JPH11145661A - Air cooler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize low power consumption, a low noise and savings in space. SOLUTION: A piezoelectric device 4 in the form of a plate is disposed in such a way that it can be deformed in the proximity of an inner surface 10 of a housing 8 of an apparatus to be cooled approximately in parallel to the inner surface 10 and is covered with a rubber sheet 6. The whole perimeter of the rubber sheet 6 is fixed to the inner surface 10 of the housing 8 almost without gap. When a voltage is periodically applied to the piezoelectric device 4, the piezoelectric device 4 bends and vibrates. As the piezoelectric device 4 vibrates, the rubber sheet 6 covering the piezoelectric device 4 repeats swelling toward the inside of the housing 8 and constriction in the reverse direction. In result, the volume of the space in the housing 8 changes. When the rubber sheet 6 swells in the above way and the volume of the space is reduced, high- temperature air in the housing 8 is ejected outside the housing 8 through a breather. On the other hand, when the rubber sheet 6 shrinks as stated above and the volume of the space is reset, low-temperature air outside the housing 8 is sucked inside the housing 8 through the breather.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air cooling device which is mounted on a device to be cooled and which cools the device by discharging air inside the device and sucking air into the device through a vent.

[0002]

2. Description of the Related Art For example, when an electronic device is air-cooled, one of the following two methods has conventionally been adopted. The first method is by natural heat radiation. In other words, heat generated from various heat sources in the housing of the electronic device is conducted to the air inside the housing around the heat source, and the air that has absorbed the heat passes through the vent formed in the housing by natural convection. Go to Further, heat from the heat source is conducted to the housing directly or through some member, and is radiated to the outside from the outer surface of the housing. As a result of such natural heat dissipation, the electronic device is cooled. The second method is by forced air cooling. That is, the electronic device is cooled by mounting a fan, for example, in the vicinity of a vent formed in the housing, and forcibly discharging the high-temperature air that has absorbed heat in the housing to the outside of the housing.

[0003]

However, in the first method, natural convection in the housing is not effectively generated depending on the structure, and the surface area of the housing is smaller than the calorific value in the housing. In such a case, it is difficult to secure a necessary cooling effect.
On the other hand, in the second method, since a fan is used, electric power is required, there is a problem that noise is generated, and a space for disposing the fan must be secured. The present invention has been made to solve such a problem, and an object of the present invention is to provide an air-cooling device that can obtain a sufficient cooling effect, consumes low power, does not generate noise, and does not require much space. Is to do.

[0004]

In order to achieve the above object, the present invention is mounted on a device to be cooled, and discharges air inside the device and sucks air into the device through a vent of the device. An air cooling device for cooling the device was configured as follows. In other words, by supplying electric energy, the plate-shaped deformable member that bends and vibrates can be deformed by bringing the plate surface close to the inner surface of the housing of the device to be cooled and making the plate surface substantially parallel to the inner surface. The flexible sheet member was disposed so as to be in close contact with the deformable member, and the deformable member was covered with the sheet member, and the entire peripheral portion of the sheet member was fixed to the inner surface of the housing with substantially no gap.

[0005] By supplying electric energy to the deformable member, the deformable member can be bent and vibrated. With this vibration, the sheet member covering the deformable member bulges inward of the housing, And degeneration in the opposite direction is repeated. As a result, the volume of the space in the housing changes, and when the sheet member expands as described above and the volume of the space decreases, the high-temperature air in the housing is discharged out of the housing through the ventilation port. On the other hand, when the sheet member contracts as described above and the volume of the space portion returns to the original state, low-temperature air outside the housing is sucked into the housing through the vent.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic sectional side view showing an example of an air cooling device according to the present invention. This air cooling device 2
Includes a piezoelectric element 4 and a rubber sheet 6. The piezoelectric element 4 is formed in a rectangular plate shape, bends and vibrates when a voltage is applied, and approaches the inner surface 10 of the housing 8 of the device to be cooled, and makes the plate surface substantially parallel to the inner surface 10. It is arranged. An opening 12 is formed in the housing 8, and the piezoelectric element 4 is arranged so as to face the opening 12 and cover the opening 12. One end 14 of the piezoelectric element 4
Is fixed to the inner surface 10 of the housing 8 in a state where the piezoelectric element 4 is deformable, and the other end 16 is in contact with the inner surface 10 but is a free end. The rubber sheet 6 includes the piezoelectric element 4
A little wider, the piezoelectric element 4 is covered almost in close contact with the piezoelectric element 4, and the entire periphery of the rubber sheet 6 is fixed to the inner surface 10 of the housing 8 with almost no gap, preferably without any gap. FIG. 2 is a schematic perspective view showing the entire electronic device to which the air cooling device 2 is attached. The air cooling device 2 is an electronic device 1
8 is mounted on one side wall 20 of the housing 8, and the other side wall 22 is provided with a vent 24.

Next, the operation of the air cooling device 2 configured as described above will be described. When no voltage is applied to the piezoelectric element 4, the piezoelectric element 4 is not deformed and is almost flat as shown in FIG. On the other hand, when a voltage is applied to the piezoelectric element 4, as shown in FIG. At this time, the rubber sheet 6 in close contact with the piezoelectric element 4 is pushed by the piezoelectric element 4 and swells inward of the housing 8.

Then, a voltage is periodically applied to the piezoelectric element 4, and the piezoelectric element 4 is periodically bent and vibrated. As a result, with this vibration, the rubber sheet 6 covering the deformable member repeatedly swells inward of the housing 8 and contracts in the opposite direction. Therefore, when the volume of the space in the housing 8 changes and the rubber sheet 6 expands as described above and the volume of the space decreases, the arrow A in FIG.
As shown by, the high-temperature air in the housing 8 is
4 and is discharged out of the housing 8 while the rubber sheet 6
When the space has returned to the original volume as described above, the low-temperature air outside the housing 8 passes through the ventilation port 24 as shown by the arrow B in FIG. It is sucked into 8. As a result of repeating the discharge of the high-temperature air inside the housing 8 and the suction of the low-temperature air outside the housing 8, the electronic device 18 is effectively cooled.

In the air cooling device 2, the piezoelectric element 4
, The required power is less than that of a fan or the like. In addition, since the piezoelectric element 4 only needs to be vibrated at a relatively low cycle, noise like a fan does not occur.
Moreover, since the whole is a flat plate, no space is required.

In this embodiment, the piezoelectric element 4
Is located in the opening 12 as desired.
The present invention is also effective when no is formed. FIG.
FIG. 4 is a schematic cross-sectional side view showing a case where the piezoelectric element 4 is arranged at a position where the opening 12 is not formed. That is,
An opening is not formed in this wall portion 26 of the housing 8, and the air cooling device 2 is formed on the inner surface 10 of this wall portion in the same manner as described above.
Is installed. Also in this case, by applying a voltage, the piezoelectric element 4 is deformed as shown in FIG. 6, and the air can flow as described above to obtain a cooling effect. However, when the opening 12 is not formed as described above,
In the space between the rubber sheet 6 and the inner surface 10, the piezoelectric element 4
When is curved, the pressure becomes lower, so that the deformation of the piezoelectric element 4 is slightly suppressed. Therefore, from the viewpoint of efficiently vibrating the piezoelectric element 4, it is preferable that the opening 12 is formed as shown in FIGS.

Next, a second embodiment will be described. FIG. 7 is a schematic cross-sectional side view showing the air cooling device of the second embodiment. In the figure, the same elements as those in FIG. 1 are denoted by the same reference numerals, and a description thereof will be omitted here. The air cooling device 28 differs from the air cooling device 2 in that a bimetal 30 is used as a deformable member. The bimetal 30 is formed by laminating first and second metal plates 32 and 34, and is formed in a rectangular plate shape like the piezoelectric element 4, and is close to the inner surface 10 of the housing 8 of the device to be cooled. The plate surface is disposed substantially parallel to the inner surface 10.

In such a configuration, the bimetal 30
When power is supplied to the bimetal 30, the bimetal 30 generates heat and the temperature rises.
As a result, it bends as shown in FIG. When the energization is stopped, the heat generation stops, and the temperature returns to the original flat state. Therefore, also in this case, by periodically energizing the bimetal 30, it is possible to vibrate similarly to the piezoelectric element 4, and to discharge high-temperature air inside the housing 8 and low-temperature outside the housing 8. By repeating the suction of the air, the electronic device can be cooled effectively. The air cooling device 28 also only drives the bimetal 30, and thus requires less power than a fan or the like. Further, since the bimetal 30 need only be vibrated at a relatively low cycle, noise such as that of a fan does not occur. Moreover, since the whole is a flat plate, no space is required.

Next, a third embodiment will be described. FIG. 9 is a schematic cross-sectional side view showing an air cooling device according to the third embodiment. In the figure, the same elements as those in FIG. 1 are denoted by the same reference numerals, and a description thereof will be omitted here. The air cooling device 36 differs from the air cooling device 2 in that a shape memory alloy 38 is used as a deformable member.
Like the piezoelectric element 4, the shape memory alloy 38 is formed in a rectangular plate shape, and is disposed close to the inner surface 10 of the casing 8 of the device to be cooled, with the plate surface substantially parallel to the inner surface 10. . Further, a spring 9 is interposed between the inner surface 10 of the housing 8 and the shape memory alloy 38, and the spring urges the shape memory alloy 38 substantially in a direction perpendicular to the plate surface toward the inside of the housing 8. doing. As a result, the shape memory alloy 38 is in a curved state as shown in FIG.

In such a configuration, the shape memory alloy 3
8, the shape memory alloy 38 generates heat and its temperature rises, and the shape memory alloy 38 overcomes the force of the spring 9 and
As shown at 0, the stored original flat shape is restored. Therefore, also in this case, by periodically energizing the shape memory alloy 38, it is possible to vibrate similarly to the piezoelectric element 4, to discharge the high-temperature air in the housing 8 and to The electronic device can be cooled effectively by repeating the suction of the low-temperature air. In this air cooling device 36 as well, only power is supplied to the shape memory alloy 38, so that the required electric power is smaller than that of a fan or the like. Further, since the shape memory alloy 38 need only be vibrated at a relatively low cycle, noise like a fan does not occur. Moreover, since the whole is a flat plate, no space is required.

[0015]

In the first to third embodiments, the piezoelectric element 4, the bimetal 30, and the shape memory alloy 38 can obtain a good cooling effect by vibrating at a period of 0.1 to 1 Hz. Was. In the case of the air cooling device 2 of the first embodiment, the size of the piezoelectric element 4 is
m, vertical length is 3 cm, and vibration period is 1 Hz,
A ventilation volume of 8.1 milliliters / second was obtained, and the heat release amount was 0.2 W.

[0016]

As described above, in the air cooling apparatus of the present invention, the deformable member can be bent and vibrated by supplying electric energy to the deformable member.
The sheet member covering the deformable member repeatedly swells inward and contracts in the opposite direction. As a result, the volume of the space in the housing changes, and when the sheet member expands as described above and the volume of the space decreases, the high-temperature air in the housing is discharged out of the housing through the ventilation port. On the other hand, when the sheet member contracts as described above and the volume of the space portion returns to the original state, low-temperature air outside the housing is sucked into the housing through the vent. As a result of repeating the discharge of the high-temperature air inside the housing and the suction of the low-temperature air outside the housing, the device to be cooled is effectively cooled. And, in the air cooling device of the present invention, since only the deformable member such as the piezoelectric element is driven, the required electric power is smaller than that of the fan or the like. Also, since the deformable member only needs to be vibrated at a relatively low cycle, noise like a fan does not occur. Moreover, since the whole is a flat plate, no space is required.

[Brief description of the drawings]

FIG. 1 is a schematic sectional side view showing an example of an air cooling device according to the present invention.

FIG. 2 is a schematic perspective view showing the entire electronic device equipped with the air cooling device of FIG. 1;

FIG. 3 is a schematic cross-sectional side view showing a state where a piezoelectric element constituting the air cooling device of FIG. 1 is deformed.

FIG. 4A is a schematic perspective view illustrating a state in which air in a housing of an electronic device is discharged, and FIG. 4B is a schematic perspective view illustrating a state in which air is sucked into a housing of the electronic device.

FIG. 5 is a schematic cross-sectional side view showing a case where a piezoelectric element is arranged at a position where an opening is not formed.

6 is a schematic sectional side view showing a state in which the piezoelectric element of FIG. 5 is deformed.

FIG. 7 is a schematic sectional side view showing an air cooling device according to a second embodiment.

FIG. 8 is a schematic sectional side view showing a state in which a bimetal constituting the air cooling device of FIG. 7 is deformed.

FIG. 9 is a schematic sectional side view showing an air cooling device according to a third embodiment.

FIG. 10 is a schematic cross-sectional side view showing a state where a shape memory alloy constituting the air cooling device of FIG. 9 is flattened.

[Explanation of symbols]

2, 28, 36 ... air cooling device, 4 ... piezoelectric element, 6 ...
Rubber sheet, 8 housing, 9 spring, 10 inner surface,
12 ... opening, 24 ... vent, 30 ... bimetal,
32 first metal plate, 34 second metal plate, 38
... shape memory alloy.

Claims (7)

[Claims] 1. An air-cooling device mounted on a device to be cooled, which cools the device by discharging air inside the device and sucking air into the device through a vent of the device. By supplying, a plate-shaped deformable member that bends and vibrates is arranged in a deformable state close to the inner surface of the housing of the device to be cooled, with the plate surface substantially parallel to the inner surface, A sheet member having a property of being substantially adhered to the deformable member, covering the deformable member with the sheet member, and fixing the entire peripheral portion of the sheet member to the inner surface of the housing with substantially no gap. Air cooling device. 2. The air cooling device according to claim 1, wherein the deformation member vibrates in a substantially flat state and in a state protruding in a direction away from the inner surface of the housing. 3. The air cooling device according to claim 1, wherein one end of the deformable member is fixed to the inner surface of the housing. 4. The apparatus according to claim 1, wherein the deformable member is arranged so as to face an opening formed in the housing.
An air cooling device as described. 5. The air cooling device according to claim 1, wherein the deformable member is a piezoelectric element. 6. The air cooling device according to claim 1, wherein the deformable member is a bimetal. 7. The deformable member is a shape memory alloy, a spring is interposed between the inner surface of the housing and the shape memory alloy, and the shape memory alloy plate is applied to the shape memory alloy by the spring. 2. The air cooling device according to claim 1, wherein the air cooling device is configured to be urged in a direction substantially perpendicular to the surface.