparatus, for example.

  As described above, in the present embodiment, the sound periodically generated in the tongue 3c and the sound periodically generated in the tongue 4c are canceled out. Thereby, the noise which generate | occur | produces from the fan apparatus 1 can be reduced. Moreover, since the upper blade 6 and the lower blade 7 are integrally provided, it is sufficient to prepare one motor 10, and noise can be reduced as compared with the case where the two blades are independently driven. . In addition, since both the upper blade 6 and the lower blade 7 are provided, the amount of gas supplied by the fan device 1 is increased, and the cooling efficiency of electronic components, for example, can be improved.

  FIG. 6 is a perspective view showing a fan device according to the second embodiment of the present invention, and FIG. 7 is an exploded perspective view thereof. In the embodiments described below, the description of the same parts as those of the fan device 1 according to the first embodiment will be simplified or omitted, and different parts or functions will be mainly described.

  The fan device 21 includes a cover 22, an upper case 23, and a lower case 24. As shown in FIG. 7, the upper impeller 25A is accommodated in the upper case 23 provided with the tongue 23c. A lower impeller 25B is accommodated in the lower case 24 provided with the tongue 24c. Holes 39 and 29 are formed at substantially the center of each of the impellers 25A and 25B, and a hole 23b is formed at the substantially center of the bottom surface portion 23e of the upper case 23. The shaft 11 serving as the rotation shaft of the motor 10 is inserted into the holes 29, 23b and 29, and the shaft 11 is fixed to the upper impeller 25A and the lower impeller 25B. By driving the motor 10, the upper impeller 25A and the lower impeller 25B rotate integrally inside the cases 23 and 24, respectively. That is, it rotates integrally as an impeller 25 (see FIG. 6).

  The lower case 24 is attached to the upper case 23 so that the tongue 23c and the tongue 24c are arranged at substantially the same position in the rotational direction of the impeller 25. Further, as shown in FIG. 4, the blades 26 of the impeller 25 </ b> A and the blades 27 of the impeller 25 </ b> B are arranged on the shaft 11 so as to be displaced from each other at substantially the same interval in the rotation direction R of the impeller 25. Each is fixed.

  Also in the present embodiment, since the blades 26 and the blades 27 are alternately arranged at the same interval, the blades 26 and the blades 27 are alternately arranged at the same time interval by the rotation of the impeller 25. It approaches the part 24c. Thereby, the sound generated in the tongue 23c and the sound generated in the tongue 24c cancel each other, and the noise of the fan device 21 can be reduced.

  FIG. 8 is a perspective view of a fan device according to the third embodiment of the present invention. FIG. 9 is an exploded perspective view thereof, and FIG. 10 is a plan view of the fan device shown in FIG.

  The fan device 41 includes a cover 42, an upper case 43, and a lower case 44. Except for the attachment portion 55 to which the coil 14 of the motor 10 and the like are attached in the lower case 44, the upper case 43 and the lower case 44 have substantially the same shape. As shown in FIG. 10, the upper case 43 and the lower case 44 are attached so that the tongues 43 c and 44 c are displaced from each other in the rotational direction of the impeller 45. The impeller 45 is integrally formed by connecting an upper blade 46 and a lower blade 47 by a connecting plate 48. Similar to the example shown in FIG. 3, the impeller 45 is accommodated in the upper case 43 and the lower case 44 so that the connecting plate 48 and the bottom surface portion 43 e of the upper case are substantially flush with each other.

  As shown in FIG. 10, the upper blades 46 and the lower blades 47 are arranged so that the timings when the blades approach the tongue portion 43c and the tongue portion 44c are substantially equal. That is, the upper blade 46 and the lower blade 47 are arranged so that the upper blade 46 approaches the tongue portion 43c, and then the lower blade 47 approaches the tongue portion 44c, and so on. Has been. As a result, the sounds generated by the tongue portions 43c and 44c can be canceled with each other, and the noise of the fan device 41 can be reduced. The relative arrangement of the blades 46 and 47 can be set as appropriate depending on the number of rotations of the motor 10, the size of the impeller 5 (the diameter of the connecting plate 48, etc.), and the like. Depending on the number of rotations of the motor 10, the size of the impeller 5, or the relative arrangement of both tongues, the upper blade 46 and the lower blade 47 do not necessarily have to be shifted from each other in the rotational direction R.

  In the present embodiment, it is only necessary to shift the relative positions of the exhaust port 43a and the exhaust port 44a according to the relative positions of the tongue portions 43c and 44c, so that the fan device 41 can be easily designed.

  FIG. 11 is a view showing an example in which a heat radiating fin is attached to the fan device 41. Specifically, radiating fins 53 and 54 are attached to the exhaust ports 43a and 44a of the fan device 41, respectively. Thus, exhaust efficiency can be improved by providing two exhaust ports. Since the heat radiating fins 53 and 54 are attached to the respective exhaust ports 43a and 44a, the discharged air is blown to the heat radiating fins 53 and 54, the heat radiating action is promoted, and the heat radiating efficiency can be improved.

  The present invention is not limited to the embodiment described above, and various modifications are possible.

  For example, the impeller 5 shown in FIG. 2 may be comprised by an upper blade | wing, a middle blade | wing, a lower blade | wing, and two connection plates. In this case, three cases are required.

  Further, the shape of the case, the impeller, and the like are not limited to the above embodiment.

1 is a perspective view showing a fan device according to a first embodiment of the present invention. It is a disassembled perspective view of the fan apparatus shown in FIG. It is the sectional view on the AA line in FIG. It is a top view of the fan apparatus shown in FIG. It is a conceptual diagram which shows the waveform of the noise which generate | occur | produces when air hits both tongue parts. It is a perspective view which shows the fan apparatus which concerns on the 2nd Embodiment of this invention. It is a disassembled perspective view of the fan apparatus shown in FIG. It is a perspective view of the fan apparatus which concerns on the 3rd Embodiment of this invention. It is a disassembled perspective view of the fan apparatus shown in FIG. It is a top view of the fan apparatus shown in FIG. It is a perspective view which shows the example which attached the heat radiating fin to the fan apparatus shown in FIG.

Explanation of symbols

R: Rotational direction P: Spacing 1, 21, 41 ... Fan device 3, 23, 43 ... Upper case 3c, 23c, 43c ... Tongue 3a, 23a, 43a ... Exhaust port 3b ... Opening 4, 24, 44 ... Lower Case 4c, 24c, 44c ... tongue 4b ... intake port 6, 26, 46 ... upper blade 7, 27, 47 ... lower blade 8, 48 ... connecting plate 25A ... upper impeller 25B ... lower impeller

Claims (8)

A first case having a first tongue inside;
A first blade provided rotatably in the first case, and provided so as to periodically approach the first tongue by rotating;
A second case provided adjacent to the first case and having a second tongue inside;
The first case is provided in the second case so as to approach the second tongue with a period that cancels out a sound generated when the first blade approaches the first tongue. And a second blade that rotates coaxially and integrally with the first blade. The fan device according to claim 1,
A fan device, wherein a plurality of the first blades and the second blades are provided and are shifted from each other in the rotation direction of the first and second blades. The fan device according to claim 2,
The first tongue and the second tongue are disposed at substantially the same position in the rotational direction of the first and second blades;
The fan device, wherein the first blade and the second blade are alternately arranged at substantially the same interval in the rotation direction. The fan device according to claim 1,
The fan device, wherein the first tongue portion and the second tongue portion are arranged so as to be shifted from each other in the rotational direction of the first and second blades. The fan device according to claim 1,
The first case has a first opening;
The second case has a second opening facing the first opening;
A fan device further comprising a connecting plate provided between the first opening and the second opening and integrally connecting the first and second blades. It is a fan apparatus of Claim 4, Comprising:
The first case and the second case have a first exhaust port and a second exhaust port, respectively.
The fan device, wherein the first exhaust port and the second exhaust port are arranged to be shifted from each other in the rotation direction. The fan device according to claim 6,
A first heat dissipating member provided in the vicinity of the first exhaust port;
And a second heat dissipating member provided in the vicinity of the second exhaust port. A plurality of cases provided adjacent to each other, each having a tongue portion inside,
A plurality of blades that rotate coaxially and integrally in each case so as to cancel each other the sounds generated when the tongue is periodically approached by rotating. Fan device.

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