JP2008066507A - Cooling apparatus, and electronic appliance using same cooling apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling apparatus which reduces the noises generated when cooling by an air blower the inside of an electronic appliance and when cooling by an air blower a heat generating body present in a case. <P>SOLUTION: The cooling apparatus comprises an exhausting path 1 provided in the periphery of a heat generating body present inside the apparatus and an air blowing means 2 provided at one end of the exhausting path. This apparatus cools the heat generating body by the air blow of the air blowing means, and has slits 11 in the side surfaces of the exhausting path. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electronic device device that requires cooling and a cooling device for a heating element, and more particularly to a technique for reducing noise in the cooling device.

As a conventional cooling device, a device in which the periphery of the blower and the blower passage are covered with a porous sound-absorbing material and soundproofing measures are taken has been proposed. This cooling device is shown in FIGS. FIG. 9 is a perspective view showing a conventional cooling device, and FIG. 10 is a side sectional view thereof. In the figure, 1 is a discharge path for assembling a plate member 1a made of a porous material, 2 is a blower, and 3 is a heating element. The conventional cooling device includes a discharge path 1 in which a blower 2 and a heating element 3 are surrounded by a plate member 1a made of a porous material. The heat generated in the heating element 3 is discharged by the blower 2.
The air column resonance frequency f due to the sound pressure distribution of the cooling device can be expressed by the following equation (1) based on FIG.
Air column resonance frequency f = mc / 2L (1)
Where m = 1, 2, 3,..., C = sonic velocity (m / s), and L is the length of the discharge path 1.
On the other hand, the noise frequency generated from the blower 2 can be expressed by the following equation (2).
Noise frequency F = (Number of rotations of the blower) × (Number of blades of the blower) (2)
In the cooling device that cools the heating element 3 existing in the discharge path 1 by the air discharged by the blower 2, if the air column resonance frequency of the discharge path 1 and the noise frequency generated from the blower 2 coincide, The level is maximum.
As another conventional example, there is one provided with a duct that guides exhausted air to the lower part of the apparatus and exhausts the air downward (see, for example, Patent Document 1). FIG. 11 is a cross-sectional view of a cooling device showing another conventional example. In this cooling device, the air staying in the electronic device device 5 is discharged to the outside by the blower 2.
Japanese Patent Laid-Open No. 10-56280 (page 5-6, FIG. 1)

However, the conventional cooling device has a problem that, as a measure against noise, when surrounding the air blower and the air passage with a porous sound absorbing material to prevent sound, an extra space must be secured for the sound absorbing material. there were. In addition, when the air column resonance frequency of the discharge channel matches the noise frequency generated from the blower, the noise level becomes maximum, and there is a problem that the sound absorbing material cannot absorb sound.
The present invention has been made in view of such problems, eliminates an extra space for installing a sound absorbing material, greatly changes the air column resonance frequency of the discharge path, and the noise frequency of the blower. An object of the present invention is to provide a cooling device that can avoid the interference.

In order to solve the above problems, the present invention is configured as follows.
The invention according to claim 1 includes a discharge path provided around a heating element in the apparatus and a blowing means provided at one end of the discharge path, and the heating element is cooled by an air flow of the blowing means. In the cooling device, a slit is provided on a side surface of the discharge path.
Further, the invention according to claim 2 is constituted by a blowing unit provided in the electronic device and a discharge path provided in the blowing unit, and discharges the air staying inside the electronic device to the outside of the device. In the cooling device that cools the electronic device device by the above, a slit is provided on the side surface of the discharge path.
According to a third aspect of the present invention, the slit has a louver shape that makes it difficult for wind to escape to the outside.
According to a fourth aspect of the present invention, the member forming the discharge path is a porous material.
According to a fifth aspect of the present invention, the heating element is composed of a discharge path provided around a heating element in the apparatus and a blowing means provided at one end of the discharging path, and the heating element is cooled by an air flow of the blowing means. In the cooling device, a reflection plate is provided at the outlet of the discharge path to change the air flow in the lateral direction by providing a gap with an end of the discharge path.
According to a sixth aspect of the present invention, the heating element is composed of a discharge path provided around a heating element in the apparatus and a blowing means provided at one end of the discharging path, and the heating element is cooled by the air flow of the blowing means. In the cooling device, a partition plate having a minute hole is provided in the longitudinal direction inside the discharge passage.
A seventh aspect of the present invention is an electronic apparatus configured using the cooling device according to the first to seventh aspects.
It is.

According to the first to fourth aspects of the present invention, since the air column resonance frequency shifts to the high frequency region by providing the slit on the side surface of the discharge path, the interference with the noise frequency of the blower can be eliminated. Noise can be reduced without installing a sound absorbing material.
According to the fifth aspect of the present invention, the sound pressure distribution can be changed by providing a reflector perpendicular to the discharge path at the discharge path outlet, so that the air column resonance frequency and the noise frequency of the blower can be changed. Interference can be eliminated, and noise can be reduced without installing a sound absorbing material.
According to the invention described in claim 6, by providing the partition plate having micropores inside the discharge passage, by absorbing sound in the space between the partition plate and the discharge passage, it does not leak sound to the outside and is inexpensive. Therefore, noise can be reduced without installing a sound absorbing material.
According to the seventh aspect of the invention, an inexpensive and low-noise electronic device can be obtained.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view of a cooling device showing Embodiment 1 of the present invention, and FIG. 2 is a sectional view thereof. In the figure, reference numeral 11 denotes a slit, and the other reference numerals are the same as those in the prior art, and the description thereof is omitted.
In this embodiment, a slit 11 is provided on the upper surface of the discharge path 1.
The part where the present invention is different from the prior art is a part provided with a slit 11 in the discharge path 1.

  By providing the slit 11, the sound pressure distribution changes from the conventional sound pressure distribution (FIG. 10). Due to the change in the sound pressure distribution, the air column resonance frequency shifts to a high frequency region, so that interference with the noise frequency of the blower 2 can be eliminated.

FIG. 3 is a cross-sectional view of a cooling device showing Embodiment 2 of the present invention. In the figure, reference numeral 5 denotes an electronic device, and other reference numerals are the same as those in the prior art.
The cooling device of the present embodiment cools the electronic device device 5 by discharging the air staying inside the electronic device device 5 to the outside of the device with the blower device 2 using the discharge path 1 as a passage. A discharge path 1 for air discharged by the blower 2 and a slit 11 are provided on a side surface of the discharge path 1.
By providing the slit 11, the sound pressure distribution changes from the conventional sound pressure distribution (FIG. 10) as in the first embodiment, and interference with the noise frequency of the blower 2 can be eliminated.

  FIG. 4 is a cross-sectional view of a cooling device showing Embodiment 3 of the present invention. In the figure, the slit 11 of the discharge path 1 has a louver shape. By making the slit 11 of the discharge path 1 into a louver shape, it becomes difficult for the wind to escape to the outside, and noise can be eliminated without impairing the cooling efficiency.

  FIG. 5 is a cross-sectional view of a cooling device showing Embodiment 4 of the present invention. In the figure, 12 is a porous material. By providing the slit 11 in the discharge path 1, a high-frequency wind noise may occur. The porous material 12 is put on the slit 11 of the discharge path 1 through a gap to prevent the wind noise. Thereby, both the low frequency noise by the rotation speed of the air blower 2 and the high frequency noise by a wind noise can be reduced.

FIG. 6 is a perspective view of a cooling device showing Embodiment 5 of the present invention. In the figure, 13 is a reflector. A reflection plate 13 is provided at the outlet of the discharge path 1 perpendicularly to the discharge path 1, and the reflection plate 13 has a gap with respect to the outlet of the discharge path 1 so that the air flow can escape in the lateral direction. FIG. 7 shows a cross-sectional view of the cooling device of this embodiment and the sound pressure distribution in the discharge passage 1.
The part where the present invention is different from the prior art is a part provided with a reflector 13 perpendicular to the discharge path 1.

FIG. 7 is a cross-sectional side view of FIG. 6, showing the sound pressure distribution. The air column resonance frequency by the sound pressure distribution of the present embodiment can be expressed by the following equation (3).
Air column resonance frequency f = (2n + 1) c / 4L (3)
Where n = 0, 1, 2,..., C = sonic velocity (m / s)

  When the air column resonance frequency of the discharge path 1 and the noise frequency generated from the blower 2 coincide with each other, the noise level becomes maximum, but the sound pressure distribution of the prior art shown in FIG. The sound pressure distribution changes to the sound pressure distribution of the fifth embodiment shown in FIG. Due to the change in the sound pressure distribution, interference between the air column resonance frequency and the noise frequency of the blower 2 can be eliminated.

FIG. 8 is a perspective view of a cooling device showing Embodiment 6 of the present invention. In the figure, a partition plate 14 is provided inside the discharge passage 1, and the partition plate 14 has a microhole 15.
The part in which the present invention is different from the prior art is a part provided with a partition plate 14 having a minute hole 15 inside the discharge passage 1.

  When the air column resonance frequency of the discharge channel 1 and the noise frequency generated from the blower 2 coincide with each other, the noise level is maximized. However, since the partition plate 14 is provided, the microholes 15 of the partition plate 14 cause Helmholtz resonance effect By absorbing the sound and absorbing the sound in the partition plate 14 and the space 16 of the discharge path 1, an inexpensive soundproof structure that does not leak sound to the outside can be obtained.

The perspective view of the cooling device which shows Example 1 of this invention 1 is a side sectional view of FIG. Side sectional view of a cooling device showing a second embodiment of the present invention Side sectional view of a cooling device showing Example 3 of the present invention Side sectional view of a cooling device showing Example 4 of the present invention The perspective view of the cooling device which shows Example 5 of this invention. 6 is a side sectional view of FIG. The perspective view of the cooling device which shows Example 6 of this invention. A perspective view showing a conventional cooling device Side sectional view of FIG. Sectional view showing another conventional cooling device

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Exhaust path 2 Air blower 2a Air flow 3 Heat generating body 4 Sound pressure distribution 5 Electronic device 11 Slit 12 Porous material 13 Reflecting plate 14 Partition plate 15 Micro hole 16 Space

Claims (7)

In the cooling device comprising a discharge path provided around a heating element in the apparatus and a blowing means provided at one end of the discharge path for cooling the heating element by an air flow of the blowing means,
A cooling device comprising a slit on a side surface of the discharge path. In the cooling device for cooling the electronic device device by discharging the air staying inside the electronic device device to the outside of the device, which consists of a blowing unit provided in the electronic device device and a discharge path provided in the blowing device.
A cooling device comprising a slit on a side surface of the discharge path.   The cooling device according to claim 1, wherein the slit has a louver shape that makes it difficult for wind to escape to the outside.   The cooling device according to claim 1 or 2, wherein the member forming the discharge path is a porous material. In the cooling device comprising a discharge path provided around a heating element in the apparatus and a blowing means provided at one end of the discharge path for cooling the heating element by an air flow of the blowing means,
A cooling device comprising a reflection plate for changing an air flow in a lateral direction by providing a gap with an end of the discharge passage at an outlet of the discharge passage. In the cooling device comprising a discharge path provided around a heating element in the apparatus and a blowing means provided at one end of the discharge path for cooling the heating element by an air flow of the blowing means,
A cooling device characterized in that a partition plate having minute holes is provided in the longitudinal direction inside the discharge passage.   An electronic device comprising the cooling device according to claim 1.

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